Abstract: A method of controlling the brake pressure in an anti-lock brake system of a dual-track vehicle wherein pressure raising pulse trains are applied to the brakes of the rear wheels of the vehicle provides for modified "select-low" control of a kind with which the brake of the one wheel which first is instable on the rear axle is fed with a pressure raising pulse train having a smaller mark-to-space ratio or pulse duty factor than the pressure raising pulse train applied to the brake of the other, the stable wheel of the rear axle.

Abstract: A method of controlling the brake pressure in an anti-lock vehicle brake system provides for short distances to stop to be reached even with greatly differing mass moments of inertia by calculating the pressure reduction period of a control cycle currently under way as the product of a first factor and a second factor. The first factor depends on the pressure reduction period in the preceding control cycle, and the second factor depends on the maximum re-acceleration of the wheel in the preceding control cycle.

Abstract: An anti-skid brake control system for a motor vehicle includes wheel sensors for producing signals representative of the rotational speed of each road wheel; an evaluation circuit responsive to the wheel speed signals for determining a reference speed that approaches the speed of the vehicle and for producing brake pressure control signals, in dependence upon the reference speed and the road wheel speeds; and a brake pressure controller responsive to the brake pressure control signals for varying the brake pressure applied to the road wheels. The evaluation circuit includes means for determining the vehicle speed from the average increase of the reference speed and this vehicle speed, so determined, is used to determine an increase in the value of the reference speed during periods of braking instability.

Abstract: In a method of controlling the brake pressure in the rear wheel brakes of a double-track vehicle, wherein the rotational speeds at least of the rear wheels are measured and the brake pressure is lowered, kept constant, or raised, depending on the unstable or stable states arising at the individual rear wheels, the pressure in the brake of a stable rear wheel being approximated at least temporarily to the pressure in the brake of an unstable rear wheel, it is provided that, upon initiating a pressure decrease in the brake of an unstable rear wheel, the pressure in the brake of the stable rear wheel is kept constant for a predetermined period of time (.DELTA.t) and then decreased until the pressure in the brake of the unstable wheel is either kept constant or increased. This guarantees shorter stopping distances and at the same time provides a smaller difference in the braking torques at the rear axle, at good stability of the motor vehicle.

Abstract: For measuring the rotational speed of a wheel in an antilocking protected vehicle brake system a rotational speed sensor is provided in which in accordance with the rotational speed of the wheel signals are electromagnetically induced which have an amplitude and frequency which increase regularly with the rotational speed. When due to error sources the amplitude of the induced signal does not increase with the frequency of the signal a rotational speed measured value is determined by means of the measured amplitude, i.e. not on the basis of the measured frequency. To avoid erroneous measuring signals it may likewise be provided that when the amplitude of the signal does not increase with its frequency the last measured value of the frequency of the induced signal at which the amplitude still increased with the frequency is used to determine the speed of rotation.

Abstract: For measuring the rotational speed of a wheel is an antilocking protected vehicle brake system a rotational speed sensor is provided in which in accordance with the rotational speed of the wheel signals are electromagnetically induced which have an amplitude and frequency which increase regularly with the rotational speed. When due to error sources the amplitude of the induced signal does not increase with the frequency of the signal a rotational speed measured value is determined by means of the measured amplitude, i.e. not on the basis of the measured frequency. To avoid erroneous measuring signals it may likewise be provided that when the amplitude of the signal does not increase with its frequency the last measured value of the frequency of the induced signal at which the amplitude still increased with the frequency is used to determine the speed of rotation.

Abstract: An anti-locking brake system is described in which pressure drops produced in the event of rapidly succeeding wheel retardations and wheel accelerations are restrained. This is achieved by a summing circuit having a sum to which a numerical value is added; the sum is reduced according to a given function. The sum value present in each case is a measure of how the pressure reduction is to be restrained, for example, by raising thresholds.

Abstract: An anti-locking brake control system for a motor vehicle comprises wheel speed sensors for determining the speeds of the individual vehicle wheels, an evaluation circuit which receives the wheels speed signals and generates brake pressure control signals, and a brake pressure control device responsive to the brake pressure control signals for controlling the brake pressure applied to the wheels. The evaluation (processing) circuit includes a brake pressure control unit which operates in such a manner that, after brake pressure decays, the brake pressure is first increased in a timed build-up with reference to the brake pressure build-up in a preceding control cycle, and thereafter the brake pressure is further increased by a sequence of pulses until an instability is again detected.