基于超声波特征信号处理的导盲仪研究

Research of the Guide Based on the Process of the Ultrasonic Characteristic Signal

导盲仪系统由超声波收发电路、特征信号处理电路、电源电路、音频播放电路组成。由超声波发生器发射超声波信号,当超声波接收器接收到回波信号之后,处理器会对回波信号进行特征提取和处理。滤除了环境带来的高频率噪声,使用信号重构算法保留原始信号的大部分特征又适当地放大,以便系统在测量前方障碍物距离的同时,能根据障碍物的不同外型进行分辨。该系统的最大探测距离为8 m,并且能分辨目标物的细微差别,精度高、稳定性好,可以满足盲人导航的基本要求。

The sonar system consists of four parts： the sonar head module,DSP control module,audio output module and power supply module. The ultrasonic generator sends out the ultrasonic waves. When the sonar receiver caught the echo,CPU will extract the features of the echo and process the features,which can not only filter the high frequency noises caused by the surrounding envrionment,but can also uses the algorithm of sigal reconstruction to retain most of the features of the original signal and properly amplified them. So that when the system measures the distance between itself and the obstacle,it can also identify the obstacle according to its shape. The maximum detection distance of the system is 8 meters,and it can distinguish the nuances of objects. It has the high accuracy and good stability,which can meet the basic requirements for blind navigation.