下载后可任意编辑摘 要本设计能实现电热炉的恒温控制，文中详细介绍了 PID 算法的原理以及PLC、VB 等硬、软件的特性。在程序中利用 PID 算法对固态继电器输出占空比进行控制，铂电阻可进行温度采集并将采集到的温度数据和设定的温度值（目标温度值）进行比较，将比较结果输入到 PID 算式中，根据 PID 算式的输出结果来控制固态继电器的“通”、“断”，实现 VB 平台的上位机监控。 PLC 是一种具有较高性价比的工业现场设备，本设计使用了西门子公司S7-200 系列的 PLC，CPU221 模块、模拟量 EM231 模块。在 VB 窗体中，可以进行 PID 参数设定，我们可以看到温度变化的动态曲线图和设定温度的曲线，这两条线就能表现出很多现场信息，从而对 PID 参数进行优化整定，得到几组较好反映理想二次振荡曲线的数据，这几组数据使控制过程更加灵活、准确，从而使本系统适应不同的工业现场环境。关键词：PLC；VB；PID 算法；Prodave； AbstractThis design can achieve temperature control of the electric furnace, this paper describes the theory of PID algorithm and the features of PLC, VB hard, Software. I下载后可任意编辑PID algorithm is used to control the solid-state relay in the program. Platinum resistance collect temperature and compare the real temperature data with the temperature which is set (target temperature). And then give the results to PID algorithm, based on the output of PID algorithm, solid-state relay is controlled by the result of the "links" "broken", and monitor VB platform PC. PLC is a industrial equipment which is a high cost performance, This design uses PLC of Siemens S7-200 series, CPU221 module, Analog EM231 module.In VB form , the PID parameters can be set and it can be seen in the curves which discribe the dynamic changes of temperature and the curve of temperature setting. Showed lots of scene information, these two lines can optimize PID parameters, and then receive data which can reflect ideal quadratic curve oscillation . The...
