Problem with NAZA-H

[eylau2005]

Originally Posted by nightflyr

I agree with Tahoe Ed,
The Naza - H fail safe works exactly as described in the instructions.
If you want the helicopter to do something different if it engages fail safe while in manual mode you'll need to set your Rx fail safe and rebind accordingly.

would pls show me where DJI does exactly say/state how Naza H FS shoul be working?? I'm struggling to find this exact info but couldn't in any documents in their web site?? TKs so much...Eylau

[nightflyr]

[ame]http://www.youtube.com/watch?v=_N9KJEtcNMI[/ame]

[eylau2005]

Sorry nightflyr
but the video doesn't say how The Naza - H fail safe works exactly .....
It says how to set up the 3 position MODE switch and about a "Ghost" 4th value (44 I guess) to be used by Fail-safe function. But where does it say how to customize Naza H FS function??? I would recommend to be very careful to play with Naza H FS functionality (?????) you could get unexpected results different from what you exactly know about Naza H FS ...In fact people are reporting different behaviors when they test or switch off the radio Not going to buy it with current firmware release ...hope it helps and enjoy it .

[nightflyr]

The Naza fail safe will put the helicopter into a GPS/ATTI hover until signal is regained by the Rx

[zeeflyboy]

Originally Posted by nightflyr

The Naza fail safe will put the helicopter into a GPS/ATTI hover until signal is regained by the Rx

Unless you were in manual mode when you lost signal, in which case it'll crash your helicopter.

That isn't explicitly mentioned anywhere in the software that I've seen, and its a rather important point.

Many people, myself included, would expect failsafe to engage when the rx failsafes. But this isn't always the case.

Either it's intentional, in which case DJI need to be absolutely clear about it, or its a bug related to capturing zero throttle just before the unit goes into the auto hover.

Given the complete lack of info about it, and the fact that the Naza-M will auto hover or RTH from any mode, I'm inclined to believe its a bug.

[nightflyr]

Consider post #77

[zeeflyboy]

Yup, which is the work around (and thanks for doing the testing by the way)

That's fine for us, as we know about it now... But what about all the other users flying around in manual and expecting it to failsafe hover as, in my opinion, it's fair to expect given you've setup the unit to enter failsafe as per instructions.

DJI needs to be absolutely explicit about the fact that if you are flying in manual the helicopter will not auto hover on loss of signal if you have followed the instructions and set the failsafe mode according to how they describe.

Either that, or fix what I suspect is a bug related to throttle capture. Setting a suitable throttle in your failsafe mode may fix it, but is not the most advisable way of setting things up. The unit should just go to the previous throttle position it saw in the instant before failsafe engaged.... This would also ensure that if failsafe is engaged accidentally on the ground after landing by turning off the radio, nothing would happen since in the instant before engagement it had zero throttle anyway.

[R_Lefebvre]

The unit should just go to the previous throttle position it saw in the instant before failsafe engaged....

An even better, and simpler thing to do would be to simply have a setting: F/S Throttle. What throttle will it go to when F/S is engaged.

Done. Couldn't be simpler.

[eylau2005]

Originally Posted by zeeflyboy

Yup, which is the work around (and thanks for doing the testing by the way)

That's fine for us, as we know about it now... But what about all the other users flying around in manual and expecting it to failsafe hover as, in my opinion, it's fair to expect given you've setup the unit to enter failsafe as per instructions.

DJI needs to be absolutely explicit about the fact that if you are flying in manual the helicopter will not auto hover on loss of signal if you have followed the instructions and set the failsafe mode according to how they describe.

Either that, or fix what I suspect is a bug related to throttle capture. Setting a suitable throttle in your failsafe mode may fix it, but is not the most advisable way of setting things up. The unit should just go to the previous throttle position it saw in the instant before failsafe engaged.... This would also ensure that if failsafe is engaged accidentally on the ground after landing by turning off the radio, nothing would happen since in the instant before engagement it had zero throttle anyway.

I'm with you zeeflyboy.. but it is not a bug ..it is a piece of missing deign (dbad one in my view) when downsizing a product model A to a B version, cheaper and with less functionality but trying to keep/reusing some piece in the SW and some not in the firmware.... see these findings..
http://www.rcgroups.com/forums/showthread.php?t=1788756 last post
Naza H doesn't have any internal FS functionality/option at all even to be customized (like THR setting as R_Lefebvre suggestion) as opposed to his higher level/$ unit the WKH.....

people stating they can confirm a product works as design, not knowing what the design is...are really dangers when talking about safety in this hobby...FS is "so safe matter that can injure someone and for free" .... even workaround are fixes to a well know problem/issue not to something you are assuming... sorry but talking on safety matter get me pissed.......

[nightflyr]

The issue(s) concerning how the Naza fail safe operates and the draw backs are pretty straight forward .

Is the Naza-H perfect?... Absolutely not.

