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The cob_camera_sensors package is a collection of ROS compatible drivers for the cameras installed on Care-O-bot 3. These include two color cameras (either of type AVT Pike C145 or AVT Prosilica GC1380CH) and one Swissranger 4000 time-of-flight sensor from Mesa Imaging or the Microsoft Kinect sensor. All camera types are supported for Windows and Linux. To enable Windows compatibility, remove all -D__LINUX__ flags from CMakeLists.txt located at cob_driver/cob_camera_sensors. The two Prosilica GC1380CH are natively supported by ROS with the prosilica_camera package. The binaries of the prosilica_camera package are executed within the related launch files. The same holds for the Kinect whose driver is located in the openni_camera package.

Setting the camera parameters for the AVT Pike C145 and Swissranger 4000 is different from the suggested ROS standard. Instead of setting all parameters within the ROS launch file, camera specific parameters are set within IPA specific configuration files. This originates from IPA internal requirements to maintain backward compatibility to existing components. The ROS launch file only holds parameters related to the camera setup (e.g. specifying the used camera types) and a link to the IPA internal configuration file.

Quick launch guide

In order to launch the camera nodes, do the following (Replace cob3-2 with your personal Care-O-bot identifier)

For running all cameras

export ROBOT=cob3-2
roslaunch cob_camera_sensors all_cameras.launch

For running the left or right color cameras

roslaunch cob_camera_sensors left.launch
roslaunch cob_camera_sensors right.launch

For running the depth imaging camera

roslaunch cob_camera_sensors cam3d.launch

In order to check if everything is running launch the image viewer

To show the color images

rosrun image_view image_view image:=/stereo/left/image_color

and

rosrun image_view image_view image:=/stereo/right/image_color

For quitting do not close the viewer window, but hit CTRL-C on your console

To show the time-of-flight images

roslaunch cob_camera_sensors tof_camera_viewer.launch

For quitting do not close the viewer window, but hit CTRL-C on your console

Code API

/*12.name= /sr4000/image_grey 12.type= sensor_msgs/Image 12.desc= Intensity images of tof camera 13.name= /sr4000/image_xyz 13.type= sensor_msgs/Image 13.desc= XYZ data of tof camera 14.name= /sr4000/camera_info 14.type= sensor_msgs/CameraInfo 14.desc= Camera intrinsics of tof camera */

cob_camera_sensors

Provides access to the two color cameras and the time-of-flight sensor mounted on Care-O-Bot's head module.

Published Topics

/stereo/left/image_color (sensor_msgs/Image)

• Color images of color camera

/stereo/left/camera_info (sensor_msgs/CameraInfo)

• Camera intrinsics of color camera

/stereo/right/image_color (sensor_msgs/Image)

• Color images of color camera

/stereo/right/camera_info (sensor_msgs/CameraInfo)

• Camera intrinsics of color camera

/cam3d/depth/camera_info (sensor_msgs/CameraInfo)

• Camera intrinsics of depth camera

/cam3d/depth/image (sensor_msgs/Image)

• single channel floating point (float32) depth image, containing the depth in meters

/cam3d/depth/points (sensor_msgs/PointCloud2)

• point cloud without color information

/cam3d/rgb/camera_info (sensor_msgs/CameraInfo)

• Camera parameters for the RGB camera (only available with Kinect)

/cam3d/rgb/image_color (sensor_msgs/Image)

• RGB image (only available with Kinect)

/cam3d/rgb/image_mono (sensor_msgs/Image)

• Intensity images of Swissranger camera or grayscale image of Kinect

/cam3d/rgb/points (sensor_msgs/PointCloud2)

• point cloud containing RGB value for each point (only available with Kinect)

Parameters

Parameters

~ip_address (str, default: 169.254.47.10)

• URL defining which camera to connect to with which IP address.

~trigger_mode (str, default: streaming)

• Sets the trigger mode.

IPA configuration files

The IPA configuration file is located at cob_driver/cob_camera_sensors/common/files in a folder related to your sensor setup e.g. cob3-1 or cob3-2. The configuration is XML-based. It holds one XML-tag for each camera e.g. <AVTPikeCam_0> for a AVT Pike C145 camera. The number within the tag-name is used to differentiate several camera of the same type. Here is an excerpt from the IPA configuration file of one of our Care-O-bots.

