Machines, Mechanism and Robotics

Iron-based calorimeter is used for the study of Neutrino consisting of huge electromagnet and a large number of RPC detectors in India-based Neutrino Observatory (INO) project. RPC detectors are handled by a customized rail-mounted-movable RPC-handling trolleys. In this paper, the problem of static stability of trolley support structure has been discussed. Lift support structure of RPC handling trolley is modeled and analyzed considering trolley self-weight and weight of platform including payload. Using FEM solver, the critical buckling load is estimated and found within a safe limit. Results obtained from FEM analysis are also practically validated on a scaled down fabricated model of lift support structure of RPC trolley subjected to an equivalent load. This study is beneficial for optimum material use for working forces and for the safety of working staff.

The problem of identifying free space in an environment from a given single image is a subject matter of interest in the field of computer vision and robotics. The aim of this paper is to construct a scaled 2D floor map from a single two-point perspective (2PP) image for visualizing the relative dimensions and poses of the objects, by taking minimal information. This is done by proposing a new simple method which utilizes the perspective property of the given image, viz., vanishing points. This paper introduces necessary geometrical constructions by introducing the notion of the side view of an image, using which few simple geometrical relations will be derived, that will help in constructing a 2D floor map. To the best of our knowledge, this is the first work of its kind, which introduces architectural concepts for map construction and for measurements from it, thus proving novelty of the introduced method.

The purpose of the paper is to formulate the optimum robotic surgical framework to perform a high-precision neurosurgery. The DICOM data tags are meticulously identified and used to build the optimum robotic surgical framework to develop accurate neuro-registration and neuronavigation. Algorithm along with GUI is developed for neuro-registration and neuronavigation. The different Unique Identifiers (UIDs) of DICOM are studied and all the slices of the various views are classified and stored as a data series file. From a single DICOM series, the three orthographic views, an oblique view of choice and a 3D model of the patient’s brain are reconstructed and displayed. The DICOM data information of patient posture is extended to develop optimum robotic surgical framework to perform a high-precision neurosurgery. Surgical Coordinate Measuring Mechanism (SCMM)-based neuro-registration and neuronavigation are demonstrated on the various phantoms and a real human skull to validate the data preparation for neuronavigation. The test procedures are found to be in accordance with the neurosurgical standards. A neurosurgical procedure is demonstrated by utilizing workspace of the surgical robot. The SCMM-based neuro-registration procedure eliminates the ‘line of sight’ constraint as in camera-based neuro-registration procedures. The utility of optimum workspace strategy of the robot helps in bringing highest manipulability at the required region.

Gearbox is commonly used in many manufacturing and engineering applications. An accurate condition monitoring and health assessment is necessary and important to detect faults in gearbox to monitor machinery performance and avoid machine breakdown. This paper aims to demonstrate an approach for the condition monitoring of gearbox to recognize the fault at an initial stage by applying control chart as a tool by analyzing the acceleration-time domain signals. In this paper, time series model is used to extract the features characterizing faults and the exponentially weighted moving average control (EWMA) charts are obtained to monitor the deviations in the feature values. The variation of these features is monitored using EWMA control charts. The gear fault can be simulated in gearbox by different techniques. The most commonly observed fault in the gearbox is gear tooth failure due to scoring, wear, pitting and tooth fracture and it can be simulated by partial tooth removal during the experiment. In this study experiment, the fault with increasing severity is simulated on the spur gear tooth by filing operation. Experimental data for healthy gear and gear with three stages gear tooth removal, i.e. 37.5, 75 and 100% is acquired. EWMA charts were plotted using the data collected for the above severity of faults and it is observed that the control chart is an effective tool in identifying the deviation from the normal condition.

The objective of this paper is to generate a unique and robust correspondence between two sets of points, one from the image frame of reference and the other from a set of points in the surgical tool frame of reference; irrespective of the alterations in the number of points or in the sequence of measurement of the points in the image or the tool frame. The radio-opaque markers (affixed to the scalp of the patient before MRI/CT Scan) serve as a reference in neuro-images. The coordinates of the markers on the patient’s scalp with respect to the robot (surgical tool) frame are measured during neurosurgery. From the data, the relationship between the anatomical frame and the tool frame is established. Distance and uniqueness criteria between the markers are used to determine the correspondence. Validation is obtained by conducting correspondence on the phantoms with various configurations of marker points.

Gas foil bearings (GFBs) has been considered as an alternative to traditional bearings in turbopumps, turbocompressors, and turbochargers. The popularity of this bearing has motivated the researchers and people from industries to explore its capabilities. In this context, a nonlinear transient analysis of a rigid rotor supported on airfoil bearing under unidirectional constant load and unidirectional periodic load is carried out. The nondimensional form of the Reynolds equation is discretized using Finite Difference Method while the Crank–Nicolson method and Newton–Raphson method are used to obtain the pressure at every time step. Mass parameter, which is a function of the speed of the rotor, has been considered as the parameter of stability. It has been observed that a rotor stable under unidirectional constant load can be unstable under unidirectional periodic load.

Identifying and generating the Regions Of Interest (ROIs) in a set of images is an important step towards planning treatment in neurosurgery. Existing Neuronavigation software require manual marking of a specific ROI in consecutive slices of the DICOM images to generate the solid model of a ROI. The volumetric shape and position of the ROI serves as a reference to the surgical tool during neuronavigation. The paper presents an algorithm for the semiautonomous generation of ROI from the slices of images using a single click. This paper is aimed at isolating the ROI in a CT/MRI scan, along with eliminating all non-ROI regions. This reconstruction in 3D along with the real-time 3D superposition of the surgical tool provides for a highly focused visualization of the surgical problem, along with significantly improved rendering performance.

A comparative analysis between a hybrid and a parallel manipulator, to study the influence of their architecture on performance, is presented in this paper. The two manipulators are modifications of a serial 2-R manipulator and a five-bar manipulator, respectively. They are altered in a way that they both share the same arrangement of the links, while having a distinction only in the actuator arrangement. Indices of performance, such as the measure of manipulability, local conditioning index, and global conditioning index are used to compare their performance.

This paper presents a comparative study between two related methods of formulating the equations of motion, within the Lagrangian framework, for closed-loop mechanisms. Such mechanisms encounter singularities not only at the boundaries of their workspaces, but also inside the workspaces. The latter kind of singularities are detrimental to the operation of the mechanisms and may lead to their mechanical failure. The primary objective of the paper is to investigate the ways in which these singularities impact the two formulations, and to establish a relation between them. A planar five-bar mechanism is used to illustrate that the singularities appearing in one formulation is a subset of those appearing in the other formulation. The second objective is to provide a qualitative analysis of the time-complexities of the respective formulations. A planar five-bar and the Stewart platform manipulator are used to study and compare the computational costs incurred in either of the formulations.

