The telepresence node

This package takes a ROS image stream, and accepts a service that sends out a move_base goal at the location of the object that was 'clicked' through the given camera pixel.

The package includes two nodes:

1. image_filter

This node syncs the Image and the CameraInfo messages. This is sometimes needed if the network is slow.

It also undistorts fisheye lens images, if the undistort arg is set in the launch file.

2. telepresence

This node handles the geometric transformations needed to find the goal in the image.

It needs a nav_msgs/OccupancyGrid of the map and tf data of the camera. It also publishes the goal to tf.

If a depth cam is available, it can also subscribe to a sensor_msgs/Pointcloud2 point_map topic to find obstacles.

When the node finds and obstacle, it steps back a configurable distance so the goal doesn't make the robot stuck in a costmap.

A maximum distance is set that is hit if there is no closer obstacle found.

The search granuality, and the robot radius also have to be set.

An rviz visualization of the ray cast can also be enabled.

The below picture contains additional information about the communication of the nodes.

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Browser interface

There is also a browser interface implemented, that can be toggled in the launch file. It streams the image from the telepresence node that can be clicked to send a goal to a robot.

Important: internet connection os needed to load the rosjs libraries

It can send rotation commands on the cmd_vel topic.

It can also cancel the current move_base goal.

A screenshot is shown below of the browser interface next to rviz.