Indoor Magnetic Wayfinding For The Visually Impaired

描述(由申请人提供)：先进医疗电子公司(AME)建议开发一种利用现代人造结构中存在的独特磁异常模式的室内寻路设备。该系统将记录传感器在三个垂直轴上产生的磁场强度。这些磁性数据点的时间历史可以连续地与磁性异常的电子地图(或“签名”)相比较，以确定建筑物内的当前位置。第一阶段开发的原型系统在可行性实验中进行了跟踪，精度为1英尺(半径)。磁力异常使磁罗盘无法确定方向。然而，这些同样不可见的异常代表着宝贵的、独特的室内地形特征，可以通过安装在小型便携设备中的磁性传感器来测量。这样的设备将能够为低视力用户提供一种宝贵的室内低成本定向工具，类似于室外使用的全球定位系统(GPS)设备。大约有370万美国人视力残疾。在这些人中，20万人失明，其余的人视力低下。与其他方法相比，这项建议中提出的寻路概念的主要优势是，可以在不需要昂贵的建筑基础设施投资的情况下，为视障社区提供好处。这对大型政府大楼和教育校园特别有利。建议的方法为这些建筑物内的寻路提供了一个具有成本效益的解决方案。

DESCRIPTION (provided by applicant): Advanced Medical Electronics (AME) proposes the development of an indoor way-finding device utilizing the unique magnetic anomaly patterns that exist in modern, man-made structures. The proposed system will record the magnitude of magnetic field strength from sensors in three orthogonal axes. The time history of these magnetic data points can be continuously compared with an electronic map of magnetic anomalies (or, "signature") to determine current position within a building. The phase I developed prototype system tracked in feasibility experiments with an accuracy of 1 foot (radius). Magnetic anomalies render a magnetic compass useless for finding a directional bearing. However, these same invisible anomalies represent valuable, unique indoor terrain features measurable by magnetic sensors located inside a small, portable device. Such a device would be able to provide low-vision users with a valuable indoor low-cost way-finding tool analogous to a Global Positioning System (GPS) device used outdoors. About 3.7 million Americans are visually disabled. Of these, 200,000 are blind, and the rest have low vision. The key advantage of the way-finding concept presented in this proposal, over other methods, is that the benefits are made available to the visually impaired community without requiring expensive building infrastructure investments. This is of particular advantage to large government buildings and educational campuses. The proposed approach allows a cost effective solution to way-finding within these buildings.