Research Of Feeding Servo System Based On Fuzzy Self-tuning PID Controller

The performance of feeding servo system largely determines the processingquality of CNC machine tools. Conventional PID controller is commonly used withgood control effects and its regulation performance mainly depends on the PIDcontrol parameters. However, it is difficult to achieve online adjustment. As a kindof intelligent control, fuzzy control has strong self-adaptive ability, but the controlprecision is low and the stability is difficult to determine.This paper analyses the feeding servo system on the principle of vectortransformation control. Based on the dynamics and mathematical models ofmechanical transmission mechanism, the whole mathematical model of the feedingservo system is established. A fuzzy self-tuning PID controller is designed throughthe integrated advantages of fuzzy control theory and PID control technology. Whenthe system reaches the equilibrium position, the stability is difficult to determine dueto the addition of fuzzy control. What’s more, excessive control rules are easy tomake mistakes during the execution of the program. Therefore, the design addsanother PID controller on the basis of the fuzzy PID controller. The parameters ofPID controller and fuzzy PID controller can be set differently. By setting a certainthreshold to deviation of the system, the type of control system can be selected.When the deviation is large, the system uses fuzzy PID controller to adjust theoutput. When the deviation is small, the system uses PID controller to ensure thestability of the system.In order to verify the feasibility and effectiveness of this controller, this papertakes the feeding servo system as the research object. Under the step signal,interference signal and sinusoidal signal, the dynamic simulation of system signal iscarried out with Simulink toolbox in Matlab. By contrast with the simulation resultsof no PID control and conventional PID control, the fuzzy PID controller has bettercontrol performance. This method has high engineering practical significance andoptimistic prospects.