Modified Transpose Jacobian control of a biped robot

Designing smooth and stable trajectories for control of the biped robots is a challenging problem that is the focus of this article. A desired trajectory for the lower body will be designed to alleviate the impacts due to contact with the ground. This is obtained by fitting proper polynomials at appropriate break points. Then, planning the upper body motion is accomplished based on the zero moment point (ZMP) criterion to provide a stable motion for the biped robot. Next, a non-model-based controller called modified transpose Jacobian (MTJ) algorithm will be used to control the biped robot for tracking the planned trajectory. The MTJ algorithm, based on an approximated feedback linearization approach, employs stored data of the control command in the previous time step, to yield an improved performance. Obtained results show that the performance of the proposed MTJ controller is comparable to perfect model based controllers, even with unexpected disturbances.