Enhancement of Energy Saving and Precision Motion for Industrial Machines by Adaptive Sliding Mode Control and Friction Compensation

Improvement of consumed energy reduction and motion accuracy in industrial machines is a significant requirement in manufacturing applications. The motion accuracy of industrial feed drives typically can be improved by increasing control gains of their feedback control algorithms. Although this strategy may improve tracking performance of the control system, it increases energy consumption. Another concern in most industrial machines is mechanical friction, which adversely affects not only the tracking performance but also energy consumption. In this paper, a new control scenario, which consists of adaptive sliding mode control (ASMC) and nonlinear friction compensation is proposed to enhance the motion accuracy and energy saving in an industrial feed drive system. The presented friction model can be flexibly extended to multiple nonlinear terms to well describe an actual frictional property, and therefore control efforts dissipated due to unknown frictional effects can be reduced. Furthermore, the applied adaptation scheme is able to simultaneously provide appropriate control signals based on tracking errors. Hence, the proposed control approach is expected to achieve higher motion accuracy and energy saving. Experimental results show the effectiveness of the proposed scheme on reducing energy consumption and also achieving a precise tracking to desired motion.