用PID控制近似线性自抗扰控制

Approximation of linear active disturbance rejection control with PID control

中文关键词  线性自抗扰控制  PID控制  频域近似法  超前环节

英文关键词  linear active disturbance rejection control (LADRC)  PID control  frequency domain approximation  lead compensato

中文摘要

      线性自抗扰控制(LADRC)是结合PID和现代控制理论发展起来的新型控制方法, 很多文献表明PID可以转 化为LADRC, 那么LADRC能否近似为PID, 并且近似效果如何, 目前没有确定的答案. 本文首先证明LADRC的积分 作用实际上包含在扰动的估计及补偿里, 说明了二阶LADRC和PID的关系. 然后根据LADRC阶数的不同, 本文提出 了实际PID+n阶超前环节的策略近似各阶LADRC. 通过仿真实例, 说明二阶和三阶LADRC和转化后的PID具有相 似的抗干扰性能, 但更高阶的LADRC转换得到的PID控制效果不如LADRC. 因此, LADRC是PID控制在工业过程控 制中的推广, 具有更多的应用前景.

英文摘要

      Linear active disturbance rejection control (LADRC) is a new type of control method which combines modern control theory with PID control. It was shown that PID can be converted into LADRC in the literature, however, whether LADRC could be approximated with PID, and how the approximation is, is still unknown. This paper first shows that the integral function of LADRC is actually included in the estimation and compensation of the total disturbance, and further illustrates the relationship between second order LADRC and PID. According to the different order of LADRC, the strategy of practical PID + nth-order lead/lag compensator is proposed to approximate the LADRC. Simulation examples show that the second-order and third-order LADRCs have similar performance in disturbance rejection with the approximated PID respectively, but higher-order LADRC is better than the approximated PID. Therefore, LADRC is an extension of traditional PID and has a better application prospect in industrial process control.