US 4,819,994 A · Anti lock braking system for vehicle

Abstract

An anti lock braking system for a vehicle includes transducers acoustically coupled to a non-rotating member of the wheel assembly and adapted to provide an electrical output signal dependent upon the degree of acoustic emission activity in the non-rotating member. A detector is adpated to analyze when the electrical output signal which corresponds to the= acoustic emission activity in the non-rotating member falls to zero when brake pads are in frictional contact with the confronting surface of the wheel. The detector is adpted to send a feedback signal to a control device which controls the pressure applied to the wheel by the brake pads. Preferably the detector measures the instantaneous change of electrical output signal as a funtcion of the pressure applied by the brake pad. If the slope of the function is positive, the brake pressure is allowed to increase, if the slope is negative, the brake pressure is reduced and if the slope is zero the brake pressure is maintained so that maximum braking efficiency is obtained.

Claims12

Dependent claims

An antilock braking system for a vehicle comprising

a wheel having a confronting surface, at least one brake pad arranged to move into frictional contact with the confronting surface of the wheel,
a transducer acoustically coupled to the at least one brake pad, the transducer providing an electrical output signal dependent upon the degree of acoustic emission activity produced by frictional contact between the brake pad and the confronting surface of the wheel during a braking operation,
detector means for analyzing the electrical output signal of said transducer which corresponds to the level of acoustic emission activity,
control means which controls the pressure applied to wheel by the at least one brake pad,
wherein the detector means analyzes the electrical output signal to determine if there is locking of the wheel, the detector means sending a feedback signal to the control means when locking of the wheel is detected so as to at least reduce the pressure applied to the wheel in one mode of operation to prevent locking of the wheel.

2 more elements

An anti-skid braking system for a vehicle comprising

a wheel having a confronting surface, at least one brake pad arranged to move into frictional contact with the confronting surface of the wheel,
a transducer acoustically coupled to the at least one brake pad, the transducer providing an electrical output signal dependent upon the degree of acoustic emission activity produced by frictional contact between the brake pad and the confronting surface of the wheel during a braking operation,
detector means for analyzing the electrical output signal of said transducer which corresponds to the level of acoustic emission activity,
control means which controls the pressure applied to the wheel by the at least one brake pad,
wherein the detector means analyzes the electrical output signal to determine if there is skidding of the wheel, the detector means sending a feedbacks signal to the control means when skidding of the wheel is detected so as to at least reduce the pressure applied to the wheel in one mode of operation to prevent skidding of the wheel.

2 more elements

Dependencies are inferred from the claim text.

Anti lock braking system for vehicle

Life of this patent

Anti lock braking system for vehicle

Life of this patent

Abstract

Claims12