METHOD AND SYSTEM FOR DETECTING AND MEASURING A BRAKING FORCE OF A BRAKING SYSTEM FOR VEHICLE, BY MEANS OF PHOTONIC SENSORS INCORPORATED IN A BRAKE PAD

摘要

A method is described for detecting and measuring a clamping force CF and/or a braking torque BT deriving from the actuation of a friction braking system for vehicle by means of detection performed in a brake pad 10 of the braking system. The method firstly comprises the step of encapsulating at least one fiber-optic strain sensor 2 in a casing 9 and incorporating the aforesaid casing 9 in a respective portion of friction material M adhering to a base plate or platform 11 of the brake pad 10, and sensitive to friction so that the shearing strain St-eff to which the casing 9 is subject in a tangential reference direction x is representative of the tangential force Ft acting on the brake pad 10, and the normal force Fn-eff to which the casing 9 is subject in a normal reference direction y is representative of the normal force Fn acting on the brake pad 10. The method then provides detecting, by the aforesaid fiber-optic strain sensor 2, a first strain S1 (present in a first position of the casing along a predefined first spatial direction w1 ), depending both on the normal force Fn-eff and on the tangential strain St-eff acting on the casing 9 in the first position; and furthermore of detecting, by the fiber-optic strain sensor 2, a second strain S2 (present in a second position of the friction material along a predefined second direction w2) depending both on the normal force Fn-eff and on the tangential strain St-eff acting on the casing 9 in the second position. The method then comprises the steps of generating, by the fiber-optic strain sensor 2, a first photonic signal L1, representative of the first detected strain S1, and a second photonic signal L2, representative of the second detected strain S2; and of receiving the aforesaid first photonic signal L1 and second photonic signal L2, by an optical reading/ interrogation unit 4, optically connected to the aforesaid fiber-optic strain sensor 2. The method finally provides determining, by the optical reading/ interrogation unit 4, the value of the first strain S1 and the value of the second strain S2, on the basis of the aforesaid first received photonic signal L1 and second received photonic signal L2, respectively; and determining a measurement of the clamping force CF and/or of the braking torque BT based on the determined values of the first strain S1 and the second strain S2.