基于模糊PID的低温环境试验系统控制特性研究

Control Characteristics of Cryogenic Environment Test System Based on Fuzzy PID

将模糊控制和增量式PID控制相结合,针对双调节阀协同工作的液氮蒸发制冷低温环境模拟试验系统,设计了一种模糊PID温度控制策略。通过开展预试验与系统辨识,确定了被控对象的状态空间模型,并在此基础上对试验系统的温度控制特性进行仿真研究。结果表明,和传统PID控制相比,模糊PID控制调节迅速、控制精度高。在此基础上,基于某实际试验系统开展了温度控制试验。试验和仿真结果证明,模糊PID方法在大型低温环境模拟试验系统温度控制中具有良好的精度和稳定性,该控制方法易于应用于同类试验系统,对相关应用中温度控制策略的设计具有指导意义。

By combining fuzzy control with incremental PID control,a fuzzy PID control system is designed for the liquid nitrogen refrigeration cryogenic test system with coordinated operation of double regulating valves. The state-space model of the controlled object is determined by the pre-test and the system identification,and the control system model is built for the simulation research. The simulation results show that compared with traditional PID control,the fuzzy PID control is faster in the adjustment time with better control accuracy. On this basis,experiments on a practical system are carried out to verify the feasibility of this method. Both the test and the simulation results prove the accuracy and stability of the control method,and such a method is easy to be transplanted to similar test systems,which is of guiding significance for the design of temperature control strategy in related applications.