The paper presents the synthesis of Stationary-Active (St-Ac) axes mechanisms starting from two DOF to six DOF parallel manipulators. The St-Ac type of parallel mechanisms show certain advantages over the moving axes or pivoted axes type of actuators. Due to the Stationary Actuator feature, certain design features are possible, which are not feasible in case of the pivoted axis or moving active axes type of parallel mechanisms. The paper shows the overriding characteristics of St-Ac axes configuration that will influence its choice in certain applications. The mechanical master–slave manipulator design, common shaft control of St-Ac Parallel Manipulators and the prototype of St-Ac has been demonstrated.

This paper presents a direct formulation of dynamical equations for a space robot actuated by control moment gyros (CMGs). The space robot consists of a service satellite and a robotic manipulator comprising an arbitrary number of rigid links connected by spherical joints. A cluster of CMGs is mounted on the base and on each link. The static and dynamic imbalances of the gimbals and the rotors are both considered. Dynamical equations for the robotic system level are derived using Kane’s equations. The nominal output torques of the CMGs and the disturbance torques caused by the imbalances are separated, with each having explicit expressions. A feedback controller based on the nominal model is also proposed for system trajectory tracking control. Simulation comparisons based on different imbalance parameters show that the controller works, but the imbalances may cause both high-frequency and low-frequency disturbance torques, which may distinctly decrease system-control accuracy.

A two-degree-of-freedom RSSR-SSR manipulator is proposed for the sun-tracking application. A detailed study of its forward and inverse kinematic problems is presented. It is illustrated through an example that the requisite range of motion can be achieved for exact tracking at the chosen location without encountering singularities or violating the limits of commercially available spherical joints. Static analysis is also performed to show that the load is significantly distributed among the two limbs, thereby reducing the strength requirement on the foundations at base pivots.

For repetitive material-handling operations in various industries, fixed automation using single-degree-of-freedom mechanisms can often serve as a low-cost alternative to multi-degrees-of-freedom robots. Therefore, developing design procedures for inexpensive fixed automation solutions may be highly relevant in the context of developing as well as underdeveloped economies. A design methodology to analytically synthesise a planar pick-and-place system for displacement and velocity requirements using a planar four-bar mechanism is carried out in this work. A methodology to establish the availability of kinematic defect-free solutions in terms of two free design parameters is also proposed and illustrated with a numerical example.

In this paper, the forward kinematics of the $$3$$-RPRS manipulator is posed as an intersection problem of two plane algebraic curves. The manipulator is hypothetically decomposed into two kinematic sub-chains by dismantling one of the spherical joints. A pair of points, consisting of one each from the said sub-chains, are now constrained to individual loci, the points of intersection of which lead to the assembly modes of the manipulator. Computations of these points lead to the derivation of a 16-degree univariate polynomial equation, whose coefficients have been obtained as closed-form functions of the architecture parameters and the actuator variables. It is also found that this polynomial has only the even-powered terms, making it effectively an octic equation. The theoretical results are illustrated with the help of a numerical example and the results are validated numerically.

Shake Tables are used to simulate the effects of earthquake loading on specimen structures and conduct experimental research in the areas of vibration, structural testing and safety assessment. In India, most high-capacity Shake Table installations are imported. Refuelling Technology Division, Reactor Design and Development Group, BARC has indigenously developed a 500 kg payload six-DOF Shake Table and commissioned at BARC. Synchronous control of all the eight actuators of the Table is required to control the Shake Table. Each actuator is provided with position, acceleration, differential pressure and load feedback sensors. A total of 40 feedback sensors are used in the Shake Table control algorithm with a control loop update rate of 1 kHz. It is required to acquire various parameters during Table control in order to do offline analysis and also to use in control strategies like experimental system identification and iterative tuning. The design and development of electronic control system for six-DOF Shake Table also includes implementation of various control methods such as Degrees of freedom (DOF) control, force balance control, and three-variable control (TVC) on a suitable electronic system. No generic hardware and software that satisfies all the control requirement of the Shake Table is readily available. Design and Development of an electronic control system that satisfies all the control requirements of the Shake Table is described in this paper. This development is based on four numbers of indigenously developed Double Actuator Controller with Dual CAN bus Interface (DACCI) networked through CAN bus. This paper describes Control and Instrumentation architecture, specifications and performance of the indigenously developed control system of the Shake Table.

Omnidirectional welding mobile robot (Omni-WMR) consists of a manipulator mounted on the mobile platform equipped with omnidirectional wheel. Omnidirectional mobile robots have the capability to move in any direction and hence it is finding a prominent place in many applications in manufacturing and processing industries. This capability avoids the transportation of heavy and lengthy material to the workspace. As the manipulator mounted on the mobile platform while performing the task, it is necessary to study the effect of platform motion on the dynamic behavior of manipulator and vice versa. This paper is focused on the dynamic interaction between manipulator and platform. For this, coupled dynamic model of Omni-WMR is developed. To evaluate this approach, two different case studies are presented in this paper. Results show that there is a significant change in torque values developed at manipulator joints due to the platform motion and vice versa as well as change in position of the manipulator.

Articulated landing gears have relatively lower stowage volume and provide better taxiing characteristics when compared to telescopic gears. Unlike telescopic configuration, the articulated configurations do not have the same stroke for wheel axle and shock absorber travel. The objective of this work is to study and compare the dynamics of the articulated main landing gear, during level and tail-down landing conditions, using MSC/ADAMS software. The results are compared with the available landing gear analysis program, which has been experimentally validated by the drop tests. A 12.3% reduction in total vertical wheel axle travel is observed in tail-down condition when compared to level landing, due to the kinematic configuration. It results in 18.9% and 14.8% increase in dynamic load in limit and reserve landing respectively for tail-down condition. Also, the tire deflections are relatively higher and the shock absorber travel is relatively lower, in tail-down landing for both limit and reserve conditions.

A pair of identical unbalanced rotors, independently driven by two separate DC motors, is placed on a common movable platform. The assembly is designed as an SDOF spring-mass-damper system and the modeling is done entirely on MSC Adams. For a set of predefined system parameters, the voltage values for both motors are operated manually and separately. Both motors are defined as nonideal drives with inadequate power supply. With the help of simulated responses, the Sommerfeld effect along with the phenomenon of self-synchronization is studied numerically, with an aim to attenuate large amplitude vibrations for the movable platform.

The paper deals with the design and implementation of a high-precision six DOF parallel mechanism based system for mirror alignment inside a high vacuum chamber. Analysis and synthesis are carried out in order to meet the desired range of mirror mobility in six dimensions in the presence of cylindrical constraints due to the two-column support of the mirror. The beam alignment system should have a translation resolution of 1 µm and rotational resolution of 1 arc-sec about a remote mirror coordinate axis. This paper discusses in detail the design and development of a Mirror Positioning Mechanism System (MPMS) meeting the above requirements.

