CONSTRAINT DEFINITION SYSTEM - A COMPUTER-ALGEBRA BASED APPROACH TO SOLVING GEOMETRIC-CONSTRAINT PROBLEMS

During the computer-aided design of assemblies, or of single objects c omposed of primitive elements, the positions of their constituent part s must be determined. These parts can be positioned absolutely in term s of some coordinate system, or relatively in terms of the relationshi ps or constraints that implicitly exist between their constituents. De spite having many advantages, the latter approach presents computation al problems which have resulted in its limited acceptance. The paper d escribes a system which uses techniques from computer algebra to avoid these problems, and discusses its advantages and disadvantages.