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Help Object Avoidance TF02


(Eduard cabanas Gili) #1

HI,

I installed TF02 to my pixhawk cube and works perfect, the sonar value is correct and the proximity window shows correctly how the objects come to the rover.

I followed the manual
http://ardupilot.org/copter/docs/copter-object-avoidance.html#copter-object-avoidance
but the rover did not avoid any object from the path (auto or guided)

If anyone could help me, I really appreciate

Log link: https://www.dropbox.com/s/98aueznz6cx7hdr/00000084.BIN?dl=0

Thank’s

Eduard


(rmackay9) #2

Hi Eduard,

This is the object avoidance wiki page for Rover.

In Auto and Guided modes the “Dodge” method will be used and I’m afraid it doesn’t actually work that well in practice because it’s a very simple algorithm. It was designed for the Sparkfun AVC so it can perhaps be made to work so the vehicle steers around barrels (or other similar obstacle) while travelling at a specific speed but it’s not a general purpose solution.

In any case the parameters that control this behaviour are on the rover-object-avoidance wiki page. The key ones to adjust are RNGFND_TRIGGR_CM, RNGFND_TURN_ANGL (which is not really a turn angle) and RNGFND_TURN_TIME.

We are working on object avoidance though, the ROS based solution described here is the most impressive but it is still a work-in-progress.


(Eduard cabanas Gili) #3

Hi @rmackay9

Thank you for your answer, today I setup the vehicle following the wiki guideline.

The rover moved when see an obstacle, but the problem was the square was not enough big and waving appears passing the waypoints. And sometimes the rover did not recognize the obstacle and hit me.

Is this configuration correct?

RNGFND_TRIGGR_CM: 100
RNGFND_TURN_ANGL: 45
RNGFND_TURN_TIME: 1s
RNGFND_DEBOUNCE: 1
RNGFND_MAX_CM: 1200
RNGFND_MIN_CM: 5

AVOID_DIST_MAX:2
AVOID_MARGIN: 1
AVOID_ENABLE: 7

Now I received an RTK here+ and maybe improves the waves, no?

Thank’s

Eduard


(rmackay9) #4

@ecabanas,

Those parameters generally look OK although perhaps RNGFND_TURN_ANGL is too low.

I’ll need to see a log I think to understand the cause of the wave/wobble. Really though, the dodge method doesn’t work too well… at the risk of appearing to “pass the buck”, I’ve spent a couple of days in the past few months trying to make it work (mostly in the simulator) and I’ve come to the conclusion that it’s not really going to work well… so I’m afraid I can’t spend a lot of time trying to help make it work because I think a better use of my time is to try and replace it with something better.