RunRyder RC Helicopter Topic - Robbe Heli Command.

RR Rated M For Mature

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 653 ONLINE 18 EVENTS SEARCH REGISTER START HERE

30 pages [ << < 27 28 ( 29 ) 30 NEXT >> ]

59674 views

TOPIC CLOSED

HeliProz	.	Ron’s HeliProz South	.	MTA Hobbies
	.		.

Aerial Photography and Video > Robbe Heli Command.

GeorgeM
Senior Heliman
Location: Europe

My Posts This: Topic Forum

Hi Gary,

Nice and informative post. Glad it works for you on your Trex.
Comparable to a Lama, by all means, is a very good measure of stability.

How different does it get when you are out of position hold and into horizontal ?

03-22-2007 10:41 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE

lele
Veteran
Location: italy

My Posts This: Topic Forum

Harris

that is not a bad idea

having a carvec at the price of a HC.
Apart jokes, I was thinking of something very simple no more than what the HC is right now with a little add of some mixed signal from GPS to keep the hover position in a some meters radius. I think that in terms of the cost of added electronics it should be few euros and a company could sell it for some hundreds more.
lele

03-22-2007 10:47 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE GALLERY

Gary Evans
Heliman
Location: Mesa, Az, USA

My Posts This: Topic Forum

Helicommand

GeorgeM

I usually lift off and switch right away to idle up which puts the HC into horizontal mode with my set up. Horizontal mode, at least at low level, is very stable. I have not done much flying at higher altitudes or FF so I'm not going to speculate. My guess is that the HC will help at altitude but you will still need to be flying the heli.

03-22-2007 11:25 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

GeorgeM
Senior Heliman
Location: Europe

My Posts This: Topic Forum

Gary, Thanks for your insight.

03-23-2007 06:36 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE

Harris
Senior Heliman
Location: Cyprus

My Posts This: Topic Forum

Has anyone experimented with the various stabilisation settings of the HeliCommand?

That's my next task! And also try the HC on my Freya Evo.

03-23-2007 06:49 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE GALLERY

Angelos
Key Veteran
Location: nr Oxford, OX11, UK

My Posts This: Topic Forum

Quote
...but it could be easier to get this by a IR stabilizer that would be able to make a simple elaboration of a GPS signal to stay in position an altitude. Is it possible that nobody comes out with such a device?

I have thought of this and tried to come up with various solutions but it is not as simple as you think. Modern GPS devices provide 5 to 10Hz updates and better than 1 foot resolution (I am talking resolution, not absolute accuracy). This seems sufficient to keep the heli within a small circle but… Lets say the helicopter is in position B and you want to be in position A. Using the GPS data we calculate that we need for move for example 5 feet at a direction 30 deg from North. What cyclic input do you need to apply?

-Angelos

Spartan RC R&D - Visit us at our local club www.helicollective.org.uk

03-23-2007 06:58 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

Gary Evans
Heliman
Location: Mesa, Az, USA

My Posts This: Topic Forum

Helicommand

Harris

I have thus far only worked on gain adjustments in position hold and horizontal mode. To adjust gain from the DX7 radio I'm using range adjustments for the 2-position switch (Aux2).
The HC factory default is 80% for both position and horizontal. I have the radio gain set to +76 for position and -150 for horizontal. Problem is that that doesn't tell me what actual gain the HC is using. I thought the software would show it but it doesn't. I've tried downloading the values with the radio both off and on in both position and horizontal but all it shows is the default 80%. I know I've changed the ranges because if I add any more in position it begins jerking.
Can you see gain changes in the software that you have made with radio adjustments?

03-23-2007 07:12 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

lele
Veteran
Location: italy

My Posts This: Topic Forum

Angelos

I am happy you got in to this discussion...
I was thinking of something like a closed loop keeping on reading the GPS position and manoeuvering in the opposite direction to fight drift.
The idea is that the heli is in position A and should remain in position A, would the 10hz data be enough to do this? The cyclic input would be something adjustable by some sort of gain that one could modify in relation of the speed of wind drifting the heli. any sense in this?
lele

03-23-2007 08:22 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE GALLERY

Angelos
Key Veteran
Location: nr Oxford, OX11, UK

My Posts This: Topic Forum

Lele,
We are talking about the same thing. Mine is just a more technical description. The onboard computer knows two things:

1. Where we want to be. Desired position (A)
2. Where we really are. Actual position (B)

From these two we find the error. The error may be just a few centimetres or maybe meters. But there will always be a small error. The error calculation tells us which direction we need to move to get to where we want to be (A). However this is in respect to the GPS co-ordinate system so the calculation will say… you have to move 1 meter Sount-East to get to A. And here is the problem… which way do you tilt the swashplate to make the helicopter move South-East? Do you tilt it forward? Right? Back?

