Collision prevention

[gauravshukla914]

Hi, We are trying to test the collision prevention feature on our Voxl flight deck enabled drone. We've set the PX4 parameters as mentioned in the documentation of collision prevention. Its working fine when I set the cp_dist to 1.5 meters as told. It works well and the drone stops.

However, if at all I keep some other value less than 1.5 m, for example, 1 meter or 1.2 meter, or 0.8 meters, it doesn't stop for the obstacle and I just hear "collision warning" from QgroundControl station. So is 1.5 meter a standard value and we can't use any number less than that?

[modaltb]

Hi @gauravshukla914 ,

I didn't know of any limitation, our factory test uses 1.5 --> https://gitlab.com/voxl-public/flight-core-px4/px4-parameters/-/blob/master/helpers/collision_prevention.params#L7

We'll need to check out what is introducing the limit.

[gauravshukla914]

Thanks for your reply @modaltb . That'd be great. I'll look forward to your response.

[kiprock]

gauravshukla914 Just curious, are you trying https://github.com/PX4/PX4-Avoidance or something else for collision prevention?

[gauravshukla914]

@modaltb any idea on this?

[gauravshukla914]

@kiprock No. I'm following the modalai collison prevention documentation.

[Chad Sweet]

I don't think we have tried other values. You can see where PX4 computes min_distance here, that might help

[modaltb]

The only lower bound I've seen is 20cm here:
https://gitlab.com/voxl-public/modal-pipe-architecture/voxl-vision-px4/-/blob/master/src/voa_manager.c#L165

So I'm still puzzled.

If you debug stereo, what kind of data are you seeing? https://docs.modalai.com/voxl-vision-px4-collision-prevention/#debug-tools