Control of tilt-up motion of a single wheel robot via model-based and human-based controllers

A single wheel, gyroscopically stabilized robot was developed to provide a dynamic stability for rapid locomotion. It is a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The s pinning flywheel acts as a gyroscope to stabilize the robot and it can be t ilted to achieve steering. Its nature is nonholonomic, underactuated and in herently unstable in the lateral direction. In this paper, we discuss the p roblem of controlling the tilt-up motion of such a dynamically stable but s tatically unstable robot. We first present a dynamic model which is verifie d through simulations and experiments. Then, we develop a model-based contr oller for tilt-up motion, assuming that the robot is rolling without slippi ng. Taking advantage of human skill in teleoperating the robot, we develop a human-based controller for tilt-up motion, in which we train a human cont rol strategy model to abstract the operator's skill in controlling the tilt -up motion. The controller was successfully implemented. such that the robo t can recover from fall automatically. This work is a significant step towa rds a fully automatic control of such a dynamically stable but statically u nstable robot. (C) 2000 Elsevier Science Ltd. All rights reserved.