Studies On The Interface And Anti-Jamming Of The Vehicle Stability Control System

Four wheel steering technology is an important method to improve vehicle steering performance. Vehicle stability control system is a leading technology in active safety. As an important part of VSC system, direct yaw-moment control improves the performance of handling stability much better, then increases the active safety performance. Anti-lock break system controls the lateral of the vehicle. The connection of these technologies will improve the performance of handling and stability, and has important effect for avoiding traffic. This dissertation introduced the design of the interface of the vehicle stability control system which would connect the 4WS, DYC and ABS. The main contents contain:1. The hardware design consists of two parts one is how to realize the switch between the ABS and DYC. DYC controls the transverse of vehicle stability and ABS does it work when meets a emergent condition in order to control the lateral of the vehicle stability. But ABS and DYC are integrated together. Considered the cost and the feasibility of the design, the author only used two pieces of 74LS373 to achieve the objective; Connection of 4WS and DYC is an important technology of the advanced vehicle stability control system. In traditional hardware in the loop experiment of four wheel steering system the clutch's on and off is controlled by the power's on and off. It is too inefficient. So a kind of circuit which would could detect the angle of the rear wheel was implemented. The clutch's on and off would control the start and stop of the motor, thus the rear wheel's steering had been controlled.2. The communication between the ECUs and all kinds of sensors. This project did some researches on the CAN bus. CAN is an acronym derive from Control Area Network which is one of the most popular bus within the vehicle. Using this approach allows the ECUs and sensors work reliably. Considering the properties of signals which were collected by the sensors and the cost of each CAN node, different signals used different microcontroller. According to the digital signals used 51 controller as the brain, SJA1000 and PCA82C250 which were producted by Philips, using these two chips and the embedded software so that the signals collected by the sensors could be transferred into CAN messages thus the communication between the ECUs and sensors based on the CAN bus was implemented. But according to the analog signals must be regulated first then used DSP (Digital Signal Processor) which integrated with AD and CAN controller to change the messages into CAN massages. Because all the messages must be received by the ECUs as soon as possible it was said real-time. So the ECU node used DSP2812 which was an advanced digital signal processor with the high and accurate operation ability. Using these intelligent CAN nodes the communication of the whole vehicle stability control system was achieved.3. CAN is defined physical layer and data link layer. The application layer is defined by the users themselves. It means the protocol will be written by oneself. This dissertation introduced the protocol of the vehicle stability control system which consisted of ABS/DYC and 4WS.4. At last, the dissertation introduced the methods of anti-jamming, Especially focused on the PCB layer and the jams in the vehicle tests.Through designing, doing, debugging the hardware and hardware in loop experiment, It can be seen that the platform of the vehicle stability control system which consists of ABS, DYC and 4WS has been built. What's more, the advantages of communicate with ECUs and sensors based on the CAN bus are not only reduced the quantities of wires but also made the whole system work reliably, Preparing for the future's research.