Design And Implementation Of Voice Coil Motor Control System Based On Full Fractional Order Sliding Mode

In recent years,the scale of voice coil motor market has been growing steadily and has a broad prospect,which benefits from the rapid development of its application fields,especially in the fields of optics,semiconductor,vibration,precision machining and so on.The production and processing actions in these fields are mainly positioning,tracking,pushing and feeding,and are often reciprocating motion,which requires high speed,accuracy and stability.Therefore,voice coil motor with light weight,fast response,high precision,simple and reliable principle has become the best choice.Based on this background,this paper studies the control algorithm of voice coil motor and the design and implementation of the control system.In this paper,the working principle of voice coil motor is analyzed,the mathematical model of the motor is obtained,and the three closed-loop control system model is established.Because the sliding mode control has the advantages of strong robustness,high anti-interference and rapid response,and the voice coil motor structure is simple and stable,which is suitable for sliding mode control,so this paper designs the sliding mode controller for the control system.The disadvantage of sliding mode control is chattering.And through the simulation experiment,it is found that the principle of traditional chattering suppression method will sacrifice the rapidity of the system.In order to improve the performance,this paper introduces the fractional calculus theory,and completes the solution and Simulation of fractional order operator in complex frequency domain on matlab/simulink platform.The input and output characteristics and logarithmic frequency characteristics of fractional steps are analyzed.On this basis,a controller of full fractional sliding mode(fractional sliding mode surface + fractional order approach law)is designed and simulated.At present,the controller combined with fractional order is only PID and sliding mode,so the fractional PID controller is designed as the comparison of fractional order method.In this paper,TMS320F28335 is used as the main control chip,and the hardware circuit of the system is designed in Altium designer platform,mainly including the minimum system,auxiliary power supply,H-bridge drive,current sampling,position feedback and other circuits.The hardware platform of the motor control system is built.The software program of the system is developed on the platform of Code Composer Studio,including initialization configuration,interrupt service,discrete numerical solution of fractional order operator,etc.In this paper,the influence of fractional order parameters on the sliding mode control is simulated and debugged,and four groups of control experiments are designed.It is proved that the full fractional order sliding mode control has the fastest response,the strongest anti-interference and the smallest chattering.The program is run and debugged on the hardware platform,and the results show that the system can track the control instructions accurately and quickly.In this paper,the full fractional order sliding mode control strategy based on voice coil motor is designed and implemented for the first time,the experience of parameter tuning is summarized(and the setting method of sliding mode parameter C is improved from the reality).These works not only fill the research gap,but also have certain engineering value and guiding significance.