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Über dieses Buch

This book presents the select proceedings of the 1st International 13th National Conference on Industrial Problems on Machines and Mechanism (IPRoMM 2020) and examines issues in the design, manufacture, and performance of mechanical and mechatronic elements and systems that are employed in modern machines and devices. The topics covered include robotics, industrial CAD/CAM systems, mechatronics, machinery associated with conventional and unconventional manufacturing systems, material handling and automated assembly, mechanical and electro-mechanical systems of modern machinery and equipment, micro-devices, compliant mechanisms, hybrid electric vehicle and electric vehicle mechanisms, acoustic and noise control. This book also discusses the recent advances in the integration of IoT and Industry 4.0 in mechanism and machines. The book will be a valuable reference for academicians, researchers, and professionals interested in the design and development of industrial machines.



Compliant Mechanism


Jacobian-Based Inverse Kinematics Analysis of a Pneumatic Actuated Continuum Manipulator

In recent times, the use of continuum manipulators is increased in a variety of fields such as surgical operations and industrial applications. So far, multiple approaches have been developed for the Forward Kinematics (FK) modelling of these kinds of manipulators. However, the same kind of rapid development has not been successful for Inverse Kinematics (IK) modelling. So, in this paper, IK modelling for a class of continuum manipulators having serially connected sections is attempted. To accomplish this, the FK model is derived using the Constant Curvature Model (CCM). From the manipulator workspace, the desired trajectory is chosen for the inverse kinematics solution. The inverse solution is determined by applying the differential kinematics and pseudo-Jacobian inverse method. This method particularly uses a first-order resolved rate algorithm having a weight matrix and a gain matrix. Using the IK model, the variation of actuator lengths and the position of the end effector are studied on the Compact Bionic Handling Assistant (CBHA) of Robotino-XT. The effect of the weight values and the gain values is also studied. It is observed that, in general, an increase in the gain values improves tracking, whereas the weight values do not affect tracking ability much.

Mrunal Kanti Mishra, Sambaran Ghosal, Arun Kumar Samantaray, Goutam Chakraborty

Path Curvature Theory: A Classic and Effective Design Tool

Three applications of kinematics curvature analysis are herein discussed. The first one is related to the stability of lifting rigs, the second to the design of centrifugal tautochrone dampers, and the third one to the analysis of compliant linkages.

Mattia Cera, Marco Cirelli, Ettore Pennestrì, Pier Paolo Valentini, V. R. Shanmukhasundaram

Recent Developments in Higher Path Curvature Analysis

The mechanical generation of curves is a classic topic in kinematics. Although the use of linkages for solving math problems through curve tracing is nowadays obsolete, the approximation of curves employing mechanisms maintains an industrial interest. The generalized Burmester points concept, discovered by Freudenstein in 1963, provides the theoretical background to achieve high accuracy in curve approximation for prescribed values of curvature ratios. However, the numerical computation of such points, based on the solution of a polynomial system of equations, was not without difficulty. In this paper, some developments on the kinematic of planar infinitesimal displacements are outlined. One of the progress made involves the computation of the generalized Burmester points as well as other noteworthy kinematic loci.

Mattia Cera, Marco Cirelli, Ettore Pennestrì, Pier Paolo Valentini, V. R. Shanmukhasundaram

Jump Phenomena in a Motor-Driven Quick-Return Mechanism that Excites the Base of a Vibrating Structure

Quick-return mechanisms are used to reduce the non-machining time (idle time) in some machining applications so as to improve machine productivity. This paper analyzes the dynamics of a DC motor-driven quick-return mechanism, the slider end of which is linearly coupled to a vibrating mass. It is observed that around resonance, a steady and consistent increase in motor power does not result in a proportionate increase in motor speed. Instead, the motor speed increment slows down noticeably, with the bulk of the supplied motor power diverted toward the adjacent vibrating structure. This results in the operating speed getting captured at multiple resonance zones. The mechanism is able to escape the successive capture zones only when the drive power is increased beyond some critical value. This escape from resonance occurs through a series of discrete jumps. The jumps imply that it is impossible to have steady-state operations in speed ranges near the structural resonant frequencies. Consequently, the mechanism loses out on some range of intermediate speeds. Additionally, the resonance capture at lower speed ranges also leads to an overall increase in the non-machining time, thus negatively affecting machine productivity. The jump phenomena predictions are theoretically derived from a steady-state analysis of the machine dynamics.

Anubhab Sinha, Saurabh Kumar Bharti, Arun Kumar Samantaray, Ranjan Bhattacharyya

Real-Time Trajectory Estimation of a Ball Moving in a 3D Space

In modern robotic systems, computer vision systems are being incorporated on a large scale. Vision systems provide robots the ability to perceive and understand the surrounding environment for navigation and manipulation tasks. Object detection and tracking are the most common and challenging tasks accomplished using vision systems. This paper aims to develop a vision system for a robot arm for a ball-catching task using a stationary depth camera. A Kinect camera is used for this purpose. An algorithm is proposed for detecting and tracking the thrown ball. Since the camera is stationary, the moving objects in the scene are segmented from the background using background subtraction. The compactness ratio is used to separate the ball from other moving objects in the scene, and the ball centroid is obtained using blob analysis. The 3D trajectory of the ball is estimated using time-series analysis. Time-series analysis creates a model of the system which forecasts the ball coordinates in the future using past data points, i.e., the ball coordinates tracked over time. The results obtained in ball detection and trajectory estimation are then compared with other methods.

Dheeraj Bhogisetty, Sai Surya Srinivas Kunapuli, Shital S. Chiddarwar

Design and Trajectory Optimization of Delta Robot

Delta robots are parallel robots that allow the movement of an end-effector platform parallel to a base. These robots are extensively used for pick-and-place applications in the packaging industry and high precision assembly operations in electronics and 3-D printers as these have capability for high-speed operations. The robot has 4-DOF with three translational joints and one rotational joint. The paper attempts to determine an optimum path, given the start and end points of the end-effector of a virtual delta robot, and to minimize the energy consumed by the motors to drive the platform. In addition, it synthesizes a configuration that consumes the least energy while traversing a given path.

Kunal Nandanwar, B. K. Rout

Sustainable Model for Mechanization of Peppermint Oil Extraction Plants for Rural India

Peppermint leaves are cultivated and used all over the world. In India, the traditional method of peppermint oil extraction, post harvesting, used is unsafe, very laborious and less profitable. After surveying various districts of Uttar Pradesh state (India) like Sitapur, Bahraich, Barabanki, Ramnagar, etc., a solution to the existing problems is presented by developing a mechanized model. The major problems, that still exist, are the laborious method of handling the boiler drum, leave compression method and the hazardous way of burnt leaves removal from the boiler. In this paper, a sustainable model is developed to overcome the traditionally existing method in the plants of rural India. The proposed model is economical and farmer-friendly. The old and traditional method is also analysed and compared with the proposed model. This model will be helpful in providing a feasible solution to Rural India. It reduces labour cost and time to compress and remove burnt leaves.

Mohd Anas, M. Abdullah Mujeeb, Anurag Sharma

Vibration Isolation in Six Degrees of Freedom Using Combined Passive and Active Isolation Technique

Low-frequency vibration isolation in all six degrees of freedom has been a requirement in many space and other applications. The traditional linear vibration isolators are not suitable for low-frequency isolation. A nonlinear vibration isolator with the characteristics of high static and low dynamic stiffness (HSLDS) conceived by the idea of negative stiffness using magnetic spring is employed for the purpose of low-frequency isolation. To realize the six dof isolation, a Stewart isolator with its struts designed based on the quasi zero stiffness (QZS) concept is used. The effect of struts deformation on the movement of the upper plate is known by performing kinematic analysis in the cubic configuration arrangement of the Stewart platform. Equations of motion are derived using Lagrange’s equation, and simplifications are done to reduce the computational effort. By performing the Numerical simulation, the transmissibility plots are developed and compared with the traditional system and the merits are highlighted. An active control is included to increase the isolation region and decrease the resonant amplitude which are limited by the parameter of the negative stiffness and making the system hybrid. Active control is achieved by using constant and integral force feedback. In active control, the constant force feedback decreases natural frequencies and the integral part will induce damping and decreases the resonant amplitude. The results from active control are compared with passive one giving a better isolation region and decreasing the resonant amplitude.

