Motion Coordination between a Human and a Robotic Wheelchair in a Crowded, Public Environment

In this paper we describe an approach to coordinating the motion of a human with a mobile robot moving in a populated, continuously changing, natural environment. Our test application is a wheelchair accompanying a person through the concourse of a railway station moving side by side with the person. In healthcare and rehabilitation scenarios this addresses a rather important issue. Pushing and maneuvering a carriage such as a wheelchair or a hospital bed, exposes the back of the pushing person to extreme significant often resulting in severe long-term back problems. Our approach is based on a method for motion planning amongst moving obstacles known as Velocity Obstacle approach. We extend this method by a method for tracking a virtual target which allows us to vary the robot's heading and velocity with the locomotion of the accompanied person and the state of the surrounding environment.