Fly-by-Wire model

[Kim Doherty]

First a word of explanation. It was brought to my attention that John Rist had used a similar system in one of his scale control-line models.

I asked the moderator to remove the original post.

My profound apologies to those who posted under a false pretense. It was never my intent to deceive anyone.

I have reviewed the posts made by John and can not see an appreciable difference. Thus I had no choice but to ask to have the original thread removed. I humbly apologize to all who thought we had accomplished a first. I will leave it to John Rist if he wants to claim that honour. So here is the modified post presented as what it is, a Fly-by-Wire stunt model.


On November 29, 2009 - Pat Mackenzie and I flew a true processor based "Fly-by-Wire" control line model airplane. There is no pushrod between the bellcrank and the elevator.

The model has dynamic throttle control and full fly-by-wire elevator with exponential. In the coming weeks we will activate the rudder and flaps with the same system. This will permit proper rudder usage in the overhead and "RABE" type rudder at other times. We will be able to have exponential on the flaps, differential flaps, exponential on the elevator and be able to mix flaps to elevator as suits the manoeuvre.

If you look very closely at the end of the longer video you will see the leadouts moving but not the elevator.

I have included two links to YouTube for you viewing pleasure and some pictures of the model. Note that the model would not have to be powered by electric to have the same control system.

I would like to thank Pat for the enormous amount of work he put into this project!! It could not have been done without him.


Enjoy!!   

Kim.

YouTube links:

[Alan Hahn]

Just one comment:
I enjoyed the original post and think it would have been better just to make the priority attribution as a correction--and not delete the whole thread--which now is gone.

Now I have to try and remember my smart-a$$ comments all over again!

Actually I still think one of the important details is that the Netzeband (hope I spelled it right this time) Wall is removed. You only need enough tension to turn the bellcrank/pot assembly, and not fight the aerodynamic loads on the flying surfaces. I think that i really significant.

[proparc]

My profound apologies to those who posted under a false pretense. It was never my intent to deceive anyone.
Kim.

Now that we know you are a dirty rotten scroundrel, and that your intent was to take down as many of us as you possibly could, when is the next post coming. This stuff was hot baby!!

[john e. holliday]

I think you are truely first with the fly by wire as John I beleive still uses a pushrod for the elevator to bellcrank hookup.  I think it is required in scale, but, don't take my word for it.  I know in carrier you must still control the elevator with the bellcrank to elevator pusrod. 

[Clancy Arnold]

Kim
I just reviewed the rules governing Control Line models and your system meets the rules.

Control Line General Rules - Page CLG-2

Paragraph 2. General.  A Control Line model is flown on one or more steel wire line(s) or metal line(s) of equivalent strength, attached to the model in a manner providing aerodynamic control of the model's elevation through manipulation of the control surfaces during flight.  Such manipulation of control surfaces, and any other of the model's operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety hazard to competitors or spectators.  The use of radio control to accomplish any control function on Control Line models is specifically prohibited.

Enjoy what you are doing and keep us all informed.
I just had to print that section in bold type.  Wonder why?

Clancy

[Peter Germann]

Dear Friends

Please allow me to remind you of the following invitation I have published on the F2B Group platform on Google on December 1st 2009:

QUOTE:

Dear Members of the F2B Group
As I have heard from Igor Burger today, Kim Doherty and Pat Mackenzie
have successfully flown a control line model where flight control
surfaces have been driven by servos. For details, please check the
related thread on the Stuka Stunt Forum.

Here is how the current FAI rule adresses the issue of flight control:

---------
Sporting Code Volume ABR, 2009 Edition, Sections 4A, 4B and 4C, page
60:
1.3.2 Category F2 - Control Line Circular Flight
This is a flight during which the model aircraft is manoeuvred by
control surfaces in attitude and altitude by the pilot on the ground
by means of one or more inextensible wires or cables directly
connected to the model aircraft. Devices in which the control wires or
cables are held in the hand or connected to a central pivot may be
used. No other means of controlling the model or the engine may be
employed during the takeoff and flight except that exercised by the
pilot through the line or lines.
----------


Please consider this message as an invitation to discuss the issue of
software assisted flight control in C/L in general or in F2B in
particular. I look forward to your comments and contributions.

