The Study On Both Of A New Mini Pneumatic Servo Valve Based On The BMF And Its Control System

Saving energy, low power consumption, miniaturization, accuracy, high-speed and long life is an important developed direction in the pneumatic technology. Pneumatic servo valve is an important part in the Electric proportion / Servo Control system. Its function directly influence and even determine the whether the system can run regularly. As the development of an intelligent material --the SMA, developing a new pneumatic servo valve by using the driving feature of the SMA has become a new issue. This thesis presents the study on a new pneumatic servo valve, which is based on the driving feature of BMF(Bio Metal Fiber) that is a new SMA material. The whole thesis includes the design calculation, mathematical modeling, emulation study and control study of this new pneumatic valve based on the BMF.The introduction introduces the present situation and development of the SMA and the mini valve, analyzes the problem of the traditional pneumatic servo valve, and then presents a pneumatic servo valve based on the driving feature of the BMF, and defines the significance and the content of the study.The thesis describes the function of the BMF in detailed, compares to the general SMA, BMF possesses excellent driving function. Measures and verifies the parameters of the BMF through the experiment device, and collects the data and parameters that required in the thesis.After the deep understanding of the BMF, designs and calculates this new pneumatic servo valve based on the BMF. At first, designs and calculates the bias spring and cone valve, analyzes the force feature of the servo valve, when the core of the valve open and close, discusses the operational principle of this servo valve, and draw the 3-D model of the servo valve by CATIA, as the core of the cone valve is an important part in the servo valve, conducts finite element analysis of the stress and strain by the ANSYS.Then the thesis derivates the state equation of the new pneumatic mini servo valve.On this foundation, derivates the linear mathematical modeling and the transfer function of the new pneumatic mini servo valve by the method of theoretical analysis, also, analyzes the basic feature of the controlled object. Meanwhile, conducts a emulating analysis on the servo valve through the controlling strategy of the PID controller by utilizing the Simulink module which express the state equation.Finally, studies the SCM servo control system for the servo valve. The output signals of the press sensor and the flow sensor are send to the A/D to transformation and the data processing, the processed data are send to the controller AT89C52; meanwhile, these data should be compared with the pressure and the flow which are already set, and then obtains the deviation, gains the control values by the PID algorithm, by D/A transformation, realizes the opening of the valve by exerting the controlling voltage to BMF that is the driving component of the servo valve, thus achieves the control of the pressure and flow at the exit of the servo valve.Compare to the traditional pneumatic servo valve which is expensive and has complex structure, the characteristics of the new pneumatic servo valve based on the BMF include small volume, low price, simple structure, reliable function, and stable run, which is the innovation and the purpose of this thesis.