基于物联网的自动报警智能拐杖系统的设计

随着社会事件的发生,老人安全出行再次引发人们的重点关注。一种基于物联网能实现自动报警的智能拐杖能够保障老人安全出行,拐杖系统包括数据采集与数据处理的拐杖终端。该系统利用ADXL345三轴加速度传感器测量倾角精度高,SIM908模块集GPS单元与GSM 单元于一体的特点,可准确获得老人行走状态并进行判断、处理。实验结果证明,该系统可实现定位、摔倒判断、自动报警、通信等功能,克服了目前国内相关产品只能手动报警的缺陷,可为老人安全出行提供保障。     

可穿戴的实时检测走姿矫正仪设计

在走姿矫正导航精度优化问题的研究中,针对当前姿态解算技术的精度不足,设计了一款在Linux环境下嵌入式走姿矫正设计方案,基于先验的位置磁矩迭代修正方程系数的方法,建立迭代误差指标函数及迭代公式,并进行了数值仿真实验。为实现姿态解算中姿态角实时检测,提出将传感器采集到的加速度、角速度以及磁场强度数据进行融合,利用三轴加速度传感器和磁力计的向量偏差来对姿态解算过程中积分累计误差进行修正。最后传感器将数据结果分别通过ZigBee和蓝牙协议将其传输到电脑端或手机APP客户端显示,以达到走姿检测和矫正的目的。实测结果表明,这种方案使得走姿矫正的精度准确度更高,实时检测性能更强。     

基于惯性传感的人员行进动作识别方法

人员行进动作的识别对于行人航位推算(PDR)的计算精度有至关重要的影响。将连续的行进过程依据零速率修正点(ZUPT)划分为单步动作后,准确的动作识别是PDR系统的难题之一。将惯性测量单元IMU固连在胫骨中间外侧位置,采集了大量人员行进过程胫骨运动的加速度和角速度,建立了用于行进动作识别的惯性传感数据库。通过对人员的平地行走、上楼梯和下楼梯的惯性传感数据的分析,建议了一种结合运动特性寻找行进过程中零速率修正ZUPT点的方法。在完成单步步态划分的基础上,提出了一种基于支持向量机(SVM)理论,并采用惯性传感数据作为特征的SVM行进动作分类器。经大量人员行进实验验证,所建议的动作识别方法对于区分行走、上楼梯和行走、下楼梯,精度分别达到96%和85%。     

Gait analysis of people walking on tactile ground surface indicators.

Tactile ground surface indicators installed on sidewalks help visually impaired people walk safely. The visually impaired distinguish the indicators by stepping into its convexities and following them. However, these indicators sometimes cause the nonvisually impaired to stumble. This study examines the effects of these indicators by comparing the kinematic and kinetic variables of walking on paths with and without indicators. The results suggest that walking on the indicators causes extra movements of the lower extremities such as increased minimum toe heights during the midswing phase, increased peak hip flex moments, and increased peak hip heights. This study also suggests that a functional leg length discrepancy while walking on the indicators is one of the reasons for the extra movements of the lower extremities. Therefore, we designed a new recessed tactile surface to offset the differences of surface depth while walking on the path containing indicators, and found that the newly designed recessed tactile surface was effective in reducing the extra movements while walking on the path in which indicators were installed. These indicators may help both the visually impaired and elderly people with normal vision to walk safely.     

Evaluating the Effect of Various Walking Conditions on KINECT-based Gait Recognition

Human gait is one of the unobtrusive behavioral biometrics that has been extensively studied for various commercial and government applications. Biometric security, medical rehabilitation, virtual reality, and autonomous driving cars are some of the fields of study that rely on accurate gait recognition. While majority of studies have been focused on achieving very high recognition performance on a specific dataset, different issues arise in the real-world applications of this technology. This research is one of the first to evaluate the effects of changing walking speeds and directions on gait recognition rates under various walking conditions. Dataset was collected using the KINECT sensor. To draw an overall conclusion about the effects of walking speed and direction to the sensor, we define distance features and angle features. Furthermore, we propose two feature fusion methods for person recognition. Results of the study provide insights into how walking speeds and walking directions to the KINECT sensor influence the accuracy of gait recognition.     

