Although parallel-jaw grippers play a vital role in automated manufacturing, gripper surfaces are still designed by trialand-error. This paper presents an algorithmic approach to designing gripper jaws that mechanically align parts in the vertical (gravitational) plane. We consider optimal edge contacts, based on modular trapezoidal segments that maximize contact between the gripper and the part at its desired final orientation. Given the n-sided 2D projection of an extruded convex polygonal part, mechanical properties such as friction and center of mass, and initial and desired final orientations, we present an O(n 3 log n) numerical algorithm to design optimal gripper jaws. We also present an O(n log n) algorithm to compute tolerance classes for these jaws, and report on an online implemented version of the algorithm and physical experiments with the jaws it designed. This paper extends earlier results that generated optimal point contacts [M. T. Zhang and K. Goldberg, "Gripper point contacts for part alignment," IEEE Trans. Robot. Autom. 18(6), 902-910 (2002)].
interdisciplinary decision making, model uncertainty and learning, production systems modeling and analysis, queueing theory, reliability, scheduling, semiconductor yield management, simulation, stochastic processes, and supply chain management. He has written or written jointly over 250 papers on these topics. His book Stochastic Models of Manufacturing Systems with John Buzacott was the runner for the 1993 ORSA Lanchester Price (received an honorable mention). He is (or was) a member of the editorial boards of the . His research mainly concerns the development of better modeling and analytical methods (MCDM, OR, and statistics) and solutions (implemented in terms of IT) for high-tech companies confronted with decision problems involved in operations, technology, and manufacturing strategies that are characterized by uncertain (incomplete or massive) information and a need for tradeoff among various objectives and justification for the decisions. He has received four invention patents on semiconductor manufacturing methodologies. He has published more than 70 journal papers and served as guest editors for journals including OR Spectrum, and the International Journal of Production Economics, Computers and Industrial Engineering.Dr.
Industrial parts can be fed (oriented) using a sequence of fixed horizontal pins to topple the parts as they move past on a conveyor belt. We give an algorithm for designing a sequence of such pins for a given part. Given the n-sided convex polygonal projection of a part, its center of mass and frictional coefficients, our O(n2) algorithm computes the toppling graph, a new data structure that explicitly represents the mechanics of toppling, rolling, and jamming. We verify the toppling graph analysis with experiments. Our O(n3n) design algorithm uses the toppling graph to design a sequence of pin locations that will cause the part to emerge in a unique orientation or to determine that no such sequence exists.
About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -Semiconductor manufacturing industry requires highly accurate robot operation with short install/setup downtime. Design/methodology/approach -We develop a fast, low cost and easy-to-operate calibration system for wafer-handling robots. The system is defined by a fixture and a simple compensation algorithm. Given robot repeatability, end effector uncertainties, and the tolerance requirements of wafer placement points, we derive fixture design and placement specifications based on a statistical tolerance model. Findings -By employing the fixture-based calibration, we successfully relax the tolerance requirement of the end effector by 20 times. Originality/value -Semiconductor manufacturing requires fast and easy-to-operate calibration systems for wafer-handling robots. In this paper, we describe a new methodology to solve this problem using fixtures. We develop fixture design criteria and a simple compensate algorithm to satisfy calibration requirements. We also verify our approach by a physical example.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.