Clone kalibr into a ROS workspace, build, and source.
git clone git@github.com:ethz-asl/kalibr.git
See their wiki for more information about installation and dependencies (unfortunately dependency information is only provided for ROS indigo/14.04, but it works on melodic/18.04). At the least, you probably need
sudo apt-get install flex
pip2 install python-igraph
Installing python-igraph take a long time.
Go to workspace and build as release
catkin build -DCMAKE_BUILD_TYPE=Release
Use an April tag or checkerboard grid that we have at PERCH, and take a bag with the camera pointing at it.
First bag (For camera intrinsics):
- The camera system is fixed and the calibration target is moved in front of the cameras to obtain the calibration images.
Second bag:
- Try to excite all IMU axes (rotation and translation)
- Avoid shocks, especially at the beginning/end when you pick up the sensor
- Good illumination
- Keep the whole grid in the frame (watch playback on RViz)
To create these bags, in the home directory of the drone, run
sudo -s
roscd snavquad_interface/scripts
./tmux_calibration.sh
Once the tmux loads, choose the correct camera tab and start the cooresponding camera drivers
Get the drone in position and manually start the bagging script by hitting Enter in the Bagging tab. The bagging script will record all the cameras if they are launched.
roscd snavquad_interface/config/kalibr
kalibr_calibrate_cameras \
--bag [first bag path] \
--topics MVSampleVISLAMEagle/snap_cam_output_image \
--models pinhole-radtan \
--target aprilgrid.yaml
This will output camchain-%BAGNAME%.yaml: Results in YAML format. This file is used as an input for the camera-imu calibrator.
roscd snavquad_interface/config/kalibr
kalibr_calibrate_imu_camera --bag [second bag path] \
--cam camchain-[first_bag_name].yaml \
--imu snap_imu.yaml \
--target aprilgrid.yaml
See Kalibr wiki for more information if it's not working.