Design Of A Universal BCM Automatic On-line Functional Test System

To meet the requirements of car users to improve the safety and comfort of the car, BCM application is used more and more widely, its security and reliability are particularly important, therefore, BCM products detection technology has become a research hotspot in recent years. Current commonly used BCM products inspection methods restrict test efficiency and cost to the manufacturer, the two main methods are artificial inspection and spectial inspection. Artificial detection is slow and subjective cause error rate is higher; spectial inspection requires for a different type of BCM when develope a new test system, and the test system is not general, whice increase the cost of development.Aim at the current problems which are slow speed, high error rate and poor generality to traditional BCM function test methods, based on the test requirements of four kinds of BCM of a BCM manufacturer,with the combination of the pseudo exhaustive testing method and the depth prior search, the automatic test vector generation algorithm is applied to system design, this paper designed and developed a set of universal BCM online automatic functional testing system. The algorithm reduces the special structure of multiple input multiple output of BCM to function block as the unit of structure, with the idea of starting from the shortest path, this paper proposes an automatic test vector generation optimization algorithm for BCM.The whole test system is built based on soft core technology.Take NIOS II processor as the control core and FPGA board for the I/O devices to build the hardware platform. Take.net as online automatic test software development environment, which has a friendly graphical human-machine interface, test function operation is simple and convenient.Based on the two aspects of hardware design and the mechanical structure of innovation, solve the technical problems of universal BCM test system:(1)according to the the advantages of FPGA multiple pins and programmable, with a soft core processor NIOS II panel instead of the commonly used data acquisition card, can simplify the hardware structure of the test system.(2) combined with PLC control advantages,adopt the combination of rotary conveyor belt, test needle bed and mechanical arm in a design, the different models of different time production BCM integration testing on the same production line, realize general agency, save the cost. In the development of the test, using multi-threading technology improve BCM test data acquisition and real-time display, shorten the testing time, guarantee the test precision, reduce the production cost.This system has been successfully put into production, from the point of the operation of the actual usage, the universal BCM online testing system has reached the expected design requirements.