Comparison of a planar parallel manipulator architectures based on a multi-objective design optimization approach

Damien Chablat, Stephane Caro, Raza Ur-Rehman, Philippe Wenger (Institut de Recherche en Communications et Cybern´etique de Nantes)

The manipulator architectures are compared with regard to their mass in motion and their regular workspace size, i.e., the objective functions. The optimization problem is subject to constraints on the manipulator dexterity and stiffness.
For a given external wrench, the displacements of the moving platform have to be smaller than given values throughout the obtained maximum regular dexterous workspace. The contributions of the paper are highlighted with the study of 3-PRR, 3-RPR and 3-RRR planar parallel manipulator architectures, which are compared by means of their Pareto frontiers obtained with a genetic algorithm.

The multi-objective optimization problem has been solved by means of modeFRONTIER and by using its built-in multi-objective optimization algorithms. The proposed approach has been applied to the optimum design of three planar parallel manipulators with the aim to minimize the mass in motion of the mechanism and to maximize its regular shaped workspace.