The traditional techniques of synthesis of mechanisms are still limited from application and performances point of view. The experiment of the designer still the essential talent to solve this kind of problem. For this purpose, we propos e to develop tools for synthesis of plane and spatial mechanisms and parallel robots by an evolutionary method. The first part is interested in the synthesis of the plane and spatial mechanisms. The new suggested modeling uses the Denavit-Hartenbe rg parameter. This parameter setting makes easily and possible the study of the four families of mechanisms that we identified. They are solved by an optimization technique based on a combine between a ge netic algorithm and a fuzzy logic controller. An app lication of a spatial mechanism is also developed, which we proposed, like anti pressure ulcers device. The second part is dedicated to the analysis and the dimensional sy nthesis of the DELTA robot for a prescribed workspace. We introduce the concept of power of a point compared to a surface, used in the formulation of the problem of synthesis. In fact, this approach rests on a process of optimization genetic adapting to the various criteria of synthesis.
