‫Welcome back.
‫So I want to talk a little bit more about those conventions, what I want you to understand is that
‫the drones attitude is not different, depending on which convention you choose.
‫The drones attitude is what it is.
‫And now you simply have to describe the altitude of the drone.
‫And for that, you have different ways to do it.
‫You have 24 different ways to describe the drones attitude if you use rotation matrices to describe
‫it.
‫You have 12 ways if you rotate about the fixed inertial frame axis and then you have 12 ways when you
‫rotate about the moving body frame axis, but the drones altitude itself stays the same is just you
‫have different conventions to describe the same thing.
‫It's like describing some kind of distance either in meters or in feet.
‫It's like either you use Cartesian coordinates to describe some kind of position or polar coordinates.
‫So, for instance, if you choose to describe a drone's attitude with an inertial X, Y, Z convention
‫where you first rotate about the inertial X axis, then about the inertial Y axis and then about the
‫initial Z axis, then your Fifita and BPCI Angles will have some kind of values.
‫But if you choose to describe the same thing with an inertial Z, Y, X convention where you first rotate
‫about the inertial axis, then about the initial Y axis and then about the inertial x axis, then those
‫angles will have different values.
‫But again, the drones attitude is still the same is just you are describing this additive in a different
‫way.
‫And that's what conventions are all about.
‫It's about having different ways to represent the same thing.
‫Either you represent the attitude of the drone by rotating about the inertial X, Y, Z axis, where
‫you have 12 different ways to do it, or you represent the same attitude.
‫But by rotating about the moving body frame axis for which you also have 12 different ways to do it.
‫So that's that.