This paper presents an implemented algorithm that automatically de signs fixtures and assembly pallets to hold three-dimensional parts. All fixtures generated by the algorithm employ round side locators, a side clamp, and cylindrical supports; depending on the value of an input-control flag, the fixture may also include swing-arm top clamps. Using these modular elements, the algorithm designs fix tures that rigidly constrain and locate a part, obey task constraints, are robust to part-shape variations, are easy to load, and are eco nomical to produce. For the class of fixtures that are considered, the algorithm is guaranteed to find the global optimum design that sat isfies these and other pragmatic conditions. We present the results of the algorithm applied to several practical manufacturing problems. For these complex problems, the algorithm typically returns initial high-quality fixture designs in less than a minute, and identifies the global optimum design in just over an hour. The algorithm is also capable of solving difficult design problems where a single fixture is desired that can hold either of two parts.
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References
1.
Asada, H., and By, A.B.1985. Kinematic analysis of work-part fixturing for flexible assembly with automatically reconfigurable fixtures. IEEE J. Robot. Automat. RA-1(2):86-94.
2.
Baraff, D., Mattikalli, R., and Khosla, P.1994. Minimal fixturing of frictionless assemblies: Complexity and algorithms. Technical Report CMU-RI-TR-94-08, Robotics Institute, Carnegie Mellon University.
3.
Bausch, J.J., and Youcef-Toumi, K.1990. Kinematic methods for automated fixture reconfiguration planning. Proc. of the IEEE Int. Conf. on Robot. and Automat. Los Alamitos, CA: IEEE , pp. 1396-1401.
4.
Boyes, W.1989. Handbook of Jig and Fixture Design, 2nd ed. Dearborn, Michigan: Society of Manufacturing Engineers.
5.
Brost, R.C., and Goldberg, K.Y.1996. A complete algorithm for designing planar fixtures using modular components. IEEE Trans. Robot. Automat.12(1):31-46.
6.
Brost, R.C., and Peters, R.R.1996. Automatic design of 3-D fixtures and assembly pallets. Proc. of the IEEE Int. Conf. on Robot. and Automat. Washington, DC: IEEE, pp. 495-502.
7.
Brost, R.C., and Peters, R.R.1997. Automatic design of 3-D fixtures and assembly pallets. Technical Report SAND 95-2411, Sandia National Laboratories , Albuquerque, NM.
Chou, Y.-C., Chandru, V., and Barash, M.M.1989. A mathematical approach to automatic configuration of machining fixtures: Analysis and synthesis. ASME J. Eng. Industry111:299-306.
10.
Cohen, P.H.1991. Automated fixture design. National Science Foundation Design and Manufacturing Systems Conf. Dearborn, MI: Society of Manufacturing Engineers, pp. 405-413.
11.
De Meter, E.C.1993. Restraint analysis of assembly work carriers. Robot. Comp. Integrated Manufact.10(4):257-265.
12.
De Meter, E.C.1994. Restraint analysis of fixtures which rely on surface contact . ASME J. Eng. Industry116(2):207-215.
13.
Descotte, Y., and Latombe, J.C.1981. Gari: A problem solver that plans how to machine mechanical parts. Proc. of the 7th Int. Joint Conf. on Art. IntellSan Francisco, CA: Morgan-Kaufman, pp. 766-772.
14.
Englert, P.J.1987. Principles for part setup and workholding in automated manufacturing. PhD thesis, Department of Mechanical Engineering, Carnegie Mellon University.
15.
Ferrari, C., and Canny, J.1992. Planning optimal grasps. Proc. of the IEEE Int. Conf. on Robot. and AutomatLos Alamitos, CA: IEEE, pp. 2290-2295.
16.
Gandhi, M.V., and Thompson, B.S.1986. Automated design of modular fixtures for flexible manufacturing systems. J. Manufact. Sys.5(4):243-252.
17.
Hayes, C.C., and Wright, P.K.1989. Automating process planning: Using feature interactions to guide search. J. Manufact. Sys.8(1):1-15.
18.
Hockenberger, M.J., and De Meter, E.C.1993. Preliminary experimentation and modeling of workpiece displacement during machining. Trans. NAMRI/SME21:351-357.
Kim, K.H.1993. A system for automated fixture planning with modular fixtures . PhD thesis, Robotics Institute, Carnegie Mellon University .
21.
King, L.S., Hart, M., and Wong, D.1991. Geometry and physics of automatic fixture planning for assembly. Proc. of the Int. Conf. on Comp. Integrated Manufact. pp. 525-529.
22.
Lakshminarayana, K.1978. The mechanics of form closure. Technical Report 78-DET-32, American Society of Mechanical Engineers, New York.
23.
Lee, J.D., and Haynes, L.S.1986. Finite-element analysis of flexible fixturing systems. Proc. of the ASME Japan-USA Symp. on Flexible AutomatNew York: ASME, pp. 579-584.
24.
Lozano-Pérez, T., Jones, J.L., Mazer, E., and O'Donnell, P.A.1988. Handey: A task-level robot system. In Bolles, R., and Roth, B. (eds.): Robotics Research: The Fourth International Symposium . Cambridge, MA: MIT Press, pp. 29-36.