Does the on-board fail safe cover all flight modes... Absolutely not.

Are there ways around how it presently operates.... Absolutely, providing you have a comprehensive understanding your equipment.
That's not to say the "work around(s) are perfect,but you are limited to what the operational limits that the platform has available.

Should DJI address these safety issues.... Absolutely.

It was stated very early on that a fail safe RTH function should be incorporated.
DJIs response... there will be no RTH function for the Naza-H.

Everyone has their own thoughts and opinions on what would be / should be a " good fail safe".

I have no vested interest either way concerning these matters.
What the manufacturer decides in the end is what it will be.
If a pilot wishes to purchase the system as it stands, I would hope that they do their research and gather as much information as possible.

I personally enjoy a challenge, so to tweak around with setups, it doesn't deter or frighten me.
If it works all the better, if it crashes... that is the price I'll pay to follow that path.
Anyone who knows me, knows how I work, and what I will do especially when it is said "it can't be done"
And before anyone jumps in and states with the " it's not safe...." line of logic.
I test fly in a totally isolated area.. so there is no risk of damage or harm to people or property.

As I stated ..is it perfect?, or even close?
Not in my book, but it can be improved (manipulated) a bit.

Hopefully DJI will take another look at what their customers are saying and reevaluate their position on such matters.

[R_Lefebvre]

What the manufacturer decides in the end is what it will be.

That's fine.

If DJI have intentionally made the decision to crash the heli if it goes into FS from manual mode, then they should clearly state that. As I understand it right now, it is not clear to the users, which is what is dangerous, because any reasonable person who is looking at the capability of the Naza-H would expect that at the least, it would go into a stable hover if it FS's from ANY flight mode, not just some of them.

To me it's illogical, but if they have chosen it for some reason, then state it very clearly.

[nightflyr]

Agreed, that is DJI's issue and should clearly be noted.

[cbergen]

A couple of items to note;

The manual DOES state this,

In Manual Mode, all the operation is the same as normal helicopter, depending on experience

Consider that IF your heli goes into failsafe WITHOUT the Naza installed, what happens?

It also states;

When you switch to ATTI. Mode or GPS ATTI. Mode, the NAZA will record the throttle position. The
throttle will hold this position while in ATTI. Mode or GPS ATTI. Mode, so the motor rotation speed
cannot be changed. The motor will not stop even if the throttle stick is at the bottom position. Please
switch to the Manual Mode if you need to change the motor rotate speed or even stop the motor

When you switch modes, THEN it records throttle. In Manual mode it is operating just as if the Naza were not even installed. Which includes going into failsafe.

[R_Lefebvre]

Consider that IF your heli goes into failsafe WITHOUT the Naza installed, what happens?

With a regular FBL controller, I would program my Rx to output center sticks, throttled up. Then at least if I get a blip of F/S, it will maintain rotor speed and coast, and if I can regain control before it hits, maybe I can save it.

Is it not the case here where, with the Naza-H, if you program it with the "phantom 4th mode" for failsafe, no matter what you do with the failsafe program in the Rx, if you were flying in manual mode before the F/S mode is triggered, it will shut down the motor?

So even if you were 200 feet up in the air, the motor shuts down, now it's out of control and auto-ing. If you get control back, not only do you have to deal with a loss of orientation, but also low rotor speed?

1) Regarding failsafe, I tested mine on the bench, blades off and in manual mode when failsafe kicks in the motor powers down (just the way I set my failsafe up), but in atti or GPS atti mode it keeps the motor powered at the same setting it was in when I switched off the radio. So were you flying in manual mode when these failsafes happened or in gps/atti mode?

For people who have not flown with telemetry, you might be surprised at how often the signal drops out momentarily in flight, even at short range. Anytime the Rx antenna is on the far side of the carbon fiber frame, it's trouble. Luckily, most Rx do not trigger their FS output instantly on signal loss. They will normally just hold the last position until the signal loss goes beyond 1 second.

[flim63]

Originally Posted by cbergen

It also states;



When you switch modes, THEN it records throttle. In Manual mode it is operating just as if the Naza were not even installed. Which includes going into failsafe.

Does switching modes also record cyclic stick positions (hence the instruction to center sticks BEFORE switching modes) or does it assume some center position? If so, any movement from recorded position would be interpreted as a command to move the helicopter. If you program failsafe to switch to Atti/GPS mode, your sticks would be in a random position depending on what you were doing, with Naza memorizing that position. Then the fail safe position of center stick would put the heli in an unstable path. I'd test but waiting on parts to get the Bergen in the air.

[Tahoe Ed]

I am there with Chris. In Manual, loss of signal, you crash. I have multiple FBL controllers that will do the same. I am trying to figure out if I can use my JR receiver to go set up a preset failsafe that will will set the Naza to GPS on loss of signal.

