Parts feeding and parts presentation

Citation

Tao Zhang, M. (2006), "Parts feeding and parts presentation", Assembly Automation, Vol. 26 No. 3. https://doi.org/10.1108/aa.2006.03326caa.002

Parts feeding and parts presentation

Parts feeding and parts presentation

Part feeding aims to sort and orient industrial parts before assembly, which is essential to industrial automation and flexible assembly. Excellent surveys can be found in Nevins and Whitney (1978) and Boothroyd et al. (1982).

A traditional part feeding device is vibratory bowl feeders (Lim et al., 1994; Maul and Thomas, 1997). These devices are particularly designed for a small number of parts based on their geometric and physical properties. Caine (1994) represented part interactions as motion constraints in configuration space, and developed a set of computational tools to design vibratory bowl feeder tracks. Christiansen et al. (1996) applied genetic algorithms to the design of vibratory feeder tracks. Berretty et al. (2001) studied and proposed algorithms to decide whether or not the part in a specific orientation will fall into a trap under gravity. Holes of various shapes were cut in a bowl feeder track so that the parts in undesired orientations would fall back to the bowl. Despite the widespread use of the bowl feeders, their design is still a black art that is responsible for up to 30 per cent of the cost and 50 per cent of workcell failures (Nevins and Whitney, 1978; Boothroyd et al., 1982).

One of the earliest theoretic studies on part feeding is introduced by Erdmann and Mason (1988). They developed a systematic algorithm for sensorless manipulation to orient parts, using a tilting tray.

Extensive research focuses on part feeding by grasping. Goldberg (1993) demonstrated that a sequence of normal pushes/grasps can orient polygons up to symmetry. Rao et al. (1996) proposed a flexible part feeding system that takes advantage of pivoting grasp: when a part is grasped with two hard finger contacts and lifted, it pivots under gravity into a stable configuration. They proved that a robot arm with four degrees of freedom (DOF) can move (feed) parts arbitrarily in six DOF using pivot grasps. Zhang and Goldberg (2002) showed that it is possible to align parts during grasping using a standard parallel-jaw gripper. One solution is an arrangement of four gripper point contacts that align the part in the vertical plane as the jaws close.

Conveyor belts with rigid fences were initially analysed by Peshkin and Sanderson (1998), who developed a numeric search algorithm to find a sequence of passive fences to orient parts based on configuration space analysis. Wiegley et al. (1997) gave a complete algorithm to compute the shortest sequence of frictionless curved fences. Gudmundsson and Goldberg (1999) derived the optimal belt velocity of a part feeder based upon a 1D Poisson process model. They also outlined how feeder throughput can be estimated based on estimates of conveyor speed. Similar feeder designs are described in Causey and Quinn (1997) and Wolfson and Gordon (1997). Akella et al. (2000) considered a minimalist manipulation method to feed planar parts using a one joint robot over a conveyor belt. Zhang et al. (2001) studied a sensorless approach to feeding parts on a conveyor belt using pins (rigid barriers) to topple parts into desired orientations. They developed a new data structure that represents the mechanics of toppling including rolling and jamming. They also presented a complete algorithm for designing pin sequences.

Some innovative part feeding methodologies have been developed recently, especially for Micro Electro Mechanical Systems (MEMS). Joffe (1991) pioneered in applying magnetic fields to orient and assemble ferromagnetic parts. Böhringer et al. (2000) proved the existence of a programmable force field that can bring arbitrary (nonsymmetric) parts into exactly one or two stable equilibriums. This result could lead to a new generation of efficient parts feeders.

Finally, we would like to thank all of the authors and the anonymous reviewers for their outstanding works.

Mike Tao Zhang received the Management of Technology certificate (2000) from the Haas School of Business, the MS (2000) and the PhD (2001) degrees from the Department of Industrial Engineering and Operations Research all at the University of California, Berkeley, USA in three years. He is currently a Staff Engineer at Intel Corporation in Arizona, USA. He has been a Senior Engineer, a Group Leader, and a Department Manager at various Intel sites. He was awarded two patents and published about 50 papers and three books/book chapters. His research interests are industrial automation, manufacturing systems, operations research/management, and supply chain management. Zhang is a Member of the Honor Society of Phi Kappa Phi, and also a Senior Member of IEEE and the Institute of Industrial Engineers (IIE). He is the Co-Chair of the IEEE Robotics and Automation Society Technical Committee on Semiconductor Factory Automation. He is an Associate Editor of the IEEE Transactions on Automation Science and Engineering and a Guest Editor of Assembly Automation, the IEEE Robotics and Automation Magazine, and the IEEE Transactions on Automation Science and Engineering. He is the recipient of the Intel ATM Achievement Award, the IIE Outstanding Young Industrial Engineer Award, and the IEEE RAS Early Career Award in Robotics and Automation.

Mike Tao Zhang Based at the Intel Corporation, Chandler, Arizona, USA