Sonification of range information for 3-D space perception

We present a device that allows three-dimensional (3-D) space perception by sonification of range information obtained via a point laser range sensor. The laser range sensor is worn by a blindfolded user, who scans space by pointing the laser beam in different directions. The resulting stream of range measurements is then converted to an auditory signal whose frequency or amplitude varies with the range. Our device differs from existing navigation aids for the visually impaired. Such devices use sonar ranging whose primary purpose is to detect obstacles for navigation, a task to which sonar is well suited due to its wide beam width. In contrast, the purpose of our device is to allow users to perceive the details of 3-D space that surrounds them, a task to which sonar is ill suited, due to artifacts generated by multiple reflections and due to its limited range. Preliminary trials demonstrate that the user is able to easily and accurately detect corners and depth discontinuities and to perceive the size of the surrounding space.     

航空用多传感器组合导航信息融合的研究

在已有的SINS/GPS组合导航系统的基础上,将联邦kalman滤波算法与组合高度三阶回路算法动态结合,并利用改进型自适应滤波算法对系统进行实时系统噪声和量测噪声水平估计和修正,实现了SINS/GPS/高度计/磁罗盘多传感器组合导航系统有效融合。所设计系统综合利用了各传感器的优点,克服了各传感器的缺点,并能实时正确地测得载体的三维速度、位置和姿态信息,尤其是高度通道上的速度和位置信息,使多传感器组合导航系统能长时间、有效、稳定地进行飞行导航。经半实物仿真实验表明,所设计的组合导航系统具有较好的稳定性和较高的精度。     

室内微型组合导航计算机设计

通过对室内导航技术的分析,结合嵌入式控制技术和和微机电系统(micro electro mechanical systems,MEMS)技术,提出了基于MEMS惯性/视觉的室内微型组合导航计算机设计方案。该方案以室内导航的性能需求为基础,设计了以MEMS惯性传感器和摄像头为主要传感器电路,并融合各模块数据完成了计算机系统设计。测试结果表明该系统能够正确采集前方障碍物的距离信息和运动信息,体积小,可靠性高,满足室内导航的要求。     

新型绝对式磁栅位移传感器的设计

为吸取磁栅位移传感器的优点并避免精度和分辨率较低的问题,设计了一种新型的磁栅位移传感器,磁头由线性霍尔元件阵列组成,磁栅由永磁体阵列构成。为提高原始电压信号的质量,采用三相六元件的信号发生方案,通过差分处理滤除了由于装配偏差和零点漂移带来的信号误差,并对磁栅信号发生装置结构进行了ANSYS有限元电磁场分析,依据磁场分析的结果选择磁头安装间隙。在磁栅绝对位移实现方面,采用两排磁钢的方法,一排编码,记录磁头所在的周期;一排用来记录每个正弦周期的相对位移。相对位移选择了基于查表方式的信号处理算法,降低了处理芯片的运算量,并通过对高性能的16位嵌入式单片机dsPIC33FJ64MC706的开发实现了此算法。简化了信号处理硬件的外围电路,满足了磁栅小型化的设计要求,而且实现了磁栅高速的运算能力和实时的信号处理功能,提高了磁栅的分辨率和工作可靠性。     

Position estimator for underground mine equipment

A 2-D perception system that exploits the accuracy and resolution of a laser range sensor to determine the position and orientation of a mobile robot in a mine environment is described. The perception system detects features from range sensor data and matches the features to a map of the mine to compute the sensor position. The features used are line segments and corners, which represent the typical geometry of the mine walls and intersections found in room-and-pillar-type mining. The position estimate is refined by minimizing the error between the map and sensed features. This position information can be used for autonomous navigation when a map of the mine is available or to survey the mine in order to build such a map. The technique is applied to robot navigation in a mine mockup. A refinement of this system could guide machines to yield productive, safe mining operations     

Design and implementation of haptic virtual environments for the training of the visually impaired

