Optimization design of a bionic horse’s leg system driven by a cam-linkage mechanism

Abstract

For equine-assisted therapy, a bionic horse configuration is presented. A bionic horse’s single leg system has two degrees of freedom (DOFs), which is driven by a cam-linkage mechanism and can adjust the leg’s endpoint trajectory. Based on analyzing the motion law of the bionic horse and the foot trajectory’s requirements of the leg system, a multi-objective optimization model is established based on the foot trajectory performance index. To determine the objective function, the errors between the ideal foot trajectory and the mechanism motion model’s foot trajectory, and the errors between the actual adjustable values and the target values for the motion range are taken as the optimization objective. In terms of the constraint conditions, the structural constraints, kinematic feasible region conditions, pressure angle requirements, et al., are considered. The ideal mechanism parameters are obtained by the intelligent optimization method. The results are verified by simulation modeling and experimental prototype, and the relevant ideas can provide a reference for the research of similar problems.