The T-Word
The T-Word
The Year of Traction Control?
KEVIN CAMERON
When is traction control not traction control? The answer is, when the legal climate makes it too dangerous to call it by its proper name.
Just as anti-lock brakes contribute to the safety of their many users, so the new technology of traction control has a real safety contribution to make in motorcycling. Just as ABS is not a substitute for good operator judgment, so traction control requires experience and judgment in its use. Motorcycle ABS does not and cannot guarantee that when you grab the lever with panic force, the system will handle it in all cases. ABS works best when the machine is going straight, and it cannot create tire grip where there is none-as on gravel or snow. ABS can help, but it cannot replace the rider’s good judgment. Think of traction-control systems in the same way.
The basic contribution of both systems is to modify extreme situations that threaten steering control. Brake locking and rear tire spinning are those extremes.
Traction control is currently a routine option in automobiles, as is ABS. The motorcycle case is complicated by the fact that motorcycles lean over-or camber-to go around corners. An ideal ABS would measure lean angle, adjusting its sensitivity accordingly. We all know that when a motorcycle is at its traction limit at full lean, the tires have nothing further to give, so braking would simply make the machine fall down. The same is true of throttle application. If you apply power before lifting the machine from full lean, you may likewise fall down. That is physics that no technology can overcome.
In MotoGP the clear trend of development has been toward making machines easier to ride. The first level was to smooth the torque output of engines, eliminating regions of sudden spikes that could break rear tire traction. The second level was to measure the rate of engine rpm acceleration. If the “delta,” or rate of change, exceeded a certain level, the tire was breaking traction and the engine-control computer would retard the ignition to instantly reduce torque, thereby restoring traction-and directional control.
I talked with Stefano Perotta, an engineer with Marelli, a company that develops electronic systems for Formula One and MotoGP He said that the next level of sophistication is comparison of front and rear wheel speeds. Beyond that, current problems center on accurate vehicle speed measurement (GPS can do this provided there is adequate satellite signal) and on modulating traction control with lean-angle data. None of this is easy!
“You may have a very smart algorithm but you have all these special cases,” he noted.
What if the bike’s front wheel is in the air? What if the bike is leaned over, making the rolling radii of front and rear tires smaller than normal? What if the rider is cresting a hill, unloading the suspension?
“That’s a big challenge, and we are learning the hard way,” he said.
In a presentation made by Yamaha engineers at the Valencia GP this past racing season, Yamaha confirmed that its racing electronic systems are now using GPS data. When I talked with MotoGP riders at Laguna Seca, it was clear from their remarks that traction-control and anti-wheelie settings are now routinely adjusted on a separate, corner-by-corner basis. Lean-angle data has been available for years-l was shown an “inertial reference
unit” for gathering this data back in the 1990s. It was being used on a tire-test bike and its use was clearly regarded as routine at that time.
Manufacturers of production motorcycles know that traction control is the mirror image of ABS, with a similar potential to make motorcycles more safely rideable. What they fear is the customer who behaves like the brainless motorhomer in the movie The Darwin Awards. Informed that the vehicle has cruise control, she assumes it is an autopilot that controls everything—not just speed. And so, reaching highway speed, she engages the system and goes to the kitchen to make lunch.
As we know, the outcome of such things is that hot coffee must now carry a warning that hot coffee is hot and may cause burns or discomfort.
Having decided that it is too risky to call their traction control systems traction control, manufacturers are now furiously trying to put this genie back into the bottle. That is done by the time-honored technique of calling it something else. But what can they call it? Their representatives, who are not themselves engineers, are understandably unable to give a coherent alternative explanation of what it is that the systems do. It is embarrassing for these people to have to recite or make up nonsensical tales about systems that sense clearance or chatter between transmission dogs, and then act to “smooth operation.”
Just as we did with early ABS, we will all get through this affair, and the new technology will take its rightful, useful place in massproduced sporting motorcycles. We are now experiencing some of the hiccups that always accompany such changes. BMW has already announced its traction-control system and Ducati says it will introduce one soon-with eight settings!—on the 1098R homolgation special. When a technology exists, it seems artificial to withhold it from those for whom it could be a benefit.
Despite this, other makers remain shy of calling a spade a shovel. For the moment, we have to live with whatever official line they decide will give them the formal protections they require. Be careful with that coffee!
