呼吸机比例阀的控制与仿真

Modeling, simulation and control of proportional valve of ventilator

摘要:

比例阀是呼吸机吸气模块中负责流量控制的重要组件，为了研究比例阀的特性和提高呼吸机吸气模块的流量跟踪效果，推导了比例阀阀芯位移与流量之间的关系，构建了比例阀的被控对象模型并采用S-函数在Simulink中实现了该模型。对模型进行简单的输入控制可以获得比例阀的瞬态特征和稳态特征，对模型输入采用PID控制和模糊PID控制方法均能够提高比例阀的响应速度。在两种控制方法中采用一致参数，分别在Simulink仿真和实验条件下对比两种方法的流量跟踪效果，可以验证相较于固定参数的PID控制方法，模糊PID控制方法更能有效降低流量的超调量从而保持气路中流量的稳定。

Abstract:

Proportional valve is an important component responsible for flow control in the inspiratory module of the ventilator. In order to study the characteristics of the proportional valve and improve the flow tracking effect of the inspiratory module of the ventilator, the relationship between the displacement of the valve core and the flow of the proportional valve is deduced, and the controlled object model of the proportional valve is constructed, and the model is realized in Simulink by using S-Function. The transient and steady characteristics of the proportional valve can be obtained by simple input control of the model. The response speed of the proportional valve can be improved by PID control and fuzzy PID control. By using the same parameters in the two control methods, the flow tracking effect of the two methods is compared under the Simulink simulation and experimental conditions, which can verify that compared with the fixed parameter PID control method, the fuzzy PID control method can effectively reduce the flow overshoot, so as to maintain the stability of the flow in the gas path.