2015 FSAE Rules

[Kevin Hayward]

From the Tobias' post it looks like there may be two sets of EV power limits. One for FSG and one for others. Why aren't these rules well and truly locked down by now?

We are looking at very late revisions to rules that teams are trying to design to right now. There are less than 10 months before the first comp these rules will be used in. I can't be the only one that thinks this is getting absolutely crazy. Australian cars built this year are already ineligible for 2015 if they are running aero (at least without large changes).

Something needs to change with the timing of these rules.

Kev

[MCoach]

Kevin, rules are not yet finalized and we're almost done with our chassis design up here....

[mech5496]

It seems like the FSAE EV rules commitee decided against different power limits on RWD/AWD; despite the fact that I agree with that decision I find it a bit contradictory, and I will explain myself. The whole aero rule debate and the subsequent rules change has occured as the RC wanted a "field equalizer"; rules that require the teams to carefully evaluate the use of aero from first principles, and taht would allow teams without it to be competitive (or at least that was the official reasoning). Till now, running aero (given that the team could allocate some resources) was a n-brainer. Same goes with 4wd in the EV class. If a team has the resources, 4wd is a no-brainer; it allows greater traction under combined acceleration, increased recuperation and (as the rules are now) virtually no cost penalty compared with teams that run a single motor. The lower power limit was supposed to act as an equalizer for all the above; eliminate the advantage in the acceleration event while 4wd's would still have some advantage over all other aspects, making teams to really prioritize and evaluate the drivetrain. Not implementing the proposed rule means a step back; not necessarily at the wrong direction, but back, and it is highly contradictory with the aero rule changes IMO. BTW is there any word on the EV voltage limit for the US competitions?

[Adam Farabaugh]

If there is going to be a voltage limit change for FSAE Electric the teams need to know. We are getting close to cutting a PO for our battery cells...

It's hard for me to imagine that they would introduce such a change so late (although from a vehicle design standpoint I would be happy) because it would really f*** with teams that are well underway with design. But after reading this whole thread I am not so sure...

[Kevin Hayward]

The rules are due for a release at the end of this month. I am wondering if there is any chance the changes can be delayed until the next set of rules. From the end of the month we are looking at only a bit over 8 months to the first US comp to run the rules. There is no chance for the Oz teams to redesign to suit for next year, unless they skip the Oz comp.

Holding these rules back until 2016 would make it a nice lead time for the rules, and get us away from late rule sets. With a little effort we could stay on the track of early warnings for rule changes (with final wording) This will provide enough time for the rules committee to get feedback on the precise wording of the rules, and field questions early.

...

I wonder whether these forums could be used as a bit of a working group. We could start a few topics on the particular rule changes and run through the implications. Between the people posting here there is a lot of accumulated knowledge and capability.

Kev

[Z]

ON A MORE POSITIVE NOTE.
==========================

Here are some positive suggestions for how the FSAE Rule Book could be improved.

First note that good Engineering documentation is COMPLETE and CONCISE.
* "Complete" means that ALL the major INTENTIONS that are desired of the project are clearly spelled out.
* "Concise" means that all the little details that MUST BE MET are included, but ONLY ONCE each.

Importantly, not every possible tiny little detail can be covered in a finite documentation package. But, by the same token, not every little detail needs to be covered. Knowing where to draw the line is a measure of Engineering competence.
~o0o~

DESIGN FREEDOM - Right at the top, the Rules have;
"A1.1.1 To give teams the maximum design flexibility and the freedom to express their creativity and imaginations there are very few restrictions on the overall vehicle design."

This is a clear statement of a "major intent" of the Rules.

Sadly, this Rule used to be at A1.1, but has since been demoted to a sub-clause. Over the years there have been too many restrictions put onto detailed parts of the car design, thus subverting this "big-picture" Rule.

This Rule should be reinstated to its position as one of the major guidelines for the rest of the Rules.

Many of the recently added minor Rules, most of which, frankly, border on being meaningless (see just some examples below), should be deleted.
~o0o~

AERODYNAMIC DEVICES - There is NO NEED for ANY of these detailed Rules. Especially not when it is realised, as should be obvious, that all of the car's bodywork, the wheels and tyres, and even the driver's head, have aero-forces acting on them, so are difficult to distinguish from "aerodynamic devices".

It would be much better to simply put some constraints on where, and where not, parts of the car can be. As Harry said earlier, the Rules could simply specify a "green zone" that the car must be within. (Note that a "red zone", that must NOT contain parts of the car, would also work, but would require more ink. The "red zone" would simply be the complement of the "green zone".)

In keeping with A1.1 above, the specification of the "green zone" should NOT be too restrictive. For example, the current Rules give no restriction to maximum wheelbase, yet no Team has yet built a 10 metre long car in an attempt to maximise downforce from a huge aero-undertray. The track layout puts the most effective constraints on such things, in this case by making very long wheelbase cars difficult to drive around the tighter corners.

As another example, it is the slaloms that keep wheel-track (width) dimensions low, giving no need to mandate a maximum width dimension. If there were no "green zone" Rules covering maximum width, then it is conceivable that a Team could build a narrow-track car, but then fit very wide wings, that, because they are also mounted high enough, do not knock over cones.

So, simply specify the "green zone" as being between two longitudinal-vertical planes that contact the outsides of the wheels/tyres, and that should be enough for an overall width constraint. The current "front and rear overhang" Rules, together with the performance advantage of short wheelbases, are also enough to constrain overall length.

Overall height of the car can similarly be constrained (eg. "maximum one metre high, EXCEPT for the MRH..."). However, this height dimension should be taken from a "floor-reference-plane" that amounts to the horizontal surface that the car (specifically, its chassis) would sit on if its wheels were removed. This removes any ambiguity regarding ride-height adjustments from the suspension.

I agree with Kevin's comments from some time ago, that the competition would be visually more interesting, and a better test of the "big-picture" thinking of the various Teams, if the cars were allowed to look like anything from go-karts to Le Mans roadsters, with F1 somewhere in the middle. At recent comps see the Chinese Xiamen team as a bit-too-complicated-go-kart, and Michigan-Mega-Aero as an almost-LM car. Now imagine a grid with both those boundaries pushed outwards, and also with everything possible inbetween...

This potentially greater range of car designs, and hence greater conceptual challenges to the students, comes from lesser restrictions in the Rules (ie. A1.1). The alternative direction is a "spec-series", like F1.
~o0o~

DRIVER VISIBILITY - It might be argued that freeing-up the Rules this way might result in Teams turning up with inadequate forward visibility. Well, they already do!

Attempts to lower the driver's CG via more reclined seats, combined with FRH Rules, and the FASHION of mounting front spring-dampers on top of the nose, means that many cars already have very poor forward visibility. But the current Rule covering this (ie. T4.7) really does nothing to prevent this.

The current requirement to have a "minimum field of vision" of 200 degrees in Azimuth is MEANINGLESS because it gives no similar specification in Elevation. So it is impossible to test this Rule (ie. "200 degrees Azimuth" at what height???), or even make sense of it. As should be obvious, the steering-wheel, FRH/foot-box/nose area, and the front-wheels, are always within, and thus obstructing, the driver's forward "200 degree field of vision" anyway!

This section of the Rules currently has the sentence,
"The driver must have adequate visibility to the front and sides of the car."
It would be enough to simply move that one sentence to an earlier section of the Rules that covers the "intent" of "safety" (see below), and then DELETE ALL THE REST of this section on "driver visibility".

Rather than unnecessarily complicating an already too long Rulebook, the Officials would better serve the students by pointing out that if the drivers cannot clearly see the track in front of them, then they are much more likely to knock over lots of cones, and thus lose lots of points. It is highly unlikely that a very poor visibility car will be a danger to anyone (think about it), and in the worst case such a car can be pulled off track for reckless driving.

Again, fewer Rules is better.
~o0o~

DRIVER EGRESS - This is another section of the Rules that has been mentioned in connection with the Aero-Rules. It has an entirely separate "intent" to aero, and the two different sections should NOT be conflated.

Specifically, there is currently nothing in the "driver egress" Rules that prevents, or even mentions, aluminium side-pods that might plastically deform in an accident, and thus intrude into the cockpit area, and trap the driver in an ensuing fireball. Bizarrely, the Rules taken as a whole seem to suggest that ONLY wing mounts could possibly trap the driver.

