The effects of platform motion and target orientation on the performance of trackball manipulation

The trackball has been widely employed as a control/command input device on moving vehicles, but few studies have explored the effects of platform motion on its manipulation. Fewer still have considered this issue in designing the user interface and the arrangement of console location and orientation simultaneously. This work describes an experiment carried out to investigate the performance of trackball users on a simple point-and-click task in a motion simulator. By varying the orientation of onscreen targets, the effect of cursor movement direction on performance is investigated. The results indicate that the platform motion and target orientation both significantly affect the time required to point and click, but not the accuracy of target selection. The movement times were considerably longer under rolling and pitching motions and for targets located along the diagonal axes of the interface. Subjective evaluations carried out by the participants agree with these objective results. These findings could be used to optimise console and graphical menu design for use on maritime vessels.

Statement of Relevance: In military situations, matters of life or death may be decided in milliseconds. Any delay or error in classification and identification will thus affect the safety of the ship and its crew. This study demonstrates that performance of manipulating a trackball is affected by the platform motion and target orientation. The results of the present study can guide the arrangement of consoles and the design of trackball-based graphical user interfaces on maritime vessels.     

Fundamental properties and performance of conventional bearings-only target motion analysis

This paper considers the problem of estimating the position and velocity of an object from noise corrupted bearing measurements obtained by a single moving observation platform. The process is inherently nonlinear and exhibits unusual observability properties that are geometry-dependent. A maximum likelihood estimate (MLE) of the target motion analysis solution is developed and its performance analyzed. A comparison is drawn between the MLE and two previously reported methods, a nonlinear modified-instrumental variable estimate (MIV) and the pseudo-linear estimate (PLE). Both the MIV and PLE are shown to derive from approximations to the nonlinear measurement equation and therefore share some common properties with the MLE. The limits on performance that can be expected from processing bearing data are detailed. Specifically, for long range-to-baseline geometries, approximate expressions for the Cramer-Rao bound are derived. Extension of the results to the practical filters approximately predicts numerically observed behavior. For less restrictive geometries, bounds are presented. Incorporation of a target speed constraint on the MLE results in a transition to a lower dimensional problem as noise level and range increases. Monte Carlo experimental results are presented and the improvements realized by the MLE techniques are evident.     

Investigating the effects of business process orientation on organizational innovation performance

Business process orientation (BPO) supports business process management by reorienting employees’ focus from functional performance to customer value adding. While it is generally believed that BPO improves various aspects of organizational performance, there has been a lack of empirical evidence. The results of this study showed that BPO significantly influences organizational innovation performance and identified the underlying mechanism for the effect. Interestingly, it is found that a process view is not sufficient to enhance organizational innovation performance. Cross-functional integration may also need to be carefully managed for innovation. These findings improve the current understanding of BPO and offer managerial suggestions for enhancing innovation.     

Effects of handle angle and work orientation on hammering: I. Wrist motion and hammering performance

This research investigated the range of wrist motion characteristics associated with the ergonomic principle of "bending the tool and not the wrist" as applied to the hammer. It is thought that bending the tool reduces angular wrist motion, which has been shown in the literature to be a risk factor in hand/wrist disorders such as carpal tunnel syndrome and tenosynovitis. Hammer handles angled at 0 (straight), 20, and 40 deg were investigated in this study. For novices, hammer handles bent at 20 and 40 deg resulted in less total ulnar deviation than straight hammers. However, there was a trade-off in beginning and ending positions of the wrist in that the angled hammers reduced ulnar deviation at the impact position but increased radial deviation at the starting position of a hammer stroke. Handle angle did not significantly affect hammering performance. Wrist motion was affected minimally by hammering orientation, but hammering performance was significantly worse in the wall orientation compared with the bench orientation. This research suggests that for novice users, hammers with handles bent in the range of 20 to 40 deg could possibly decrease the incidence of hand/wrist disorders caused by hammering.     

Research of trackball based on MEMS gyro

为解决精密球体在研磨过程中的研磨轨迹无法测量等问题,将MEMS陀螺仪测量角速度技术应用到球体研磨轨迹的测量中,研究并实现了一种基于MEMS三轴陀螺仪和STM32微控制器的轨迹测量系统.介绍了ITG3200三轴陀螺仪的特点、原理以及轨迹测量系统方案设计;分析了温度影响陀螺仪零偏的机理,基于最小二乘法原理,建立了零偏补偿模型,有效地提高零偏稳定性,满足了工程需要.进行轨迹测量系统的双自转研磨实验,结果表明:双自转研磨方式研磨均匀性较好.     

