Lucas Haddad’s Work Log

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  • Post last modified:September 29, 2024
  • Reading time:6 mins read
  • Post category:Work Logs

9/13/2024

My sketch of what the project may look like at the end of the semester:

My to do list for the coming week (9/15-9/21):

Finish designing and build a functional buoyancy control prototype.

  • Built inside a common syringe
  • powered by an inexpensive servo
  • Rough responsive control with an IMU (if parts are available)
  • Able to be manually controlled

The unit will likely use a servo to turn a threaded rod which drives a syringe up and down, pulling water in and out of the robot. After filling the syringe half way with water, weights should be added to make the system neutrally buoyant. Thus allowing an equal range in positive and negative buoyancy adjustments.

My concerns for this week:

  • Finding parts to build the prototype

9/22/2024

What I was able to complete last week:

  • CAD design for buoyancy control unit

*currently waiting on parts for physical construction

My to do list for the coming week:

  • Construct the buoyancy control unit prototype
  • Research (and purchase?) IMU to test buoyancy control
  • Get an accurate/current weight distribution of the robot so I can determine optimal size and placement of the buoyancy control system

My concerns for this week:

  • Waiting on parts I ordered

9/29/2024

The operation of our device can be roughly illustrated in the diagram below:

The focus of my work had been on the buoyancy control system, a more detailed diagram of this system is shown below. The system pulls water in and out of a syringe to control the buoyancy of the robot. By placing the system in the nose of the fish, it can also be used to adjust the pitch of the robot. The system shown below uses magnets to transfer force from the threaded rod to the syringe plunger. This allows the plunger to travel along the full stroke of the syringe, since the threaded rod is located on the exterior of the syringe. When the rod is inside the syringe, the system is limited to 50% of the syringes original stroke (the rod cannot go through the plunger seal).

I plan for this system to operate in 2 states:

  • Autonomous Neutral Buoyancy Mode: maintains a stationary vertical position using feedback from the IMU.
  • Manual Control Mode: syringe motion is controlled via input from a controller.

What I was able to complete last week:

  • Received parts and began construction of the buoyancy control unit. Due to other responsibilities, I was unable to complete the construction.

My to do list for the coming week:

  • Finish assembling the buoyancy control unit.
  • Research (and purchase?) IMU to test buoyancy control
  • Get an accurate/current weight distribution of the robot so I can determine optimal size and placement of the final buoyancy control system

My concerns for this week:

  • Time, I have been very busy and need to adjust my responsibilities to allocate more time towards the project.