An IoT-Based 360° Ultrasonic Obstacle Detection System for Real-Time Occupational Safety Monitoring

Abstract

Occupational safety remains a significant challenge in industrial and agricultural environments due to limited visibility and obstacle-related accidents. This study presents the development of an IoT-based 360° ultrasonic obstacle detection system for real-time hazard monitoring. The proposed system integrates an ESP32 microcontroller, an HC-SR04 ultrasonic sensor mounted on a 28BYJ-48 stepper motor, and the Blynk IoT platform to perform continuous 360° environmental scanning while enabling remote monitoring. A multi-level alert mechanism consisting of green, yellow, and red LEDs, together with an audible buzzer, was implemented to notify users based on predefined obstacle distance thresholds. The prototype was evaluated under Safe, Warning, and Danger operating conditions to assess its obstacle detection performance, response time, and system reliability. Experimental results demonstrated that the system successfully performed continuous obstacle detection, correctly activated the corresponding notification mechanisms, and maintained synchronized real-time monitoring through the Blynk dashboard and radar visualization interface. The system also achieved a response time of less than 500 ms, enabling timely hazard notification. Overall, the proposed system offers a low-cost, reliable, and practical solution for improving situational awareness and enhancing occupational safety in construction, warehouse, and agricultural environments.