Second Order Terminal Sliding Mode Control Of Linear Servo System

The development of modern NC machine is towards to a trend of high speed, high precision, composite, intelligence, green and environmental protection. Direct drive servo system is one of hot-spots on the field study of NC. Taking the permanent magnet linear synchronous motor as the control target and on the basis of running system that is accessible to uncertainties, such as parameter variation, load disturbance, end-effect and friction disturbance, also do some deep exploration on the strategy of speed central loop, design a novel second order terminal sliding mode controller so as to enhance the robustness and the rapidity of the controlled system. The research contents are as follows:Firstly, understanding the development situation and control method of linear motor at home and abroad, then permanent magnet linear synchronous motor servo system has been introduced in detail. The main disturbance factors have been discussed to decline the performance of the permanent magnet linear synchronous servo system.Secondly, the speed controller of PMLSM servo system is designed by using second order improved terminal sliding mode control technique to enhance the response speed of the system and let the system perfect robustness. Improved terminal sliding mode surface is designed to improve the system global convergence speed. The second-order sliding mode control methods weaken the improved terminal sliding mode control methods chattering. Finally, using the MATLAB/Simulink designs control system modeling and analyzes simulation basing on theory analysis.Finally, second order nonsingular terminal sliding mode control technique basing on adaptive control algorithms and the twisting control algorithms is designed to further increase the response speed and control accuracy of the system. The integration of adaptive control algorithms and twisting algorithms adaptively adjust the gain of twisting algorithm, in the meantime, there is no need to know the boundary of the controlled gain so as to enhence the control property of the designed system. Using the MATLAB/Simulink designs the control system modeling and analyzes the simulation results basing on theory analysis. With the second order terminal sliding mode control system of the Permanent magnet linear synchronous motor, the simulation results of the comparison prove the control precision of the designed control system is higher.