US 4,358,164 A · Method and circuit for the generation of a speed reference signal for an antiskid system

Abstract

It is known that a vehicle speed reference signal suitable for slip control can be obtained by fully releasing the braking force at one or more vehicle wheels intermittently and to obtain the true vehicle speed from the signal provided by the free-rotating wheels. However, this technique results in the stopping distance of the vehicle being longer than desired since the braking effectiveness is considerably reduced. To avoid this disadvantage, the present invention compares a speed reference signal cyclically with the instantaneous velocity signals of the wheels and to weight the comparison result dependent on whether the instantaneous velocity signal comes from a driven wheel or a non-driven wheel. The weighted comparison result provides a correcting factor for the speed reference signal.

Claims54

Dependent claims

A method for generation of a speed reference signal adjustable to variations in the speed of a vehicle for use in a antiskid system for fluid-operated vehicular brakes comprising the steps of

comparing an existing speed reference signal cyclically and separately with an instantaneous velocity signal derived for each individual wheel of a vehicle to determine whether said reference signal is greater than, less than or equal to each of said instantaneous velocity signal;
weighting each result of said comparing step dependent on whether said instantaneous velocity signal producing said result comes from a driven wheel or a non-driven wheel;
producing a correcting signal from said weighted comparison results;
and
adjusting said reference signal in accordance
with said correcting signal.

3 more elements

A circuit for generation of a speed reference signal adjustable to variation in the speed of a vehicle for use in an antiskid system for fluid-operated vehicular brakes comprising:

a storage circuit storing therein a speed reference signal;
a comparator coupled to said storage circuit to compare said reference signal with n instantaneous velocity signals each obtained from a different one of n vehicle wheels;
a weighting circuit coupled to said comparator to weight each output signal of said comparator dependent upon whether said output signal of said comparator is derived from an instantaneous velocity signal generated by a driven wheel or a non-driven wheel;
and
a correcting circuit coupled to said weighting circuit and said storage circuit to form a correcting signal in response to said weighted output signals of said weighting circuit, said correcting signal being coupled to said storage circuit to adjust said reference signal stored therein.

2 more elements

Dependencies are inferred from the claim text.

Method and circuit for the generation of a speed reference signal for an antiskid system

Life of this patent

Method and circuit for the generation of a speed reference signal for an antiskid system

Life of this patent

Abstract

Claims54