| Anti-lock braking system (ABS) is the standard configuration in vehicles,wherein ABS relay valve is the main actuator of ABS in commercial cars, trucks andtrailers, the performance of which concerns the security of users’ lives andproperties. So, it is desirable and also important to develop a testing system that isefficient and stable.This paper developed a nonlinear dynamic model of ABS relay valve, and itscharacteristics were simulated. Finally, by using the developed testing system, anABS relay valve was tested. The thesis is divided into the following five sections:(1) Structure of ABS relay valve and its work theory were analyzed. Thissection provided a theoretical basis for the development of dynamic model.(2) A mathematical model of ABS relay valve was set up and its dynamiccharacteristics were simulated. Some influencing factors to the valve’s dynamiccharacteristics, such as the voltage, the coil circle number, resistance, air gapbetween fixed core and spool were analyzed. The simulation results show thatdifferent driving voltages, coil circle numbers, resistance and air gap can lead todifferent lag times, which influence ABS relay valve performances.(3) The main dynamic characteristics of ABS relay valve include responsecharacteristics, regulation characteristics and residue characteristics. The testingitems and specific testing program according to these three characteristics wereidentified. The system principle and pneumatic system were designed. This paperdesigned a set of ABS relay valve controller, which can receive data from PCthrough a serial port. And its control accuracy is in microsecond.(4) The testing software was designed. The main work of the software includesconfiguring the acquisition card, controlling the clamping, sending test parametersthrough serial port, calculating the value of the feature points, calibrating the sensorsand so on.(5) At last, an ABS relay valve was tested by using the new testing system. Theresults show that the testing system developed in this paper can be used for rapid testing of ABS relay valve. The results show that, in the continuous adjustment state,ABS relay valve’s regulation speed is faster than ABS regulator.This paper reached the design requirements, and the testing system has beenused in production practice, and provided a high efficient means for testing ABSrelay valve. |
