Return to Home Failsafe

[eturn23]

I installed the Naza GPS module on my FlameWheel F450 today. After calibrating it, I tested out the RTH feature and had the following experience: after hovering the quad about 6 ft off the ground and about 15' from the launch position, I activated the Go Home Landing failsafe. The copter rose to about 60', which I was expecting, and then it started circling the home position area. It circled about 3-4 times but it didn't look like it was descending so I switched it back to GPS Attitude mode and landed it manually.

On the second test flight, I flew the FW about 40 yards away from the launch site and turned on the failsafe. This time the quad flew to within a 3-4 feet of the home position and hovered about a foot off the ground. When it tried to land, it hopped once, and one of its legs got caught in the grass so it flipped over.

Tomorrow I am going to test the RTH feature again. I think on the first flight I didn't wait long enough for the home position to be locked by the GPS even though I didn't take off until I got a blinking green light on the VU. On both test flights I didn't turn the Tx off, but I think I will try that tomorrow.

If anyone has any comments or ideas about what happened on my tests today I would appreciate any feedback and suggestions for improving my setup.


Here is what I am flying:

FlameWheel F450
Naza V1 with 3.14 firmware
DJI 30A ESCs
RCTiger 770kv motors
APC 10 x 4.7 props
DJI Naza GPS module
V2 PMU

4500 mAh / 4S / 14.8v / 30C batteries

Spektrum DX8 radio
Spektrum AR8000 Rx with Telemetry

Flight Modes: GPS, Attitude, RTH failsafe
No IOC
Gains: 120, 120, 120, 120, 80, 80

 

[Carapau]

On both test flights I didn't turn the Tx off

Nor should you EVER do this in my opinion.

Firstly the biggest point about flying is safety. Full stop/period.

So, why intentionally degrade the system by completely breaking the control link? Yes there is a strong chance that you will re-build the link when you turn things on but you are now also opening up the chances of things going awry. This is just not good airmanship. Its a bit like a 747 pilot shutting down 2 of its 4 engines with passengers on board just to check that it can still fly in such a state. Funnily enough you wont find many pilots doing this deliberately. Also, you will gain nothing in terms of testing by doing this, there just is no point. Read and re-read the manual until you know it backwards and then you will better understand the system eg the distances at which RTH and home lock work at properly (also take into account GPS accuracy). DJI auto-lands can often end in the aircraft touching down a couple of times before settling as it has to somehow work out where the ground is. Remember, the whole point of RTH is to bring an errant aircraft back into a safe area. If it can land in one piece that is a bonus. If it lands with a small crash, that doesn't really matter as it should not have put anyone / anything in danger if you consider your cordon distance around the home point take off and landing area.

From what you have written above, there is absolutely nothing wrong with your system. It is working as it should.

 

[RobertsUp]

I agree with Carapau that your craft seems to be working okay.

Last Sunday I tested RTH on my new quad 4 times and it worked beautifully. I initiated RTH when the quad was 300 ft. away. Difference is that my craft didn't pause to hover before touching down. It landed directly and gently and there was no hop after touching the ground. All 4 times.

I'm wondering if my vertical gains controlled the lack of hopping. My vertical gains are set higher. Maybe 110%. Don't know. It's something to experiment with.

 

[eturn23]

I tested the RTH failsafe feature again this morning and everything is working fine. I waited longer for the GPS to acquire the satellite signals and had no trouble getting the copter to Go Home and Land when I flipped the flight mode into Failsafe.

I also tested what would happen if my Tx and Rx lost their connection. I was in a large open park with no one else around and hovered the quad about 18" off the ground. When I turned the Tx off I was expecting the copter to rise up to 60', Return to Home and Land, but instead the motors just shut off and the quad landed.

I thought there was a way to setup a failsafe that would tell the copter to RTH and Land if the signal between the Tx and Rx was lost? Does anyone know how to set that up?


Carapau- your message on safety is well received. I always make safety my number one priority. I conducted my tests at a place and time where no one or nothing else could have been harmed or was at risk.

 

[BC-deGraaf]

You need to program the fail safe into your receiver. And i also advise to program a switch on your TX for RTH(failsafe) so that you always can switch back to manual! And regain control if something happpens.

 

[RobertsUp]

Your AR8000 receiver has to be set up in a specific way for automatic failsafe to work the way you want.

This link might be of help: http://www.rcgroups.com/forums/showthread.php?t=1789552 Scroll down a bit.

The receiver itself signals Naza to go into failsafe when it senses communication is lost.

It involves an additional powering up, off and a certain point at which to insert or remove the bind plug. You don't have to test it while flying. If your receiver failsafe is working Naza Assistant will light the failsafe box blue when you turn the tx off.