25.
Mani, M.1988. Automatic design of workholding fixtures using kinematic constraint synthesis. PhD thesis, Department of Mechanical Engineering, Northwestern University.
26.
Markenscoff, X., Ni, L., and Papadimitriou, C.H.1990. The geometry of grasping . Int. J. Robot. Res.9(1):61-74.
27.
Menassa, R.J., and DeVries, W.R.1989. Locating point synthesis in fixture design. Annals CIRP38(1):165-169.
28.
Menassa, R.J., and DeVries, W.R.1991. Optimization methods applied to selecting support positions in fixture design. Trans. ASME: J. Eng. Industry113(4).
29.
Mishra, B.1991. Workholding: Analysis and planning. Proc. of the IEEE/RSJ Int. Conf. on Intell. Robots and Sys. Los Alamitos, CA : IEEE, pp. 53-57.
30.
Mishra, B., Schwartz, J.T., and Sharir, M.1987. On the existence and synthesis of multifinger positive grips. Algorithmica2(4):641-558.
31.
Nguyen, V.1988. Constructing force-closure grasps. Int. J. Robot. Res.7(3):3-16.
32.
Oberg, E., Jones, F.D., and Horton, H.L.1988. Machinery's Handbook, 23rd ed. New York: Industrial Press.
33.
Ohwovoriole, E.N.1987. Kinematics and friction in grasping by robotic hands. Trans. ASME109.
34.
Overmars, M., Rao, A., Schwarzkopf, O., and Wentnik, C.1995. Immobilizing polygons against a wall. ACM Symp. on Computational Geometry. New York: ACM, pp. 29-38.
35.
Pertin-Troccaz, J.1989. Grasping: A state of the art. In Khatib, O., Craig, J. J., and Lozano-Pérez, T. (eds.): The Robotics Review I. Cambridge, MA: MIT Press, pp. 71-98.
36.
Ponce, J.1996. On planning immobilizing fixtures for three-dimensional parts. Proc. of the IEEE Int. Conf. on Robot. and AutomatWashington, DC: IEEE, pp. 509-514.
37.
Ponce, J., Sullivan, S., Boissonnat, J., and Merlet, J.1993. On characterizing and computing three- and four-finger force-closure grasps of polyhedral objects. Proc. of the IEEE Int. Conf. on Robot. and AutomatLos Alamitos, CA: IEEE, pp.821-827.
38.
Quinter, K.1993. Qu-Co modular fixturing system. Union, Ohio: Qu-Co, Inc.
39.
Rearick, M.R., Hu, J.S., and Wu, S.M.1993. Optimal fixture design for deformable sheet-metal workpieces . Trans. NAMRI/SME21:407-412.
40.
Reuleaux, F.1876. The Kinematics of Machinery. New York : Macmillan. (Republished in 1963 ; New York: Dover.)
41.
Sakurai, H.1992. Automatic setup planning and fixture design for machining . J. Manufact. Sys.11(1):30-37.
42.
Salisbury, J.K., and Craig, J.J.1982. Articulated hands: Force control and kinematic issues . Int. J. Robot. Res.1(1):4-17.
43.
Shirinzadeh, B.1993. Issues in the design of the reconfigurable fixture modules for robotic assembly. J. Manufact. Sys.12(1):1-14.
44.
Trinkle, J.C.1992. A quantitative test for form-closure grasps. Proc. of the IEEE/RSJ Int. Conf. on Intell. Robots and SysLos Alamitos, CA: IEEE, pp. 1670-1677.
45.
Wagner, R., Zhuang, Y., and Goldberg, K.Y.1995. Fixturing faceted parts with seven modular struts. Proc. of the IEEE Int. Symp. on Assembly and Task PlanningWashington, DC: IEEE, pp. 133-139.
46.
Wallack, A.S., and Canny, J.F.1994. Planning for modular and hybrid fixtures. Proc. of the IEEE Int. Conf. on Robot. and AutomatWashington, DC: IEEE, pp. 520-527.
47.
Wallack, A.S., and Canny, J.F.1996. Modular fixture design for generalized polyhedra. Proc. of the IEEE Int. Conf. on Robot. and AutomatWashington, DC: IEEE, pp. 830-837.
48.
Wentink, C., van der Stappen, A.F., and Overmars, M.1996. Fixture planning. In Laumond, J.-P., and Overmars, M. (eds.): The Algorithmic Foundations of Robotics. Boston, MA: A. K. Peters.
49.
Wolter, J.D., and Trinkle, J.C.1994. Automatic selection of fixture points for frictionless assemblies. Proc. of the IEEE Int. Conf. on Robot. and AutomatWashington, DC: IEEE, pp. 528-534.
50.
Yu, K., and Goldberg, K.Y.1995. Fixture loading with sensor-based motion plans. Proc. of the IEEE Int. Symp. on Assembly and Task PlanningWashington, DC: IEEE, pp.362-367.
51.
Zhuang, Y., Goldberg, K.Y., and Wong, Y.1994. On the existence of modular fixtures. Proc. of the IEEE Int. Conf. on Robot. and AutomatWashington, DC: IEEE.
