Research And Development On Test Bench For Braking Control Units Of Metro Vehicles

The braking control units have to be tested to prove themselves qualified before installed,and have to be maintained in time to ensure safety after installed. So, research anddevelopment of the test bench for the braking control units of metro vehicles is significant inorder to the actual need for production and transportation.This paper describes the classification of brake, the structure of the braking control unitsand the type of the braking control units. This paper analyzes the braking force calculationand distribution. This paper researches the principle of regenerative brake, resistor brake,electro-pneumatic brake, holding brake, emergency brake, fast brake, parking brake andanti-skid control function. The braking control units above are designed by China Academy ofRailway Sciences.The hardware design and selection of the test bench for the braking control units is thekey of this paper, and the software design and implementation of the test bench is too.The test bench is constituted according to computer test system. The test bench withindustrial computer as the core is connected with the braking control units by CAN interfacecard and is connected with PLC by RS485bus. The test bench is controlled by softwarerunning on industrial computer. It is configurable, has self-checking function. The test datacan be saved and printed.The software system of the test bench is composed of principal computer program andPLC program. The principal computer program consists of man-machine interface module,setup module, self-test module, test module and data management module. It is developedunder the VC++MFC application framework and keeps communication with PLC programby a custom protocol. The PLC program defines the data bits to be suitable for the physicaladdress mapping of PLC and modules input/output. This approach makes PLC and modulesonly have digital and analog conversion function. Logical control function is realized throughprincipal computer program.A large amount of field trials on the braking control units have been made after the testbench is completed, and some test data is given at last. The test bench is approved bycomparing experimental value with target value.