6. Electrical Architecture

This page serves as an introduction to the electrical architecture of our Autonomous Underwater Vehicle (AUV). Throughout the year, more details and documentation will be developed. This guide outlines the basics of how our robot is connected and operates.

Battery

• Type: Lithium Polymer Batteries
• Voltage: 14.8V
• Capacity: 10Ah
• Brand: BlueRobotics
• Convenient for transport during competition season.
• Provides sufficient power for AUV's activities.
• The AUV will include two batteries in parallel configuration.

Jetson

• Onboard Computer: Nvidia Jetson AGX Orin
• Responsibilities:
  • Processes camera input.
  • Handles sensor data.
  • Executes program commands.
• Electrical Task: Powering and maintaining Jetson's stability. A section of the power board is designed for this purpose.

Thruster

• Thrusters Used: T200 from BlueRobotics
• Connection: The Electrical Speed Controller (ESC) connects thrusters to the microcontroller.
• Control: The microcontroller controls thrusters via PWM (Pulse Width Modulation) signals.

Power Board

• Function: Takes battery input and converts battery voltage to the desired voltage for components (Jetson, thrusters, DVL, etc.).
• Features:
  • It is a dual battery system.
  • Includes two kill switches: one for thrusters and one for the entire system.
  • Voltage sensing for batteries and current sensing for thrusters.
  • Includes a water detection module.
  • Utilizes resettable fuses for thrusters.

Actuator Board

• Function: Controls grabber, dropper, and torpedo mechanisms.
• Specifications: Supports 4 servos with current sensing.

Pressure Sensor

• Function: Senses water pressure.
• Data Usage: Data is utilized to detect the AUV's depth in water.

Display Board

• Function: Displays critical information about the robot:
  • Battery voltage
  • Thruster status
  • Tether status
  • Dual battery status
  • Robot status message
  • Device status
• Additional Role: Powers up the pressure sensor.

Hydrophone Board

• Function: Filters data from hydrophones.
• Operational Details:
  • Computes time differences to help localize the robot.
  • Detects water-based frequencies.
  • Picks up the desired frequency and amplifies the detected signal.
  • Transmits data to the Jetson.

IMU (Inertial Measurement Unit)

• Function: Measures and reports:
  • Specific force
  • Angular rate
  • Body's orientation

DVL (Doppler Velocity Log)

• Description: An acoustic sensor that estimates velocity relative to the sea bottom.
• Operational Mechanism:
  • Measures frequency shift from the received echo.
  • Aids AUV in determining speed and direction during movement.
• Model Used: A50 from WaterLinked (compact and lightweight compared to older, heavier alternatives).