Intelligent valve positioner is the control unit for eletrictro-pneumatic valve. For intelligent valve positioner, valve position control algorithm plays one important role in valve lever postion and valve opening control. The conventional five contact switching control algorithm is characteristic of simplicity and rapid responding, but also blamed for difficulties of parameters adjusting and bad control robustness for different valve cores and travel distance. This paper developed a valve position control algorithm with the five contact switching and PID control strategies integrated. In this algorithm,the PID initial parameters were determined in the system initialization program and then were adaptively trimmed in the process of valve positioning control . The result of valve positioning control experiments showed that this adaptive control algorithm realized precise control of valve positions and met the requirement of positioning error below ± 1 % F. S.%智能阀门定位器是智能电气调节阀的控制核心,其中的阀位控制算法是实现调节阀阀杆位置精确定位和阀门开度精确调节的关键.传统的五接点开关算法具有算法简单、响应速度快的特点,但是存在参数调整困难,无法适应不同阀芯、不同行程调节阀精确定位的控制要求.为此将传统五节点开关控制与PID控制算法相结合,研究实现了一种阀位自适应控制算法.通过系统初始化程序实现了控制参数的初始整定并在阀位控制过程中实现了PID控制参数的自适应微调.阀门定位控制试验结果表明:该阀位自适应控制算法实现了阀位的准确控制,阀位定位精度满足±1％FS的设计要求.
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