<!-- Camera sensors initialization file -->
<LibCameraSensors>

<AVTPikeCam_0>
  <!-- Holds the 64-Bit GUID of a connected node -->
  <!-- A GUID consists of a 32-Bit high part that holds the VendorId (Highest 24 Bits) -->
  <!-- and the ChipIdHigh (8 Bits) and a 32-Bit low part that holds the ChipIdLow. -->
  <!-- The GUID is unique for all FireWire devices on the world. -->
  <GUID high="000A4701" low="10077005" />

  <!-- The master initializes and releases the camera library and is -->
  <!-- respnsible for emitting the trigger signal to other cameras -->
  <!-- The slave is synchronizing its image acquisition with the trigger signal -->
  <!-- Valid roles: MASTER oR SLAVE -->
  <Role value="MASTER" />

  <!-- Valid values: appropriate framerte or AUTO and DEFAULT -->
  <FrameRate fps="3" />

    <!-- Valid values: FORMAT_0, FORMAT_1, FORMAT_2 ,FORMAT_7, DEFAULT-->
  <VideoFormat type="FORMAT_7" />

  <!-- Valid values: MODE_0 - MODE_7, DEFAULT -->
  <VideoMode type="MODE_0" />
  ...
<AVTPikeCam_0/>
<LibCameraSensors/>

Each tag within the IPA configuration file has a short explanation of its functionality. Please feel free to examine one of the Care-O-bot configuration files to get an impression of the possible settings.

Camera intrinsics may be set for each camera within the designated tags. The information is later published with the images using the ROS Camera Publisher from the image_transport package. The user has the possibility of specifying different intrinsic for one camera. This is related to stereo vision, where intrinsics are optimize to fit to another camera. Within the ROS node that publishes camera images, the non-optimized intrinsic are published with the images. Extrinsic specify the rotation and translation relative to another camera. These parameters are not yet published and for IPA internal usage only.

For each camera there is also a related <VirtualXXXCam_X> tag. This is also related to backward compatibility issues and not used within ROS. Originally, it provided support for loading saved image data from disk and using it as if it came from a real camera device. However, ROS already provides more sophisticated means to record and play back data using rosbag and bag files.

ROS launch files

ROS launch files are located in cob_driver/cob_camera_sensors/ros/launch and hold information about the overall sensor setup not related to a specific camera. There is a launch file to start each camera independently (cam3d.launch, left.launch, right.launch) and a launch file to start all Care-O-bot cameras at once (all_cameras.launch). Before you can start these launch files, you have to specify your robot id via export ROBOT=cob3-1 for example. Each launch file specifies the location of the related IPA configuration file and the used color camera or time-of-flight camera type. The robot specific launch and configuration files are located in the cob_driver/cob_camera_sensors/ros/launch/$ROBOT folders. The following camera types are supported:

• CAM_SWISSRANGER - For Mesa Swissranger 3000/4000 time-of-flight camera

• CAM_AVTPIKE - For AVT Pike 145C color camera

• Prosilica GC1380CH GigE - Through the ROS driver

• Kinect - Through the ROS driver

The Prosilica GC1380CH color camera is supported through the ROS prosilica_camera package. To get more information, have a look at their tutorial. The camera specific launch files have an additional parameter specifying the camera's ID which is related to the number within the tag-name in the IPA configuration file e.g. <AVTPikeCam_0>.

Knowing the fundamentals, we are now ready to start up the cameras. The following table sums up the built-in cameras for each Care-O-Bot.

AVT Pike C145

A detailed guide for configuring and starting the stereo pair of Pike C145 cameras can be found in the Care-O-Bot AVT Pike Guide.

AVT Prosilica Gig E

A detailed guide for configuring and starting the stereo pair of Prosilica GC1380CH cameras can be found in the Care-O-Bot AVT Prosilica Guide.

Swissranger

Instructions for the usage of the Swissranger 3000 or 4000 sensor mounted on the Care-O-Bot can be found at Care-O-Bot Swissranger Guide.

Kinect

Instructions for the usage of the Microsoft Kinect sensor mounted on the Care-O-Bot can be found at Care-O-Bot Kinect Guide.