Performance analysis of 2-link Robotic Manipulator with LPF and α-filter based UDE controller

Abstract

Robust trajectory tracking control of the 2-link robotic manipulator is analyzed by implementing two different filters in conjunction with UDE controller. The proposed controller is employed to estimate the uncertainties and disturbances and nullify their effects with an appropriate filter. The feedback linearization method is used for trajectory tracking and is extended with UDE to achieve robustness. A low pass filter (LPF) is augmented to the controller design when the external disturbance is constant or slow-varying. However, this technique is not sufficient to ensure robustness when the estimated disturbance is fast varying or sinusoidal. To address the problem, a $\alpha-$ filter is used in place of LPF. This novelty lies in the new filter design range sufficient enough to keep the error within an acceptable limit with an appropriate choice of cx. Simulations for 2-link robotic manipulator are carried out to demonstrate the efficacy of the two filter design.