[Titusx]

Originally Posted by Tahoe Ed

I am there with Chris. In Manual, loss of signal, you crash. I have multiple FBL controllers that will do the same. I am trying to figure out if I can use my JR receiver to go set up a preset failsafe that will will set the Naza to GPS on loss of signal.

For setup any different stick position than center and throttle cut on JR receivers, you just have to power the Rx with the bind plug, remove it, and then turn on the Tx with the stick in the position you want to be recorded.

[nightflyr]

Hope this helps....
Seeing how both fail safes operate
I would presume you would use the Preset Fail Safe option.


The R921 features two types of fail safe: Smart Safe™ and Preset Fail safe
R921 Binding Instructions
The R921 receiver must be bound to the transmitter before it will operate. Binding is the process of teaching the receiver the specific code of the transmitter or transmitter module so it will connect only to that specific transmitter. Once bound, the receiver will only connect to that specific transmitter (module) or when used with a Spektrum™ or JR® transmitter that has Model Match™, the receiver will only connect when the previously bound model memory is selected. If another model memory is selected, the receiver will not connect. This feature is called Model Match and prevents flying a model using the wrong model memory.
Quick Connect
In the event of a power interruption, the receiver will reconnect with the transmitter immediately when power is restored. This feature helps avoid control loss during short interruptions in power. NOTE: If a power loss occurs, the LEDs on the main receiver and remote receiver rapidly flash indicating a power loss has occurred. If this happens, it is strongly suggested that the cause be determined and corrected before further flying.
Note: The R921 features DSM2™ technology and is compatible with all Spektrum and JR DSM2 aircraft transmitters. The R921 is not compatible with the DX6 first-generation DSM® park fl yer system.
BIND PLUG
Preset Fail safe
Preset Fail safe is ideal for sailplanes and is preferred by some modelers for their glow- and gas-powered aircraft. With Preset Fail safe, if the signal is lost all channels are driven to their preset fail safe positions. Here’s how Preset Fail safe works:
Receiver power only
When the receiver only is turned on (no transmitter signal is present), all servos except for throttle are driven to their preset fail safe positions, normally control surfaces at neutral and the landing gear down. These fail safe positions are stored in the receiver during binding. At this time the throttle channel has no output, to avoid operating or arming the electronic speed control. In glow-powered models, the throttle servo has no input signal so it remains in its current position.
After connection
When the transmitter is turned on and after the receiver connects to the transmitter, normal control of all channels occurs. After the system makes a connection, if loss of signal occurs Preset Fail safe drives all servos to their preset fail safe positions that were set during binding.
For sailplanes, it’s recommended that the spoilers/flaps deploy to de-thermalize the aircraft, preventing a flyaway. Some powered modelers prefer to use this fail safe system to program a slight turn and low throttle to prevent their aircraft from flying away. When the signal is regained, the system immediately (less than 4ms) regains control.
Preset Fail safe:
• Prevents unintentional electric motor response on start-up.
• Eliminates the possibility of over-driving servos on start-up by storing preset fail safe positions.
• Establishes preset fail safe servo positions for all channels if the signal is lost.
Note: Fail safe positions are stored via the stick and switch posit


Smart Safe Fail safe
Smart Safe is ideal for most types of electric aircraft and is also recommended for most types of gas- and glow-powered models. With Smart Safe, when signal is lost the throttle channel only is driven to its preset fail safe position (normally low throttle) while all other channels hold last command. Here’s how Smart Safe works:
Receiver power only
When the receiver only is turned on (no transmitter signal is present), all servos except for throttle are driven to their preset fail safe positions, normally control surfaces at neutral and the landing gear down. These fail safe positions are stored in the receiver during binding. At this time the throttle channel has no output, to avoid operating or arming the electronic speed control. In glow-powered models, the throttle servo has no input signal so it remains in its current position.
After connection
When the transmitter is turned on and after the receiver connects to the transmitter, normal control of all channels occurs. After the system makes a connection, if loss of signal occurs Smart Safe drives the throttle servo only to its preset fail safe position (low throttle) that was set during binding. All other channels hold their last commanded position. When the signal is regained, the system immediately (less than 4ms) regains control.
Smart Safe:
• Prevents unintentional electric motor response on start-up.
• Eliminates the possibility of over-driving servos on start-up by storing preset failsafe
positions.
• Establishes low-throttle fail safe and maintains last-commanded control surface position
if the RF signal is lost. Note: Fail safe positions are stored via the stick and switch positions on the transmitter during binding.

Note: Failsafe positions are stored via the stick and switch positions.

[R_Lefebvre]

That's why I love my FrSky equipment. They give you an actual button instead of a binding plug. Boot up, put the sticks in the position you want, press the button, preset stored. Done.

You can even use a different method where you can push a button on the Tx module while flying to store it. But that requires a firmware change.

[zeeflyboy]

Yeah same with EzUHF - power up the Rx and Tx, put everything in the position you want and then just push the bind/failsafe button. Job done.

I like simple!