RoboSub Challenge

The 2022-2023 RoboSub challenge required a torpedo launcher, weight dropper, and object gripper in order to complete the autonomous underwater tasks.

Torpedo Launcher

I developed an underwater torpedo launcher that is accurate within 5 inches at 4 feet distance. I designed the torpedo launcher to use one servo to launch two torpedoes. If the servo rotates in one direction, it releases one torpedo which is launched using a compressed spring. If the servo rotates in the opposite direction, the second torpedo will be launched.

When designing the spring mechanism I conducted extensive calculations to ensure that the torpedoes would travel four feet at a reasonably high speed and accuracy. I used a damped mass-spring system to simulate the spring and torpedo with drag from the water. Using the release velocity from the spring, I calculated the trajectory of the torpedo underwater using a simplified torpedo geometry to approximate the drag coefficient. This allowed an informed decision of the ideal spring rate, max. load, and length.

Dropper Mechanism

I designed a dropper mechanism that can drop two weights accurately from a two foot distance into a container. Rotating the servo in one direction would drop a weight, and rotating it in the opposite direction would drop the second weight.

Rack and Pinion Gripper

The AUV had to grab a large, flat sided object from a flat surface. I designed a rack and pinion gripper in order to pick up these objects. Running the motor would rotate the gear, moving one gripper wall closer to the other, until it gripped the object.

Waterproofing

We used servos waterproof rated for splashes and short underwater periods, so further waterproofing was required. I researched and waterproofed each servo using mineral oil, O-rings, epoxy, and lubricant.

Autonomous Underwater Robot