Control Based on Swing Up and Balancing Scheme for an Underactuated System, with Gravity and Friction Compensator

This paper proposes a control scheme for underactuated two-link robot called the pendubot. The controller achives to swing, and stabilize to its uppermost unstable equilibrium point, the second non-attracted link. The control law is designed and the convergence analysis is carried out based on Lyapunov stability theory. Swinging control is based on an kinetic energy approach and the passivity properties, and then some conditions on the parameters in the control law such that the error of the first link converges to zero, i.e. top upright position of pendubot. The stabilization system is based on switching LQR control.