Mantis Q won't hold stationary position while hovering

[j76]

I recently got a Mantis Q (refurb) and it seems to work ok with the exception of the fact that it will.not hold a stable position during hover.
It will hold position for about 5 seconds and then start drifting around. At first it will start drifting around a foot to 2 feet in any direction, and if left on its own it will start drifting further. I've witnessed it drift upwards of 10ft horizontally and around 8ft vertically.

i've recalibrated the compass a few times all with the same result. (Successful calibration...yet drone still drifts around like a drunk following a gnat at a picnic)

since it's refurbished and there are no signs of life in Yuneec support, should I just go ahead and get a new GPS, compass, ultrasonic\optical flow board, and\or mainboard and swap them out one at a time and see if anything makes a difference?


is the source code available for download per chance? Perhaps there are settings in this that can be adjusted. Or maybe work on updating it to the latest version of PX4.

thanks

 

[DoomMeister]

I think you will find the individual parts will cost more than buying another refurb. With the symptoms you describe it actually sounds like a problem of overheating since the problem grows over time.

When this starts, try flying for a minute then bring it back and place in a hover. Is the condition better, worse, or the same?

Some use Q Ground Control with the Mantis. There is a little about that on the forum, but likely to be more about it doing a web search.

 

[j76]

I think you will find the individual parts will cost more than buying another refurb. With the symptoms you describe it actually sounds like a problem of overheating since the problem grows over time.

When this starts, try flying for a minute then bring it back and place in a hover. Is the condition better, worse, or the same?

Some use Q Ground Control with the Mantis. There is a little about that on the forum, but likely to be more about it doing a web search.

I will try your suggestion next time I can fly it and note the results.

How does one use QGC with the Mantis Q and it's controller?

I was also wondering does the ST16 or ST10 ground control units work with the Q or are they only restricted to the Typhoons?

 

[DoomMeister]

QGC cannot be used with the Mantis controller. You control it through a computer. Not a choice in my opinion unless you are doing automated missions.

The ST series controllers do not work with the Mantis series of aircraft. The ST’s use a 2.4GHz RC signal for aircraft and gimbal control and 5.8GHz WiFi signal for video feed and camera control.

The Mantis Q uses a 5.8GHz WiFi signal for all of its control.

 

[Vasir]

It could also depend on what you classify as hovering ground. I have issues when over grass around 4-5 feet and it was a bit windy. The over heating issue does make sense, however if thermal throttling kicks in, unless main functionalities are prioritized in drones RTOS you would see other issues as well. Retrieving logs I did not see any temp issues.
I also got the refurb to get my way into drone hobby, turned out that I became well in taking this thing apart for every issue which overtime means that things will start going bad just because I am plugging/unplugging wires. Yesterday it just crashed and I found out that the plug came out because of high frequency "shaking" in flight.

There is a youtube channel that explains hovering and why surfaces matter and what the drone sees and uses, GPS or its internal sensors on the bottom and when these sensors kick in.

 

[j76]

It could also depend on what you classify as hovering ground. I have issues when over grass around 4-5 feet and it was a bit windy. The over heating issue does make sense, however if thermal throttling kicks in, unless main functionalities are prioritized in drones RTOS you would see other issues as well. Retrieving logs I did not see any temp issues.
I also got the refurb to get my way into drone hobby, turned out that I became well in taking this thing apart for every issue which overtime means that things will start going bad just because I am plugging/unplugging wires. Yesterday it just crashed and I found out that the plug came out because of high frequency "shaking" in flight.

There is a youtube channel that explains hovering and why surfaces matter and what the drone sees and uses, GPS or its internal sensors on the bottom and when these sensors kick in.

You don't happen to have a link for that YouTube video\channel do you?

I haven't had much time lately to test things out. Wife is very ill, kids birthday, work, etc...

I'll try and test the surfaces theory out as well as height and time.

I have noted erratic hovering stability over asphalt (my driveway) as well as grass (my yard) as well as both where they meet. The flying height was the standard approximate 4ft takeoff height. It would hold position for about 5 seconds and then slowly start drifting in every direction. The drifting would get greater until it was about 6-8ft from its original position.

I'll see if I can test out a stationary hover at a height of around 20ft and see how it goes.

If it's overheating how would I fix that? It already has a fan...take it apart and remove the shield, reapply thermal paste and a small thin heatsink and put it back together?

 

[Vasir]

You don't happen to have a link for that YouTube video\channel do you?

I haven't had much time lately to test things out. Wife is very ill, kids birthday, work, etc...

I'll try and test the surfaces theory out as well as height and time.

I have noted erratic hovering stability over asphalt (my driveway) as well as grass (my yard) as well as both where they meet. The flying height was the standard approximate 4ft takeoff height. It would hold position for about 5 seconds and then slowly start drifting in every direction. The drifting would get greater until it was about 6-8ft from its original position.

