Predator Bot V1

Heat-Seeking Predator Bot

This project involved designing and building an autonomous robot capable of tracking and following a person based on their heat signature. The bot integrates various sensors, actuators, and a custom PCB for hardware interfacing, exemplifying a multidisciplinary approach to mechatronics.

Table of Contents

1. Introduction
2. Specifications
3. Design Development
   • Hardware Design
   • Software Design
4. Results
5. Lessons Learned
6. References

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Introduction

The Heat-Seeking Predator Bot was designed to:

• Detect and follow a person using a thermal camera and IR distance sensor.
• Maintain a proximity range using motor control.
• Demonstrate multitasking capabilities for real-time operation.

The bot was built using an ESP32 FireBeetle microcontroller, with custom PCB and housing, leveraging various sensors and actuators to create a functional prototype.

Specifications

The bot's key specifications are:

• Thermal Camera: Adafruit MLX90640 (20–40°C, ±5°C accuracy).
• IR Distance Sensor: Sharp GP2Y0A21YK0F (2–36 inches, ±0.5-inch accuracy).
• Inertial Measurement Unit (IMU): Adafruit BNO055 for motion control.
• Motors: N20 DC motors with magnetic encoders and DRV8871 motor drivers.

Pass/Fail Criteria

• Tracks heat signatures.
• Maintains a 2–36-inch range from objects.
• Streams thermal heatmaps to a web interface.

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Design Development

Hardware Design

The custom PCB was created using KiCAD and included:

• Screw terminals for component connectivity.
• Proper trace sizing for power and heat dissipation.
• Compact layout to minimize weight and improve balance.

The bot’s housing was designed to securely hold all components while minimizing weight-induced friction.

Software Design

The software was modular, focusing on individual sensor functionality before integration:

• Thermal Camera: Detected heat signatures and converted data to ASCII for debugging.
• IR Distance Sensor: Measured distance using voltage-to-distance calibration.
• IMU: Provided acceleration data to refine motor control.
• Motor Control: Implemented PID for speed adjustments.

Due to time constraints, full system integration was not achieved.

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Results

While the bot's PCB design required significant revisions, the sensors functioned as expected when tested individually. Challenges included:

• Inadequate motor speed and torque.
• Integration of components due to missing PCB features.

Despite these setbacks, the project provided valuable hands-on experience.

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Lessons Learned

Key takeaways include:

1. Early Planning: A thorough design phase and literature review are essential.
2. PCB Design: Focus on component connectivity, power handling, and adequate debugging options.
3. Prototyping: Iterative testing is vital for identifying and resolving design flaws.

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References

• Adafruit MLX90640 GitHub Repository
• Adafruit BNO055 GitHub Repository
• Predator Bot Repository

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Acknowledgments

This project was completed as part of ME 507 at Cal Poly San Luis Obispo. Special thanks to the Mechatronics Department for providing resources and support.

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