Wednesday, November 11, 2009

The Steering Wheel



Nothing is simple in F1, at least not these days. And the steering wheel is of course no exception. Just 15 years ago, the steering wheels were still relatively simple, usually featuring a push-to-talk button for the radio and maybe 1 or 2 other buttons. However the modern F1 car has made dramatic leaps in terms of driver controls. We'll explore the evolution of the steering wheel in this installment.

First off, the steering wheel today is one solid unit that is removed from the car to allow the driver to get in and out of the cockpit. The first thing you'll notice when a driver crashes or gets out is the removal of the wheel, sometimes in anger, as Vettel did following a rain-soaked qualifying effort. This should give you an idea of how cramped the modern F1 cockpit is.



Classic F1 even in the late 80's featured most of the controls and instrumentation on a 'dash' inside the cockpit with relatively few controls on the wheel. Here you can see Michael Schumacher's '89 Benneton with only two buttons on the front of the wheel. The 'N' button is the neutral button; the driver will hit this to put the car into neutral. I believe the green button is the radio.

The back of the wheel has four (or now sometimes six) 'paddles' or levers. The two levers near the top of the wheel are used for upshifts (right-side) and down-shifts (left-side). The driver needn't use the clutch for upshifts or downshifts while on the track. The bottom two levers are both for the clutch of the car and have identical function. The clutch lever in an F1 car is only used a few times during the race; for the start, for leaving the pits, and to prevent the engine from stalling if the driver spins.



More recently, teams have adopted a third set of paddles located below the shifters but above the clutch. These two paddles can be used to toggle various settings, most often of which is the ECU map. The ECU is the computer that controls the engine. Its responsible for running all of the engine parameters, and a 'map' is a particular set of parameters for the engine. Different maps can make the engine behave in different ways. For example, you can have a map that is optimized for torque, another optimized for top speed, and a third optimized for traction.

The idea here is that normally the driver will use two fingers, one on the shifter and one on the ECU map selector paddle, and pull them at the same time. This allows for an engine map optimized per gear. Without the ECU map sector paddles, the driver would have to shift, and then turn a rotary switch on the front of the wheel to change maps. There is a second advantage here, which is that a good driver can actually delay or advance switching maps independent of the gear change. An example might be using a traction-optimized map accelerating out of a slow corner in second gear, and then switching just the map for more power as the car gains speed and rear traction becomes less of a concern. We have seen this especially in the wet from drivers like Hamilton and Kubica. Some have even equated their 'dance of paddles' to a trumpet player.

Maps can also be used to save fuel. Often you'll hear a radio call instructing the driver to use a certain 'mix' which is really changing engine maps to preserve fuel (or optimize power). Typically the drivers will go to a fuel-saving map if a safety car is deployed. The engineers may also request a more conservative map if they suspect issues with the engine.



To simply the electronics and make the car more modular, the instrumentation and most of the controls for the car were moved onto the wheel itself. One of the most important instruments is the tachometer, or rather the 'shift lights'. An F1 car will typically have a series of green, yellow, and red lights that sequentially illuminate as the car approaches redline, indicating to the driver that its time to shift up. Some teams also feature a small informational screen on the wheel for warnings or messages, but generally this is too much for the driver to monitor, and since all the car's data is transmitted in real-time back to the pits, the health of the car's systems is usually monitored by dedicated engineers in the garage.

So now lets tackle the button's and knobs on the front. Here is a picture of Robert Kubica's 2009 wheel, and a list of the functions.



1. Info of FIA/Race Control - When a safety car is deployed, race control sends a signal that will illuminate this light on the driver's wheel.

2. Shift lights - a very simple tachometer

3. Multi purpose display (engine revs, lap times, speed, gear, etc)

4. Neutral (usually when at the pit stop)

5. W – activate front wing - In 2009, it was allowed for drivers to be able to adjust part of the front wing six degrees to increase/decrease front down-force

6. Multi purpose button

7. K – KERS boost button

8. – (presetting down)
9. + (presetting up)

10. Ack – Acknowledge - This button is used by the driver to acknoledge he has heard a radio transmission from the pits, and can also be used to acknowledge that the team is uploading parameter changes to the driver's car in real-time.

11. PL – Pit lane limiter - This button keeps the car from exceeding the pit lane speed limit.

12. spare - I'm guessing a just a spare button.

13. R – radio

14. Box – pit stop - Not exactly sure, as usually the call to 'box' or pit is made by the team to the driver via radio, so I assume this is used by the driver to immediately communicate he needs to pit, usually because of damage to the car.

15. BP – Clutch - Again, not exactly sure, but the 'BP' designation leads me to think this stands for 'bite point' for the clutch. In preperation for the start, the teams will perform a few practice starts, and during this time they try to find the ideal 'bite point' for the clutch, which is the point where the clutch is partially engaged during the start, yeilding the best acceleration. Teams tune this parameter per track.

16. SC – Safety Car - Once again, I'm not exactly sure, but my guess is that this button puts the car into 'safety car' configuration; mainly switching engine maps to preserve fuel.

17. Differential - This is the deceleration setting of the differential (corner entry). This allows the driver to vary how much slip the differential should allow between the rear wheels while the car is under braking. Increasing this will limit the slip, which will cause the car to be more stable under braking, but may make the car harder to turn.

18. Preload Differential Settings - the preload is a certain amount of torque added to the differential to control when it locks.

19. Differential - This is the acceleration setting of the differential (corner exit). This varies the slip between the rear wheels while the driver is accelerating out of corners.

20. Cruise Control - This one took me a while, but I understand that its basically a set km/h speed setting just like the cruise control in your road car. Its apparently used when following the safety car. The rationale here must be that the computer can do a better job of maintaining a set speed and using less fuel than the driver (which is true in road cars).

21. Selector (KERS, Front Wing, RPM)

22. Tire adaptation - This has the settings for the various tires, including intermediates and full-wets, so I imagine it controls some settings in the ECU and differential to optimize performance for the respective tire type.

23. Presetting front wing - default angle for the front wing

24. Pedal map - throttle pedal sensitivity (and/or a non-linear throttle map)

25. Fuel mix - ECU map

26. Upshift paddle
27. Downshift paddle
28. Clutch

A lapse in 08 and 09

Short post here; basically the 08 and 09 seasons found me wrapped up with many things and unable to write. However this off-season I plan to post about some of this season's great developments, including the double-decker diffuser which Brawn used to great effect to secure both the Driver's and Constructor's championships. KERS (kinetic energy recovery) also featured prominently in the season, and I'll also be posting on this one season of KERS (since it is now banned for 2010). Anyway, sorry for the lapse, and I hope you'll enjoy reading.