Research On The Technology Of Suppression In SCS For PMSLM

Recently, with the development of the direct drive technology, and thecharacteristic of linear motor, such as high efficiency, high precision and high velocity,linear motor has been employed more increasingly in the field of computer numericalcontrol machine tools. However, owing to linear motor is directly connected to theworkbench without any intermediate transmission mechanism, this way of working iseasily disturbed by external disturbance force and variation in parameter of plant. Thethesis is focused on the linear motor which is part of high speed and high precisionhorizontal machining center(HMC)’s direct-drive technology experimental platform,and what make the analysis and a part of the research is to provide the referencesolution for the programming of disturbance suppression in linear motor servo controlsystem.Firstly, the thesis briefly analyzes the basic structure, operation principle and thedistribution of the air-gap magnetic field of permanent magnet synchronous linearmotor (PMSLM). On the basis of those works, the disturbance that linear motor servocontrol system (SCS) may endure in the application of HMC and the causes of thedisturbance are also analyzed.Secondly, in order to suppress the perturbation of linear motor SCS, the frictionforce and the force ripple which are the mainly influences in the properties are analyzed,and their affection in the cases of low and high velocity is also researched. Ansoft V12and Matlab software are used to establish the mathematical model of the force ripplebased on position of linear motor.At last, according to the characteristics of the friction force and the force ripple, amethod based on the combination of the improved disturbance compensator andintelligent controller is proposed to suppress the disturbance on the linear motor SCS,this method which is verified by the simulation can effectively suppress disturbances.The improved disturbance compensator is set to improve the capability to suppress thestatic friction, transient disturbing force and the response speed to the disturbance. Thevelocity fluctuation is reduced by the composite controller combined the proportional integral (PI) controller with the repetitive controller. The fuzzy proportional integraldifferential (PID) controller with dead zone and integral separation is also designed toreduce the displacement overshoot, improve the response speed of this position loop, atthe same time maintain the relatively good track performance.