I was driving to NYC recently and considered the tire. I considered the loss of traction around a corner. Certainly due to more than one factor. You could address the problem in several ways, most of which are already being done. Moving air dams can adjust to push down on the outer edge of the car. Suspensions can also automatically adjust to keep pressure down on the tire surface. Tires can be made wider, and cars can be made with an ultra low center of gravity, both of these being obvious in a car like the Viper. That’s all great, but I think I came up with another method.

Imagine your tire is just a lot of rubber knobs. As they rotate, each row of knobs rotate down, contacts a point on the road and then rotates up. Parallels can be made to the surface of a runner’s shoe contacting the ground. Now consider your car as you go around the typical highway on-ramp or off-ramp. Your steering wheel is held in a particular direction and ( whether or not you aggressively test this out) you know that you have a limitation to how fast you can go without the car starting to slip and eventually spin out of control. This comes from the force of the turn on your vehicle. If you are turning around a right turn, the vehicle experiences G-forces to the left, and vice versa. This force could be likened to just driving straight down a section of road and having the road tilted to one side or the other. Pretty straight forward physics stuff.

Some times when I try to first get my mind around a concept I like to go the the extreme ends of the spectrum.   For instance the concept of a see saw – it’s easy to imagine the mechanical advantage of the thing if you simply imagine one that’s 50 feet long on one side and 5 feet on the other.  So in thinking of this loss of traction I went to the extreme, and considered driving as a tremendous wind storm was blowing across from one side of the road to the other, or perhaps driving on a road that was banked nearly 90 degrees to one side or the other. In either case, I imagined the car would start sliding off the road to the left or the right. What could be done? Well if you took all 4 tires and rotated them towards the wind, or to the high side of the bank you were on, and could power them all evenly, as with an all wheel drive car, you may not get our of your slide, but you would be maximizing what your tires could do about it. The downside to this of course, is that you would be going in a direction other than where you wanted to. Logically I conclude that ideally, you would just be able to drive straight in the direction you wanted, and in the worst case you would have to turn all 4 of your tires entirely 90 degrees to avoid sliding off the road, but in the process you lose all ability to go forward. Well we are never going to drive along the side of a building or through a 200 mile per hour windstorm, but logically I believe we can draw some conclusions.

My idea is simple, and I have not found any mention of the concept in even some of the advanced 4 wheel steering literature I found searching around. Simply, all 4 tires need to be turned slightly (I’m assuming around 1 to 2 degrees – probably 5 at the most) into the turn. This is not 4 wheel steering in the way it is used today, but rather just a small amount of turning.  Let’s call it “pivoting.” The rear wheels would be simply able to pivot left and right up to 5 degrees. The front wheels would be normally functioning, but have a similar pivot left and right up to 5 degrees.

My premise is that by turning all 4 tires slightly into the turn, you would be negating, to some degree, the force pushing your car off the road, while still keeping the bulk of your force going in the direction you desire to go. This pivoting / turning action would be computer controlled and could either be strictly math based or it could be accelerometer based. By that I mean that the computer could either just make the pivot adjustment by knowing that the car is traveling, let’s say, at 40 mph and the wheel is turned to X number of degrees to the left.  The computer could also just respond by pivoting the tires into the direction that an in-board accelerometer tells it to. The technology is already here to make this happen. For example, there is an accelerometer in your smartphone right now. In an iPhone 4 for instance, the accelerometer is so advanced that if you set your iPhone next to your keyboard on your desk, it can be used to accurately determine what you are typing.

I have no way to build an test this system out to prove that there are gains to be made with this method. This is, after all, some thoughts on the subject as I drive down the highway, concerning what is overall a trillion dollar industry. An industry that employs some of the most talented and well funded engineers in the world. Surely someone has thought of doing this? 🙂