The Studies And Applications Of Self-tuning Fractional-order Control In Loop System

High-speed wire-mill deploy loops between the stands to control the balance of metal flow and guarantee constant tension on wire in rolling process.Loop control are consisted of direct torque control of asynchronous electrical machine,loop height and tension decoupling control.The controllability of loop system is a significant part of the wire-mill and directly affect the quality of the wire.The high-speed mill requires the loop control system to work quickly and automatically.However,the traditional PID control cannot achieve precise control requirements.Since it is vital in high-speed wire production,it is of great importance to systematically analyze and research the loop control system.This paper is based on loop control system of #2 wire in Ansteel Group Wire Plant.In order to solve problems,including the dynamic overshoot,long response time and low steady state accuracy,of the traditional PID control method,this article completed in-depth research of how to improve the quality of loop control system in terms of control method as below:(1)We present the working process of high-speed wire-mill loop control and analyze and build the mathematical model of asynchronous electrical machine and loop control method.(2)We propose a improved grey wolf optimizer which shows high convergence and accuracy and avoids local optimum.(3)We introduce fractional-order control into the loop control system and make rational approximation available by using improved grey wolf optimizer.(4)We decouple the height and tension of the loop and run MATLAB simulation on it.The simulation shows that fractional-order control could automactically control the three parameter of the loop control system by system error,which is self-adjusting and of be better steady state and dynamic features compared to other traditional method.