Monday, July 17, 2023

Balancing Leg

It balances!

The inertia changes significantly as the "body" moves up and down the leg - for the controller, I got feedback gains with LQR for the maximum and minimum extension cases, and linearly interpolate between those gains as the leg extends.

Tuesday, July 4, 2023

Leg + reaction wheel doing stuff

Running off a bench supply and offboard micro, controlling with a joystick.  There's an IMU attached too, so hopefully soon it'll be doing some 1-DOF balancing:

Tuesday, April 18, 2023

New capacitor for Yottacoil

Another CPW, another round of tesla coiling.  Last time the primary capacitor caught on fire, so I helped Michael and Austin cobble together a new one out of the Eurofarad caps the coil originally used.  I designed some bus bars and MITERS undergrads got them waterjet cut for us.

216 M6 socket head cap screws and 36 crimps later:

Successfully ran 2 evenings with 0 capacitor fires and 1 boost converter fire:

Saturday, February 11, 2023

Reaction wheel assembly

Still needs a motor, of course, but it's taking shape

Someone asked what the step on the inside of the reaction wheel was for:

Sunday, September 25, 2022

Mini Cheetah Clone First Test Drive

 One of the Chinese mini cheetah clone manufacturers was nice enough to send me one.  Stay tuned for a  detailed (non-destructive) teardown.

Monday, August 29, 2022

More Coiling

Once again Mike's tesla coil worked flawlessly - at least until someone tripped over the extension cord powering a fan cooling the primary capacitor bank.  We didn't notice until the capacitor bank burst into flames.


Sunday, June 26, 2022

First outdoor tests of the screw mechanism!

 Gremlins eradicated - USB hubs are  bad, don't use them:

"Only" ~3.3 meters in this test - not maxing out the motor/mechanism yet, there's still some motor control tuning to do.  And probably another round of transmission ratio optimization once the actual robot mass and inertia get finalized.

Tuesday, June 21, 2022

Finished Test Fixture

A robot-weight steel puck:

Test setup outside, before being beset by electrical gremlins:

Tuesday, May 31, 2022

Monday, May 9, 2022

More Screw Mechanism Testing

 Now controlled over CAN and USB, using a gui based on the espresso machine software

The the USB communication plus Python GUI gives me nice live-plots and logs.  Here's a plot of the fast position steps: