clutch by wire system

[anshul vohra]

hi i am in first year of eee. can anyone tell me the basics of the clutch by wire systems. or redirect me to a link where it can be found. thanks

[jaca]

yes, you attach one end of the wire to the clutch linkage on the transmission, and pull on the other end of the wire to engage/disengage the clutch

seriously though, this is a pretty complicated topic

I know there are a few teams out there that run an automated clutch, and most look like they're running pneumatic actuators, which are light and have the required power and precision

the big issue is the control logic - I haven't implemented anything like this, but my first thought would be to run a manual clutch and log the displacement and force exerted on the linkage during driving with a linear pot and a load cell - this should give you a good starting point for the automated model

one thing to consider is that you cannot run a throttle actuator, so the benefits of clutch by wire are greatly reduced when you have to manually blip the throttle on downshifts.. in this situation it would be easier to coordinate if the driver is controlling both clutch and throttle

[exFSAE]

I like pneumatic clutches myself, on these cars. The current required on an electronic actuator to hold the clutch disengaged might be high. Maybe not though.

Pneumatic system you can hook a small needle valve to the "blow off" end of the actuating cylinder so you can tune how quickly the clutch engages for launches, etc.

[Mikey Antonakakis]

Hey, it's Jake!

Yeah, I'm gonna agree with you, Jake. If you still have to blip the throttle on a downshift, I don't really see much benefit. It might actually be trickier, because you don't have complete control over the clutch, so you have to be very precise with your blips. I'm not speaking from experience though.

[murpia]

Originally posted by jaca:
one thing to consider is that you cannot run a throttle actuator, so the benefits of clutch by wire are greatly reduced when you have to manually blip the throttle on downshifts..
Are all forms of throttle actuator banned? An idle-valve or a partial authority 'blipper' would not represent a serious safety issue.

Regards, Ian

[overdrive535]

http://www.formulasae.org/forums/formula/dispatch.cgi/r...20Traction%20Control (http://www.formulasae.org/forums/formula/dispatch.cgi/rules/docProfile/100226/d20081029210251/No/B.8.5.2%20TB%20for%20Traction%20Control)

food for thought

[Mikey Antonakakis]

Originally posted by murpia:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jaca:
one thing to consider is that you cannot run a throttle actuator, so the benefits of clutch by wire are greatly reduced when you have to manually blip the throttle on downshifts..
Are all forms of throttle actuator banned? An idle-valve or a partial authority 'blipper' would not represent a serious safety issue.

Regards, Ian </div></BLOCKQUOTE>
That's what I'm hoping for http://fsae.com/groupee_common/emoticons/icon_smile.gif

[jaca]

That's interesting.. I guess the idea would be to go wot during downshifts, tapering off with the second tb to maintain steady state throttle overall, blip with the 2tb, then maybe blend back in to steady state as the driver rolls off after the downshift

pretty slick, fairly complicated from a controls standpoint though, lots of variables

Or if you wanted to be tricky, have a hand throttle for the main tb and run the real throttle drive by wire. Something tells me that might violate intent http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[murpia]

After a quick read of the rule book, there appears to be no mention of idle speed control valves or 'blippers' either to say they are OK or to say they're banned.

In my assessment, they are clearly NOT drive by wire electronic throttle control. But I advise any team considering them to get a rules clarification...

When used in other forms of motorsport, a blipper is subject to safety rules that cut the engine if it sticks open. These are implemented by the controlling ECU.

Regards, Ian

[jaca]

as far as I understand it, the throttle may not be electronically actuated in any way

according to the rules clarification posted above, you can run an additional sequential throttle that may be electronically controlled, as long as it's done in a way that doesn't violate intent

[Tech Guy]

Someone really ought to read the FAQ’s on the SAE web site.

You will find your answer at:
http://www.formulasae.org/foru...00066/10/def/9978929 (http://www.formulasae.org/forums/formula/dispatch.cgi/rules/folderFrame/100066/10/def/9978929)

[murpia]

Originally posted by Tech Guy:
Someone really ought to read the FAQ’s on the SAE web site.

You will find your answer at:
http://www.formulasae.org/foru...00066/10/def/9978929 (http://www.formulasae.org/forums/formula/dispatch.cgi/rules/folderFrame/100066/10/def/9978929)
Hey, FSAE is just like F1!

You have a rule book, plus a series of 'clarifications' when the published rules miss an essential detail or contain a grey area... http://fsae.com/groupee_common/emoticons/icon_smile.gif

Regards, Ian