Study And Implementation Of The Algorithm Of Sliding Mode Control For The Gantry Dual-drive Linear Motor Platform

With the continuous development of industrial technology, high-precisionmotion platform play a more and more important role in the field of precisionmanufacturing, testing etc. High-precision motion platform is higher for thepositioning accuracy, speed and acceleration performance requirements, whichpresents a greater challenge on the design of platform and the reality of motioncontrol system. The traditional “servo motor and ball screw” drive structure has beendifficulty in meeting the requirement, and the linear motor servo system can meet thehigh-speed, high acceleration applications better on account of structural advantage.The linear motor servo system is nonlinear, parameter perturbation, load disturbanceand other shortcomings; meanwhile, sliding mode variable structure controllerinsensitive to parameter variations and disturbances characteristic, So we designed anreaching law sliding mode variable structure controller. The simulation andexperimental results show that the controller can effectively improve the speed andthe stability of servo system, the servo system runs well.Firstly, the structure and working principle of permanent magnet linearsynchronous motor is analyzed, and then the under d-q coordinate systemmathematical model is established according to the coordinate transform method.Moreover, the principle and implementation methods of SVPWM vector controltechnology is analyzed. Finally, the linear motor vector control system simulationmodel in MATLAB/Simulink environment is established through vector controlstrategies.Secondly, the design principles and methods of combining sliding modecontroller is designed to apply to linear motor servo system approaching the rate ofvariable structure controller. The simulation research on servo system speed loop andposition loop show that the sliding mode controller have the characteristic of fastresponse, strong robustness and anti-interference ability etc compared withtraditional PID controller. Finally, experiments are carried out in the dual-drive linear motor gantrymotion system platform to verify the performance of sliding mode controller. At first,the structure and principle of the whole movement of platform is introduced, andthen the sliding mode controller model is built in the MechaWare motion controltoolbox. Experiments are conducted by loading model in motion control card.Through a series of experiments show that under the action of sliding mode variablestructure controller the linear servo motor control system has fast dynamic response,without overshoot and strong robustness property, good dynamic and staticperformance as well.