Effects of stride length and frequency on mobile performance of a hydraulic hexapod robot

Gait parameters play a significant role in the locomotion of a hexapod walking robot used for different goals. Stride length and frequency are the two most important and useful gait parameters of hexapod robots. This paper presents the configuration of a hydraulic hexapod walking robot. The typical gaits of hexapod robot are introduced and the kinematic model of the robot is established. Four performance metrics to evaluate the mobility performance of the hexapod robot are chosen and analyzed, and they are maximum foot force, maximum actuation cylinder force, maximum power and maximum flow. Prototype of the hydraulic hexapod robot is developed, and four performance metrics are measured according to a series of walking experiments of the robot prototype under different stride length and frequency. The influences of stride length and walking frequency on mobility performance of the hexapod robot are studied. It can be found that the foot force, cylinder force, power and flow consumption increase with the increase of stride length and walking frequency. The findings of this paper can be applied for the motion planning and control of legged robots.