MATE 2024

SeaHawk II

Explorer First Place Overall MATE World Championship

The SeaHawk II is our third-generation ROV, engineered for the 2024 MATE ROV Competition. This ROV was completely redesigned from scratch, with no iterations from the SeaHawk (2023). However, we learned many valuable lessons from previous generations, which informed our strict design constraints and contributed to the robust and successful SeaHawk II.
With a clear understanding of our design requirements, we transitioned from our previous research frame to a frame made from sheet-cut aluminum. This change greatly improved the mechanical reliability of the ROV and allowed us to reduce weight. Additionally, we moved away from off-the-shelf pressure vessels and machined our own electrical box out of aluminum. We designed a stack of custom PCBs, significantly enhancing reliability and performance compared to last year. We also dedicated considerable time to developing our tooling systems, including the main claw, rock scraper, and quick-release tooling system.
Like its predecessor, SeaHawk II’s software is based on the Robot Operating System (ROS). ROS provides tools and software libraries specialized for development of robotics applications. While we continued using ROS, the software evolved significantly. We planned on a light refactor but ended up doing a near-complete rewrite of last year’s software. Major changes included a custom dashboard, a reliable data-driven kinematics system, and micro-ROS for integrating a Raspberry Pi Pico. The control system consists of a surface pilot interface as well as an onboard Raspberry Pi 4 (a single-board computer) and a Pi Pico (a microcontroller). Pilot inputs from an Xbox controller and keyboard are read, interpreted, then sent to the onboard Pi. PWM drivers on the Pico drive the motors. To enhance the piloting experience and ease of use, a variety of feedback including camera displays and sensor readings are displayed by the completely custom dashboard graphical user interface. All software for this project is open source and can be found on our GitHub.


Technical Report

ROV Features

  • 1 The propulsion system consists of eight strategically positioned Blue Robotics T200 thrusters encased in custom 3D-printed housings. The thrusters are arranged to enable six degrees of freedom. Input from the control system allows variable thrust to optimize precision. This design enables the robot to navigate complex environments with agility, crucial for delicate tasks like ecosystem restoration.
  • 2 SeaHawk II is equipped with three tactically placed cameras which provide the pilot with a comprehensive view of the robot’s underwater environment. The primary camera is mounted on a servo which allows the pilot to actively adjust the field of view. The camera at the back of the ROV permits reverse navigation, enhancing maneuverability. The downward facing camera gives the pilot an aerial view of the environment.
  • 3 The articulating pneumatic claw is engineered for dynamic and reliable usage. It is mounted on the front of SeaHawk II, within view of the primary camera. The claw is pneumatically actuated by the custom manifold which is supplied air through the pneumatic tube in the tether. The versatile custom jaws of the tool enable SeaHawk II to retrieve and relocate a wide range of objects, from brain coral to acoustic receivers.
  • 4 The multifunction rear claw was designed for lifting heavy loads and deploying data collection devices, such as the irrigation system framework and the coastal pioneer array. With the claw bolted closely to the center of mass, heavy loads are easier to pick up. The claw is also specially shaped to allow for more precise motions, which aids itself to tasks such as the collection of sediment samples.
  • 5 The ROV features a waterproof digital temperature sensor with accuracy of ±0.5°C with a range of -55 to 125°C. These temperature readings are collected every 0.1 seconds and displayed to the pilot dashboard. The task “Measure the temperature to check the SMART cable sensor readings'' requires accurate measurements to verify the functionality of a SMART repeater's temperature sensor.
  • 6 The valve coupler is designed so that the ROV can interact with the valve on the irrigation device and complete the MATE 2024 task “Activate the irrigation system”. It is mounted to a custom quick release (6.a) for modularity enabling rapid swapping of various tooling. It was designed to interface with the valve’s geometry, all while providing a clear view of the rotation to the pilot.
  • 7 Deploying submarine cables is a complicated action, for this reason a specialized cable deployment spool was designed to deploy Science Monitoring And Reliable Telecommunications (SMART) Subsea Cables through waypoints. The SMART cable is round about the spool to prevent tangling during deployment and released by a motorized mechanism at a steady rate. This tool is also attached to the quick release.
  • 8 The vertical profiling float (VPF) autonomously ascends and descends the water column collecting pressure data. Upon resurfacing, packets are transmitted via LoraWan Radio modules to the deckside. The data is plotted as a graph of depth in meters vs the sample time. GO-BGC floats also collect various data to gather observations of ocean biochemistry and ecosystems.

Safety Features

SeaHawk II is equipped with a suite of safety features that reduce the risk of injury and provide streamlined operation. To protect ROV operators and the marine environment, all tooling edges are chamfered and thrusters are enclosed in custom 3D-printed thruster shrouds that block objects larger than 12 mm. The 24m tether is equipped with a master fuse and strain relief webbing. An overvoltage protection circuit prevents damage to electronics in the event of a voltage spike. Various tooling is powered by pneumatics (pressurized air) which can cause severe injury if not safely implemented. For this reason, the air prep system valve purges potentially dangerous pressure build-up, and operators must be familiar with the dangers and correct usage of pneumatic power. Advanced software limits thruster power and monitors the system and sensors for abnormalities in which case the pilot is notified and prompted to use the kill switch for immediate shutdown.

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