If you prefer your description… which way do you tilt the swash plate to make the helicopter move in the opposite direction? What is the opposite direction in respect to the helicopter? Is it forward? Right? Back? I hope you are now beginning to see the problem.

-Angelos

Spartan RC R&D - Visit us at our local club www.helicollective.org.uk

03-23-2007 09:12 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

AceBird
Elite Veteran
Location: Utica, NY USA

My Posts This: Topic Forum

Quote
Using the GPS data we calculate that we need for move for example 5 feet at a direction 30 deg from North. What cyclic input do you need to apply?

Use two GPS signals one mounted in the nose of the heli and one in the tail for instance to determine what attitude the heli is to the earth. Then you will know which way to move the cyclic. I don't know how expensive this would be so it may not be realistic.

Ace
What could be more fun?

03-23-2007 09:32 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE GALLERY

kookboy
Key Veteran
Location: Vancouver, BC -up north and Seattle, WA down south

My Posts This: Topic Forum

Quote
If you prefer your description… which way do you tilt the swash plate to make the helicopter move in the opposite direction? What is the opposite direction in respect to the helicopter? Is it forward? Right? Back? I hope you are now beginning to see the problem. -Angelos

Maybe I'm a little off, but would some sort of compass incorporated into the system be able to tell which direction the heli is facing ?

This input would be able to then give direction to the swash program/movement .. 'if' facing North and the desired position is NW, then rotate heli to NW and swashplate movement (while facing NW) to get the heli to move from point B to point A.

1. Where we want to be. Desired position (A)
2. Where we really are. Actual position (B)
3. Which way the nose should be pointing (NW for example) (C)
4. Which way the nose is pointing (North for example) (D)

So the question is (B) Actual position and (D) Compass direction.

The answer is (A) Desired position and (C) desired pointing direction.

Is this possible ?

Just thinking out loud.
Jesse

... But honey it was only $$$

03-23-2007 09:38 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE GALLERY

Angelos
Key Veteran
Location: nr Oxford, OX11, UK

My Posts This: Topic Forum

Quote
Maybe I'm a little off, but would some sort of compass incorporated into the system be able to tell which direction the heli is facing ?

kookboy,
That’s exactly the answer I was expecting. And here is where the complications start. First the GPS North is not the same as the magnetic North, but this is easy to compensate for. The real problem is that the electronic compass is affected by the attitude of the helicopter. A few degrees pitch or roll will significantly affect the measured heading. It can be compensated but to do this we need to know the pitch and roll angles and to get these we need an IMU. So we are back to having all the components and complication of an inertial system.

What Ace has suggested is perhaps a possible solution as it remains unaffected by magnetic heading and the helicopter’s attitude. I was in fact discussing this method with someone on another forum less than two weeks away. However, it is still doubtful if this will work reasonably well since the heading estimation will be very coarse.

-Angelos

Spartan RC R&D - Visit us at our local club www.helicollective.org.uk

03-23-2007 09:57 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

GeorgeM
Senior Heliman
Location: Europe

My Posts This: Topic Forum

LOL... use a CSM 720 and the tail will stay put !!!

Angelos... you have also produced a gyro .. no ???

OK. Some seriousness. Having an IMU on board is no problem. Its welcome. They're not so expensive lately.

What to do with the data, is the real head scrathcher.

Angelos.. Frankly..
What do you think of what I proposed earlier ?
IE..
using IR to stabilize horizontally and then inserting lowpass filtered acceleration values ( that are already co-ordinated physically because they are aligned x-y wih the helicopter's X-Y axis) into the control link...

On paper, it should work .. shouldn't it ??
I know there's some compensation (tilt and acceleration itself) to be dealt with, but the major control loop governor here is the IR system.

What I am after, and perhaps many other "simple" Ap'ers, is a "pause" function in the manual flight envelope of their helicopter.
Perhaps, most see the waypoint manager and flight envelope controler as "expensive" extras. If you know what I mean !!

Sort of.. Mike's NRI latest youtube video found elsewhere in this forum, when hovering at the end of the flight. But constructed from simple ideas like mine mentioned earlier.

George

03-23-2007 10:08 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE

Angelos
Key Veteran
Location: nr Oxford, OX11, UK

My Posts This: Topic Forum

George,
The issue is not keeping the tail put; I could use the software of my own ds760 gyro for that. The issue is knowing what the absolute heading is in respect to north.
-Angelos

Spartan RC R&D - Visit us at our local club www.helicollective.org.uk

03-23-2007 10:13 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

GeorgeM
Senior Heliman
Location: Europe

My Posts This: Topic Forum

edited previous post

03-23-2007 10:29 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE

Harris
Senior Heliman
Location: Cyprus

My Posts This: Topic Forum

Quote
Helicommand Harris I have thus far only worked on gain adjustments in position hold and horizontal mode. To adjust gain from the DX7 radio I'm using range adjustments for the 2-position switch (Aux2).

