热水器模糊PID水温控制系统的设计

Design of fuzzy PID water temperature control system for water heater

普通热水器放热水时,刚开始都会放掉一部分冷水,造成这部分冷水的浪费。设计了一种热水循环系统,可实现水龙头开启时即可得到设定水温的热水。该系统属于温度控制,温度具有非线性、大时变和大滞后的特点,使得控制方面存在精度不高、控制不灵敏、鲁棒性差的缺点。为了改善控制方面的不足,采用模糊PID算法设计了温度控制器,同时基于AT89C51单片机设计了硬件电路,通过实验得出,采用模糊PID算法实现温度控制时,控制精度高,动态特性好,鲁棒性好。

When the ordinary water heater releases hot water, some of the cold water will be released at the beginning. In this case, the cold water will be wasted. This paper designs a hot water circulation system which ensures that when the faucet is turned on, hot water with set water temperature can be obtained. However, the system is controlled by temperature, which is nonliterary, thus resulting into the imprecise controlling. In order to improve the controlling deficiency, the fuzzy PID algorithm is used to design the temperature controller. At the same time, the hardware circuit is designed based on AT89C51 single-chip microcomputer. It is concluded through experiments that when the fuzzy PID algorithm is used to realize temperature control, the control precision is high and the dynamic characteristics are good.