基于三轴加速度传感器的跌倒检测技术的研究与应用-电子与通信工程专业论文.docx

I I 摘要 随着老龄化社会的到来，有助于老年人的远程医疗、远程活动监测系统已成为无线传感 器网络领域的研究热点之一。跌倒检测系统的主要目标是能够将跌倒和正常的日常活动行为 区分开来，准确无误地监测跌倒行为的发生，判断是否需要报警，尽可能降低跌倒对老年人 带来的伤害。 传统的系统解决方案主要有视频图像分析法和声频信号分析法，但它们都有一定的局限 性。而穿戴式检测装置具有体积小、方便携带、低功耗等特点，满足跌倒检测系统的需求， 通过单片机采集到三轴加速度数据，无线传输信息进行实时监测，以达到跌倒报警的目的。 本文对基于 MEMS(Micro-electro-mechanical System)惯性传感器的跌倒检测系统进行了 研究。首先采用 MMA7455 三轴加速度传感器和 CC2430 平台构成数据采集节点，三轴加速 度数据通过射频发送给传感器网关节点，由串口把数据传输至 PC 机，得到跌倒动作和日常 行为的原始数据，利用硬件补偿和卡尔曼软件滤波的方法降低了噪声产生的误差。然后在以 SVM（Signal Magnitude Vector）为特征量，竖直方向上的偏移角和速度为辅助判断的基础上 提出了一种三级跌倒检测算法。最后在 PC 机上使用 C#语言，visual studio 2010 开发环境对 跌倒检测系统进行了实现，通过试验证明了系统的准确性和可行性。 关键词: 无线传感器网络 ，三轴加速度传感器 ，跌倒检测算法 II II Abstract With aging population becoming a worldwide problem, how to realize effective and reliable elderly people-oriented remote medical treatment and activity detection system has become one the hot topics in the research field of Wireless Sensor Networks.The main goal of fall detection system is to distinguish falls and some other activities in daily life, detect falls accurately and give alarms if necessary to minimize fall injury. Traditional solutions include video image analysis method and audio signal analysis method which both has some limitations. However wearable detection device is smaller and easy to carry with, it also has low power consumption, which meet the requirements of fall detection system. The device collects striaxial accelerometer data through microcontroller unit and transmits them wirelessly for real-time monitoring in order to give accurate fall alarms. To address these problems, this paper has made some valuable researches of fall detection system based on MEMS(Micro-electro-mechanical System). In this paper, we use tri-axial accelerometer MMA7455 and platform CC2430 to constitute the data acquisition node, triaxial accelerometer data are transmitted to sensor gate node through radio frequency then to PC through serial port, the original data of unintentional fall and daily behavior are collected. This paper also reduces