Anti-windup Controller Design using Gravity Compensation with Parameter Estimation Error for Euler–Lagrange Systems with Actuator Saturation

A static anti-integrator-windup controller design that employs gravity compensation and takes parameter error into consideration is proposed for Euler–Lagrange systems. Gravity compensation is performed by treating the time derivative of the gravity term for asymptotic stability based on passivity when actuator saturation occurs. A new design variable is introduced to increase the degrees of freedom of controller design. The optimality of the proposed PI controller is examined using an estimation function for actuator saturation. The proposed controller and its optimality are verified by numerical simulations and experiments using a two-link robot arm.