NAZA height drop in fast forward flight.....

[ChrisViperM]

I have a NAZA bolted on a TBS Disco, and it's working fine. The only trouble I have is the Disco is losing height when flying fast forward in ATTI/ ATTI GPS (doesn't make any difference), so in order to keep my height, I have to push the trottle stick. I tried everything....obviously every dirty trick with the settings, re-calibrating GPS/compass, re-flashing Naza firmware, different props....you name it, I did it. It's pretty annoying when you fly fast FPV in low altitude.

It's holding position fine when hovering or slow flying arround, but it doesn't like flying fast forward without slowly loosing altitude. After searching the net, the main message is: That's what it is.....will hold position when hoovering, but will loose height when speeding.

Now my idea is to program a mixer in my Futaba to automatically increase throttle when flying fast forward......anyone done this already....?????


Chris

 

[Dewster]

My Y6 does the same in fast forward flight. It do do that on my flat Hexa on an earlier firmware version. I was informed that adjusting the vertical gains could be the solution. My craft maintains perfect altitude hold at hover or slow flying speed. Rapid flight forward has me adjusting the throttle to compensate for descent. I was trying to get a low level flight above water and then climb out, but during the course my craft kept getting closer, and closer, so naturally I aborted that flight plan.

Ill have to play with the gains.

 

[PeterLester]

Did you adjust vertical gain way up toward maximum of 250 or 255? I found that helped me a lot with the same situation in Attitude and GPS......but not entirely...
turns out my 6 motors on my RCT800 are not quite powerful enough for fast level flight with the extra MR weight.

I have a NAZA bolted on a TBS Disco, and it's working fine. The only trouble I have is the Disco is losing height when flying fast forward in ATTI/ ATTI GPS (doesn't make any difference), so in order to keep my height, I have to push the trottle stick. I tried everything....obviously every dirty trick with the settings, re-calibrating GPS/compass, re-flashing Naza firmware, different props....you name it, I did it. It's pretty annoying when you fly fast FPV in low altitude.

It's holding position fine when hovering or slow flying arround, but it doesn't like flying fast forward without slowly loosing altitude. After searching the net, the main message is: That's what it is.....will hold position when hoovering, but will loose height when speeding.

Now my idea is to program a mixer in my Futaba to automatically increase throttle when flying fast forward......anyone done this already....?????


Chris

 

[ChrisViperM]

Thanks guys....I was not sure how high I can go with the vertical gains. I maxed it at 190, so will try cranking it up to 250. My motors - 950kv TBS motors - are powerful enough, tried 3S and 4S Lipo's with 9" and 10" blades in any combination....didn't help. Once the weather is better, I'll try the gain trick, if that doesn't help, I try some mixing magic in the Futaba.

Chris

 

[BorisS]

Thanks guys....I was not sure how high I can go with the vertical gains. I maxed it at 190, so will try cranking it up to 250. My motors - 950kv TBS motors - are powerful enough, tried 3S and 4S Lipo's with 9" and 10" blades in any combination....didn't help. Once the weather is better, I'll try the gain trick, if that doesn't help, I try some mixing magic in the Futaba.

Chris

Chris to be honest i dont think bring the vertical gains even higher will help you ! I have a similar setup and i think my vertical gains are around 120 or something that low. I suspect more vibration messing with the z acc !

Boris

 

[Bartman]

Chris to be honest i dont think bring the vertical gains even higher will help you ! I have a similar setup and i think my vertical gains are around 120 or something that low. I suspect more vibration messing with the z acc !

Boris

guys,

are you talking about being in altitude hold while flying forward? i believe this is a matter of running out of lift and gains not being able to compensate enough. if i can i'll do a quick video later tonight to try to explain better.

bart

 

[ChrisViperM]

guys,

are you talking about being in altitude hold while flying forward? i believe this is a matter of running out of lift and gains not being able to compensate enough. if i can i'll do a quick video later tonight to try to explain better.

bart

Thanks Boss...

The funny part is: If I fly fast forward from hoovering in AltMode, the bird flies forward, but starts to lose height.....if I push the throttle slightly at the same time, it keeps the height, if I really push the trottle, it not only keeps height, it gains height like a rocket....so that tells me the "hardware" is strong enough to cope, but I just guess the code of the FC is just not made for FastForward and keeping the height.....just for hoovering and slow flying.