I'll see if I can test out a stationary hover at a height of around 20ft and see how it goes.

If it's overheating how would I fix that? It already has a fan...take it apart and remove the shield, reapply thermal paste and a small thin heatsink and put it back together?

I think it was DroneCaptain/CaptainDrone , odd guy but he does make sense most of the time.
My drone takes around 15 seconds to switch to angle (GPS) mode and at times even more. IPS mode does not guarantee precise movements, my drone at times does act odd as well. I have done heavy modifications to the drone and also added the ability to use cheap batteries as seen in the attached pictures. Moving the compass to a new location solved some interesting interference issues. (that was someone @youtube idea)
Once you are above 6 feet, the drone will use GPS and no longer IPS which "can" be more stable but again no guarantee.
I was thinking about 3d printing the bottom cover to divert some air from the motors to the main board, then try to remove the fan ( that would cause the board fan sensor to trip, there are ways to trick it).
Also, my drone works ok even with slight center of gravity change due to the new battery location setup.
Now that you make my 2 brain cells think, the drone does act odd around the high power transformer ( serves 4 homes), at times complains about interference but the errors disappear quickly (drone would act very odd at that time ). So when you see your drone act odd, pay more attention to see if you see any errors shown on display.
I would not mess with the board and its thermal design, recipe for disaster. These things are not designed for outside "access" and will break on you.

Hope this helps.

-a

 

[j76]

I think it was DroneCaptain/CaptainDrone , odd guy but he does make sense most of the time.
My drone takes around 15 seconds to switch to angle (GPS) mode and at times even more. IPS mode does not guarantee precise movements, my drone at times does act odd as well. I have done heavy modifications to the drone and also added the ability to use cheap batteries as seen in the attached pictures. Moving the compass to a new location solved some interesting interference issues. (that was someone @youtube idea)
Once you are above 6 feet, the drone will use GPS and no longer IPS which "can" be more stable but again no guarantee.
I was thinking about 3d printing the bottom cover to divert some air from the motors to the main board, then try to remove the fan ( that would cause the board fan sensor to trip, there are ways to trick it).
Also, my drone works ok even with slight center of gravity change due to the new battery location setup.
Now that you make my 2 brain cells think, the drone does act odd around the high power transformer ( serves 4 homes), at times complains about interference but the errors disappear quickly (drone would act very odd at that time ). So when you see your drone act odd, pay more attention to see if you see any errors shown on display.
I would not mess with the board and its thermal design, recipe for disaster. These things are not designed for outside "access" and will break on you.

Hope this helps.

-a

I understand the battery mod completely. What is the small "black box" near the ultrasonic and optical sensor on the bottom rear of the drone? Is that the re-located compass?

As for interference, I pretty much live in the middle of nowhere. The nearest cell tower is a couple miles away and our house is more or less a cellular 'dead zone' as only ATT gets a single bar for signal. The nearest power transformer is at least a 150yds away in the opposite direction I'm flying.

A 3D printed bottom panel with ducting channels to feed air from the rotors over the bottom of the circuit board is a great idea. Intake slightly extended from the side, with a channel that directs the air over the circuit board, and exhausts under the drone on the opposite side. This way the intake channels don't interfere with each others cros-flow dynamics and the warm air is exhausted instead of circuilated inside the case like the existing fan.
When overheating was mentioned I already took it apart and looked at the thermals and they seem to be crap on this drone.

 

[Vasir]

I understand the battery mod completely. What is the small "black box" near the ultrasonic and optical sensor on the bottom rear of the drone? Is that the re-located compass?

As for interference, I pretty much live in the middle of nowhere. The nearest cell tower is a couple miles away and our house is more or less a cellular 'dead zone' as only ATT gets a single bar for signal. The nearest power transformer is at least a 150yds away in the opposite direction I'm flying.

A 3D printed bottom panel with ducting channels to feed air from the rotors over the bottom of the circuit board is a great idea. Intake slightly extended from the side, with a channel that directs the air over the circuit board, and exhausts under the drone on the opposite side. This way the intake channels don't interfere with each others cros-flow dynamics and the warm air is exhausted instead of circuilated inside the case like the existing fan.
When overheating was mentioned I already took it apart and looked at the thermals and they seem to be crap on this drone.

Yes it is and the stl file is on www.thingiverse.com/thing:4384528
Yes the board thermal design is crap, thus the warning. Looked at the logs and saw that CPU usage is on average around 40-50%, and my drone had lots of sensor issues when in China (~03/2019). Alt. was logged at times around 2000ft which is not correct. So the refurbs floating around might have some sensor issues or early pre-prod drones.