A portable Surgical Coordinate Measuring Mechanism (SCMM) is designed and developed to measure the 3D coordinates of a point and a line vector passing through a point in its workspace. The synthesis of the mechanism is done to localize a neuro-anatomical reference frame with respect to the robot reference coordinate system. The SCMM is an articulated serial chain and is an important constituent of the neurosurgical suite being developed by DRHR, BARC, Mumbai. Dimensional synthesis of the SCMM is carried out by optimizing the mechanism footprint and manipulability of the neuro-registration. Design, development, calibration, and demonstration of SCMM are discussed in the paper. The paper emphasizes that the measured values of the D-H parameters are most often not practically feasible for implementation. It is shown that calibration-based methods are useful for improving the accuracy of system.

In-service inspection requirements of reactor internals of sodium-cooled fast reactors offer challenges in the design and successful deployment of carrier mechanisms. A single-carrier mechanism consisting of inter-connected rigid links having multiple ultrasonic transducers is envisaged for carrying out all the necessary inspections. The kinematic analysis of the chain assembly of the proposed carrier mechanism is the main focus of the present paper. Initially, a base design of the chain assembly was proposed and the same is analysed with respect to the linearity and smooth motion transmission. The kinematic chain of the base design was modified to improve the motion transmission characteristics. Parametric studies were done to fine-tune the design parameters of modified design. The analysis has given valuable insights into the performance of chain assembly and provided necessary data for the smooth operation of chain assembly.

In practical operation of mechanisms, joint clearances and compliance influence the overall performance drastically. Excessive clearances induce extra degrees of freedom at the joint, while compliance provides an additional torque. This paper presents the dynamic analysis of partially compliant planar slider–crank mechanism with joint clearance. When joint clearance is considered, an additional intermittent impact force acts on the system and velocity and acceleration as well as forces at the joints change drastically. Therefore, mechanisms are often made compliant with limited number of joints. In order to model compliant linkage, equivalent torque is introduced at the joint using pseudo-rigid-body modeling. Initially, the turning moment and force equations of crank, coupler, and slider are obtained in terms of contact forces at the clearance joint. Effect of clearance at the crank pin on the kinematic and dynamic characteristics is studied in detail.

A McKibben actuator/Pneumatic Artificial Muscle (PAM) is a soft actuator which has great potential in the field of bioinspired robotics. Miniaturized versions of PAMs or MPAMs of less than 1.5 mm diameter are ideal actuators for developing surgical devices due to their compliance and high power-to-weight ratio. Accurate mathematical model to represent the mechanics of PAM is an ongoing research. This paper develops a mathematical model which relates the input pressure to end-point deformation of a fabricated MPAM without external loading. The developed theoretical model is validated against experimental data for MPAM of lengths 60 and 70 mm. The model predicts the deformation of MPAM with standard error of less than 10%. The model is also able to predict the locking angle of $$54.7^\circ $$ at higher pressures which is a distinct characteristic of McKibben actuators.

Wrench guided task space trajectory motion control is described in the paper. Serving the change in task space trajectory frequently through code is insurmountable. An easily induced wrench trajectory at the task space as the input to generate proportional six DOF motion output is looked into as an alternative to conventional motion programming. The paper also discusses the implementation of joint force-based homing, task space force–torque estimation, and force-assistive task space motion. Each of the modules has been implemented on six DOF parallel mechanism-based manipulator.

This paper proposes a novel heuristic for searching a set of surfaces eligible for providing form-closure grasp of robotic fingers on a rigid polyhedral 3-D object. The key idea that drives the search of eligible surfaces is the formal definition of a convex hull which describes convex hull of a set of points as the smallest convex polygon containing all the points of that set. Eligibility determination of a set of surfaces is carried out by the test based on ray-shooting algorithm (Liu IEEE Trans Robot Automat 15(1):163–173, 1999, [1]), which is formalization of the necessary and sufficient condition for form-closure grasps requiring that the origin of the wrench space lies inside the convex hull of the primitive contact wrenches (Algorithm Spec Issue Robot 2(4):541–558, 1987, [2]). The implementation of three numerical examples demonstrates the usefulness and efficiency of the proposed heuristic.

In this paper, we describe a LIDAR-based autonomous navigation approach applied at tracked mobile robot and a software tool developed for managing the mobile robots’ outdoor radiation survey missions. A mission to do radiological survey around the scrap yard of lab premises has been considered as a concrete instance to build the system. Mission management tool is designed to plan autonomous radiation survey missions in affected areas. The robot carries radiation sensor packs suitable for the survey to record and transmit radiological measurements to the control centre. Additionally, the scheme implemented has provision to monitor the real-time progress of the survey mission and to switch between various autonomy levels built into the system.

Multi-fingered hands enable significantly enhanced manipulation capabilities to the robot where it is attached. As a consequence, analysis, design and development of multi-fingered hands has been of continuing interest in the robotics community. In this work, we propose a probabilistic Monte Carlo based approach to obtain the workspace of a well-known multi-fingered hand, the three-fingered Salisbury hand, modeled as a hybrid parallel manipulator. It is shown that Monte Carlo method can be used to obtain the volume of the well conditioned workspace of the hybrid manipulator in $$\mathfrak {R}^3$$ and SO(3). One of the obtained novel results is that with realistic constraints on the motion of the joints, the well-conditioned workspace of the hybrid manipulator is the largest when the grasped object area is approximately equal to the palm area. We also obtain and discuss the dependence of the workspace of the manipulator on it’s geometry and other link and joint variables.

The paper describes the design of mission planning and control architecture for an autonomous material handling system which perceives the live requirements of material movement on a factory floor and does judicious deployment of autonomous guided vehicles (AGVs) to service them. The system has a novel methodology to perceive prevailing situation on factory floor in terms of material transportation and fetching suitable mission, from a predefined set, for execution. This research effort is part of a long-term project that aims to enable AGV to carry out loading and delivery missions in hazardous areas of fuel fabrication facility, in a completely autonomous mode. The system is being used as an advanced test bed to test developments in mission planning and real-time mission execution system for AGVs. The system consists of single or multiple AGVs transporting material between several loading and delivery points, through a structured environment. It modularizes all aspects of factory automation like floor configuration, individual vehicle control, mission execution, high-level mission planning, and coordination. We present a methodology of building complex missions in terms of unique operations. In the later part, we present a case study based on a real scenario for evaluating the performance of indigenously developed AGV in simulation.

