Ask Your Question

What topic should I subscribe to know when the drone is in "hover state"?

asked 2015-01-24 09:54:52 -0500

Michael Panayiotou gravatar image

Basically, I'm trying to write a piece of code that waits for the drone to enter hover state and then take a picture from the drone's camera. I've manage to take the picture (by subscribing to ardrone/image_raw topic). I only need to know what topic should I subscribe so I can set up a subscriber and using a callback function I will be able to take pictures from the drone only when it is in hovering state.

Thank you in advance.

p.s: I use tum_ardrone and ardrone_autonomy to communicate with the drone. I've also created a package that uses some opencv code to take the picture from the drone's camera.

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted

answered 2015-03-08 14:33:10 -0500

Michael Panayiotou gravatar image

- ardrone/navdata topic.

Information received from the drone will be published to the ardrone/navdata topic. The message type is ardrone_autonomy::Navdata and contains the following information:

  • header: ROS message header
  • batteryPercent: The remaining charge of the drone's battery (%)
  • state: The Drone's current state: * 0: Unknown * 1: Inited * 2: Landed * 3,7: Flying * 4: Hovering * 5: Test (?) * 6: Taking off * 8: Landing * 9: Looping (?)
  • rotX: Left/right tilt in degrees (rotation about the X axis)
  • rotY: Forward/backward tilt in degrees (rotation about the Y axis)
  • rotZ: Orientation in degrees (rotation about the Z axis)
  • magX, magY, magZ: Magnetometer readings (AR-Drone 2.0 Only) (TBA: Convention)
  • pressure: Pressure sensed by Drone's barometer (AR-Drone 2.0 Only) (Pa)
  • temp : Temperature sensed by Drone's sensor (AR-Drone 2.0 Only) (TBA: Unit)
  • wind_speed: Estimated wind speed (AR-Drone 2.0 Only) (TBA: Unit)
  • wind_angle: Estimated wind angle (AR-Drone 2.0 Only) (TBA: Unit)
  • wind_comp_angle: Estimated wind angle compensation (AR-Drone 2.0 Only) (TBA: Unit)
  • altd: Estimated altitude (mm)
  • motor1..4: Motor PWM values
  • vx, vy, vz: Linear velocity (mm/s) [TBA: Convention]
  • ax, ay, az: Linear acceleration (g) [TBA: Convention]
  • tm: Timestamp of the data returned by the Drone returned as number of micro-seconds passed since Drone's boot-up.
edit flag offensive delete link more


Hello what means TBA unit

yasser gravatar image yasser  ( 2016-02-10 08:18:38 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower


Asked: 2015-01-24 09:54:52 -0500

Seen: 386 times

Last updated: Mar 08 '15