ground_plane_estimation

Ground Plane

This package estimates the ground plane using depth images.

It can also be used with a fixed ground plane which is just rotated according to the ptu tilt angle. In this case the optimal ground plane is assumed and represented by the normal vector [0,-1,0] and the distance of 1.7 (Distance of the origin of the camera coordinated system to the plane in meters). These values can be changed in the config/fixed_gp.yaml file. As you can see this assumes to be used with the head_xtion and is therefore exclusive to the robot but it also prevents failurs due to wrongly estimated planes in cases where the camera can't see the ground. All this was necessary because the camera on the head of the robot is rather high and therefore has a high risk of not seeing the actual ground plane. At the current state of development it is advised to use the fixed plane set-up when running it on the robot.

Run

Parameters for estimation:

• load_params_from_file default = true: false tries to read parameters from datacentre, true reads parameters from YAML file specified by param_file
• param_file default = $(find ground_plane_estimation)/config/estimated_gp.yaml: The config file containing all the essential parameters. Only used if load_params_from_file == true.
• machine default = localhost: Determines on which machine this node should run.
• user default = "": The user used for the ssh connection if machine is not localhost.
• queue_size default = 5: The synchronisation queue size
• config_file default = "": The global config file. Can be found in ground_plane_estimation/config
• camera_namespace default = /head_xtion: The camera namespace.
• depth_image default = /depth/image_rect: camera_namespace + depth_image = depth image topic
• camera_info_rgb default = /rgb/camera_info: camera_namespace + camera_info_rgb = rgb camera info topic
• ground_plane default = /ground_plane: The estimated ground plane

Parameters for the fixed ground plane:

• load_params_from_file default = true: false tries to read parameters from datacentre, true reads parameters from YAML file specified by param_file
• param_file default = $(find ground_plane_estimation)/config/fixed_gp.yaml: The config file containing all the essential parameters. Only used if load_params_from_file == true.
• machine default = localhost: Determines on which machine this node should run.
• user default = "": The user used for the ssh connection if machine is not localhost.
• ptu_state default = /ptu/state: The current angles of the ptu
• ground_plane default = /ground_plane: The rotated ground plane

rosrun:

rosrun ground_plane_estimation ground_plane_estimated [_parameter_name:=value]

or

rosrun ground_plane_estimation ground_plane_fixed [_parameter_name:=value]

roslaunch:

roslaunch ground_plane_estimation ground_plane_estimated.launch [parameter_name:=value]

or

roslaunch ground_plane_estimation ground_plane_fixed.launch [parameter_name:=value]