Advanced Heavy Water Reactor (AHWR) is a thorium-based vertical, pressure tube type reactor. The reactor needs to be refuelled periodically mainly to maintain requisite reactivity in reactor. A dedicated, remotely operated on-power Fuelling Machine (FM) is used for this purpose. The FM removes spent fuel from reactor, replaces it with new fuel and finally transfers the spent fuel to fuel transfer system of reactor. During refuelling, the FM interacts with high temperature and high-pressure coolant channel and maintains the pressure boundary during refuelling. The FM consists of various innovative design features like limiting load on coolant channel during refuelling, maintaining isolation between V1 and V2 volumes, handling of long fuel assembly, maintaining cooling and shielding of fuel, compact configuration, etc. Safe handling of fuel is ensured by incorporating adequate safety features to avoid fall of fuel during handling. This paper covers the design requirements, challenges and features of AHWR FM.

Naturally evolved fish fins display superior qualities over conventional man-made thrusters by offering better maneuverability, less or no noise, and better efficiency. Caudal fin of a fish contributes most of the thrust force in fish swimming through body and fin undulations. Fish fins naturally happen to be flexible. The present work investigates the effect of whole-body flexibility of caudal fin on thrust production. A flexible trapezoidal fin is modeled as series of rigid segments connected with torsion springs and the governing equations of motion are obtained through multi-body dynamics approach. The hydrodynamic force acting on the fin segments is calculated as summation of drag and added mass force components. Simulations are carried out with different stiffness profiles for different motion parameters. The results show that flexible fins perform better than the rigid fin and different motion parameters require different stiffness profiles for higher thrust production and better efficiency.

Mechanized forces of armies world over tend to use multi-axle vehicles for their versatile capability of deployment on-road and off-road operations. Manoeuverability on-road requires good high-speed control defined by handling characteristics and manoeuverability off-road required ability to overcome hairpin bends; this requires smaller turning circle radius. Studies pertaining to the selection of appropriate steering strategy are very limited. One of the approaches is utilizing a bicycle model of the vehicle. Bicycle model assumes the same magnitude for angle of left and right wheels; this holds good for large turning radii. Further to this, all steering strategies are evolved and those apt for practical implementation are considered in study. A worldwide survey of vehicles of similar class was also carried out. Four strategies were found after this exercise: first axle steer, first two-axle steer, first and last axle steer and all axle steer. An combined nonlinear ride and handling model developed using Simulink is used for carrying out the study. Physical parameters considered are lateral acceleration, yaw angle and vehicle side slip angle. If forward speed of the vehicle is assumed constant, higher magnitudes of lateral acceleration and yaw angle indicate vehicle ability to take a sharp turn or in other words better manoeuverability. Side slip angle is the difference between vehicle axis and the wheel axis. Vehicle designers strive to achieve near zero side slip angle. Apart from steering, other inputs considered are drive torque and road undulations. Longitudinal vehicle dynamics is of little consequence to this study and hence, equal and constant drive torque to all wheels is applied. Road undulations are provided as an input to the model from smoothened power spectral density (PSD) hyperbolic curve. The road undulation is defined by ‘C’ and ‘N’ values from ISO: 8608. For rough runway, the values of C and N are 8.1 × 10−06 and 2.1, respectively. The simulations were carried out at various constant speeds, and results were obtained.

This article considers motion planning of a redundant serial link manipulator in fully submerged underwater scenario in the presence of obstacles, modelled as point objects. The proposed trajectory planning is based on minimizing the energy required in overcoming the hydrodynamic effects, and in the same time avoiding both obstacles and singularities. The presence of redundancy in joint space enables to choose optimal sequence of configurations and associated motion rates. The proposed approach is applied for motion planning of a three degrees-of-freedom planar manipulator avoiding a point obstacle and solved.

Remote surveillance of hazardous areas necessitates the deployment of mobile robots for carrying out planned work. These robots are equipped with sensors to enable monitoring and recording of the critical parameters of the remote hazardous areas. The sensed parameters need to be localized to gain better insights of site conditions and take corrective actions. By forming a system that offers combination of human intelligence with mobile robot’s reach and onboard machine intelligence, a teleoperated mobile robot provides a flexible and versatile solution for remote safe operation (Mukherjee et al. in National Symposium on Nuclear Instrumentation, Mumbai, Nov 2013) [1]. In addition, the robot’s ability to build the map of remote environment and self-localize with reference to map all by itself provides a basis for overlaying of sensed data onto the map for easier visualization and assessment by the user. This paper addresses the design and development of an indigenously developed mobile robot capable of carrying out surveillance and map building in remote environment.

Moving object detection and tracking has significant importance in machine vision and robotic applications. The objective of tracking is to ensure that the targeted object always remains in camera view. In this paper, Speeded-Up Robust Features (SURF) technique is used to develop a robust automated target tracking system that relies on local features (corner, edge) rather than global features (intensity and shape) of the object. SURF provides an efficient scale- and rotation-invariant detector that is robust to partial occlusion and noise. System based on SURF presents more accurate and efficient automated target tracking system. This system is developed for the application where user has to locate and orient camera manually to target an object in its workplace.

The article presents development of an eight-wire passively driven parallel manipulator and discusses its workspace and stiffness behaviour. The uniqueness is in the passively driven design. The device can be used in biomechanics study of human movements and for calibration of manipulator arms, among many others. Manipulator kinematics and the force closure workspace (with inextensible wires) are analysed. A procedure is presented to numerically determine the workspace. Task space stiffness at end effector is examined through a stiffness tensor for directional stiffness behaviour in the workspace. A stiffness index characterizes the degree of isotropy of the stiffness. Experimental validation of forward kinematics and simulation results of force closure workspace and stiffness behaviour of actuated manipulator are reported.

This paper is concerned with a compliant-hinge mechanism in an assistive chair that does not use external power in aiding the elderly and arthritics in stand-to-sit and sit-to-stand manoeuvres. The mechanism, attached to the seat of the chair, acts like a nonlinear torsion spring that is effectively pivoted to the frame. A pair of semi-circular open-section shells that are rigidly connected to each other and fastened to the chair frame comprise the spring. A cam profile on a guide plate enables the shells to deform transversely even as they twist to provide customized torque–angle characteristic as per the weight of the occupant. The formulation of the design specification based on biomechanical considerations, kinetics of sitting and rising in a chair, kinetoelastic modelling of open-section shells, a new energy mapping method of designing the guideway for the shells, and simulation of the entire unitized compliant spring mechanism are presented.

In this chapter, we have focused on the link type active steering bogie with an actuator placed in the center of the bogie. The operating principle of actuator is to control the yaw movement of the wheel set according to the location of the vehicle on the track. Active steering vehicle has been co-simulated where the steering vehicle model and control algorithm are modeled in multi-body simulation (MBS) software VI-Rail and MATLAB Simulink environment, respectively. As the railway tracks have different curvatures and cant/superelevations, the estimated steering angle varies from time to time, which affects the dynamics of the vehicle. Hence, the control algorithm is used to control yaw angle of the vehicle. By implementing controlled steering, a significant improvement on ride comfort, derailment speed, creep forces, and creepage have been observed, which helps to reduce the wheel–rail wear and the noise.