This paper presents a haptic virtual reality (VR) tool developed for the training of the visually impaired. The proposed approach focuses on the development of a highly interactive and extensible haptic VR training system (the ENORASI VR training system) that allows visually impaired, to study and interact with various virtual objects in specially designed virtual environments, while allowing designers to produce and customize these configurations. Based on the system prototype and the use of the CyberGrasp haptic device, a number of custom applications have been developed. An efficient collision detection algorithm is also introduced, by extending the proximity query package (PQP) algorithm to handle five points of contact (a case studied with the use of CyberGrasp). Two test categories were identified and corresponding tests were developed for each category. The training scenarios include: object recognition and manipulation and cane simulation, used for performing realistic navigation tasks. Twenty-six blind persons conducted the tests and the evaluation results have shown the degree of acceptance of the technology and the feasibility of the proposed approach.     

Control of biped walking robot for human living environment

This paper introduces biped robot adaptation to human living environment from viewpoints of battery operation time extension and environmental recognition. These issues are important when robots actually work at home. First, in order to extend battery operation time, we propose energy-saving bipedal locomotion gait. The problem is formulated as an optimal control problem, which is conventionally hard to solve when a target system is complicated. In this paper, partial derivatives appeared in optimal control problem are implicitly represented by using automatic differentiation technique. This approach enables complicated optimal control problem solvable. In combination with receding horizon control, its computation cost is also reduced. Second, we introduce the biped walk tracking based on the camera image mounted on the walking robot, and the visual servoing by the posture change for the purpose of the target image tracking in the camera frame. We propose a new control law to track the rotated target object using the characteristic of the walking, which considered the interference between translational motion and rotational motion. The decoupling is realized by simulations and experiments. As a result, the walking robot tracked the translated and rotated target object without a practical issue. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

智能车路径信息图象采集控制系统的设计

随着高科技时代的到来,智能车的发展与应用也成为关注的焦点之一。目前,国内外智能车系统中的路径信息采集控制系统通常利用磁导航传感器来获取路径信息,但通常会在采集过程中出现路径位置阶跃现象从而无法确切计算实际行驶路程。本文设计的智能车路径信息采集控制系统在路径信息分析过程中采用了阈值分割的优化算法, 较好的解决了位置信息阶跃问题, 实现了普通摄像头的连续路径识别功能,使智能车的应用成为可能。通过大量实验测试,结果表明该智能车系统能够快速平稳地在赛道上跟踪黑色引导线行驶,且系统的稳定性和抗干扰能力较强。     

智能仿生人工腿步速测量系统硬件研究与设计

CIP-I Leg是国内首个智能仿生人工腿原型机。本文首先介绍了CIP-I Leg的基本结构，给出了实物照片和三维CAD视图，然后重点介绍了该人工腿步速测量系统的设计方案，包括步速调整原理、控制系统结构、针阀开度值的设置方法、以及步速测量系统硬件和软件设计等。文中，我们提出了一种新的步速测量方法，即通过测量人工腿一个完整的步行周期，用步行周期的长短来反映步行速度的快慢。在硬件电路设计中，我们采用了美国A1legro公司的A3144EUA开关型霍尔传感器和TI公司的MSP430F149微处理器。微处理器用米处理霍尔传感器的信号并计算出步行周期值。实验结果表明，所设计的步速测量系统精度高，实时性好，功耗低，能非常可靠地检测出CIP-I Leg的步行速度。     

基于磁力计在线校准的行人导航算法

航向角误差是行人导航中的主要误差之一,常见解决方案是将MIMU与磁力计组合使用,但磁力计误差较大,因此使用前需要进行校准。针对这一问题,本文提出了一种基于磁力计在线校准的行人导航算法,在行走前通过空间旋转的方式进行椭球拟合完成初步校准,之后在行进过程中使用UKF对时变误差进行实时估计并进行校准,以校准后的磁力计输出对行人航向进行修正。数据显示：基于磁力计在线校准的行人导航算法,与磁力计未校准和仅进行初始校准磁力计的行人导航算法相比,闭环误差分别下降了6.17%和2.8%。结果表明：本文提出的算法有效地校准了磁力计,并抑制了行人导航中的航向角发散,提升了导航精度。     

