Help understanding the notation used on ar-drone tutorial

asked 2013-08-17 14:31:33 -0600

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Hi everyone, for the tutorial link:https://github.com/AutonomyLab/ardrone_autonomy#cameras</a">text, under

Sending Commands to AR-Drone

It shows three highlighted commands which are: ardrone/takeoff ardrone/land and ardrone/reset. These are topics so is the full commands actually: rostopic /ardrone/takeoff rostopic /ardrone/land androstopic /ardrone/reset ?

Also, to fly the drone after takeoff, would I do something like: rostopic cmd_vel -linear.x to move the drone backwards?

I am trying to understand how to read the commands listed, sorry that this is basic.

answered 2013-08-17 20:24:19 -0600

Alexandr Buyval
641 ●11 ●15 ●24

updated 2013-08-17 20:27:45 -0600

Hi,

If you want to send a message from terminal you should use the command like:

rostopic pub /ardrone/land std_msgs/Empty

For /cmd_vel you should use the command like:

rostopic pub /cmd_vel geometry_msgs/Twist  '{linear:  {x: 0.1, y: 0.0, z: 0.0}, angular: {x: 0.0,y: 0.0,z: 0.0}}'

Alex

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Comments

Brilliant! One thing that I would have not known from the tutorial is std_msgs/ Is this used to say 'I am going to send an empty message' ?

JP ( 2013-08-18 01:40:33 -0600 )edit

Yes, it is.

Alexandr Buyval ( 2013-08-18 20:47:59 -0600 )edit

thank you !

JP ( 2013-08-18 23:55:40 -0600 )edit

Just to check, for the section https://github.com/AutonomyLab/ardrone_autonomy#cameras am I correct to say the commands to get a stream of the front and bottom cameras are: $ rostopic pub ardrone/front/image_raw image_transport and $ rostopic pub ardrone/bottom/image_raw image_transport ?

JP ( 2013-08-19 06:01:53 -0600 )edit

Hi. Do you want to toggle camera?

Alexandr Buyval ( 2013-08-19 20:25:43 -0600 )edit

hi, nope I would like to display the front facing camera on my computer screen if possible.

JP ( 2013-08-19 23:58:23 -0600 )edit

You need to use image_view package. Like this "rosrun image_view image_view image:=/ardrone/image_raw"

Alexandr Buyval ( 2013-08-20 03:21:50 -0600 )edit

Perfect. Thank you Alexandr!

JP ( 2013-08-20 14:05:13 -0600 )edit

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