NAZA H Control System Flight Test
I am very excited to get this thing in the air and see how well it works, and watch my heli just sit there in GPS mode. Below is my ongoing flight testing reports and thoughts.
The setup was pretty easy and mostly straight foreward. The only thing I could not figure out was the final setup step. The photos DJI used do not come close to telling you what they are thinking. I guessed that I had this section done correctly. Could be an issue, not sure.
Preflight photo in my test flight area.
Here are some photos after the crash.
A picture might be worth a 1000 words, but a video is priceless, enjoy.
And now for the 1000 words:
It started off with the gyro being reversed. I had the control setup correctly, but the gyro was reversed. The instructions were not clear on this at all in my opinion. There should be a test in the tail setup section to make sure this is done correctly. Maybe there is something and it is lost in the translation to english, but nothing stood out to me. So anyway, make sure you check this out in the ----------- section of the NAZA setup. After I fixed that issue it was time for lift off. As soon as it lifted it was very obvious gain was too high. In my setup with my JR9303 I am using the gear channel to control gain. Actually I think this is how DJI has you set it up. Because I am also using the flight mode switch for throttle control I wanted the gyro gain controlled by what head speed is selected. I use a mix function to achieve this. This is not a normal setup for me so I was not 100% sure what adjust when I first needed to change gyro gain. So I made a small change and lifed off, better but still not close. Whew!! at least I picked the correct adjustment. So I repeated this process about 10 - 12 times, but never was able to get the gyro to lock in solid with no oscillating.
So with the tail holding pretty well I decided it was time to switch to Atti mode. I have this setup on my Aux2 switch located on the right front of the transmitter. I have it setup with position 0 for Manual mode, position 1 for Atti mode, and position 2 for GPS Atti mode. (I will admit I am not used to using this switch except for my Hexcopter with NAZA-M control.It's used for IOC mode which I never really use either). So with the heli in a hover I flip the switch. The heli immediately starts to flip backwards towards me. This freaks me out a little so I go to flip back to manual mode, but accidentally go to GPS Atti mode, and at the same time I instinctively give forward cyclic control to stop the backwards flip. This is when the heli now flips forward and goes completely inverted. I pulled down on the collective stick to give negative pitch and hopefully push the heli up away from the ground. I have no idea if this had any effect or not because the heli was right at the ground in no time. Next instinct was to hit throttle hold to minimize damage.
Had I been more familiar with the Aux2 switch setting and actually got back into manual mode, this crash probably would not have happened. If I had been much higher and not flying in a small area where I had more room and time to react, this crash might not have happened. Well I can't change that now, so.... all I can do is ask why did the heli flip backwards when switched into Atti mode? Once back on my work bench I powered everything up and I did notice that when switching from manual to Atti mode the swash did move back slightly. So is something messed up in my setup, maybe (probably, because I've seen videos of others flying with hte NAZA). What did I do wrong? Hopefully I will figure this out during the rebuild. Are my servos too slow? That's all I have for now. Below are my questions that will hopefully be answered sometime soon.
What did I do wrong, or what went wrong???
1) Why did the heli flip backwards when switched into Atti mode?
A) After reading and learning, and thoughts from someone who has a working system, I had the gyro sensor set backwards. Normal control was fine, but when switched to Atti mode and using the
onboard sensors, the elevator (pitch) was reversed.
2) Is something messed up in my setup?
A) Yes, number 1 above.
3) What did I do wrong?
A) I did not understand the videos on the final setup step.
4) Are my servos too slow?
A) I am told that 0.20 sec servos are fast enough. But this guy has it installed in a 2 meter rotor span heli. I believe for the smaller helicopters you need faster servos. I have replaced my 0.16 sec
servos with 0.07 sec servos.
--------------------------------------------------------- Jan 15, 2013 ---------------------------------------------------------
Flight test #2 took place today and I am happy to report that all went well.
I only tested in Manual mode today because once again I was just in my side yard. When I test Atti and GPS Atti modes next I want to be at my local flying field so I have more room.
So what did I learn, and what did I do since the first test flight crash.
I have to say I really like the DJI NAZA stuff, but the directions are sometimes hard to follow, and easy to misunderstand. So I should have maybe done a little more research before attempting to test
the Atti mode the first time.
The DJI Final setup test should respond as follows: This is probably one of the most important steps to get right, even though they all matter.
1. The blades should move to positive collective, then negative, then back to neutral.
2. The swash should tilt forward, backwards, then back to neutral.
3. The swash should tilt left, right, then back to neutral.
4. The tail blades should pitch such that the nose would steer left, then right, and back to neutral. The direction will depend on your rotation.
I have also read on the HeliFreak forum that when your Tx sticks are moved up, or to the right, the sliders on the Common screen should all move to the right.
I use a JR9303 radio and for me to do this would mean the ESC I have would think I wanted it in the program state. That wouldn't work to well. I can't believe that DJI would do that kind of setup
because I think most ESC work the same using a minimum pulse for off (1mS), and a maximum pulse for 100% on (2mS). My test flight today proves this is not true. I am also pretty sure the Atti
and GPS Atti modes will work fine also.
Here's an onboard video from todays flight.
Well I have now successfully flown in all three control modes, Manual, Atti, and GPS Atti. I was only able to do one flight due to the cold weather freezing my hands. If on;y I lived down south. Anyway,
the heli flew great. Manual mode worked as before and as expected. I tested Atti mode once I was up in the air a ways. It worked very good to I thought considering the wind. I did very little stick input
to try to fly around in Atti mode. That will need more testing. GPS Atti mode worked great. Once I switched to GPS you could see the heli was locked in, even though it was windy it stayed in position.
Below is a video from onboard the heli. It should explain pretty good what is going on through out the vid. I look forward to more flight testing, but that might be two weeks away with current forecasts.