基于模糊PID的流式细胞仪液流主从控制系统

液流系统两条主液路输出压力的平稳性、准确性是流式细胞仪功能实现的基础。针对传统液路输出压力同步性和准确性低的问题,提出通过模糊自适应PID算法对控制环中参数进行自整定的主从控制结构。根据气动控制元件动态模型与模糊控制器原理,构建主从闭环反馈控制系统,并利用Simulink对系统进行了建模,得到了不同控制信号及控制参数下系统的响应曲线。对响应曲线的分析结果表明,在流式细胞仪液流系统工作压力范围内,模糊PID控制的双液路主从系统的输出压力超调量降低8%,响应调整时间缩短1/2,同步误差小于1%,与传统PID控制的单液路相比,提高了系统压力输出的精度和稳定性。

Master-slave Control of the Flow Cytometer Flow System Based on Fuzzy Self-adaptive PID

The stability and accuracy of the output pressure of the double liquid path in the liquid flow system are especially important for the function of the flow cytometer. To improve the synchronism and the accuracy of the output pressure of the traditional liquid path, a master-slave control system based on the fuzzy self-adaptive PID algorithm to self-tune the parameters in the control loop is proposed. Based on the fuzzy control principle and dynamic models of the pneumatic control component, we establish a master-slave closed-loop control system which is further simulated by Simulink. The control parameters are adjusted, and consequently, the pressure-response curves of the system are obtained under different interference signals. The analysis of the response curves show that the output pressure overshoot is decreased by 8%, and the response time is decreased by 50%, and the synchronization error is less than 1% under the working pressure of the liquid flow system of the flow cytometer. Compared to single liquid path controlled by traditional PID, the master-slave double liquid path system controlled by fuzzy self-adaptive PID effectively improves the accuracy and stability of the output pressure of the system.