T. Akshay Kumar, B. Santhosh

Evolution of Three Hold-Down Configuration for Large Antenna Mounted on a Dual Axes Steerable Mechanism

The Hold-down system is a key unit on satellite that enables rigid holding of antenna on to the spacecraft structure so as to withstand diverse loads during launch. The hold-down system gets released on orbit upon actuation command so that the antenna gets deployed to its functional orientation using various mechanisms. Thus, the configuration of the hold-down system is very critical in fulfilling the overall satellite mission. The configuration of the hold-down system primarily involves arriving at the required number of hold-downs, which depends upon several factors like stowed frequency requirements, mass, inertia, and size of the antenna. In the present work, an iterative approach has been adopted, by varying the number of hold-downs and span between them, in order to meet the satellite specifications related to large steerable antennae. Based on normal mode frequency analysis, several parametric studies have been carried out to meet the stiffness requirements while catering to mass and space constraints of satellite mission. Finally, after detailed studies, a three hold-down configuration has been arrived at for large antennae. This paper presents the evolution of this three hold-down configuration along with details on different case studies carried out and the corresponding reasons for considering the cases. The configuration has been devised so as to meet the frequency requirements of spacecraft along with confirmation of hindrance free release of the antenna after deployment, desired nominal functional movement of the antenna, and ease of assembly and testing. The FEA details of different cases along with the optimum configuration with three hold-downs integrated onto antenna bracket that has been arrived and have been presented. The methodology adopted for finalization of the hold-down configuration serves as guideline for arriving at an optimized solution for rigidly holding a large sized steerable antenna on spacecraft.

Saurabhkumar H. Patel, V. Sri Pavan Ravichand, Anoop Kumar Srivastava, S. Narendra, A. Shankara, H. N. Suresha Kumar

Workspace Analysis of a 5-Axis Parallel Kinematic Machine Tool with 3-RRS Parallel Manipulator

Parallel Kinematic Machine (PKM) because of its interesting alternative designs and versatility has gained a lot of interest in many industrial applications and in production lines especially in high-speed machining applications since they offer a number of advantages over the serial manipulators like better accuracy, higher structural rigidity, higher agility and improved dynamic characteristics. Conventional PKMs are designed to have 3-Degree of Freedom(3-DoF) movement of the moving platform; however, in this work, two additional DoF have been incorporated in the form of movement of the base in X and Y directions. The configuration of the 3-DoF parallel manipulator (PM) used here is 3-RRS with 1T2R type of motion of moving platform. This paper presents a type of 5-axis PKM tool architecture on which the 3-RRS PM having 3-DoF motion slides on the frame structure of the machine tool along X-direction and Y-direction providing extra 2-DoF. Complete position level kinematic analysis is carried out and the workspace analysis of this mechanism is proposed in this paper. This workspace analysis shows the reachable work volume of the end-effector and enables to know the complete reach of the tool required for the complex industrial applications and machining operations. A quantitative improvement in reachable work volume over conventional 3-DoF PKM is presented.

Anshul Jain, H. P. Jawale

Four-Bar Linkage Mechanism in Papermaking and Its Replacement by Direct Servo Drive Technology in Roll to Sheeting Lines in a Paper Mill—Converting House

Till the 1950s & till Grashof law was applied, Roll to sheeting Equipment manufacturers were not able to develop Dual rotating Knives sheeters. Till then, it was either Guillotine shears with production speed limitations or a Single rotating knife with output defects. Dual rotary knife machines became successful only with the Adaptation of Four-bar linkage mechanisms (Double Drag link) for avoiding parallelogram defects, for achieving diagonal length and cut length accuracies of <  ±0.5 mm of the set lengths, and for achieving higher production speeds at 100 mtrs/min. New servo drive technologies in both AC and DC saw the emergence of machines with more accurate performance, at higher productivity, and the highest machine uptime availability.This paper starts with the application—the principle of operation, the machine requirements with examples and method of implementation of the four-bar linkages employed, and the performances achieved including a brief on Mechanical transmission elements earlier employed with few illustrations. The paper also details the development and evolution of Low inertia DC Motor servo drive technology in the 1970s, finding its best application in the Sheeting equipment. Subsequent developments in AC servo drive facilitated extensive adaptation in the application with the giant strides AC drives and motion control algorithms post the millennium year 2000 AD. This in conjunction presents the Feed Forward control algorithm deployed in the application also is briefed including comparison with other algorithms with the main advantage of acceptance of Low MOI prime movers and higher MOI mismatch going up to 20:1, i.e., load MOI: Prime mover MOI in such applications. The effective use of technology had yielded the best accuracies to the tune of ±0.38 mm in a cut length, diagonal lengths with increased productivity rates to 350 mtrs/min.The paper also compares various Cam profiles available for the application including trapezoidal, trigonometric, and quasi sinusoidal options Electro-mechanically supported with illustrations present to the audience for effective selection of apt profile. Links to videos depicting the application with a modern state of technology in Fine Paper, Paper board, and Corrugation, Steel industrial sectors are included in the paper.

Muralidhar Ekambaram

Robotics, Industrial CADCAM Systems, Mechatronics


Two Degree-Of-Freedom Omni-Wheel Based Mobile Robot Platform for Translatory Motion

Mobile wheeled robots are used for various applications such as moving payload from one place to another. In many instances, the orientation of the robotic platform does not change and hence for those applications, it is desired to have platforms that just have translational degrees-of-freedom and do not have a rotation about the vertical axis (yaw rotation). In this paper, the authors propose two architectures of the platform that have two active and two passive wheels. Simulation in V-REP software was carried out and physical prototypes were developed and tested to validate the effectiveness of the proposed platforms. One of the proposed designs fits perfectly for a pure translation mobile platform.

Uday Manne, Raghuveer Maddi, Dimple Dannana, Devasena Pasupuleti, Rajeevlochana G. Chittawadigi

Kinematic Error Modeling of a Parallelogram Arm of the Delta Robot and Its Dimensional Optimization

Delta robots are a subset of a class of robots called parallel robots. These are widely used in pick-and-place and assembly tasks involving high motion accuracy. The basic idea for the design is the development of parallelogram structures attached to the output platform. Three such parallelogram mechanisms are used to ensure that the orientation of the moving platform is restricted to only translational motion relative to the base. This paper aims to improve the robot’s motion accuracy by performing a study on the parallelism error and verify its influence on accuracy. Previous studies on the error analysis in the motion of Delta robots mainly consider dimensional tolerance, joint clearance and driving error of each component, mainly focusing on the position error of the moving platform. However, the analysis of the parallelogram arm is also equally important to ensure minimum posture error to reduce the pose error(orientation + position) of the mobile platform. Any posture error in the mechanism results in the posture error of the moving platform. This article approaches to reduce this posture error by considering the main influencing factors-length error in the connecting rods and joint errors in the parallelogram mechanism. The work is divided into two sections. The first section deals with the kinematic analysis and estimation of optimum dimensions. The second section deals with the error analysis using the kinematic approach. This section also relates the errors of pose and structural types. And, due to its analytical nature, this error model can be used for sensitivity analysis to further enhance manipulator accuracy.

Venkata Sai Prathyush Idumudi, Arshad Javed

Design and Control of Mobile Robots with Two and Four Independent Rotatable Power Wheels

This paper analyses two kinds of models for Mobile robots having two and four independently rotatable power wheel configurations, respectively. Both the models were analysed for performance based on mechanical design and kinematic control aspects. A scissors mechanism was employed on the robots to equip them with weight lifting capabilities which are controlled by a linear actuator. The robot can be used for various purposes including inventory management, shop-floor assistance and warehouse automation. In the end, a simple computed velocity control kinematic model was developed for both the models and results were compared.

Divyansh Khare, Kausadikar Varad Prashant, Santhakumar Mohan

Analysis of a 4-DOF 3T1R Parallel Robot for Machining Applications: A Stiffness Study

This paper provides a comparative kinematic and stiffness analysis between two parallel robots for machining/CNC applications. One of them has the acknowledged 3-DOF 3T motion. The other one has 4-DOF 3T1R motion, also known as Schönflies motion. The proposed analysis first describes the robots’ kinematics, including position and differential kinematics. Afterward, a theoretical structural stiffness analysis will be provided. Then, some discussions regarding which robot presents better machining application properties are conducted. Finally, some drawbacks are appointed, and possible strategies are proposed in order to overcome these limitations.

Paulo Rossi, Roberto Simoni, Andrea Piga Carboni

Modelling and Simulation of Industrial Robot Using SolidWorks

The work presents the evaluation of the motion analysis of the KUKA KR6 industrial robot. The motion analysis module in SolidWorks includes various options to measure the velocity, torque and displacement of industrial robot and provide graphical results in SolidWorks software. The kinematic model provides the end-effector position in the spatial workspace by using the standard Denavit–Hartenberg parameters. The visualisation of robot task planning is quite difficult for the robot technicians. The improper planning and the lack of visualisation of the tasks or events increases idle and training time. The modelling and simulation of KUKA KR6 were performed with the support of SolidWorks software. The event-based motion analysis module is used to plan the path or task related to the industrial robot to study the motion of joints and links for better performance of the robot. The robot arm trajectory is plotted to trace the end-effector movement of KUKA KR6 created in event-based motion analysis. The event-based motion analysis helps offline programming and visualisation of the robot in various applications and eliminates the lack of visualisation for robot technicians.

