Robust Precision Motion Control of Linear Motors with Dynamic Uncertain Compensation

The influence of external force disturbances on Linear motors (LMs) is more obvious compared with their rotary counterparts because of the reduction of gears. The dynamic model of LM is representatively multivariable nonlinear. The control performance of LM is significantly affected by a myriad of nonlinear factors, such as electromagnetic force ripple, viscous friction and magnetic cogging force. In order to control a LM more efficiently and mitigate the impact of parameters uncertain, a novel robust compensation scheme is designed to address the precision motion control problem. In the proposed scheme, only uncertain boundary are utilized to make the LM system practical stability. The compensation scheme for uncertainty does not need its statistical information, and the system performance can be described in a deterministic form. Furthermore, theoretical analysis is provided to demonstrate that the controller can guarantee the uniform boundedness and uniform ultimate boundedness. Simulations and experiments validate the excellent effect of the designed approach, which can reach higher control accuracy and has good robustness to the variety of parameter.