Study And Development Of ABS Testing-Control Experimental & Teaching System

Based on MK20-I ABS (Anti-lock Brake System) of Santana 3000, the thesis introduces ABS testing-control experimental and teaching system through the design and development of software and hardware, it aims to design a set of ABS testing-control experimental system without affecting the performances of ABS.The system is composed of hardware and software. The sensor, personal computer and data acquisition card are taken as core device; signal processing circuit and ABS testing-control bench are matched. The software consists of two parts: application program and hardware driving program. Application program is used for gathering, demonstration, printing and hardware driving program mainly completes working pattern setting of data acquisition card.In the department of hardware design, the design of ABS experimental bench, signal processing circuit, testing-control board and data acquisition system are described in great detail in the article. The paper points out the method to simulate vehicle's braking situation under different velocity condition by three-phase asynchronous motor, and the structure drawing of ABS testing-control bench is designed by CAD2007 after the intensity examination to the axle. According to the characteristic of signals out from sensors, the paper has accomplished the design of signal processing circuit of wheel speed, pressure and solenoid valve. The corresponding simulation and the practical application show that the circuit is reliable. In the design of ABS testing-control board, according to the number of wheel-speed pulse counted by AT89C2051SCM, wheel speed is computed, and it is demonstrated by MAX7219 actuating common cathode nixie-tube. In the unit of fault settlement, 6 usual faults of the sensor and hydraulic pump are realized by two-row and two-grade switch.In the design of software department, taking LabVIEW as software development platform and applying virtual instrument and object-oriented analysis design method, the main control module, login module, auxiliary module and data acquisition analysis module are designed in this paper. Wheel speed, reference speed, retarded velocity, slipping ration, braking pressure can be measured in data acquisition system timely, the function such as the analyses of data stream, the print and store of waveform, the data processing after testing can be realized. The block diagram of braking pressure, wheel speed, reference vehicle speed, retarded velocity and slipping ration are designed in this article.Finally, debug each module of the system on the spot, the result indicates that the system is in good condition, it owns many advantages such as: friendly man-machine interface, easy ways to operate and good dependability, etc. Being able to be applied on different occasions, for example, experiment, teaching, it turns out to have wide practical value and prospect. The system has fulfilled the demand of the design objectives.