Chinmaya Sabnis, N. Anjana, Amit Talli, Arunkumar C. Giriyapur

Machinery Associated with Manufacturing


Long-Range Drilling System with Constrained Tool Path Based on Scissor-Like Elements

The drilling system presented in this work offers the possibility of reaching a long machining range, in addition to constraining the tool path. In this system, a displacement mechanism, based on scissor-like elements (SLE), is being used, which is able to cover a greater range compared to conventional drilling machines. The constraints on the tool path are regulated by a model-based predictive controller (MPC). This controller in addition to stabilizing, restricts overshoot and limits the advance of the tool.

Juan G. Grijalva, Edson R. De Pieri, Daniel Martins

Development of an Automatic Thread Tension Adjusting Device for Single Needle Lock Stitch Machine

Apparel manufacturers have to continuously upgrade their existing machinery to deliver the perfect quality and also minimize wastage due to production defects. One of the major challenges is to obtain the perfect stitch, which is ensured when both the interlocking needle thread and bobbin thread have balanced tension. Uneven tension results in defects like broken stitches, thread breakage, seam grin, seam puckering, etc. Maintenance workers are assigned to inspect and tune the line layout during changeovers using a conventional trial and error method. This results in a significant loss of production time. The problem can be solved by developing a device that can monitor and adjust the needle thread tension in real-time and the bobbin thread tension during the bobbin winding process. Such a device has been designed and the working prototype has been developed. It is a mechatronic device that has been developed exclusively for single needle lock stitch (SNLS) machines. The prototype has been successfully tested using different fabrics. Estimates reveal that retrofitting using this device could drastically reduce stitching defects and increase overall productivity.

Bhaskar Guin, Rohan Roy

Bearing Fault Diagnosis in Induction Motor Using Modified AlexNet Algorithm

The coming decade is expected to be the decade of the fully electric car. In India, most of the electric vehicles use a three-phase induction motor for propulsion. The all-electric type of vehicle depends on the motor for the propulsion. Thus, it is essential to monitor the health of the prime components in the motor. The bearing fault is responsible for 40–45% failure of the induction motor. Health monitoring of rolling element bearing can avoid the catastrophic failure of the induction motor. The paper presents a modified AlexNet deep neural network for the bearing fault diagnosis using the time-frequency plot of the vibration signal. A deep neural network can automatically extract the features from the provided image dataset. To simulate the real-life condition of electric vehicle vibration, the desired level of noise is added in the acquired vibration signal. The conventional machine learning technique involves the selection of the features from the acquired features set based on the importance of the feature, while the deep learning technique automatically calculates the features from the provided image datasets. The proposed technique can improve fault diagnosis accuracy compared to conventional machine learning techniques. Implementing the proposed technique with an onboard diagnostics can indicate the health of the bearing in the induction motor.

Swapnil K. Gundewar, Prasad V. Kane

Improved Design and Development of Crop Conveying Mechanism in Reaper Machine

Mechanization of agriculture plays an important role for improved crop productivity. In harvesting, machines reaper is used to harvest wheat crops. In the existing machines, there is a need to improve the crop conveying mechanism which can also uplift the slant crops occurred due to wind and nature occurring problems. Thus, in this paper, an improved mechanism is proposed which can contribute to increase the efficiency of the machine. Kinematic analysis is also performed to validate and compare the experimental to design data. Torque required to run the crank is also identified in this work through dynamic analysis. Finally, a prototype was developed through 3D printing.

Anand Kumar Jangir, Narendra Achera, Saurav Khandelwal, Chirag Gupta, Himanshu Chaudhary, N. R. N. V. Gowripathi Rao

Ergonomic Workstation Design for Welding Operation—A Case Study

Ergonomic Design of a workstation is a need of time to overcome the future issues of Musculoskeletal Disorders (MSDs) of workers. The industries having repetitive manual operations have become aware of the significance of the effect of the ergonomically designed workstation on the physiological and psychological aspects of a human being. Ergonomic intervention with a detailed analysis of existing operating practices in the manufacturing unit using different ergonomic analysis tools identifies the opportunities for potential improvements. This paper discusses an ergonomic analysis carried out in a welding operation of a tractor trolly manufacturing unit located in central India. The ergonomic tool such as Rapid Upper Limb Assessment (RULA) is applied to identify the need for ergonomic intervention based on the RULA scores. Based on the anthropometry of the Indian male, a new fixture design is proposed by introducing a tilting mechanism in it. The proposed design reduces the RULA score thereby reducing the future possible musculoskeletal issues of workers.

T. A. Madankar, P. V. Kane, D. Agrawal, S. V. Kedar

Prediction of Torque and Cutting Speed of Pedal Operated Chopper for Silage Making

This investigation was mainly carried out to develop an efficient power unit for fodder cutting using the energy of humans as a power source. In dairy, the major problem is fodder scarcity in the dry season. The cost of fodder decides the economics of the dairy business. It means that available fodder should be used without any wastage. The available machines of fodder cutting are either electrical motor or hand driven. Yet, today there is an enormous electrical power scarcity approximately everywhere in India. To overcome this, the proposed sustainable fodder cutter driven by the human power unit can provide a better substitute for electrical power-operated cutting units. This fodder cutter can be operated without exhaustion and easily for a more extended time if a hand-driven fodder cutter is supplanted by a pedal-driven. Additionally, the facts confirm that hand muscles are weak as compared to the leg muscle. This human-powered flywheel motor unit was tested under three studied variables namely gear ratio (1:2, 1:3, and 1:4), flywheel speed (300,400, 500, and 600 rpm), and the number of blades (2 and 3).

Pravin B. Khope, Sagar D. Shelare

Finite Element Modeling and Parametric Investigation of Friction Stir Welding (FSW)

Difficulty in welding of Aluminium alloy through conventional technique and requirement of light weight welded structure for the aerospace, marine and industry application led to the development of novel welding technique i.e., Friction Stir welding. Friction stir enabled additive manufacturing proved to be a solution to repair aluminium alloys used for aerospace and defence industries. In the present work, FEM model is established for the Friction stir welding analysis and results are confirmed with the experimental study. Arbitrary Eulerian Lagrangian(ALE) approach is used for the computational system to avoid large distortions in mesh around the tool. Three-dimensional nonlinear thermal numerical simulations are performed using Altair Hyper Weld Friction Stir Welding (FSW) tool for the joint of AA6061 (aluminium alloy) material plates. Thermal solutions are considered for the Welding process simulation. Furthermore, influence of various process parameters on welding of AA6061 aluminium alloys is investigated to enhance the material properties. Translation, and rotational spindle speed are the process variables considered for the study. Analysis conclude that temperature in the FSW process is symmetrically distributed along the welding line. Increase in Rotational Speed increases the Peak temperature whereas, increase in Translation speed results slight decrease in Peak Temperature. The numerical simulations obtained and validated are proposed to illustrate the accuracy of the presented methodology and its potential to study real Friction Stir welding processes. Altair’s Hyper Weld Friction Stir Welding module proved to be potential tools for the analysis of friction stir welded joints.

K. S. Mehra, S. Kaushik, G. Pant, S. Kandwal, A. K. Singh

Wear Analysis of Polytetrafluoroethylene (PTFE) Reinforced with Carbon and Bronze

Conventional oil-lubricated reciprocating air compressors use a lubricating oil to minimize the friction and piston ring wear. But this necessitates replacement of oil and oil filters at regular intervals, in addition to oil condensate treatment. Oil-free compressors minimize these operational costs, protect the environment, minimize leaks and energy costs. To achieve this, oil-free compressors use piston rings that are fabricated using dry lubricating materials like Polytetrafluoroethylene (PTFE) composites. For sustained air delivery, it becomes necessary to ensure that the rings have better tribological properties. Different hard filler elements along with solid lubricants are added to PTFE composites to upgrade their tribological properties. However, their suitability and design point particularly for compressor application are not well researched and hence continue to possess design challenge. This research investigates the methods of improving tribological properties of the PTFE composites and hand picks the best suitable composition for further analysis on real application. In this, after analyzing piston rings from different compressor manufacturers and literature survey, PTFE filled with three different filler materials (i) Carbon (ii) Bronze (iii) MoS2, with various respective content in increments is manufactured. Wear analysis is performed on the specimens on a pin-on-disc tribometer and worn out surfaces are studied using scanning electron microscope. Further, a study using design of experiment is performed to determine individual and interactive effect of load and sliding velocity on wear rate and friction coefficient. The investigation reveals that the tribological properties strongly depend on the PTFE composite content and wear disc material. The properties are distinctive with no pattern emerging out from the same material family. The results revealed that 25–35% carbon-filled PTFE has better tribological properties and is more suitable for piston ring application. Adding graphite or MoS2 does not improve both wear rate and friction coefficient simultaneously. The result also revealed that for coefficient of friction to be low, the maximum sliding velocity should be restricted.