复合扰动下双足机器人位姿修正解耦控制研究

双足机器人在驱动步行中受到活动部件的复合扰动作用容易产生耦合误差,导致解耦控制的稳定性不好,为了提高双足机器人驱动步行中的解耦控制的稳定性,提出一种基于变步长动态平衡反馈调节的双足机器人驱动步行位姿修正解耦控制方法。采用分布式传感器阻力力学采集方法进行双足机器人的姿态参量测量和动态融合处理,构建双足机器人驱动步行位姿修正解耦控制的约束参量模型和控制目标函数,采用Kalman滤波方法进行双足机器人驱动步行的地面环境适应校正和误差修正,采用变步长动态平衡反馈调节方法确定精准的驱动步行姿态参量,实现双足机器人准确的姿态定位和参量解算。仿真结果表明,采用该方法进行双足机器人驱动步行姿态定位控制的准确度较高,环境适应性较好,实现零误差驱动步行,提高了双足机器人的控制品质。     

基于MEMS/GPS/地磁组合的弹体姿态解算

MEMS惯性器件由于具有自主性、连续性和隐蔽性等优点被广泛运用于载体的姿态解算中,但由于MEMS惯性器件的制作精度和误差积累等问题使得解算出的姿态信息并不准确.同时由于地磁传感器可以实现高精度的姿态测量,但不能独立解算出姿态信息.因此为了提高惯导姿态解算的精度,所以采用GPS、地磁辅助惯导进行姿态解算.设计的方案是在传统惯导姿态解算误差状态方程的基础上,将地磁和GPS解算的滚转、偏航和俯仰角与惯导解算出来的相应角的差值添加到传统惯导姿态解算误差状态方程中,以速度误差和滚转、偏航和俯仰角误差为量测值,估计出组合系统的姿态误差,并与惯导解算出的姿态误差进行对比,从而验证所提出的方法的可行性.     

有源交变磁场导向定位方法及实验研究

以往传统的随钻测量设备无法满足复杂结构井钻井技术高可靠,高精度的需求.为了精确钻进井眼轨迹,提出了1种基于有源交变磁场导向定位的钻井测量技术.通过研究旋转正交磁偶极子在空间的传播特性,利用低频交变磁场作为信号源,经目标靶区磁场信号采集与处理,结合常规随钻测量技术,计算出钻头与目标靶点间的相对方位和距离偏差,进而为钻进工...     

基于TMR传感器阵列与数值积分的电流测量技术研究

为满足智能电网对先进传感技术和复杂电磁环境下高精度电流测量的需求,提出一种基于TMR传感器阵列和Newton-Cotes数值求积算法的电流测量方法。通过建立复杂干扰磁场环境的仿真模型,验证了不同状况下求积算法的准确性;设计了电流传感器的系统结构和硬件电路;制作了测量装置样机,搭建了实验平台,并进行了性能测试。结果表明,文中提出的方案具有较高的测量精度和抗外磁场干扰能力,在无聚磁环的情况下,0～16 A电流测量范围内最大相对误差分别为直流0.31%和工频交流1.00%,在电流导线位置和传感器姿态发生变化时仍能保持较高精度。     

Underwater map-matching aided inertial navigation system based on multi-geophysical information

In order to achieve long-term covert precise navigation for an underwater vehicle, the shortcomings of various underwater navigation methods used are analyzed. Given the low navigation precision of underwater map-matching aided inertial navigation based on single-geophysical information, a model of an underwater map-matching aided inertial navigation system based on multi-geophysical information (gravity, topography and geomagnetism) is put forward, and the key technologies of map-matching based on multi-geophysical information are analyzed. Iterative closest contour point (ICCP) map-matching algorithm and data fusion based on Dempster-Shafer (D-S) evidence theory are applied to navigation simulation. Simulation results show that accumulation of errors with increasing of time and distance are restrained and fusion of multi-map-matching is superior to any single-map-matching, which can effectively determine the best match of underwater vehicle position and improve the accuracy of underwater vehicle navigation.