Design And Implemention Of A Car Airbag Control Unit

As the main module of the vehicle passive safety system, it is efficient to protect thedriver and passenger when the airbag module is matched together with the seat belt, and moreand more automobile manufacturers and users pay the great attention to that. After thedevelopment and promotion in these years, the airbag modules are already universal applicationin the Sedan and SUV etc, successfully save many lives during the traffic accidents, the airbagmodule is accepted and agreed by more and more people. ACU (Airbag Control Unit) is thecore module of the airbag safety system, the works of the airbag safety system are controlled byACU, and the performance and function of the system is determined by ACU. ACU has highReal-time, high reliability and high security. In China, People study and develop the ACUModule is later than foreign, compared to the foreign ACU company, the study anddevelopment of our self-owned brand ACU is fallen behind, and the function of ACU is single.Along with the development of the vehicle industry and the expanded of the marketrequirement, people have the higher requirement of the airbag modules and the airbag controlunit. It is the opportunity and the challenge to the self-owned brand ACU. It is very important ofthe internal company to make the ACU with good function, good expanded part and all-sidedinterface.The paper explains the composition of the airbag system and development status in Chinaand foreign firstly, make the analysis and discussion of the core technology for the airbagcontrol unit. And point of view the requirement of airbag safety system in China, make thesystem structure design, function design and software structure design of the airbag control unitaccording to the current technology status, and confirm the system software process. The paperalso show how to make the design of the hardware implementation from the hardwarerequirement of the airbag control unit, and complete finally design of the hardware system bythe hardware design of sub-modules: the type selection of the Micro Control Unit, sensor circuiton the board, fire driver circuit, Can interface, ASIC circuit of the airbag module andperipherally sensors. The paper emphasis to introduce the software design process andimplementation method of the airbag control unit, specially introduce the function and softwaredesign process of the ignition control, failure diagnosis and message service three modules, and application advantage and detail software implementation of the airbag control unit by thedual-core processor, and complete the finally design of the system software. At the last, thepaper introduces the testing of the parts function, testing of the software arithmetic and ACUimplementation status. The paper also for airbag control unit of the function of performance test,software algorithm of testing and product realization use is introduced in this paper. Accordingto all parts of the design method, debug through the airbag control unit of the function of thehardware diagram design samples, PCB design, function and the manufacture of the sample andthe writing of the software and commissioning, complete function of the samples making. Andaccording to the sample testing and debugging results, the hardware diagram, PCB andsoftware design were modified, and eventually completed the airbag control unit and peripheralsensor design work. In addition, it also designed and produced the corresponding PC diagnosiswith USBCAN conversion software and diagnosis of the assistant tools, etc.The paper expound the design and the implemention process of the ACU, the systemreliability of the ACU is increased by the dual-core of the MCU, the redundancy technologyof the paired ACU, the secure logic technology and the peripherally sensors etc, ACU withthe functions can meet the system requirement.