Prasun Kumar Pandey, S. Thirumalini, R. Padmanaban, G. Jayashankkar

Modelling of a Porous Functionally Graded Rotor-Bearing System Using Finite Element Method

In the present work, a functionally graded (FG) Jeffcott rotor system, consisting of a uniform steel disc, an FG shaft and linear isotropic bearings, is considered. While fabricating an FGM, the formation of porosities is inevitable; hence it is one of the foremost imperfections to consider while assigning material properties, as well as, modelling the FG rotor-bearing system. Dynamic modelling of a porous functionally graded rotor-bearing system has been carried out using the finite element method (FEM) to compute natural frequencies. A two-noded porous FG shaft element with four degrees of freedom (two translational and two rotational) on each node has been developed using Timoshenko beam theory (TBT) by including the effects of translational inertia, rotatory inertia, gyroscopic moments, transverse shear deformation and volume fraction of porosity. An FG shaft, whose inner core is composed of metal, which is stainless steel (SS), and outer layer made of zirconia (ZrO2) is considered to investigate the effect of porosity and the power-law index on natural frequencies. A finite element code is developed using Python to calculate the radial variation of material properties, as well as, to solve the eigenvalue problem of a porous FG rotor system. The natural frequencies of the FG rotor-bearing system have been calculated for different power law indices and volume fractions of porosity. It is deduced that the natural frequencies are affected due to the influence of the power-law index and volume fraction of porosity.

Aneesh Batchu, Bharath Obalareddy, Prabhakar Sathujoda

Influence of Workpiece Mating Gap on Friction Stir Welding of 316L for Fixture Design on a Machine

The low shrinkage and less residual stress during friction stir welding (FWS) process makes it more advantageous compared to other welding processes, especially for the aerospace application materials. The weldments strength and mechanical properties are function of various input parameters such as tool pin diameter, spindle speed, traverse velocity, advancing and retracing angle of tool. The workpiece mismatch and workpiece mating gap are inherent process variation because of welding process setup. The workpiece mating gap also has a significant influence on the weldment strength. The understanding of workpiece mating gap on the temperature distribution in weldment can help in achieving the desired strength. This understanding of gap is very critical for designing a fixture for a friction welding machine. The design for fixture must have high rigidity to avoid the large variation in workpiece mating gap during the friction welding process. Consequently, the present work studies the effect of workpiece mating gap on temperature generation and distribution in welding zone by carrying out the modelling of friction welding process. The workpiece mating gap has been introduced in the finite element modelling of the friction welding process. The mating gap between the plates is considered as a percentage of tool pin diameter, varying from 0 to 25%. The heat generation in friction welding process is due to friction between the tool and the workpiece and hence, a varying contact frictional coefficient has been used in the present work for contact modelling. Stress generation and distribution is also studied and correlated with the input parameters. The simulation has been carried out with Tungsten Carbide as the tool with a rotational speed of 1250 rpm and 60 mm/min as linear velocity and this was kept constant for all the gap widths.

B. Raghu Prem, Kundan K. Singh, Ravi Shanker Vidyarthy

Integration of IoT and Industry 4.0 in Mechanism and Machines


Physics-Driven Process Digital Twins to Aid Pharma and Specialty Material Manufacturing

In any chemical process industry (pharma/specialty materials/semiconductors, etc.) with multiple unit operations, realizing the full potential of the vision of Industry 4.0 demands effective capture and utilization of relevant process data. This involves effective integration of the working of the equipment and the processes they handle. While machine digital twins link the equipment details to its operation, process digital twins link the performance of any unit operation (like mixing, drying, etc.) with the relevant properties of the process materials, the characteristics of the process equipment, and the process conditions used. Process digital twins designed by capturing the detailed process understanding are key to the Industry 4.0 paradigm. They can provide an end-user with detailed insights into the process and the ability to (a) expedite lab or plant scale product/process development to achieve the desired product by minimizing trials and errors, and (b) troubleshoot processes in real time. This study focuses on a few case studies in the development and deployment of such twins.

Jenil P. Dedhia, Ravichandra Palaparthi

EEG-Based Hand Movement Recognition: Feature Domain and Level of Decomposition

This manuscript reports feature domains for the recognition of right and left hand movements using Electroencephalogram (EEG). A 21-channel EEG dataset of seven subjects during right and left hand fist open and close movements was collected from PhysioNet of the BCI2000 Instrumentation system. Features in time, frequency, and time-frequency domains have been explored. Support vector machine with radial basis function kernel was used for the recognition of right and left hand fist open and close movements. The recognition with time, frequency, and time-frequency domain features resulted in an accuracy of 90%, 92%, 97.5%, respectively. Time-frequency domain features obtained through discrete wavelet transform (DWT) at four decomposition levels have resulted in maximum recognition rate. The highest recognition rate of 98.6 $$ \pm $$ ± 0.6 % has resulted in DWT features at level 2. This was substantiated by the fact that DWT features at level 2 establish maximum correlation with pre-processed EEG. Experimental result shows that time-frequency is the best performing feature domain among the three. Further, correlation measure of time-frequency domain features with EEG are established as a benchmark for selecting DWT decomposition level.

Nabasmita Phukan, Nayan M. Kakoty, Nipun Gupta, Neelanjana Baruah

Burr Registration Using Image Processing

With the ever-increasing demand for product quality, it is imperative to have burr-free workpiece edges after manufacturing. Burrs have intense effects due to improperly finished edges and may have large economic impacts in case of catastrophic failure. Vision-assisted robotic deburring is the most suitable and feasible deburring method. The already available image acquisition systems are not able to capture burrs at all edges of the object, and cannot accommodate objects of varying sizes. Besides, the illumination in the system and the ability to use the system in-line is a matter of concern. Thus, this paper attempts to develop an image acquisition setup that meets these objectives in acquiring the images and registering the burrs in an object. The setup captures images taken with adequate illumination from a CMOS camera mounted on a spinning ring that is controlled by an Arduino. These images are then imported in a photogrammetric software to 3D-reconstruct the object as 3D point clouds and then as polygonized mesh. It is followed by a dimensional analysis by comparing it with the CAD model of the master burr-free part using an inspection software. This helps in identifying the burrs and provides a colored measuring scale. The accuracy and reliability of burr detection and its measurement using photogrammetric technique merit the suitability of the proposed system as a non-contact and non-destructive testing method for any form of defect identification, gauging in industrial metrology, and as a potential base to an automatic quality inspection system.

Anup Pillai, Shital Chiddarwar, M. R. Rahul, Mohsin Dalvi

LoRa-Based Infrastructure for Medical IoT System

Internet of Medical Things or Medical Internet of Things (MIoT) is an emerging infrastructure to advance e-health services with the organized medical devices. In the context of Internet of Things, medical applications are considered to be a critical. With the emerging paradigm of medical IoT, it is important to improve and analyze every part of the IoT infrastructure for the development of a reliable platform. This system proposes a health IoT infrastructure using LoRa technology. Moreover, it represents the improvement and progress of current medical IoT infrastructure stating its advantages and drawbacks dedicated to medical services.

P. Muthu Subramanian, A. Rajeswari

A Robust Image Analysis Method for Cutting Tool Wear Monitoring in High-Speed Micromilling Process

An increase in demand for the dimensionally accurate miniature components necessities the micromilling process to be carried out without cutting tool wear. The micro-end mill wear monitoring is very difficult due to its micro dimension. Most of the sensors used for in-process monitoring of micro-end mill suffer from high noise issues. The machine vision system with image analysis techniques has been successfully used for macro-end mill wear monitoring. Mostly used wear measurement is the flank wear between the machined surface and the relief edge of the cutting tool, and the flank wear has been used as a criterion for macro-end mill life. The same flank wear criterion cannot be adopted for micro-end mills due to micro-end mill cutting edge wear. Consequently, robust image analysis has been analyzed in the present work to measure the cutting edge distortion. The cutting edge distortion mapping has been carried out by micro-end mill edge detection of the micro-end mill image. The image analysis has been carried out to monitor the wear of two different coatings of the micro-end mill. The first coating is of TiAlN and the second coating is of TiAlSiN. The proposed image analysis shows that TiAlN coating gives less wear compared to TiAlSiN coating for machining at 50000 rpm and 50 $$\mu m$$ μ m depth of cut. The cutting edge diameter for TiAlSiN coated micro-end mill was found to be increasing by $$51\%$$ 51 % compared to TiAlN coating. The method adopted in the present work can easily be incorporated with in-process monitoring of the cutting tool wear during the high-speed micromilling process.

Aman Sharma, Vaibhav Rathore, Brajesh Panigrahi, Kundan K. Singh

Space Applications and Modern Structures


Behavior Study of Tape Springs for Space Deployment Applications

Space deployable systems, folded during the launch of a space vehicle, need to be deployed once the spacecraft reaches its orbit, to perform its function. This simple deployment process is extremely critical for the success of the mission. Most commonly used deployment mechanisms require actuators, motors and accessories such as latch and springs. Tape springs, which are the thin booms that subtend smaller angles offer many advantages including simplicity, light weight and low cost. But more importantly, they inhibit compact folding, self-deployment and self-locking features. These advantages promote their use in deployment mechanisms, but the possibilities of hard folding due to high stress concentration limit their applications. Furthermore, they show different highly non-linear behavior when loaded in different configurations. This study presents the experimental, analytical and FEA study on tape spring subjected to transverse end loads to study and quantify the differences in behaviors corresponding to different configurations, namely “Equal” and “Opposite” sense by employing “Theory of shell structures”. An analytical approach is used to relate the displacement of free end to the moment at fold, stress and strain. A comparative study is performed with the experimental strain measurements. The Analytical strain results displayed about 9% and 19% mean absolute error (including the snap region, within elastic limit), whereas the Numerical results from FEA showed 2% and 4% variation in the strain for equal and opposite sense loading, respectively, when validated against the experimental results. From this study, it is concluded that the opposite sense loading not only results in higher deployed stiffness and higher resistance to deflection but is also more prone to higher stresses and strains for a given load after the snap and thus requires appropriate trade-offs.

