Method and system of controlling braking pressure in a vehicle brake

In a vehicle braking system, in which the vehicle has

• means (1, 2) for providing a signal representative of speed, acceleration and deceleration of a wheel of the vehicle,
• means (5a, 5b, 6a, 6b) for applying, selectively, higher or lower braking pressure on the wheel,
• and control means (3, 4) responsive to said signals and controlling the braking pressure, in steps or pulses, such that, sequentially, braking pressure pulses of respectively controlled different pressure levels follow each other,
• a method of controlling the braking pressure including the steps of
• applying braking pressure;
• sensing wheel deceleration as the result of applied braking pressure;
• determining if said wheel deceleration exceeds a predetermined level, and, if so, inhibiting further increase of braking pressure;
• and, thereafter, increasing braking pressure in a further pressure increase phase, wherein, in accordance with the invention, the pressure increase phase comprises the steps of
• (a) increasing braking pressure during a first time interval which is short with respect to an oscillation period of the wheel if subjected to a brake pressure increase pulse, so that the braking pressure increase will be small and short;
• (b) then maintaining braking pressure for a second interval of time which, also, in short with respect to said oscillation period;
• (c) then increasing braking pressure during a third interval of time which is longer than said first time interval;
• (d) then maintaining braking pressure during a fourth interval of time which is longer than said third time interval;
• and then repeating, alternately, sequentially, the pressure increase step (a) and the pressure maintenance step (d).