When I exported my layout it saved in the Downloads folder on my laptop. I was expecting it to save somewhere within the simulation. Is this correct?
Also following on from my logging out oversight I was caught out by the following.
I logged out of the simulation but went here to comment. I was asked to log in and did so. When I had commented I could not see a method to log off here so I went back to simulation which seemed to indicate I was logged off. I realise now I should have logged on and then logged out again to clear both elements of my session.
That is why I did not run a session yesterday.
You shouldn’t have to logout for your workspace usage session to reset. That should work irrespective of whether you’re logged in or not.
Yes, this is correct. You can later import the layout back via the import option from your file system.
I believe I have set up everything correctly, re-imported my layout but although the wheels appear to turn (and stop when re-set) my robot is not moving. I can not work out what is wrong - i Have cleared and re-started to make sure I have followed all steps cleanly - there is one error message but I do not think that should be fatal. I have left all my shells open if you are able to review I would be very grateful.
As I am almost out of time today I will retry later tomorrow to see if I can get movement using the ROS2 commands
Sure, let me check and get back
Your setup is fine. The robot is moving with gazebo as well as the ros2 commands. Make sure the cmd_vel topic is bridged from ros to gazebo if you’re trying to move the robot using ros2 commands. The gazebo commands should work fine as it is.
Also you can remove the two obstacles you had placed in front of the robot in the museum world, before you get your robot moving.
Thanks for your help. I have proceeded well today. I only got one minor difference from the expected results shown in the text. When I started before adding the third bridge you say I should get the error
Waiting for at least 1 matching subscription(s)…
Waiting for at least 1 matching subscription(s)…
Waiting for at least 1 matching subscription(s)…
but I got the following (repeating with an increasing count)
publishing #16: geometry_msgs.msg.Twist(linear=geometry_msgs.msg.Vector3(x=0.05, y=0.0, z=0.0), angular=geometry_msgs.msg.Vector3(x=0.0, y=0.0, z=0.0))
I do not know if this is important
Also in the next lesson when I run
gz topic -i -t /odom
I get
Publishers [Address, Message Type]:
tcp://169.254.8.1:41363, gz.msgs.Odometry
No subscribers on topic [/odom]
rather than the message you show. This might confuse a beginner. I realise the simulation is just running under a different IP and more info is being shown.
Glad to hear about your progress!
If you run the command in this section, since we haven’t bridged cmd_vel topic between ros and gazebo, you should see these messages being printed:
Waiting for at least 1 matching subscription(s)…
Waiting for at least 1 matching subscription(s)…
Waiting for at least 1 matching subscription(s)…
It could be that in your case you’ve already bridged cmd_vel from ros to gazebo.
Regarding the output of gz topic -i -t /odom, thanks for pointing out that the difference could be confusing. I’ve updated the section to point that out.
I have just completed chapter 6 and found the following variations from the stated expectations which may be confusing to less experienced readers
In 06/02 checking scan is alive I get the following rather than the three lines shown in the text.
root@localhost:~# ros2 topic list
/clicked_point
/cmd_vel
/initialpose
/joint_states
/move_base_simple/goal
/odom
/parameter_events
/robot_description
/rosout
/scan
/tf
/tf_static
in section 06/02 if you press Ctrl C to stop the listing and then open a new terminal you get
ros2 node info /perception
Unable to find node ‘/perception’
The perception node needs to be still running to get the node info
In section 06/04 I get a timestamp whenever I run perception e.g.
[INFO] [1786120567.108210081] [perception]: front = 7.35m
Thanks for pointing these out. I’ve updated the lesson content accordingly.
In 07/07 I get an extra parameter
ros2 param list /planner
start_type_description_service
stop_distance
use_sim_time
Starting from 07/07 I spent a long time working out why I could not get the expected results. As well as the commands shown for bring up I also need to restart the controller and planner ( and maybe others but I am out of time for today) It would help if this was clear in the text (or amend the “Bring up commands” subsection).
I also created a reset.sh file to make stopping and resetting easier. Feel free to use it if you think it would help others/
Thanks, I had missed to specify that the perception node had to be running before testing the planner node. I’ve added it as part of the bring up commands, and also specified it has to be running when testing the other nodes.
Regarding the script for resetting the robot, it’s definitely helpful but I’m leaving it up to the reader for now so they get familiar with the commands.
