Generating smooth trajectories free from overshoot for humanoid robot walking pattern replanning

Abstract

In the field of humanoid robotics, developing a walking system capable of adapting to new situations is driven by the prospect of employing humanoid robots in unknown environments. By evaluating sensor data, the control system may acquire information about the environment and utilize that information for adaptation. In this paper, we focus on the reaction of a control system when encountering an earlier than expected ground contact of the swing leg. A method of planning a -continuous foot trajectory is presented. The boundary conditions of that trajectory are defined by position, velocity and acceleration of the originally planned trajectory at the time of replanning and a prescribed position that is reached after an arbitrarily chosen time interval with zero velocity and acceleration. We require this trajectory to be -continuous and free from overshoot. The function we propose contains a parameter utilized for optimization and to prevent overshoot. We show that the global optimum of our acceleration-based objective function can be obtained analytically. © 2012 Springer-Verlag Berlin Heidelberg.