Method and system of controlling braking pressure in a vehicle brake
First Claim
1. In a vehicle braking system, in which the vehicle hasmeans (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 ofapplying 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).
1 Assignment
0 Petitions
Accused Products
Abstract
To prevent oscillation of a wheel being intermittently braked in an anti-slip or anti wheel block system, an increase of braking pressure, after a prior decrease, is controlled to occur during a first time interval which is short with respect to an oscillation period of the wheel if subjected to brake pressure pulses, so that the braking pressure increase will be small or short, e.g. about 3 milliseconds, comparable to stepped pressure increases after an initial wheel deceleration and permitted re-acceleration, the pressure then being maintained at an even level for an interval (T3) which, likewise, is short with respect to the intervals (T0, T4) between stepped increases. The respective time intervals can be controlled by individual, special pulse generators, or by suitable programming of microprocessor elements.
40 Citations
20 Claims
-
1. 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). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A 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, comprising means for controlling, selectively, application of braking pressure, maintenance of braking pressure, and reduction of braking pressure to the wheel of the vehicle, said control means controlling the selective braking pressure application means for (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, is 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 controlling, alternately, pressure increases as set forth in (a) and (d) above. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification