Controlling Strategy Research On Micro Permanent Magnet Linear Motor Based On Thrust Force Ripple Restriction

MEMS(Micro Electro-Mechanical Systems)has a wide range of applications such as aerospace,medicine,information,precision manufacturing,national defense,and etc.As an important branch of the micro-drive,the electromagnetic micro-drive has the advantages of long stroke,fast response speed,large driving force,etc.,and has long working life,strong anti-interference ability,easy to assemble,and easy to be practical,attracting the research attention of the majority of scholars.As an important form of electromagnetic micro-actuator,the micro linear motor can remove the influence of the accuracy error of the transmission mechanism on the positioning accuracy of the motion system,and can achieve greater acceleration,which is suitable for applications that require high precision and quick response occasions.The research object of this paper is a new type of micro-permanent magnet linear motor(micro PMLM)using micro-machining manufacturing technology,which is mainly used in the field of high-precision industrial manufacturing.This article aims to study the control system of the micro linear motor to suppress the thrust pulsation of the motor and improve the dynamic response performance of the motor.First,this article introduces the electromagnetic micro-actuator in the micro linear motor and the current research status of the linear motor,clarifies the background of the research in this article,and emphasizes the significance of the research in this article.Next,this article first conducts research on the mathematical model of the micro permanent magnet linear motor,by deriving from the magnetic field distribution of a single permanent magnet in space,and using the principle of superposition to obtain that the permanent magnet of the micro permanent magnet linear motor moves in the air.Based on the magnetic field distribution in the gap,the thrust equation of the micro-permanent magnet linear motor is obtained.Combined with the voltage equation and the motion equation,a complete mathematical model of the micro-permanent magnet linear motor is obtained.Next,this article analyzes the thrust pulsation problem of the micro permanent magnet linear motor.By clarifying that the thrust pulsation source is the harmonic components in the air gap magnetic field distribution,a control method for injecting odd harmonic components into the current excitation is proposed.This paper starts with the third harmonic current,derives and promotes the elimination mechanism of thrust pulsation,clarifies the mechanism of odd harmonic current injection to eliminate thrust pulsation,and proposes the use of proportional integral control and quasi-proportional resonance under multi-rotating shafts.Harmonic current injection is carried out by methods such as proportional-integral control in multiple rotating coordinates,quasi proportional-resonance control and complex vector proportional integral control.By building a simulation platform,this paper verifies the effectiveness of current harmonic injection to eliminate horizontal thrust pulsation and the position closed-loop effect based on current harmonic injection.Subsequently,in order to further improve the response speed of the miniature permanent magnet linear motor,this paper proposes to use the current predictive control method to optimize the delay links in the system.This article analyzes the main delay links in the control system,clarifies the mechanism of the voltage command’s effective delay,and derives the mathematical model of the current predictive controller for this problem.In addition,this paper proposes an improved method of current prediction controller,for the traditional current prediction method has high dependence on system parameters and weak anti-parameter disturbance ability,and carries out corresponding theoretical derivation.Finally,simulations are used to verify that the improved current predictive control improves the response speed of the current loop and its robustness under the disturbance of resistance,inductance and rotor flux parameters.Finally,this paper designs and produces the prototype of the micro permanent magnet linear motor controller,and uses the code generator of the MATLAB/Simulink platform to complete the matching software control system,builds the micro permanent magnet linear motor experimental platform.Injects the controller current harmonics It is verified with the function of reducing thrust pulsation,and the motor operation test is carried out to verify the operation performance of the control system.