Research On The Key Technology Of Mini-van Drive-axle Testing System

With the possessing capacity of Mini-van in China growing rapidly, the testing for Mini-van reliability and performance is becoming particularly important. For traditional electric drive axle enclosed comprehensive performance test methods, the effecting of road roughness is always ignored and in this Dissertation an optimized testing plan based on electro-hydraulic road roughness simulation technology was presented.The dissertation is supported by the project’Wan Xiang micro-electric drive axle enclosed test bench’, led by ZheJiang University Vehicle Test Researching Team. In this paper we use the electro-hydraulic servo actuators to simulate the impel engendered by road roughness and vehicle weight, in order to reappear the driving conditions, by means of a combination method of physical test,theoretical analysis and matlab simulation.Firstly, the development and current status of the vehicle test technology and electro-hydraulic excitation technology were introduced. In the second chapter we establish a simplified road-tires-drive axle vibration physical model and build a Simulink model based on dynamic equation. And then, we do some theoretical analysis on the describing methods and mathematical model of road roughness characteristics and reconstructed the discrete pavement roughness sequence signal according to the power spectral density function. Finally, the remote parameter control technotlogy was introduced briefly.The third chapter was focused on the core department of the testing system-electro hydraulic road roughness simulation actuator. The three-stage electro-hydraulic servo valve is the control component of the electro-hydraulic actuator. Firstly we introduced the working principle and overall design scheme of the road simulating actuator. We have done much work on analyzing and simulate the dynamic properties of the electro-hydraulic system and optimized the control strategy, broadening the frequency response to over 50Hz.The fourth chapter describes the overall design of this testing bench. In this chapter mechanical solutions, electrical control solutions and software design are introduced. Besides it describes some problems concerning the selection of main equipments, including the motors, torque meter, actuators and other major equipment. Finally, we summarize the advantages and disadvantages of the program and advance some reference ideas for the further work later.