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Old Mar 04, 2013, 06:49 PM
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Return to Home???? Really???

I've searched the group and see nothing of use so I'll start a new thread.

I have the OSD Pro, ET Stabilizaton for OSDPro, EagleEyes ground station and everything works well with the exception of the RTH.

I've setup the Safety/Servo Wizard and the control surfaces move in the correct direction along with throttle displayed value on the OSD. I checked this out using the flight sim in RTH test mode. If above 500 ft (set cruising alt) the throttle reduces to 0 and the plane returns home.

I've tried the RTH twice now and both times I've had the same results.

I turn off my 72mhz xmitter (I deem this the safest way to test RTH) and the senior telemaster maintains pitch and roll but doesn't seem to actually turn the plane back home. After about 15 seconds or so the plane does a violent roll to the left and I then switch my xmitter on and recover.

The throw value for T, Elv and Ail are -800/800 for all three controls. I reviewd my video and at the time when I turned off the xmitter the OSD displayed it's RTH display and during the violent turn the values for elv went to -1086 and the ail value went to -1408.

The above values are as you can tell outside the bounds of the -800 to 800 range. Why is this? Is the RTH going into turbo mode after X seconds if the plane doesn't turn? I've set up the gain settings for a gentle turn. Better slow and sure.

The EagleTree support message gives me the impression that "We (ET) can't get it to work and won't try to help you get yours working".

Does anyone in the group or possibly someone at ET have any ideas as to what I'm doing wrong? My gain and derivative values are close to the default values.

TIA

Fred

PS: Is there anyone in this group that has actually had the RTH feature work?
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Old Mar 05, 2013, 02:21 PM
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Hi Fred, sorry you're having an issue with RTH.

As a first step, could you please post a link to the video? That may help a lot. I think you are already displaying the Servo Deflections information, which will further help. If you could also attach your config file (.TXT) to this thread that will help also.

One other question: are you using a gain knob to control the Guardian stabilization gain on your radio, or are you using the default gain in the Guardian menu?

Re the support message, I'll have to review what that is saying (it should not be implying the above!).
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Old Mar 05, 2013, 02:22 PM
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Dont turn your TX off. if you have a computer radio, setup a switch to reduce the throttle to a negitive amount under your 0 stick position. set your failsafe with the switch engaged.

make sure to set the PCM/FS setting in the osd. re-run setup wizard.

move your throttle to 0 and then hold the switch you used for the offset/mix to reduce to a lower amount... RTH should engage.
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Old Mar 05, 2013, 04:48 PM
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Only problem is that the receiver doesn't have any kind of failsafe. :-)
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Old Mar 05, 2013, 05:20 PM
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I'm using the default gain since the receiver I have doesn't have enough channels for a gain switch. Right now I'm using a narrowband 72mhz radio and I'm thinking about switching to a 2.4 spectrum receiver so the gain control may very well be added in the near future.

I just attached the config file. It was just downloaded from the OSD so it's the exact config that was flown yesterday.

Here's the short Youtube link:
EagleTree RTH Test (0 min 31 sec)


The spiked Ele and Ail values are displayed at the 18s mark. They don't stay long because I'm pretty quick on the transmitter power switch! :-)

Looking forward to seeing what you think.

Thanks,

Fred
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Old Mar 06, 2013, 04:52 AM
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Joined Jan 2011
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Fred,

First We need to get it to turn.

In order to do that, I would first increase turn proportional gain.

Increase it by 10 points, and record your next flight, then post your results.

This could take a few flights to get it working perfectly, but once we get it to turn, then we can proceed.

-Mike

Quote:
Originally Posted by ftherrmann View Post
I'm using the default gain since the receiver I have doesn't have enough channels for a gain switch. Right now I'm using a narrowband 72mhz radio and I'm thinking about switching to a 2.4 spectrum receiver so the gain control may very well be added in the near future.

I just attached the config file. It was just downloaded from the OSD so it's the exact config that was flown yesterday.

Here's the short Youtube link: http://www.youtube.com/watch?v=HjH8jJFWk_k

The spiked Ele and Ail values are displayed at the 18s mark. They don't stay long because I'm pretty quick on the transmitter power switch! :-)

Looking forward to seeing what you think.

Thanks,

Fred
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Old Mar 06, 2013, 12:01 PM
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Mike,

I'm aware of the proportional gain control, but it does turn in the sim so I'd first like to hear from ET why the elv and ail outputs are spiking when it doesn't turn immediately.

