Optimal Design of Parallel Mechanism for Automobile Electro-Coating Conveyor

Abstract

Poor mechanism rigidity are prone to big terminal deformation as one exerts certain external force. In order to make the terminal deformation within acceptable range, work space needs to be optimized first with suitable global rigidity evaluation index. For the purpose, Global Stiffness Index (GSI), is defined in the paper. Dimensionless work space of the parallel mechanism is optimized based on the GSI, combined with the Upper Limit of the Jacobian matrix condition number and Maximum Tolerated Deformation. Within the dimensionless work space, terminal deformation does not exceed tolerated value, at the same time, the level of average deformation can reach average requirement. Link length, a parameter of the parallel mechanism, is later obtained with real length of work space divided by the dimensionless length of work space. Optimal design results are computed according to specific design requirements to the parallel mechanism in the automobile electro-coating conveyor. The simulation verifications show that the optimal design to parallel mechanism is in accord with design requirements. The design results are also used to develop a prototype for further research.