Testing of the device of the help to visually impaired people for positioning in space

The article is devoted to testing the device to help visually impaired people to detect obstacles such as “step up” and “step down”.The article discusses the block diagram of the device, its element base, design and algorithm, as well as the results of testing in the laboratory and on the street with heavy traffic.As sources of information on the obstacles used 2 of the ultrasonic sensor like HCSR-04 with working distance up to 4 m. Processing of sensor signals was performed using a hardware platform Arduino UNO R3. Signals about the presence of obstacles, their type and distance to them were displayed on 2 buzzers. Power was supplied from one element 9V. As a prototype of the device, a cane was used, all elements of which were made on a 3D printer of the Picaso type according to a specially developed program. The weight of the cane was 0.88 kg with the battery.The algorithm assumes the initial survey of the obstacle sensor of the “step up” type, comparison of the received signal with the software-defined threshold and in case of its exceeding the formation of an audio signal on one of the buzzers with an increase in the height of the sound as it approaches the obstacle. After bypassing or overcoming an obstacle of this type, the program proceeds to the survey of the obstacle sensor of the “step down” type, comparing the received signal with the software-defined threshold, and in the case of finding a signal in the zone below the threshold, the formation of an audio signal on the second of the buzzers with an increase in the sound height as it approaches the obstacle. The program runs in a loop.Testing of this device confirmed the efficiency of the proposed solutions, but at the same time revealed a number of disadvantages of the device:- large size and weight, making its use uncomfortable and noticeable to others;- good detection the obstacle of the “step up” only at a distance of 0.6 m and closer, and a large number of false positives for obstacles of type “step-down”, which is caused by rotation of the device around the axis of the cane during the movement and the associated turn a decrease in signal of the object sensor of the type “step-down” below the threshold level;- difficult detection of the sound signal in background noise on a street with heavy traffic.The following measures were proposed to address the identified deficiencies:- transition to another element base and construction of the cane, having smaller dimensions and weight;- changing the block diagram and algorithm of the device;- addition of a sound signal by the vibration signal.All of these changes are currently under development.