Model-based Control
Moments of Inertia
https://en.wikipedia.org/wiki/Moment_of_inertia
https://en.wikipedia.org/wiki/List_of_moments_of_inertia
Ideal:
I_roll \approx I_yaw, I_pitch << I_roll, I_yaw
Interestingly, a sphere is not idael from the perspective of PID control/axis coupling.
Solid cuboid
I = 1/12 M ( a^2 + b^2 )
Camera Panasonic:
width | height | length |
---|---|---|
2.5 cm | 5.5 cm | 9 cm |
pitch: I \propto 2.5^2 + 5.5^2 = 36.5 -> 1
roll: I \propto 5.5^2 + 9^2 = 111.25 -> 3.05
yaw: I \propto 2.5^2 + 9^2 = 87.25 -> 2.39
Camera GoPro Hero5:
width | height | length |
---|---|---|
2.5 cm | 4.5 cm | 6.3 cm |
pitch: I \propto 2.5^2 + 4.5^2 = 26.5 -> 1
roll: I \propto 4.5^2 + 6.3^2 = 59.94 -> 2.26
yaw: I \propto 2.5^2 + 6.3^2 = 45.94 -> 1.73
Camera Mobius:
width | height | length |
---|---|---|
6 cm | 2 cm | 3 cm |
pitch: I \propto 6^2 + 2^2 = 40 -> 1
roll: I \propto 2^2 + 3^2 = 13 -> 0.325
yaw: I \propto 6^2 + 3^2 = 45 -> 1.125