Dynamic Walking 2010. Jerry Pratt. Humanoid Disturbance Recovery with Limited Available Footholds
We present a method for controlling humanoid robots to recover from disturbances when available footholds are limited. This method involves determining the robot's Capture Region taking into consideration the available footholds, deciding where in the Capture Region to step to, and guiding the robot during stance so that the desired location to step to stays inside the Capture Region. We show how to estimate the Capture Region by using a Linear Inverted Pendulum model of walking. With this model, the dynamics of the Instantaneous Capture Point are first order and linear. Therefore, the Capture Region can be constructed using fairly simple and fast 2D overhead geometry constructions techniques. We demonstrate this technique for a simulated model of the robot M2V2 crossing stepping stones in the presence of pushes.