A Cost Effective Tracking System for Small Unmanned Aerial Systems

In this work we address the problem of object tracking in a largely unknown dynamic environment under the additional constraint of real-time operation and limited computational power. The main design directives remain that of real time execution and low price, high availability components. It is in a sense an investigation for the minimum required hardware and algorithmic complexity to accomplish the desired tasks. We present a system that is based on simple techniques such as template matching adapted for use in a dynamically changing environment. After development, the system was evaluated as to its suitability in a traffic monitoring application where it demonstrated adequate performance.     

Road Detection and Tracking from Aerial Desert Imagery

We present a fast, robust road detection and tracking algorithm for aerial images taken from an Unmanned Aerial Vehicle. A histogram-based adaptive threshold algorithm is used to detect possible road regions in an image. A probabilistic hough transform based line segment detection combined with a clustering method is implemented to further extract the road. The proposed algorithm has been extensively tested on desert images obtained using an Unmanned Aerial Vehicle. Our results indicate that we are able to successfully and accurately detect roads in 96% of the images. We experimentally validated our algorithm on over a thousand aerial images obtained using our UAV. These images consist of straight and curved roads in various conditions with significant changes in lighting and intensity. We have also developed a road-tracking algorithm that searches a local rectangular area in successive images. Initial results are presented that shows the efficacy and the robustness of this algorithm. Using this road tracking algorithm we are able to further improve the road detection and achieve a 98% accuracy.     

对象的交互测试与OATS正交阵列测试系统

对象交互测试是面向对象软件测试的一个重要环节。交互测试的重点是确保对象的消息能够正确传送。文章在完全测试不可能的情况下,提供了一种特殊的抽样方法———正交阵列测试方法OATS,从统计学角度指导“实验”以测试组件所有可能配置的子集,从而实现最少测试获得最高覆盖率。     

The Unmanned Aerial Vehicle Benchmark: Object Detection,Tracking and Baseline

International Journal of Computer Vision - With the increasing popularity of Unmanned Aerial Vehicles (UAVs) in computer vision-related applications, intelligent UAV video analysis has recently...     

Robust Observer-based Trajectory Tracking Control for Unmanned Aerial Manipulator

International Journal of Control, Automation and Systems - This paper aims at the stable motion control problem of the unmanned aerial manipulator (UAM) with internal interactions and external...     

空速/高度精确解耦跟踪控制研究及仿真

飞行器空速／高度的精确解耦跟踪,控制本质上是非最小相位输出精确解耦跟踪控制问题,由于存在内动态不稳定性,经典逆系统方法无法使用。将稳定逆办法与滑模控制相结合来解决存在的问题。首先针对稳定逆非因果性带来的问题,给出了一种稳定逆因果近似解的求法,经计算证明了近似结果误差的渐近收敛特性;然后利用稳定逆困果近似解将输出跟踪问题转化为不确定系统的鲁棒镇定问题,并对滑模控制和干扰观测器设计了相应的反馈镇定控制器。经过仿真表明综合稳定逆因果近似解和滑模控制的方案既发挥了逆系统方法的动态解耦能力,又利用了滑模控制的鲁棒性实现飞行器空速／高度精确解耦跟踪控制,也可以很好的兼顾控制器的鲁棒性和抗干扰性。     

微型扑翼飞行器的自适应位置跟踪控制器

微型扑翼飞行器是飞行器发展的重要方向,其位置跟踪控制成为该研究面对的首要问题.本文针对微型扑翼飞行器(flapping wing micro aerial vehicle,FWMAV)的位置跟踪控制问题展开研究,提出了一种可以避免控制系统陷入奇异且理论跟踪误差为零的自适应控制器.具体而言,首先提出了零梯度位置跟踪控制器.而后,理论分析表明其在解决FWMAV位置跟踪控制问题时存在局限性,即该控制器总是存在理论位置跟踪误差.为了弥补这一缺点,对零梯度控制器进行改进,提出了一种理论位置跟踪误差为零的自适应控制器,并利用非线性激励函数加快了位置跟踪误差的收敛速度.最后,仿真实验验证了该控制器的优越性.     

无人机仿真训练系统

为了满足无人机地面操纵人员的训练需求,以某新型无人机为应用背景设计并实现了一种“无人机仿真训练系统”,该文介绍了该系统的构成及其在计算机上的实现过程,并提出了运用小波分析的方法对飞行数据进行滤波。该系统集指挥控制、链路通信、飞控模块、任务载荷及视景显示于一体,重现了无人机操纵人员控制该新型无人机的全过程。对于训练操纵人员,该“无人机仿真训练系统”是一种缩短培训周期,减少费用,更为先进的训练方法。该系统的研制成功,对于提高训练无人机操纵人员的效率和扩大新型无人机的广泛应用具有重要意义。     

Trajectory Tracking Control of a Quadrotor Aerial Vehicle in the Presence of Input Constraints

International Journal of Control, Automation and Systems - In this paper, we address the control problem of a Quadrotor Aerial Vehicle (QAV) in the presence of the input constraints. For this...     

