KINEMATICS SYNTHESIS OF PLANAR MULTI-LOOP LINKAGE MECHANISMS FOR MULTIPLE TASKS PURPOSES

MARTÍN PUCHETA; ALBERTO CARDONA

Cordoba

Congreso; XVI Congreso sobre Metodos Numericos y sus Aplicaciones ENIEF 2007; 2007

Asociación Argentina de Mecánica Computacional

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.