Compliance/Impedance Control Strategy for Humanoids

Abstract

Compliance/impedance control is an important control method in dealing with uncertainties. This chapter explains how compliance/impedance control can be used in humanoid robots in adapting to ground uncertainties. First, compli- ance/impedance control is explained in the general context of robotics. Then, typical structures for controllers for impedance control and admittance control are also explained. What is impedance for a humanoid robot in locomotion and running is defined and how impedance control, as a superset of compliance control, is applied as it is described. The legs of a humanoid robot in locomotion and running go through many different phases. A human in locomotion and running changes the tension of his/her leg muscles. In order to deal with many different phases of the legs, it is critical to modulate the impedance parameters depending on the phases, as a human does in his or her locomotion and running. This chapter also describes how the impedance parameters can be modulated in control for a humanoid robot for successful locomotion and running.