基于运动目标检测技术的研究

运动目标检测的目的是在序列图像中将变化区域从背景图像中提取出来,因此如何将运动目标进行有效的分割对后期目标跟踪处理等行为有着非常重要的作用,直接影响到整个视频监控系统的性能指标.本文将对静态背景下运动目标检测技术中的帧间差分法、背景差分法进行研究,并通过实验论证其优缺点.     

Characterizing the effects of droplines on target acquisition performance on a 3-D perspective display

The present study investigated the effects of droplines on target acquisition performance on a 3-D perspective display in which participants were required to move a cursor into a target cube as quickly as possible. Participants' performance and coordination strategies were characterized using both Fitts' law and acquisition patterns of the 3 viewer-centered target display dimensions (azimuth, elevation, and range). Participants' movement trajectories were recorded and used to determine movement times for acquisitions of the entire target and of each of its display dimensions. The goodness of fit of the data to a modified Fitts function varied widely among participants, and the presence of droplines did not have observable impacts on the goodness of fit. However, droplines helped participants navigate via straighter paths and particularly benefited range dimension acquisition. A general preference for visually overlapping the target with the cursor prior to capturing the target was found. Potential applications of this research include the design of interactive 3-D perspective displays in which fast and accurate selection and manipulation of content residing at multiple ranges may be a challenge.     

The effects of motion and stereopsis on three-dimensional visualization

Previous studies have demonstrated that motion cues combined with stereoscopic viewing can enhance the perception of three-dimensional objects displayed on a two-dimensional computer screen. Using a variant of the mental rotation paradigm, subjects view pairs of object images presented on a computer terminal and judge whether the objects are the same or different. The effects of four variables on the accuracy and speed of decision performances are assessed: stereo vs. mono viewing, controlled vs. uncontrolled object motion, cube vs. sphere construction and wire frame vs. solid surface characteristic. Viewing the objects as three-dimensional images results in more accurate and faster decision performances. Furthermore, accuracy improves although response time increases when subjects control the object motion. Subjects are equally accurate comparing wire frame and solid images, although they take longer comparing wire frame images. The cube-based or sphere-based object construction has no impact on decision accuracy nor response time.     

基于ROS的六自由度机械臂运动规划

针对传统机器人在复杂环境下的安全问题以及运动规划问题,采用开源机器人操作系统ROS搭建了机器人仿真平台,并进行运动规划。在ROS平台下,利用URDF文件完成机械臂3D建模;利用Movelt配置助手(setup assistant)配置机械臂模型并且生成启动文件。在Rviz中显示三维模型;利用Movelt完成对六自由度机械臂的运动规划,以及避障轨迹规划。结果表明,通过Rqt_plot导出机械臂运动过程中六个关节的位置关系信息,可为进一步改善和研究机械臂轨迹规划提供更加直观的方法。     

Robotic motion planning and manipulation in an uncalibratedenvironment

The authors analyze planning and control problems in “robotic manipulation” in an uncalibrated environment consisting of a PUMA 560 robotic manipulator, a rotating turntable equipped with an encoder and a CCD camera based vision sensor fixed permanently on the ceiling. It is assumed that a part with a known shape but unknown orientation is placed on the turntable which is rotating with an unknown motion dynamics. Furthermore, the calibration parameters are a priori assumed to be unknown. The objective is to track the rotating part with an a priori specified relative orientation. The task considered is of importance in various problems concerning industrial automation, such as part-feeding and tool-changing     

Image-based self-position and orientation method for moving platform

The position and orientation of moving platform mainly depends on global positioning system and inertial navigation system in the field of low-altitude surveying,mapping and remote sensing and land-based mobile mapping system.However,GPS signal is unavailable in the application of deep space exploration and indoor robot control.In such circumstances,image-based methods are very important for self-position and orientation of moving platform.Therefore,this paper firstly introduces state of the art development of the image-based self-position and orientation method(ISPOM) for moving platform from the following aspects:1) A comparison among major image-based methods(i.e.,visual odometry,structure from motion,simultaneous localization and mapping) for position and orientation;2) types of moving platform;3) integration schemes of image sensor with other sensors;4) calculation methodology and quantity of image sensors.Then,the paper proposes a new scheme of ISPOM for mobile robot-depending merely on image sensors.It takes the advantages of both monocular vision and stereo vision,and estimates the relative position and orientation of moving platform with high precision and high frequency.In a word,ISPOM will gradually speed from research to application,as well as play a vital role in deep space exploration and indoor robot control.     

