The Research And Design Of ACU Test Equipment

With the continuous development of automotive electronics, all people need more and more automotive safety in their daily life. From the sixties of the last century, the Supplemental Restraint System has developed so many years, it formats active safety system and passive safety system, and both are indispensable. The airbag system is the core of passive safety system, and the airbag controller is the key of airbag system, so the airbag controller must be tested very rigorous before it be set in car to ensure it can correctly respond to changes in vehicle sensors in a short time. Different types of airbag controllers have different load, the same pin connected to the same type airbag controller may not have the same load, because of this, the test equipment of airbag controller has the function to simulate the real car environment, like judging the seatbelt access or not, warning lights work or not, and more important, this test equipment must switch the external loads freely. Besides the hardware, the test equipment must have the control area network or keyword interface, as the reason of automotive electronics, and besides, the software should meet the application layer communication protocol, when necessary, this test equipment should have the function of updating the software in airbag controller. This means this test equipment not only has the read access but also has the write access to the airbag controller, this requires the designer get the knowledge of the software in airbag controller.The project designs a test equipment, this equipment can test the quality of airbag controller. The hardware is composed of control board and relay matrix, on the control board, there are constant voltage and constant current circuit, serial peripheral interface, inter-integrated circuit interface and switch circuit of “pingpang” operation. The relay matrix is composed of relays and relay driver which provides enough current. The communication between lower computer and the upper computer is by serial port, the upper computer can display the test process and test result clearly, at the same time, the lower computer provides usb port for debugging the system and the in-application programming function, so the engineer can update the system in other place, not on the port.The airbag controller test equipment can test the several function of airbag controller, and play a great role in customer site, test out many bad products and avoid the risk of traffic accident, last but not least, it meets the requirement and goal of customer and is compatible with most of the products, reduces the test cost greatly.