Comprehensive Occupant Classify System And Airbag Diagnosis Equipment

Airbag is one of the most important components which can enhance the safety of cars. Conventional airbag is designed for 50% Hybrid III dummies under normal seating positions. So if the passenger is small-sized people, children, or if the passenger is out of position (OOP), the huge energy generated in the process of airbag system ignition will probably cause injuries of occupants instead of protecting them. Therefore, it is necessary to develop an Occupant Classify System (OCS), so that the airbag controller can adopt specific ignition strategy according to different occupants'seating information, and thus reduce occupants'injuries caused by airbags. The development of electronic technology and the price reduction of electronic products render the development of OCS possible.Based on a review of traditional single-point ignition airbag controllers, the present study is intended to design and develop a comprehensive OCS, which can determine specific ignition strategy according to occupant's type and the occupant's seating situation, so as to avoid injuries caused by traditional airbag controllers. Thus occupants could be better protected, and the car safety will be enhanced. For the convenience of system debugging, production, and maintenance, the airbag diagnosis equipment is designed to test the system performance.The major work of this paper includes a market research, integral system programming, function demand analysis, theory design, hardware design, software design, system matching experiments and a primary analysis of control algorithm. The system adopts the integral control strategy of multi-point distributing measuring and intensive computing. In order to accommodate to the network inside the vehicles, the general CAN bus is used in the communication between different nodes for the sake of system conformity. Functional modules are distributed in different key positions in the car, including the OCS central control ECU, the ultrasonic distance measuring CAN node, passenger seating information CAN node, side collision information CAN node, and so on. The airbag diagnosis equipment also supervise andmaintain the system through CAN bus, including the airbag diagnosis equipment node and the display module.Under the current conditions, parts of module demarcated tests are finished, based on which the system's combined static debugging and primary system dynamic matching experiments are carried out. These experiments prove that each module of this system performs well and the output data are accurate and valid. Thus basically the system meets well with OCS design guidelines and can classify key information of occupants and send out the ignition signal accurately in the scheduled time.On the control algorithm, the traditional algorithm in the sole-point one directional airbag controllers is analyzed through specific experiments, mainly focusing on the influence of window width on the speed of ignition and counter-disturbance ability. Meanwhile, this study brings out three-directional integral acceleration algorithm especially for the OCS designed in this study. This algorithm combines the advantages of x, y and x, z dual directional integral acceleration algorithm. As a result, it can not only enhance recognition ability of various collision forms, but also promote the road counter-disturbance ability of the system.