Development and Realization of an Ultrasonic Ranging Detection and Tracking Device

Abstract

There are several ways of contactless distance measurements. This research work made use of the principle of ultrasonic distance measurements and calculations as well as tracking of dynamic object by the techniques of distance comparison. When an electrical pulse of high voltage is applied to the ultrasonic transducer it vibrates across a specific spectrum of frequencies and generates a burst of sound waves. Each time any obstacle comes ahead of the ultrasonic sensor, the sound waves will reflect in the form of echo and generates an electric pulse. The time taken between sending sound waves and receiving the echo was calculated and the patterns of echo were compared with the patterns of sound waves to determine the detected signals condition. The device consists of two HC-SR04 ultrasonic sensors that sweep continuously through 1800 to detect and track object based on developed and installed codes in the Arduino Uno microcontroller and displays the range and angular position using Processing 3 Software on a computer screen display. The envisaged minimum and maximum range of object detections is 2cm and 39cm respectively using processed signal. However, the measured distance is from 5cm to 35cm and the corresponding calculated distances using waveforms from an oscilloscope were 6.8cm and 47.6cm. The discrepancies were attributable to the 0.2ms rise time of the trigger signals. The device was capable of tracking only relatively slow-moving objects and can be applicable in robotic vision, automatic guided vehicles, security surveillance, automobile anti-collision system and precision contactless measurements.