23 replies to this topic

[The Tiger]

Who in F1 are running automatic transmissions, how and why?

[Pioneer]

Who: Everyone as far as I know

How: They were already using electronically controlled Semi-Automatic transmissions, they simply let the computer "push the button" now instead of the monkey... um... I mean driver.

Why: Because they can

[BertlF]

AFAIK they use still the semiautomatic gearboxes. The shifting is actuated by the shifting paddles on the steering wheel (right side - up, left side - down), i think it's called a 'sequential gearbox' (the driver cannot miss a gear anymore. Left paddle - one gear down, right paddle - one gear up). The rpm's are indicated via LED panels on the upper part of the steering wheel (actually, it's not a 'wheel' anymore, it's a odd-shaped multi function device.....)

Bert

[Croaky]

ITV showed Fisichella doing a practise lap of Monza from the on-car camera, and he was definitely downshifting manually, but appeared to be letting the software do the upshifts. I wonder if it's something to do with downshifts upsetting the balance of the car, so he wants to know exactly when they'll happen.

[carlos.maza]

Hello all:

I just want to clarify something (please correct me if I'm wrong):
I thing nobody in F1 uses automatic transmissions, if we define an automatic transmission as a device carrying a torque converter, valves, etc.
They all have "conventional" gearboxes, in which gear shifting is electronically controlled. This is why they are called "Semi-Automatic transmissions".

It is my understanding that when the driver actuates on the shifting paddles on the steering wheel, the computer aboard automatically does the following sequence:
1-presses clutch
2-puts trans in neutral
3-releases clutch
4-accelerates to optimum RPM
5-presses clutch
6-engages gear
7-releases clutch

So it is not an automatic gearbox, it is "automated gearshifting". Am I right?


If I am right, I would like to ask you:
I understand how can a computer make the decision to up-shift (by an RPM limit), but how do you automate a down-shift?
Which parameters should be taken into account for a computer to decide it's time to down-shift? Braking?

Thanks
Carlos

[michaelab]

All the F1 transmissions are computer controlled manual transmissions. The computer and hydraulics control the action of the clutch and selecting the ratio. The decision when to change gear can be made by the computer (fully automatic mode) or by the driver using paddles behind the wheel (semi-automatic mode).

Similar (allthough less sophisticated) systems exist on a number of road cars (BMW M3 SMG, Ferrari 360 F1, Alfa 156 Selespeed etc).

All recent F1 systems have always had the ability to operate in fully automatic mode but teams were only allowed to use that mode since the ban on electronic driver aids was lifted at Barcelona this year. Most drivers are using fully automatic mode most of the time now allthough I believe they all have the option to override it if they want to.

The reason they use it is because it means the driver has another thing he doesn't have to think about and so can potentially be quicker. Also, the computer can optimise the shift points (down and up) so they are always done exactly at the optimum time for the given conditions and requirements. Say a driver needed to conserve fuel, the computer could be programmed to shift up 500rpms before the red line each time (which would be slower of course but that might not matter). Getting a driver to be that precise in those conditions is almost impossible.

To answer carlos.maza about downshifting: the computer will try to always match the revs of engine to the speed of the car so if the car is slowing down it will automatically change down. F1 systems though are very sophisticated and they can be programmed with different shift patterns to use on different circuits or even individual corners of a given circuit.

Michael.

[Crazy Canuck]

I’ve also heard that on some cars, the Williams in particular, you have the ability to program multiple gearshifts into one button. For example if you go into a 2nd gear chicane from a 5th gear straight you can push one button and the computer will drop the three gears for you all at once.

CC

[Ben]

The correct order, as detail in Peter Wright's new book is;

Upshift:

1 - flick paddle
2 - Ignition is ******** to unload the transmission
3 - The selector mechanism changes gear
4 - The ignition is returned to normal.

This doesn't allow complete sychronisation but this is managable unless it is very wet when the clutch may be slipped slightly to reduce any oscillation.

Automatic shifting simply replaces (1) with an automatic switching proceedure linked to the measured rpm of the engine (amongst other things I suspect).

Downshift:

1 - Flick paddle
2 - Drive-by-wire closes throttle and the clutch is disengaged
3 - If the downshift will cause an over-rev it is rejected, if not the gear is shifted.
4 - The throttle is blipped to synchronise the revs
5 - The clutch is re-engaged

No form of double declutching which Carlos describes occurs.

Ben
1-presses clutch
2-puts trans in neutral
3-releases clutch
4-accelerates to optimum RPM
5-presses clutch
6-engages gear
7-releases clutch

[jetsetjim]

In simple terms.. an F1 gearbox is a manual gearbox with software operated shifting mechanisms.

Most systems are hydraulically controlled, and work in a similar principle to a motorbike gearbox.. The gear selection is based on a sequential barrell operated system. Hydraulics, or pneumatics are used to rotate the barrell to change gear.

The driver changes gear using the two paddles on the steering wheel... one for upshift, one for downshift. It is possible with the software now for clutchless gearchanges to be carried out.. I'e flat-shifting. One common way of controlling the engine speed is to use spark cuts. In this case though, timing is critical..

As for downshifts, it is not uncommon for the clutch to be engaged and disengaged all in the space of 30-40 milliseconds. Again timing is critical, and most software systems will incorporate a "blip" on the throttle to ensure the engine revs are perfectly matched for the next gear.

As for multi-shifts..... this is very common in F1, and I would imagine every team runs it.. these will be programmed according to the relevant circuit, where there may be a lot of corners which are approaced in 5th gear, but taken in 2nd..... Therefore the software engineers program the gearshift mechanism to rapidly downshift from 5th to 2nd. A single button on the steering wheel is all that is needed to operate the system. It is a very simple procedure.

