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Document MT0605P.2018.E
© Xsens Technologies B.V.
MTi User Manual
𝐺 = [
𝐺
1
0
0
0
𝐺
2
0
0
0
𝐺
3
]
𝐾
𝑇
= [
𝐺
1
0
0
0
𝐺
2
0
0
0
𝐺
3
] [
𝑎
1,𝑥
𝑎
1,𝑦
𝑎
3,𝑧
𝑎
2,𝑥
𝑎
2,𝑦
𝑎
2,𝑧
𝑎
3,𝑥
𝑎
3,𝑦
𝑎
3,𝑧
] + 𝑂
With
O
representing higher order models and temperature modelling, g-sensitivity corrections, etc.
Each individual MTi is modeled for temperature dependence of both gain and bias for all sensors and
other effects. This modeling is not represented in the simple model in the above equations, but is
implemented in the firmware with the temperature coefficient being determined individually for each MTi
device during the calibration process. The basic indicative parameters in the above model of your
individual MTi can be found on the “MT Test and Calibration Certificate” and in the MT Manager (MT
Settings dialog).
5.8.2 Calibrated delta_q and delta_v outputs
This output is coning- and sculling compensated strap down integrated data in the sensor-fixed
coordinate system (
S
) or (
O
). Note that the value of the output depends on the output frequency, as the
values are integrated over a specific time. Delta_q can also be noted as dq, delta_angle, del_q or OriInc.
Delta_v can also be noted as dv, delta_velocity, del_v or VelInc.
Table 14: Output specifications ∆q and ∆v outputs
Output
Unit
Delta_q (DataID 0x8030)
a.u. (quaternion values)
Delta_v (DataID 0x4010)
m/s
It is possible to multiply consecutive delta_q values to find the total orientation change over a specific
period. Note that this data is not drift free, as it has not been processed by the sensor fusion filters. Use
the orientation output for drift free orientation.
5.8.3 Calibrated inertial and magnetic data outputs
Output of calibrated 3D linear acceleration, 3D rate of turn (gyro) and 3D magnetic field data is in sensor-
fixed coordinate system (
S
) or (
O
). The units of the calibrated data output are as shown in Table 15.
Table 15: Output specifications inertial and magnetometer data outputs
Vector
Unit
Acceleration (DataID 4020)
m/s
2
Angular velocity (rate of turn) (DataID 0x8020)
rad/s
Magnetic field (DataID 0xC020)
a.u. (arbitrary units; normalized to earth field
strength)
Calibrated data has been going through Strapdown Integration and Inverse Strapdown Integration.
