Research On Shift Control Of High-power Automatic Transmission

Since the beginning of the 21st century,China’s economic level has developed rapidly,and automobiles have gradually changed from luxury goods to something that everyone can afford.And automatic cars have gradually become the most popular product because of a series of advantages such as convenient driving,safety and reliability.Automatic transmission(AT)is widely used in various motor vehicles such as cars,buses,and military off-road vehicles because of its advantages of simple operation and good power performance.The auto shift control technology is the core technology of automatic transmission research and development.The quality of shift will directly affect the passenger’s feeling,the power performance of the car and the life of the automatic transmission.This article is based on the Win Star 3600 automatic transmission jointly developed by Guizhou Win Star Hydraulic Transmission Machinery and The Institute of Electro-hydraulic Servo Simulation and Test System of Harbin Institute of Technology.To solve the actual problems of this type of automatic transmission,This article analyzes and controls the shift process of this automatic transmission.The main work of this article is as follows:Firstly is to establish the mathematical model of automatic transmission and experimental car.This step include establishing the automobile engine,hydraulic torque converter,planetary gear mechanism,wet clutch and other key components of the automobile transmission system and the mathematical model of the entire automobile.And then use Matlab/Simulink to simulate established mathematical model,and compare with the parameter curve obtained by actual car driving,to verify the accuracy of the mathematical model established.Secondly,divide the shifting process of the car into stages,take the most representative shift process,upshift from three-gear to four-gear as an example,Analyze the shift process based on the mathematical model established in the previous article,and combined with the engineers’ debugging experience and the actual vehicle test curve to analyze the abnormal state of the vehicle during the shifting process,and then point out the influencing factors that cause various shifting abnormalities.Thirdly,Determine the best shift speed point according to the car parameters.The traditional evaluation standard of automobile shift quality is introduced,and an improved evaluation standard of automobile shift quality is proposed based on the actual driving situation of the automobile.Propose and design a shift parameter automatic adjustment system based on HSIC and fuzzy control algorithm.The system can judge and automatically correct the abnormalities in the vehicle shifting process based on the improved vehicle shift quality evaluation standard.Shift parameters to improve shift quality.And use the hardware-in-the-loop simulation system to verify the effectiveness of the system.Finallly,use the experimental vehicle to verify the automatic adjustment system of shifting parameters.When the shift control parameters are not ideal,which results in poor shift quality,the abnormality of the shift process is detected and the control parameters are adjusted.Experiments show that the automatic adjustment system for shifting parameters can effectively improve shifting quality.