4WD Obstacle Avoidance Robot using Arduino Uno

Abstract

This paper describes the development of a four-wheel-drive autonomous obstacle avoidance robot designed using the Arduino Uno platform. The system utilizes an ultrasonic distance sensor mounted on a servo motor to actively scan the surrounding environment and identify obstacles in multiple directions. Based on the measured distances, the robot selects a safe path and navigates autonomously without human intervention. A micro-step motion technique is implemented to achieve slow and controlled movement without employing PWM-based speed control. A regulated power supply using a buck converter ensures stable operation of the controller and sensors. Experimental evaluation in indoor environments demonstrates reliable obstacle detection and effective navigation performance, making the system suitable for educational and research applications.

Introduction

This paper presents the design and implementation of a low-cost autonomous obstacle avoidance robot using an Arduino Uno microcontroller and ultrasonic sensing. Autonomous mobile robots are increasingly important in automation and service robotics, where real-time obstacle detection and avoidance are essential for safe navigation in unknown or dynamic environments. The project emphasizes affordability, simplicity, and reliability using commonly available electronic components.

The literature review highlights various obstacle detection technologies, including ultrasonic, infrared, and vision-based systems. Ultrasonic sensors are preferred for their low cost and ease of integration. However, fixed ultrasonic sensors have limited directional coverage. To address this, servo-mounted ultrasonic scanning mechanisms are adopted, allowing wider environmental sensing without significantly increasing system complexity.

The proposed system consists of three main subsystems:

• Sensing subsystem: HC-SR04 ultrasonic sensor mounted on an SG90 servo motor for directional scanning.

• Control subsystem: Arduino Uno microcontroller for processing sensor data and making navigation decisions.

• Actuation subsystem: L298N motor driver controlling four DC geared motors in a four-wheel-drive (4WD) configuration.

The hardware design ensures stable operation using a three-cell lithium-ion battery pack and a buck converter for regulated 5V supply. The L298N motor driver provides bidirectional motor control, while the 4WD chassis improves traction and stability for indoor navigation.

The software algorithm continuously monitors distance data from the ultrasonic sensor. The servo scans left, center, and right directions. When an obstacle is detected within a safety threshold, the robot stops and selects the direction with the greatest clearance. A micro-step movement strategy ensures slow and controlled motion without using PWM-based speed control.

In experimental testing, the robot successfully navigated indoor environments with static obstacles such as walls and furniture. The ultrasonic sensor operated effectively within a 2–300 cm range, with an average response time under 200 milliseconds. The system achieved approximately 95% obstacle avoidance accuracy under controlled conditions, though minor limitations were observed in narrow corners due to reliance on a single sensor.

The robot has applications in educational robotics, embedded systems learning, indoor service robots, surveillance platforms, and research prototypes.

Conclusion

This paper presented the design and implementation of a low-cost 4WD obstacle avoidance robot using Arduino Uno and ultrasonic sensing. The system successfully demonstrates autonomous navigation using simple hardware and an efficient control algorithm. Future enhancements may include the addition of side-mounted sensors for improved obstacle detection, wireless communication for remote monitoring, and intelligent decision-making algorithms to support complex navigation tasks.

References

[1] Arduino. Arduino Uno Board Documentation [2] HC-SR04 Ultrasonic Sensor Datasheet. [3] L298N Dual H-Bridge Motor Driver Datasheet. [4] TowerPro SG90 Servo Motor Datasheet. [5] R. Siegwart and I. R. Nourbakhsh, Introduction to Autonomous Mobile Robots, MIT Press.

Copyright

Copyright © 2026 Sanskruti Gaikwad , Anjali Lole, Pranita Chatte, Sakshi Kamble , Ankita Kamble. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.