A Topology Optimization Method for Robot Light-Weight Design under Multi-Working Conditions and Its Application on Upper-Limb Powered Exoskeleton

The existing topology optimization for robot lightweight design is carried out under a given extreme working pose (ie, working con-dition) when doing the finite element analysis (FEA). As the working pose of the robot is time-varying, the results with this method may not satisfy all the working conditions of the robot. In this paper, a new topology optimization method under mul-ti-working conditions(MWC) is proposed for robot lightweight design. First, the different typical working conditions are selected according to the application situations of the robot, and then the final extreme working conditions for optimization are obtained by using of FEA method. Next, the structure of the parts is rede-signed with topology optimization method based on the extreme working conditions by the constraints of maximum end dis-placement and the goal of minimized mass. Then, the method is applied to the lightweight design of a 5 DOF upper-limb powered exoskeleton. The result shows that this method can reduce 9.92% maximum stress compared to the existing one. It is concluded that the proposed method in this paper is suitable for the light-weight design of the robot with time-varying pose.