方管铝型材速度闭环控制等温挤压系统数值模拟
Numerical Simulation of Speed Closed-Loop Control Isothermal Extrusion System for Aluminum Alloy Square Tube

基于PID算法对闭环控制系统的挤压过程进行模拟，获得方管铝型材挤压速度和铝型材出模口温度控制系统的传递函数：$F_1\left(s\right)=\frac{410.142}{s？0.039}$ 以及挤压力与挤压速度控制系统的传递函数：$F_2\left(s\right)=\frac{176.183}{s？0.203}$ ，根据这两个传递函数设计的串级闭环控制系统，仿真模拟的铝型材出模口前后温差为6℃，符合等温挤压工艺要求。
Basing on PID algorithm, closed-loop control system applying to isothermal extrusion process was simulated. The transfer function describing correlation of extrusion speed and temperature for control system of square aluminum tube was obtained as followed: $F_1\left(s\right)=\frac{410.142}{s？0.039}$ The transfer function describing correlation of extrusion pressure and extrusion speed was obtained as followed: $F_2\left(s\right)=\frac{176.183}{s？0.203}$ . Through the closed-loop control system designed according to the two transfer functions, 6？C variation on die exit could be obtained during the simulation, which met the requirements of isothermal extrusion process.