Oogway

Built on top of Foxglove Studio using the React Material UI library, the Duke Robotics GUI features a modular and modern design and allows us to easily monitor and control our AUV during pool tests. We can receive real-time updates on the status of our onboard computer, sensors, thrusters, and battery. We can observe the performance of the czontrols system and tune PID constants on-the-fly. We can use a joystick to control the robot directly. Individual panels are organized into layouts and easily deployed using a custom CLI. The GUI also supports replaying recorded ROS bag files for offline debugging and analysis.

Detection

The computer vision (CV) system uses stereo and monovision inputs from both our DepthAI and USB cameras to locate items underwater to complete our underwater tasks. For simpler prediction tasks, we employ HSV filtering and contour matching to identify the buoy, path markers, and bin. For more intricate images encountered in the gate, torpedo, and octagon tasks, we utilize YOLO object detection models. Our enhanced CV pipeline seamlessly integrates these methodologies, dynamically adjusting to optimize detection speed and accuracy for various tasks.

Oogway relies on many sensors to track both external and internal conditions.

Our primary sensors determine the robot’s state, that being its 6 degrees of freedom: x, y, z, roll, pitch, yaw. Our IMU, DVL, gyroscope, and pressure sensor are fused in software to provide an accurate state. The IMU, DVL, and gyroscope all have their own direct UART serial connection to the PC, whereas the pressure sensor is read through an Arduino and sent to the main ROS node over USB.

Oogway has two sonars onboard, both of which are connected to the computer’s USB.

We also have an internal voltage sensor to monitor the battery and dynamically adjust thruster speed, a temperature sensor to monitor capsule heat, and a humidity sensor to detect water ingress. We also read data from these three internal sensors with an Arduino.

Oogway has four cameras that we use for CV and monitoring. Two cameras are simple USB cameras rated for underwater, and two are sophisticated stereoscopic cameras with internal processing. These cameras represent a significant demand for both our power and data systems.

The stereoscopic cameras are used to run complex ML models that help us We also utilize downward-facing cameras to track path markers on the pool floor.

Oogway features eight thrusters, and the electrical team provides the hardware abstraction layer used by the controls system.

Each thruster requires a precise PWM signal from the PC, which is challenging due to hardware inconsistencies measured in our ESCs. To manage this, we communicate with an Arduino Nano Every over serial, which interfaces with an I2C multiplexer to control all eight thrusters. The ESC offsets are then handled through a software abstraction layer.

In addition to the thrusters, Oogway is equipped with two servos, one to control the marker dropper and one to control the torpedo launcher. When ROS sends the appropriate commands, we can independently deploy team markers and fire torpedoes as needed.

This year, we newly integrated a Water Linked M16 acoustic modem into Oogway to enable underwater communication with other robots. The modem’s omnidirectional capabilities allow Oogway to send and receive data from anywhere in the pool without needing to reorient, making it ideal for collaborative, multi-robot tasks.

To support this integration, we developed a custom interface that links the modem to the onboard computer. This interface manages serial communication, publishing incoming messages to a ROS topic and sending outgoing data through a ROS service, as well as ensuring seamless operation within our modular, robot-agnostic system.

The primary goals for all component mounts on Oogway are flexibility and rapid prototyping. Oogway’s aluminum rails allow us to move components around easily to optimize for factors such as buoyancy and placement of sensors. This year, this came in handy for the hydrophone mounts, which underwent several different designs and locations as the acoustics subteam developed their code. 

We primarily use 3D-printed mounts to keep Oogway lightweight and allow for updated designs to be fabricated consistently and quickly. The battery mount, for example, broke frequently during last year’s competition. This year, we were able to quickly prototype and test new designs and print backups just in case. We also designed several new parts this year, such as a marker dropper, two new sonar mounts, three new camera mounts, and a new adjustable buoyancy system.

We added actuators to Oogway for the first time this year. The marker dropper mechanism uses Blue Trail Engineering’s waterproof servo to hold up to two markers in place, and a rotation to either side allows these markers to be released. This gives us the flexibility to choose when the markers should be dropped and how many should be dropped at a time. 

While not yet on Oogway, we are also prototyping a torpedo launcher using the same waterproof servo, which will be responsible for releasing the torpedoes. Like with the marker dropper, we aim to use one servo to control both triggers independently to give us the most flexibility during a run.