Research On The Programmable Pneumatic Proportional Pizeoelectric Valve

Some of the most important development trends in pneumatic technology are low power consumption,compact size. high-precision,high-speed and long service life. Electro-pneumatic proportional valve as the central element in electro-pneumatic proportional & servo control system, takes up an important position in pneumatic technology. Its performance can affect capability of the whole system directly. With the rapid development of proportional & servo control technology and piezoelectric ceramic,developing new-type electro-pneumatic valves that suit with the trends of pneumatic technology has become a very important task. The thesis mainly put the emphases on the performance of pneumatic proportional piezoelectric valve and programmable control on it. And,the thesis consists of six parts whose details are described as follows:Chapter 1 first describes the background of research on the pneumatic proportional piezoelectric valve,which is expatiated on several aspects including the electro-pneumatic proportional & servo control system, fluid piezoelectric drive & control, electro-pneumatic proportional valve's varieties and so on. Then it introduces the research situation of electro-pneumatic proportional valve,analyses the merits of this kind of valves that has been used in production presently,and predicts the developing trends of this kind of valves in the future. In the end, this chapter points out the significance and main content of the research work.Chapter 2 first states the jet-and-baffle principle.Then the chapter analyzes the piezoelectric jet-and-baffle valve's pneumatic characteristics and working principle.The piezo valve makes use of the Piezo effect:the Piezo-ceramic element bends on when a voltage is applied to it.At last,it discusses the valves' working principle.Chapter 3 analyzes the mathematic modeling of a HOERBIGER Type PS11193-B pneumatic proportional piezoelectric valve. On the one hand,based on a set of nonlinear differential equations,transfer function of the valve is derived by means of replacing-variable and linearization methods.According to the transfer function, we can find the system is a complex 4th-order system. On the other hand,a nonlinear dynamic model of the valve is formulated by modeling the valve's main internal mechatronic devices.Using Matlab, we establish the model and simulate the valve to obtain the best parameters for control.