Frontiers of Assembly and Manufacturing

Frontmatter

Fixturing, Grasping and Manipulation in Assembly and Manufacturing

Abstract

Assembly and manufacturing automation involves different problems, most of them derived from the physical interaction between parts, where any imprecision could produce important failures and consequently an increasing of the manufacturing costs. Properly task planning and programming, as well as the calibration of the involved systems, are quite frequently more complex than the task execution itself, and this is somehow strengthened by the continuous development of more and more versatile tools, with sophisticated features and high flexibility in their capabilities.

Raúl Suárez

Dual Arm Robot Manipulator and Its Easy Teaching System

Abstract

The dual arm robot manipulator has been developed and it easy teaching system has been developed also. The manipulator consists of two industrial 6-DOF arms and one 2-DOF torso and it was designed for the assembly automation of the automotive parts. Two-arm robot system has more advantageous than the traditional single arm robot system. But it is more difficult to teach the dual arm robot system. In this paper, the research results on the dual arm robot manipulator and its easy teaching system will be introduced.

Chanhun Park, Kyoungtaik Park, Dong IL Park, Jin-Ho Kyung

Calibration of Relative Position between Manipulator and Work by Point-to-Face Touching Method

Abstract

This paper presents a new technique for simple, highly accurate calibration of relative position between a robot arm and a target work. This technique can shorten calibration time and reduce production cost. In this study, we adopted point-to-face touching for simple, highly accurate calibration. Point-to-face touching means to touch work surface with one point of an arm tip tool. Robot arms can get constraints of work position by difference between actual touching point and ideal one, and can calculate work position error with linear programming problem. Effectiveness of the calibration technique has been verified by experiments. By repeating experiments without changing environment and conditions, repeatability of the proposed calibration technique is verified by confirming dispersion of the calibration results. Precision is also verified by trying of robot arm to examine peg-in-hole task without force control.

Toru Kubota, Yasumichi Aiyama

Cutter Accessibility Analysis of a Part with Geometric Uncertainties

Abstract

In designing a holder part of a large stamping die, designers must consider not only the functional property of the part, but also its manufacturability. The holder part is usually produced by cutting and engraving table, wall, slot and pocket features into a raw cast object. The raw cast object has inevitable large shape errors. It generally has 5 to 10mm shape difference from the nominal CAD model. This shape uncertainty causes various manufacturability problems in the milling process. The most serious problem is unexpected collisions between a cutter and raw cast object. They cause possible tool breakages and become obstructions to the cutter access to some regions on features. Since such features are not properly machined, costly re-designing the holder part is necessary. In this paper, the authors propose a manufacturability analysis system which can detect such un-machinable features caused by the shape uncertainty of the raw cast object. Proposed system computes a geometric model of a holder part with the maximum shape error by modifying the CAD model. Inverted offsetting and cutting simulations are successively applied to the model to extract the un-machinable region on the features. A system is implemented and some computational experiments are performed.

Masatomo Inui, Kazuhiro Maida, Yuji Hasegawa

Automatic Determination of Fixturing Points: Quality Analysis for Different Number of Points and Friction Values

Abstract

This paper copes with the automatic determination of fixturing points on 2D and 3D free-form objects, for any number of fixturing points and a variable friction coefficient at the contacts. An approach is proposed that, starting from an initial set of points, successively finds a better set by changing only one point at a time following an heuristic search procedure that uniformly explores the object surface. A software tool that implements this approach is also presented. This tool also allows to analyze the quality of any given set of fixturing points, which has allowed us to determine how many points are necessary for a given coefficient of friction in order to fix 2D and 3D objects with a given quality. The tool has been released as open software.

Jan Rosell, Raúl Suárez, Francesc Penalba

Contact Trajectories for Regrasp Planning on Discrete Objects

Abstract

Manipulation tasks, in general, require a grasp change on the object during its execution. The manipulation problem can be solved by simply rolling or sliding the fingers on the object surface, the so-called regrasping approach. This paper provides an algorithm for regrasp planning of 2D and 3D discrete objects, such that the regrasp trajectory of each contact ensures a force-closure grasp (i.e. a grasp that resists external disturbances) while the regrasp motion is performed. The proposed approach takes advantage of a sampling-based method that quickly explores the grasp space, and relies on the use of independent contact regions and non-graspable regions, which provide large regions of the force-closure or non force-closure subspaces starting from a single sample. Application examples are included to show the relevance of the results.