When I run ros2 param list after parameterising the elements I get a lot more then shown in the lesson
:-
/controller:
forward_speed
start_type_description_service
turn_speed
use_sim_time
/foxglove_bridge:
address
asset_uri_allowlist
best_effort_qos_topic_whitelist
capabilities
certfile
client_topic_whitelist
disable_load_message
ignore_unresponsive_param_nodes
include_hidden
keyfile
max_qos_depth
min_qos_depth
param_whitelist
port
qos_overrides./parameter_events.publisher.depth
qos_overrides./parameter_events.publisher.durability
qos_overrides./parameter_events.publisher.history
qos_overrides./parameter_events.publisher.reliability
send_buffer_limit
service_whitelist
start_type_description_service
tls
topic_whitelist
use_compression
use_sim_time
Wait for service timed out waiting for parameter services for node NodeName(name=‘foxglove_bridge_component_manager’, namespace=‘/’, full_name=‘/foxglove_bridge_component_manager’)
/perception:
start_type_description_service
use_sim_time
/planner:
start_type_description_service
stop_distance
use_sim_time
/robot_state_publisher:
frame_prefix
ignore_timestamp
publish_frequency
qos_overrides./joint_states.subscription.depth
qos_overrides./joint_states.subscription.history
qos_overrides./joint_states.subscription.reliability
qos_overrides./parameter_events.publisher.depth
qos_overrides./parameter_events.publisher.durability
qos_overrides./parameter_events.publisher.history
qos_overrides./parameter_events.publisher.reliability
qos_overrides./tf.publisher.depth
qos_overrides./tf.publisher.durability
qos_overrides./tf.publisher.history
qos_overrides./tf.publisher.reliability
qos_overrides./tf_static.publisher.depth
qos_overrides./tf_static.publisher.history
qos_overrides./tf_static.publisher.reliability
robot_description
start_type_description_service
use_sim_time
/ros_gz_bridge:
bridge_names
config_file
expand_gz_topic_names
lazy
override_frame_id
override_timestamps_with_wall_time
qos_overrides./cmd_vel.subscription.depth
qos_overrides./cmd_vel.subscription.history
qos_overrides./cmd_vel.subscription.reliability
qos_overrides./joint_states.publisher.deadline
qos_overrides./joint_states.publisher.depth
qos_overrides./joint_states.publisher.durability
qos_overrides./joint_states.publisher.history
qos_overrides./joint_states.publisher.liveliness
qos_overrides./joint_states.publisher.reliability
qos_overrides./odom.publisher.deadline
qos_overrides./odom.publisher.depth
qos_overrides./odom.publisher.durability
qos_overrides./odom.publisher.history
qos_overrides./odom.publisher.liveliness
qos_overrides./odom.publisher.reliability
qos_overrides./parameter_events.publisher.depth
qos_overrides./parameter_events.publisher.durability
qos_overrides./parameter_events.publisher.history
qos_overrides./parameter_events.publisher.reliability
qos_overrides./scan.publisher.deadline
qos_overrides./scan.publisher.depth
qos_overrides./scan.publisher.durability
qos_overrides./scan.publisher.history
qos_overrides./scan.publisher.liveliness
qos_overrides./scan.publisher.reliability
start_type_description_service
subscription_heartbeat
use_sim_time
root@localhost:~/ros2_ws#
Thanks for pointing this out as well. I’ve updated the content to just check the parameters for the nodes individually, or one might have to use grep to filter out specific nodes after ros2 param list.
I seem to have a glitch I can’t spot how to fix. I started the workspace OK and switched in to it, started running commands but now can’t see the usual marker to shrink it back so I can see the text to progress with the lesson. I have tried shrinking the screen but that only seems to shrink the text in each window.
If I refresh my Firefox window I can get back to the lesson but I am sure this is not the right way to do it. Once in the simulation mode I do not seem to have the bar at the top to go back to the lesson.
I am not sure if this may be a Firefox issue as I now get scroll bars even when in the text page and have to scroll to see all the scree, These scroll bars do not appear in the simulation. I have checked the firefox options and they are showing the screen should be at 100%. If I reduce that each of the windows in the simulation shrinks but I do not get the ability to shrink back to the text.
I am going to log off and see if I can find any bug reports on Firefox which might be helpful.
Any suggestions you have would be gratefully received.
I can find no Firefox issues and I have tried a number of other sites which all display as expected. I now get side and bottom scroll bars when logging on to the tutorial. It only seems to be affecting your site (and not this bug reporting page). I am on Firefox 153.0.4
The problem must have been at my end. I completely closed the firefox tab with the simulation, re-booted and opened a brand new firefox tab and all seems to be working now. I have no idea how I changed the display size.
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You can click anywhere on the workspace bar to minimize the workspace. Alternatively you can also pop out the workspace into a new tab. Let me know if you face any issues.
I have had to login this morning using google as trying to use my email produced the error
Captcha verification failed. Please try again.
but I have not been shown any captcha to complete
This means I have lost everything I have done to date (previously I was user threent