Unit 4 topic quiz

[sunnypinkpro]

I’ve tried to solve unit4 topic quiz.
I have a question below description?
Create a Subscriber that reads from the /kobuki/laser/scan topic. This is the topic where the laser publishes its data.

I got this contents that the kobuki robot send laser value to the subscriber node.
But, I have no idea how to run kobuki robot and how the robot can send laser value.
Where is the virtual kobuki robot??? and How can I test this quiz??

Could you let me know my understanding is correct or wrong???

[sunnypinkpro]

Please let me know the way to move below robot to test test topic_quiz??
I have no idea how can test the topic_quiz???

Thanks.

[rodrigo55]

Hi @sunnypinkpro, all of the simulations you see in the courses have everything you need to perform the quizes.

You can move a simulated mobile robot by publishing velocity messages to the velocity topic the simulated robot offers.

You can check that topic with rostopic list, and it usually is /cmd_vel.

In the node that you created the lidar subscriber, you can also create a publisher that moves the robot depending on the subscriber data.

[sunnypinkpro]

Hi rodrigo.

I think you got me wrong.
I don’t know basically how to launch the simulation Robot on the browser.
Could I get sample code to move it???

I tried to test example2.1 in our basic class.But the package and launch file don’t exist.
roslaunch turtlebot_teleop keyboard_teleop.launch

So, I have no idea how to run the simulation on the browser window.
That simulation is not “rviz” and “gazebo”.

thanks.

[bayodesegun]

Do you understand the previous units? Have you even gone through them?

To move the robot, you need to create a publisher, and then publish “move” commands to the /cmd_vel topic.

To “see” the laser messages, create a subscriber and specify a callback function where the subscriber will send these messages. You can access the messages in the subscriber callback.

The robot? You will use the robot in the simulation.

[sunnypinkpro]

Thank you for reply.

I solved this issue.
It came out of my environment issue.