The robots moving on a rope are an interesting domain with research potential and various applications. This paper reports on the design of a rope climbing robot design and its analysis. The rope climbing robot uses wheels powered by the DC motors for climbing the vertical rope. It can traverse horizontal ropes as well. The springs attached to the wheels are used for passive clinging of the robot to the rope. The stiffness of the spring was calculated on the basis of the payload and the motion capabilities of the robot. The proposed design gives two degrees-of-freedom (DOF) to the robot, i.e., translation and rotation about the rope. The power required for climbing at different inclinations is reported. The design proposed here is of low cost, easy to build, and control. It can be useful for surveillance purposes, for delivering help in disaster situations, inspection of cable suspension bridges, power plant chimneys, and cooling towers.

It is becoming increasingly important to simulate the dynamic behavior of complex systems in order to make real-time predictions about the performance of the system. The modeling technique has to be computationally efficient and accurate. In this work, a novel object-oriented modeling method is presented, which is characterized by high modularity and computational efficiency. This method is particularly useful for performing real-time simulations and is characterized by a high degree of configurability, scalability and is found to be faster than the established multibody simulation software like ADAMS and DYMOLA. The developed method can be used to predict the dynamic behavior of open-loop as well as closed-loop systems in real time. The method is demonstrated by using it to model a vehicle suspension system for predicting the dynamic response of the mechanism.

Future fast breeder reactors envisage the use of Offset Handling Machine for ex-vessel handling. In order to avoid the inadvertent lifting of transfer pot (TP) by in-vessel handling machine, an actuator operated four bar clamping mechanism is being used. Kinematic analysis of the mechanism is very important to ensure the positional accuracy of clamping link. Accurate determination of forces in links are essential for linear actuator sizing, which necessitates the need for dynamic analysis. A code has been developed for the kinematic and dynamic analysis of the mechanism. Position analysis ensures that clamping link moves out thereby enabling the easy removal of TP. Analysis shows that maximum velocity at the tip of clamping link is very small and hence do not influence the positional accuracy. Dynamic analysis with and without considering the effects of friction are carried out and pushing/pulling force requirements of clamping mechanism are established.

Telepresence system provides interfaces to remotely teleoperate robot and execute hazardous task. These tasks are generally executed by human operator in master–slave mode. Telepresence interface provides a small haptic device to manipulate robot, stereoscopic view to see the environment and moreover force reflection capability. Bilateral master–slave tele-manipulation depends upon operator’s experience and agility to a large extent. In this article, we discuss the concept of 3D mouse and path-planning functionality for an autonomous stereo vision guided telerobotics system. These augmented reality functionalities will assist operator to perform pick and place operations more efficiently.

This paper presents a defect-free analytical synthesis of four-bar linkage for four precision positions using the proposed algorithm. The proposed algorithm poses several constraints such as extremity of transmission angle, Grashof conditions, and the minimum perimeter condition, to obtain a defect-free and compact four-bar linkage. Besides these constraints, one more constraint is applied which keeps the moving pivot of driving link outside the wedge-shaped region, which is consistent with the Filemon’s construction. This constraint ensures that mechanism has no circuit defect. In this work, motion generator mechanism is synthesized by considering four precision positions. This work proposes an algorithm named as perimeter algorithm, and a realistic example is considered to demonstrate the effectiveness of the algorithm.

Autonomous Guided Vehicle (AGV) is an ensemble of various parts and subsystems and hence prone to operational errors induced due to manufacturing and assembly tolerances. Moreover, the controls of the various actuators are also prone to inaccuracies due to technical limitation of the control hardware. These mechanical and control limitations along with actuator latencies manifest cumulatively as errors in the motion of the AGV. In presence of these errors, vehicle does not faithfully follow the commands issued by the control algorithm and in turn results in path following and stopping inaccuracies. It is imperative to minimize the effect of these errors to achieve the desired repeatability and precision required for the satisfactory operation of the system. The current paper discusses the methodologies for measurement and compensation of systematic errors like difference in wheels orientation and alignments, offset of laser navigator, uncertainty of wheel diameter, etc. The paper proposes formulation of the tuning procedure for a quad configuration AGV. The paper also presents the resulting improvements achieved in AGV performance, in path tracking and positional repeatability at material transfer stations.

This paper presents the design of a gripper whose fingers can passively adapt to the shape and size of the object being grasped. Passive shape adaptive behavior of fingers is obtained by implementing underactuation, thus reducing the amount of sensory input required for grasping. The gripper has two identical fingers placed opposite to each other. Each finger has two phalanges and is actuated using a backdrivable electric motor via a linkage mechanism. Thus, the gripper has four degrees of freedom and two degrees of actuation. First, optimization procedure for sizing gripper mechanism and associated variables are explained. Subsequently, learnings from the realization of first two prototypes are presented.

This paper presents the design and control scheme of a mobile manipulator used for radiation survey of Cyclotron vault and cave regions. It discusses the mechanical design of the traction system, the steering gear, and the scissor mechanism. Selection of steering system based on terrain condition and power requirement is also discussed.

In this paper, we focus on the problem of onion harvesting using one possible methodology. The current method of harvesting onions in India involves farmers sitting on the ground and plucking the onion withholding the stem of the crop. We have developed a prototype of manually operated onion harvester which will increase the efficiency of the harvesting and reduce the manual labor. To visualize our idea for mechanism, we made an interactive geometry model in Cinderella software. For validating our results, we did static force analysis and ground penetration testing. The mechanism can be potentially automated which will increase the efficiency even further.

Articular cartilage is a soft tissue between the mating bones of a synovial joint. It prevents direct contact while facilitating load carriage and lubrication with very low friction and wear. Modeling of a synovial joint involves nonuniform geometry of mating bones, available from point cloud data, separated by cartilage. This work proposes a simplified yet efficient model of a ball dropped in a bowl lined with a cartilage layer, to emulate the contact mechanics between mating bones. Multibond graph submodels for the ball and bowl are used to represent their rigid body mechanics. The nature of the intervening cartilage layer is characterized by a nonlinear C-field. Simulation code has been written algorithmically, directly from the bond graph model. Results indicate that the proposed model holds significant promise for applications in biomechanics.

In this paper, an attempt has been made to develop a framework for closed-loop impact modeling of a multi-arm robotic system mounted on a servicing satellite while capturing a tumbling orbiting object. When the satellite is in broken state or does not have provision for grapple and tumbling, the interception is very difficult. In such cases, interception using multi-arm robotic system can be appealing as this will certainly increase the probability of grasp in comparison to a single-arm robot. When multiple arms of a robot will capture only one target object from different points of contact, then it is termed as closed-loop impact. In this paper, first, the dynamic models of a multi-arm robot and a tumbling orbiting object are obtained. The target dynamics has been modeled considering it to be a rigid body. Then, the three phases of the capturing operation, namely, approach, impact, and postimpact have been modeled. Efficacy of the framework is shown using a dual-arm robot mounted on a servicing satellite performing capturing operation when both arms of robot capture a single target object. The effects of relative velocity and angle of approach on the impact forces would also be investigated.

