Mobility and agility analysis of walking robot

Abstract

This paper presents a mathematical framework for mobility and agility analysis of multi-legged walking robots. The method is acceleration analysis in consideration of the frictional ground contact. This method is based on both unified dynamic equation for finding the acceleration of a robot’s body and cosntraint equation for satisfying no-slip condition. After the dynamic equation representing relationship between actuator torques and body acceleration, is derived from the force and acceleration relationship between foot and body’s gravity center, the constraint equation if formulated to reconfigure the maximum torque boundaries satisfying non-slip condition from given original actuator torque boundaries. From application of the reconfigured torques to the dynamic equation, interested acceleration boundaries are obtained. The approach based on above tow equations, is adapted to the changes of degree-of-freedoms of legs as well as friction of ground. And, the method provides the maximum translational and rotational acceleration boundaries of body’s center that ar achievable in every direction without ocurring slipping at the contact points or saturating all actuators. Given the torque limits in infinite norm-sense, the resultant accelerations are derived as a polytope. From the propose method, we obtained achievable acceleration boundaries of 4-legged and 6-legged walking robot system successfully.