LPMS-B2 Series Hardware Manual ver. 1.0
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3.
Coordinate
The LPMS sensor calculates the orientation difference between a fixed sensor
coordinate system
(S)
and a global reference coordinate system
(G)
. Both coordinate
systems are defined as right-handed Cartesian coordinate systems. The sensor
coordinate system
(S)
is constructed as following images.
Fig. 3.1. Sensor coordinates of LPMS-B2 and LPMS-B2 OEM
The global reference coordinate system
(G)
can be divided into two different
cases. While the orientation calculation is using all acceleration, gyroscope and
magnetic data (sensor filter mode set at acc+gyr+mag),
(G)
system is defined as
following:
•
X positive when pointing to the magnetic north
•
Y positive when pointing to the magnetic west
•
Z positive when pointing up (gravity points vertically down with -1g)
While the orientation calculation is using only acceleration and gyroscope data
(sensor filter mode set at acc+gyr),
(G)
system is defined as following:
•
X positive aligned to ground plane horizontal projection of x axis of
(S)
when
sensor powered on
•
Y positive based on right-handed Cartesian coordinate definition
•
Z positive when pointing up (gravity points vertically down with -1g)
X
Z
Y
Z
Y
X
