Integral sliding Mode Control of a bipedal Leap

This paper examines the dynamics and control of the humanoid double support stance (DSS) leap in the air and the subsequent stable landing. A complete model of a five-link biped standing on flat ground is considered in four phases: the take-off phase, the flight phase, the landing phase with impact, and the standing-up phase. Based on the presented dynamic formulation, an integral sliding mode control strategy is developed to track the reference motion, obtained by experimental recording of humans executing the DSS leap. The stability, finite-time convergence and robustness of the system are analyzed, and verified by computer simulation. The predicted ground reaction force (GRF) profiles are in agreement with experimental recording of the GRFs. In particular, the predictions capture the short duration, and large amplitudes of the GRFs upon impact as well as the burst of high energy required during the take-off phase.