The Development Of Automobile Braking Performance Test System Based On Can Bus

Nowadays, automobiles play a very important role in people's daily life. With the development of society, people has higher and higher requirement on automobile performance, especially the security of automobile. Automobile braking performance directly influences the security of automobile, therefore automobile braking performance is a crucial test item.After doing some research on the current development of the automobile braking performance test system at home and abroad, this thesis firstly analyzes the advantages and disadvantages of domestic automobile braking performance test system. According to the GB12676-1999 and the condition of the automobile braking performance test, an automobile braking performance test system based on CAN bus is developed. This system is made primarily of automobile braking performance test. In addition, the system can test dynamic performance of automobile.According to the functional requirement of automobile braking performance test system and the complex situations of field experiment, this system includes portable computer and data acquisition device. Portable computer is used as the upper computer of the system. And the software of the portable computer interface is developed by Borland C++ Builder. Data acquisition device consists of data acquisition master module, data acquisition extension modules and monitor modules. The microprocessor of every module adopts Silicon Laboratories C8051F series single chip microcontroller. Portable computer communicates with data acquisition device via USB to ensure the real-time performance of data transmission. On account of large amount, abundant information and high data rate, a perfect communication protocol is essential. Data acquisition master module communicates with data acquisition extension modules via CAN bus. Data acquisition master module communicates with monitor modules via short distance wireless communication. Then designed the various communication interface circuits; such as CAN bus interface circuit and USB interface circuit. And different kinds of transducers have different signal conditioning circuits. According to the functional requirement and the working process of each module, the software was designed. All the program flowcharts are presented.After finishing debug the hardware and software, the performance of the system was tested. The test results show that the system has complete functions, and the performance meet the requirements.