Wookong M GPS Mode - Fair Warning

[Av8Chuck]

I own 6 brands of Highend FC's. SuperX, A2, WKM, ZeroUAV Gemini (redundant), Naza V2, Hoverfly Pro and flown others.

AS of now I have had no issues with any FC that has not been found to be hardware related or stupidity.

I had an HC-800 Hex that I thought My superX flipped out on and I got mad at my SuperX. I slapped an A2 on the rig and low and behold the same problem surfaced. Ended up being a problem with motor #5. It shows no signs of a problem but after watching a video of my rig starting up you can see motor 5 is lame.

My Theory....

I believe a lot of problems come from people not setting up their radios for fail safe. I think if radio signal is lost the FC has it's fail safe protocol, and the TX/RX has it's protocol. So if you do not properly set up your radios failsafe to put the rec into neutral sticks, RTH on, other switches set to Atti, POI and IOC and all of that off, then I think that is causing the issue.

If your radios failsafe is not set right I think you are sending all kinds of confusing signals to the FC. I have seen guys with their Radio FS set to full throttle, fill right rudder etc, because they never checked it.

Futaba Super8's have the ability to set the TX failsafe. DOUBLE CHECK THAT.

There's probably no single right answer but I agree with what your saying. However setting up failsafe correctly might only be part of the problem/solution. When I had my first fly-away it was when I switched from Manual mode to Attitude mode and it instantly went to full throttle and simultaneously made a sharp left turn, I'm guessing that I didn't have failsafe setup correctly, but what caused it to go into failsafe? It was in a six foot hover about 10 feet away from me and it went into failsafe the instant I threw the mode switch.

My decision to leave DJI was in part because of the incessant firmware upgrades that seemed to break more than they fixed, because of the growing "fan" base it was getting increasingly difficult to get objective support [not really DJI's doing but nonetheless], and it just consistently did odd things that I didn't tell it to do - most of which didn't end in anything bad but I always felt a major relief that I landed without damaging anything.

With the HFPro and the SuperX the few "accidents" I've had I know immediately what happened and with all of them, knock on wood, they were caused by stupid pilot error and didn't cause any damage, so I have really begun to enjoy flying MR's again in a way that I don't think I could have with a DJI.

Also from a forum/customer support I just got tired of all the excuses and I started censoring my own posts in fear that I would say something that would be used later to make me feel like an idiot. For anyone who knows me I'm not good at filtering my posts so that says more about me and the nature of forums in general but with a the exception of a view people the SuperX thread is much more civil to one another, not nearly as much "MR Politics."

I think there's a lot more that goes into deciding which is the flight flight controller and when you need something that you can trust and rely on to make a living it shouldn't be based on a popularity contest...

IMHO.

 

[Shadrack]

I have never had a flight where I am going "WTF is it doing now?". If I did, I wouldn't have waited a while to switch.
My A2, S1000, Lightbridge setup so far works flawlessly.
Took some time getting everything setup and understood, but flawless so far.
Funny how there are people with no problems, and some with nightmares.
Think there is more to it than a straight up "DJI has a broken product" as there would be a lot more info if that was the case.

 

[SleepyC]

I think there's a lot more that goes into deciding which is the flight flight controller and when you need something that you can trust and rely on to make a living it shouldn't be based on a popularity contest...

IMHO.

I agree with this.
And for the record, I LOVE my superX's (have 4) I have well over 500 flights on SuperX's with not one failure. Also only one crash with a SuperX which was my fault. (I let the retracts pull power for the rec... don't ask, I was up late and made a dumb mistake)

In reality if you don't feel comfortable with our FC you will never do the best job you can.
I also think more people need to get some flights on a new rig before putting it to work.
I shoot for 25 flights.

10 flights with a brick the weight of my cam/gim mounted, then the actual gimbal with a different brick on it, and finally the full cam and him and the vib testing starts. Even if it's good I try to put 10 solid flights on the rig before it gets to work.

This is just my method, I'm sure others have their as well. What ever works!

