受限工作模式下航迹融合多目标跟踪算法研究

针对实际目标跟踪系统中，传感器工作常常受到限制，以满足跟踪精度和隐蔽性双重 要求的工程应用问题．研究了杂波环境下，采用红外(主传感器)始终工作、雷达(辅传感器) 间歇工作的特殊传感器工作模式，红外\雷达双传感器航迹融合多目标跟踪算法及实现．仿 真表明可以达到跟踪精度与隐蔽能力兼顾的系统要求．     

一种新的区域种子填充算法

在未知边界的区域种子填充算法中,改进扫描线算法犤1犦具有非常高的填充效率,但它只适用于四连通区域,为此,文章提出了一种新的基于边界跟踪的填充算法,该算法弥补了文献犤1犦算法的不足,可以填充任意的四连通或八连通区域,而在填充效率上仅比其略低几个百分点,因此更具有实际应用性。     

基于双摄像机的视频特征跟踪算法研究

在视频动画中，特征跟踪结果决定了三维重建的运动信息是否逼真。提出一种基于双摄像机的视频特征跟踪算法，它采用卡尔曼滤波预测特征点的位置，然后利用子块模型进行特征匹配，最后利用极线方程指导跟踪和剔除跟踪误差大的特征点。该算法已经用于我们开发的VBHA系统中，实验结果表明，其速度和效率能够满足视频动画的要求，并且能够部分解决自遮挡的问题。     

一类具有不确定的互联大系统分散鲁棒输出跟踪控制器设计

针对一类具有不确定的互联大系统，研究了使受控系统鲁棒稳定和渐近跟踪参考输入的分散鲁棒跟踪控制器的设计问题，并对具有分散反馈控制器的闭环大系统，给出了其鲁棒稳定以及渐近跟踪的证明。     

智能化多通道钢管超声波自动探伤系统的开发与应用

分析了计算机进行管理的超声波自动探伤系统的检测原理和系统组成以及在焊管生产中的应用状况，该系统统采用智能化探伤技术，实现了在线检测、探头跟踪、闸门设置等功能，肯定了其具有自动化程度高、抗干扰能力强、探伤准确率高及系统稳定可靠等特点。     

Using Multiple-Hypothesis Disparity Maps and Image Velocity for 3-D Motion Estimation

In this paper we explore a multiple hypothesis approach to estimating rigid motion from a moving stereo rig. More precisely, we introduce the use of Gaussian mixtures to model correspondence uncertainties for disparity and image velocity estimation. We show some properties of the disparity space and show how rigid transformations can be represented. An algorithm derived from standard random sampling-based robust estimators, that efficiently estimates rigid transformations from multi-hypothesis disparity maps and velocity fields is given.     

Visual Navigation in Natural Environments: From Range and Color Data to a Landmark-Based Model

This paper concerns the exploration of a natural environment by a mobile robot equipped with both a video color camera and a stereo-vision system. We focus on the interest of such a multi-sensory system to deal with the navigation of a robot in an a priori unknown environment, including (1) the incremental construction of a landmark-based model, and the use of these landmarks for (2) the 3-D localization of the mobile robot and for (3) a sensor-based navigation mode.For robot localization, a slow process and a fast one are simultaneously executed during the robot motions. In the modeling process (currently 0.1 Hz), the global landmark-based model is incrementally built and the robot situation can be estimated from discriminant landmarks selected amongst the detected objects in the range data. In the tracking process (currently 4 Hz), selected landmarks are tracked in the visual data; the tracking results are used to simplify the matching between landmarks in the modeling process.Finally, a sensor-based visual navigation mode, based on the same landmark selection and tracking, is also presented; in order to navigate during a long robot motion, different landmarks (targets) can be selected as a sequence of sub-goals that the robot must successively reach.     

Global tracking control of underactuated ships by Lyapunov's direct method

This paper studies the global tracking problem for an underactuated ship with only two propellers. Under sufficient conditions of persistent excitation, two constructive solutions are proposed by application of Lyapunov's direct method. Both solutions exploit the inherent cascade interconnected structure of the ship dynamics and generate explicit Lyapunov functions. A common feature of the second solution and the recent cascade approach of Lefeber (Tracking control of nonlinear mechanical systems, Ph.D. Thesis, University of Twente, 2000) is that global exponential tracking is achieved, but at the expense of transient performance. Extension to unmeasured thruster dynamics is also considered. Simulation results validate the proposed tracking methodology.     

Tracking in a class of nonminimum-phase systems with nonlinear internal dynamics via sliding mode control using method of system center

A method of asymptotic output tracking in a class of causal nonminimum-phase uncertain nonlinear systems is considered. Local asymptotic stability of output tracking-error dynamics are provided for the specified class of systems with the nonlinear hyperbolic at the origin internal dynamics forced by a reference output profile and external disturbances defined by a known linear exosystem. The nonlinear vector field of the internal dynamics is expanded in a power series, obtained at a selected operational point in the internal dynamics state space. The presented technique employs some linear algebraic methods and sliding mode control approach. The solution is a complete constructive algorithm.     

A method of detecting and tracking irises and eyelids in video

We locate the eye corners, eyelids, and irises in every frame of an image sequence, and analyze the movements of the irises and eyelids to determine changes in gaze direction and blinking, respectively. Using simple models for the motions of the head and eyes, we determine the head-independent motions of the irises and eyelids by stabilizing for the head motion. The head-independent motions of the irises can be used to determine behaviors like saccades and smooth pursuit. Tracking the upper eyelid and using the distance between its apex and the center of the iris, we detect instances of eye closure during blinking. In experiments on two short image sequences, in one of which the subject was wearing glasses, we successfully located the irises in every frame in which the eyes were fully or partially open, and successfully located the eyelids 80% of the time. When motion information in the form of normal flow was used, the irises were successfully tracked in every frame in which the eyes were fully or partially open, and the eyelids were successfully located and tracked 90% of the time.