Chris

 

[BorisS]

Its a strange one on both my naza in the CX and on the TBS i push them full on attitude and they hold nicely ! by the ways chris i am going to be probaly in junse two weeks in the irrsee mondsee region at our house, maybe it would be fun to meet up and do some flying !

Boris

 

[ChrisViperM]

Its a strange one on both my naza in the CX and on the TBS i push them full on attitude and they hold nicely !

I will just re-flash the Naza and start from scratch.....maybe the EzUHF is also some how "involved", but wouldn't know why.....will try with a normal Futaba receiver.

by the ways chris i am going to be probaly in junse two weeks in the irrsee mondsee region at our house, maybe it would be fun to meet up and do some flying !

would be really great....I am all in.....just hope for good weather.


Chris

 

[glacier51]

Guys, in the real helicopter world, if you start a rapid horizontal acceleration from a hover without adding power, the machine has to share "lift" with the new demand for "thrust", so it descends.

One rule of thumb is the normal hover height of a helicopter is determined by its ability to enter forward flight from the hover without touching the ground.

In addition, props get very little, if any, increase in efficiency entering forward flight unlike a rotor blade.

 

[b0nafide]

I always understood that in GPS mode it should maintain the height while in full forward flight. This is because the Naza shouldn't allow you to tilt the MR forward enough it cause the loss in height. In Atti mode though because the Naza allows for a more agressive tilt forward the MR will loose height.

I noticed this same issue on my F450 the other day after a complete teardown.

My To Do List includes:
- IMU calibration
- Confirm X, Y, Z values of my GPS (I'm pretty sure this is off right now)
- Use different props on the next flight to eliminate any possible vibration concerns

Post what you do afterwards and we'll compare notes.

 

[Dewster]

Good info. How are the small quads doing fast forward FPV flight without smacking into the ground?

I can't remember having a problem with losing altitude on fast forward flights with my flat hexa.

Maybe I was carrying a light load.

 

[MultiCopterFPV]

Any news on a solution for you? My Naza-M just started doing this today. I was in a hover inside with no wind and it just tried to shoot up 3 feet for no reason at all. Then I was hovering outside and it dropped 2 feet out of no where. Had I not been quick on the stick it would have crashed. I am afraid to fly. Any ideas or suggestions. I am really upset right now and don't know what to do.

 

[PeterLester]

How many flights have you had with it so far? Did you cover the side of the controller with black tape as recommended by others in this forum? It resolves an issue with sunlight affecting the electronics which is identified as rapid altitude changes for no apparent reason.

If you have done this already.... check for vibration issues...... I have heard that MR frame vibration can reek havoc with the controller resulting in a fly away or worse. If vibration damage is significant, your controller might not be repairable. Hoping for the best for you. I am having similar issues.

Any news on a solution for you? My Naza-M just started doing this today. I was in a hover inside with no wind and it just tried to shoot up 3 feet for no reason at all. Then I was hovering outside and it dropped 2 feet out of no where. Had I not been quick on the stick it would have crashed. I am afraid to fly. Any ideas or suggestions. I am really upset right now and don't know what to do.

 

[Nicodema]

Just a thought, could it be Bernoulli? If the the Naza is exposed to airflow, thn rapid movement could fool the altimeter into thinking it is higher (lower pressure), hence causing a drop. That would be a stable drop, proportional to velocity though, not a gradual sinking. Which do you see?

could certainly be a red herring, and vibrations are always problematic for these systems

 

[Bartman]

Just a thought, could it be Bernoulli? If the the Naza is exposed to airflow, thn rapid movement could fool the altimeter into thinking it is higher (lower pressure), hence causing a drop. That would be a stable drop, proportional to velocity though, not a gradual sinking. Which do you see?

could certainly be a red herring, and vibrations are always problematic for these systems

that's an interesting thought Nicodema. to be Bernoulli's principle though I think you'd have to have the pressure sensor in a place where airflow over a dome or something is making the internal air pressure under the dome go down. most flamewheels have nothing on top and if the heli is being tilted way forward then I'd guess there's actually a bit of ram air pressure being generated which would make the NAZA read lower altitude and climb.

there's probably a little of everything contributing to it.

 

[ChrisViperM]

Thanks guys for all the input....