A Spring-Lever (SL) model with two degrees of freedom is a lumped model for a single-input-single-output (SISO) compliant mechanism just as a spring is a single degree-of-freedom model for an elastic structure under one load. Three parameters of an SL model help visualize compliant mechanisms in a database juxtaposed with a feasible map constructed using quantitative specifications of a given design problem. In the past work, this approach is shown to be effective in selection and re-design based method of designing compliant mechanisms. This work extends the method to designing compliant mechanisms at multiple length scales through non-dimensionalization of two stiffness parameters in the SL model. Nonlinear large-displacement behavior of compliant mechanisms and user-specifications are accurately captured in non-dimensionalized stiffness maps. After describing the procedure for constructing non-dimensionalized stiffness maps, the method of designing compliant mechanisms using the maps is illustrated through examples and case-studies.

This paper suggests a modified thresher machine design for minimizing the problem of choking in the concave. As surveyed in the district of Dantaramgarh, Rajasthan, the major hitch faced by the farmers in employing multi-crop thresher machine is the choking of straw and chaff in concave clearance as the speed of feed is increased. As the feed is increased, the chaff aggregate increases considerably and is forced down the clearance and chokes it subsequently. To resolve the issue, a design was suggested that entailed a concave frame to hold the concave instead of being an integral part of mainframe of machine. The mechanism introduced to move the concave frame was termed as anti-choking mechanism.

In the upcoming fuel fabrication facility for Indian prototype fast breeder reactor (PFBR), automation of fuel fabrication is required to be done. Fuel pin carries spacer wire wrapped around its surface. This pin contains groove at bottom end plug for bead entanglement. Wire has to be welded on the bottom end plug. Crimping is done to restrain the tension in the wire before weld bead. The scope of this paper is to present development of an automated system required for remote handling of wire wrapping process. A prototype has been designed to simulate various processes of wire wrapping. This is an automated system for handling of pin and wire wrapping processes.

Fabrication of metallic (U-6%Zr) slugs involves melting of binary alloy under vacuum and injection casting into quartz moulds at high pressure. Injection casting system contains high vacuum, high pressure, motion control, crucible handling and glove box pressure control systems in addition to melting, preheating and cooling systems inside a glove box. Injection casting process is the primary and important operation of the metal fuel fabrication process and is in the critical path linked to productivity. It is pertinent to implement high level of automation to improve batch mode productivity, accuracy and reduce risk hazards associated with radioactivity. The technology development and process automation on fabrication of U-6%Zr binary alloy and qualification experiences are outlined in this paper. This paper deals with the experience gained in process automation of injection casting equipment, crucible lifting mechanism and its integration inside glove box which is maintained at high purity inert atmosphere.

The Prototype Fast Breeder Reactor (PFBR) has eight Steam Generators (SG), each with 547 tubes connecting top and bottom headers. The integrity of these tubes is ascertained using periodic In-Service Inspection (ISI) procedures. Two-Axis Tube Locator Module (TLM) is a robotic manipulator designed to be used to precisely locate all 547 tubes. The difference in the device work plane and the tube sheet plane is mainly due to error from tolerances in fabrication and error due to mounting the device. These errors hinder the accurate positioning of inspection device over the tubes for inspection. In this work, a novel approach to calibrate the TLM is attempted by using motor encoder as sensors, to calibrate the TLM without using any external calibration devices. In this work, a three-point calibration is used to compute transformation matrix using two-axis motor encoder as sensors, for measuring the displaced position of calibration point tubes and using SVD on the correlation matrix formed from the original and transformed points. Even though three independent measurements (x, y, z axis) are required to spatially ascertain the positioning error of the probe with respect to calibration point tube, it proved that planar 2D measurement using readily available servo motor encoder sensors itself is adequate for the calibration of TLM without much loss of accuracies. The degenerated sensing reduces the cost, effort, and time for calibrating the TLM for use in inspection.

Prototype Fast Breeder Reactor (PFBR) has eight Steam Generators (SGs). Inspection of SGs requires a remote tooling to reach the probe pusher module to each of the 547 tubes present. Since the tube sheet reach has a planar workspace, a two-axis Selective Compliant Assembly Robotic Arm (SCARA) type of manipulator suits well. However, the geometry and size of the manipulator are based on the workspace and space constraints which are very well represented in the kinematic studies through the DH parameters. However, the position or velocity inverse kinematics solution for the tube to tube movement results in discrete position or velocity points. So for precision movements with good control on speed and position, we prefer position and velocity-based moves through the motion controller. In order to maintain continuity on accelerations and jerks while controlling velocity points require a choice of higher order polynomial. This paper presents the quintic interpolation method (quintic polynomial trajectory) for planning a joint trajectory of two-axis robotic arm. The quintic interpolation and the case study of PFBR steam generator inspection are presented. The quintic interpolation ensures the continuity of displacement, velocity and acceleration for the planned motion of joint trajectory of two-axis robotic arm.

A prototype of a system is a numerical model. It is used to generate large amount of data and can be a successful replacement to experiment,which is often difficult to conduct and moreover is expensive. This article deals with the development of two models of rotor supported by deep groove rolling-element bearings to study the dynamic response. The bearing models are 5-DOFs and multi-body dynamics is developed using Matlab–Simulink and the bond graph environment. The systems of equations generated by modeling rolling-element bearing using these two approaches are theoretically simulated. The effects of speed variations in the dynamic response using these two models are investigated. The three regions namely, periodic, quasi-periodic, and chaotic are seen on the 5-DOFs rotor supported by rolling-element bearing model with increasing speed, whereas bearing model based on multi-body dynamics approach gives only chaotic response for each speed. Thus, using these two modeling approaches, a comparative study of the magnitude and characteristics of rotor motion can be done, and can be used to infer the vibratory nature of rotor in rolling-element bearing.

Compliant mechanisms have found applications in high-precision micro-measurement, microfabrication, micro-manipulation, and other areas. These mechanisms have inherent advantage of being highly precise, backlash-free, low energy consuming, and frictionless and hence durable. However, typical range of motion and speeds with these mechanisms are limited because of large deformation nonlinearities and complex dynamics. Furthermore, achieving higher range of motion with much lower stroke non-collocated actuator is another challenge. Displacement amplifying compliant mechanisms, found in the literature, provides solution for higher range with lower stroke actuation. However parasitic errors are high, complex structure with several moving masses makes their usage in dynamic applications (higher speeds) difficult. We propose, in this paper, alternate method using resonant displacement amplification using simple double parallelogram compliant mechanism (DPCM) toward higher but fixed speed applications. With limited stroke of actuation, we develop control algorithms to maintain a stable limit cycle. Parametric study using lumped mass model offers pathways for design decisions and unfolds interesting results. Experimental results validate the proposed method but point to limitations of the lumped mass model.