OATS: online aggregation with two-level sharing strategy in cloud

Online aggregation (OLA) is an attractive sampling-based technology to response aggregation queries by an approximate estimate to the final result, with the confidence interval becomes tighter over time. It has been built into the MapReduce-based cloud system for big data analytics, which allows users to monitor the query progress, and save money by killing the computation early once sufficient accuracy has been obtained. However, there is a serious limitation that restricts the performance of OLA that is the sharing issue of multiple OLA queries processing. Note that, in the original MapReduce paradigm, each query is processed independently without considering the potential sharing opportunities, leading to two major unnecessary additional execution costs: (1) the large redundant I/O cost, and (2) the replicative statistical computation cost. To eliminate such additional execution cost and improve the overall performance, we present online aggregation with two-level sharing strategy in cloud (OATS) based on MapReduce framework in this paper to effectively support online aggregation for large scale concurrent query processing in skewed data distribution. In the first-level sharing, we propose a sample buffer management mechanism to share the sampling opportunities among multiple OLA queries to reduce redundant I/O cost. While in the second-level sharing, we propose a heuristic algorithm (with a good scalability for large input) for the statistical computation to share partial statistics calculation to decrease the number of final aggregation operations, reducing the statistical computation cost. Based on such two-level sharing strategy, we have implemented OATS in Hadoop and conducted an extensive experiments study on the TPC-H benchmark for skewed data distribution. Our results demonstrate the efficiency and effectiveness of OATS.     

空中目标模拟系统设计

空中目标模拟系统,是为机载光电探测系统开展外场试验、研究建立的试验测试设备,本系统通过控制空中模拟目标的运动状态,建立一个较真实的半实物仿真试验环境,为光电探测系统对空中单目标或多目标的探测、截获、识别和跟踪等试验、研究提供条件.提出了该系统依据试验要求所应具有的功能,详细论述了设备的组成、技术指标,及该柔性控制系统的技术方案,并提出了该系统的关键技术.     

UAV中图像处理系统的研究

对UAV中的图像处理系统进行了探讨,给出了一个切实可行的图像处理系统,包括系统结构、硬件组成、软件设计等。其中,软件设计利用了Intel公司的开放源代码图像处理工具包OpenCV,并且在目标检测上取得了较好的效果。     

航空相机检测系统软件设计

为了检测航空相机工作是否正常,并可对有故障相机进行故障诊断,该文设计了一套自动测试软件系统。该系统能模拟飞机的任务管理系统与相机以ARINC429总线传输方式传输数据,并按相机记录信息的要求,提供时间、地速、高度等信息,以便控制相机的工作参数并记录相关信息,完成对航空相机性能的测试。     

基于视频的人体上半身运动跟踪系统

文章介绍了一个可以实时捕捉人体上半身运动的系统。该系统通过结合使用人脸检测、肤色检测和概率跟踪等技术,利用单个普通摄像头在一般的室内环境下跟踪人体的脸部和手臂关节位置。作为一个实时跟踪系统,该系统实现了跟踪的自动初始化以及自动从跟踪错误中恢复,并且在一定程度上处理光照变化、身体自遮挡等问题。该系统可以用于“虚拟现实”、“视频会议”、“基于摄像头的游戏”等一些领域中。     

Observer-based Adaptive Fuzzy Backstepping Tracking Control of Quadrotor Unmanned Aerial Vehicle Powered by Li-ion Battery

In this paper, an Adaptive Fuzzy Backstepping Control (AFBC) approach with state observer is developed. This approach is used to overcome the problem of trajectory tracking for a Quadrotor Unmanned Aerial Vehicle (QUAV) under wind gust conditions and parametric uncertainties. An adaptive fuzzy controller is directly used to approximate an unknown nonlinear backstepping controller which is based on the exact model of the QUAV. Besides, a state observer is constructed to estimate the states. The stability analysis of the whole system is proved using Lyapunov direct method. Uniformly Ultimately Bounded (UUB) stability of all signals in the closed-loop system is ensured. The proposed control method guarantees the tracking of a desired trajectory, attenuates the effect of external disturbances such as wind gust, and solves the problem of unavailable states for measurement. Extended simulation studies are presented to highlight the efficiency of the proposed AFBC scheme.     

基于DSP的运动目标跟踪系统

描述了一种以TMS320C6701数字信号处理器为核心的高速图像处理板和图像实时采集卡及摄像头构成的实时运动跟踪系统。在对采集的实时图像序列进行如十预处理后．采用了金字塔结构的图像存储方式和特征点跟踪算法埘运动目标进行跟踪．通过对特征点的运算得到目标运动的偏差怍为摄像头运动的参数,是后根据这些参数控制摄像云台持续跟踪运动目标的移动,最后还给出了在复杂背景下跟踪人体的实验结果。     

主动式太阳能追日系统设计

摘要：设计一种主动式太阳能追日系统。通过对太阳运行轨迹理论的分析和研究,确定了追日系统的天文算法公式,以保证系统的跟踪精度。在此基础上,针对追日系统的控制原理,提出了系统的控制方案,阐述了控制系统硬件电路的设计过程和软件平台的操作。经验证,设计的主动式太阳能追日系统的性能指标完全满足应用要求,运行稳定可靠,能适应各种复杂环境。     

点光源跟踪系统设计

本系统以TI公司的超低功耗MCUMSP430处理器为核心,CPU（MSP430）根据光敏电阻所反应的不同电压值经相应程序对两个步进电机进行控制,进而由步进电机带动激光笔进行左右和上下精确定位,实现对光源的跟踪并对检测电压进行实时显示。LM317典型恒流源电路实现LED电流在150～350mA范围内可调,从而调节LED灯光的强弱。整个系统很好的完成了规定范围内的点光源跟踪,并在光源亮度发生改变时具有较好的自适应性。