There is a long section at the top of the Rules about "intent...", which includes;
"A3.6 Violations on Intent
The violation of intent of a rule will be considered a violation of the rule itself.
A3.6.1 Questions about the intent or meaning of a rule may be addressed to ..."

There is far too much legalese there for my tastes, but the concept of "intent" is reasonable when covering possibilities that are difficult to accurately predict or specify. One such case is what happens in an "accident", since "accidents" come in many and varied forms.

A reasonable interpretation of the "intent" of the "driver egress" Rule is that the car should be constructed in such a way that the chances of the driver being trapped in the cockpit after an accident are LOW. It should be obvious that these chances can never be zero (eg. they might crash into some chain-link fencing, or lots of other possibilities...). Likewise, it is track layout that has the greatest influence in determining how bad any accidents might be, much more so than, say, wing-mounting systems.

IMO, the "driver egress" section should be put towards the top of the Rules under the general heading of "overall car design" or "safety". The Rule should simply express the intent that the car be designed with driver safety in mind, and specifically that the driver can quickly exit the car after most foreseeable accidents.
~o0o~

There are a lot of other sections of the Rules that would greatly benefit from severe pruning, or deletion. But to sum-up here.

* The Rules should COMPLETELY, and CLEARLY, state the overall "intentions" of the competition.
* The specific details that must be met to comply with above should be as CONCISE as possible.

This is a bit like a GOOD Team's approach to the whole FSAE project, and also a bit like the car that such a Team would build.

Of course, "good Teams" are only good ... when they have competent leadership...

Z

[mech5496]

Z, I have proposed a really simple test regrading driver visibility, that involves 3 cones and a measuring tape. Placing one cone ahead of a car at a certain distance, two side cones on either sides of the car at 200 degrees and certain distance again. Cones should be at a certain height and minimum requirement would be that at least the top of the cone should be visible. Easy to check, either by a scrutineer or by a camera placed on the side of Percy's head. On the other hand, whatever you stated about visibility is true, i.e. not direct danger and teams with "bad" visibility will be penalized by cones...

[theTTshark]

Z, I have proposed a really simple test regrading driver visibility, that involves 3 cones and a measuring tape. Placing one cone ahead of a car at a certain distance, two side cones on either sides of the car at 200 degrees and certain distance again. Cones should be at a certain height and minimum requirement would be that at least the top of the cone should be visible. Easy to check, either by a scrutineer or by a camera placed on the side of Percy's head. On the other hand, whatever you stated about visibility is true, i.e. not direct danger and teams with "bad" visibility will be penalized by cones...

Honestly even with a very reclined seat position, forward visibility isn't really all that bad, or even necessary. Very rarely are you ever looking straight ahead. Not to mention our visibility is already better than if we were building closed top vehicles. Not really a concern IMHO.

What we should be concerned about in FSAE is fire safety and heat management. It's the number 1 threat to drivers in FSAE by a large amount.

[stever95]

I am really agreeing with the things you're saying in this thread, Z.

I don't understand how the rulebook got so out of hand compared to the 80's and 90's rules I've read through. Which took all of 10 minutes.

[mdavis]

Z, I have proposed a really simple test regrading driver visibility, that involves 3 cones and a measuring tape. Placing one cone ahead of a car at a certain distance, two side cones on either sides of the car at 200 degrees and certain distance again. Cones should be at a certain height and minimum requirement would be that at least the top of the cone should be visible. Easy to check, either by a scrutineer or by a camera placed on the side of Percy's head. On the other hand, whatever you stated about visibility is true, i.e. not direct danger and teams with "bad" visibility will be penalized by cones...

The Shell Eco-Marathon has a decent visibility check. It's far from perfect (as it's reasonably easy to cheat if you get creative), but basically, you put the car in a certain spot, and put colored dots on the ground at some distance in front of and to the side of the car. The driver has to pick out the color of each dot on the ground. To adapt that to FS, putting the dots a certain height above the ground, changing them out for each car (have 3 dots to check, have 5-6 that the tech inspector can choose from) so nobody gains an advantage by watching the car in front of them. All of the drivers have to sit in the car for tech anyway (at some competitions anyway, that didn't happen at one big comp we went to in '13), so this shouldn't add much time to the tech inspection.

Honestly though, I'm with Trent on this one. Fire is a much bigger problem than forward visibility, even with a really reclined seat angle.

-Matt