Rutvik Dangarwala, Hemant Arora, Shashikant Joshi, Sudipto Mukherjee

Parametric Optimization of Joints and Links of Space Deployable Antenna Truss Structure

With the volcanic proliferation in high bandwidth communication, space-borne antennas are required to have Large Diameter Reflectors (LDR) of size 6 m or more which will cater to the requirements of high bandwidth data transmission. Space deployable antenna structures are a buzzword today which are required to occupy compact volume during launching due to space crunch in, state-of-the-art, contemporary launch vehicles. These compact geometric topologies are later deployable to the full configuration after orbit insertion. The antenna deployable mechanism consists of a truss ring structure and a flexible reflective metallic mesh supported by a net. Hinges play a vital role in folding the antenna truss to compact the volume and for the smooth deployment of a ring truss structure to its full configuration. Therefore, an optimization investigation is carried out in designing the parameters of hinge joints of AstroMesh (Thomson, M.W.: The astromesh deployable reflector. IEEE Antenna Prop. Soc. 1516–1519, 1999.) configuration. Critical parameters of joints and links are considered as design variables, and circumstances of the system are described by design constraints. An objective function is formulated on the basis of the compact volume of stowed configuration. Variation of link parameters is plotted with the size of stowed configuration. The results are also extrapolated for a 12 m diameter truss structure and compared for optimum design parameters. A volumetric efficiency of 99.7% is achieved for a 12 m diameter truss which is optimum and plotted with variation in the number of bays. This optimized deployable antenna design has the potential for launch in futuristic Indian space missions.

Hemant Arora, Vrushang Patel, B. S. Munjal, Sudipto Mukherjee

Response of a Vibratory System Under Impact Using Contact Force Models

The most important and complex parts in the analysis of impact-excited vibrations are the estimation of correct initial condition, precise instant of contact and evaluation of contact stiffness. The traditional approach involves transforming impact into initial velocity. However, the solution obtained by this approach does not consider properties of impacting bodies, geometry of contacting surfaces and duration for which force acts on the body. The approach proposed in this paper uses contact force models (both Lankarani–Nikravesh and Flores models being considered) and gives a deeper insight into addressing impact excited vibration by considering material properties of impacting bodies and geometry of contacting surfaces. The maximum response of the vibratory system obtained by using this approach differs from the one obtained by the traditional approach, and the amount of variation changes with the coefficient of restitution and the relative velocity between impacting bodies just before impact. Demonstrative examples of a spring mass system with linear and nonlinear spring and damper with impact excitation provide results to support the discussion. The approach used in the paper can be used to precisely design machine components which undergo impacts during their operation.

Deepak Maslekar, Anirban Guha, Sripriya Ramamoorthy

Failure Behaviour of a Thin Domed Steel Disc with and without Scores Under a Pressure Impulse

The domed thin steel disc can be designed to act as a sacrificial pressure relief element to burst open at a predefined pressure limit. The deformation, burst, failure pattern and burst time of this disc, under a pressure impulse generated from an air blast, is governed by its score geometry and pattern. This paper analyses the dependence of these failure parameters on the number of scores, i.e. score pattern. The effects are investigated through numerical simulations using a non-linear explicit finite element analysis based on Lagrangean method. The large strain and strain rate hardening are captured through a visco-plastic constitutive model and damage through a continuum damage mechanics based Johnson–Cook model. This study reveals that a number of scores either 2, 3 or 4 may be preferred as far as the low responses in burst parameters are concerned but the selection of a particular number of scores between 2 and 4 depends on the choice of a designer in consideration with other design requirements.

K. Gopinath, V. Narayanamurthy, Y. V. D. Rao

Development of Shape Memory Alloy (SMA) Based Hold-Down and Release Mechanism for Space Applications

Antenna and solar panels are initially folded to reduce their size during the launch of a space vehicle and later deployed to a full configuration in space to accomplish its task. The release mechanisms are particularly useful to securely store space deployable systems in a launch vehicle and then provide safe and stable deployment in space. The currently used release mechanisms have some disadvantages like the use of hazardous explosives which are not safe to handle multiple times before launch, produces shock pulses which may harm other adjacent electronic/optical subsystems and these are not reusable for ensuring operational reliability during ground-level testing before launch. These disadvantages are overcome by the use of Shape Memory Alloy (SMA) which is proposed as a viable solution. The working principle of SMA materials is based on the Shape Memory Effect (SME) which is heated above its phase transformation temperature to regain its memorized shape. SMA-based hold-down and release mechanism is designed meeting with design constraints of simple design, compact in size, lightweight, low shock, reusable, easy to reset, and high operational reliability. Design of springs, SMA wire loop, and other components are optimized to meet the desired actuation force and holding stiffness requirements. A repeatability test is carried out with 100 test operations with no degradation of parameters confirm its operational reliability for space use. The tensile test shows that the release mechanism can sustain a holding load of 1509 N which proves its ruggedness for sustaining the space launching dynamic loads.

Harshkumar Patel, Hemant Arora, Shashikant Joshi, Sudipto Mukherjee

Applicability of Low-Cost Duct-Shaped Wind Turbine for Domestic Purpose and Low Wind Speed

Modern household energy consumption has increased significantly because of various lifestyle factors from gadgets to electric vehicles and thereby exhausting natural resources like fossil fuels which are used conventionally for generating electricity and also contributing to environmental pollution. So, the production of energy through renewable energy sources, such as wind, and solar, has been encouraged globally by the Government with the aid of subsidies. This paper addresses the essence of energy production through wind for domestic purposes with a funnel-like duct-shaped arrangement for wind turbines. The air is taken into the duct-shaped wind turbines omnidirectionally without the requirement of a separate mechanism. The duct shape fulfills the purpose of concentrating and increasing the velocity of wind onto the wind turbine. This has a significant effect on the power generation because the output power generated is directly proportional to the wind velocity of cube power. These innovative systems generate electricity even for the low wind speed with a minimal cost setup. This paper discusses a prototype of the proposed system design which can be assembled using locally available material in a day or two. This is capable of producing 0.5 to 0.6-unit electricity per day. The prototype was tested and results were validated by using simulation results in CFD FLUENT

S. V. S. K. Prasad Raju, M. Govindaraju, T. Satish Kumar

Bio-medical Devices and Bio-mechanisms, Devices for Aerospace, Automobile and Railways


Novel CAM Mechanism-Based Life-Support Ventilators in Animal Healthcare

Mechanical ventilation is a way of providing respiratory support for animals which are unable to breathe or oxygenate on their own. It is used for a wide variety of conditions and situations. A mechanical ventilator does not cure any disease or conditions but aids in the function of treatment by supporting the process of respiration. The ventilators must also work with high level of accuracy, as even a small mistake can cost a life. The existing ventilators in the field remain expensive, making it inaccessible to small-scale hospitals, and further a demand for a simplified yet effective ventilator always exists. This project deals with the development of an alternate low-cost electronically controlled stand-alone mechanical system to effectively control the rate and waveform of air in animal life-support ventilator systems. The Frustum CAM (FC) mechanism—a first of its kind, patented mechanism which uses the concept of Variable Valve Lift (VVL) to control the lift of valve, thereby controlling the flow rate of air. By effectively developing the FC ventilator system or by integrating it to the conventional ventilators using proper supporting system, the cost can be cut down to a great extent and yet high flow control can be achieved.

Prem Dakshin, Shashank Khurana

Multi-body Topology Optimization of Connecting Rod Using Equivalent Static Load Method

Topology optimization technique is employed to optimize mechanical components of various mechanisms and internal combustion (IC) engines to improve the dynamic performance and minimize the overall weight of the system. Specifically, in IC engines, connecting rod is a critical component, which experiences high dynamic loadings with significant stresses. Connecting rod along with piston contributes much to exaggerating the unbalancing of the engine. Thus, weight reduction of a connecting rod is attempted in the present work, with a volume fraction value ranging from 0.3 to 0.9. The entire model of the IC engine is designed using SOLIDWORKS 2019 software and imported into Altair Inspire multi-body simulation software to analyze the motion study. Being operated in a dynamic situation, the boundary forces are considerably fluctuating. Thus, a static topology optimization process will not be sufficient as the optimal topology is a function of boundary force direction. Here, the boundary conditions of the connecting rod, such as forces and torques are analyzed using an equivalent static load method, which is used as dynamic load cases for topology optimization process. The topology optimization is conducted for the connecting rod at various volume fractions, maximizing the stiffness or minimization of compliance as the objective function. To obtain the better manufacturability of the topology, shape controls of the geometry are applied as symmetry and split draw. The obtained topology is analyzed to capture performance values such as maximum deflection values and Von-Mises stress. For volume fraction 0.7, the weight is reduced by 30%; the performance of deflection and Von-Mises stress are reduced by 11.09% and 14.42%, respectively.

