19 replies to this topic

[mat1]

Good morning TNF-ers,

I have a question, or rather a field of interest, in which maybe some of you can help/enlighten.

Where can I find information about the so-called active cars of tje late 80s and early 90s.

I know Lotus started with experiments in this field, and I know it resulted in the glorious Willimas FW14 in which Mansell and Prost became rather easily champion.

But what exactly was active? How did it work? Did the cars still have conventionale spriings?

And: why was it that Williams could dominate so easily, i.e., why didn't the others, for example McLaren, catch up?

mat

[Darren Galpin]

The active cars of Lotus and Williams were not really active, but were reactive. They used gyroscopic sensors (maybe others as well) to detect the movement of the car at each corner, and then used hydraulic actuators to move the car up and down at each corner in order to keep the car level with the track. I believe that these systems completely removed springs and dampers, but I could be wrong.

[Frank de Jong]

IIRC most teams DID catch up in before or in 1993. I´m sure about Benetton, McLaren and Ferrari (remember the Gerhard Berger pit-exit), Arrows bought a complete McLaren system. In 1994, of course, it was banned from F1.

[david_martin]

Originally posted by mat1
And: why was it that Williams could dominate so easily, i.e., why didn't the others, for example McLaren, catch up?

McLaren certainly did catch up. The 1993 MP4-8 was every bit as advanced as the FW14/FW15 family were - possibly even more so in a couple of areas. Witness Senna scoring 5 wins with it - powered by a "customer" spec Cosworth HB V8, albiet with McLaren's own engine electronics. With a more competitive engine package Senna may well have won the 1993 championship in that car.

[MCH]

In addition to reactive suspension I remember Benetton having four wheel steering on their B193 in the last couple of races of 1993.

This was also banned for the 1994 season.

[Timekeeper]

The main idea of active suspension is to maintain constant ride height for the car and so retain the aerodynamic performance without degrading the driveability of the car.

The concept came about from a number of areas. There was the failure of the Lotus 80 in 1979 which Lotus hoped to solve with the twin chassis 88 in 1981 but this was banned. There was also the desire to improve the handling of passenger cars which Lotus was involved in. Citroen had of course had a suspension levelling system on their road cars for many years. At the beginning of 1983 Mansell raced an early version of the active system but it was soon set aside and Ligier also briefly used a Citroen derived system in the same year.

Lotus reintroduced it for the whole of 1987, winning 2 races but the system wasn't an unqualified success and they didn't use it in 1988. Williams used a simpler system with some success in several races in 1987. However they had a lot of problems with it during 1988 and it was removed during the British GP. That looked like it for active but Williams were working away at it and it returned with a vengence for the 1992 season.

As far as I understand it, Darren is basically right about the way it works but I'm not sure that active is an incorrect name. Isn't an ordinary suspension system reactive ie it reacts to a bump? The Lotus 99T did use springs as a backup in case the system failed.

[mat1]

Hmmm, I already heard a lot of interesting things.

1. was the system intergrated with brakes, steering, etc, or was it completely dependent on the sensors?
2. I didn't know Ligier did experiment with the Citroen-system. Was that including the hydropneumatic springs, or just the sensors and the software?

mat

[Timekeeper]

mat IIRC the Ligier system wasn't a full on active system like the Lotus ie computer controlled. But it still was a hydraulic system working to the same principle of maintaining optimum ride height.

There is an article in the 1987 Autocourse over several pages that charts the history of active to that point. Part of it says "Under the driver's seat, Lotus have mounted the systems computer. This receives a continuous flow of motion and driver control inputs, which are detected by a number of accelerometers, transducers and potentiometers sited around the car. Those which sense lateral accelerations (as in cornering) and longitudinal accelerations (as in acceleration and braking) are also housed beneath the seat. Steering input is monitored by a transducer on the system."

I may need to take back my comment about what David said about active/reactive because this article says that at this stage it really was more a reactive system.

[mat1]

Well, it sounds pretty active to me....

i think the difference between active and reactive is somewhat vague.

If a system senses a motion of the wheel, and then reacts, like a damper, or a simple spring, it is clearly reactive. But if a system senses a motion, and then pushes out a hydraulic ram or something, it is active. Of course it reacts to the sensors, and it is reactive in a way, but if we call that reactive, then every system is reactive.

Unless, maybe, you put in the system a map of the track, and the system reads the map, and changes the suspension accordingly. But this seems rather farfetched, doesn't it?

mat

[Darren Galpin]

Not so far fetched - they could do this for the automated gear changing in the early 1990s. Program in a map of the circuit, and the car would automatically change say from fifth to second as it knew what corner was coming up. If you programmed in a topological map, no reason why you couldn't get you suspension system to do the same.

