英语翻译Reading Material Tuning of the PID Controller The PID al

英语翻译
Reading Material Tuning of the PID Controller The PID algorithm is the most popular feedback controller used within the process industries.It has been successfully used for over 50 years.It is a robust easily understood algorithm that can provide excellent control performance despite the varied dynamic characteristics of process plant.Controller tuning involves the selection of the best values of Kc,Ti and TD (if a PID algorithm is being used).This is often a subjective procedure and is certainly process dependent.A number of methods have been proposed in the literature over the last 50 years.However,recent surveys indicate:(1) 30 % of installed controllers operate in manual.(2) 30 % of loops increase variability.(3) 25 % of loops use default settings.(4) 30 % of loops have equipment problems.A possible explanation for this is lack of understanding of process dynamics,lack of understanding of the PID algorithm or lack of knowledge regarding effective tuning procedures.This section of the notes concentrates on PID tuning procedures.The suggestion being that if a PID can be properly tuned there is much scope to improve the operational performance of chemical process plant.When tuning a PID algorithm,generally the aim is to match some preconceived “ideal” response profile for the closed loop system.The following response profiles are typical.
Often,with level systems exact setpoint following is not essential,hence proportional control is often used.Temperature loop dynamics can be slow because of process heat transfer lags.Dead-time is possible,especially in heat exchangers and temperature is not normally noisy.Consequently PID control is normally preferred.Flow loop dynamics are generally fast (of the order of seconds) .Control valve dynamics are normally the slowest in the loop.Flow systems are noisy.However,noise can often be dealt with simply by reducing the gain.

阅读资料调谐PID控制器的PID控制算法是最受欢迎的反馈控制器使用在加工工业.它已成功地用于已经超过50年.这是一个容易理解算法鲁棒性,可以提供良好的控制性能,尽管不同的动态特性的工艺厂.选择器调谐涉及到最好的价值观的Kc、钛和TD(如果PID算法被使用).这经常是一个主观过程程序和肯定是相互依赖的.大量的方法提出文学在过去的50年.然而,最近的调查表明:(1)30%的安装控制器操作手册.(2)增加30%的循环的变异性.(3)25%的循环使用默认设置.(4)30%的圈圈设备问题.这是一个可能的解释缺乏充分的认识过程动力学、缺乏了解的PID控制算法和缺乏知识对于有效调整程序.这部分的笔记集中PID调整程序.的建议被认为如果一个PID可适当调整在许多领域提高经营业绩的化学工艺厂.当一个PID控制算法调整,一般公认的目的是为了搭配一点“理想”反应分布闭环系统.下面的响应曲线的典型.
通常,与层次的系统设定的下面是准确不是必要的了,于是比例控制是常用的.温度循环动力学可以缓慢,因为传热过程的滞后效应.打印是可能的,尤其是在热交换器及温度通常不是吵闹.因此PID控制通常是优先考虑.流回路动态一般都是快(秩序的秒).控制阀动力学通常最慢的回路中.水流系统很吵.然而,噪声常常可以简单的通过减少处理增益.