Smart Path Following Robot

This project was developed within the Orange Digital Center Morocco , a space dedicated to fostering innovation, creativity, and rapid prototyping. At the FabLab, individuals and teams have access to state-of-the-art tools, including 3D printers, laser cutters, and a variety of electronic and mechanical resources. The center provides a collaborative environment where innovators, entrepreneurs, and students can transform their ideas into tangible products. By focusing on sustainable and impactful solutions .

Embark on an exciting journey into robotics with this black line follower robot! This project is more than just a machine—it’s a step toward mastering the art of intelligent navigation. Combining the precision of line-following sensors with the adaptability of obstacle detection, this robot doesn’t just follow a path—it makes decisions to find the best way forward. Whether you’re a beginner looking to dive into the world of robotics or an enthusiast aiming to challenge your skills, this project is your gateway to innovation and problem-solving. Let’s build something extraordinary!

For building the Advanced Line Follower Robot with Intelligent Path Tracking, you'll need the following components:

1. Arduino UNO – The main controller for your robot, managing all operations.
2. 4 x TCRT5000 Infrared Sensors – For detecting the line and tracking the path.
3. 2 x Li-ion Batteries – To power the motors and sensors.
4. 3 x SG90 Servo Motors – For controlling the robot's movement and steering.
5. HC-SR04 Ultrasonic Sensor – For obstacle detection and intelligent navigation.
6. Jumper Wires – For making all the necessary connections between components.
7. 2-Wheel Chassis Kit – The robot’s frame, including wheels and the motor mount.
8. Breadboard – For organizing and testing the electronic components.
9. Scotch Tape (Black) – Used to create the path (line) that the robot will follow.

These materials will allow you to build a smart robot capable of following a line and avoiding obstacles, with an intelligent path tracking system.

Before diving into the full assembly and coding, it's essential to test the motors with the L293D motor driver to ensure everything is working correctly. The L293D is a popular motor driver that allows you to control the direction and speed of DC motors, making it a perfect choice for controlling the movement of your line-following robot. In this step, we'll connect the motors to the L293D and check if they run forward and backward properly, confirming that the motor driver is functioning as expected. Once the motors are verified, you'll be ready to proceed with the next steps of the project, including integrating sensors and writing the code. Let's get the motors moving!

This code controls a two-motor robot using an L293D H-Bridge. It enables the robot to move forward, backward, and turn left or right by controlling the direction of the motors through the Arduino pins.

In this step, we will test the four infrared (IR) sensors and the two motors to evaluate the robot's ability to follow a line. To begin, use black scotch tape to draw a continuous line on a white surface. The IR sensors will detect the line, allowing the robot to follow it by adjusting the motor speeds based on the sensor inputs.

The robot uses 4 IR sensors placed strategically in front of it. This configuration is ideal for line following because it provides enough coverage to detect the line's position relative to the robot, ensuring accurate steering. Here's why four sensors are preferred over fewer or more:

1. Four sensors offer a balanced approach, providing ample data for the robot to make precise decisions about its position on the line. With two sensors on each side, the robot can determine if it's off-center and adjust accordingly. This allows for smoother turns and more responsive navigation.
2. Using fewer than four sensors (e.g., two) limits the robot's ability to accurately detect the line’s position, leading to less precise movements, especially when making sharp turns or when the line shifts slightly. A robot with two sensors would have a harder time identifying the direction in which to turn if it veers off the line.
3. More than four sensors could result in unnecessary complexity. While it may provide additional data, it also increases the chances of false readings and makes the system harder to calibrate. The added complexity is often not needed for most basic line-following applications.

Once the IR sensors are positioned correctly and the line is drawn, test the setup by observing how the robot reacts to different turns and intersections. The motors should adjust their speed based on the sensor readings, allowing the robot to stay on the line and make smooth, controlled movements.

This setup is essential for enabling the robot to follow the line autonomously, and once tested, the sensor logic will be incorporated into the full line-following algorithm.

This code controls a line-following robot using four IR sensors to detect the black line. Based on sensor readings, the robot adjusts its movement (forward, left, right, or stop) by activating the motors connected to an L293D driver.

To test the servo that's holding the ultrasonic sensor, the servo is programmed to sweep through a 180-degree range. During this motion, the ultrasonic sensor continuously measures distances to detect obstacles. If an obstacle is detected within a predefined threshold in the robot black line direction, the robot stops signaling that the path is blocked. If no obstacles are detected within the range of motion, the sensor confirms the area is clear, and the robot proceeds to navigate in that direction. This method allows the robot to dynamically scan and choose obstacle-free paths for efficient movement.

