Nonlinear feedforward and feedback tracking control with input constraints solving the pendubot swing-up problem
Abstract
The swing-up maneuver of a pendubot is accomplished by a tracking control with separate design of a nonlinear feedforward and a linear feedback part. The inversion-based feedforward control treats the swing-up as a nonlinear two-point boundary value problem with input constraints in the coordinates of the input-output normal form and is numerically computed by a standard Matlab function. The feedback part with time-variant gains is designed as an LQR controller for the pendubot model linearized along the nominal trajectories. The tracking control is validated in experimental swing-up maneuvers of the pendubot.