数字先导燃油计量滑阀无模型滑模控制研究

Non-modeled sliding mode control of a fuel metering spool valve with digital pilot stage

为提高传统电液伺服阀先导驱动燃油计量滑阀结构的可靠性与动态性能,提出一种数字阀阵列和节流孔组合先导驱动燃油计量滑阀的新构型。在深入分析燃油计量滑阀工作原理基础上,搭建其非线性数学模型,并基于滑阀位移实测数据对数字阀的流量系数进行辨识。不同占空比脉宽调制(PWM)信号下的阀芯位移仿真与实验结果基本一致,验证了模型的准确性,同时揭示了阀芯位移的振荡规律。幅频特性测试结果表明,该燃油计量滑阀在跟踪±50%全行程时的-3 dB幅频宽达到16.5 Hz。进一步地,提出一种不依赖于对象模型的无模型滑模控制算法,结果表明,在跟踪轨迹x=4.5sin(2πt)时,与PID控制相比,无模型滑模控制器的最大误差、平均误差以及误差的标差分别减少45.1%,15.4%,23.3%。

To improve the reliability and dynamic performance of a traditional fuel metering spool valve driven by a electro-hydraulic servo valve,a novel configuration of the fuel metering spool valve piloted by digital valve arrays and orifices was proposed,and its working principle was analyzed.Moreover,the nonlinear mathe⁃matical model of the entire valve was established,and the flow coefficient of each digital valve was identified by the measured data of spool displacement of the fuel metering valve.In addition,the accuracy of the simulation model was proved since the simulation results of spool displacement are basically consistent with the experimental results under pulse width modulation(PWM)signals with different duty ratios.The amplitude–frequency test re⁃sults indicate that-3 dB-frequency of the fuel metering spool valve can reach 16.5 Hz in the case of±50%full scale.Furthermore,a non-modeled sliding mode control(NMSMC)independent of the object model was pro⁃posed.The results show that when the tracking trajectory is x=4.5sin(2πt),the maximum error,average error and standard derivation of the error of the NMSMC are reduced by 45.1%,15.4%and 23.3%,respectively.