Design Of Test Bench Oriented To Hub Motor Faults And Its Research On Diagnosis Method

Hub motor has a variety of functions including driving,braking,bearing in one,it is recognized as the best choice for the future automotive power system with many advantages of flexible control,compact structure and high transmission efficiency and so on.Facing the variable working conditions and complex road conditions,the operation safety and service life of the hub motor have become the key problem that restricts its development.In order to speed up the development of energy saving and promote the transformation and upgrading of the automobile industry,it is very necessary to carry out the research on the theory and method of the state monitoring and fault diagnosis of the hub motor.This paper takes the hub motor as the research object,taking its fault diagnosis technology as the research focus,developing the diagnostic function base of the test bench,extracting the characteristics of the motor state signal,establishing the motor fault diagnosis system,identifying the type and degree of the fault.Firstly,the structure,principle and functional requirements of the hub motor are analyzed.A new platform frame construction scheme is proposed for the limitation of the traditional test bench structure,and a variety of hub motor test techniques are expanded to complete the structural modeling and part selection.Secondly,analyzing the common mechanical fault and diagnosis requirements of the hub motor,formulating the principle of diagnosis process and parameter selection,aiming extracted precision of the motor state signal,optimizes the signal measuring point by ANSYS Workbench modal analysis,optimizes the structure of the platform to reduce the noise,analyzes the source of noise and the corresponding de-noise methods.Thirdly,the hub motor fault diagnosis test bench is set up,the multivariable test scheme is designed,besides the method of the motor bearing fault simulation is put forward to obtain the state signal of the motor under different working conditions and excitation.Analyzing the signal characteristics based on the MATLAB,the effect of the variable influence is analyzed,and the theoretical modal analysis results are compared to verify the reasonableness of the structure design as well as the test scheme.Finally,according to the signal of the hub motor fault diagnosis test,the characteristic parameters of multiple state signals are extracted.Based on the possibility theory,the motor state identification system is established,and the distribution of characteristic parameters is studied.The DI value is used as the evaluation index of the position of the vibration signal.The results show that the diagnostic accuracy of the hub motor state identification system is as high as 87.5%.This paper focuses on the research on the fault diagnosis function of the hub motor,develops the bench test technology,studies the fault diagnosis method,starts with the extraction precision of the motor vibration signal,and develops the structure design and the optimization of the test point,and establishes the motor fault diagnosis model based on the possibility theory,and combines the modal theory to analyze the test signal.The results show that the structure of the platform designed in this paper is reasonable and the function of fault diagnosis is effective.It can provide reliable platform and technical support for the performance improvement of hub motor technology and the research of operation safety evaluation.