Hi Maxim,

On Thu, May 2, 2013 at 12:36 PM, Maxim Vochten <vochtenmaxim [..] ...>wrote:

> Hi all,
>
>
> In my application I am using the ROS driver package 'ardrone_autonomy'
> together with Orocos/iTaSC for controlling the AR.Drone quadrotor robot
> wireless.
>
> I would like to report a disconnection issue that occurs during the
> execution of my program. This disconnection between the off board
> computer and the quadrotor lasts for about 1 second and only happens
> once during the entire lifetime of the program. There is no indication
> of any error.
>
> The problem was traced down to the following initialization of a
> KDL::Frame:
>
> KDL::Frame frame.p = KDL::Vector(0,0, (double) 1.2);
>
> causes the disconnection, but:
>
> KDL::Frame frame.p = KDL::Vector(0,0, (float) 1.2);
>
> solved the issue completely for me.
>
> The initialized frame undergoes a whole series of calculations, until
> ultimately it is transformed in a ROS message type
> 'geometry_msgs::Twist' which is sent to the quadrotor. The disconnection
> only occurs the first time this message is sent.
>
> This issue could possibly indicate an error in the KDL typekit.
>

Unlikely. The C++ part of KDL is independent of the typekit.

It probably indicates a bug in your setup, for example using old/outdated
binaries or a division by zero/use of nan somewhere.

You should try to run your deployer with valgrind to see if it reports any
'uninitialized values' or other invalid reads.

Peter