Aruco with Logitech C922

Logitech C922

• 1080p @ 30 fps
• 720p @ 60 fps
• 3 Mpx
• diagonal field of view 78°
• autofocus

usb_cam driver

First, a camera driver needs to be installed - wiki

sudo apt-get install ros-melodic-usb-cam

Check for camera device (ls /dev, look for new videoX) and run the driver (/dev/video3 replace with the correct device):

rosrun usb_cam usb_cam_node _camera_name:='usb_cam' _camera_frame_id:='usb_cam' _video_device:='/dev/video3' _image_width:=1920 _image_height:=1080

You can check the video stream in RViz (Add > By topic > /usb_cam/image_raw/image).

Calibration

With this procedure, the camera's intrinsic parameters are obtained.

Install camera_calibration package - wiki

sudo apt install ros-melodic-camera-calibration

Run calibration node

rosrun camera_calibration cameracalibrator.py --size 11x15 --square 0.015 image:=/usb_cam/image_raw camera:=/usb_cam

Aruco markers

Aruco markers are used to determine the pose of an object equipped with proper markers.

For this fiducials and aruco_detect packages are used.

Install packages:

sudo apt-get install ros-melodic-fiducials
sudo apt-get install ros-melodic-aruco-detect

Generate markers (14 cm side; for anything else, tune the .py file):

rosrun aruco_detect create_markers.py 100 110 fiducials.pdf

Use the aruco_detect package to detect aruco markers. Set the correct parameters for the camera.

roslaunch aruco_detect aruco_detect.launch camera:=/usb_cam image:=image_raw fiducial_len:=0.14 

roslaunch aruco_detect aruco_detect.launch camera:=/camera/color fiducial_len:=0.14 

Pose of the marker is returned in the /fiducial_transforms topic. Markers can also be seen with

roslaunch fiducial_slam fiducial_rviz.launch