Anybody know what cruise control uses to tell whether to apply more or less power?
I'm thinking about long drives on straight, snow-covered roads.
In the past, I've gotten into minor trouble a couple hours into a drive doing, say, 35 mph over snow on a straight flat road that very gradually starts to incline.
What seems to happen is that as the incline increases, the driver applies a little more power to maintain speed - and the tires come a little closer to the limits of their adhesion. Then, at some point, right at the limit of adhesion, the incline increases a little more. The driver applies a little more gas and suddenly the wheels are spinning like crazy and the car fishtails until the driver catches on to what's happened.
I'm thinking that if cruise control works by measuring wheel rotations, if might assist in preventing that scenario. When the wheels brake loose, cruise control thinks the vehicle is going too fast, and does what the driver would do: backs off on the power - but in a hundredth of a second instead of a half second or even a second or so if the driver is sufficiently zoned-out...
Anybody tried cruise on snow?