Kind regards, Peter Germann

END OF QUOTE

I consider the issue as of great importance, well worth careful analysis of opportunities and consequences. Please contribute to the opinion building process within our community by expressing your point. Should you wish to follow and/or join the discussion within the F2B Group on Google go to:

http://groups.google.com/group/f2b-group?hl=en-GB

Topic name is: C/L Flight Control

Everybody is kindly invited to participate, just ask, on the Group page, for to be registered.

Best regards,

Peter Germann
F2B Working Group Coordinator
FAI F2 S/C Member

[Kim Doherty]

Dear Friends

Please allow me to remind you of the following invitation I have published on the F2B Group platform on Google on December 1st 2009:

QUOTE:

Dear Members of the F2B Group
As I have heard from Igor Burger today, Kim Doherty and Pat Mackenzie
have successfully flown a control line model where flight control
surfaces have been driven by servos. For details, please check the
related thread on the Stuka Stunt Forum.

Here is how the current FAI rule adresses the issue of flight control:

---------
Sporting Code Volume ABR, 2009 Edition, Sections 4A, 4B and 4C, page
60:
1.3.2 Category F2 - Control Line Circular Flight
This is a flight during which the model aircraft is manoeuvred by
control surfaces in attitude and altitude by the pilot on the ground
by means of one or more inextensible wires or cables directly
connected to the model aircraft. Devices in which the control wires or
cables are held in the hand or connected to a central pivot may be
used. No other means of controlling the model or the engine may be
employed during the takeoff and flight except that exercised by the
pilot through the line or lines.
----------


Please consider this message as an invitation to discuss the issue of
software assisted flight control in C/L in general or in F2B in
particular. I look forward to your comments and contributions.

Kind regards, Peter Germann

END OF QUOTE

I consider the issue as of great importance, well worth careful analysis of opportunities and consequences. Please contribute to the opinion building process within our community by expressing your point. Should you wish to follow and/or join the discussion within the F2B Group on Google go to:

http://groups.google.com/group/f2b-group?hl=en-GB

Topic name is: C/L Flight Control

Everybody is kindly invited to participate, just ask, on the Group page, for to be registered.

Best regards,

Peter Germann
F2B Working Group Coordinator
FAI F2 S/C Member

Peter,

Just to be clear, these were not your only words issued on Tuesday morning about this subject.

Here is Peter's response to a post by Bill Lee in reply to the above invitation.

Peter Germann said:

"Well, the point may be what has (or will in future be) been installed between the bellcrank motion sensor and the actuator deflecting the control surface. A simple wire? Or perhaps an intelligent signal processor of any kind? Such as adding the right amount of flap to compensate g-forces in manoeuvres? Or processing information from gyros, altimeters, high-res Galileo gps data or such?

I believe we have come to a point where me must decide in which direction to go; KISS or OPEN"


As I have expressed to Igor, just what great cosmic event are you worried about? and since it was clearly based on the flight of our model why did you not have the decency to first contact us directly? Further, I would think that as the leader of the F2B Group (of which I am a member) you would leave it to the group to decide if ANY decision is required with respect to this earth rattling event and if ANY direction need be taken and not try to influence the group with your beliefs.


Kim.

[Wayne Collier]

In my opinion, as soon as one introduces any software logic that varies the amount of control surface movement according to aerodynamic conditions so that the same amount of handle movement does not always produce the same amount of control surface deflection, you are no longer flying a controlline airplane.  True, control lines are still involved, but they no longer directly control the airplane.  If software enhances control, or prevents over control, there is a fundamental change in control dynamics so that what you are now doing is very different from direct mechanical control of the airplane.  I do not say this is bad or that it should not be done.  I do not think it should be passed of as a minor difference. I like motorcycles, but I would never assume I should be allowed to use one in a bicycle race. 

[Kim Doherty]

In my opinion, as soon as one introduces any software logic that varies the amount of control surface movement according to aerodynamic conditions so that the same amount of handle movement does not always produce the same amount of control surface deflection, you are no longer flying a controlline airplane.  True, control lines are still involved, but they no longer directly control the airplane.  If software enhances control, or prevents over control, there is a fundamental change in control dynamics so that what you are now doing is very different from direct mechanical control of the airplane.  I do not say this is bad or that it should not be done.  I do not think it should be passed of as a minor difference. I like motorcycles, but I would never assume I should be allowed to use one in a bicycle race. 