运动目标检测在单兵作战中的应用

考虑到单兵执行长时间侦查和狙击任务时容易出现松懈和疲劳的问题,结合成熟的双目立体视觉测量技术和ViBe算法对运动目标进行检测来进行及时的反馈和提醒。ViBe是像素级别的视频背景建模和前景检测算法,具有效果好、鲁棒性强、速度快和占用硬件资源少的特点。一方面通过ViBe算法对采集到的图像进行运动检测,得到运动目标区域信息;另一方面通过双目摄像机系统进行标定、立体匹配和三维测量,获取运动目标的位置信息。实验结果表明,该系统能够有效地检测到运动目标的区域和位置信息,达到辅助单兵作战的目的。     

目标运动要素解算方法的研究

提出了适用于水下目标运动要素估算的最小二乘估计和Kalman滤波估计模型 ,本模型被用于航空反潜作战中目标运动要素估算 ,取得了较好的效果。     

Effects of uncoupled motion on performance

OBJECTIVES: To determine whether human exposure to vehicle motion specifically affects performance on a similar, yet uncorrelated, driving task and to observe the motion/simulator sickness symptoms that were associated with the real vehicle motion and the driving task. BACKGROUND: Past research has shown uncoupled motion can affect a person's performance on a task as well as induce motion sickness. METHODS: Ten participants (age range = 19-25 years) completed an uncorrelated driving task while seated in a stationary real vehicle and a moving real vehicle. RESULTS: The results show participants took longer to complete the motion condition, t(9) = 1.96, p < .05, and were less accurate, t(9) = 3.73, p < .05. Scores for the Motion Sickness Assessment Questionnaire, t(9) = 3.37, p < .05, and the Simulator Sickness Questionnaire, t(9) = 3.30, p < .05, were significantly higher during the motion condition. CONCLUSIONS: Performance on the task was degraded and motion sickness heightened during the motion condition. APPLICATION: This research has potential implications for military-related tasks such as operating a command and control station or controlling a remote vehicle while simultaneously being a passenger in a real vehicle, as well as for civilian applications such as interacting with a moving map navigation system while driving a car.     

一种基于高性能DSP的雷达视频处理平台

基于最新大规模逻辑FPGA和高性能DSP芯片,结合图像处理理论,提出雷达视频回波信号数字化采集、压缩与网络化传输方法,并对雷达图像适用的压缩算法进行了研究。该平台为今后研究基于雷达视频目标回波信号的目标检测、特征研究和模式识别等技术提供了基础,并可广泛应用于指火控系统等领域。     

The effects of target location and target distinction on visual search in a depth display

Research of human-centered computing systems in industry should not avoid advances in visual display technology for safety, warning, and interaction. Novel 3D displays that present information in real depth offer potential benefits. Previous research has studied depth in visual search but depth was mostly not realized by real physical separation. Many areas of Human Factors could be augmented with the study and evaluation for operation of novel 3D displays. Such a study was presented to better understand the effects of real physical depth in association with depth redundantly coded with another feature (an additional mark on a target) distinguishing it from distracters and target location on visual search in a depth display. Target location was studied as the row or column in the visual field of view the target was positioned and also in terms of eccentricity outwardly from the center of the display. In general, depth was found to be of benefit when redundantly coded with another attribute for guiding attention. Targets were not found as fast when the target’s location was further from the center fixation point, and interactions between target distinction (depth, mark, or depth+mark) and target location provide implications for designers.     

航空相机稳定平台控制算法设计及其像移补偿

飞行过程中飞机姿态角速度变化会对摆扫式航空相机产生干扰,另外相机在拍摄时飞行方向上的景物与感光介质之间存在相对运动。为消除姿态角速度的干扰和前向像移,设计了一种基于F28335的机载相机两轴稳定平台系统。探讨了伺服控制系统的算法选择,介绍了硬件结构和软件流程。通过摇摆台试验证明,该两轴稳定平台动态精度高、运行可靠,满足相机拍摄时序和精度的要求。     

Influence factors of sparse microwave imaging radar system performance:approaches to waveform design and platform motion analysis

Sparse microwave imaging radar is a newly developed concept of microwave imaging system,which tries to combine the traditional radar imaging system with sparse signal processing theories,achieving the aim of reducing the complexity of microwave imaging systems and enhancing the system performance.In this paper,we introduce some basic concepts of sparse signal processing theory,and then apply it to the traditional radar imaging system to get the mathematical model of sparse microwave imaging system.We analyze the factors that determine the performance of sparse microwave imaging radar,including scene,waveform and platform.According to the radar model,we analyze how these factors influence the radar system and how to optimize them.Simulation results of the sparse microwave imaging radar system are also provided.