Speed Control of Quadrupedal Bounding Using a Reaction Wheel

Abstract — To date, quadruped speed control has either been achieved with two actuators per leg, or with single actuators and time consuming trial and error experimentation for controller tuning. In this paper, a novel control method is developed that uses only one actuator per leg and yet requires no controller tuning from the user, since the control parameters are computed through analytical expressions derived from the robot dynamics. One further actuator is used to drive a reaction wheel situated on the body. The control method leads to stable bounding gaits with controllable forward speed, and as the control is based on analytical results from the robot dynamics, it is applicable to a range of design parameters, rather than a specific robot. Light, off-the-shelf DC motors are shown to be adequate for successful controller operation. Results are shown of the control applied to a detailed robot model, including leg and toe mass, foot collision, DC motor model, joint friction and a foot-ground friction model allowing foot slipping. Index Terms — speed control, quadruped robot, bounding