Turning maneuvers and mediolateral reaction forces in a quadruped robot

In this paper we address the turning maneuver technique for a quadruped robot with only the hip pitch and the knee pitch for each leg, and explore characteristics of the mediolateral reaction forces experienced by the robot legs during the stance phase. We propose a turning strategy based on the translation of the hip-knee joint space towards the deepest flexion point. Such a translation can cause the robot body inclination in the roll plane, and consequently, result in the changes of the mediolateral reaction forces. In particular, we investigate the mediolateral reaction forces during straight walking and turning. Simulation results reveal that the lateral and medial reaction forces during turning differ strongly from those during straight walking in terms of the frequency used and peak force magnitude. That is, the dominance of the lateral or medial reaction forces in frequency and magnitude contributes forces and torques requisite for the turning maneuver.