Study On The Dynamic Characteristics Of Pneumatic ABS Solenoid Valve For Commercial Vehicle

Along with the fast development of the automobile industry, the people's request to the automobile function is also more and more high, and it develops from the earliest stage of the automobile motive and cross-country request gradually to direction of economy, comfort and safety. For the anti-lock breaking system (ABS) can raise the stability, shorten the breaking distance and raise the safety in the manipulating process, it is a typical representative with the active security technology. So ABS is used widely in the automobile, and more and more people are engaged in studying it. But most researchers only pay attention to the development of arithmetic and logic, seldom to performance of actuators. Because the system of ABS is a kind of quickly-respond system, the dynamic characteristic of actuator is very important to the system, and decide that the high-powered control system can carry out or not. There- fore, the solenoid valve as the main execute component in ABS, its dynamic characteristic affects the whole work function of the ABS directly.Set out from the work principle of the baric ABS Solenoid Valve, this paper built up the mathematic model of its core. This thesis make sure the dynamic parameter when solenoid valve simulates the true in the model, and make the effect of electromagnetic characteris-tic, mechanical characteristic, baric characteristic of solenoid valve organically to unify. The thesis give the dynamic structure diagramof that model, and make use of the Matlab/Simulink to carry on imitate. At the same time it carry out dynamic imitate of the parameter about electric current, displacement of valve core, and analyse the result.Currently, the hardware in the loop (HIL) has become the popular one of modern design methods in the area of automobile electronics. This thesis applied the HIL to develop the test-bed of hardware in-loop simulation, and embed the actual hardware of the baric ABS to experiment pedestal. We designed the software, interface between software and hardware, drive electric circuit etc. In the end, we complete the test-bed of hardware in-loop simulation of Pneumatic ABS, thereby provide the test tool and the experiment platform for the research of control strategy and the development and research of the ABS pivotal parts of the system.That applied test-bed of hardware in-loop simulation of Pneumatic ABS to test the dynamic response and the change of empty share ratio and frequency is how to affect the dynamic response and its delay time of the valve. The paper adopt the methods of pulse width modulation (PWM) and pulse frequency modulation (PFM) when test dynamic respond characteristic of the valve, and give the formula that PWM and PFM compound when regulate. erify the dynamic imitate result of the valve in previous chapter, and show the respond delay time for the different brand electromagnetic valves when open and close.In the end, the paper discuss some factors that affect the response characteristic of the valve, such as: weight and displacement of valve core, magnetic length, number of winding, material of valve core etc. These datum provide theories for the design and structure amelioration of the solenoid valve. Some methods can be used to optimize the dynamic work process by choosing the high-quality magnetic material, reducing the weight of valve core, selecting the number of coil, minishing the displacement of the valve core, shortening the lengthof magnetic field, lowering the coil electric resistance, improving the electric drive circuit of the valve etc. Thereby the purpose that improve the dynamic response characteristic is achieved, followed with the design principle of the valve.The solenoid valve's dynamic imitate model and experiment conclusion set up in this text, are not only to the development of ABS, to the design of ECU but to the structure parameter of valve and the research of dynamic response characteristic all have certain instruct- ional significance. So this thesis can provide the theory gist for designing or amending structure parameter and evaluating dynamic characteristic of the valve.