Gary, I use a slider on my Futaba 9C to change gain from 0 to -100%. I don't use position mode so I don't use positive values.

Quote
The HC factory default is 80% for both position and horizontal.

This default is only if the "pilot" channel of the HC is not connected to the receiver.

Quote

I have the radio gain set to +76 for position and -150 for horizontal. Problem is that that doesn't tell me what actual gain the HC is using. I thought the software would show it but it doesn't. I've tried downloading the values with the radio both off and on in both position and horizontal but all it shows is the default 80%. I know I've changed the ranges because if I add any more in position it begins jerking.
Can you see gain changes in the software that you have made with radio adjustments?

I am not familiar with the DX7. On the 9C there is a servo monitor where you can see where each channel travel is set to. When your servo travel for the "pilot" channel is set to the middle, then your HC is set to 0%. If you change the setting of the pilot channel then positive values are for position mode and negative values are for horizontal mode. Typically +100% is the maximum gain in position mode and -100% for horizontal mode. See page 26-27 of the HC manual.

03-24-2007 11:40 AM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE GALLERY

AceBird
Elite Veteran
Location: Utica, NY USA

My Posts This: Topic Forum

Quote
However, it is still doubtful if this will work reasonably well since the heading estimation will be very coarse.

Is it possible if the feedback is fast enough to make a correction based on how the heli moved that would make up for a coarse heading?

Ace
What could be more fun?

03-24-2007 11:56 AM

PROFILE PM EMAIL POSTS BUDDY IGNORE GALLERY

Harris
Senior Heliman
Location: Cyprus

My Posts This: Topic Forum

Heli stabilisation

This is a very interesting discussion although a bit off topic!

My understanding is that in order to make a GPS signal work to move a heli from point A to B you need a means of knowing the heli's attitude. The only way to do this is to employ an AHRS (Attitude and Heading Reference System). A 3-axis magnetometer is only capable of providing the heading of the heli with respect to the magnetic North. It needs to have it's readings corrected for level flight, so it also needs the AHRS. In fact, good navigation systems integrate GPS, altitude, heading and attitude information all in one unit. See Crossbow Technology's microNAV for an example.

I don't think we are talking about this level of sophistication here. All we need is a system to keep the heli horizontal for a length of time while we are trying to get a picture or recover from dumb fingers!

For this purpose infrared works reasonably well but has several limitations mainly related to the presence of nearby trees or buildings. It also doesn't work very well when the ground is not flat or when the weather is very cloudy etc. The HC doesn't provide as good a stabilisation as infrared (at least for me!) but works unhindered by weather, buildings etc.

I hope a really clever guy (Angelos, JohnC, somebody else!) will come up with an inertial system that will provide the same quality of stabilisation with infrared but without it's limitations!

Harris

03-24-2007 12:02 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE GALLERY

Gary Evans
Heliman
Location: Mesa, Az, USA

My Posts This: Topic Forum

Helicommand

Quote
Harris This default is only if the "pilot" channel of the HC is not connected to the receiver.

You are correct but there is more than one gain setting in the software.

The pilot channel default is at the top of the page in my software version and the factory setting is 70%. That clearly is used only if the pilot channel isn't connected to the RX.

If however the pilot channel is connected to the RX then the radio can control gain if it has the necessary switch.

Then why -
Lower on the page both horizontal and position hold have separate gain settings and the factory settings is 8 for both. What function do these serve?

03-24-2007 04:29 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE

Harris

Senior Heliman - Location: Cyprus - My Posts This: Topic Forum

Quote
If however the pilot channel is connected to the RX then the radio can control gain if it has the necessary switch.

Or slider or volume pot.

Quote
Then why - Lower on the page both horizontal and position hold have separate gain settings and the factory settings is 8 for both. What function do these serve?

If you leave your mouse over each of those settings a small window will popup with a brief explanation:

Your guess is as good as mine!

I haven't played with any of them. That's exactly what I am planning to do next time I go flying. I just need to remember to bring my laptop...

03-24-2007 08:51 PM

PROFILE PM EMAIL POSTS BUDDY IGNORE HOMEPAGE GALLERY

30 pages [ << < 27 28 ( 29 ) 30 NEXT >> ]

59674 views

TOPIC CLOSED

Model Rectifier Corp	.	ReadyHeli	.	Power Helis
	.		.

Aerial Photography and Video > Robbe Heli Command.

Print TOPIC

Advertisers

Subscribe to This Topic