This library is written independent of any specific IMU. The idea is you pass in the appropriate measurements and error terms from your IMU and get the desired output.
This is still under heavy development
The suggested way to install this is via the pip command as follows:
pip install ins_nav
To submit git pulls, clone the repository and set it up as follows:
git clone https://github.com/MomsFriendlyRobotCompany/ins_nav
cd ins_nav
poetry install
ins_nav.wgs84contains a bunch of useful constants: semi-major axis, gravity, etcins_nav.ahrscreates an attitude and heading reference system (AHRS) using accelerometers, gyroscopes, and magnetometersTiltCompensatedCompasscontains the mathematics of an IMU with accelerometers, gyroscopes, and magnetometersins_nav.transformshas a bunch of reference frame conversions:ecef2llh,llh2ecef, etcins_nav.errorshas functions to estimate the horizontal errors given an IMU's bias, mis-alignment, and random walk noise
- ECI: Earth-centered Inertial is an
inertial frame where Newton's laws of motion apply. It has its origin at the center of the
Earth with:
- x-axis in the direction of the vernal equinox
- z-axis is parallel to the rotation of the Earth
- y-axis completes the right-handed coordinate system
- ECEF: Earth-centered, Earth-fixed has the same origin as ECI, but rotates with the Earth and the x-axis points towards the zero/prime meridian. The ECEF frame rotates at 7.2921E-5 rads/sec with respect to the ECI frame
- LLA(H): Latitude, Longitude, Altitude(Height) is similar to the ECEF frame, but is the frame historically used for navigation
- ENU: East North Up a local navigation frame, where up and the z-axis align, but clockwise right turns are negative
- NED: North East Down a local navigation frame, where up and the z-axis are opposite, but the direction of right (clockwise) turns are in the positive direction and is the standard vehicle roll-pitch-yaw frame
- lat_lon_parser allows you to convert between
measurements formats like
-45 deg 12' 36.0 sec,45.21 W, and-45.21easily - nvector has a lot of capability
- navpy appears to be simple grad student work but code is well referenced (BSD)
- navigation does GPS navigation and way points
- extended kalman filter
- navigation equations
- error model
| Date | Version | Notes |
|---|---|---|
| 2020-03-28 | 0.6.0 | moved to poetry |
| 2019-07-05 | 0.5.1 | cleanup and new functions |
| 2017-07-07 | 0.0.1 | init |
Copyright (c) 2017 Kevin J. Walchko
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