Design, Build, Test, Iterate

Archive for February, 2012

Upcoming events?

The FIRST Autodesk Oregon Regional happens next Thursday through Saturday. A few of our OSU Robotics Club members, including myself, will be going up Friday morning to show off our various subteams. Mars Rover will be there as usual, but I wonder if our Aerial team can get something flying by then? Earlier tonight, the […]

Tricopter yaw mechanism, revision 2

My old implementation of the tricopter’s tail rotor yaw mechanism was a hack job. The yaw mechanism is arguably one of the tricopter’s biggest weaknesses with regards to ease of control. Most implementations that can be found online involve some combination of a servo and one or two ball joint linkages. I had used a […]

Kiwi drive videos

Just a few videos of my kiwi drive robot.

Kiwi drive robot, resurrected!

Two years ago, I started building a three-wheeled, omnidirectional, “kiwi drive” robot as a school project. For various reasons, I put the project on hold, while things like chemistry and flying machines distracted me. The parts sat in a drawer, unforgotten but largely ignored. ..Until last Monday.

Finally, flight!

My tricopter flies! Of course, I mean that very loosely, that it was airborne. Tuning the controller so the craft is actually controllable, however, is a task yet unfinished. In hindsight, my gains were much too low for free flight. Ground effect was therefore much more pronounced, and it took me a few tries before […]

How to correct the correction vector for an IMU

In a previous post, I explained how to correct for gyro drift by using the accelerometer’s reading of the gravitational acceleration vector. But how do we know the measured gravitational vector is accurate? Unless I build my tricopter with utmost precision and proper materials (i.e., not scrap wood cut with a handsaw), it’s impossible to […]

ESC configuration for multirotors — enable hard acceleration!

The factory defaults for the Mystery 40A ESCs I use on my tricopter are fine for RC planes but are not so good for multirotors because of their “soft acceleration,” which means the ESCs deliberately spin up the motors over the course of a half second or two. This is so that if I am […]