[michaelab]

Originally posted by jetsetjim
Most systems are hydraulically controlled, and work in a similar principle to a motorbike gearbox.. The gear selection is based on a sequential barrell operated system. Hydraulics, or pneumatics are used to rotate the barrell to change gear.

The driver changes gear using the two paddles on the steering wheel...

Firstly I don't think that F1 gearboxes are related to motorbike gearboxes. The main reason for saying this is that the gears don't have to be selected sequentially - it is possible to go straight from 5th to 2nd without going via the intermediate gears (4th and 3rd) - something which a motorbike type box would not allow.

They are conventional manual gearboxes (like on a road car) with selector levers and forks etc. The hydraulics do all the moving of the selectors of course though.

Secondly, the drivers don't use the paddles anymore (or very infrequently) - nearly all the changes (up and down) are initiated by the software now.

Michael.

[desmo]

Excepting the control strategies and implementation, F1 gearboxes are indeed very similar to a common motorcycle sequential gearbox. Electrohydraulically controlled non-sequential gearboxes were tried prior to the adoption of the current sequential units.

[jetsetjim]

Michealab..

I'm just basing my information on the 1998 spec gearboxes we currently run....

The driver can not choose any gear at any time..... A barrell selector is used, and gears have to be selected sequentially..

Incidentally, a selector Barrel is also used on an F3000 car, exactly the same principle as a motorbike.......

[Ben]

They all use barrel selectors. The skip shifts (5th to 2nd, etc) are just a control strategy where one control input results in the computer implementing more than one shift.

Ben

[michaelab]

Originally posted by jetsetjim
Michealab..

I'm just basing my information on the 1998 spec gearboxes we currently run....

The driver can not choose any gear at any time..... A barrell selector is used, and gears have to be selected sequentially..

Incidentally, a selector Barrel is also used on an F3000 car, exactly the same principle as a motorbike.......

What do you mean by "we run"? Are you involved in racing historic F1 cars?

I know that F3000 (and CART) use sequential barrel selectors like on a motorbike and it makes sense there because, given that you're not allowed a computer controlled gearbox, it's much easier to change gears using a sequential shifter that just goes up and down than messing about with slotting gears into a gate. However, I was sure that F1 boxes were not sequential. Oh well.

Michael.

[Ben]

Before the reintroduction of automatic shifting this year the gearbox had to be sequential to make the paddle shift simple enough, how else could a simple up or down mechanism work?

You do raise the interesting idea that with the new freedom in shifting strategies it might be benificial to have some form of automated h-pattern mechanism. I have mentioned on other threads that I feel the packaging problems this would cause preclude it. In the weight-obssessed world of F1 it is hard to beat a single actuator and the removal of a complex selector rail arrangement that the sequential barrel provides.

Ben

[mhferrari]

Formula One Teams use a manual transmission, that is semi-automatic or automatically controled.

[michaelab]

Originally posted by Ben
Before the reintroduction of automatic shifting this year the gearbox had to be sequential to make the paddle shift simple enough, how else could a simple up or down mechanism work?

The same way it works on the BMW M3 SMG and Ferrari 360 F1 road cars which have semi-automatic, computer controlled paddle-shift gearboxes but where the actual gearbox itself is identical to the 'normal' 6-speed manual box on cars without the semi-automatic option. The only difference is the hydraulics that move the selectors and the clutch (instead of the driver) and the computer software.

In fact, I believe that on one of these systems (BMW I think) if you flick the paddle twice very quickly it changes up (or down) 2 gears, skipping the in between gear. Also, if you let either of these systems operate in fully automatic mode (which they both have) they sometimes skip in between gears, especially when slowing down.

Just because the paddles mean that only sequential changes will ever be requested doesn't mean the gearbox has to be sequential.

Michael.

[Ben]

Your last paragraph entirely makes my point. What's the point of a sequential shifting mechanism with an actuting system that could be non-sequential but isn't operated as such? You need more than one actuator and it's heavier to much complex and not worth it with shifting times of 20 milleseconds or so.

Ben

[michaelab]

Well, I agree that in F1 there probably is no point but I was just answering your earlier question about "how could such a system work?". On road cars it is a definite cost saving to use a non-sequential box because it means they only have to develop one gearbox for both the manual and semi-auto cars.

Michael.

[The Tiger]

You mean to say that the current box the 360 uses is non-sequential. Then how does the paddle mechanism work?

[jpf]

Tiger - there are a series of electro-hydraulic actuators that move the selector forks the same way a shift lever would. As long as the computer knows what gear is currently selected and what the target gear is, it can run the proper sequence of lever movements to engage the right cog. No biggie.

And michael - your question overlooked one important thing: full auto control of gearboxes, and thus skip-shifts, were only allowed starting in Spain. I think the chances of any team, (even the ones with the big bucks) developing a completely new selection mechanism during the season are pretty low! Shift times are so low now anyway, with part of that time used to disengage/re-engage the clutch, that it's a lot easier to just whack through a couple gears sequentially anyway. And of course there are the weight and packaging issues that desmo mentioned.

[Ben]

The 360 paddle shift is sequential, to my knowledge it can't skip shift.

Ben

[jpf]

Ben-

I think the idea though is that that is a limitation written into the software control program, and not a limitation of the physical selection mechanism.

[The Tiger]

JPF.

Ok, thanks, I get the point, but then this araises another big question. What is the diference between a normal and sequential gearbox, and why are sequential better? Are they faster? More reliable?

Thanks.