Design And Development Of Control System For Engine Torsional Vibration Simulation

Engine’s torsional vibration on shaft is a main factor influencing the performance and service life of engine and power train system. In order to test the performance(such as the rattle phenomenon of gear box) and service life of the power train system components,the conventional approach is to test it on the transmission test bench. But the general bench can not simulate the torsional vibration characteristics of engine,which can not provide the same conditions as the components work in the car, thus unable to evaluate the performance and service life of the components accurately. Therefore, the research of engine’s torsional vibration simulation control system based on power train system test bench is of great significance.This paper described the engine torsional vibration generating mechanism and studied its excitation source based on a four cylinder four stroke gasoline engine, and set up a mathematical simulation model of torsional vibration, then designed and developed the engine torsional vibration simulation control system, finally built up a test bed to verify the design.Firstly, the paper introduced engine’s torsional vibration simulation technology and measuring device, then put forward the significance and content of this topic.Secondly, this paper introduced the basic theory of torsional vibration and excitation of engine’s torsional vibration, and calculated the mathematical formula of engine’s torsional vibration excitation torque through the stress analysis of crank connecting rod mechanism, then achieved the relationship between the exciting moment and the cylinder gas pressure, and put forward using calculation method to configuration the theoretical indicator diagram of engine.Thirdly, according to the ideal gas equation of the engine’s working process and the corresponding boundary conditions, established a mathematical model of torsional vibration and simulated it with SIMULINK, finally got the engine indicating diagram and the engine’s torsional vibration simulation results.Fourthly, by analyzing the torsional vibration signal characteristics, put forward the specific requirements of engine’s torsional vibration simulation control system, and then proposed the overall hardware design of the control system. After that, built a control system hardware platform with selected hardware.Fifthly, in order to control the speed and torque of the motor fast and accurately by the converter, developed the PLC programs of the control system with programming software, and then developed the PC programs of the control system based on C #, completing the communication with the controller, data collection, storage and alarm functions between the computer and the controller.Finally, built a rear-wheel drive transmission test bench based on the design of the engine’s torsional vibration simulation control system, and verify the design.The test results indicate that, this design can accurate simulate the characteristics of torsional vibration in a certain range, which provided a good platform for further design and development of engine torsional vibration simulation control system.