Patent ID: 7040718

Claim:
A calibration process for a pneumatic-assistance servomotor for a braking circuit of a motor vehicle, said servomotor ( 14 ) comprising a negative-pressure chamber ( 24 ) that is connected to a negative-pressure source and a working chamber ( 26 ) that is selectively connected with the negative-pressure chamber or to atmospheric-pressure ambient air, wherein said chambers are separated by a moving partition wall bearing an axial piston for the actuation of a hydraulic master cylinder ( 16 ), characterised in that said process consists in measuring and recording, for a determined negative pressure inside the negative-pressure chamber ( 24 ), the coordinates of several points of an operating curve of the servomotor, using an orthonormal plot of axes, representing an input parameter of the servomotor and an output parameter of the servomotor or of the master cylinder associated with said servomotor, each of said several points being located beyond a jump phase and on either side of a saturation point on said operating curve and representing measured and recorded values of said input and output parameters as regards to two points (P 1 , P 2 ) of the operating curve situated between the jump phase and a saturation point and two other points (P 3 , P 4 ), located beyond the saturation point.