基于模糊控制的螺杆挤出机温度控制系统设计

Design of Temperature Control System for Screw Extruder Based on Fuzzy Control

以螺杆挤出机温控系统的扰动多、非线性、时变以及大滞后的特性,研究得到了智能化的控制算法,对于现场无法充分预料的情况,这种温度控制系统能够发挥重要的作用。使用Zig Bee无线传感技术可实现温度监控的远程操作,提升检测效率和水平。对远程无线温度控制系统的硬件系统进行了设计,对CC2430射频主控芯片的外围电路、温度传感电路以及温度控制电路进行设计。针对螺杆挤出机温度控制系统进行实例分析,研究结果表明:使用常规PID控制器,在阶跃信号和脉冲干扰信号作用下,系统超调量和稳定时间不能够满足螺杆挤出机温度控制的要求。使用模糊PID控制器,相比常规PID控制器的超调量和稳定时间要明显增强。以尼龙6/Ca Cl2复合材料挤出为例,分别使用常规PID控制算法和模糊控制算法进行对比分析,研究温度控制精度对产品成型质量的影响。在模糊控制算法下,三种产品(温度设置分别为240,260,280℃)的缺口冲击强度合格率比较使用常规PID控制算法时提高了6.87%,弯曲应力合格率、断裂伸长率合格率、拉伸强度合格率分别提高了8.67%,9.33%,8.77%。

Many disturbances,nonlinear and time-varying and large time delay characteristics of the temperature controlsystem in extruder screw,intelligent control algorithm has been studied,the temperature control system for the site cannot be fullyexpected to play a very important role.ZigBee wireless sensor technology can be used to realize the remote operation of temperaturemonitoring and improve the detection efficiency and level.The hardware system of the remote wireless temperature control systemwas designed,and the peripheral circuit,temperature sensing circuit and temperature control circuit of the CC2430RF maincontrol chip were designed.The screw machine temperature control system of extrusion was analyzed,the results show that the useof conventional PID controller,the step signal and pulse interference signal,the system overshoot and settling time cannot meetthe requirements of temperature control screw extruder.Using the fuzzy PID controller,the overshoot and the settling time weresignificantly enhanced compared to the conventional PID controller.Taking nylon6/CaCl2composite extrusion as an example,the conventional PID control algorithm and fuzzy control algorithm wre compared and analyzed respectively,and the influenceof temperature control accuracy on the quality of product forming was studied.In the fuzzy control algorithm,the notched impactstrength of three kinds of products(temperature settings were240,260,280℃)pass rate compared with the conventional PID controlalgorithm was increased by6.87%,the passing rate of bending stress,elongation at break and tensile strength increased by8.67%,9.33%,8.77%separately.