Composite Nonlinear Feedback Control for Inverted Pendulum with Input Saturation

In this paper, we develop and implement Composite Nonlinear Feedback (CNF) control law for an inverted pendulum subject to actuator saturation. The inverted pendulum mounted over a cart is inherently unstable and nonlinear system. Our aim is to balance pendulum near to its vertically upright position while tracking the cart position for a given setpoint. CNF control law is proposed for asymptotical tracking of cart position and to make the process faster and smoother with fewer oscillations. The key to CNF control technique design is the combination of linear and nonlinear control where linear control gives quick rising time due to low damping ratio and nonlinear control provides high damping ratio to remove the overshoot resulting from linear part during tracking the reference. Simulations are performed to validate the theory and results are discussed.