Studies of Data-Carrier Technology Application for Assisting Environmental Information Ensuring for the Visually Impaired

对于帮助视力受损，RFID标签具有几个有用的特征。本研究的目的是通过以下方法展示这样一个为视障学生提供环境信息以帮助视障学生的系统的可行性：1)通过数据载体(地标)将信息附加到周围环境中；2)通过漫游机器人检测周围环境的变化。首先，我们考虑了校园内视障学生获取环境信息的几种情况，然后利用RFID进行了实验。也就是说，我们已经将RFID标签(包括无源和有源)连接到周围环境，并试验通过连接到巡航机器人上的读取器或通过接收器来读取它们。作为实验的结果，我们得出的结论是，通过这种方法来确保环境信息是可能的。接下来，我们考虑了如何使用RFID来应对以下情况：视障人士在意外的环境变化下面临困难。这里，最重要的问题是房间内信令标签的本地化。众所周知，即使对于活动的RFID来说，这个问题也很难解决。我们设计了以下方法来解决这个问题：1)通过旋转耦合的双天线来分析信号的方向，2)在房间里放置锚定标签，3)通过自组织映射(SOM)对RSS(接收信号强度)值进行聚类，4)移动机器人，我们重复定位过程1)-3)直到我们到达目标。

RFID tags are of several useful features for assisting visual impairment. The aim of this research is to show the feasibility of such a system that works to assist the visually impaired by providing with environmental information according to the following approach: 1) we attach information to the surroundings by data-carriers (landmarking), and 2) we detect the changes of the surroundings by checking them by cruising robots.Firstly, we have considered several situations in getting environmental information for the visually impaired students in our campus, and then we have made experiments using RFIDs to solve them. Namely, we have attached RFID tags (both passive and active) to the surroundings, and experimented to read them either by the reader attached to cruising robots or by the receiver. As the result of the experiment, we have got a conclusion that it is possible to ensure environmental information by this approach.Next, we have considered of how we can cope with the following situation by using RFIDs: a visually impaired person confronts a difficulty under unexpected change of surroundings. Here, the most important problem is the localization of a signaling tag in the room. This problem is known to be hard even for the active RFIDs. We have devised the following approach to solve this problem: 1) we analyze the direction of the signal by rotating the coupled twin antennas, 2) we deploy anchoring tags in the room, 3) we use clustering of RSS (received signal strength) values by means of the Self Organizing Map (SOM), and 4) moving the robot, we iterate the localization procedure 1)-3) until we reach the target.