Multi-body dynamics simulation and gait pattern analysis of a bio-inspired quadruped robot for unstructured terrains using adaptive stroke length

This paper presents the Finite element analysis (FEA), Multi-body dynamics (MBD) simulation and gait pattern analysis of a bio-inspired quadruped robot. A novel power transmission mechanism with varying gear train centre distance has been designed for generating different gait structures to suit unstructured terrain. The adjustable length of the lower link aids in improving the stability of the robot (or) make the robot to travel longer distances within a stipulated time. MBD simulation has been performed using MSC/ADAMS for torque, speed, energy and force analysis. The novel mechanism designed was able to successfully negotiate unstructured obstacles of different heights and these results have been presented in the paper. The results show a direct relationship between stroke length, lift-off distance and gear centre distance. A full scale experimental setup, along with the suitable supporting mechanisms is developed. The experimental analysis has been carried out for measuring the Ground Reaction Force (GRF). The GRF is found to be 45 N on an average, when the robot is walking.