Problem with NAZA-H

[R_Lefebvre]

Why does it seem it's the big guys who can't give us a $0.05 button?

[Titusx]

Originally Posted by R_Lefebvre

Why does it seem it's the big guys who can't give us a $0.05 button?

With JR as Nightflyer said, you have 3 different failsafe.
I really do not like bind buttons on Rx, or the posibility to change failsafe position only pressing a button. I prefer the plug, so there is no possibility that someone or myself change failsafe accidentally.

[R_Lefebvre]

I see you point.

Still on my Rx the bind button is very well shrouded and must be pushed with a small tool. Never had an accident yet.

[Ivor Hill]

+ 1 for the FrSky and the button. You need a pointed tool to get at the button. I have not done it for a while but if memory serves me right you need to hold the button down while powering up in order to bind.

[cbergen]

With a regular FBL controller, I would program my Rx to output center sticks, throttled up

And if you're inverted?

For as long as I've been flying, it's always been normal practice that in the event of a failsafe, the throttle goes to the OFF position.

This is a safety issue. A failsafe event means you have lost radio signal and you have no control of the aircraft. By ensuring the throttle is shutoff, you remove power from the rotors causing the aircraft to descend in as straight a downward movement as possible. Removing power from the rotors, while not a guarantee of any kind to preventing injuries, at least you won't have powered blades trying to slice into someone.

What we DON'T want is a powered aircraft, uncontrolled, going who knows where.... You state that you center your controls, what does that mean to a flying helicopter? It does NOT mean that the heli will go level and hover. It means that it will only continue in it's last trajectory, be it right side up, upside down, or sideways.

With the Naza H onboard, and controlling the aircraft (in attit or GPS mode), then if there is a failsafe event, the heli WILL go into a stable hover, until you either get control back or you run out of power (battery or gas), at which time it will descend straight down to the ground and be UNpowered, which again is FAR superior to a powered aircraft going who knows where.

Using the JR/Spektrum alternate method (Smartsafe) allows you to put the throttle to off AND turn off the Naza H if you want this to occur in a failsafe event.

[R_Lefebvre]

I see your point too. Still, I think a judgement needs to be made here.

If you expect that any signal loss will be temporary, throttled up and center stick will give you more of a chance of saving it. Keeping it away from the ground where people are.

If you expect it will be long, then I agree with your assessment.

I know center stick won't make it hover, but it will at least make it stop rotating, so you can maintain orientation if you can pick up the signal again.

[cbergen]

You can never predict what any signal loss will be, you should always plan for the worst case scenario.

This is hard experience learned from flying Gassers on 72 mhz. The typical interference came from the ignition system or from the drive train. By shutting OFF the engine, you removed the source of the interference and were able to perform an autorotation. If you simply went to idle or hold on the throttle, then you would NEVER come out of the interference.

A failsafe event can be caused by any number of issues, If you could predict what would cause that issue, I suggest that you correct that BEFORE you fly. If you 're like the rest of us normal humans without precognizant abilities, then shutting off the throttle for failsafe is the safest way to operate a helicopter.

[R_Lefebvre]

You don't need special powers to predict how long it will be. You can base it on past experience. I've never had a long lock-out. On 72MHz, or 2.4GHz.

And now I use a FC with really good failsafe so it doesn't matter so much.

[cbergen]

Apparently you've never seen a Gasser go into lockout during a long slow roll all the way to the ground...

Call me inexperienced and explain how you can predict how long a lockout is going to last. I'm sure MANY people would love to have that knowledge.

[Tahoe Ed]

Chris, nice to have you here.

[Aaron Hartwell]

Originally Posted by cbergen

And if you're inverted?

For as long as I've been flying, it's always been normal practice that in the event of a failsafe, the throttle goes to the OFF position.

When you didn't have anything on the heli capable of self-leveling or holding position I think it made sense to kill the motor. The heli was going to go down. It's almost always better to go in without power than with power.

Having a piece of technology on the heli that is capable of self-leveling and holding the heli in place changes the game a bit it'd say. It's not obvious that killing the power is the right thing for every situation or pilot.

I agree that the documentation should be more clear. The fact that a bunch of people on here are debating whether the behavior we're seeing is 'by-design' or a 'bug' makes it pretty obvious that the documentation isn't clear enough.

And I like it that we've figured out how to have the heli 1) kill the power for those who want that and 2) hover in place for those who think that's the right thing.

I'm sure we can all invent hypothetical situations where one approach would be better than the other. Seems sort of pointless.

Aaron

[Tahoe Ed]

Aaron, what modes are you talking about. All, ATTI, GPS?? Right now in ATTI and GPS the fail safe is set at hover. In manual it is throttle down and the copter is going down. What would you like to see?

[Aaron Hartwell]

Hey Tahoe,

I wasn't referring to any mode in particular. The thread seems to have evolved into a debate over what's the best failsafe with the primary sticking point being whether or not good failsafes should kill the motor or not. I was simpy pointing out that a) new technology like Naza changes the game so it's not a foregone conclusion that we should just do what we did in the past and b) with failsafes, there's no one-size-fits-all silver bullet that will handle all scenarios. The trick is to pick the one that best covers your personal flying style, environment, heli-setup, etc.

That was it really.

Aaron

[Tahoe Ed]

Aaron, I don't disagree with you. I like choices as well. I think that the Ace One RTH offers the best alternative. RTH then hover over the home position. That should not be a difficult algorithm for DJI to program. I would like to see a LOS trigger switch to ATTI or GPS/ATTI and then the RTH initiated. I asked the question from DJI if I could set up that scenario in my TX/RX for a preset failsafe. I have not heard back yet/

[Aaron Hartwell]

Tahoe, you described exactly what I'd like to have - RTH and then hover. I agree that it seems within reach given the hardware on the Naza H. Fingers crossed.