In this paper, dynamic analysis of a ladder chassis frame has been done using Ansys. First, modal analysis of the chassis was done using structural steel material. The first six nonzero natural frequencies and their corresponding mode shapes were extracted. It was observed that the second natural frequency of the chassis was close to the engine excitation frequency at idling condition, and the fifth natural frequency was close to the engine excitation frequency at high-speed cruising condition. Thus, the chassis may experience structural resonance at these conditions. The chassis design was optimized so as to obtain the natural frequencies in the desired range, and avoid the possibility of resonance. A harmonic response analysis was done on the original and optimized chassis to check the response under a harmonic force.

In the present work, dynamic analysis of a spring, mass, and damper-based nonlinear active vibration absorber, and a nonlinear primary system are carried out by time-delay acceleration feedback. The primary system is subjected to multi-harmonic hard excitation and parametric excitation. It is proposed to reduce vibration of both the primary system and the absorber by attaching a lead zirconate titanate (PZT) stack actuator connected in series with which it acts as an active vibration absorber. Due to the external excitation, strain is developed in the PZT sensor, which produces voltage and this voltage is converted into a counteracting force by the PZT actuator to suppress the vibration of the primary system. Second-order method of multiple scales (MMS) is used to obtain the approximate solution of the system. Frequency responses and time responses for the different parameter of the system are studied for simultaneous superharmonic and subharmonic resonance conditions.

The Steam Generators used in the Prototype Fast Breeder Reactor have sodium on shell side and water/steam on the tube side. Tube inspection and qualification of all 547 tubes, enhances the safety and reduces the operation cost by increasing plant availability. In this work, a two-axis planar reach robotic arm called as Tube Locator Module (TLM) is used for reaching and orienting the Remote Field Eddy Current (RFEC) testing probe at the exact location of individual Steam Generator tube, and the probe is pushed through the entire tube length for inspection and qualification of the same. A conventional method of inverting the Jacobian and using a pseudo inverse will help in running the actuators in joint space to reach the desired position of the end effector. However, as pseudo inverse suffers numerical stability close to singularities of the manipulator, hence it is proposed to use the damped least squares pseudo inverse method by introducing a damping factor to improve the stability. Higher damping factor increases the stability of manipulator, even when the manipulator moves closer to its singular configurations. However, higher damping factors lead to more tracking error in the end-effector trajectory. Hence, in this work, based on the tracking errors and the geometrical constraints, an optimal damping factor is arrived at for the smooth motion of the TLM. This paper also deals with the manipulability study of the TLM to understand the singular configurations, and apply the damping factor to stabilize the joint angular velocities without causing much error in the end-effector trajectory.

Remote-center motion (RCM) mechanisms employing compliant links provide friction-less and backlash-free motion of a part of mechanism about a remote-center of desired radius. Such precision mechanisms find use in many medical and engineering applications. A partial RCM mechanism employing an L-shaped cantilever beam is proposed, for the first time, to enable a mounted rigid-link to rotate precisely about one of its edges. The mechanism is conceived with multiple arrangements of the L-shaped cantilever beams to hold the rigid-link against another fixed link such that the “remote-center” of the mechanism coincides with one of the edges of the mounted rigid-link. The link and L-shaped cantilever are connected by means of a higher pair joint, thus a partially compliant mechanism. Remote-center coordinates are located by carrying out nonlinear “finite element analysis” of the cantilever beam. Further, the mechanism is fabricated and experiments are carried out to verify its working at high precision.

Prototype Fast Breeder Reactor (PFBR) has eight Steam Generators (SGs), four in each secondary loop for exchanging the heat from the secondary sodium to water/steam. Sodium is present in the shell side and water/steam in the tube side. Internationally, it is seen that SGs are the key factors for the plant availability and hence, SG tube integrity is of prime importance. Significant progress has been made around the world both on the Remote Field Eddy Current (RFEC) testing and the remote automation of the tube inspection. An indigenously designed and built device called PFBR SG Inspection System (PSGIS), which is first of its kind in the world for FBR SGs is designed and tested on different mock-up test setups and qualified for the use in actual PFBR SG. The device has been used to inspect all the SG installed at PFBR site. This paper brings out the details of the remote tooling designed and used for the inspection of PFBR SG tube.

This paper investigates the prospects of making linkages made of bamboo pieces for realistic use by taking popular scissor lift as a test case. The paper through prototyping shows that because of weakness in revolute joints formed on bamboo pieces, the popularly used parallel-plane scissor linkage leads to excessive lateral sway. The paper further shows that the lateral sway can be significantly reduced be merely changing the linkage design to triangular-prism-shaped scissor linkage. The paper also formulates an optimization problem where the objective is minimization of actuation effort of scissor lift and optimization parameters are the free-lengths of the springs that are used to partially statically balance the gravity potential energy of the scissor lift. We chose to use normal nonzero-free-length springs instead of well-studied zero-free-length springs since it is less cumbersome and easy to assemble. We could practically demonstrate a $$60\%$$ reduction in actuation effort. While simple, (1) recognition of advantages of triangular-prism-shaped scissor linkage in the context of making linkages with bamboo and (2) the spring parametrization and manual optimization in the context of static balancing are novel.

Dynamic model of an underwater robot is nonlinear in hydrodynamic parameters such as added mass, damping, etc. The hydrodynamic coefficients vary with time and configuration of the robot. This paper presents a modeling technique for the Underwater Vehicle-Manipulator System (UVMS) using the DeNOC matrices. Furthermore, as a starting point, some simple hydrodynamic experiments were performed which are used to validate the hydrodynamic simulation in MATLAB environment. For these simulations, the hydrodynamic coefficients were considered to be constant throughout the simulation of the manipulators. Two experiments were performed. In the first experiment, free fall of one-link arm was considered, and in the second, free fall of a two-link manipulator was considered. The simulation results obtained were found in good agreement with the experimental results, even with the constant hydrodynamic coefficients, because of the simple structure of the experiments.

