Adaptive control approach for improving control systems with unknown backlash

Backlash which severely limits the overall system performance is common in mechanical and hydraulic systems. In this paper, the development of an adaptive control scheme for systems with unknown backlash is presented. An adaptive backlash inverse based controller is applied to the plants that have an unknown backlash at its input. The harmful effects of backlash and the compensation of backlash by adding a discrete adaptive backlash inverse structure and the gradient type adaptive algorithm which provides the estimated backlash parameter are presented. The supposed adaptive backlash control algorithms are applied to the aircraft with unknown backlash in the actuator of control surfaces for demonstration. Simulation results show that the proposed compensation scheme is the way of improving the tracking performance of the systems with backlash.