No map received in Rviz using Turtlebot3 in Gazebo- Reopen issue

[nagarjunvinukonda]

Hi, I am facing the same problem. can this issue be reopened?

I am using ROS melodic 18.0.4.

I am trying to gmap the turtlebot3_world.launch file using the command: roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping But, I am having trouble with No map received:

As @routiful told above I dont find any mistake in my terminal while I launch gmapping, THis is the following output in my terminal :

` nagarjunv@nagarjunv-Inspiron-7580:~/hk_ws$ roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping ... logging to /home/nagarjunv/.ros/log/891ec6d0-b42e-11eb-90d9-3c6aa7417fe4/roslaunch-nagarjunv-Inspiron-7580-12859.log Checking log directory for disk usage. This may take a while. Press Ctrl-C to interrupt Done checking log file disk usage. Usage is <1GB.

xacro: in-order processing became default in ROS Melodic. You can drop the option. started roslaunch server http://nagarjunv-Inspiron-7580:38227/

SUMMARY

PARAMETERS

• /robot_description: <?xml version="1....
• /robot_state_publisher/publish_frequency: 50.0
• /robot_state_publisher/tf_prefix:
• /rosdistro: melodic
• /rosversion: 1.14.10
• /turtlebot3_slam_gmapping/angularUpdate: 0.2
• /turtlebot3_slam_gmapping/astep: 0.05
• /turtlebot3_slam_gmapping/base_frame: base_footprint
• /turtlebot3_slam_gmapping/delta: 0.05
• /turtlebot3_slam_gmapping/iterations: 5
• /turtlebot3_slam_gmapping/kernelSize: 1
• /turtlebot3_slam_gmapping/lasamplerange: 0.005
• /turtlebot3_slam_gmapping/lasamplestep: 0.005
• /turtlebot3_slam_gmapping/linearUpdate: 1.0
• /turtlebot3_slam_gmapping/llsamplerange: 0.01
• /turtlebot3_slam_gmapping/llsamplestep: 0.01
• /turtlebot3_slam_gmapping/lsigma: 0.075
• /turtlebot3_slam_gmapping/lskip: 0
• /turtlebot3_slam_gmapping/lstep: 0.05
• /turtlebot3_slam_gmapping/map_frame: map
• /turtlebot3_slam_gmapping/map_update_interval: 2.0
• /turtlebot3_slam_gmapping/maxUrange: 3.0
• /turtlebot3_slam_gmapping/minimumScore: 50
• /turtlebot3_slam_gmapping/odom_frame: odom
• /turtlebot3_slam_gmapping/ogain: 3.0
• /turtlebot3_slam_gmapping/particles: 100
• /turtlebot3_slam_gmapping/resampleThreshold: 0.5
• /turtlebot3_slam_gmapping/sigma: 0.05
• /turtlebot3_slam_gmapping/srr: 0.1
• /turtlebot3_slam_gmapping/srt: 0.2
• /turtlebot3_slam_gmapping/str: 0.1
• /turtlebot3_slam_gmapping/stt: 0.2
• /turtlebot3_slam_gmapping/temporalUpdate: 0.5
• /turtlebot3_slam_gmapping/xmax: 10.0
• /turtlebot3_slam_gmapping/xmin: -10.0
• /turtlebot3_slam_gmapping/ymax: 10.0
• /turtlebot3_slam_gmapping/ymin: -10.0

NODES / robot_state_publisher (robot_state_publisher/robot_state_publisher) rviz (rviz/rviz) turtlebot3_slam_gmapping (gmapping/slam_gmapping)

ROS_MASTER_URI=http://localhost:11311

process[robot_state_publisher-1]: started with pid [12894] process[turtlebot3_slam_gmapping-2]: started with pid [12895] process[rviz-3]: started with pid [12896]

` The following are the images from Rviz:

I have downloaded Turtlebot Simulations and turtlebot3 packages from the following link:

https://github.com/ROBOTIS-GIT/turtlebot3_simulations https://github.com/ROBOTIS-GIT/turtlebot3

I have freshly downloaded the above packages and catkin_make. But still don't work while doing mapping.

The following is image of rqt_graph:

THe following is image of tf_tree:

Can anyone please let me know what exactly is the problem and how to solve it?

[ROBOTIS-Will]

@nagarjunvinukonda I just downloaded the latest source code and built and ran, but seems okay to me. Terminal 1

$ roslaunch turtlebot3_gazebo turtlebot3_world.launch

Terminal 2

$ roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping

Could you give us a specific steps to reproduce your issue?

[nagarjunvinukonda]

Hello ROBOTIS-Will,

Thanks for reaching out. Sorry for the late response. Yes, I have checked even with my peers, it's surprising for me why its happening for my system. Its not just for me but I have seen online this problem is happening for others too.

I have seen the ros topics, over there the laser data is not been subscribed by gmapping package even though gazebo is publishing. Hence, the map is not been received. I dont understand why it is not subscribing.

One of the solutions I found is to reinstall the ROS. Since even though I have installed the package couple of times it still doesn't give results.

I am thinking it might be because the gmapping package doesn't subscribe GPU laser scans. It only subscribes to normal rays.

[ROBOTIS-Will]

I don't see a /tf message in your node graph. Could you check if you have installed tf on your machine?

$ sudo apt install ros-melodic-tf