Flight Controllers; The Good, The Bad, and The Ugly

[RTRyder]

For those that have used ZeroUAV and DJI gear what are your general thoughts between the two? Any major issues/bugs with the ZeroUAV setups? Pros and cons of each?

I have both and have flown both on a Cinestar frame. The Zero system is more flexible when it comes to tuning ability and it will work well with larger props that the DJI WKM will not. Their major shortcoming is as mentioned, documentation and user interface, the system simply isn't as polished as some others I've used. I'm not currently flying the Zero system, last time I did it flipped on takeoff on the Cinestar bending the AV130 and breaking a prop. Not sure of what the problem might have been but I swapped back to the WKM and its been flying flawlessly since so IMO there are still some rough edges to the ZeroUAV that need to be eliminated before its ready for prime time.

The major issue I found with the Zero is the built in gimbal stabilization was unuseable at the time I was flying it, too few tuning parameters and overall it was not smooth on either axis, both Mk and DJI work much better. When the Cinestar flipped I was attempting to do the first test flight of the YS-X6 using a Photohigher RSGS to stabilize the AV130, had that been sucessful I might still have the system on the CS.

One other thing that can be a problem, the Ys-X6 is BIG, much bigger than a Wookong-M so mounting it to a frame can be challenging especially on a setup like the Cinestar when space for mounting the flight controller system is limited.

I think ZeroUAV has a good system with the right features and they have been very responsive supporting users worldwide, they simply need to refine some of the rough edges before it will be in the same league as the other major players. At some point I'll remount the YS-X6 on a frame, update the firmware, and give it another go, I expect by then most of the issues I saw previously will be resolved, time will tell...

Ken

 

[redridinghood]

I agree with the above. YS-X6 and now the X4 are better systems than the wk and naza.
Zero Uav took everything that was wrong with DJI and made a V2 hardware that outperforms Wk.

I sold mine because I thought I needed the Zenmuse. Lately I am not sure I made the right decision.

 

[R_Lefebvre]

I'm not currently flying the Zero system, last time I did it flipped on takeoff on the Cinestar bending the AV130 and breaking a prop. Not sure of what the problem might have been but I swapped back to the WKM and its been flying flawlessly since so IMO there are still some rough edges to the ZeroUAV that need to be eliminated before its ready for prime time.

There might not actually be a problem that needs to be fixed. This is simply the trade-off that must be made when deciding on what tuning factors to allow. DJI really dumbs down the tuning factors, so that it is successful for 90% of people without any weird flipping problems. But then that also prevents it from working well on all setups. The flip was probably just a tuning issue. We have the same problem, in that we allow users to enter almost any value they want. Some people struggle having this much flexibility, and just can't get it working, so they sell it and just get a DJI and are happy. Others have no issue at all. That's what my "flip testing video" was about. I was trying to FORCE it to flip on take-off because some people had complained about it. But it just won't do it the way I have it tuned.

One of the other developers has the YS-X6 system, and actually likes it quite a lot. It sounds like a good system. I'd try that before DJI, because the DJI is just so limited in it's capability. It does a few things, but it does them simply, and well. If that's what you're looking for, no problem. But some people want more than just the basics.

I'd love to have an Android app for our system! How does it communicate, is it wifi? Bluetooth?

 

[RTRyder]

There might not actually be a problem that needs to be fixed. This is simply the trade-off that must be made when deciding on what tuning factors to allow. DJI really dumbs down the tuning factors, so that it is successful for 90% of people without any weird flipping problems. But then that also prevents it from working well on all setups. The flip was probably just a tuning issue. We have the same problem, in that we allow users to enter almost any value they want. Some people struggle having this much flexibility, and just can't get it working, so they sell it and just get a DJI and are happy. Others have no issue at all. That's what my "flip testing video" was about. I was trying to FORCE it to flip on take-off because some people had complained about it. But it just won't do it the way I have it tuned.

One of the other developers has the YS-X6 system, and actually likes it quite a lot. It sounds like a good system. I'd try that before DJI, because the DJI is just so limited in it's capability. It does a few things, but it does them simply, and well. If that's what you're looking for, no problem. But some people want more than just the basics.

I'd love to have an Android app for our system! How does it communicate, is it wifi? Bluetooth?

Thing is it had a number of successful flights prior to the flip and no changes were made to the setup between the last flight and the flip. The only thing that did happen was the CS sat on the shelf for a couple of weeks without being powered up, I installed the RSGS on the AV130 using an independant power supply to feed the RSGS and gimbal servos, that was the only change I made, end result instant flip on takeoff and a couple hundred $$$ of damage to the AV130.

Without making any other changes I switched back to the WKM controller and its been flying perfectly since so the only conclusion I can draw from all of it was that there was some issue with the YS-X6. At that point in time they were quickly going through a lot of firmware revs so my assumption is that I just happened to have one of the buggy versions and somehow managed to trigger a flaw in the code. In any case I wasn't willing to risk further expensive damage, the YS was retired to the bench until I have time to put in on a test frame and fly it a bit with the most recent firmware, it will have to earn my trust again before it sees duty on expensive hardware.

