When dealing with multiple cameras, we need to manage the ROS namespace properly. Additionally, it is desireable for us to create semantically relevant names for our sensors. We now walk through an example of using two cameras connected to the same machine.
The first thing we need to do is discriminate between the cameras by serial number.
$ rosrun royale_ros lscam
[
"0005-1212-0034-2109",
"0005-4804-0050-1916"
]
Lets assume we want to map the camera with serial number 0005-1212-0034-2109
to the name left_camera and the camera with serial number
0005-4804-0050-1916 to the name right_camera.
Let's bring up the left camera:
$ roslaunch royale_ros camera.launch serial_number:=0005-1212-0034-2109 camera:=left_camera
... logging to /home/tpanzarella/.ros/log/49cd49bc-8448-11e7-83d9-44850067bbb4/roslaunch-tuna-8180.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.
started roslaunch server http://tuna:45369/
SUMMARY
========
PARAMETERS
* /left_camera/initial_use_case: -
* /left_camera/on_at_startup: True
* /left_camera/optical_frame: left_camera_optic...
* /left_camera/poll_bus_secs: 1.0
* /left_camera/sensor_frame: left_camera_link
* /left_camera/serial_number: 0005-1212-0034-2109
* /left_camera/timeout_secs: 1.0
* /rosdistro: kinetic
* /rosversion: 1.12.7
NODES
/
left_camera (nodelet/nodelet)
left_camera_standalone_nodelet (nodelet/nodelet)
left_camera_tf (tf2_ros/static_transform_publisher)
ROS_MASTER_URI=http://localhost:11311
core service [/rosout] found
process[left_camera_standalone_nodelet-1]: started with pid [8198]
process[left_camera-2]: started with pid [8199]
process[left_camera_tf-3]: started with pid [8200]
[ INFO] [1503084078.559177248]: Loading nodelet /left_camera of type royale_ros/camera_nodelet to manager left_camera_standalone_nodelet with the following remappings:
[ INFO] [1503084078.566436535]: waitForService: Service [/left_camera_standalone_nodelet/load_nodelet] has not been advertised, waiting...
[ INFO] [1503084078.575066082]: Initializing nodelet with 8 worker threads.
[ INFO] [1503084078.587563108]: waitForService: Service [/left_camera_standalone_nodelet/load_nodelet] is now available.
[ INFO] [1503084078.639667319]: onInit(): /left_camera
[ INFO] [1503084078.648803944]: Probing for available royale cameras...
[ INFO] [1503084081.065769836]: Instantiated royale camera: 0005-1212-0034-2109
[ INFO] [1503084081.065804228]: Access level: 1
[ INFO] [1503084081.065950302]: Max number of streams: 2
[ INFO] [1503084081.358929963]: Caching intrinsic calibration...
[ INFO] [1503084082.022025691]: StreamId cache miss: 57082
Now the right:
$ roslaunch royale_ros camera.launch serial_number:=0005-4804-0050-1916 camera:=right_camera
... logging to /home/tpanzarella/.ros/log/49cd49bc-8448-11e7-83d9-44850067bbb4/roslaunch-tuna-8658.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.
started roslaunch server http://tuna:38370/
SUMMARY
========
PARAMETERS
* /right_camera/initial_use_case: -
* /right_camera/on_at_startup: True
* /right_camera/optical_frame: right_camera_opti...
* /right_camera/poll_bus_secs: 1.0
* /right_camera/sensor_frame: right_camera_link
* /right_camera/serial_number: 0005-4804-0050-1916
* /right_camera/timeout_secs: 1.0
* /rosdistro: kinetic
* /rosversion: 1.12.7
NODES
/
right_camera (nodelet/nodelet)
right_camera_standalone_nodelet (nodelet/nodelet)
right_camera_tf (tf2_ros/static_transform_publisher)
ROS_MASTER_URI=http://localhost:11311
core service [/rosout] found
process[right_camera_standalone_nodelet-1]: started with pid [8677]
process[right_camera-2]: started with pid [8678]
process[right_camera_tf-3]: started with pid [8679]
[ INFO] [1503084138.769005867]: Loading nodelet /right_camera of type royale_ros/camera_nodelet to manager right_camera_standalone_nodelet with the following remappings:
[ INFO] [1503084138.777704188]: waitForService: Service [/right_camera_standalone_nodelet/load_nodelet] has not been advertised, waiting...
[ INFO] [1503084138.793439312]: Initializing nodelet with 8 worker threads.
[ INFO] [1503084138.798616444]: waitForService: Service [/right_camera_standalone_nodelet/load_nodelet] is now available.
[ INFO] [1503084138.852212941]: onInit(): /right_camera
[ INFO] [1503084138.861103868]: Probing for available royale cameras...
[ INFO] [1503084141.117220436]: Instantiated royale camera: 0005-4804-0050-1916
[ INFO] [1503084141.117258562]: Access level: 1
[ INFO] [1503084141.117426667]: Max number of streams: 2
[ INFO] [1503084141.402304248]: Caching intrinsic calibration...
[ INFO] [1503084142.058688480]: StreamId cache miss: 57082
Lets now see what nodes are running:
$ rosnode list
/left_camera
/left_camera_standalone_nodelet
/left_camera_tf
/right_camera
/right_camera_standalone_nodelet
/right_camera_tf
/rosout
And, for exemplary purposes, lets see where the point cloud will be published:
$ rostopic list | grep -i 'cloud'
/left_camera/stream/1/cloud
/left_camera/stream/2/cloud
/right_camera/stream/1/cloud
/right_camera/stream/2/cloud
This short tutorial should provide you with the basis for successfully setting
up royale-ros-based multi-camera systems.