[R_Lefebvre]

Originally Posted by cbergen

Apparently you've never seen a Gasser go into lockout during a long slow roll all the way to the ground...

Call me inexperienced and explain how you can predict how long a lockout is going to last. I'm sure MANY people would love to have that knowledge.

You're right, I never have seen that, and I just told you how I predict how long a lockout is going to be: Statistics based on past experience.

In 20 years of flying, I have NEVER had a long lock-out. Not once. Maybe it's because I only use good radio equipment. Maybe it's because I build my machines very thoughtfully. Maybe it's because I only ever flew at a club field with frequency control back in the 72 MHz days. Maybe it's because I never used gas.

But that's the fact. I've only had short blips of low RSSI, which happens when you have short 2.4GHz antenna on the far side of a Carbon Fiber frame. If my motor shut down every time I had a blip, there'd be a lot more smoking craters at my field, and a lot more people on the ground put at risk.

So given that, why would I plan a system which is going to force a crash on a relatively common occurance? (short blips)

Frankly speaking, from a liability and morality standpoint, I'd have a real tough time putting into service a large, powerful heli, without a good failsafe system, now that the technology is available. And simply killing the motor is not a good system. If you're a DJI boy, Naza with the pre-programmed failsafe, or WK-H, Ace One, whatever. But I sure wouldn't fly anything that shuts down the motor and crashes because of a signal loss. Now that the technology exists, you're liable to get sued into oblivion if anything happens. Because it will be interpreted by the courts as carelessness and gross negligence.

That should not be a difficult algorithm for DJI to program.

You're right. It's fairly trivial. I've only been programming for 1 year. And I only do it part time. And I can do it. The only reason DJI does not offer this is because they don't want to. It's just that simple. Getting a heli to fly at 5 m/s towards a single waypoint is a joke. It doesn't get hard until 10+ m/s.

[cbergen]

Because YOU'VE never had a long lockout does not mean it doesn't happen. How wonderful that you are willing to take the risk of a machine flying who knows where, when we know for a fact it DOES happen. Talk about a liability!!

I am in agreement here that if technology allows us a better form of failsafe, then we certainly take advantage of it, just as failsafe's have improved with the advent of 2.4 and JR/Spektrum's Smartsafe and the ability to tell our aircraft what WE want to happen in the event of a signal loss.

IF the autopilot has the ability to bring the aircraft home, then I agree that is the best alternative vs simply shutting off the engine(s). If that is NOT a capability built into the system, meaning an autopilot with no GPS, then I suggest it is best that that the aircraft descend down as straight as possible with NO power being applied to the rotors.

Of course this would assume that you are flying with the safety in mind and NOT flying over people or structures. If you are guilty of that, then you ARE a liability and need to reassess your priorities.

A multirotor with 10-16" props can slice and dice just as nicely as any 700-800 class helicopter.

[R_Lefebvre]

This is turning into a pissing match. I agree, that if you use equipment that frequently experiences long ( >1 sec) periods of lock-out, that yes, it makes sense to kill the motor. But even better than that, is to simply stop using that equipment. Because if your system does shut down the motor, your helicopter is still going to crash somewhere. You may not be flying over people, but I'd bet that some of your customers do.

And here's why I'm pissed off about the DJI Naza-H:

If that is NOT a capability built into the system, meaning an autopilot with no GPS

The Naza is technically capable of an RTH. It has all the hardware required. And DJI understand the software side, because they've been doing it a long time in the Ace One, and the Wookong M and Naza-M does it, but the Naza-H does not. Why? In my opinion, it's just a question of money. And it's not because they don't want to spend the money to develop it. The code that does it in the Naza-M should work in the Naza-H. It's just a matter of compiling it in. In fact, if they do their coding as most companies do, Naza-M and H code compile from the same codebase, and they would have literally "turned off" the RTH part for the Naza-H build. I think they just decided not to include it so that they can retain their helicopter product structure with the Ace One at the top costing $1000's more.

Anyway, back to the original point, since my equipment does not lock-out for any significant period of time (autopilot or not), I would prefer to keep the motor running, so that I can save it when control comes back 1/2 second later, rather than have the motor shut-down, and then take 5 seconds to restart due to the soft-starter in my ESC.

If my equipment did suffer longer lock-outs, with enough frequency that I would be concerned about that, I would stop using it. Period.

[Valkman]

After all the reading I took the plunge I bought one from RCA. Hopefully I will have no issues. My plan is an AP rig and I will take the camera rig off to test fly first.
Thanks to all for all the info.

[jperkosk]

Originally Posted by cbergen

IF the autopilot has the ability to bring the aircraft home, then I agree that is the best alternative vs simply shutting off the engine(s). If that is NOT a capability built into the system, meaning an autopilot with no GPS, then I suggest it is best that that the aircraft descend down as straight as possible with NO power being applied to the rotors.

You might be a bit confused here, Chris. The sour grape is that Naza-H can only be set to GPS-locked hover as a ultimate form of signal-loss failsafe, while the Naza-M has a fully blown RTH, which seems to be withheld from -H version for the sole purpose of keeping up some marginal sales of their higher end controllers.

Still, GPS-locked hover will give you time to do something to reestablish the connection, you can't seriously think that killing the motor and letting your bird fall down is a safer option
I've seen once a guy at the club run like hell after his slow-flying runway plank and successfully reestablish the Tx link, think about the time window available for doing that when your aircraft is just sitting there frozen in one spot