The standard communication between the YS and the ground is wifi, in my testing I found the range to be far too limited to be of any real use other than to check the status of the system prior to takeoff and for making parameter changes in the field. I have the 2.4gHz data modem upgrade that hasn't even been taken out of the packaging yet, I'll get to that when I bring the YS back online.

Ken

P.S. I've been flying Mikrokopters for a few years now so I'm not unfamiliar with making tuning parameter changes and the potential consequences of making the wrong choice. I also have a couple Multiwii boards that fly rather nicely and are a lot more finicky to tune than an MK or YS-X6 but fly ever so nicely when properly tuned

 

[R_Lefebvre]

Yes, it could have been a bug. But it could have also been a very common problem which is I-term ramp up while sitting on the ground. That is what I was testing in my video. After throttle up, if you sit on the ground for any time, it will wind up an I-term because it is trying to move, and it can't because the gear is on the ground. This happens because either the ground isn't level, or you move the pitch/roll stick while it's on the ground. Soon as you actually lift off, this wound-up I-term forces the flip.

It can be prevented by using adequate P and D-terms. But that is hard to tune properly.

It can also be prevented by simply putting a strong limit on the I-term wind-up. This is the easy way. But it also limits the ability of the FC to counter in-flight failures.

So this goes back to my point. Some flight controllers make it easy to tune, but that removes performance. Others are harder to tune because they are more flexible. It irks me when I see comments from users that a FC is no good, because they couldn't figure out how to use it properly.

Now I can't say that this tuning scenario is what caused your flip, but it is one very likely cause. It's an easy explanation why it worked most days, and then one day it just flipped. I'm just making this statement to try and broaden the discussion. This is much more complex of a topic than simply "This one is easy to use so it's the best". Again, if that's all you're interested in, fine. But it's also known that the easy ones may not perform as well in all situations. For example, there are some MR's which the DJI can simply not fly, while other FC's have no problem with the same airframe.

 

[Kari]

Ken,

I think you should get over your flip and give YS-X6 another shot, or sell it but not tell again and again one single flip half year ago when YS-X6 was just released some weeks or days before. I don't remember anyone else had this kind of flipping so i doubt it even was a bug nor fault in YS. I have flipped mine once when i set roll sensitivity value accidentally to 10 instead of 100 so it was 100% my own fault. I'm sure it's was not the case in your flip but i think you can not judge YS-X6 as a controller based on experience of just few flights until you gave up. YS-X6 has gone long way since then. There are some roughness in GCS user interface but that's not essential in my opinion. If want eye candy then should be looking for something else, maybe dji is the most "apple-like" of the controllers. Nowadays also manual is much more readable than it was half year ago. Yeah, not perfect or beautiful but you can get the information what's needed for installation if red patiently.

 

[nicwilke]

I'd love to have an Android app for our system! How does it communicate, is it wifi? Bluetooth?

It works with either datalink, or wifi. The basic unit comes with 2 wifi modules. The FC sends data down to the ground wifi unit. If you want bigger range, you get the datalink module that swaps out as easy as a plug and play on your crazy. Then the ground datalink connects to another wifi module, and you connect your phone/tablet via wifi. The GCS app also helps enable other functions like target lock so you don't have to remember the flicking switch codes to enable functions. I've not had any flip issues.

 

[elorest]

I've used kk 2.0, dji naza and Ardupilot apm 2.5. DJI naza was great in that it was easy to set up. Arducopter takes a lot more work but is easily just as stable although achieving finely tuned hover, RTH and position hold takes a bit. The KK board was inferior in every aspect I tried but is still a cheap way to get a somewhat stable machine in the air.

 

[Fat Corgi]

It's over a year since this was last discussed. With the new inclusion of new firmware, and new products on the market, have people's opinions changed greatly. I'm interested in a flight controller for a large to midsize octo for AP work. Currently flying a NAZA V2 on a smaller rig, and am use to flying manual for single rotors. Have any of the issues from the Wookong systems been ironed out?

 

[jfro]

I just put a Naza V2 on an x8 and I'm happy with it. 18lbs auw. I had a HoverflyPro on a small X8, then on this X8 I previously had the xAircraft which I didn't like at all.
Here's some footage from the 2nd time out with the Naza on the X8. X8 and gimbal are my own custom built designs. Down to my post called Bluff Home.

http://www.multirotorforums.com/showthread.php?113-Show-what-you-filmed/page353

 

[Fat Corgi]

So jfro, you changed from the Hoverfly Pro to a NAZA V2 on your X8. What was the reasoning behind this?

 

[jfro]

So jfro, you changed from the Hoverfly Pro to a NAZA V2 on your X8. What was the reasoning behind this?

