What we can (not) learn from F1: Driver-Car-Interfacing - Part2: Changing Mechatronic Parameters

This is the second part of the Driver-Car-Interfacing post, this time about changing mechatronic parameters. Part 1 about visualisation can be found here.

PLEASE NOTE: These are my personal findings. Acting according to these posts does not gain you any points in the design event or guarantee a trouble free season/event etc. It is just built on my experience as former participant and current official.

The posts subject line says "mechatronic parameters", so we should start with thinking about possible mechatronic parameters that have be changed on an FS car. There are none...that might sound a bit pragmatic, but technically (and assuming a perfect world) there is no need to change any mechatronic parameter during a dynamic event. However, in order to optimise the total points gained or just to survive Endurance there are many arguments to change mechatronic parameters while driving.




Let's start with the obvious: shifting. I think we all agree that changing gears (at least in combustion cars) maximizes on-track performance. This does not necessarily have to be done in a mechatronic way, but it has its advantages, which I will cover in another post. However, if shifting is somehow done with electronics involved, it can be considered to be a mechatronic parameter. In F1 shifting via paddles on the steering wheel was pioneered by Ferrari in 1989 in the Ferrari 640. This on board video shows the early days of paddle shifting. Note how the driver uses his right index finger to shift up. F1 uses paddles on the back of the steering wheel, which can be seen here, because it is probably the most ergonomic solution. The driver's hands can remain on the wheel and he can also maintain his grip while shifting. Another solution is to mount buttons on the front of the steering wheel. We tried that in 2006 and 2007, but it was a great relief for the drivers when we changed to paddles in 2008. So there is a good reason why most of the teams in F1 and FS chose paddles. Therefore, if you do mechatronic shifting, using paddles on the back of the steering wheel seems to be the best solution.

Nowadays teams also start to control the clutch mechatronically. F1 has been doing this for quite some time and uses another set of paddles to do that. They have two paddles which are used for the same function under normal conditions which is just disengaging/engaging the clutch. During the start of a race, one of the paddles is used to move the clutch to its bite point and the second paddle is used to completely engage the clutch. Thus the resolution is effectively doubled, which probably helps to control wheel slip. It was also always done with paddles in F1, since the mechatronic clutch has been introduced, and seems to be the best solution for the same reasons already stated above about gear shifting paddles.

Drag reduction systems have also gained visibility recently in FS, for example on the car of KIT, which can be seen here. F1 has the same mechanism called DRS. Frankly I do not remember exactly how KIT control their DRS, but I assume that it is just a push button on the steering wheel. It could of course also be done automatically by making it dependant on lateral acceleration, throttle position and ground speed for example. F1 uses either a push button on the steering wheel or an extra (very small) pedal left of the brake pedal, which can be seen in the following picture (source: auto, motor und sport).

Using a small extra pedal seems to be more ergonomic and according to the F1 teams using it, the advantage is that lifting the foot of the pedal closes the wing a short time before the driver starts to brake, which gives the air stream more time to attach to the wing again, before the downforce is needed for braking. If that was really needed, all teams would probably be using it...so nothing is for sure.
I wonder, if we will see this solution also in FS, provided that it is not already used and I did just miss it.

The next parameter to cover is the brake balance. I keep seeing electronically controlled brake balance bars appear and disappear in FS. From time to time some teams do it and then skip doing it the next year. It might be beneficial to do it electronically since F1 teams did it also, while it was allowed. The current F1 rules do not allow that which is why we see drivers regularly reaching in the left side of the cockpit to change the brake bias. The FS track characteristics and also training levels of FS drivers are different to F1, therefore I doubt whether it would really be necessary to have electronic means of changing the brake bias while driving just to adjust it from corner to corner. Therefore it might be totally ok for combustion cars to also do it through a mechanic connection.
For electric cars things are a bit different. Most teams have rear-wheel drive and also use their motors to regenerate energy. If they have to restrict/change the braking torque being generated by regeneration due to thermal management for example, it might be very handy to automatically shift some braking force rearwards to keep the car in balance while braking. Please note that this is just an idea and I am not totally sure how a Scrutineer would think about that. You would at least want to make sure that only a certain amount of brake capacity can be shifted between front and rear by using mechanical stops on the balance bar for example. This avoids that an erratic algorithm could transfer all the braking capacity to the rear wheels, which would result in a massive spin in the best case.

I have now been talking about the obvious mechatronic parameters, but if you look at an F1 steering wheel, there are many more buttons and switches. The following picture (source: Sauber F1 Team) shows the front of the Steering Wheel of the Sauber C32 including descriptions for each and every button and switch.

The full size picture can be found here.
You might have noticed that they have lots of buttons and switches. Most of them affect systems which are either not allowed in FS or which are not really used yet. However, even if we take these systems away, enough switches would remain to change:

• Engine maps (IC) / Torque Characteristics (EV)
• Traction / Launch Control Settings
• Shift Maps (if done automatically for example or to change the RPM Indicator lights)
• Clutch Characteristics
• Pit Radio
• Accessing information on the display
• Anti-Roll-Bar adjustments (rare, but I have seen it)
• Data Logging and Telemetry Options
• etc...

As you can see on the picture above, F1 uses rather big push buttons and rotary switches. Some of them do even look bulky, which is rather uncommon for F1. A requirement, which is forgotten by steering wheel designers from time to time is that all these buttons and switches must be operated by the driver while wearing gloves and also usually while driving. Therefore these elements need to have a certain size such that the driver can operate them while not looking at the steering wheel.

For parameters, which are only changed when standing still, you could get away with having some push buttons and by showing a navigation menu on the display. But most of these parameters are used while driving on the track and if your driver has to pay significant attention to the steering wheel to change something, he will certainly lose time.

F1 does a good job in my opinion by providing buttons and switches which provide a good feel to the driver and do not consume much brain/attention capacity to change settings. Most teams have already adapted this and use similar buttons and switches.

A rather obvious requirement is for the buttons and switches to be water-proof.

There is one big difference between F1 and FS, which should theoretically lead to less buttons and switches on FS steering wheels: It is not prohibited to change parameters via a remote connection in FS. Thus changing engine or shift maps etc. could all be done remotely by the data or performance engineer without bothering the driver. Some of those changes could even be done automatically by algorithms running on ECUs on the car. There is of course always the chance that the telemetry connection fails or that the algorithms are erratic...in that case the driver and the team will probably be thankful for a little switch...

Please note:

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