Design And Implementation Of Automatic Testing Equipment For Body Control Module Of Automobiles

With the development of modern IT, electronic control device are increasingly used in modern automobiles. Body control module is one of the most important electronic control devices of automobile, including central lock control, electric glass control, guard against theft and alarm control, light control, airbag control and rain brush control etc. Nowadays, Body Control Module (BCM) can be designed independently in domestic manufacturers and also be manufactured in batches. Nevertheless, the situation that the test of products is in the level of manual test seriously restricts the total production efficiency. It is necessary to develop an automatic test system of body control module for automobiles.For the purpose of functional validation this paper establishes a test model for the BCM of automobiles. In the model, a multiple input and multiple output (MIMO) structured system is decomposed into several multiple input and single output (MISO) structured modules. A shortest path-searching algorithm used to generate test sequence is also proposed according to the test model.The whole test system is constructed using Virtual Instrument techniques. On the aspect of hardware, using industrial PC as its control device and PC-DAQ card as its I/O device makes it easy to reconfigurate the test platform. On the aspect of software, LabWindows/CVI is used as a development tool for the test application software, which provides friendly GUI and convenient programming environment.Some key problems in developing the hardware system of the BCM test equipment are solved in this paper, including the analog of motor load under off-vehicle circumstance and strong current detection. Parallel connected Darlington transistor and power resistor are used as basic structure for analog load. The Hall current sensor is used to detect strong current. In addition, considering the system reconfiguration, the interface circuit from BCM to PC-DAQ card, as well as the communication circuit for data exchange from BCM to IPC is designed.During the development of test software, the thesis solves the control problem of DAQ card not produced by NI Company, as well as the problem of handing real time multitasks. Dynamic Link Library technique is used to call the functions provided for the VC environment. Multithread technique is used to realize real time data sampling and displaying, as well as the automatic test process control.Finally, the developed BCM automatic test system is introduced. The real world applications of the BCM test results demonstrate that the developed system meets design specifications and satisfies customs demands.