This paper enumerates the design and synthesis of a mechanism for a fuel briquette compacting machine. The briquettes are made of a mixture of husk (rice or wheat or any other) and animal waste in appropriate proportions and compacted in the machine. Several experiments were initially conducted to arrive at the right proportions of water, husk, and dung, and to determine the force to compact the biomass. The pellets were dried in the sun and burnt in a stove. The final specifications of the machine were arrived based on these simple trials. There were several challenges in the machine development. The biomass mixture tends to cake and harden if the machine is left idle for long. It is not desirable for a briquette to crumble both in a wet as well as a dry state. The mechanism has to handle these requirements and as the machine, is to be manually operated frictional effects and any tendency to jam ought to be minimized. The engineering drawings of the machine are being freely distributed to rural mechanics who are desirous of replicating the machine, after observing the machine in action at CTARA at IIT Bombay. Several machines have thus been built and are operational in many villages. The paper covers such aspects and how a compact machine was arrived at through synthesis of an appropriate mechanism that is inherently not easily prone to “jamming”. The synthesis is based on techniques derived from symmetric coupler curve generation.

This paper deals with trajectory tracking control of a car-like robot. By exploiting the differential flatness property of the system based on the dynamics, a trajectory tracking controller using flatness-based control techniques is designed. A singularity in the system for the chosen control inputs, which does not allow direct application of feedback linearization control, is identified and this singularity is overcome by applying the dynamics-extension algorithm to obtain a dynamic feedback linearized controller. This controller results in asymptotic tracking convergence of the system’s trajectory to the reference trajectory. Through numerical simulations, the control system is shown to track prescribed trajectories satisfactorily even in the presence of parametric uncertainties.

Master–slave manipulators are commonly used for remote handling in nuclear environments. They are generally mechanical, electrical (servo), or power manipulators. They need rigid support or rigid moving platform in the remote area for installation, they cannot be deployed in places, where such preinstalled rigid supports are not available. In such cases, the slave arm of the manipulator could be suspended on an EOT crane and taken to the site for remote operation. BARC has developed one such suspended manipulator and deployed it for remote operation in a radioactive cell. The crane, being flexible, poses challenges in position control of the end effector. Unlike manipulators with rigid base, the position and orientation of the end effector of a suspended manipulator depend on its inertial parameters, in addition to its kinematic parameters. We have developed an algorithm for solving the kinematics of a six degrees of freedom suspended manipulator. The algorithm is validated experimentally on a three degrees of freedom prototype arm.

Coolant channels of PHWRs have various life-limiting issues due to the existence of a number of degradation mechanisms. In order to ensure safe operation of the coolant channels, various types of tools and techniques like BARCIS, INGRES, Scraping Tool, ID measurement tool, Sag measurement tool, etc., have been developed for monitoring the integrity of the components as an In-Service Inspection activity. Additional tools are being developed as future phase of inspection requirements, such as tools for replication of surface flaw, in situ mechanical properties measurement, and visual examination, etc., for creation of reference data by baseline inspection and to monitor its health to ensure the integrity during operation. This will also provide database for assessing residual operating life of coolant channels, necessary for decision-making. In order to fulfill the regulatory requirement of carrying out large number of inspections for deterministic assessment of the healthiness of the coolant channels of 220 MWe PHWRs, a Tool Delivery System (TDS) has been developed and is under endurance test at BARC. This system would facilitate better and efficient inspection of the coolant channels, thereby reducing the inspection time and man-rem consumption. It facilitates the use of a combination of three or four individual tools; having multiple features to reduce the inspection time. TDS is envisaged to be used for the operation of almost all inspection/examination tools heads. All these inspection heads are connected to control system through a common umbilical cable. The umbilical cable consists of a number of electrical power and signal wires, hydraulic, and pneumatic hoses, etc., required for various types of tools. The tool head is connected to the umbilical cable manually using quick connection type connectors. The paper describes various sub-system and components of TDS, their functions, testing, and future plans.

This paper for the first time in literature studies the quasi-static behavior of a smooth object when it is being grasped with two rigid point fingers without friction and in the absence of external forces. A simple model of slip for the point finger over the object is proposed and the evolution of the traces of the point of contact of the fingers are computationally determined. The kinematic response of the object as viewed from one finger is assessed with the evolution of the slip. The convergence of the two slip-loci to two distinct points or a single point imply a successful or failed grasp endeavor, respectively. It is argued that the slip-loci are geodesics on the smooth object which gets temporally parametrized, as slip evolves.

In this paper, a modified approach to stabilize the ballbot is presented using reaction wheels. Unlike recent ballbots, reaction wheels are added to the system. A mathematical model is formulated with the help of Lagrangian mechanics to the modified ballbot. The controllers PID and LQR are considered for position balancing. The effect of reaction wheels to the ballbot is studied and compared to the performance of ballbot without reaction wheels case.

This paper presents the teleoperation of multi-DOF cyton robot using visual feedback which carries depth information. Teleoperation system consists of PHANTOM Omni device which was set as master and cyton robot as a slave robot. The motion of the slave robot was controlled through direct angle mapping of joints with master. Teleoperation system also uses visual feedback for enabling effective remote manipulability. Visual feedback contains side-by-side frames of left and right IR cameras attached to the Raspberry Pi compute module. Two cameras attached to compute module will capture simultaneous side by side frames and transmitted through network. 3D view of the remote location will be perceived by the user using 3D video transmission in side by side format. Live stream was enabled in smartphone and attached to the VR headset.

Liquid Handling Robots serve to automate the small volume liquid transactions for handling solutions in the research laboratories associated in the field of chemistry, biology, pharmacology, and more. They are used either to eliminate the tedious manual work required in carrying out a large number of pipetting operations or for handling potentially harmful solutions. Liquid Handling Robot is developed for executing simultaneous liquid transaction reactions on a large number of samples to extract DNA molecules from the living cells. This DNA separation reaction is performed by magnetic bead separation method. Multichannel electronic liquid dispensing head is developed to handle biological solutions in microscopic quantities. A robotic positioning system is designed and developed for maneuvering this liquid dispensing head as per the application requirement. A magnet module consisting of an array of permanent magnets operated by a rotary solenoid is developed for DNA extraction. The robotic positioning system and dispensing head is commanded by a customized software interface which provides high throughput. The system is designed for carrying liquids ranging from 30 to 300 μl with repeatability of <5%. The paper discusses the general overview of Liquid Handling Robots, magnetic bead method of DNA extraction, design of a multichannel micropipette, and other major components of the system.

Bionic robots, imply the robots which are inspired by biological life forms. The manipulator robots inspired from elephant trunk are good example of bionic robots. These are continuous robots with bending backbones and high degrees of freedom. Ideally, the compliant nature of such manipulator delivers infinite degrees of freedom, which makes it difficult to control them at the space task. However, all these degrees of freedoms cannot be actuated, thus these robots are always underactuated, i.e., they provide vast configurations with few inputs. In this paper, a multi-section bionic manipulator, namely the compact bionic handling assistant (CBHA), is dynamically modeled using bond graph. Assuming planar robot that contains a single concentrated mass per section, dynamic equations for each bellow are derived by means of bond graph modeling. Simulation results using lumped model are shown to validate the model.