G. Lakshmi Srinivas, Arshad Javed

Challenges in the Design of a Laparoscopic Surgical Forceps

The paper introduces the challenges faced during the development of new laparoscopic surgical forceps carried out in the design, manufacturing aspects, and implementation. The designed laparoscopic instrument possesses multi-functional features by integrating grasping, dissection, cauterizing, and suction-irrigation within the same device. Our approach emphasizes the technological challenges are described. After the integration of forceps with suction-irrigation features, the obstacles in the manufacturing of small-sized complex components along with its mechanisms are explained to overcome these difficulties. Currently, the designed instruments overcome unnecessary removal of devices one after the other, which consumes a significant amount of time and effort in an operation theatre. Integrating ensured both processes can take place simultaneously or one after another, repeating multiple times as desired to reduce trauma in surgical interventions. Finally, the research aims to target robot-assisted surgery and pose possible challenges with their solutions.

Md. Abdul Raheem Junaidi, Harsha Sista, Y. V. Daseswara Rao, K. Ram Chandra Murthy

Improvement in Wear and Friction Properties of Heat-Treated Steel Using Micro-grooved Patterns

Surface wear is one of the leading causes of failures in sheet metal forming dies. Surface wear significantly affects productivity as well as the overall product cost. For forming dies, D2 steel is mostly used. D2 steel is High Carbon High Chromium Steel (HCHCr). In the present work, modern surface modification techniques are investigated to understand their effect on tribological properties such as wear and friction in order to minimize the surface wear failures. Hence Modern surface modification techniques selected are plasma ion nitriding, micro-grooving, and solid lubrication. Plasma ion nitriding is a heat treatment process and carried out in plasma chamber. Micro-grooving was carried out using laser surface texturing. Dimple, rhombus, concentric circular, asterisk, and cross grooves patterns were used for micro-grooving. 5 Samples of D2 steel were prepared using heat treatment (plasma ion nitriding) and micro-grooving (laser surface texturing). Wear and friction coefficient of samples of untreated and treated D2 steel were determined on pin-on-disc Tribometer. Tests were conducted at room temperature with alumina pin (99.99% pure) and D2 steel plate samples with Graphite as a Solid lubricant. The micro-grooves provide storage spaces for graphite, indirectly improves the life of lubricant. Hence micro-grooving and solid lubrication help for effective improvement in the tribological properties. The outcome of this research work is very promising and showed reduction in wear and friction coefficient up to 95% and 80%, respectively, when these modern surface modification techniques are used.

Nikhil More, S. S. Lakade

Force Optimization for an Active Suspension System in a Quarter Car Model Using MPC

Traditional suspension system has fixed damping properties and provides constant response to varying road types. On the contrary, active suspension uses a linear motor which can adjust its damping properties in real time to provide enhanced passenger comfort experience. In this study the transient response of two control strategies Linear Quadratic Regulator (LQR) and Model Predictive Control (MPC) have been compared for an active suspension system. A force optimization in active suspension has been illustrated by comparing the LQR and the MPC control schemes. Quadratic cost function for both the control schemes has been optimized for the state and input variables. Simulation is carried out using MATLAB-SIMULINK and effect of the variation of the weights has been studied. The reduction in actuator force usage when MPC is used has been reported.

Jayesh Narayan, Saman Asghari Gorji, Mehran Motamed Ektesabi

Mobility Analysis of Coupled System of Upper Limb Exoskeleton and Human Arm

Misalignment between human and exoskeleton joints is an inevitable challenge that hinders user’s safety, comfort, and assistance efficiency. It also results in undesired interaction forces that are applied to the human body limbs, further affecting the safety of the user. In this context of the design of exoskeletons and the study of misalignment effects—through mobility analysis, the overall motion of the coupled model of the exoskeleton and the human limb is proposed to be studied. This paper focuses on the mobility analysis of a coupled system of a 2-DOF (degrees-of-freedom) upper-limb exoskeleton for rehabilitation purposes of the human arm. In this work, planar rehabilitation exercises are used as tasks to be followed by the exoskeleton. These possess only planar motion, (i.e., parallel to sagittal plane) consisting of 2-DOF, i.e., flexion–extension movement of both shoulder and elbow joint. Two different configurations (type I and type II) of the upper limb exoskeleton are used to demonstrate the proposed methodology. The type II mechanism consists of redundant DOF that are used to address the problem of misalignment associated with the shoulder joint. The coupled systems of both types are further analyzed and compared in terms of their performance through screw algebra.

Macha Vidyaaranya, Sakshi Gupta, Ekta Singla

Pressure Vessels, Acoustics and Noise Control, Mechanical and Electro-Mechanical Systems of Modern Machinery


AHP Integrated TOPSIS Methodology for Selection of Non-Conventional Machining Process for Micro-Drilling

Selection of the most suitable machining process for micro-drilling is very crucial in precision machining. Manufacturing and dimensional errors can occur due to improper selection of machining methods. While making the decision for available processes for the best, ideology of the people may clash with each other. Analytical hierarchy process (AHP) is widely used for accessing the criteria weightage and prioritizing the decision-maker’s factors for the selection of best process. AHP has the ability to reconcile inconsistencies in the data. The technique for order of preference by the similarity of ideal solution (TOPSIS) is utilized for the final selection of micro-drilling process with calculated weightage from AHP. In the case study, AHP is considered for determining the criteria weights of each parameter. The parameters considered are hole-tolerances, operating voltage, depth, minimum diameter; surface roughness, and cost. For priority making performance rating values are organized in descending order. When machining processes are ranked according to their relative closeness to the ideal solution, the priority ranking is obtained as EDM>USM>EBM>LBM. suitable process for drilling hole of the smallest possible diameter and maximum possible depth is evaluated as EDM by AHP and TOPSIS methodologies.

Pranav Vijay Deosant, Ashish Ravindra Lande, Anurag Gopal Vishwakarma, Hemant P. Jawale

Design and Development of Acoustic Metamaterial and Micro-Perforated Panel by Using 3D Printing

Metamaterial designs can be modified from their structure, which provides the possibility for wave attenuation at different frequencies. The metamaterials and micro-perforated panels (MPP’s) are porous structures, therefore are lightweight and contribute toward improving the acoustical experience in applications like aircraft, road vehicles, etc., than the conventional materials.This study presents an experimental, and software-based study on sound absorption through various MPPs and MPP–porous structure combinations. MPPs and metamaterials/porous structures are modeled and additive manufacturing (FDM) is used to create them. The experimental study tests the different core structures and MPP–core structure combinations in the impedance tube to reveal that the honeycomb structure coupled with the MPP acts as Helmholtz resonators, which is extremely good for sound absorption in the low-mid-frequency range, followed by the octagonal and modified hexagonal structure.The simulation study carried out in COMSOL 5.5 evaluates the sound absorption capacity of MPPs, compares and investigates the effect of various dimensional parameters like hole diameter, plate thickness, and number of holes on the sound absorption coefficient that in turn measures the extent of sound absorption by the MPPs.

Atharva R. Kshirsagar, D. Job Sandeep Rajprian, J. Jeyanthi

Study of Effect of Angle of Contact and Angle of Extension of Wear Plate on Maximum Stress Induced in Horizontal Pressure Vessel

Horizontal Pressure Vessels are supported by two saddle supports near the ends. There is a local stress concentration in the vessel near the saddle horn of the saddle support. The parameters of a saddle support that can be changed are the angle of contact of the saddle, the width of saddle, the width of wear plate, and extension of the wear plate over the saddle horn. These parameters directly govern the values and location of maximum stress in the vessel. The aim of this study is to perform FEA analysis and find the effects of different configurations of the saddle and its effect on the maximum stress in the vessel and thus find the most optimum configuration of the saddle to pass the ASME requirements while keeping the material costs at the minimum.

Aniruddha Nayak, Pravin Singru

Effect of Number of Stiffening Rings, Their Position and Cross Section on Stress Concentration Near Saddle Support in Horizontal Pressure Vessels

Stiffening rings are very commonly used in horizontal pressure vessels where external pressure is applied to give protection against circumferential buckling but, also in the case of thin and long vessels, where internal pressure is applied, use of stiffening rings become very crucial to avoid stress concentrations at certain parts of the vessel and also give extra stiffness to the shell so that it can resist the load of the bending due to the dead weight and the fluid load. In this study, we performed FE analysis on different configurations of stiffening rings by varying the cross-sectional shapes, number and locations of stiffening rings and studied how the different configurations affect the maximum stress concentration in the pressure vessel. This study is important because knowing the right configuration of stiffening rings will lead to a more optimized way of using stiffening rings leading to savings in material cost.