Máximo A. Roa, Raúl Suárez

Modeling of Two-Fingered Pivoting Skill Based on CPG

Abstract

Two-fingered pivoting is a typical example of human dexterous manipulation interacting adaptively with the environment. In this paper, we construct a skill model of two-fingered pivoting manipulation based on CPG (Central Pattern Generator) with five neurons. The CPG drives a virtual hand, which consists of a wrist, a palm, a thumb and an index finger, rhythmically to achieve robust pivoting through the interaction with the environment. Its adaptability is demonstrated in dynamic simulation of box pivoting. The virtual hand successfully adapts to environmental changes such as sudden decrease of the friction coefficient of the floor.

Yusuke Maeda, Tatsuya Ushioda

Micro/Macro Assembly and Disassembly

Abstract

The technologies for assembly and disassembly in manufacturing are rapidly advancing toward meeting the new requirements and challenges emerged from the following fronts: 1) The need to fabricate a high complexity of micro systems integrated and packaged in 3D with various heterogeneous parts, components, and interconnections, including electrical, optical, mechanical as well as fluidic means. 2) The drive to establish intelligent/smart assembly and disassembly for manufacturing to reach a new level of autonomy, quality and productivity by taking full advantage of the advancement in robotics and machine intelligence. This chapter, Micro/Macro Assembly and Disassembly, have chosen 6 papers to present, covering the state-of-the-art technologies in assembly and disassembly developed for the above two fronts: the first 3 for micro assembly and the latter 3 for intelligent assembly and disassembly.

Sukhan Lee

Assembly of 3D Reconfigurable Hybrid MOEMS through Microrobotic Approach

Abstract

Micro-assembly has been identified to be a critical technology in the microsystems technology and nanotechnology. Increasing needs of MOEMS (Micro-Opto-Electro- Mechanical Systems) for microsystems conducts to development of new concepts and skilled micro-assembly stations. This paper presents a 3D micro-assembly station used for the reconfigurable free space micro-optical benches (RFS-MOB) which are a promising type of MOEMS. Designed parts of RFS-MOB are assembled by using the developed micro-assembly station. The flexibility of the micro-assembly station provides the possibility to manipulate a variety of micro-components. The RFS-MOB design enables to reduce adhesion forces effects during releasing operations. Experimental results are shown and validate the effectiveness of the micro-assembly station and micro-assembly strategies.

Kanty Rabenorosoa, Sylwester Bargiel, Cédric Clécy, Philippe Lutz, Christophe Gorecki

Modified Assembly Systems and Processes for the Mounting of Electro-Optical Components

Abstract

Optical interconnections have been used for years in long distance networks and gain more and more importance for optical applications on system and board level. With the integration of optical layers into printed circuit boards the functionality can be increased while the board size remains the same. The success of this technology depends in particular on the availability of efficient production solutions. Photonic packaging implicates basically three challenges for the placement of electro optical components. With a modified process sequence and optimized processes low cost mass production is possible. This article describes the conceptual design and the implementation of a continuous process chain into a modified standard assembly system.

J. Franke, D. Craiovan

Factory Level Logistics and Control Aspects for Flexible and Reactive Microfactory Concept

Abstract

Micro assembly and micro manufacturing, as well as micro factories are currently widely studied around the world. However, the research is typically focusing on single machines and not so much on integration of single processes and machines into wider process chains and larger systems with integrated material logistics. This paper discusses issues related to the realization of a larger scale integrated micro factory for the assembly of multi-part products. Special attention is paid on the logistical aspects and control concepts supporting flexibility and dynamic reconfigurability of the system. A scenario of a microfactory system as a holonic manufacturing system enabling the reactivity to sudden changes and failure situations is also presented.

