The Mark 2 electronics is the next generation electronics running Talos. These electronics were primarily developed throughout the 2022-23 academic year, taking lessons learned from Tempest’s Mark 1 electronic system to make a more reliable and polished electronics system. The electronics system underwent the following changes:

• Distributed architecture with each circuit board containing an independent microcontroller communicating over CAN Bus
• Switched the physical layout of the electronics to increase circuit board density
• Increased telemetry available from the electronics system to allow for complete system diagnostics over the network

Read more about the team’s electrical systems on the Navionics Team Page

Diagram of Mark 2 Architecture:

Talos underwent many improvements to the mechanical systems throughout the vehicle redesign. Some of these include:

• Pocketed lids to reduce weight, overall 2.7 kg lighter than Tempest
• Improved thruster cable management to reduce drag
• Electronics cages mounted on drawer slides, enabling consistent IMU placement
• Higher rigidity with new structure verified by FEA
• Thruster guards to protect against impacts with walls
• Modular task mechanism mounting
• New task mechanisms, with torpedoes and markers being integrated together
• Smart battery housings
• Adjustable center of mass position by indexing battery rails
• Reduced width, allowing it to fit through a door
• Ergonomic handles for easier transportation
• Anodized for added protection

Read more about these improvements on the Mechanical Team Page

Talos is uses the same Riptide Software stack of all of our previous AUVs. This year a focus was placed on improving the testability of our software systems, with several new systems created for this purpose:

• New editor developed for robot task code to reduce common errors faced during development
• Automated tests written for robot task code to minimize crashes during competition runs
• Improved visualization tools to view and operate the vehicle during pool tests
• Tools to allow vehicle operation without needing command line interface

Read more about the team’s software systems on the Software Team Page

The Mk1 electrical system uses a Backplane/Card design to isolate each function into 4 distinct PCB systems: Power, Electronics Speed Controller (ESC), Actuator, and Coprocessor (Copro). These custom-made cards each serve an integral function for the electronics system of Tempest.

Power Board

The power board is responsible for distributing and regulating power from our MaxAmp Lithium-ion batteries to the rest of the robot. It uses a diode/or controller to balance the batteries. Balancing is necessary in order to avoid back-feeding the batteries, which can not only damage them but also create unsafe conditions.

ESC Board

The ESC board contains one electronic speed controller for each thruster (8 in total). Taking commands from our software controller, it sends the power necessary for Tempest to move to a given location or achieve a certain orientation.

Actuator System

The actuator system is responsible for actuating the various task mechanisms required for competition: claw, torpedo, and marker droppers. The actuator board is a stacked design including a dedicated control board and a custom-designed microcontroller Hardware Attached on Top (HAT). This design was selected due to space constraints within the electronics cage.

Copro Board

The copro board is the primary interface between the main computer and the Tempest’s electronics system by running firmware. It exposes a Micro-ROS node which translates topic messages into electrical signals. Additionally it reports back robot states including battery voltage and internal temperature.

Backplane Board

The backplane board is the primary interconnect for the four individual electrical systems, linking important signals between the various boards.

Our robot uses a variety of sensors to navigate its surroundings. We use an Extended Kalman Filter (EKF) to fuse sensor data together and produce an estimate of Tempest’s current pose.

• Doppler Velocity Logger (DVL) uses the Doppler Effect and gives us velocity along all axes
• Inertial Measurement Unit (IMU) uses magnetic fields to give us specific force along all axes and angular velocity along all axes
• Depth Sensor gives us our Z position in relation to the surface of the water

With our Camera we are able to locate competition objects and aid in countering drift in the robot’s position.

• ZED-2i Stereo Camera

Processing all this information is the NVIDIA Jetson AGX Xavier. It uses a ROS2 codebase to run our controller, process vision, and perform Simultaneous Localization and Mapping (SLAM). It makes its decisions using a BehaviorTree based autonomy system. Using all this Tempest is able to navigate through its environment and choose the best course of action.