Aniruddha Nayak, Pravin Singru

Water Wave Interaction with Very Large Floating Structures

This paper deals with the hydroelastic responses of very large floating structures(VLFS) connected with mooring lines at the edges of the VLFS. The structural deflection of the floating VLFS is analyzed for oblique incident waves. A coupled finite difference method (FDM)–boundary element method (BEM) is used to get a numerical solution of the associated physical problem. This study examines the deflection of the floating VLFS for a wide range of wave and structural parameters. It is seen that the mooring stiffness and incident wave angle play an essential role in reducing the VLFS deflection up to a great extent.

Kottala Panduranga, Santanu Koley

Annual-Averaged Performance of Oscillating Water Column Wave Energy Converter Devices in Real Sea Conditions

The present study investigates the annual-averaged plant efficiency of an OWC–WEC device under the random incident waves in local wave climate. The OWC–WEC is situated over a bottom foundation. To model the local wave climate around the OWC plant, the Bretschneider wave spectrum is taken as the incident wave spectrum. The related BVP is solved using the BEM. To analyze the efficiency of an OWC–WEC under the irregular waves, annual-averaged plant efficiency and free surface elevations outside and inside the OWC device chamber are studied in a detailed manner. Finally, the optimized combinations of chamber length and submergence depth, turbine rotor diameter, and rotational speed to enhance the efficiency of the OWC device is provided.

Kshma Trivedi, Santanu Koley

Material Handling and Automated Assembly


Inverse Kinematic Model of a Cable-Driven Continuum Manipulator

This article presents a geometrical procedure to obtain the inverse kinematic (IK) model of a planar multi-section cable-driven continuum manipulator (CDCM) in terms of its configuration parameters. Also, the actuator space (cable lengths) of the proposed continuum manipulator is portrayed in correlation with the motor angle rotation. The radius of curvature of the cables of the continuum manipulator is expressed geometrically in terms of backbone radius, cable lengths, and bending angle of the curve. The workspace of the manipulator is analyzed for the different bending angles of the continuum robot backbone, whose upper and lower motor angle limits are set based on the geometric parameters of the vertebra of the continuum manipulator. These limits restrict the extreme postures of curvature. Finally, the proposed IK approach is validated for the tip of the continuum manipulator to follow a semi-circular path.

Vipin Pachouri, Pushparaj Mani Pathak

Task Space Reconstruction in Modular Reconfigurable Manipulation System

Modularity and reconfigurability are efficient and effective solutions to achieve customization in manipulator designs. Customized configurations would be required to accomplish a set of non-repetitive tasks in various fixed environments. These customized manipulator designs are task-based; thus, automatic reconstruction of the task-space is required to create a virtual model for integrating the workspace in design algorithms for task-based customization and design studies. Secondly, it can be integrated with the developed customized robotic systems for demonstrating path planning. To achieve this functionality, we utilize a scene reconstruction framework based on RGB-D cameras for constructing a 3D model of the environment that captures all the necessary geometric and color information. In the first stage of scene reconstruction, various pre-processing activities like point cloud generation and timestamp matching are carried out. In the next stage of local registration, Random Sample Consensus (RANSAC) algorithm and local image features are used for estimating relative transformations between frames. Subsequently, global registration is carried out to find the absolute transformations with respect to a global frame. A scalable and efficient voxel-based representation is used for representing the model. A Robotic Operating System (ROS)-based platform is developed for the complete demonstration of the work in which modular configurations and task-spaces are visualized using Rviz and the path planning of the modular configurations considering the goal positions are done using Moveit! all within the ROS framework. Implementation of the methodology is illustrated through an example of a case study of the utilization of modular manipulators in different work cells.

Athul Thaliyachira Reji, Anubhav Dogra, Shashi Shekhar Jha, Ekta Singla

Design Analysis and Experimental Validation of Modular Handling System for Satellite Ground Application

Assembly Integration and Testing (AIT) of spacecraft involves a large number of handling operations which are carried out with the help of spacecraft handling system, it is one of the major hardware in Mechanical Ground Support Equipments (MGSEs). The conventional type of handling system consists of mild steel beam section and required many operations like drilling and welding for final hardware realization. Over the conventional handling system, a novel Modular Handling System (MHS) using aluminum extruded complex cross-section profiles with high strength-to-weight ratio is presented. The 1D beam FEA of these profiles gives only approximate results like maximum stress and deformations, so to analyze the assemblies for detailed stress distribution we need to adapt 3D/2D meshing but 3D meshing is complex for these cross sections and requires more solver time. Therefore, an approximation approach is adopted by using 2D shell element meshing over 1D element by maintaining moment of inertia to that of original profile of each cross section, and validated under the cantilever beam with point load condition of FEA results and compared with the analytical calculations. With confidence of these results the present work aimed to analyze MHS by using 2D mesh and perform linear static FEA to determine stresses and deflection.Further, MHS hardware is fabricated, assembled, and realized for experimental validation using strain gages with static loading test facility, and results are compared with finite element simulation results and found close match. The experimental validated MHS hardware successfully utilized for lifting the spacecraft’s sub-assembly/assembly during AIT activity.

G. A. Srinivasa, Shashank Srivastava, Saurabh Chandraker

Numerical Investigation on Dynamic Stability of a Pick and Place Robot Arm

The flexural behaviour of robotic manipulators provides certain advantages such as high payload-to-weight ratio and speedy movement. Flexural nature of such robot arms consumes relatively lower energy as well. However, this design of robotic arms spurs vibratory actions, which in turn penalizes the work of robotic arms. Knowing and atoning for the tendencies of such robots to vibrate is therefore of great consequence, especially for a pick and place robot arm used in material handling is to be performed with high level of accuracy.In the present work, an attempt is made to predict the dynamic behaviour of a flexible robot arm by considering most of the possible nonlinear attributes, which makes the analysis more realistic. Robot arm holding mass is modelled as a beam with a tip mass at the free end, and the other end is connected to a support which enables a rotary motion of the robot arm. The flap-wise vibration behaviour is investigated using the energy-based approach. Nonlinear equation of motion with appropriate boundary conditions is derived using extended Hamilton's principle and subsequently solved using a perturbation method, namely, method of multiple scales. The results indicate that the ratio of linear-to-nonlinear frequency of the system is found to decrease with the increase in tip mass. On the other hand, these ratios are increased by an increase in the rotating speed of the hub.

B. Upendra, B. Panigrahi, K. Singh, G. R. Sabareesh

A Method for Evaluation of Welding Performance of SMAW Electrodes

The Shielded Metal Arc Welding (SMAW) is used extensively in different industry segments for different applications, e.g. structural welding, general welding fabrication, etc. Stick electrode is one of the major components of SMAW process. However, end users extensively using these electrodes have reported variable weld penetration and unwanted spattering recurrently during the SMAW process. Concerns have been raised about weld spatter defined as loss of electrode material. Excessive spatter results in productivity loss as unscheduled work stoppage happens due to weld cleanup, repair and rework requirements. Extent of spatter is a major quality issue and a product differentiator. After an elaborate exercise, negligible differences were observed among the electrodes in terms of welding performance issues, e.g. spatter, weld bead profile. Spatter measurement results show that Electrode A produced fewer spatters than Electrodes B and C at almost all current levels. All-weld chemical composition and all-weld tensile properties were also found to be similar for all three electrodes as electrodes were hailed from the same category.

Brajesh Asati, Ravi Shanker Vidyarthy

Modeling and Kinematic Analysis of a Robotic Manipulator for Street Cleaning Applications Using Screw Theory

In this article, a robotic manipulator for performing street cleaning operation is proposed. Kinematic analysis is performed for the proposed robotic manipulator using screw theory. Forward kinematics of the manipulator is executed utilizing the product of exponential (POE) formulations and the inverse kinematics is performed using Paden–Kahan (PK) sub-problems. The implementation of these sub-problems leads to provide multiple solutions and a geometric view to the inverse kinematic analysis. Joint angles for a desired trajectory of the end effector are taken from @SolidWorks. These angles are fed to the forward kinematic algorithm that gives a series of homogeneous transformation matrices (HTM). This HTM is taken as input in the PK inverse kinematics algorithm. Algorithms for the forward and inverse kinematic analysis are executed using MATLAB. The joint angle solutions obtained using PK sub-problems for the series of desired configurations are compared with the conventional numerical inverse kinematics technique, to know the computational efficiency of the solutions obtained. The solutions obtained from the considered algorithms are implemented on a virtual robot created in V-REP robotic simulation environment. The solutions obtained with the above approach play a vital role in robot control, design, and path planning.