Now that we've tested the motors, servo, and IR sensors, it's time to assemble the robot and calibrate everything for optimal performance. In this step, we will focus on properly positioning the IR sensors, adjusting the ultrasonic sensor, organizing the wiring, and optimizing the turning speed to ensure smooth navigation.

1. Assembling the Robot:

Start by attaching the IR sensors to the robot's front. The distance between each sensor is critical for accurate line following. A typical setup involves placing the sensors at equal distances along the robot’s width, ensuring that they can detect both edges of the line and the center. A common distance between each IR sensor is 2 to 3 cm. This spacing allows the sensors to track the line smoothly and makes the robot responsive to slight shifts in the path.

After attaching the IR sensors, make sure they are positioned directly above the black line drawn on the floor. You want the sensors to be as close to the line as possible without touching it.

2. Calibrating the IR Sensors:

To ensure the robot can follow the line correctly, each IR sensor must be calibrated based on the distance from the black line. This means adjusting the height of each sensor so that it detects the black line without any issues. The goal is to make sure that the sensors respond consistently when they are above the line and do not get false readings when placed slightly off-center.

You may need to fine-tune the position of the sensors by shifting them slightly up or down, ensuring they are at the correct height relative to the floor.

3.Adjusting DC motors speed :

During initial tests, you might find that the robot turns too quickly when attempting to follow the line, which can prevent it from properly detecting new sensor values during the turn. This issue occurs because the robot turns at high speed, not giving enough time to read and respond to changes in sensor inputs.

By controlling the Enable pins on the L293D motor driver, I was able to reduce the speed of the motors (analogWrite(en1, 180); analogWrite(en2, 180)) when turning left or right, allowing the robot to make smoother, more precise turns. This ensures that the robot has sufficient time to process the sensor inputs during turns and navigate more effectively at crossroads.

4. Adjusting the Ultrasonic Sensor:

The ultrasonic sensor should be mounted on a servo motor with a 3d printed holder to allow it to rotate and scan the area in front of the robot. Make sure the sensor is properly secured on the servo and facing forward, able to detect obstacles within a defined range. You may need to adjust the servo angle and test the sensor’s ability to detect objects in front of the robot. This is especially useful when the robot reaches a crossroad and needs to decide which path to take.

5. Cabling and Power Supply Setup:

Carefully route all wires from the sensors, motors, and servo to the Arduino board or microcontroller. Make sure each wire is connected to the correct pins as defined in the code, and secure the connections to avoid any loose wires that might interrupt the robot’s function.

Position the battery power supply beneath the robot’s chassis, ensuring it’s firmly attached and does not interfere with the robot’s movement. The power supply should provide sufficient power for the motors, sensors, and the Arduino board.

In this step, you will test the integration of the ultrasonic sensor (HC-SR04) and the servo motor to enhance the functionality of your two-wheeled line-following robot. While the robot primarily follows a line, the ultrasonic sensor and servo motor will enable it to detect obstacles and intelligently navigate crossroads.

The servo motor will rotate the ultrasonic sensor to scan in multiple directions—left, right, and forward. The ultrasonic sensor measures distances by emitting sound waves and detecting their reflections, allowing the robot to determine the presence of obstacles. At a crossroad, this setup will help the robot check for obstacles in each direction and choose the path that is clear.

This functionality ensures that the robot not only follows the line but also makes obstacle-aware decisions when it encounters intersections, enhancing its ability to navigate complex environments. Testing this step will confirm that the robot can successfully integrate obstacle detection with its line-following logic.

This code integrates a servo motor, ultrasonic sensor, and IR line sensors to control a two-wheeled robot that follows a line, detects obstacles, and navigates crossroads by scanning paths and choosing the obstacle-free direction. It uses motor control functions to move, turn, or stop the robot based on sensor inputs and programmed logic.

Once everything is assembled and the wiring is set up, turn on the robot and conduct initial tests. Ensure the robot follows the black line smoothly, reacts to turns, and adjusts its position based on the IR sensor inputs. Additionally, check the ultrasonic sensor’s performance—ensure it rotates and detects obstacles correctly.

Test the robot’s ability to choose the best path when encountering a crossroad, using the sensor inputs and the ultrasonic sensor’s obstacle detection to make decisions.