Target Tracking

Overview

Target tracking is an important application of drone intelligence. In this project, you will learn how to use OpenCV library for real-time color target tracking.

What You’ll Learn

• OpenCV library usage
• Color space conversion
• Contour detection
• Target tracking algorithms

Materials Needed

Step 1: Understand OpenCV

OpenCV is an open-source computer vision library that provides rich image processing and computer vision algorithms.

Step 2: Open the Project

Extract opencv_tracking.zip and open with VS Code.

Step 3: Implement Color Recognition

Open color_tracking.c and implement color recognition:

void color_tracking(uint8_t* frame, int width, int height, int* target_x, int* target_y) {
    // 1. Convert RGB image to HSV space
    cvt_color_rgb2hsv(frame, width, height);
    
    // 2. Apply color threshold filtering (red)
    uint8_t mask[width * height];
    hsv_threshold(frame, width, height, mask, 0, 10, 100, 255, 100, 255);
    
    // 3. Find contours and calculate target center
    find_contours(mask, width, height);
    if (has_contours()) {
        *target_x = get_largest_contour_center_x();
        *target_y = get_largest_contour_center_y();
    } else {
        *target_x = -1;
        *target_y = -1;
    }
}

Step 4: Add Tracking Control

void track_red_ball() {
    int target_x, target_y;
    detect_red_object(frame_buffer, WIDTH, HEIGHT, &target_x, &target_y);
    
    if (target_x != -1) {
        // Calculate error from image center
        int error_x = target_x - WIDTH / 2;
        int error_y = target_y - HEIGHT / 2;
        
        // Convert to velocity commands
        float vx = 0;
        float vy = -error_x * 0.001; // Yaw control
        float vz = -error_y * 0.001; // Altitude control
        
        // Move forward if target is centered
        if (abs(error_x) < 50) {
            vx = 0.3; // Forward speed
        }
        
        commanderSetVelocitySetpoint(vx, vy, vz, 0);
    }
}

Step 5: Compile, Flash and Test

1. Compile and flash the code
2. Place the red ball in front of the drone
3. Power on and observe if the drone follows the ball

Troubleshooting

Cannot recognize red ball

• Adjust color threshold
• Improve lighting conditions

Tracking is unstable

• Add smoothing filter
• Optimize control parameters

Achievement

Congratulations! You have implemented target tracking functionality, which is an important application of drone intelligence!

Next Steps

In the next project, you will learn how to deploy TinyYOLOv3 model on ESP32-S3 for object detection.

Continue to Project 07: AI Recognition →