How to navigate to unknown space in costmap?
Hello all,
I've followed the tutorial here http://www.ros.org/wiki/navigation/Tutorials/RobotSetup and also checked the website for similar questions but I am still quite confused and unable to produce the result I need.
I'm hooking up GMapping to the Costmap by setting static_map: true for global_costmap_params.yaml and static_map: falase for local_cost_map_params. However I wish to allow the robot, Pionneer3-AT to auto navigate itself in that environment. I thought of pointing the 2D Nav Goal to the unknown space from local_costmap but I've received errors and there's no reaction from the robot whatsoever.
Error from Costmap launch
[ERROR] [1371710574.377069274]: Client [/rostopic_25335_1371710566077] wants topic /move_base/local_costmap/unknown_space to have datatype/md5sum [geometry_msgs/PoseStamped/d3812c3cbc69362b77dc0b19b345f8f5], but our version has [nav_msgs/GridCells/b9e4f5df6d28e272ebde00a3994830f5]. Dropping connection.
Error from RVIZ
[ERROR] [1371710524.998325539]: md5sum mismatch making local subscription to topic /move_base/local_costmap/unknown_space. [ERROR] [1371710524.998429812]: Subscriber expects type nav_msgs/GridCells, md5sum b9e4f5df6d28e272ebde00a3994830f5 [ERROR] [1371710524.998484870]: Publisher provides type geometry_msgs/PoseStamped, md5sum d3812c3cbc69362b77dc0b19b345f8f5
rostopic echo /move_base/local_costmap/unknown_space would also most of the time not return anything.
I also applied unknown_cost_value: 255 and track_unknown_space: true to the costmap_common_params
It'll be great to get some help to achieve autonavigation in an unknown environment.
** EDIT 1 The errors were eliminated by setting static_map: false for global_costmap. However, there doesn't seem to be any path planning occuring. No errors were found in rxgraph and roswtf too.
** EDIT 2 The global_costmap_params.yaml has settings of static_map: false and rolling_window:true.
I've created a simple publisher and subscriber to subscribe to nav_msgs/GridCells on topic move_base/local_costmap/unknown_space and publish geometry_msgs/PoseStamped on topic /move_base_simple/goal. Since there are a bunch of coordinates of unknown space, a random coordinate is chosen.
The basic ROS tutorial for writing a subscriber/publisher should be referred to as an example.