Balance Control for a Class of Underactuated Systems via Compensation Signals

As a typical underactuated experimental platform for robotics and control theory, the rotary inverted pendulum (RIP) system is nonlinear, multi-variable, and strongly coupled. We study the swing-up and balance control for the RIP system with system uncertainty. The classical energy-based swing-up control without compensation for the uncertainty and the signal compensation-based balance control are adopted. In the balance control, from the linearized state-space model near the upright equilibrium point (UEP) and the estimated discrete-time model, a signal compensation-based balance control is constructed to eliminate and suppress the system uncertainty. Simulation results verify the effectiveness of the controllers.