Fred
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Old Mar 06, 2013, 01:16 PM
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Joined Aug 2004
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Fred,

m_beeson has some given some good advice.


LOTS of info here as well http://www.rcgroups.com/forums/showthread.php?t=924018 It is 346 pages long.

I did a search on RTH only and found 24 pages of hits.

Dan
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Old Mar 06, 2013, 04:22 PM
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Joined Jan 2011
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Fred,
First of all, your simulator will act differently than the plane in real life. There is no way to simulate everybodys diverse setups.

"Well, I guess it would be possible, but it is not the case"


Using my experiences; This is what I think Is happening.

Your plane is given the command to RTH, but your control surfaces have not been given permission to move sufficiently in order to actually make a turn.

The plane is trying to turn, but the permissions are not sufficient to do so.

As a result; Your plane travels in a straight line until the derivatives build up and then you have an error that It cannot ignore.

It tries to correct the error by giving the only command that it has been allowed to do, and that command is not a good command.

What we need to do is take it one step at a time, and fine tune it.

If you would like to proceed, then PM me.

-Mike

Quote:
Originally Posted by ftherrmann View Post
Mike,

I'm aware of the proportional gain control, but it does turn in the sim so I'd first like to hear from ET why the elv and ail outputs are spiking when it doesn't turn immediately.

Fred
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Old Mar 07, 2013, 04:26 PM
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Hi Fred,

Thanks for posting the video and config file. I looked at the config file and I don't see anything wrong.

Here is what I believe is happening:

1) RTH is working correctly.
2) Since you are using a PPM radio which has no glitch immunity and no failsafes, random noise pulses are typical when comms are lost. These can often be completely valid looking servo pulses, and the OSD cannot distinguish those to be the random pulses they are, if they stay valid long enough.

At 17 seconds into your video, notice that the RTH message goes away. That means the pulses coming from your reciever are valid looking to the OSD, and it's switching RTH off. And, these valid looking pulses are of course used to command the model.

One way to test this theory is to test RTH using the onscreen menus (if you are comfortable doing so) or reprogramming the OSD's control inputs to let you trigger RTH via the toggle switch. When RTH is triggered like that, there should not be random pulses coming in.

Ultimately, having a radio with failsafes is a good idea, though.

Let me know if this seems off base, or if I can help further.
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Old Mar 07, 2013, 11:53 PM
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Billpa,

Yes your right PPM radios are glitchy compared to DSM recievers and after todays successful RTH test using the PPM I am going to switch to a DSM receiver. The PPM receiver was not my problem. The problem I had was the relationship of the guardian stabilization and RTH settings of the OSD. After tweaking the values in both I was able to repeatedly do about a dozen successful RTH tests this afternoon.

Here is a link to a short 3 minute video showing the RTH working correctly:

2013-03-07 EagleTree RTH Test (2 min 41 sec)


I'd also like you to know that I would have been able to figure out this problem much more quickly had EagleTree given me just a little support.

Here's some EagleTree motto suggestions:

"Products engineered by engineers for engineers."

"Don't call us, we'll call you!"

"Don't have a degree in control theory,,, your problem, not ours!"

In conclusion: My recommendation to any non-engineer out there is to stay away from EagleTree unless your ready for a really long and hard heroic effort at trying to decode the EagleTree product instructions.

Sincerely,

Fred Herrmann
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Old Mar 08, 2013, 12:13 AM
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m_beeson's Avatar
United States, UT
Joined Jan 2011
3,405 Posts
march 4 (FIRST POST)

Quote:
Originally Posted by ftherrmann View Post
i've searched the group and see nothing of use so i'll start a new thread.

I have the osd pro, et stabilizaton for osdpro, eagleeyes ground station and everything works well with the exception of the rth.

I've setup the safety/servo wizard and the control surfaces move in the correct direction along with throttle displayed value on the osd. I checked this out using the flight sim in rth test mode. If above 500 ft (set cruising alt) the throttle reduces to 0 and the plane returns home.

I've tried the rth twice now and both times i've had the same results.

I turn off my 72mhz xmitter (i deem this the safest way to test rth) and the senior telemaster maintains pitch and roll but doesn't seem to actually turn the plane back home. After about 15 seconds or so the plane does a violent roll to the left and i then switch my xmitter on and recover.

