Hi, all, I am experimenting the navigation stack on our self-made omni robot. A tilt laser is installed and its separate testing is ok, i.e., the result of laser_filter and laser_snapshotter all look fine in rviz. Then I followed the setting under pr2_2dnav package, and try to run the whole navigation stack. I keep getting such warning info: ...... [ WARN] [1287143693.077180348]: The /ground_object_cloud observation buffer has not been updated for 37.21 seconds, and it should be updated every 0.20 seconds. [ WARN] [1287143693.177130903]: The /ground_object_cloud observation buffer has not been updated for 37.31 seconds, and it should be updated every 0.20 seconds. [ WARN] [1287143693.277171334]: The /ground_object_cloud observation buffer has not been updated for 37.41 seconds, and it should be updated every 0.20 seconds. [ WARN] [1287143693.377600991]: The /ground_object_cloud observation buffer has not been updated for 37.51 seconds, and it should be updated every 0.20 seconds. [ WARN] [1287143693.477116087]: The /ground_object_cloud observation buffer has not been updated for 37.61 seconds, and it should be updated every 0.20 seconds. [ WARN] [1287143693.495417506]: The /ground_object_cloud observation buffer has not been updated for 42.22 seconds, and it should be updated every 0.20 seconds. ...... the above /ground_object_cloud observation is included in the following costmap_common_params.yaml file: -------------------------- map_type: voxel origin_z: 0.0 z_resolution: 0.1 z_voxels: 16 obstacle_range: 2.5 raytrace_range: 3.0 robot_radius: 0.25 inflation_radius: 0.3 inscribed_radius: 0.25 circumscribed_radius: 0.3 observation_sources: base_scan_filtered base_laser_scan tilt_scan ground_object_cloud base_scan_filtered: {sensor_frame: baselaser_link, topic: /base_laser/scan_filtered, data_type: PointCloud, expected_update_rate: 0.2, observation_persistence: 0.0, marking: true, clearing: false, min_obstacle_height: 0.08, max_obstacle_height: 2.0} base_laser_scan: {sensor_frame: baselaser_link, data_type: LaserScan, topic: /base_laser/scan, marking: true, clearing: true} tilt_scan: {sensor_frame: laser_tilt_mount_link, topic: /tilt_laser/scan, data_type: LaserScan, expected_update_rate: 0.2, observation_persistence: 0.2, marking: false, clearing: true, min_obstacle_height: -20.00, max_obstacle_height: 40.0} ground_object_cloud: {sensor_frame: laser_tilt_mount_link, topic: /ground_object_cloud, data_type: PointCloud, expected_update_rate: 0.2, observation_persistence: 4.6, marking: true, clearing: false, min_obstacle_height: -0.10, max_obstacle_height: 2.0} and the topic: /ground_object_cloud is supposed to be generated by the sac_inc_ground_removal_node, as included in the launch file ground_plance.xml: ----------------------------- The weired thing is, for the above node, the input tilt_scan_cloud is confirmed existing, yet the output ground_object_cloud never generate, as observed in rviz and by the command line rostopic echo /ground_object_cloud. I am suspecting there is something wrong with the above process. I tried add two lines in the source file sac_inc_ground_removal_standalone.cpp, to suit for my case where base_link is used as alternative for robot_footprint_frame, yet no effect: node_.getParam ("robot_footprint_frame", robot_footprint_frame_); node_.getParam ("laser_tilt_mount_frame", laser_tilt_mount_frame_); any hints? thanks xiaojun -- View this message in context: http://ros-users.122217.n3.nabble.com/Navigation-stack-issue-about-ground-plane-detection-tp1707477p1707477.html Sent from the ROS-Users mailing list archive at Nabble.com.