Use Phidgets IMU compass to obtain orientation

UTRA-ART / SLAM-1920

SLAM and Navigation on ROS Kinetic

https://utra-art.github.io/SLAM/

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Use Phidgets IMU compass to obtain orientation #87

Closed erickmu1 closed 4 years ago

erickmu1 commented 4 years ago

Description:

phidgets_imu node does not publish orientation, but we can fuse it from the magnetometer using imu_magwick_filter

Goals:

[x] Obtain orientation from phidgets IMU ros topic

Acceptance Criteria:

[x] phidgets IMU ros topic publishes orientation
[x] Orientation is consistent with earth reference frame
[x] Imu topic is updated in all our packages appropriately

Notes:

If this works, then I purchased a second IMU for no reason...

erickmu1 commented 4 years ago

Resources:

erickmu1 commented 4 years ago

To get the magnetic field and declination given your location, use this site: https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#igrfwmm

For Toronto, ON, Canada I got:

Magnetic Field (ENU): [-3 336.9, 18 497.0, -50 226.4] nT
Magnetic Declination: -10 degrees

Observation: when applying all these location specific magnetic properties, the phidgets imu (1044_1) yaw = 0 orientation seems to be South [assuming that the side with the USB connector is its "backwards"]

*Need to double check whether the 0 or 1 direction (painted on imu) is the imu's forward (currently assuming 1 is forward)

erickmu1 commented 4 years ago

Update: The axes on the phidgets imu (top side) are called Axis-0, Axis-1, and Axis-2. The correspondence b/w phidgets axes and xyz are as follows: Axis-0 == x, Axis-1 == y, Axis-2 == z such that they obey the right hand rule.

Hence, the above magnetic properties ensure that yaw = 0 when Axis-0 (x-axis) points East at Toronto, ON, Canada, which is what robot_localization requires (satisfying REP-103).