基于预测模型的分段模糊控制系统设计

摘要

针对加速量热仪需要按照材料的特性设定温度变化规律,温度精确控制困难的问题,通过研究电加热功率与温度变化的关系,采用调整脉冲宽度调制方波(PWM)占空比的方式来控制加热功率.针对系统的非线性、时变性、变结构、多层次和滞后等缺点,提出分段、分级和基于预测模型的模糊控制策略.采用上位机(IPC)+下位机(PLC)的测控系统结构,并编写PLC程序完成模糊控制.实验结果表明,本方案实现了以固定升温速率加热,定点温度保持的功能.%Due to the demand of accelerating rate calorimeter (ARC), the heating rate should be varied according to the characteristics of the testing materials, and the temperature control should be precise, but difficult, the method of changing the duty cycle of pulse width modulation (PWM) was used to change the power of the heating system based on the research of the relationship between the electrical heating power and temperature variation. Taking into consideration the characteristics of nonlinearity,time-varying,variable structure,multi-level and long time delays,a temperature control system was developed which combined the dynamic sectional fuzzy control with fuzzy control strategies generalized from the prediction mode. The hardware of the control system was designed with Industrial Personal Computer (IPC) and Programmable Logic Controller (PLC) and the fuzzy algorithm programs were complied by PLC. Testing results show that the control system meets the demand.