Kalibr calibration realsensed435i -- multi camera calibration

Image download 、 Domain name resolution 、 Time synchronization please click Alibaba cloud open source image station

kalibr Calibration plate （ Chessboard ） Use elder martial brother's （ Long like this ）

Step one ： The establishment of a ROS Medium Kalibr Working space for , Create a ：checkerboard.yaml The file of , The content is ：

target_type: 'checkerboard' 

targetCols: 11                  // Number of inner corners 

targetRows: 8                  

colSpacingMeters: 0.02               

rowSpacingMeters: 0.02  

Step two ： Turn on and off the structured light

The default is to start the structured light , The binocular image will have many points , These points may affect the calibration , So you need to turn off the structured light .

Start at the terminal first

roslaunch realsense2_camera rs_camera.launch

New open terminal , function

rosrun rqt_reconfigure rqt_reconfigure

When opened, it will camera->stereo_module Medium emitter_enabled Set to off(0)

Step three ： determine realsense D435i Put it in the right place

New open terminal , function rviz

rviz

stay rviz Lieutenant general Global Option Medium Fixed Frame Choose... Later camera_link

Click on Add stay topic Select separately from

/camera/color/image_raw、/camera/infra1/image_rect_raw、/camera/infra2/image_rect_raw, open （ double-click camera） Add successfully .

Then align the calibration plate , Try moving realsense D435i, At the same time, make sure that the calibration board is always in the three images , Here's the picture

Step four ： Modify the number of camera frames （ The official recommendation is 4Hz, Although the actual frequency is not completely accurate , But it doesn't affect the result ）

kalibr When processing calibration data, the frequency shall not be too high , It's usually 4Hz, We can use the following command to change topic The frequency of , In fact, the original topic Turn into a new... With a new frequency topic, Actual test infra1 Is the corresponding left eye camera .

Use Ctrl+shift+T, Open a new terminal , One terminal runs one , Run respectively

rosrun topic_tools throttle messages /camera/color/image_raw 4.0 /color

rosrun topic_tools throttle messages /camera/infra1/image_rect_raw 4.0 /infra_left

rosrun topic_tools throttle messages /camera/infra2/image_rect_raw 4.0 /infra_right

Step five ： Recording ROS Data packets

Use Ctrl+shift+T, Open another new terminal to run ：

rosbag record -O multicameras_calibration /infra_left /infra_right /color

Back three topic It's after the frequency conversion topic, I recorded 3 minute , When recording, move towards the calibration board , Press down ctrl+c The end of the recording , When you see the current folder, you will see multicameras_calibration.bag file .

Step six ： Use Kalibr calibration

Activate the environment variable first

source ~/kalibr_workspace/devel/setup.bash

And then run ：

kalibr_calibrate_cameras --target checkerboard.yaml --bag  multicameras_calibration.bag --models pinhole-equi pinhole-equi pinhole-equi --topics /infra_left /infra_right /color --bag-from-to 10 100 --show-extraction --approx-sync 0.04

Last ：

The final result is three files ：

camchain-multicameras_calibration.yaml

report-cam-multicameras_calibration.pdf

results-cam-multicameras_calibration.txt

notes ： Possible problems

1、kalibr_calibrate_cameras： Command not found

resolvent ：

Recompile ：

~/kalibr_workspace$ catkin build -DCMAKE_BUILD_TYPE=Release -j8

Again ：

source ~/kalibr_workspace/devel/setup.bash

2、

File"/home/lab/kalibr_workspace/src/kalibr/aslam_offline_calibration/kalibr/python/kalibr_common/ConfigReader.py", line 234, in raiseError

raise RuntimeError( "{0}{1}".format(header, message) )

RuntimeError: [CalibrationTargetConfig Reader]: Could not read configuration from ../checkerboard.yaml

resolvent ： modify checkerboard.yaml The file is the above content （ Step one ）.

Link to the original text ：https://blog.csdn.net/weixin_45868890/article/details/123197364