Eeva Järvenpää, Riku Heikkilä, Reijo Tuokko

Development of Structured Light Based Bin–Picking System Using Primitive Models

Abstract

As a part of factory automation, bin-picking systems perform pick-and-place tasks for randomly oriented parts from bins or boxes. Conventional bin-picking systems can estimate the pose of an object only if the system has complete knowledge of the object (e.g., as a result of the geometric features of the object being provided by an image or a computer-aided design model). However, these systems require the features visible in an image to calculate the pose of an object, and they require additional setup time for an operator to register the reference model every time when the workpiece is changed. In this article, we propose a structured light based bin-picking system using primitive models with small amount of prior knowledge. To obtain a reliable 3D range image for comparison with conventional systems, we use a structured light sensor with gray-coded patterns. With the 3D range image, the pose of the object is estimated with the use of primitive segmentation, rotational symmetric object modeling, and recognition. Through experiments using an industrial robot, we validate that the proposed method can be employed for a practical bin-picking system.

Jong-Kyu Oh, KyeongKeun Baek, Daesik Kim, Sukhan Lee

Airframe Dismantling Optimization for Aerospace Aluminum Valorization

Abstract

Seeking the most cost-effective process, dismantlers must continuously make decisions while they part and shear out a plane. The mathematical model presented optimizes the profitability of aircraft dismantling process by determining which airframe entities must be sheared and sorted prior to shred its components or which entities must be directly shredded. The model also identifies which shredded components should be sorted in order to upgrade recovered materials composition. Until now, disassembly sequences generation and disassembly planning methods have been elaborated based on assembly connection types and generic mathematical models have been published. Most of the time, these approaches are time consuming and require efforts to be adapted to a specific product. The model proposed here is aircraft-oriented and is not only based on assembly connection types and fasteners classification which are considered as being too restrictive. Knowing that an airplane is made of about 60 % of aluminum alloys and that aluminum recycling could considerably reduce the aerospace industry’s ecological footprint, the model focuses on aircraft aluminum recovery.

Julie Latremouille-Viau, Pierre Baptiste, Christian Mascle

A Monitoring Concept for Co–operative Assembly Tasks

Abstract

In this paper we present a monitoring concept for co-operative assembly tasks. In cooperative assembly a human operator and a collaborative robot –cobot - share the work place and carry out assembly tasks. A generic assembly model is described for collaborative assembly tasks where two heavy parts are joined together. A cobot monitoring concept was developed with a software architecture considering functional, safety and quality aspects. The developed software was integrated and tested in an experimental cobot cell.

Jukka Koskinen, Tapio Heikkilä, Topi Pulkkinen

Manufacturing System Scheduling and Controlling

Abstract

This chapter reports on the recent advancement of manufacturing system scheduling and controling with 7 contributions.

In their article entitled “Printing pressure control algorithm of roll-to-roll web system for printed electronics,” Kyung-Hyun Choi, Tran Trung Thanh, Yang Bong Su, and Dong-Soo Kim propose a mathematical model of roll printing pressure control system and then design a full state feedback controller with gains determined optimally by using the modified genetic algorithm as well as the back-stepping approach. This study shows that, with the rapid development of sensor technology, electronic devices, and powerful computer, the proposed control algorithm of full state feedback controller can result in a control system with high precision.

Byung-Wook Choi

Printing Pressure Control Algorithm of Roll-to-Roll Web System for Printed Electronics

Abstract

In the paper, a mathematical model of roll printing pressure control system using the pneumatic system is proposed. By writing the system of dynamic equations in strict feedback form and applying the back-stepping theory, a full state feedback controller is obtained with gains that are determined optimally by modified genetic algorithm (MGA). A printing pressure control algorithm is given by using the proposed mathematical development and controller. The simulation results employed in Matlab/Simulink show the stability and high precision of the proposed algorithm.

Kyung-Hyun Choi, Tran Trung Thanh, Yang Bong Su, Dong-Soo Kim

Adding Diversity to Two Multiobjective Constructive Metaheuristics for Time and Space Assembly Line Balancing

Abstract

We present a new mechanism to introduce diversity into two multiobjective approaches based on ant colony optimisation and randomised greedy algorithms to solve a more realistic extension of a classical industrial problem: time and space assembly line balancing. Promising results are shown after applying the designed constructive metaheuristics to ten real-like problem instances.

