This is just a small program that does not depend on the ROS framework that allows for communication with the xsens imus. Most code was taken from ethz-asl/ethzasl_xsens_driver package, but all version of ROS have been removed. In the main script there is a way to specify what measurements should be reported from the IMU. Currently the linear acceleration, angular velocity, magnetometer, and orientation are being recorded.
- mtdef.py - Contains all protocol variables needed
- mtdevice.py - Actual python driver, opens a serial port with the IMU
- mtnode.py - Wrapper that will try to get a new message from IMU as soon as possible
One can configure the IMU using a series of strings. This information can also be found in the bottom of the mtdevice.py file. One can then call mtdevice.get_output_config(args) to get the config file, and then finally configure the IMU by calling SetOutputConfiguration().
The format is a sequence of "<group><type><frequency>?<format>?"
separated by commas.
The frequency and format are optional.
The groups and types can be:
t temperature (max frequency: 1 Hz):
tt temperature
i timestamp (max frequency: 2000 Hz):
iu UTC time
ip packet counter
ii Integer Time of the Week (ITOW)
if sample time fine
ic sample time coarse
ir frame range
o orientation data (max frequency: 400 Hz):
oq quaternion
om rotation matrix
oe Euler angles
b pressure (max frequency: 50 Hz):
bp baro pressure
a acceleration (max frequency: 2000 Hz (see documentation)):
ad delta v
aa acceleration
af free acceleration
ah acceleration HR (max frequency 1000 Hz)
p position (max frequency: 400 Hz):
pa altitude ellipsoid
pp position ECEF
pl latitude longitude
n GNSS (max frequency: 4 Hz):
np GNSS PVT data
ns GNSS satellites info
w angular velocity (max frequency: 2000 Hz (see documentation)):
wr rate of turn
wd delta q
wh rate of turn HR (max frequency 1000 Hz)
g GPS (max frequency: 4 Hz):
gd DOP
gs SOL
gu time UTC
gi SV info
r Sensor Component Readout (max frequency: 2000 Hz):
rr ACC, GYR, MAG, temperature
rt Gyro temperatures
m Magnetic (max frequency: 100 Hz):
mf magnetic Field
v Velocity (max frequency: 400 Hz):
vv velocity XYZ
s Status (max frequency: 2000 Hz):
sb status byte
sw status word
Frequency is specified in decimal and is assumed to be the maximum
frequency if it is omitted.
Format is a combination of the precision for real valued numbers and
coordinate system:
precision:
f single precision floating point number (32-bit) (default)
d double precision floating point number (64-bit)
coordinate system:
e East-North-Up (default)
n North-East-Down
w North-West-Up
Examples:
The default configuration for the MTi-1/10/100 IMUs can be
specified either as:
"wd,ad,mf,ip,if,sw"
or
"wd2000fe,ad2000fe,mf100fe,ip2000,if2000,sw2000"
For getting quaternion orientation in float with sample time:
"oq400fw,if2000"
For longitude, latitude, altitude and orientation (on MTi-G-700):
"pl400fe,pa400fe,oq400fe"