 

[SleepyC]

Here's my Hex on a WKM getting ready to fly the M5. A dude passing by asked "Um why are you flying a brick around?" HAHAHA

 

[Burntpixel]

Here's my Hex on a WKM getting ready to fly the M5. A dude passing by asked "Um why are you flying a brick around?" HAHAHA

Best still evah! :highly_amused:

I,m flying a S800 Evo with WKM and a V2 IMU. So far everything has been performing pretty nicely. I still have a bit of micro vibrations in my aerial video,but I think after several more tweaks to the Z15 I'll be ok.

 

[Av8Chuck]

Is that a Jakub frame?

 

[SleepyC]

Is that a Jakub frame?

No sir, much nicer. It's an R/C Rotor and Aerial Media frame.
Cut in the USA!
http://www.shop.rotorsandaerialmedia.com/Multi-Rotor-Frames_c2.htm

 

[fredor]

One thing we must all bear in mind is that DJI will always have the most problems and by the same token the most units without problems, it would impossible to calculate percentages which would be the only true measure of reliability

 

[laurentsj]

Hello!

Sorry to read about your story, but you're not the only one!

I'm a professional architecture photographer who have been flying commercially since 2011, starting on droidworx/mikrokopter and switching to DJI-Wookong-S800
I've flown over 500 commercial flights, crashed 5 times, lost one machine at sea.

One error was defective mikrokopter GPS on the Droidworx-Mikrokopter causing a fly-away.
one error was most likely defective battery cell/voltage drop that caused the hexa to sea-crash.
the other 3 were pilot errors handling in gusty winds closed to obstacles.


I've also suffered 3 hard landings, that caused minimal damage but could have been fatal to the machine, and even to bystanders.

The first one was too long ago, and I must admit that I wasn't such a good pilot then, so I cannot tell exactly why the craft crashed.


I must stress that all my machines are professionally fitted and maintained, latest firmware updated.
I fly in GPS mode most of the time beyond 15 meters, switching to ATTI on take off and landing.

On both later and recent instances, behaviour was similar, both appeared coming back to land after an 8 minutes flight.

At about 20 meters distance, the S800 sudendly turned away in the oposite direction to home. I instantly switched to manual, stabilised the machine, then switched to ATTI to bring back the machine to land. At about 2 meters from the ground, the hexa went mad. In the first instance, it flipped. In the latest instance, despite applying control for a slow vertical landing, it went crashing sideways.

I was on a superyacht stern area, one of those collapsible deck pontoon. seconds before a model was being filmed in the chair. Crew ran over to check if there was damage to the super expensive yacht. I had the zenmuse gimbal poped off, a broken carbon tube on the chassis. I stil have no idea if the craft is good to fly again.

In the first instance, it was on a large property, 50 meters from the villa. The only possible interference was the staff handling portable VHS.

My question is this:

Admiting the first problem was caused via some GPS interference, then once i reverted back to ATTI, what could have caused the hexa to go crazy???

On the 2nd instance, i was on a huge 300ft yacht, with tons of electronics, crew with vhs, big compas and radars,


Do we know if large yacht compass cause interference?
what about electronics and VHS?
Can we shield the Wookong (and A2!)

We MUST be able to fly RELIABLE machines for commercial use. And IF GPS/ATTI modes are not reliable, then we need to fly manual for take off and landing. But we must know, and trust our gear!

 

[Burntpixel]

Do we know if large yacht compass cause interference?

It is quite possible. You are dealing with multiple sources of electro magnetic interference.

 

[laurentsj]

It is quite possible. You are dealing with multiple sources of electro magnetic interference.

THanks Bumpixel.

I read on about magnetic interference, plus the superstructure of the yacht is all steel.
But what about the instance at the villa?, I was in a garden

LAU.

 

[pfarmer]

Another real possibility is rf flood. While modern receivers are good at rejection they still can be flooded by a strong signal that prohibits processing of that from the transmitter. One needs to remember that you may have the failsafe setup correctly for the flight controller but not for the receiver defaults sent to the flight controller from the receiver such as lost of transmitter. Also DJI controllers can sense what appears to be a failed receiver an initiate it's own failsafe. With receiver failsafe make to setup defaults that are safe such as a high enough throttle to maintain altitude and neutral roll and yaw. Consider retracts down and if you desire a RTH or a slow descent to allow a hands off landing if the flight area allows. I test my settings at least once by turning off the transmitter or simply put it into a mode that stops transmission, first on the ground with props off and then a minimum setup in actual flight.

