Gravity Flag - Pepperl+Fuchs IMUF99 B20 Series Manual

Inertial Measurement Unit IMUF99*B20
Commissioning
5.9

Gravity Flag

Rotations about the gravity vector can't be detected in the angle output.
Technical-physical relations
• Regardless of the mounting position of the sensor, a rotation around the gravitational vec-
tor is not recognized as an angle change.
• If the mounting position or a previous movement of the application causes its measuring
axis to be parallel (±5°) to the earth's gravitational vector, then this measuring axis shows
a noisy behavior both in the idle state and during movements around the gravitational vec-
tor.
Note
This effect only refers to the output of the angle values. Acceleration and rotation rate values
are unaffected by this effect.
For these reasons, the sensor offers the functionality that this condition is automatically
detected and displayed. The sensor thus automatically recognizes whether and which measur-
ing axis is parallel to the gravitational vector and displays this via a flag.
In PDO 5 (angle output), the content of byte 8 with Mapping ID 11 corresponds to the flag for
displaying which measuring axis is parallel to the gravitational vector. The content of byte 8 can
assume the following values with the appropriate meaning.
Content Byte 8
Mapping ID 11
HEX
00
01
02
04
Table 5.11
Content Byte 8 x-Gravity
Mapping ID 11 Flag
Binary
000 Not active
001 Active
010 Not active
100 Not Active
y-Gravity z-Gravity
Flag Flag
Not active Not active
Not active Not Active
Active Not active
Not active Active
Description
No measuring
axis currently
parallel to the
gravitational
vector
The x-axis
(Roll) is cur-
rently parallel
to the gravita-
tional vector
The y-axis
(Pitch) is cur-
rently parallel
to the gravita-
tional vector
The z-axis
(Yaw) is cur-
rently parallel
to the gravita-
tional vector
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