Walking control algorithm of the 5-link robot based on operational space control

This paper presents the control strategy for 5-link biped robot consisting of an underactuated floating trunk and rigid legs. Controlling legged system is challenging due to the underactuated floating bases and the dynamic changes of contact states. Our main contributions are as follows: 1) formulating the desired end-effector force for achieving the balance of trunk while walking and 2) applying the operational space control(OSC) to the walking model which is constrained and underactuated. Overall, we present the dynamical simulation under random initial state and the force disturbances to validate the performance of control strategy, regarding stabilizing the floating trunk and maintaining the walking gait.