Study On Principle Of Semi-Automatic Gearshift System Of Car And Development Of Control System

With the development of automobile industry, car is commonly used in our daily lives. As it brings us the convenience, it also causes air pollution, noise, heavy traffic jam and accidents. One of the major causations is tiredness driving, so how to reduce the negative effects and make gearshift easier and comfortable to control is a critical issue for the ministry of communications to deal with.This subject makes an improvement which is based on the original gearbox. By using the Electronic Pneumatic shift system, it can achieve the properties of fast response, easy control, reduction in operation without losing the original gearbox's merit of high efficiency, low coast, and simple structure. This system can reduce the working intensity of the drivers. Further more, less accident would happen. So it has important theory and application value to study on this subject.The whole system is made up of the control system and the execute system. They communicate between each other by CAN Bus. When the driver gives the order to shift gears, the control system collects and analyzes the signals of the handspiker's position, then the order of gearshift is sent through the CAN Bus by the MCU P87C591 which has a can interface. In order to reduce the drivers' working intensity, the execute system will finish the gearshift operation automatically by adjusting the rotate speed of the motor to a suitable speed with the help of the synchronizer. The execute system will give back the final state of the gearshift to the control system to finish the gearshift operation. The driver should separate the clutch to get a smooth startup just at the beginning.This system makes an improvement in gearshift operation and accelerograph control. It can reduce the drivers' working intensity and is easier for the mender to repair it with the application of CAN Bus. CAN Bus communication can meet the gearshift control system's strict restriction in realtime and reliability for its excellent error correct mechanism, reliable and higher baud rate in data transmission. The system is reliable, efficient and fast in response to gearshift control. It is also cheaper in manufacturing cost.