Abstract
An automobile loses its running stability when it slips due to the rapid acceleration, deceleration or braking. The driving force of automobiles is transmitted by the frictional force between the tires and the road surface. The slip ratio determined by the car-body speed and the wheel speed. We have used a disturbance observer for estimating the car-body speed because it is difficult to measure. However, the method by the disturbance observer has a ploblem such as the speed includs a lot of errors. On the other hand, that using GPS has little of errors. So, we propose a new drive control system using GPS.
