If you were somehow dropped to a random location in your hometown, you would most likely be able to orient yourself based on landmarks and other sensory inputs of your surroundings. Even if you were dropped into an unfamiliar neighborhood, you could probably read street signs and guess at your location with a certain probability […]

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 […]

Gyroscopes do not measure acceleration, so they obviously cannot be used to calculate the direction of gravity. In other words, we can use gyro outputs to calculate an estimation of the direction cosine matrix, but the estimate will drift over time. A 3-axis accelerometer can be used to correct the roll and pitch drift, which […]

In a sentence, a direction cosine matrix is a 3×3 matrix containing the cosines between each of the 9 possible pairs of axes of two separate Cartesian coordinate systems. In the context of inertial measurement units in robotics applications, a 3D vector could be represented in either the global (earth) or the body (local) frames […]

The code involves a lot of math that I don’t understand! They never taught rotation matrices in high school. This post is just to share that I haven’t fallen asleep or anything. Okay, more honestly, I’ve just started coding again after a month of chemistry. It was still fun! Check out my (slow) progress on […]