Research On The Control System Of Dedicated Switch Life Test Bench By Automobile

In the car’s research and development and using process,automobile switch occupies a very important position,and automobile switch life test bench is mainly used to test whether the switch’s service life reaches the standard in switch production enterprises,so it can provide more and more valuable data which can be referred to by the design department.This thesis is a part of the project of cars’ switch life experiment platform in Changchun Automotive Research Institute,and it mainly studies the working principle and control system design scheme of the experimental platform of automobiles’ dedicated button-type low-voltage switch life,and then it makes a research on the control algorithm.The system control scheme conducts a special design by mainly aiming at step motor closed-loop drive parts.First of all,this thesis studies the requirements related to the experiment of automobile switch,and then analyzes the mechanical structure of the experiment table.The mechanical structure of experiment table is designed into a two-piece mode,and the upper part is a press mechanism,which is driven by the cam,while the lower part is a switch positioning device,which is implemented by a way of rolling screw driving.By comparing the characteristics of different control motors,it selects three-phase hybrid stepping motor as the driver of test bench.Then starting from the structure principle of the selected motor,it sets up a mathematical model of three-phase hybrid stepping motor,and designs the overall electric control system.Later,it studies the processor,drive mode and modulation system,and puts forward vector control SVPWM subdivision driving scheme based on TMS320F2812,and then the hardware system is designed and implemented.In order to improve the performance of the control system of test bench,and after combining the classical PID control theory with modern fuzzy control theory,it constructs a fuzzy PID controller structure which is suitable for the requirements for stepping motor control,designs the corresponding control rules,implements the stepping motor control,and improves out-of-step and vibration phenomenon existing in the stepping motor control system.In order to validate the control effect,it adopts MATLAB/Simulink to construct a three-phase hybrid stepping motor model and gain-type fuzzy PID control algorithm model,which control the revolving speed and torque of the stepping motor with the speed and current double closed-loop.After making a large number of simulation experiments,the results show that the three-phase hybrid stepping motor control system designed in this thesis has a good torque and rotational speed output,and it can improve the electrical control performance and effect of the test bench.