Convoluted answer, short answer is had issues with X8 / Hoverfly problem and while waiting on FC from Hoverfly, put an xAircraft on. 8 months later, gave up on xAircraft on x8. Was happy with Naza on 550mm quad. Tried it on 650 quad with bigger motors and loved it. Few weeks ago, I tried in on X8 and so far like it.

Long story.
Went from HFP to xAircraft, to replacement HFP, back to Xaircraft last year on X8 with 770kv motors.
While messing with all this, built Naza V2 450 then converted to 550mm quad. Flew great and got lots of experience flying it. Less stressful to fly also as a newbie.
Winter came. 550 quad got a Pixhawk.
Built new 650 quad for Naza & 3520 500kv motors with mid size gimbal.
Built new 880mm X8 with 3515 / 400kv motors and used xairCraft.
Spent spring dialing and fussing with 2 gimbals on 650 and x8.
Loved the way Naza/650 flew and was getting it dialed in to handle some wind from the gimbals standpoint. Video was excellent.
x8 on xAircraft flew and filmed nicely in calm winds but not so good in wind. X8 was fidgety in wind no matter on many gain settings I tried.
Finally, 3 weeks ago, after talking with a few folks, decided to swap Naza and xAircraft on the quad and x8.
Now, happy with x8/Naza and getting good video. Haven't been in over 15mph wind yet, so don't know there.
Not as happy with 650 quad now, but still tweaking. Video is good in low wind, but when wind starts blowing, I'm a jumping around a bit more than I think the Naza did. Video is OK up to a point.

HFP still sitting in drawer not knowing what to do with it. The Naza has been problem free and it flies nicely on everything it's been on. I'm mostly slow flying with camera's rolling. I get some extra security knowing I can flip a switch and get the GPS to hold position when I lose orientation. Little bit of a security blanket as I'm still logging time learning to fly.

Since I paid for 8 motor config for the xAircraft and it's not going back on the x8, I'm contemplating selling it and buying another Naza V2 for my 650 w/ 3520's and I should get some 100's of dollars back. $600 vs $300, why do I have the more expensive one on a quad?

I've only had x8 and Naza together for a few outings, but so far, I can't find any fault with it. Got some great video on last outing. I'm pretty careful with my setup and making sure I have a good GPS lock before lift off, and making sure everything is working and tied down. Only slightly nervous about fly aways.

Way too much time and money spent to get here, but now pretty happy. Hoping to get the Pixhawk dialed in to try on a larger MR sometime.

 

[Fat Corgi]

That's quite the adventure jfro.

I too have a NAZA V2, which is currently on a 550 hexa, and like the way that it flies. I agree, having the ability to switch to GPS mode, when needed is handy. Am currently putting a midsize octocopter together, and am still debating which flight control system to go with. At this stage it's between the Wookong or a Hoverfly. I don't know enough about the others, but am hoping the Wookong flies just as well, if not better than the NAZA. The fly away issues experienced by the DJI equipment do scare the pants off me, but I am pretty fastidious when it comes to putting things together and testing things properly.

 

[mephisto]

I have to disaggree with the Statement that MK comes with no Support.

It's probably the only commercial System where the Dev's actively answer the forums. Also - if you have a problem you can even send in your Copter and they will look for it. You won't get that from DJI. Another big + is the fact that the sourcecode is available and thereby well audited by the community. No mysterious missbehaviours which can't be tracked down, due to limited logging and telemetry Options. The Logging + Telemetry of the MK is outstanding compared to Naza's for example. You also get an extensive Ecosystem of 3rd Party developments (Portable Copter tool, FollowME, several OSD's, Light Applications etc), which can be used for the MK.

The "downside" is, that it's not plug'n'play, you have to use a solder iron if you don't buy the ARF Version. On the other hand you get sensitized for Multirotor Basics, which isn't too bad.

I fly MK since 2008 now, and all incidents I had in the beginning were caused by my own faults - from which I learned. No total loss, and no flyaways, just some broken props.. Roughly 3000 minutes crashfree now. I wouldn't change.

 

[vispaaja]

Me and my colleagues have been very pleased with Xaircraft SuperX controllers and also their customer support. Compared to Naza, it seems to work better with larger frames and doesn't really seem to require much or ANY tuning. Have tried it on 3kg gopro quad, 6kg flat hexa, 6kg X8 and 10kg X8 with the factory settings (only selected frame type) and they all feel the same; good wind stability and no jitters or wobbles. So far haven't witnessed any nasty surprises or major issues with them. However, I DID get a broken OSD and Stella gimbal from Xaircraft which made me a bit cautious of their build quality..

For small "fun" quads I've liked Multiwii boards (nanowii), they don't cost much and have been excellent and reliable in all weather conditions that I have ever witnessed. The downside ofcourse it that they are not plug and play, but that's why I got a similar quad that my friend has and just copied his settings. For a beginner they can be a nightmare.

Also tried YS-X6 but for that price I would have expected more than cheap china plastic and a horrible GUI that had some nasty bugs. It flew quite well though.