The Research Of2D Digital Valve’s Dead-Zone Compensation And Its Embedded Controller

The electro-hydraulic servo system is widely used in the aerospace, shipbuilding, equipment manufacturing and other fields with the character of high density of power, fast dynamic response and large anti-load stiffness etc.2D-digital valve is one of the kinds of the electro-hydraulic control components, which is digital controlled directly. Because of its fast response, anti-pollution ability, high repeat precision, it has wide range of application and good prospects for development.The object of this paper is the2D-digital valve as well as2D-digital valve embedded controller.2D-digital valve structure and working principle was analyzed. According to its static flow characteristics, the nonlinear dead-zone was learned, and the high-frequency flutter dead-zone compensation mathematical model was built, analyzed and simulated. To get a better linearity of the flow characteristics, flow planning was put forward, and better linearity of the flow characteristics was get. As the core of2D digital valve electro-mechanical converter, a stepper motor was modeled and simulated. Then the2D digital valve embedded controller was designed, within stepper motor phase current’s closed-loop as well as the angular displacement closed-loop, and phase compensation to improve the bandwidth. Achieved the flutter dead-zone compensation and flow planning. Meanwhile, in order to be more safe and environmental, the power-down protection and low-power energy-saving mode was developed. There are also over-temperature protection, overcurrent protection.The details of the research and result are following:In chapter1, discussed the situation of the development home and abroad of the digital valve and its flow characteristics’research, as well as the development of the electro-mechanical converter. Also explained the puipose and significance of this paper.In chapter2, the2D-digital valve’s structure and working principle was analyzed. The concept of dead-zone nonlinear flutter compensation was proposed then had a discussion on its principle and its mathematical model was built. Another concept of nonlinear compensation-flow planning compensation was put forward. The flow planning compensation was elaborated on the mathematical principle of flow characteristics curve fitting.In chapter3, the model of2D digital valve electro-mechanical converter was made and simulated using Matlab and Simulink, concluding the second-order phase adjustment system. The controller’s bandwidth reaches280Hz at-900phase angle and300Hz at-3dB.In chapter4, the embedded2D-digital valve control system’s hardware and software was design.In chapter5, experimental study of low-power energy-saving mode and power-down protection. The embedded2D-digital valve controller’s bandwidth reaches240Hz. The2D-digital valve’s bandwidth reaches120Hz. Dead-zone flutter compensation can optimize the flow characteristic curve linearity. Without compensation the valves’linearity is7%,2%10%. Then after the flow planning compensation within dead-zone flutter compensation the flow characteristic curves’linearity is0.5%,0.8%,0.5%..In chapter6, all achievements of the paper were summarized and new prospect was put forward.