Robotics Mine

Assiut Robotics — Minesweeper Autonomous Rover

📌 Executive Summary

The Assiut Robotics Minesweeper Rover is an autonomous field robotics platform engineered for humanitarian mine action and robotics competitions (Minesweeper International / Minesweeper Egypt). The rover combines real-time computer vision, electromagnetic/inductive sensing, optical proximity scanning, autonomous coverage planning, closed-loop motion control, and surface mine extraction mechanics into an integrated cross-layer cyber-physical system.

• Institution: Faculty of Engineering, Assiut University
• Team: Assiut Robotics Team
• Supervisor: Eng. Sayed Khader
• Demonstration Video: YouTube — Minesweeper Robot

📖 Master Documentation Navigation Hub

This repository contains multi-tiered engineering documentation covering software, firmware, electronics, and competition field strategy. Use the quick links below to navigate to specific subsystems:

🏛️ System Architecture

The robot utilizes a hierarchical dual-interface architecture providing robust separation of concerns between high-level computation, real-time deterministic control, and standalone field debugging:

flowchart TB
    subgraph OperatorLayer["Operator & Telemetry Station"]
        OP_STATION[Operator Laptop / Gamepad]
        WEB_CLIENT[Browser Diagnostic UI / WebSockets]
    end

    subgraph HighLevelCompute["High-Level Compute — Raspberry Pi 4 (Ubuntu Linux)"]
        ROS_CORE[ROS 2 Humble Middleware]
        SLAM_NODE[SLAM Toolbox / EKF Localization]
        PLAN_NODE[Zigzag Coverage & A* Planner]
        VISION_NODE[Camera + EasyOCR Mine Classifier]
        SER_NODE[Serial Bridge Interface Node]
    end

    subgraph WirelessBypass["Field Diagnostics Bypass — ESP8266 Module"]
        ESP_CORE[ESP8266 Local Web Server]
        ESP_JOY[WASD / Touchscreen Teleop]
        ESP_TELEM[Live Battery & Sensor Telemetry]
    end

    subgraph LowLevelControl["Deterministic Embedded Controller — Arduino Mega 2560"]
        STATE_MGR[System State Machine INIT / ARMED / RUN / FAULT]
        PID_CORE[Dual Wheel PID Controller + Feed-Forward]
        MOTION_CORE[Differential Drive Inverse Kinematics]

⚙️ Technical Specifications

Physical & Mechanical

• Locomotion: 4-Wheel Drive (4WD) with differential skid-steering
• Chassis Dimensions: Length 650 mm × Width 480 mm × Ground Clearance 85 mm
• Wheel Specifications: 220 mm diameter × 100 mm width rugged rubber tread
• Track Gauge (Wheelbase): $L = 150\text{ mm}$ (center-to-center lateral base)
• Mine Extraction: Motorized tailgate lift with active limit switch homing and 5× high-flux electromagnets

Electrical & Power Distribution

• Main Power Source: Tianneng TNE12-25 12V 25Ah Deep-Cycle Graphene Lead-Acid Battery
• Motor Driver: Cytron MDD10A Rev2.0 (Dual Channel, 10A continuous / 30A peak per channel)
• Power Rails:
  • 12V_MAIN: Motors, Cytron H-Bridge, and auxiliary power (Terminal J24, filtered with $2000,\mu\text{F}$)
  • 12V_MG: Dedicated electromagnet bus (Terminals MAG1–MAG5, filtered with $4000,\mu\text{F}$)
  • 5V_LOGIC: MCU logic, encoders, IMU, sensors (Terminal J22, filtered with $2000,\mu\text{F}$)
  • 5V_SERVO: Camera pan servo and auxiliary servos (Terminal J23/J13)
• Total Bulk Decoupling Capacitance: $> 11,000,\mu\text{F}$ distributed to suppress inductive motor inrush

Microcontroller & Sensors

• Low-Level MCU: Atmel ATmega2560 (16 MHz, 8 KB SRAM, 256 KB Flash)
• Encoder Resolution: 385 pulses per revolution (PPR) on output wheel shaft
• Inertial Measurement Unit: InvenSense MPU6050 (6-DOF Accelerometer + Gyroscope) via Soft-I2C on D31/D33
• Surface Detection: 5× Infrared optical proximity sensors (APRX1–APRX5) with hardware OR-gate aggregation
• Subsurface Detection: High-sensitivity inductive search coil (J40) for buried metallic mines

🚀 Quick Start Guide

1. Arduino Mega Firmware

1. Open Minesweeper2026/Arduino/MotorController/MotorController.ino in the Arduino IDE or VS Code / PlatformIO.

2. Select Board: Arduino Mega 2560, Processor: ATmega2560.

3. Verify feature flags in Config.h:

   #define ENABLE_WATCHDOG        1
   #define ENABLE_ODOMETRY        1
   #define ENABLE_LIFT            1
   #define ENABLE_SENSORS         1
   #define USE_SOFT_I2C_FOR_IMU   1

4. Compile and flash to the Arduino Mega via USB.

2. Standalone ESP8266 Telemetry & Debugging Dashboard

1. Open Minesweeper2026/Arduino/WiFiController/ in the Arduino IDE.
2. Connect an Arduino Uno with RESET tied to GND as a hardware bypass programmer (TX to TX, RX to RX).
3. Flash the code to the ESP8266.
4. Power the rover, connect your phone or laptop to the created Wi-Fi Access Point (Minesweeper_Rover), and browse to http://192.168.4.1 for full manual control, battery monitoring, and telemetry.

3. ROS 2 Workspace (Ubuntu Linux with ROS 2 Humble)

Clone or navigate to the workspace, install system dependencies, and build:

cd rover_ws
rosdep update
rosdep install --from-paths src --ignore-src -r -y
colcon build --symlink-install
source install/setup.bash

Launching Gazebo Simulation

ros2 launch rover_bringup simulated_robot.launch.py

Launching on the Physical Robot

ros2 launch rover_bringup real_robot.launch.py

Running Joystick Teleoperation

ros2 launch rover_controller joystick_teleop.launch.py

📡 ROS 2 Topics & Interfaces

🛠️ Field Troubleshooting Matrix

Summary of the 12 verified physical hardware and firmware issues resolved during field testing (detailed root cause analysis available in Minesweeper_Competitions_Overview.md):

📋 Pre-Flight Commissioning Checklist

Before deploying the rover onto the competition field or test arena:

1. Battery Health: Verify open-circuit voltage >= 12.6V (Do not operate below 11.8V).
2. Mechanical Fasteners: Inspect wheel hubs, motor brackets, and lift linkages for play.
3. Bench Motor Direction Check: Elevate chassis; command forward motion; verify both wheels spin forward.
4. Encoder Calibration: Rotate each wheel 1 full revolution by hand; verify ~385 counts accumulated.
5. Watchdog Fail-safe: Disconnect serial cable while motors run; verify complete motor shutdown within 1.5s.
6. Limit Switches: Manually depress top/bottom switches; confirm instantaneous lift motor deactivation.
7. Sensor Simulation: Pass metallic and surface mine samples; verify blue status LEDs illuminate and siren triggers.
8. Wire Harness Dress: Inspect Soft-I2C flying leads; ensure separation from high-current motor cables.

👥 Contributors & Team

• Assiut Robotics Team — Faculty of Engineering, Assiut University
• Academic Supervisor: Eng. Sayed Khader
• Firmware, Controls & Hardware Review: Control & Embedded Systems Engineering Sub-team

📄 License

This repository is released under the MIT License for educational, humanitarian demining research, and non-commercial competition purposes.