Neel Gandhi, Garlapati Nagababu, Janardhan Vistapalli

Hybrid Electric Vechicle and Electric Vechicle Mechanisms


Dynamics and Isolation Capabilities of a Magnetic Spring-Based Quasi-Zero Stiffness Vibration Isolation Mechanism for Passenger Vehicle Seat Isolation

In this work, the dynamics and vibration isolation capability of a quazi-zero stiffness (QZS) vibration isolation system based on a magnetic spring is investigated with an emphasis on its application to isolate passenger seat in a vehicle. The inclusion of magnetic springs avoid the chance of contact between the parts and therefore the influence of friction and contact nonlinearities is negligible. The nonlinear force–displacement relationship for the magnetic spring system is obtained by performing numerical simulations in FEM magnetics. The influence of the geometric parameters on the QZS characteristics is investigated to select a suitable combination for different masses to be isolated. The concept of QZS isolation is implemented in a passenger seat isolation system by replacing the conventional linear isolator. Human body is modeled as a multi-degree-of-freedom system and the transmissibility plots are obtained to study the isolation at different parts of the human body. The results are compared with that for a linear isolator. It is found that proposed QZS isolator based on magnetic springs is effective in isolating low-frequency vibrations.

Prajapati Brijeshkumar, B. Santhosh

Vertical Vibrations of the Vehicle Excited by Ride Test

A mechanical equivalent model has been developed to characterize the response of the vehicle excited by road profiles. The mechanical equivalent model offers an estimation of accelerations of vehicle along vertical axis in terms of natural frequencies and dissipative properties of vehicle. The mathematical model considers the differential equations governing the forced vibrations of the MIMO system model (order 4, with two inputs and two outputs) of suspension system. The response of suspension system is evaluated by convolution integral solution for system with general damping. In order to calibrate the mathematical model, an experimental design is developed by the ride test. This test provokes the impact between a vehicle and a rectangular-shaped cleat bar on a road. The least square error evaluates the good agreement between accelerations obtained by mathematical model and ones deduced by experimental investigations.

Massimo Cavacece, Giorgio Figliolini, Chiara Lanni

Investigation of Dynamic Forces and Moments in the Neck Region of the Driver of a Vehicle

High internal forces in the human body may have adverse effects on internal organs and may cause muscle fatigue. The neck region forces are of special concern since they are related to headache and motion sickness. It is difficult to determine these internal forces and moments experimentally. This work attempts to predict neck region forces and moments through a 12 degree-of-freedom (DoF) human body model. This has been integrated with a nonlinear cushion model, an inclined multi-compression damper-based seat suspension model and a 7 DoF full car model. The integrated system is analysed using MATLAB-SIMULINK for random and bump road profiles. With the increase in road roughness, the moments and forces in the neck region tend to rise continuously. With an increase in cushion damping, the neck region parameters tend to be lower. A cushion with a higher value of damping dissipates a larger amount of vibrational energy leading to improved human comfort. Cushion damping has a higher effect on the neck region in rough roads. With an increase in vehicle speed, neck region rotational moment and forces rise continuously, leading to deterioration in human comfort.

Raj Desai, Anirban Guha, P. Seshu

Analysis of Design of Head Restraints of Car Seat Considering Indian Anthropometry

Car seat design has gained extensive importance considering comfort and safety where it interacts with the human anthropometry. In the majority of car accidents, it is the car seat design and the design of the associated safety accessories that prevent damage to the driver’s body. Head restraint saves the passenger from Whiplash injuries due to sudden impact that may be fatal. Head restraint’s primary function is to support the head and keep the head in position with the torso in case of sudden impacts. In this paper, the importance of head restraint is justified by applying dynamic analysis to the head and torso model developed by solid modeling software considering the anthropometry of the Indian population. Anthropometry is crucial for design consideration so that the design conforms near to the ideal design which would accommodate the majority of the populace. The head restraint that is not designed considering anthropometry would leave many individuals at a disadvantage of safety issues that a car design promises. Ergonomics of the head restraint is important to arrest the undesired head movement. This paper presents the analysis of the current commonly used car seat’s head restraint design in various ratings of good, acceptable, marginal, and poor according to Indian anthropometry.

Radhika Tekade, Girish Ramteke, P. V. Kane

Novel Method for BSR Test Cycle Generation

Buzz Squeak and Rattle (BSR) problems in body structure and trimmed parts are always a critical problem for automotive OEMs, due to their influence on the initial quality perceptions of customers. Generally, the find and fix approach is used and it has become necessary to find BSR problems in the initial stage of vehicle development as there has been a significant increase in reducing the development time of the vehicle. The general procedure followed by an industry is to test the complete vehicle or its sub systems in a test rig. Panel gaps, worn-out parts, and improper assembly are the major sources for BSR problems. A vehicle with necessary instruments was driven thousands of kilometers to capture the test cycles. This process consumes a lot of time, manpower, and money. In this work, a technique is proposed to reduce the test cycle generation time. A typical test cycle consists of important load characteristics which are experienced by the vehicle when driven from one place to other. The test cycle was generated by combining the major influencing parameters of the special features of a road. The special features are road humps, path holes, patchworks, etc. Typical parameters which represent these features uniquely were identified from the vibration signals captured in the road test. These parameters were combined and placed in an order, and the typical test cycle was generated. The algorithm was designed such that any road load can be generated if the features representing the road are known, thereby avoiding the expensive instrumentation required.

K. J. Sarat, C. Lakshmikanthan

Feasibility of Adoption of Double-Crank Inversion of Four-Bar Chain as a Substitute for a Gear Box

In this paper, a complete investigation with respect to the kinematic properties of double-crank inversion of a four-bar chain is presented. The observation from preliminary analysis of the coupler of the double-crank inversion shows that all points in the coupler plane trace a circular path with variable angular velocity. It is verified through graphical kinematic analysis, i.e., drawing mechanism configurations for its different positions in one cycle of operation of the mechanism that for a four-bar chain O1ABO2, where O1O2 = 15 cm (fixed link), O1A = 40 cm (input driving crank), AB = 35 cm (coupler), and BO2 = 50 cm (output crank), each point on the coupler plane has a specific band of variation of angular velocity and the points lying at a radius of 5 cm–8 cm from point A have its angular velocity variation band up to 8–12%. There are possibilities of tapping motion from various points on the coupler plane to get output shaft speed variation over a certain band.The above fact motivates the investigator to explore the complete range of such mechanisms. The outcome of this exploration may reveal a new design of gear box in which several output speeds could be available with a very low band of variation of angular velocity. There are many process units, for example, low capacity crusher, chopper, cutter, mixer, plastic shredders, etc., for which such a transmission can be used instead of gear box. The most important shortcoming of a presently available gear box that is manufacturing synchromesh and/or the gear itself can be overcome by adopting double-crank inversion.

Akshay Anant Pachpor, Jayant Pandurang Modak, Prashant Brajmohan Maheshwary

Structural Synthesis and Classification of Epicyclic Gear Trains: An Acyclic Graph-Based Approach

Graph theory-based representation is commonly used for modeling the kinematic structure of mechanisms thereby facilitating the listing of all feasible mechanisms that meet certain design requirements. The structural synthesis of kinematic structures is then carried out, using graph algorithms. For the case of epicyclic gear trains (EGTs), the overall synthesis involves the successive steps including the enumeration of rotation graphs and then deriving displacement graphs with respect to each rotation graph. The first step (listing of rotation graphs) is crucial and it is generally algorithmically involved than the other step, namely, generation of displacement graphs. Many scientific works have employed the conventional non-recursive scheme, for enumerating the rotation graphs. However, in this work, a new non-recursive method is proposed. This newly proposed scheme uses acyclic graphs of a certain number of vertices as parents for enumerating rotation graphs of EGTs (whose number of links same as number of vertices of the acyclic graph) of any number of DOF. This method can be easily automated using a computer program. It is applied in the synthesis of EGTs with and up to 7 links and the results are verified with that of the literature.

V. R. Shanmukhasundaram, Y. V. D. Rao, S. P. Regalla, D. Varadaraju, E. Pennestrì

Fuel Economy and Drivability Trade-Off for Mild Hybrid Electric Vehicle Architectures

Modular hybridization of conventional powertrains, i.e., adding electric machines and batteries to an existing conventional powertrain, has been proposed as a cost-effective method of fuel economy improvement, when compared to designing a dedicated hybrid powertrain from the ground up. “Mild” hybridization, where the electric machine/battery power is a small fraction of the engine power, is especially appealing due to its ease of packaging, and higher ratio of fuel economy benefits to cost. Based on the location of the motor on the driveline, relative to the engine and transmission, certain mild hybrid architectures are commonly seen in the market today. These include the P0, P1, and P2 architectures. The choice of each of these architectures is a trade-off between cost, ease of packaging, drivability, and fuel economy gains. This paper discusses the fuel economy and drivability trade-off for each of the above architectures. Typical power limits for the motor and the battery, based on the architecture, are stated. Based on the power limits, the associated possible fuel economy gains with each architecture are reviewed. Using simulation data, it is shown that the P2 architecture offers the potential for the largest fuel economy gains, among the three. Results from the study of the trade-off between fuel economy and drive quality for this architecture are also presented.

Neeraj Shidore, Norman Bucknor, Madhusudan Raghavan
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