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

Abstract

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 spinning flywheel acts as a gyroscope to stabilize the robot and it can be tilted to achieve steering. Its nature is nonholonomic, underactuated and inherently unstable in the lateral direction. In this paper, we discuss the problem of controlling the tilt-up motion of such a dynamically stable but statically unstable robot. We first present a dynamic model which is verified through simulations and experiments. Then, we develop a model-based controller for tilt-up motion, assuming that the robot is rolling without slipping. 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 control strategy model to abstract the operator’s skill in controlling the tilt-up motion. The controller was successfully implemented, such that the robot can recover from fall automatically. This work is a significant step towards a fully automatic control of such a dynamically stable but statically unstable robot.