This project builds a robot that tracks a yellow ball using a camera. Let's delve into its components, functionality, and step-by-step creation process.
Hardware:
- Computation and Processing:
- Jetson Nano
- MicroSD card (at least 16GB, recommended 32GB or higher for extended recording)
- Power supply for Jetson Nano (refer to official specifications for voltage and amperage requirements)
- Microcontroller:
- Arduino Uno or compatible board (e.g., Nano, Mega)
- USB cable for programming the Arduino
- Motor Driver:
- L298N motor driver module
- Motors:
- Two DC motors (voltage and RPM dependant on your robot's design and desired speed)
- Camera:
- USB camera or CSI camera module compatible with Jetson Nano
- Sensors:
- Ultrasonic sensor (e.g., HC-SR04)
- Power Supply:
- New: A portable power bank (with sufficient capacity) to provide power in the field for the Jetson Nano, Arduino, and motors (consider voltage and current requirements of each component)
- Additional Components:
- Jumper wires for connecting components
- Breadboard (optional, for prototyping)
- Chassis or frame to build the robot
- Wheels appropriate for the robot's size and weight
- Screws, nuts, and mounting hardware (depending on your chassis design)
- New: Camera mount (depending on the camera chosen)
- New: Zip ties or fasteners for securing wires
Software:
- Jetson Nano Operating System (e.g., NVIDIA JetPack)
- Arduino IDE (Integrated Development Environment) for programming the Arduino
- OpenCV library (for computer vision on Jetson Nano)
Functionality:
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Video Capture and Processing:
- The Jetson Nano captures video using the camera.
- OpenCV library processes frames to detect the yellow ball.
- Ball's position and size are identified.
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Motor Control:
- Based on the ball's position, the Jetson sends commands to the Arduino.
- Arduino adjusts motor speeds to ensure the robot follows the ball.
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Safety Stop:
- The ultrasonic sensor continuously measures the distance to the ball.
- If the distance falls below a safe threshold (e.g., 10 cm), the Arduino stops the motors to prevent a collision.
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Real-Time Visualization:
- The processed video displays the detected ball, providing visual feedback.
Detailed Steps:
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Setup and Configuration:
- Connect the camera to the Jetson Nano.
- Connect motors, motor driver, and ultrasonic sensor to the Arduino.
- Establish serial communication between Jetson Nano and Arduino.
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Jetson Nano Code:
- Initialize the camera and video capture.
- Use OpenCV to detect the yellow ball in each video frame.
- Calculate the error based on the ball's position relative to the center of the frame.
- Send motor control commands to the Arduino based on the error.
- Display the video with the detected ball highlighted.
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Arduino Code:
- Receive motor control commands from the Jetson Nano via serial communication.
- Control motor speeds using PWM signals.
- Continuously read the distance from the ultrasonic sensor.
- Stop the motors if the distance to the ball is less than the predefined threshold.
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Testing and Calibration:
- Calibrate the camera and ultrasonic sensor for accurate detection and distance measurement.
- Test the robot's responsiveness to the ball's movement.
- Adjust the PID controller parameters for smooth and accurate tracking.
Applications:
- Education: Learn robotics, computer vision, and sensor integration.
- Entertainment: Interactive toy that follows a ball.
- Prototyping: Base platform for developing more advanced robots.
Challenges and Considerations:
- Lighting Conditions: Ball detection may vary with lighting. Proper setup is crucial.
- Power Management: A stable power supply ensures consistent performance.
- Real-Time Processing: Efficient video processing is needed for real-time responsiveness.
This project offers hands-on experience with integrating various technologies, creating a practical and engaging application of these concepts.