Robust Adaptive Soft Landing Control of an Electromagnetic Valve Actuator for Camless Engines

This paper deals with a signal‐based robust adaptive approximation technique for a proportional derivative (PD) regulator which is applied to an electromagnetic valve actuator control for camless internal combustion engines. PD regulators generate very high spikes in the presence of unavoidable noise. These spikes cause high power dissipation and poor dynamic performance with a lack of precision. The presented method allows the reduction of the noise and not robust nonlinear uncertainties effects by using minimum variance analysis. The technique with which the PD regulator is approximated does not depend on the model of the controlled system. Hence, the technique is quite general and can be applied to any type of system. In addition, this paper describes a feasible real‐time self‐tuning of an approximated discrete PD regulator using a backward Euler technique. The main contribution of the paper is the presentation of an approximated PD controller using a minimum variance control strategy together with a weighted least squares method to adapt the parameters of this approximated controller. This control law realises a robust control technique with respect to the noise and nonlinear uncertainties. Moreover, a comparison with the approximate PD controller proposed in MATLAB by Mathworks is provided. The presented technique ensures a good dynamic performance, including low dissipation as well as accurate positioning and soft landing control.     

Adaptive Fuzzy PD+ Control for Attitude Maneuver of Rigid Spacecraft

In this paper, an adaptive fuzzy PD+ controller is proposed for the attitude maneuver of rigid spacecraft. The novel controller adjusts the gains of the PD+ attitude controller online according to attitude errors and angular velocity errors during the maneuver procedure. Therefore, quick response and avoidance of actuator saturation can be achieved simultaneously. Furthermore, the adaptation mechanism is designed, based on Lyapunov theory, to guarantee the stability of the closed‐loop system. To achieve good performance of the closed‐loop system under the constraint of actuator saturation, controller parameter optimization is developed on the basis of a genetic algorithm. Simulation results show that the transient performance and robustness against parametric uncertainty and environmental disturbance of the adaptive fuzzy PD+ controller are better than those of a constant PD+ controller.     

双积分系统阶跃响应快速无超调控制: 一种增益切换非线性PD控制

采用标准PD或PID控制器镇定双积分对象时,系统的阶跃响应必然存在超调:为此,设计了一种可以切换增益的非线性PD控制器,给出了系统阶跃响应无超调的充要条件,以及减小调节时间的方法.采用的切换规律是:当误差的幅值大于设定门限时,设计好的快速PD控制器投入工作,以加快误差的收敛:当误差的幅值小于设定门限时,设计好的强阻尼PD控制器投入工作,以抑制可能出现的超调.通过这两个控制器的配合作用,既能实现阶跃响应无超调,又能有效减小调节时间.仿真验证了该结论.     

机器人系统全局渐近稳定非线性PD+轨迹跟踪控制

采用一类具有“小误差放大、大误差饱和”功能的非线性饱和函数来改进常用的线性比例微分加（ＰＤ＋）机器人系统动力学控制,以形成非线性ＰＤ＋（ＮＰＤ＋）控制,从而获得更快的响应速度和轨迹跟踪精度．应用Ｌｙａｐｕｎｏｖ直接稳定性理论和ＬａＳａｌｌｅ不变性原理证明了闭环系统的全局渐近稳定性．两自由度机器人系统数值仿真结果表明了所提出的ＮＰＤ＋控制具有良好的控制品质．     

基于工业控制机的黄磷炉电极控制

本文设计采用工业控制机配以相应的板卡为硬件,Visual Basic和SQL SERVER 2000数据库软件作为编程的基础,运用带死区的PD和PID分离的算法,控制黄磷炉的电极,相对于现有的手动操作黄磷炉电极的生产方式,具有良好的人机交互能力,提高了生产效率和降低了生产能耗。     

Independent Hybrid Force/Motion Control of Constrained Six-Degrees-of-Freedom Manipulators

Controlling the dynamics of a constrained manipulator includesposition tracking as well as stabilization of the contact wrench.In this paper we derive a control scheme, that makes it possible to treat position and force control independently.The approach is based on a mass-orthogonal splitting of the space of joint torques, allowing independent actuation and therefore independent specification of control laws. An appropriate definition of the reference wrenchmakes it possible to achieve independent stability of the position and force loop.     

永磁同步电动机混沌系统的串级控制

根据永磁同步电动机的数学模型,研究如何运用串级PD控制器来控制混沌.首先在理论上运用劳斯(Routh)判据分析永磁同步电动机模型串级PD控制混沌的可行性,然后通过在平衡点处线性化的雅克比(Jacobian)矩阵来求取PD参数的值.最后在MATLAB/Simulink仿真平台上利用数值仿真实验验证其有效性.通过研究可知,运用串级PD控制可以较好地消除混沌使系统达到一个稳定的状态.该方法具有一定的参考实用性,为永磁同步电动机混沌运动分析或控制打下了研究基础.     

油纸屏障对变压器局部放电超高频检测信号的影响

受变压器内部复杂结构的影响,局部放电超高频信号在变压器内部的传播特性非常复杂。笔者通过变压器局部放电超高频实验研究,分析了油纸屏障对变压器局部放电被测超高频信号的影响。设计了油中气隙放电、油中沿面放电和油中电晕放电3种局部放电模型,在实验油箱中进行局部放电实验,采用超高频小环天线进行放电信号检测,在有无油纸屏障情况下获得了局部放电超高频信号实测数据,对所测局部放电超高频信号在时域和频域上进行了对比分析。结果表明,油纸屏障对超高频信号幅值衰减及信号功率谱有一定影响。     

基于医疗文本数据聚类的帕金森病早期诊断预测

针对多发于老龄人群的帕金森病（PD）的早期智能化诊断的问题，提出基于医疗检测文本信息数据的聚类技术来对PD进行分析预测。首先，对原始数据集进行预处理以获取有效特征信息，并通过主成分分析（PCA）方法将原始特征分别降维到8个不同维度的维度空间；然后，应用5个传统的经典聚类模型和3种不同的聚类集成方法分别对8个维度空间的数据进行聚类；最后，采用4个聚类性能指标来预测数据集中的多巴胺异常PD患者、健康体和无多巴胺缺失（SWEDD） PD患者。仿真结果显示，PCA特征维度值取30时，高斯混合模型（GMM）的聚类准确度达到89.12%；PCA特征维度值取70时，谱聚类（SC）的聚类准确度达到61.41%；PCA特征维度值取80时，元聚类算法（MCLA）的聚类准确度达到59.62%。对比实验结果表明，5种经典聚类方法中，PCA的特征维度值小于40时，高斯混合模型聚类效果最佳；3种聚类集成方法中，对于不同的特征维度，MCLA的聚类性能均表现优异，进而为PD的早期智能化辅助诊断提供了技术和理论支撑。     

变压器绕组特性对局部放电检测的影响

提出了一种利用绕组两端测量结果对视在放电量进行修正的方法.