基于模糊双线性模型的非线性系统的跟踪控制

研究一种基于T-S模糊双线性系统的跟踪控制器设计及稳定性分析.使用分布并行补偿法(PDC)设计了模糊控制器,得到模糊双线性系统跟踪控制渐近稳定的充分条件,仿真结果验证了该方法改进了闭环系统的性能.     

基于相位调制和线性滤波的多信道多功能光学微分器

多功能微分器可以满足光计算和光信号处理中的多种需求, 增强灵活性. 本文从理论上推导了一种基于相位调制和线性滤波的多功能光学微分器. 并在实验中, 将传输谱线近似为线性的光纤延时干涉仪(DI)和相位调制器级联, 得到了输入信号的两种微分结果. 通过调节DI的驱动电压调节其传输谱的漂移, 当光载波位于DI的传输谱线的谷值, 则获得信号的光场微分, 当光载波位于DI传输谱的线性斜率处, 则得到输入信号的光强微分. 通过分析各种微分的平均误差, 发现DI的线性度越高, 平均误差越小. 同时基于DI传输谱线的梳状特性,证实了多信道信号的同时微分.     

一种三坐标相控阵雷达的TWS算法

根据某三坐标相控阵雷达工作的特点,本文设计了一种Tws算法。该算法针对相控阵雷达变扫描周期的特点进行了适应性处理,针对不同目标模型状态变量不一致的问题进行了统一化的处理,并且在交互多模型算法中根据模型匹配程度动态调整模型的噪声协方差以达到更好的跟踪效果。该算法在雷达的实际跟踪试验中,取得了预期的效果。     

基于线性预测和加权投票的分块Mean-Shift行人跟踪算法

行人目标跟踪对公共交通规划、服务改善以及对大客流量的预测具有极重要的意义。而广泛采用的Mean-Shift算法及其改进算法在抗遮挡性能方面仍有非常大的改进空间。对此,文章针对行人轨迹交错或发生互相遮挡时可能引起的漏检及错检问题,结合基于分块的色调直方图、线性预测,提出了一种自反馈的混合检测方法。测试结果表明,该方法在行人发生遮挡或行径路线交叠时能够一定程度上减少错跟和漏跟,从而提高算法的鲁棒性。     

太阳跟踪自动化控制系统设计

随着太阳能不断被人类发现利用,如何应用自动控制系统有效捕捉太阳能更是当前自动化业界所面临的最新课题,本次设计就是利用自动控制技术实现了对太阳能的最大化合理应用。本系统阐述了自动化控制系统的设计过程以及软硬件部分的设计,系统采用AT89S52单片机作为整个系统的控制核心,系统采用了两种追踪模式：光电检测追踪模式和太阳角度追踪模式。晴天时系统采用光电检测追踪模式,而阴天时系统进入太阳角度追踪模式。在光电检测追踪模式下,光电检测部分采用光电二极管作为光电传感器,利用硬件装置通过光电二极管的比较电路来判断太阳的方位,从而达到了追踪太阳的目的。在太阳角度追踪模式下,要是通过软件计算当时当地太阳高度角和太阳方位角,再配合硬件来实现对太阳的追踪。系统的软件和硬件采用模块化设计思想,完成了系统的制作。     

基于I/Q支路相干积分观测滤波的GPS接收机信号跟踪方法

针对传统GPS接收机在弱信号环境下跟踪误差大,收敛速度慢的缺点,该文提出一种基于I/Q支路相干积分观测滤波的GPS信号跟踪方法。将接收机I/Q支路相干积分输出为观测量,应用无迹卡尔曼滤波(Unscented Kalman Filter, UKF)算法构建卡尔曼滤波器,得到基带数字信号处理滤波模型,闭合接收机跟踪环路。该方法能够有效减小传统GPS跟踪环路中信号参数的估计误差,提高接收机抗干扰能力和弱信号环境下环路跟踪性能。仿真对比结果表明,不同载噪比环境下相比传统GPS信号跟踪的方法,基于I/Q支路相干积分观测的信号跟踪算法能够提高跟踪精度,加快跟踪收敛速度。     

Heteronuclear decoupling by optimal tracking

The problem to design efficient heteronuclear decoupling sequences is studied using optimal control methods. A generalized version of the gradient ascent engineering (GRAPE) algorithm is presented that makes it possible to design complex non-periodic decoupling sequences which are characterized by tens of thousands of pulse sequence parameters. In contrast to conventional approaches based on average Hamiltonian theory, the concept of optimal tracking is used: a pulse sequence is designed that steers the evolution of an ensemble of spin systems such that at a series of time points, a specified trajectory of the density operator is tracked as closely as possible. The approach is demonstrated for the case of low-power heteronuclear decoupling in the liquid state for in vivo applications. Compared to conventional sequences, significant gains in decoupling efficiency and robustness with respect to offset and inhomogeneity of the radio-frequency field were found in simulations and experiments.     

基于LGJMS-GMPHDF的多机动目标联合检测、跟踪与分类算法

线性高斯跳变马尔可夫系统模型下的高斯混合概率假设密度滤波器(LGJMS-GMPHDF)为杂波背景下多机动目标跟踪提供了一种有效方法。该文将类别辅助信息引入LGJMS-GMPHDF,提出了一种密集杂波背景下多机动目标联合检测、跟踪与分类算法。该算法在LGJMS-GMPHDF中用属性向量扩展单目标状态向量,用位置和属性的组合测量似然函数代替单目标位置及杂波位置测量似然函数,提高了不同类目标与杂波测量间的鉴别能力,进而改善了目标数目及状态的估计精度;在更新目标状态的同时,对目标属性信息进行更新。该算法实现了时变数目的目标状态和类别估计。杂波背景下交叉和临近并行机动目标的跟踪实验验证了该文算法的联合检测、跟踪与分类性能。     

机载相控阵雷达TAS方式的实现

相控阵雷达具有灵活的波束指向、驻留时间、可控的空间功率及时间资源分配等特点,使相控阵雷达具有支持跟踪加搜索(TAS)的能力,即能同时完成搜索和对多个目标的精密跟踪。该文从任务调度机制和跟踪滤波两项关键技术论述了机载相控阵雷达TAS方式的算法。通过计算机仿真验证,表明这种方法能够使相控阵雷达具有很好的跟踪加搜索(TAS)能力。     

A method for characterising solids translational and rotational motions using Multiple-Positron Emission Particle Tracking (Multiple-PEPT)

Solid motion can be classified into translational motion and rotational motion; both play an important role in a wide range of engineering processes. While translational motion has been extensively studied in various systems, there is a lack of information on rotational motion, possibly due to a lack of appropriate experimental techniques. For a number of mixing processes involving heat transfer for solid–liquid mixtures, the heat transfer coefficient between solid and liquid is critical in determining process times and overall product characteristics, and is greatly dependent on both rotational and translational behaviours of the solids, which ideally need to be studied simultaneously. This paper presents a new technique, Multiple-Positron Emission Particle Tracking (Multiple-PEPT), which can follow multiple particles simultaneously through a considerable thickness of surrounding material. Both translational and rotational motions of the solid can be reconstructed. The accuracy of the method for the translational velocity was better than 10% while for the angular velocity 23% for speeds up to 0.25 m/s. Multiple-PEPT will therefore offer the possibility to study translational and rotational motions for a range of engineering systems. The potential applications of tracking solid translational and rotational motions are illustrated by an example of tracking a cubed potato in a rotating can.