A Wheelchair Type Mobile Robot Taking Environmental Disturbance into Account Based on Compliance Control

Abstract

Both human and robot will carry out a task which is not realizable by only each of them. In particular, human recognizes environment and reflects to trajectory planning well. On the other hand, robot generates the controlled force more than human. In this paper, the best combination of human ability and robot capacity is considered. Commands of human by a joy stick are changed into the virtual force commands instead of position commands. Thereby, a soft robot is able to be realized. When it collides with an obstacle, it controls softly to external force in order to relax the shock. This is realizable by applying compliance control to the human input and external force. Reaction force estimation observer is implemented in robot to detect environmental disturbance. Environmental disturbance is classified into the mode of translational direction and rotational direction. By identifying environmental friction coefficient and changing gain of a joy stick, when a passenger and a road surface situation change, the desired operation characteristic is achieved. The proposed method is applied to wheelchair. As a result, operationality and ride quality are improved.The experimental results show viability of the proposed method.