Kauai Labs navX-MXP User Manual page 65

Guidance
Terminology
Pitch, Roll and Yaw
Pitch, Roll and Yaw are measures of angular rotation about an object's center of mass, and
together provide a measure of "orientation" of that object with respect to an "at rest" position.
When units of degrees are used, their range is from -180 to 180 degrees, where 0 degrees
represents the "at rest" position of each axis.
Axis Orientation relative to
object's center of mass
Left/Right
X (Pitch)
Forward/Backward
Y (Roll)
Up/Down
Z (Yaw)
Important Note: Pitch, Roll and Yaw angles represent rotation from the "origin" (0,0,0) of a
3-axis coordinate system. navX-MXP Pitch and Roll angles are referenced to earth's gravity –
so when navX-MXP is flat, Pitch and Roll angles should be 0.
The Yaw angle is different – Yaw is not referenced to anything external. When navX-MXP
startup calibration completes, the Yaw angle is automatically set to 0 – thus at this point, 0
degrees represents where the "head" of the navX-MXP circuit board is pointing. The Yaw angle
can be reset at any time after calibration completes if a new reference direction is desired.
Linear Acceleration
Linear Acceleration is a measure of the change in velocity in a specific direction. For example,
when a car starts from a standstill (zero relative velocity) and travels in a straight line at
increasing speeds, it is accelerating in the direction of travel.
Axis Orientation
Left/Right
X
Rotational Motion
+ Tilt Backwards
+ Roll Left
+ Clockwise/ – Counter-
wise
Linear motion
– Left / + Right
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