Design of an Autonomous Night Patrolling Bot with IoT-Based Remote Monitoring and Multi-Sensor Intrusion Detection

Abstract

Securing residential colonies, campuses, warehouses and restricted industrial zones after dark still depends largely on human guards and fixed CCTV cameras, both of which suffer from fatigue, blind spots, poor low-light imaging and delayed reporting. This paper presents the design of a low-cost autonomous night patrolling bot that traverses a predefined route, detects obstacles, human movement and abnormal sound, and reports incidents to a remote user through an Internet of Things (IoT) platform. An Arduino Uno executes the patrol and sensing logic using an HC-SR04 ultrasonic sensor, an HC-SR501 passive infrared (PIR) sensor and a KY-038 sound sensor, while an L298N driver controls four DC gear motors. An ESP32-CAM module fitted with infrared illuminators provides night-vision snapshots and live video, and a Node MCU ESP8266 acts as the Wi-Fi gateway to a Blynk or Things Board dashboard. To reduce false alarms that affect single-sensor designs, a graded alert scheme fuses PIR and acoustic evidence and uses a stop-and-scan patrol cycle so that PIR readings are taken only when the platform is stationary. Analytical design checks indicate an obstacle-detection margin of more than 20 cm at a travel speed of about 0.34 m/s, an estimated operating time of roughly 2.4–3.3 h from a 3S Li-ion pack, and a total hardware cost of about ₹4,010. A structured validation plan with measurable performance indicators is also proposed.