image_sonar_description

Image Sonar Notes and Description

The uuv_simulator includes the gazebo_ros_image_sonar.cpp sensor plugin to generate synthetic forward looking sonar observations.

These notes are an attempt to describe both the plugin interface as well as the methods used in the implementation.

Theory of Operation

ROS Interface

Published Topics

The topic names can be described in the plugin SDF. For this example, we have the following SDF configuration

	  <!-- This name is prepended to ROS topics -->
	  <cameraName>blueview_p900</cameraName>
	  <!-- ROS publication topics --> 
	  <imageTopicName>image_raw</imageTopicName>
	  <cameraInfoTopicName>image_raw/camera_info</cameraInfoTopicName>
	  <pointCloudTopicName>point_cloud</pointCloudTopicName>
	  <depthImageTopicName>image_depth</depthImageTopicName>
	  <depthImageCameraInfoTopicName>image_depth/camera_info</depthImageCameraInfoTopicName>

Message Type	Default or Typical Topic	Description
sensor_msgs::PointCloud2	/blueview_p900/point_cloud
------------	------------------------	----------
sensor_msgs::Image	/blueview_p900/image_depth
sensor_msgs::Image	/blueview_p900/image_depth_normals
sensor_msgs::Image	/blueview_p900/image_depth_multibeam
sensor_msgs::Image	/blueview_p900/image_depth_normals
sensor_msgs::Image	/blueview_p900/image_depth_raw_sonar
sensor_msgs::Image	/blueview_p900/image_depth_sonar
sensor_msgs::CameraInfo	/blueview_p900/image_depth/camera_info
-----------------	----------------------	---
sensor_msgs::Image	/blueview_p900/image_raw
sensor_msgs::CameraInfo	/blueview_p900/image_raw/camera_info
sensor_msgs::CompressedImage	/blueview_p900/image_raw/compressed
sensor_msgs::CompressedImage	/blueview_p900/image_raw/compressedDepth
theora_image_transport::Packet	/blueview_p900/image_raw/theora

Implementation Description

The base of the implementation is the DepthCamera implementation in Gazebo, and the model for the plugin is the DepthCameraPlugin.

For the DepthCameraPlugin we see this implmentation pattern:

• DepthCamera (Inherits from Camera): API
  • DepthCameraSensor: (Inherits from CameraSensor): Source (DepthCameraSensor.hh, DepthCameraSensorPrivate.hh and DepthCameraSensor.cc), [API](API
    • DepthCameraPlugin (Inherits from SensorPlugin): Source ( DepthCameraPlugin.cc ), API

For the Image Sonar, the DepthCameraPluign is replaced with the image sonar plugin.