主动脉内血泵的全程滑模控制器设计  

Design of a global sliding mode controller for intra-aorta pump

作　　者：高斌[1] 谷凯云[1] 常宇[1] 刘有军[1] 

机构地区：[1]北京工业大学生命科学与生物工程学院,北京100124

出　　处：《医用生物力学》2011年第3期279-285,共7页Journal of Medical Biomechanics

基　　金：国家自然科学基金资助项目(10872013;11072012;31070754);北京市自然科学基金(3092005);北京工业大学人才强教深化计划--创新团队项目

摘　　要：目的为消除传统滑膜算法固有的抖震现象对控制器及被控对象的影响,使主动脉内血泵准确地响应人体的生理需求,本文设计了基于全程滑膜算法(global sliding mode controller,GSMC)的主动脉内血泵控制器。方法采用动态干扰补偿算法来估算主动脉内血泵控制系统的不确定性,并利用计算机仿真实验和体外循环实验来验证控制系统的动态特性和稳定性。结果由于通过动态干扰补偿算法估算系统不确定性,消除了滑膜算法固有的抖震现象。当系统设定流率为5 L/min时,系统的响应时间为80 ms,并且不存在超调和稳态误差。当控制器的负载转矩增加到0.4 N.m时,控制器的响应时间为25 ms。当输入一个搏动的流量信号作为控制系统的设定流率时,其动态响应时间为80 ms,流速最大误差为0.03 L/min。在体外循环实验中,由于实验中转速信号和流速信号的反馈频率低于理想情况,所以控制器的效果相比于计算机模拟有所下降。实验结果显示,当设定流率为5 L/min时,该控制器的响应时间是0.26 s,流率的误差为0.1 L/min。结论本文提出的控制器可以根据参考流量的要求准确地调节主动脉内血泵,并且对于系统的干扰和不确定性有良好的鲁棒性。由于动态干扰补偿算法的应用,算法的输出不存在抖震现象。Objective To design a global sliding mode control algorithm for the purpose of eliminating the chattering effect in conventional sliding mode control algorithm on both the controller and controlled plant from the conventional sliding mode control algorithm and regulating the intra-aorta pump in response to the demand of blood circulation system in human.Methods A dynamic disturbance compensator was used to estimate the uncertainty of the intra-aorta pump control system.Computer simulations and in vitro experiments were also conducted to verify the dynamic characteristics and robustness of the controller.Results As the dynamic disturbance compensator was used to estimate the uncertainty of system,the chattering effect in sliding mode control algorithm was eliminated.When the reference flow rate was set at 5 L/min,the response time was 80 ms without any overshot and static error.When the load torque of the controller was increased to 0.4 N·m,the response time was 25 ms.When the pulsatile signal was input as the reference flow rate,the dynamic response time was 80 ms with the maximum error of flow rate being 0.03 L/min.In the in vitro experiments,as the feedback frequency of flow rate signal and pump speed signal were lower than that in the ideal condition,the controller performance was deteriorative compared with computer simulation.The experimental results demonstrated that when the reference flow rate was set at 5 L/min,the response time was 0.26 s with the error of flow rate being 0.1 L/min.Conclusions The controller provided in this paper can accurately regulate the intra-aorta pump according to the reference flow rate.Furthermore,it has a strong robustness for the uncertainty and disturbance of the control system.Due to the use of dynamic disturbance compensator,the chattering effect of the algorithm has been eliminated.

关 键 词：主动脉内血泵 全程滑模算法 动态干扰补偿器 计算机仿真 血流动力学 

分 类 号：R318.01[医药卫生—生物医学工程]