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hector_quadrotor-gazebo1.9 doesn't respond to command velocity

asked 2014-05-06 19:53:17 -0500

Robert gravatar image

Hi Everyone, I installed the hectorquadrotor from source (hydro and 1.9 gazebo) and launched the file “quadrotoremptyworld.launch”. Everything seems to be ok, emptyworld with one quadrotor, until I provided to the quadrotor a velocity command using “rostopic pub” and the quadrotor doesn’t move at all. I verified via “rqtgraph” that gazebo is connected to the right topic (/cmdvel) and also verified if the data is published on the topic. Everything seems to be normal and I don’t know what else I can check. Any idea about this problem? Thank you for any help with this issue

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answered 2014-05-07 02:06:00 -0500

Hi for me this command works:

rostopic pub /cmd_vel geometry_msgs/Twist '[0, 0, 1]' '[0, 0, 0]'

The problem might be that your quadcopter is not flying.

If the quadcopter is on the ground it needs a Twist with positive linear.z value. The program will print Engaging motors! As soon as you land on the ground the programm will print Shutting down motors! Which will mean you have to start it again.

Let me no if this does not solve your problem...

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Hi evilBiber, thanks a lot for your tip. it worked and quadrotor took off. But I observed after awhile the quadrotor get frozen (motionless) on the space. I checked the quadrotor' pose via "rostopic echo /groundtruth/state" and the pose values are the same after reaching certain altitude (~952m). Also, I provided 0 command velocity (rostopic pub /cmdvel geometry_msg/Twist '[0, 0, 0,]' '[0, 0, 0]') to the quad to land on the ground but the quad stayed motionless. Do you know how to land the quad on the ground?. Thanks a lot again

Robert gravatar imageRobert ( 2014-05-07 11:01:39 -0500 )edit

you have to use negative z values for going down.

evilBiber gravatar imageevilBiber ( 2014-05-08 03:59:47 -0500 )edit

Thanks alot again! your tip worked and quad landed

Robert gravatar imageRobert ( 2014-05-08 10:22:48 -0500 )edit

Thanks Robert! This helped me! :)

vinaykumar gravatar imagevinaykumar ( 2015-04-17 23:37:11 -0500 )edit
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Asked: 2014-05-06 19:53:17 -0500

Seen: 1,565 times

Last updated: Apr 17 '15