Ultrasonic Radar: An Arduino Based Object Detection and Distance Mapping System

Abstract

This paper presents the design and development of an Ultrasonic Radar system based on the Arduino Uno microcontroller, the HC-SR04 ultrasonic distance sensor and the SG90 servo motor. Radio Detection and Ranging (RADAR) was originally developed using radio waves to determine the range, position, or speed of objects. However, conventional radar requires a relatively long acquisition time, has a short recognition range, is not target-specific because of its wide beam, and is comparatively expensive and oversensitive. A more affordable, simple and effective alternative is to use an ultrasonic sensor, which uses sound waves for ranging and detection. This paper presents a procedure in which the Ultrasonic Sensor (HC-SR04) acts as the RADAR unit. The HC-SR04 is mounted on a Servo Motor (SG90) for rotation/sweeping. These parts are interfaced with an Arduino Uno, which is programmed to detect and indicate the position of an object. Typically, the operating frequency of ultrasonic waves is around 20 kHz, but the HC-SR04 used here operates at 40 kHz with a detection range of 2 cm to 400 cm, making it well suited for short-range detection tasks.

The proposed system utilizes high-frequency ultrasonic sound waves to detect and measure the distance of objects within its operating range. The ultrasonic transmitter and receiver module is interfaced with the Arduino microcontroller, which processes the time-of-flight data to calculate the object distance in real time. A rotating servo motor provides scanning capability across an angular range of 0° to 180°, while the detected data can be visualized on a graphical interface that simulates a radar screen on a computer. This low-cost, non-invasive system has wide potential applications in robotics, obstacle-avoidance systems, automation, security and indoor environmental mapping.