Manuel Chica, Óscar Cordón, Sergio Damas, Joaquín Bautista

Construction and Application of a Digital Factory for Automotive Paint Shops

Abstract

To ensure competitiveness in today’s automotive market, growing emphasis is being laid on the collaboration of disparate engineering activities in manufacturing in the automotive industry. By applying virtual manufacturing, diverse engineering activities such as design evaluation, process & material planning, production flow analysis, and ergonomic analysis can be brought together to be performed in a single integrated model, viz., a digital factory. In this paper, we have suggested a procedure, consideration and expected effects for paint shop of automotive company. Therefore, we constructed a digital factory for a paint shop for an automotive company. By applying the digital factory to manufacturing engineering, it is expected that time and cost savings can be realized in many manufacturing engineering work in planning and new product development processes.

Yang Ho Park, Eon Lee, Seon Hwa Jeong, Gun Yeon Kim, Sang Do Noh, Cheol-woong Hwang, Sangil Youn, Hyeonnam Kim, Hyunshik Shin

Resource Efficiency in Bodywork Parts Production

Abstract

The need for even greater efficiency in handling resources is coming to be seen as a public duty in politics, commerce and research. At the same time this raises the question of what options are open to companies in the manufacturing industries - and, in particular, the OEMs and suppliers to the automotive industry - for reducing costs as well as deployment of resources and emissions. In addition to illustrating and analysing the relevance of this topic as far as forming technology is concerned, the following article discusses a selection of approaches that are being adopted in the Fraunhofer Institute for Machine Tools and Forming Technology with a view to reducing the consumption of resources, particularly in the bodywork parts production sector.

Reimund Neugebauer, Andreas Sterzing

Self-Tracking Order Release for Changing Bottleneck Resources

Abstract

In this paper a self-tracking order release strategy for job shop production with well-defined routes is presented. The release strategy is a combination of different known methods. The changing machine loads, caused by the different products manufactured in the job shop, are compensated. Additionally the constraint of the due date of each individual order is kept. Balanced load on all machines is achieved by controlling the sequence of released order and the release times. For the adjustment of the controller only the average WIP (Work in Process) of each machine has to be set. The strategy is tested with two plant models implemented as Petri net simulations.

Matthias Hüsig

Integrated Operational Techniques for Robotic Batch Manufacturing Systems

Abstract

This paper focuses on a batch manufacturing system with multiple industrial robots. Inappropriate coordination of the robots might cause a bottleneck. In addition, a bottleneck is a constraint that dominates the entire system performance, that is, the productivity. Therefore, for an efficient system, these robots are required to operate appropriately while relating to each other. This is a challenge in this study.We propose the following operational techniques: route planning approaches and operation dispatching rules on the basis of task-assignment that will reduce the effect of a bottleneck. Furthermore, reactive cooperation, so that the robots respond to a fluctuating heavy workload caused by the shifting bottleneck, is an essential operational technique. Throughout the simulation experiments, each combination of the operational techniques is examined; finally, the integrated operational techniques are shown.

Satoshi Hoshino, Hiroya Seki, Yuji Naka, Jun Ota

A Mathematical Model for Cyclic Scheduling with Assembly Tasks and Work-In-Process Minimization

Abstract

In this paper, we deal with the cyclic scheduling problem. More precisely, we consider the cyclic job shop with assembly tasks. Such a problem is made of several jobs, each job consisting of tasks (assembly/disassembly tasks and transformation tasks) being assigned to machines in a cyclic way. This kind of scheduling problem is well fitted to medium and large production demands, since the cyclic behavior can avoid the scheduling of the whole tasks by considering only a small temporal window (cycle). Thus, cyclic scheduling is a heuristic to solve the scheduling problems whose complexity is NP-hard in the general case. Many methods have been proposed to solve the cyclic scheduling problem. Among them, we focus on the mathematical programming approach. We will propose here a mathematical model for cyclic scheduling with assembly tasks and Work-In-Process minimization, and we illustrate this approach with an example from literature.

Mohamed Amin Ben Amar, Hervé Camus, Ouajdi Korbaa

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