Computer Controller Question

[bbarn]

Can we use a computer to control the flap on our streamliner (NACA 66 Special - A/BGS) to adjust down force or must it be a manual process? Specifically we are looking for an interpretation of rule 2.Q.

[Stainless1]

Wouldn't it be better to use the computer to collect downforce data and manually adjust as speed and traction require. 

I would expect you would need 3 computers dedicated to flap control if you went that way.  A primary, a secondary and one to ensure they were in agreement prior to moving the surface.  If you don't think it is necessary, maybe a little overkill, check into fly by wire airplanes.  You might want to do a little analysis into worse case malfunctions, oscillations, how to control and filter them.

[robfrey]

Already did the worst case scenario malfunction. We are fine. We have a couple of fail safes built in. Wing can never make lift as hard stops will stop the flap from going negative. Also flap will start off with high angle and decrease as speed increases. As flap loses angle of attack, a resettable ratcheting system will keep it from regaining angle and overloading the tires.

[Dean Los Angeles]

2.Q Computer
Vehicles may be equipped with a computer which affects engine operations ONLY.

You could argue that the wing changes the load on the tires and is part of your engine traction control system.

Or skip the computer and build an electronic control.

[bbarn]

2.Q Computer
Vehicles may be equipped with a computer which affects engine operations ONLY.

You could argue that the wing changes the load on the tires and is part of your engine traction control system.

Or skip the computer and build an electronic control.

That's why we are askiing the question, we'd like to know for sure before we execute a plan. There are a few different ways to accomplish the task, we just want to make sure the one that is picked is legal.

[NathanStewart]

2.Q seems pretty black and white to me.

[Stainless1]

Wow, does that mean when I carried a laptop in the car to be a data logger it was illeagal?  Guess I better look harder at the book 

[4-barrel Mike]

And make sure that you've stripped the ABS out of your production vehicle!

Mike

[Jack Gifford]

2.Q seems pretty black and white to me...

No. It's a poor rule. I spent my whole career in electronics- the final couple of decades in software engineering. The term "computer" is too ambiguous in this context.

[Peter Jack]

Data logging doesn't affect the operation of the engine. it just records what happens so that a revised tune up can be applied.

Pete

[RansomT]

And make sure that you've stripped the ABS out of your production vehicle!

Mike

WOW!  any newer production vehicle has a computer controlled transmission if it is an automatic.

[SPARKY]

Several years back I "explored" the idea of a spoiler plate that changed angles underway, based on the feedback I got--my conclusion was that if I changed the plate with air cyls. whose controls were actuated by gear shift lever POSITION changes---I would not violate "the spirit" of the rules in place at that time.

[NathanStewart]

Wow, does that mean when I carried a laptop in the car to be a data logger it was illeagal?  Guess I better look harder at the book 

Stainless, see the next rule down from 2.Q: 2.R Data Recorders. 

No. It's a poor rule. I spent my whole career in electronics- the final couple of decades in software engineering. The term "computer" is too ambiguous in this context.

I'll admit that the verbiage is antiquated but the intent of the rule is still inherent and fine.  I don't think computer controlled active aero is allowed.... or at least that's what I'm taking from this rule.  If computer controller active aero is allowed, bbarn will need to get verification from the rules committee.  Obviously the association allows computerized trans control and I've personally yet to see a race vehicle show up with ABS but have never heard of anyone having to remove their ABS controller so perhaps the rule needs some "word-smithing" but I'm not aware of anyone having previously used a "computer" to control their aero package.  Whether that's because no one's tried to do it before or because it's illegal, I don't know.  Again, maybe someone has used computer controlled active aero.... I'm just not aware of it.

A conversation has begun about better and more current definitions and descriptions for all this "computer" and "EFI" stuff (mainly as it pertains to the vintage category but it will probably pour over to other things as well).  This is why we have the rule change procedure that we do.  If you're an SCTA member and you don't like how a rule is written (or want to introduce a new rule or whatever) then you get the opportunity each year to propose a rule change.  If computer controlled active aero isn't currently allowed (maybe it is, I don't know) and someone thinks it should be then by all means submit a rule change proposal.  Or you can just argue about it here.   
 

[Glen]

Art Arfons jet car had a linkage controlled wing connected to the suspension that changed the wing angle with any lift.

[NathanStewart]

Several years back I "explored" the idea of a spoiler plate that changed angles underway, based on the feedback I got--my conclusion was that if I changed the plate with air cyls. whose controls were actuated by gear shift lever POSITION changes---I would not violate "the spirit" of the rules in place at that time.

Bill, the Joe Law lakester used a mechanically controlled wing much in the way you've described and it was completely legal.