The Improvement And Study On Electric Motor Traction System For Vehicle Crash Test

With continued growth in vehicle ownership and the speed of the car in China, Vehicle crash accidents involving personal injury collisions have been quietly leapt to the top of social security issues. Therefore, in this type of accident and put forward higher requirements to the passive safety of the vehicle. Vehicle crash test is the most basic and effective method to evaluations and researches comprehensively automotive passive safety, The basis carrying out the experimental study must have a set of traction system to be provided with Complete function, Safe, reliable and easy to control. So studying and improving the electric motor traction system of vehicle crash has the important significance.In this thesis, by means of China Automotive Technology and Research Center establishes the Vehicle crash standard laboratory for National Automobile Quality Supervision and Inspection Center as cooperation projects. Regard the motor traction system on vehicle collision of CATRC as the research object, the system includes mechanical traction device and electrical control devices. By electrical control device supply mechanical traction devices required electrical energy the real-time, and by mechanical traction device converts into mechanical traction, so that drags and accelerates test vehicle to completes the relevant collision test. Through access to the relevant documentation of the domestic and international product design methods, and communicating with the engineers and actual site visits, finding part of the mechanical traction device of the system exist structural design flaws and shortcomings, After in-depth analysis, Carried out the improvement and study as the following aspects of design:(1)Through studied Overall structure of the mechanical traction device and working principle in detail, and established a physical assembly models of it, and displays the form of the structure of the device and the positional relationship between the various components and the relationship between the transmission visually, it pointed out the existence of mechanical traction device design flaws and shortcomings, and proposed the method and program to improve the structure. Focusing on the traction power output mechanism, hydraulic tensioning mechanism, mechanical tensioning mechanism and wire rope guide mechanism and improved the structure design.(2)Though kinematics and dynamics theory to estimate and select DC motor power; and makes a certain validation to the selected wire rope which meets the requirements by the actual situation; In the case to meet the test requirements, Redesigned enough moment of inertia of the drums having small mass; The original key transmission hydraulic cylinder and the screw and nut were designed to calculate and check the selection and proved the strength and stability of components to meet the design requirements of vehicle crash test.(3)using the wide flange of H steel for the mounting base overall design, layout the entire mechanical traction devices installed in the same basis to improve its accuracy and convenience on the installation and use; in the light of the improved hydraulic tensioning frame, the selection and design of open linear slide structure, increased flexibility when tension wheel works; Respectively integrated design the similar structure of the mechanical tensioning mechanism and wire rope guide mechanism to simplify and improve the practicality; according to the improvements in the mechanical wire rope traction device in actual use needs, design the auxiliary of wire rope guide mechanism to realize the supporting and guiding to rope wire, improve the role of the drum wrap angle. Through established the physical model of mechanical traction devices improved and carry out interference checking to prove there is no interference between the various mechanism, designed in line with expectations.The thesis also analyzed the composition of motor traction system control part, working principle and each device layout and installation requirements in detail, describes the system uses the CAN bus and RS485communication technology formed the host computer system, each control node and network management control function, By the process setting the parameters of the traction control system, described the loading Environment of the computer control system environment,Focusing on the system using the type of laser speed measuring device to measure with the two-point measurement pattern, from the theoretical and practical tests and analyzed the measurement accuracy and speed error of it. The results show:the higher the speed is and the greater the measurement error is, the longer measuring the length is and the smaller measurement error is.