Turtlebot4 SLAM do not work

PierreSteve1 commented 3 weeks ago

Robot Model

Turtlebot4 Standard

ROS distro

Galactic

Networking Configuration

Simple Discovery

OS

Ubuntu 20.04

Built from source or installed?

Installed

Package version

Debian package

Type of issue

Navigation (SLAM, Nav2 etc.)

Expected behaviour

I want to be able to correctly launch the synchronous, asynchronous and Rviz slam graphical interface

Actual behaviour

Hello, I am currently working on turtlebot4 standard. I am in the turtlebot4 common part of the turtlebot4 user manual. As mentioned in the guide, I started by installing the individual packages and launch files. You can see this in my screenshots screen. Once everything is installed, when I now enter this command on my Linux terminal: ros2 launch turtlebot4_navigation nav_bringup.launch.py slam:=sync , I receive error messages that I highlighted in white finally from you show what it is. The command does not launch the GUI. Also the other command: ros2 launch turtlebot4_navigation nav_bringup.launch.py slam:=async does not work too. That's not all, I I then tried to launch rviz with the command: ros2 launch turtlebot4_viz view_robot.launch.py, but I cannot view the map. I just see a graphical interface without a map when launching rviz. Can you help me please would you like to resolve this?

Error messages

Could not find a connection beetween Odom and base_link.Because they are not part or the same tree.Tf has two or more unconnected trees.
rplidar_link error.

To Reproduce

Installation

GALACTIC HUMBLE Debian package

Individual packages can be installed through apt:

sudo apt update sudo apt install ros-galactic-turtlebot4-description \ ros-galactic-turtlebot4-msgs \ ros-galactic-turtlebot4-navigation \ ros-galactic-turtlebot4-node

Navigation

The turtlebot4_navigation packages contains launch and configuration files for using SLAM and navigation on the TurtleBot 4. It also contains the TurtleBot 4 Navigator Python node.

GALACTIC HUMBLE Launch files:

Nav Bringup: Launches navigation. Allows for launch configurations to use SLAM, Nav2, and localization. SLAM Sync: Launches slam_toolbox with online synchronous mapping. Recommended for use on a PC. SLAM Async: Launches slam_toolbox with online asynchronous mapping. Recommended for use on the Raspberry Pi 4. Running synchronous SLAM:

ros2 launch turtlebot4_navigation nav_bringup.launch.py slam:=sync Running asynchronous SLAM with Nav2:

ros2 launch turtlebot4_navigation nav_bringup.launch.py slam:=async Running Nav2 with localization and existing map:

ros2 launch turtlebot4_navigation nav_bringup.launch

Other notes

No response

smatarCPR commented 2 weeks ago

Hello @PierreSteve1 , Thank you for reaching out on the Turtlebot 4 Github page.

Based on the the terminal outputs provided, it seems that the underlying issue is most likely a breakdown of communication between the Raspberry Pi, Create3 and your computer or a time sync issue.

Let's tackle the communication issues first. On your computer, can you see all topics from the Turtlebot 4 and Create3 (for example, we can see the rplidar exists which suggests the Raspberry Pi is communicating with your computer fine, but see if you can see and echo topics such as battery and wheel status). Is the complete list of topics that appear when ssh'ed to the Turtlebot 4 matched by the list of topics available on your offboard computer?

Next let's see how communication is between the Create3 and Raspberry Pi. First would it be possible to provide a copy of the latest Create3 logs (https://iroboteducation.github.io/create3_docs/webserver/logs/)? From those we'll see if the Create3 is connected to the wireless network. Do the ROS 2 domain settings in the Create3 match the ones being used by the Turtlebot 4 and your computer?

Should the above two checks pass, we'll begin looking into any potential time sync issues.

Lastly, I want to clear up some potential misconceptions, when launching the navigation stack ros2 launch turtlebot4_navigation nav_bringup.launch.py slam:=sync no GUI will be launched be default. After launching this command, in a separate terminal you can launch RVIZ (ros2 launch turtlebot4_viz view_robot.launch.py).

Let me know the results of these checks. Looking forward to hearing from you soon. Best Regards, Saif

PierreSteve1 commented 2 weeks ago

hello Saif, Regarding the list of topics, the command ros2 topic list executed on PC returns the following topics:

/battery_state
/cliff_intensity
/cmd_audio
/cmd_lightring
/cmd_vel
/color/preview/camera_info
/color/preview/image
/diagnostics
/diagnostics_agg
/diagnostics_toplevel_state
/dock
/hazard_detection
/hmi/buttons
/hmi/display
/hmi/display/message
/hmi/led
/imu
/interface_buttons
/ip
/ir_intensity
/ir_opcode
/joint_states
/joy
/joy/set_feedback
/kidnap_status
/mobility_monitor/transition_event
/mouse
/odom
/parameter_events
/robot_description
/robot_state/transition_event
/rosout
/scan
/slip_status
/static_transform/transition_event
/stereo/camera_info
/stereo/depth
/stop_status
/tf
/tf_static
/wheel_status
/wheel_ticks
/wheel_vels

which is exactly the same as in the terminal when ssh'ed to the RPi. The command ros2 topic echo /topic_name seems to work fine for all topics, but there is a delay of about 3 seconds before receiving anything on the terminal.

Here you can fine the latest Create3 logs. Please, note that the date given in the logs Jun 28 doesn't correspond to today's date, which is weird.

The ROS_DOMAIN_ID is the same for Create3, Turtlebot4 and the PC.

PierreSteve1 commented 1 week ago

I would like to add this remark regarding the connections between the frames. I used this command ros2 run tf2_tools view_frames to view the tree, which shows two disconnected trees. This is visualised in the following file.pdf: frames1-1 This shows that there is a connection between 'odom' and 'map' but they are isolated from the rest of the tree.

smatarCPR commented 6 days ago

Hello @PierreSteve1 , Thank you for sending the requested details and apologies for the late reply on this.

In terms of what we could find:

You mentioned that the Create3 topics (/odom) was seen on your computer, were you able to echo the topic on your computer (not while SSH'ed into the Pi)?
From the logs provided, it appears that the Create3 is not connected to Wi-Fi. If it was it would be able to time sync. In the logs we can see that the Create3 attempts to sync with an NTP server at 10.0.0.1, but it never appears to connect. This raises two questions:
Is the Create3 connected to a wi-fi network which has access to internet? You should be able to view an IP address in the connect tab in the webserver (https://iroboteducation.github.io/create3_docs/webserver/connect/)
The second question, have you made any changes to the ntp.conf for the Create3? The address 10.0.0.1 is not a standard NTP server address that we set as standard. We do not have a record of that address which leads us to suspect that a change has been made to ntp.conf for the Create3 updating it to use that address.

Let me know the results of these checks. Looking forward to hearing from you soon. Best Regards, Saif

turtlebot / turtlebot4