高精度气动比例压力阀设计与特性分析

Design and Characteristics Analysis of a High Precision Pneumatic Proportional Pressure Valve

设计了一种两级阀芯活塞式结构的以比例电磁铁为控制元件,采用电反馈闭环控制的高精度气动比例压力阀。该阀输出压力在0.6MPa内连续可调,且稳态精度可达0.25 kPa。建立了比例阀完整的非线性动态模型,分析了主要物理和几何参数对系统动态特性和控制性能的影响;构建了输出因子调整的模糊自适应比例加积分控制器,并利用ATmega16单片机实现了压力在设定范围内的快速高精度控制。实验结果表明,该阀在设计压力范围内具有良好的压力和流量特性;和传统PI算法相比,输出因子调整的模糊自适应算法在改善系统响应和控制稳定性的同时,显著提高了稳态控制精度,具有较高的效率和鲁棒性。

A high precision pneumatic proportional pressure valve was designed.The plunger-type structure with two-stage poppet was adopted for the valve.A proportional electromagnetic actuator was used as control component and the control method was electric closed-loop feedback.The output pressure can be adjusted continuously within 0.6 MPa absolute with the steady-state precision of less than 0.25 kPa.A completely nonlinear dynamic model was developed to analyze the effects of main physical and geometrical parameters on the valve＇s dynamic behavior and control performance. A self-adaptive fuzzy proportional plus integral controller with adjusting output scaling factor was designed for high precision and quickly control of different pressure target values, and carried out based on single chip- microcomputer ATmegal6. Experimental results indicated that the valve has a good performance in pressure and flow characteristics under the designed pressure. Compared to traditional PI controller, the proposed fuzzy algorithm can improve the response and control stability of the system as well as the steady-rate precision drastically, which has better efficiency and robustness.