Abstract: The wheel speeds are measured by wheel speed sensors and are fed to an evaluation circuit. By way of the evaluation circuit, brake pressure control signals at least for increasing pressure and for decreasing pressure for a specific duration are then produced for the closed-loop/open-loop control of the wheel movement behavior. Moreover, brake pressure control signals are also usually output by the evaluation circuit in order to keep the brake pressure constant. These brake pressure control signals are fed to brake pressure control units for varying the brake pressure. The core of the invention consists in the fact that the duration at least of the first decrease in brake pressure at the front wheels is selected to be dependent on the speed of the vehicle at the start of braking.

Abstract: A wheel anti-blocking control system (ABS), in which, subsequent to a brake pressure drop, the first brake pressure rise pulse .DELTA.P.sub.2 is controlled, in dependence on the preceding brake pressure drop (.DELTA.P.sub.1) and on a quotient defined by the relationship: ##EQU1## in which +.omega..sub.m and -.omega..sub.m are representative of maximum angular acceleration/deceleration of the respective wheel being controlled and .alpha. is a factor somewhat less than unity, and which may vary in dependence on the direction of movement of the vehicle, for example whether the vehicle is moving in a straight path or is moving along a curve. If moving along a curve, so that angular acceleration is involved, the factor .alpha. is reduced.

Abstract: To control transmission ratio of a continuously variable transmission connected to a combustion engine (e.g., for optimal fuel efficiency of a powered vehicle), effective diameter of pulleys is controlled in response to an electrical signal. A control signal suitable for comparison with hydrostatic pressure values is produced by a computing device based on input signals representing load, speed, and other operating conditions and based further on stored data representing engine characteristics. A control signal is conveniently used to control hydrostatic pressure by means of electromagnetically operated valves. Especially when pulsed valves controlled by digital electric signals are used, a reservoir is used to establish a steady hydrostatic pressure. Such control device is readily adapted to different engines by replacement of stored characteristic data.