Wayne,

When I move my handle the elevator and flaps move the same amount every time. The only difference between my model and what we will call a regular model is that once back on the ground I can adjust the amount each moves, the amount each moves in relation the the handle input (exponential) and the amount each moves in relation to one another. Just as anyone can do by adjusting linkages on a regular model.

Kim.

[john e. holliday]

The AMA and FAI are tw3o different organizations.  Granted the AMA has to answer to the FAI when it comes to world competitions.  But, as Clancy has posted the new control system is legal according to the AMA rules.  Now the FAI if they stick by their rules means that the electric powered airplanes in aerobatics are illegal unless there is a rule Mr Germann has missed.  I remember when Windy could not fly his plane in the worlds or even the team trials with his control of the engine to shut down.  I haven't looked into the rules for scale, but, I think this new fly by wire will be a GOD send for scale modelers.  I hope Kim will continue on with their expeirments. 

[james dean]

Hi Kim,   

Warning: long ramble ahead. 

I've been following this thread with much interest and some fascination at the concept.  The only surprising thing to me is that it has taken so long for someone to give this a real go.  With the burgeoning battery and elec. motor/controller tech. coming out, it was just a matter of time getting to this stage in the development.

I applaud your spirit of adventure and ingenuity. This is another great step in moving the technology forward. (IMHO)  One can imagine what this concept would do for the beginner/intermediate or sport flyer.  A whole new section of the market could be about it's birthing just now.

Here's my caveat:

This just will not do for a serious contest contender moving up the ranks of stunt.  There has to be a line where a control line model ceases to be that and has become something else.  A cross over point of no return where the inherent challenge of the C/L stunt dynamic will have been lost when the trimming of a stunt model can be accomplished at some point by plugging in the CPU of your stunter and dialing in a set of paramiters to suit the weather conditions at hand.

(IMHO) A c/l stunter has to have a IC engine and a manually tunable control system (accomplished on the ground).

Personally, this is just what makes a c/l plane what it is for me. I love where the current state of design, materials, and building techniques have us at presant.

Going beyond where things are now materially may place the essential elements of c/l out of reach of the new person to this sport.  IE. ARFS/ARCS by way of building/finishing skills.  I hate to see c/l declining as a sport that a young crowd would want to pick up. But, that's how it goes.

I will hold on to what c/l means to me until there is no one to fly with and then pick up another hobby like boat building or photography.  Its just a personal choice and not meant to slight or be critical of you or your efforts.

But, if I had grand kids to show a good time and wanted to keep them entertained, I would buy one of these planes in a New York minute. (Were it available)  If I lived in an area where the snow comes early and stays long, it would be a kick to do some indoor flying just as you were doing in the testing vid.s.

Just a thought or two FWIW.

James Dean

[Wayne Collier]

Wayne,

When I move my handle the elevator and flaps move the same amount every time. The only difference between my model and what we will call a regular model is that once back on the ground I can adjust the amount each moves, the amount each moves in relation the the handle input (exponential) and the amount each moves in relation to one another. Just as anyone can do by adjusting linkages on a regular model.

Kim.

In that case, if I understand correctly, you would only be replacing mechanical adjustment with electronic adjustment.  Far less of a difference than I had imagined.  It kinda seems to put guys who are good with electronics more on a level feild with the guys who are good at tooling up special linkages and such.

[john e. holliday]

Hey James I would never try to build a boat when I can get one ready to go.  Where would golf, auto racing and snow skiing be if participants had to build their own equipment.  Forgot about all the other sports in the professional world.  By the way I do have and flown ARF/ARC's, but still build my own.

[james dean]

John,

I know what you say is so true.  I'm just saying from a personal stand point  the hobby in it's presant form is fine for me. It's a matter of choice.   I hope it's OK that I make that choice for my self? And not to limit other folks choice in doing so.

My purpose in posting was just to let people know my point of view not to change anyone else or criticise. FWIW

James Dean