Motion Control of a Bipedal Walking Robot

This paper investigates the performance of different control schemes applied on a 5-link biped robot by simulation studies. The primary controller are implemented with a conventional Proportional Derivative (PD) controller and Computed Torque controller, later enhanced with Active Force Control (AFC). The mathematical modeling and motion control for a bipedal walking robot in this paper consisted of five links, which includes torso, two thighs and two legs. The joints connecting these links are assumed to be friction free and driven by independent servo motors. Reference trajectory for each joint are plotted and designed to produce a five steps gait on horizontal plane with constraint to sagittal plane. Kinematic and dynamic modelling are derived for motion controller to achieve dynamic walking. An animation of bipedal walking robot is simulated using MATLAB Simulink to visualize the bipedal locomotion. By default, proportional and derivative (PD) and computed torque control schemes are implemented into the dynamic model of the five degree of freedom bipedal robot for motion control. The control scheme is further implemented with Active Force Control strategy. The performance of the control schemes are evaluated to determine the control system that can produce optimum performance. It is found that AFC integration on the default controller resulted a robust and stable control system. Key-Words: biped robot, active force control, neural network, computed torque.