Using Zero Moment Point preview control formulation to generate nonlinear trajectories of walking patterns on humanoid robots

Generating nonlinear trajectories of walking patterns is one of the most important problems in stability a humanoid robot when it walks on different ground conditions. In order to solve this problem, a desired Zero Moment Point (ZMP) trajectory is firstly designed and then a Center of Mass (CoM) trajectory will be created based on this ZMP. Hence, the preview control formulation which follows the planned ZMP patterns while reducing the jerk (acceleration derivation) is considered to implement this trajectory. In this study, the walking pattern for bipedal robot is generated by using a cart-table model. The procedure of apply a preview controller to the cart-table model will be presented in this investigation. After that, the position of each leg joint of bipedal robot is also calculated by using the proposed CoM Jacobian. Finally, computer simulations are performed by utilizing RecurDyn and MATLAB softwares to validate the proposed preview control formulation for the nonlinear walking patterns generation of a Bioloid humanoid robot.