Mode change to LOITER failed: requires position with only PX4flow

ArduCopter Copter 4.3
21

FlowHold mode was never really completed and never worked very well for me in testing. Be careful when trying to use it.

The sonar on the PX4flow is not very good, and not recommended for use from what I remember. Try using something like a TFmini which is pretty cheap and much better overall.

22

Hey @vosair,

Thank you for your advice.

So now I will purchase the TFMini-S Micro LiDAR Distance Sensor and I hope this solve my problem to takenoff with loiter with px4flow only.

23

Hello,

Here I have attached a .bin file where I have tried FlowHold mode. And as written in the wiki it gives the wobbling result and also the same told by you. But I didnā€™t observe any kind of drift in a specific direction.

So do I consider that PX4flow is well calibrated with FLOW_FXSCALER and FLOW_FYSCALER parameters and after adding TFMini-S Micro LiDAR, wobbling will stop? And It will work with Loiter.

24

Hey @vosair and @JDANILOM ,

I have successfully installed a Benewake TFmini downward direction and it works as per the wiki of the rangefinder.

But still, when I try to take off in loiter mode as per wiki, I am facing the same error ā€œMode change to LOITER failed: requires positionā€.

I have attached the
RFLT_3 1-1-1980 5-30-00 AM.bin (964 KB)
parameters file and .bin file here.
RFLT.param (17.1 KB)

I will be glad if anyone could comment on this.

25

Hey @Yuri_Rage and @andyp1per

Would you like to give your comments on this problem?

Because I followed all the steps of the wiki but still I am facing the error ā€œMode change to LOITER failed: requires positionā€

So I will be glad if anyone could help me with this problem.

26

Okay now it works but it canā€™t take off in Loiter mode as per Optical Flow Sensor Testing and Setup ā€” Copter documentation

image
image996Ɨ683 75.1 KB

In my case, I have to first take off in AltHold mode and after 1 m I m able to change to loiter mode with PX4flow. I would like to request the ardupilot wiki editors kindly correct it so that in future no one confuse there.

if anything else please correct me.

2 Likes
27

Hi Yash. I am having the same problem. When I activate loiter mode at 1m height, quadcopter goes up and does not hold position. Were you able to get quad to loiter in one position? My quad starts to drift itā€™s position as soon as I put it in Loiter mode.

28

Hey @rmeraj1,

I would like to suggest first calibrate your flow sensor as per documentation dont miss single step. And then before to do second flight test check flow sensor performance in flowhold mode instead of directly try in loiter mode.

To check performance in flowhold mode first take of in altitude mode with rangfinder on vehicle and engage to flowhold mode and check performance of vehicle.
For safety be always ready to switch back in altitude hold mode in case of quad is going out of control in flowhold mode.

I hope after this you will achieve good position hold.