径向柱塞泵电液比例排量的模糊积分复合控制

在液压控制系统中,采用传统的PID控制策略难以达到高精度的要求。本文提出一种模糊-积分复合控制策略,大偏差时采用模糊控制,小偏差时采用积分控制,由此构造的控制器满足液压系统响应速度快,超调小,没有稳态误差的要求。     

Best Tracking Performance under Plant Uncertainty and Control Energy Constraint

This paper has investigated best tracking performance for linear feedback control systems in the case that plant uncertainty and control effort need to be considered simultaneously. Firstly, an average integral square criterion of the tracking error and the plant input energy over a class of additive model errors is defined. Then, utilizing spectral factorization to minimize the performance index, we obtain an optimal controller design method, and furthermore study optimal tracking performance under plant uncertainty and control energy constraint. The results can be used to evaluate optimal average tracking performance and control energy in designing practical control systems.     

Layered Multi-mode Optimal Control Strategy for Multi-MW Wind Turbine

The control strategy is one of the most important renewable technology, and an increasing number of multi- MW wind turbines are being developed with a variable speed-variable pitch （ VS-VP ） technology. The main objective of adopting a VS-VP technology is to improve the fast response speed and capture maximum energy. But the power generated by wind turbine changes rapidly because of the continuous fluctuation of wind speed and direction. At the same time, wind energy conversion systems are of high order, time delays and strong nonlinear characteristics because of many uncertain factors. Based on analyzing the all dynamic processes of wind turbine, a kind of layered multi-mode optimal control strategy is presented which is that three control strategies： bang-bang, fuzzy and adaptive proportional integral derivative （PID） are adopted according to different stages and expected performance of wind turbine to capture optimum wind power, compensate the nonlinearity and improve the wind turbine performance at low, rated and high wind speed.     

水平轴风力机变桨载荷分析与计算

针对风力机变桨载荷常规计算时忽略很多细节从而导致数值不精确的问题,文中以大型水平轴风力机为研究对象,通过数值计算软件Matlab/Simulink,在建立风电机组非线性模型基础上,对风力机桨叶外形参数和空气动力数据进行分析和计算,得到风力机桨叶轴向诱导因子、周向诱导因子、入流角、攻角、相对风速、桨距角等参数对应不同风速的值,最终根据这些参数,综合分析计算,得到了风力机变桨载荷的数值.计算结果为风力机变桨控制系统分析和设计提供了更为可靠的基础性数据.     

采煤机调高泵隐半马尔可夫模型磨损故障预测

针对采煤机调高液压系统中调高泵故障很大程度依赖于设计者和用户的知识和经验水平,提出一种基于隐半马尔科夫模型（Hidden Semi-Markov Model,HSMM）的故障预测方法。首先,对采煤机调高液压系统中调高泵压力、流量,调高油缸活塞杆速度、位移进行时域分析。然后,通过对特征值进行K-均值聚类分析确定隐状态数。最后,通过MATLAB和Python编程实现调高泵HSMM故障预测。结果表明：与基于隐马尔可夫模型（Hidden Markov Model,HMM）预测方法相比,调高泵早期故障、后期故障和灾变故障测试样本的预测结果识别率分别提高了10%、5%、20%,基于HSMM的调高泵磨损故障预测方法具有可行性。     

凸轮转子泵送系统机电液复杂工况下流量输出特性

针对凸轮转子泵送系统的机电液复杂工况及流体的物性参数对泵输出流量影响规律尚不完全明确这一问题,在凸轮转子泵三维建模的基础上,给出泵径向间隙、电机转速、流体浓度、泵进出口压差4个影响因素的变化范围,采用计算流体力学模型进行参数化研究,分析在单因素、多因素影响下的变化规律。结果表明:泵径向间隙(0.16～0.24 mm)、电机转速(200～600 r/min)、流体浓度(50%～100%)、泵进出口压差(0.2～0.6 MPa)对泵输出流量分别有增大或减小作用,且存在相互促进或抑制关系;在多因素变量共同作用下,泵输出流量变化规律愈发呈现复杂性和多样性。