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题名	结合生物声纳技术的导盲系统研究
作者	纪伟
学位类别	博士
答辩日期	2009-05-27
授予单位	中国科学院声学研究所
授予地点	声学研究所
关键词	生物声纳技术 导盲 线性调频信号 硬件实现
其他题名	Research on Blind Guidance System Using Biosonar Technique
学位专业	信号与信息处理
中文摘要	导盲系统和电子辅助行进( Electronic Travel Aid, ETA )设备可以帮助盲人和视觉障碍者更方便，更安全地行走并到达目的地，已经受到了越来越广泛的关注。它的研究具有重要的应用价值和学术意义。 本文结合生物声纳技术将生物探测的回波定位原理应用于导盲系统的研究中。所开发的一套ETA导盲设备体积小，功耗低，便于携带，使用宽带线性调频信号作为探测信号，具有较高的距离分辨率，能够探测多个物体，并将物体的信息映射到反馈给人耳的音频声上，使盲人利用听觉感知周围环境中物体的存在和物体的特性，起到辅助盲人行进的作用。 本文通过研究蝙蝠回波定位的原理，建立了超声线性调频信号的数学模型，运用解线性调频法对回波信号解调。我们首先搭建了数据采集平台，在软件仿真和实验的基础上验证了探测算法的有效性，得出结论：经信号处理后得到的音频提示音，其频率与探测物体距离成正比，其强度和音色可以反映物体的大小和材质，可以用于感知环境中物体的信息。在系统的硬件实现中，选取ARM微控制器作为系统的核心控制器，在ADS编译环境下操作DDS芯片产生40 kHz至80 kHz的线性扫频信号作为探测信号，使用超声静电换能器发射探测信号和接收反射回波。精心设计了系统各个模块的电路，实现了系统集成。此外，为了丰富导盲设备的功能，我们还附加了一个紧急情况信息求助模块，使用GPS引擎接收GPS数据流，经数据提取后，将使用者当前的时间和位置信息由GSM网络发送到指定终端设备上，接收者通过收到的信息可对使用者定位以提供及时的援助。 最后总结了本文的工作，指出了工作中一些需要改进的地方，并对下一步工作提出了一些想法和建议。
英文摘要	The blind guidance systems and Electronic Travel Aid (ETA) devices are used to enhance the mobility of the blind and visually impaired people so that they can reach their destination conveniently and safely. Their development have drawn wide spread attention. The research bears significant academic value in its theoretical contribution and also has a great practical implication. This dissertation applies the echolocation theory to the research work of ETA devices, the study develops a low-power small sized ETA blind guidance device which is easy to carry. The device uses the wideband Linear Frequency Modulated (LFM) signal as the detective signal and comes with high range resolution. It is able to detect multiple objects and maps their information onto the properties of the audio sound fed back to human ears. This allows the blind people to sense and to determine the existence as well as the characteristics of the objects in the surrounding environment through their auditory perceptions. It in turn helps the blinds to travel. This dissertation builds a mathematical model of the ultrasonic LFM signal based on the theory of bat echolocation. The model uses linear frequency demodulation method to demodulate the echoes. A data acquisition platform has been set up. The validity of the algorithm is confirmed through software simulation and experimental work. The study concludes that: i) the frequency of the audio feedback acquired through signal processing is directly proportional to the distance of the object being detected; ii) The strength and the timber of the audio signal reveal the size and the texture of the object. These data are used in conjunction to sense objects in their environment. As part of the hardware implementation of the system, the ARM microcontroller is selected as the core controller of the whole system, which operated the DDS chip to generate the LPM signal under the ADS compiling environment. The LPM signal is applied as the detective signal with frequencies spanning from 40 kHz to 80 kHz. Two ultrasonic electrostatic transducers are used to transmit the detective signals and receive the reflected echoes. Each system module is designed elaborately and the integration of the whole system is achieved. Furthermore, a help-seeking module which is intended to be used under the emergency situations is added to the device to enrich its functionalities. The module uses GPS engine to receive the GPS data streams. It extracts the data and sends the user’s current location information with a time stamp to a designated terminal device via GSM network which then enables the recipients to provide the user with timely assistance. In the final part of this dissertation, we concluded our work, indicated several points that need improvement and put forward some ideas and suggestions to the next step work.
语种	中文
公开日期	2011-05-07
页码	66
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/546]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	纪伟. 结合生物声纳技术的导盲系统研究[D]. 声学研究所. 中国科学院声学研究所. 2009.

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