[Marco94]

In the academic world, the term used is almost exclusivelly "active." A fully active system is used to refer to a system containing an actuator that can add power to a system, combined with a control system. When a system uses a damper, controlled by some control system, they speak of semi-active. In this case no power can be added to the system, it can only be taken away from it. Systems which do not use control systems are called passive.

The term reactive in racecar applications was introduced by Williams GPE. When they first introduced their system, they called it Active Ride. Lotus made objections, because they had some trademark on the term Active Suspension™ and thought the Williams *name* was to much like Active Suspension™. So from then on Williams refered to it as Reactive Ride.

[dolomite]

Originally posted by Darren Galpin
Not so far fetched - they could do this for the automated gear changing in the early 1990s. Program in a map of the circuit, and the car would automatically change say from fifth to second as it knew what corner was coming up. If you programmed in a topological map, no reason why you couldn't get you suspension system to do the same.

ISTR in the 1993 TV documentary 'a season with Mclaren' there is a long conversation between Senna and his race engineer at Monza over how to programme the active suspension to anticipate a particular sudden surface height change on the circuit.

[mat1]

Originally posted by Marco94
In the academic world, the term used is almost exclusivelly "active." A fully active system is used to refer to a system containing an actuator that can add power to a system, combined with a control system. When a system uses a damper, controlled by some control system, they speak of semi-active. In this case no power can be added to the system, it can only be taken away from it. Systems which do not use control systems are called passive.

So when a car has rams which don't just act as springs, but which are pushed out as well, the system is "active", and therefore the systems of Williams etc can e called active. Is that right?

mat

[Marco94]

Yep, well at least in the definition that I use. The Active/Reactive confussion is a direct result of OverActive™ lawyers. Silly really, but there you are.

[LeroyBoyce]

The Williams and McLaren WERE entirely active. They were capable of lowering the car to the ground for extra downforce in the corners, and then could raise the car by several centimetres on the straights, to minimise drag, and increase top speed. This was how Nigel Mansell managed 235mph in Hockenheim (in 1992).

I have, on old VHS, of the series mentioned earlier, broadcast by the BBC called "The Team - A season with McLaren". It was a fantastic series, and I've regularly written to the BBC to see if they could produce it on DVD.

In one episode, Senna is asking for the car to be 1mm lower through a particular corner, such was the sensitivity of the equipment.

There was no mechanical link between the driver and the car in that McLaren. The steering, throttle and brakes were all "fly-by-wire". There was a very strong rumour of Senna doing a "90%" lap at Silverstone, then getting out, and the car repeating the same lap with no driver!

For these reasons, 1993 will always be my favourite season! Fantastic!

Edited by LeroyBoyce, 24 December 2009 - 12:02.

[D-Type]

On the semantics question: the term "active" was coined as an opposite to "passive" and later the term "reactive" was introduced to help differentiate between different types of non-passive suspension. An analogue is the De Dion type rear suspension which was sometimes described as "independent" which it is relative to a "live" axle but should more correctly be described as "semi-independent" as the wheels do not move completely independently of one another.

[rallen]

I have, on old VHS, of the series mentioned earlier, broadcast by the BBC called "The Team - A season with McLaren". It was a fantastic series, and I've regularly written to the BBC to see if they could produce it on DVD.
......

For these reasons, 1993 will always be my favourite season! Fantastic!

I would love to get hold of that series on DVD too! yep, 1993 was in my opinion the last great season!

[dancin stu]

(remember the Gerhard Berger pit-exit)

I have heard about this, but as I was young at the time, any recollection of it has been lost. Could anyone elaborate more?

Thanks

SMC

[dancin stu]

Not so far fetched - they could do this for the automated gear changing in the early 1990s. Program in a map of the circuit, and the car would automatically change say from fifth to second as it knew what corner was coming up. If you programmed in a topological map, no reason why you couldn't get you suspension system to do the same.

This was used up until the introduction of the SECU in 2008, it may still be used for setting the differential now, but without having access to the strategies I couldnt be sure.... Certainly the In, Mid and Out are consistent with what was seen on the steering wheels before

To elaborate some more, having a "track map" stored in memory is not strictly correct, instead given that F1 drivers are all professionals, they should be able to achieve a lap distance which is within a few metres lap on lap (of course that depends what strategy is being used to calculate distance... ), so as long as you have a fixed point of reference every lap - which you do with a trackside beacon (either microwave or IR) - lap distance resets to zero at the same point every lap and so you can be fairly accurate with knowing where you are

Edited by dancin stu, 27 December 2009 - 09:27.

[schtix]

I've just found the Mclaren documentry here! It's great!

http://www.veoh.com/...v4253575CwXE8sa