The throw value for t, elv and ail are -800/800 for all three controls. I reviewd my video and at the time when i turned off the xmitter the osd displayed it's rth display and during the violent turn the values for elv went to -1086 and the ail value went to -1408.

The above values are as you can tell outside the bounds of the -800 to 800 range. Why is this? Is the rth going into turbo mode after x seconds if the plane doesn't turn? I've set up the gain settings for a gentle turn. Better slow and sure.

The eagletree support message gives me the impression that "we (et) can't get it to work and won't try to help you get yours working".

Does anyone in the group or possibly someone at et have any ideas as to what i'm doing wrong? My gain and derivative values are close to the default values.

Tia

fred

ps: Is there anyone in this group that has actually had the rth feature work?
march 5 (EAGLE TREE REPLY 1)

Quote:
Originally Posted by billpa View Post
hi fred, sorry you're having an issue with rth.

As a first step, could you please post a link to the video? That may help a lot. I think you are already displaying the servo deflections information, which will further help. If you could also attach your config file (.txt) to this thread that will help also.

One other question: Are you using a gain knob to control the guardian stabilization gain on your radio, or are you using the default gain in the guardian menu?

Re the support message, i'll have to review what that is saying (it should not be implying the above!).
march 7 (EAGLE TREE REPLY 2)

Quote:
Originally Posted by billpa View Post
hi fred,

thanks for posting the video and config file. I looked at the config file and i don't see anything wrong.

Here is what i believe is happening:

1) rth is working correctly.
2) since you are using a ppm radio which has no glitch immunity and no failsafes, random noise pulses are typical when comms are lost. These can often be completely valid looking servo pulses, and the osd cannot distinguish those to be the random pulses they are, if they stay valid long enough.

At 17 seconds into your video, notice that the rth message goes away. That means the pulses coming from your reciever are valid looking to the osd, and it's switching rth off. And, these valid looking pulses are of course used to command the model.

One way to test this theory is to test rth using the onscreen menus (if you are comfortable doing so) or reprogramming the osd's control inputs to let you trigger rth via the toggle switch. When rth is triggered like that, there should not be random pulses coming in.

Ultimately, having a radio with failsafes is a good idea, though.

Let me know if this seems off base, or if i can help further.


Quote:
Originally Posted by ftherrmann View Post
billpa,

yes your right ppm radios are glitchy compared to dsm recievers and after todays successful rth test using the ppm i am going to switch to a dsm receiver. The ppm receiver was not my problem. The problem i had was the relationship of the guardian stabilization and rth settings of the osd. After tweaking the values in both i was able to repeatedly do about a dozen successful rth tests this afternoon.

Here is a link to a short 3 minute video showing the rth working correctly:

http://www.youtube.com/watch?v=4xvehoe38ks

i'd also like you to know that i would have been able to figure out this problem much more quickly had eagletree given me just a little support.

Here's some eagletree motto suggestions:

"products engineered by engineers for engineers."

"don't call us, we'll call you!"

"don't have a degree in control theory,,, your problem, not ours!"

in conclusion: My recommendation to any non-engineer out there is to stay away from eagletree unless your ready for a really long and hard heroic effort at trying to decode the eagletree product instructions.

Sincerely,

fred herrmann
geze fred, i'd say he tried to help...


I'm just sayin...
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Old Mar 08, 2013, 12:20 AM
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Joined Jan 2011
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Fred,

One thing I know about Bill, is that he will be there for you when he can.

He is one of the most standup guys that I have dealt with.



I know that he is extremely busy right now, and he took the time to answer your questions, and give advise on your next step.

I want you to know that if you need further assistance, you can call on myself, or Bill, and others on the OSD threads. There is plenty of help out there.

-Mike
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Old Mar 08, 2013, 12:24 AM
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Joined Feb 2009
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M_beeson,

Yea sure! They don't answer the phone. They provide less than readable instructions. Over the course of 4 days EagleTree didn't answer the phone and basically told me via this thread that they were sorry I was having problems with RTH and that PPM radios are glitchy. That was a tremendous effort on their part and needless to say was "indispensible" in figuring out what the real problem was.

Give me a break! I'm just saying... You get better support from HobbyKing! That should tell you were EagleTree stands on supporting their customers!

Fred
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Old Mar 08, 2013, 12:27 AM
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Joined Jan 2011
3,405 Posts
Well,

I'm glad you got it worked out...
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