 

[laurentsj]

Hello Pfarmer
I wasn't flying the machine back in failsafe. I always fly in ATTI close to landing or takeoff. I'M going to soon switch to fly manual on approach and takeoff. That's the only way to avoid being surprised by erratic copter behaviour due most likely to radio/magnetic interference.
x

 

[sochin33]

I've been flying my X8 with WKM (5.26) for at least 60 flights and aside from accidentally flying too far away once which triggered FS, I have had no incidents.
However I occasionally notice some TBE which seems to somehow cure itself. When the TBE happens there is nothing from the iosd MarkII to indicate any weirdness. Where I fly I always have at least 8 sats.
Should I be concerned about the occasional TBE ?

 

[pfarmer]

Laurent are you sure it may not have entered into either the flight controller failsafe due to a sensed receiver issue by the flight controller or the receiver's own failsafe. Both of these are separate from a manually initiated RTH.

 

[pfarmer]

sochin33, at what altitude and control mode?

 

[sochin33]

sochin33, at what altitude and control mode?

Fairly low altitude,maybe 10-15 meters, and it happens in GPS mode.
i always take off and land in ATTI, but generally fly in GPS

 

[laurentsj]

pfarmer, the aircraft would not behave erratically during the initial failsafe return to base phase. In both instances, the machine went crazy. It's not that it stoped, hoovered, then climbed straight up, then took a clean and straight heading, as it doesn in a failsafe. The machine behaved like it had lost its horizon/IMU. I never realised that i had both switchs set to ATTI-ATTI-GPS on the Futaba 8FG. I now have them set as Manual-ATTI-GPS. Next time this occurs, I'll know for sure if it was indeed a radio/magnetic interference that sent false information to the IMU and compass/horizon on the aircraft. x

 

[pfarmer]

laurents, don't confuse the flight controller failsafe with a possible receiver failsafe, they are completely different. When the controller enters failsafe then it should simply follow DJI ' program for the type it is on. When a receiver goes into failsafe due for example loss of communication with the transmitter it typically will send a default set of instructions that the user enabled to the controller. Depending on your receiver it can be fairly easy to enable it without knowing you set it up and it will send a bunch of command that don't make any sense. For example on the DX9 - insert bind plug, place transmitter sticks and switches in default posistions, when receiver flashes orange remove bind plug and now turn on transmitter. Now consider what just happened. If you for example had your yaw and roll sticks off center, those are now your defaults on a loss of signal to your receiver. Your copter would spin and roll into a spiral.

 

[pfarmer]

sochin33 - the altitude you mention is above ground effect but just the right height for dirty air from building, trees, and other objects, I fly kites and you see this frequently even fairly far from the object. That may not be your case or it may be. Something I often encounter are those mini twisters like you would see if they were over a field kicking up dust. If only in GPS mode it is not unusual to have dropouts. If you were in a car they handle a dropout often by using motion sensing to update the navigation upon a temp lost of GPS signal. Your copter doesn't usually have that luxury. I have a separate GPS on my copter and it drops out pretty much on every trip out. I have a feeling the Naza does the same but I only see it if it is close enough and pointing my way. One source on GPS issues for all DJI controllers suggest keeping several inches between the GPS puck and the bec since there seems to be cases of interaction between them that changes with load. With TBE I often have wondered about the puck seeing interference from a motor or static from a prop. Once induced that interference could move as the motors change load trying to correct for it. When I see it, I notice it goes away if I hit the throttle up a little. When I first installed one puck several inches above the copter I noticed TBE all the time even though I correctly set the vertical offset. I lowered them since with the idea being to reduce what the puck is exposed to on the bottom of the puck, mine are located centered on top of a canopy made from an 8 inch microwave splatter shield.