当测量温度等于设定温度时，程序返回温度设定模块，当测量温度不等于设定温度时，启动PID控制模块，然后返回测量显示模块，如此循环下去，直到测量温度等于设定温度为止。由于恒温箱温度控制系统具有大时滞和非线性特性，常规PID控制参数难以整定。在此设计了自整定PID算法，解决了PID整定困难的问题。下面介绍自整定PID算法的设计过程。

-When the measured temperature is equal to the set temperature, the program returns the temperature setting module, when the measured temperature is not equal to the set temperature, start the PID control module, and then return to measure the display module, so the cycle continues until the measured temperature equal to the set temperature is reached. As the incubator temperature control system with large time delay and nonlinearity, conventional PID control parameters tuning difficult. In this design, a self-tuning PID algorithm, PID tuning to solve the difficult problem. Here self-tuning PID algorithm design process.