Findings indicate that the integration of multi-sensor inputs with FSM-based validation provides a structured and selective approach for area violation detection.
Abstract
Restricted-area security requires detection systems that can identify human intrusion rapidly and accurately while reducing false alarms caused by non-human objects. Conventional single-sensor security systems may be limited in distinguishing humans from inanimate objects crossing a monitored boundary, particularly when the system relies only on perimeter interruption or motion detection. This study aims to design and evaluate an ESP32-based area violation detection system that integrates a Beam Sensor, Passive Infrared (PIR) sensor, and HC-SR04 ultrasonic sensor using a Finite State Machine (FSM) decision model. The Beam Sensor functions as the initial perimeter trigger, the PIR sensor verifies human presence based on body infrared radiation, and the ultrasonic sensor provides supporting distance information for spatial monitoring. Sensor readings are processed through sequential FSM states to determine whether an alarm condition should be activated. The prototype was tested in 30 trials involving human and inanimate objects at distances ranging from 1 m to 5 m. The experimental results show that the proposed system achieved an accuracy of 83.33%, precision of 85.71%, recall of 80.00%, and F1-score of approximately 82.76%. The HC-SR04 ultrasonic sensor also produced an average measurement error of 1.68% within the tested range of 50–300 cm. These findings indicate that the integration of multi-sensor inputs with FSM-based validation provides a structured and selective approach for area violation detection. Although the system is designed to address limitations commonly found in single-sensor configurations, further comparative testing against beam-only, PIR-only, and ultrasonic-only systems is required to empirically confirm its relative performance advantage.
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.
Jason Yeo Qi Wen, Siti Fatimah Sulaiman, N. Sunar· International journal of res...· 0 citations
The designed system successfully improved installation safety and reduced the risk of equipment damage and fire and was developed using an ESP32 microcontroller integrated with a PZEM-004T sensor, a DHT22 sensor, and an MQ-2 sensor.
I. M. D. P. Putra, Nardi Nardi, Dibyo Susanto et al.· Internet of Things and Artif...· 0 citations
Gas leakage can create fire, explosion, and health hazards when it is not detected promptly. This study developed a laboratory-scale gas-leak detection prototype that integrates an MQ-2 metal-oxide sensor, Arduino Uno, 16×2 I2C LCD, audible and visual warnings, a relay, and an automatically activated exhaust fan. Prototype performance was evaluated through distance-based sensor-response tests, alarm-response-time trials, and time-resolved ventilation tests. The average MQ-2 output declined from 721.0 ADC counts at 5 cm to 150.0 ADC counts at 30 cm, indicating a consistent distance-dependent response under the reported test conditions. The warning chain activated in an average of 2.0 s. After fan activation, the average ADC response decreased by 46.7% after 30 s and 79.9% after 60 s relative to the initial reading. These percentages describe changes in relative sensor output, not calibrated gas concentration, because no certified reference-gas or parts-per-million calibration was performed. The prototype demonstrates the feasibility of combining local detection, warning logic, and automatic ventilation in one low-cost platform. It is intended as an educational and supervised proof of concept and should not be treated as a substitute for a certified combustible-gas detector or explosion-protected safety system.
Raul Gonjales Barus, U. Fatmawati, Dananjaya Ariateja et al.· Jurnal Penelitian· 0 citations
To address the problems of slow response, high false alarm rate, single detection dimension, and lack of intelligent linkage in traditional fire warning systems, this paper designs and implements an intelligent fire early warning system based on a dual STM32F103C8T6 master-slave architecture and a K230 edge computing unit. The system integrates smoke, temperature-humidity, and flame sensors along with the YOLO vision model. It adopts a weighted voting-based multi-source data fusion decision mechanism. Under interference conditions such as low illumination and occlusion, the system enhances robustness through image enhancement and a temporal voting mechanism. Data is wirelessly transmitted to the OneNET cloud platform and a WeChat mini-program via the ESP8266 module using the MQTT protocol. When a fire is detected, the system can automatically execute emergency responses including power cutoff, smoke exhaust fan activation, and water pump startup. Test results show that the system operates stably, responds quickly, achieves high recognition accuracy and low false alarm rate, making it suitable for early fire warning in homes and small spaces.
Bo Ye, Cheng Yang· International Conference on...· 0 citations
Reversing radar can monitor and warn the obstacles behind the vehicle in real time, and effectively reduce the incidence of reversing accidents. It is a key vehicle safety auxiliary system to make up for the defects of traditional reversing methods and improve parking safety. In this paper, an intelligent ultrasonic reversing radar system with DE2-115 FPGA development board as the core is designed and implemented. The system hardware adopts a modular architecture. The core components include HCSR04 ultrasonic sensor, LCD1602 liquid crystal display, four-digit digital tube, LED indicator and buzzer. The modules cooperate to complete distance detection and intelligent alarm functions ; the software is based on Verilog HDL hardware description language to achieve a complete digital logic design, including ultrasonic ranging, hierarchical alarm control, digital tube dynamic scanning and LCD display driver modules ; the experimental results show that the system can measure the distance of obstacles in real time and accurately, respond quickly and run stably. It can realize three-level sound and light alarm according to the threshold, and output distance information and safety state synchronously through digital tube and LCD, which can effectively improve the safety and intelligence level of reversing operation. It can provide practical reference for the design of embedded measurement and control system based on FPGA.
Guo-Qing He, Yanfei Teng, Hanhong Tan et al.· International Conference on...· 0 citations
This paper presents the design and implementation of a proximity-based collision detection system using an HC-SR04 ultrasonic sensor and an Arduino Uno R3 microcontroller. The system provides audible feedback through a passive buzzer whose beeping frequency is dynamically adjusted according to measured distance. Three distinct operational zones are defined: continuous slow beeping for distances above 15 cm, progressively increasing beep rate in the 5–15 cm range using the Arduino map() function, and a constant tone for distances below 5 cm. The ultrasonic ranging function is implemented manually without any external library. Experimental results confirm consistent distance readings within ±1 cm over the rated 2–400 cm range, and audible zone transitions proved intuitive during user testing. The design is compact, low-cost, and directly extensible to multi-sensor or visual-feedback configurations.
