Multiple Objective Optimization Research Of Double-secondary Permanent Magnet Linear Synchronous Motor Based On RSM-FA Method

With the rapid development of modern equipment manufacturing,the demand for high precision machine tools is increasing.The traditional machine tool feeding system transforms the mechanical energy produced by the rotary motion into linear motion mechanical energy of the intermediate transfer device.Machine tool feeding system is usually combined with a rotary motor and ball screw,or the combination of a rotary motor and gear rack.There are a series of unavoidable problems such as deformation,wear and noise in the transmission process.Permanent magnet linear synchronous motor(PMLSM)can eliminate the intermediate link,avoids a series of problems and directly produces linear motion mechanical energy.It has the advantages of fast dynamic response,high positioning accuracy and simple structure.It can effectively improve the machining precision of machine tool and meet the requirement of high precision machine tool feeding system.Due to the characteristics of its own structure,PMLSM hss end effects,armature reaction,non-sinusoidal distribution of air gap magnetic field and other issues.The motor has vibration and noise during operation.The influence of different structural parameters on the output performance of PMSLM is different.A single change of a certain structural parameter to optimize the motor will affcct many output performances of the motor.In this paper,the corresponding researches on the small double-secondary PMLSM used in laser cutting machine.After the motor body design,combined response surface method(RSM)and firefly algorithm(FA)to solve the PMLSM multi-objective optimization problem.The concrete research content is as follows:1.According to the structural characteristics of the double-secondary linear motor,the equivalent magnetic circuit model is established and the output performance of the PMLSM is analyzed.The key structural parameters affecting the performance of the motor are analyzed qualitatively,such as the parameters of a permanent magnet.polar distance and coil parameters.The analysis provides a theoretical basis for the subsequent multi-objective optimization design.At the same time,the method of controlling the thrust ripple of the motor is introduced,and the design of the motor structure is optimized by unequal pole-arc coefficient combination.2.Introduces the Finite Element Analysis(FEA)principle and the parametric scanning technology.The FEA model of PMLSM is established.Analyzes the advantages and disadvantages of the FEA modeling which applied to multi-objective optimization design.And finally parametric scanning technology was used to solve the motor performance with unequal polar arc coefficient structure.The results show that the output of the motor can be effectively improved.3.Using the RSM-FA method to solve multi-objective optimization design of double-secondary PMLSM.Firstly,the range of parameters to be optimimized is determined and the sample points are determined by using the central composite test design method.Secondly,the motor performance of each sample point is calculated by FEA,and the model of high precision motor thrust and thrust ripple model is established by RSM.According to the optimization goal,the multi-objective optimization model of PMLSM was established.The model is optimized by FA to obtain a set of optimal parameter combinations.4.A set of double-secondary linear motor structure parameters obtained by RSM-FA method machining parts and assembly motor.The output performance of PMSLM prototype was tested by the test platform.FEA simulation results with the prototype test result shows that the proposed range pole arc coefficient of combined mechanism can restrain the thrust fluctuation of the motor,and proposed the RSM-FA method can effectively solve the problem of multi-objective optimization of PMILSM,is of great significance to the optimization design of the motor.