Angular momentum based balance controller for an under-actuated planar robot

In this paper, a new control algorithm based on angular momentum is presented for balancing an under-actuated planar robot. The controller is able to stabilize the robot in any unstable balanced configuration in which the robot is controllable, and also it is able to follow a class of arbitrary trajectories without losing balance. Simulation results show the good performance of the controller in balancing and trajectory tracking motions of the robot. The simulations also show that the proposed controller is robust to significant imperfections in the system, such as errors in the controller’s dynamic model of the robot and imperfections in the sensors and actuators. The new controller is compared with three existing balance controllers and is shown to equal or outperform them.