Hybrid Motion Control of Humanoid Robot for Leader-Follower Cooperative Tasks

Journal Paper

S. Savić; M. Raković; B. Borovac; M. Nikolić

Thermal Science

2016

vol. 20(2) , pp. 549-561

Abstract

This paper presents a framework for leader-follower type cooperative transportation of an object by multiple humanoid robots or a single robot and a human. The emphasis in this paper is on the hybrid control algorithm and motion generation of the follower robot, while the influence of the leader has been simulated as external force acting on the follower’s hands. The presented approach uses impedance controller to provide compliant behavior of robot arms and it is an extension of our previous work on dual-mode impedance controller for safe human-robot interaction. Synthesis of the follower’s legs and trunk motion is based on the reconfigurable adaptive motion primitives, which are defined as simple, parameterized motion building blocks that can be combined in a sequence or in parallel to generate complex motion. It has been already proven that motion generation, based on reconfigurable adaptive primitives enables the robot to modify gait parameters online, at any time instant, and to synthesize dynamically balanced walk. Motion of the follower is based on the reactive approach, where the gait parameters (walking velocity, direction and step length) depend on the intensity and the direction of the external force vector. Robot end-effectors are compliant in the horizontal plain, adapting to the physical guidance of the leader, while being stiff in the vertical direction in order to compensate the external force in negative Z direction. The proposed framework has been tested by numerical simulations involving a dynamic robot model. [Projekat Ministarstva nauke Republike Srbije, br. III44008 and by Provincial secretariat for science and technological development under contract 114-451-2116/2011]