[Java-player-users] =?ISO-8859-1?Q?VFH?=

[Steffen J. <Ste...@gm...>]

Hi,

Problem 1:

I'm using the vfh driver with the PositionInterface. How do I determine when
the robot has reached its goal?

I've already tried to use getXSpeed and getYSpeed of the PositionInterface
and to do busy waiting until the robot stops. However, this doesn't work
satisfactorily, because it needs a very long delay (around one second)
before I can use the speed information without taking the risk that it is
not updated. Furthermore, busy waiting blocks my system unnecessarily.  


Problem 2:

My player config file defines two position devices:

driver
(
  name "vfh"
  provides ["position:3"]
  requires ["position:0" "laser:0"]
  
   max_speed 0.15
   max_turnrate 40
   safety_dist 0.10
   distance_epsilon 0.2
   angle_epsilon 360
   free_space_cutoff 100000000.0
)

driver
(
  name "stage"
  provides ["position:0" "laser:0"] 
  samples 181
  model "robot"
)

In order to get access to the position device at index 0 I simply do: 
ppd     = playerClient.requestInterfacePosition(0, 'a');

To get access to vfh which runs at index 3, however, it does not suffice to
request the PositionInterface at index 3, but I have to do the request three
times. The first call returns position:1 (which does not exist), the second
returns position:2 and finally the third call returns the desired
PositionInterface for vfh. This is independend of what indices I speficy in
the request method.
 
vfh     = playerClient.requestInterfacePosition(3, 'a'); 
vfh     = playerClient.requestInterfacePosition(3, 'a');
vfh     = playerClient.requestInterfacePosition(3, 'a');

Is it a bug or do I do something wrong?

Many thanks,
Steffen.

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