First of all,it could be useful to define some references used along the project.
Let’s start to name the 4 motors using a number and a orientation reference:
I’ll call motor0 ( M0) ,motor1 (M1) ,motor2 (M2) e motor3 (M3).
(the index starts from 0 because it is more useful when programming in python: an array index starts from 0)
Looking the quadcopter from above , the motors are numbered in counterclock wise.
Considering a cartesian reference system:
- positive X is exiting M0 with direction M2-M0
- positive Y is exiting M1 with direction M3-M1
- positive Z is exiting from the motor plan
In aviation, they are using the following terminology:
- trottle: vertical movement
- roll: rotation along the fuselage
- pitch: trasversal rotation respect the fuselage , along the wings.it is also called nick.
- yaw: rotation perpendicular the fuselage and the wings.
Considering the simmetry of the quadcopter, we can assume:
- roll: rotation along X
- pitch: rotation along Y
- yaw: rotation along Z
Dimensions are always in mm ,degrees, seconds