( L ) On The Motion of Compliantly-Connected Rigid Bodies in Contact , Part II : A System for Analyzing Designs for Assembly

, The design of mechanical devices and the planning to assemble them should not be independent activities. -We--i#du6 a new, fully algorithmic, combinatorially precise approach to designing devices so that they are easy to assemble and (optionally) hard to disassemble. Owy analysis can be used to validate good designs, and can be iterated to generate improved designs. The approach is based on an algorithm for predicting the motion of flexible objects in contact; the flexible objects have rotationally passively compliant members, which deform when theyexperience contact forces from the environment. Such objects are intended to model -"snap-fastener'-type devices, which are very useful in design for assembly. ., _t), g I. The algorithm is based on the theory in ew -eempahon paper-IPD89f; idthis paper 9 -we-describe;the details of the algorithm, its implementation in a system for predicting and avalyzing the motion of snap-fastener-type devices, and experiments we ran using the sy.,tem to analyze and design particular devices. I J *This paper describes research done in the Computer Science Robotics Laboratory at Cornell University. Support for our robotics research is provided in part by the National Science Foundation under grant No. IRI-8802390 and by a Presidential Young Investigator award, and in part by the Mathematical Sciences Institute. tSupported in part by DARPA grant N0014-88-K-0591, MSI grant U03-8300, iSF grant DMC-86-17355, and by ONP. grant N00014-86-K-0281. Lw..~~~~ -;I8 f Y 14