静脉输液过程中滴速自动控制系统的建模与仿真

Modeling and Simulation of an Automatic Drip Rate Control System on Intravenous Infusion Process

摘要:

为对静脉输液过程的滴速自动控制系统进行设计和分析,对此类型系统进行建模和仿真研究;通过实验数据拟合出输液过程的静态模型,进而得到非线性的动态模型；采用一阶惯性环节对执行机构的动态特性进行描述,采用定积分对基于红外光电对管的滴速检测环节进行建模；在静态工作点对过程模型进行基于增量法的近似线性化处理,对给定值小范围变化的情况设计了PID控制律,对给定值大范围变化的情况采用先开环控制后闭环控制的控制策略;仿真结果表明,该模型能较准确反映被控过程和控制系统的特性,对控制系统的实施有较好的参考价值。

Abstract:

To design and analyze an automatic drip rate control system on intravenous infusion process, this paper carried out researches on system modeling and simulation. A static model of the process, which was then used to calculate a nonlinear dynamic model, was obtained by experimental data after curve fitting. A first-order inertial element was utilized to depict the dynamics of the control element, while the infrared-photoelectric-based drip rate detection element was represented by a definite integral model. The process model was approximately linearized on quiescent operating points by incremental method, then a PID control law was designed for the case of small setting value changes while an open-loop-ahead closed loop strategy was presented for the case of large setting value changes. The simulation results showed the presented model could reflect the actual characteristics of the controlled process and control system, which was a good reference to implementation of the control system.