Just a few facts about my bird: It's a Team Blacksheep Discovery, Motors/ESC's are from here: http://www.kopterworx.com/TBS-Motor/TBS-KW2-motor-set, props are from Graupner, 9x5 and 10x5, motors and props are perfectly balanced, tried 4S and 3S Lipo's in variation with the different props, NAZA is covered with black tape.

When I am hoovering or slowly flying arround, it keeps perfectly its height, doesn't matter if ATTI hold or GPS hold....only when I push it to a fast forward flight, it gains speed very fast (up to 65 KmH), but at the same time it slowly looses hight....about 1m every 200m distance. When I add slighly some throttle, I can keep it on its hight, but this is a bit tricky...if throttle is a bit too much, it does exactly the opposite and starts to rise....this tells me the power of the hardware is more than sufficient, I know my vibrations are down to a minimum (checked with a smartphone app), and airflow can't be the problem since the front of the TBS is basically closed by the GoPro and FPV cam.


I will try the new Firmware on weekend and see if it improves, but I am sceptical. One thing I could not figure out: Obviously the NAZA needs a pressure sensor to maintain a certain hight, but I could not find any opening in the NAZA case. I thought I might have accidentally covered any opening in the NAZA case by putting the tape on, but there is no hole anywhere....so how does the NAZA pressure sensor work ??????

I was reading again in different forums that this hight drop is pretty common ( especially when flying above 50 KmH)....looks like the NAZA can't cope with higher forward speeds....


PS: Found a good thread at FPV-Hub: http://www.fpvhub.com/index.php?topic=11719.0 The guy there (Iceman) explains a few things about gain pretty well.....looks like you have to set it either for good hoovering performance (higher gains) or better flight performance (lower gains)...
Makes sense to me....have to try it




Chris

 

[PeterLester]

On the NAZA the baro pressure port/hole is very small and located at the front or back end of the controller/imu module if I remember correctly.
Unless they made a design change.
However I noticed that the WKM system does not seem to have a baro pressure port/hole anywhere.....!!!

Thanks for the hotlink..... always more too learn on PID loop control etc. with these complex MRs.:shame:

Thanks guys for all the input....


Just a few facts about my bird: It's a Team Blacksheep Discovery, Motors/ESC's are from here: http://www.kopterworx.com/TBS-Motor/TBS-KW2-motor-set, props are from Graupner, 9x5 and 10x5, motors and props are perfectly balanced, tried 4S and 3S Lipo's in variation with the different props, NAZA is covered with black tape.

When I am hoovering or slowly flying arround, it keeps perfectly its height, doesn't matter if ATTI hold or GPS hold....only when I push it to a fast forward flight, it gains speed very fast (up to 65 KmH), but at the same time it slowly looses hight....about 1m every 200m distance. When I add slighly some throttle, I can keep it on its hight, but this is a bit tricky...if throttle is a bit too much, it does exactly the opposite and starts to rise....this tells me the power of the hardware is more than sufficient, I know my vibrations are down to a minimum (checked with a smartphone app), and airflow can't be the problem since the front of the TBS is basically closed by the GoPro and FPV cam.


I will try the new Firmware on weekend and see if it improves, but I am sceptical. One thing I could not figure out: Obviously the NAZA needs a pressure sensor to maintain a certain hight, but I could not find any opening in the NAZA case. I thought I might have accidentally covered any opening in the NAZA case by putting the tape on, but there is no hole anywhere....so how does the NAZA pressure sensor work ??????

I was reading again in different forums that this hight drop is pretty common ( especially when flying above 50 KmH)....looks like the NAZA can't cope with higher forward speeds....


PS: Found a good thread at FPV-Hub: http://www.fpvhub.com/index.php?topic=11719.0 The guy there (Iceman) explains a few things about gain pretty well.....looks like you have to set it either for good hoovering performance (higher gains) or better flight performance (lower gains)...
Makes sense to me....have to try it




Chris

 

[MultiCopterFPV]

Chris, I too am experiencing drops while flying and it will also randomly gain altitude on me. I am starting to wonder if it is a motor / esc not having a good connection. Tonight I plan on stripping my F550 back down to nothing. When it comes to computers I know for a fact sometimes you just have to unplug and plug stuff back in sometimes. It could be a loose connection point somewhere or feed back on the power. I'll let you know what I find.

Anyone know of a way to test out an ESC to see if its good or not?