Fast and Adaptive Hopping Height Control of Single-Legged Robot

Abstract

Research on running robots has generally focussed on the steady-state. When the ground has limited foot placement surfaces or there are sudden changes in height then steady-state running is not possible. It becomes necessary to make step-by-step adjustments to place the foot. In this paper a mass-spring-damper model of a robot’s leg is used to develop a hopping controller capable of meeting rapid changes in demand height or flight time. Analysis of the model provides a simple method to select control parameters for effective height control without tuning or iteration. Additionally, a simple adaptive algorithm is introduced and demonstrated in simulation. The adaptive control algorithm allows rapid changes of height even when ground characteristics change. Experimental validation is ongoing and some preliminary results are provided.