A Study On The 2D Pneumatic Digital Servo Valve

With the extensive use of computer technology, the computer-based real-time control has become an important trend for pneumatic (hydraulic) control system. Compared with servo valve or proportion valve, the direct connection between digital valve and computer makes the D/A converter unnecessary. Besides, it also enjoys many other advantages, such as simpler structure, easier to manufacture, lower price, stronger anti-interference and anti-pollution abilities, smaller power requirement, more stable and reliable performance. Some foreign countries have already engaged in the production of series of digital valves. In China, however the study of digital valve is just underway. Thus the study of this paper is of important theoretical and practical significance.The two dimensional pneumatic digital servo valve (abbreviated as "2D pneumatic digital valve") discussed in this paper consists of a servo spiral mechanism, which simplified the conventional 2D pneumatic valve structure and enjoys great improvement in performance. Due to its closed loop structure, the capabilities of 2D pneumatic digital valve, such as its stability, rapidness, precision and rigidity restrict each other. Effects on the above mentioned performance indexes caused by changes of the structure parameters are neither linear nor identically progressive or degressive. Therefore, in order to improve the comprehensive performance of the 2D pneumatic digital servo valve, further studies need to be conducted about the relationships between its structure parameters and its static and dynamic features.Chapter One introduces the development of pneumatic transmission and control technology, the situation of digital control technology and pneumatic digital valve. It also introduces the background, significance and research content of this paper.Chapter Two mainly introduces in a detailed way the design plan of the 20 pneumatic digital valve, including the construction of the mechanical parts, operation principle, digital mechatronic transform components and digital control methods.Chapter Three introduces the establishment of mathematical model of the 2D pneumatic digital valve, including both the linear and nonlinear mathematical models.Chapter Four offers a study of the static features of the 2D pneumatic digital valve with the help of the emulation software MATLAB.Chapter Five offers a linear and nonlinear study of the dynamic feature of the 2D pneumatic digital valve with the help of the emulation software MATLAB.Chapter Six, based on the emulation experiment, decides on structural sizes, component design and process drawing of the 2D pneumatic digital valve.Chapter Seven offers a summary of the whole paper and points out places where further studies need to be made so as to provide guidance for the follow-up studies.