General

General

Power steering long ago ceased to be merely a unit for improving comfort. Today it is more an indispensable aid for increasing safety while driving, improving handling and reducing the manual work required to operate the vehicle. Power steering is both a link in the driver vehicle road control loop and a sensor for determining the instantaneous dynamic state of the road and the vehicle. Its integration in the total vehicle concept is therefore of increased significance.

The amount of steering effort required is not only determined by the load on the front axle; a contributory factor is also increasingly dense traffic in towns which forces drivers to maneuver in the tightest spaces and when parking also requires the steering wheel to be turned while the vehicle is at a standstill. Due to power steering, the steering moment to be applied can be reduced and at the same time the ratio between the steering wheel and the wheels can be made more direct than in the case of a manual steering system.

The way in which a power steering system makes the work easier is most impressive when parking, but it is also the easiest of all problems to be solved. Much more difficult and also much more important for handling and safety is the problem of retaining the "feel" for the road. On the one hand this is a question of fully maintaining the sensory connection between the driver and the road by means of the steering wheel, steering gear and wheels, while on the other hand reducing the demands on the driver's muscle power, so that steering can be quicker and more precise