Comparison of Ultrasonic Rangefinders Sensors

The task of helping visually impaired people with the help of technical means has been relevant for more than half a century. A large number of works have been written on this topic, and a number of devices have been developed. However, they all have certain disadvantages and, as the visually impaired themselves note, a rather high price. This article is devoted to the comparison of inexpensive ultrasonic rangefinder sensors for solving the problem of object detection. They will be used in the development of assistant devices for the visually impaired. The ultrasonic sensor uses sound waves to determine location, is inexpensive, and its readings are independent of lighting conditions. Since devices of this type must have increased reliability, the beginning of the article is devoted to the measurement and verification of such sensors. These measurements showed that after 3.5 meters the readings degrade and become irrelevant. To study this problem, reflection from sensors from different manufacturers operating at a center frequency of 40 kHz and at different distances to the object was assessed. The results allow us to conclude that, most likely, the threshold value for these sensors was not optimally selected. In addition, the signals levels received by the sensors were assessed and the best option for an ultrasonic assistant device for the visually impaired was selected.