Kinematics Synthesis Of Planar Multi-Loop Linkage Mechanisms For Multiple Tasks Purposes.

Abstract

The essence of mechanism synthesis is to find the mechanism for a given motion or task.
There are three customary tasks for kinematic synthesis: path following, rigid-body guidance, and function
generation. However, two or more of these tasks may be required to be performed for different
bodies of the same mechanism. In this paper, we present a fairly general method to solve the kinematics
synthesis problem for multiple tasks. In order to apply analytical synthesis equations, the task is
discretized by a number of prescribed displacements and orientations called “passing points”. A Finite
Element and Graph Theory representation of mechanisms is used to represent the prescribed motion
constraints on the parts of the problem. Also, Graph and combinatorial algorithms are used to solve the
type synthesis problem listing a discrete number of feasible non-isomorphic topologies. Then, for each
feasible topology, a multi-objective optimization based on a Genetic Algorithm –zero order search– is
run to find the initial dimensions and pivot positions of the unknown parts of the linkage.
Computer implementation of this method were programmed in C++ language under the Oofelie environment
and was presented in previous AMCA congresses. The aim of this paper is to incorporate
new data and modify the existing algorithms to take into account multiple tasks. A double task which
combines a path following and a rigid-body guidance problem will be presented throughout the paper.