Process for the restoration of brake pressure in a motor vehicle with anti-lock brake system

A process for restoring brake pressure in a brake of a motor vehicle having an anti-lock brake system which subjects said brake to a brake regulating cycle when the brake pressure which is measured by means of a pressure sensor reaches a deregulating pressure P.sub.max, said brake regulating cycle comprising a pressure reduction phase wherein the brake pressure is reduced from said deregulating pressure P.sub.max to a holding pressure P.sub.min, a pressure maintenance phase wherein said holding pressure P.sub.min is maintained, and a pressure restoration phase wherein said brake pressure in said brake is increased, said process comprising,

• storing the deregulating pressure P.sub.max and the holding pressure P.sub.min applicable during each brake regulation cycle of said anti-lock brake system,
• followirg said pressure maintenance phase, increasing the brake pressure in said brake with a steep pressure gradient PG.sub.H in a first pressure increase stage until a pressure level P.sub.K is reached, and
• thereafter increasing the brake pressure in said brake with a low pressure gradient P.sub.N in a second pressure increase stage,
• wherein said steep pressure gradient PG.sub.H is calculated as a function of the average value of P.sub.max and P.sub.min for a number of previous brake regulating cycles,
• wherein said low pressure gradient PG.sub.N is calculated as a function of the average value of P.sub.max for a number of previous brake regulating cycles, and
• wherein said steep pressure gradient PG.sub.H is determined according to the formula
• PG.sub.H =K.sub.3 +K.sub.4 (P.sub.k -P.sub.desired)
• wherein K.sub.3 has a value between 5 bar/s and 50 bar/s, K.sub.4 has a value between 3/s and 20/s, and P.sub.desired brake pressure value prescribed by said anti-lock brake system.

A process for restoring brake pressure in a brake of a motor vehicle having an anti-lock brake system which subjects said brake to a brake regulating cycle when the brake pressure which is measured by means of a pressure sensor reaches a deregulating pressure P.sub.max, said brake regulating cycle comprising a pressure reduction phase wherein the brake pressure is reduced from said deregulating pressure P.sub.max to a holding pressure P.sub.min, a pressure maintenance phase wherein said holding pressure P.sub.min is maintained, and a pressure restoration phase wherein said brake pressure in said brake is increased, said process comprising,

• storing the deregulating pressure P.sub.max and the holding pressure P.sub.min applicable during each brake regulation cycle of said anti-lock brake system, and
• following said pressure maintenance phase, increasing the brake pressure in said brake with a steep pressure gradient PG.sub.H in a first pressure increase stage until a pressure level P.sub.K is reached, and
• thereafter increasing the brake pressure in said brake with a low pressure gradient PG.sub.N in a second pressure increase stage,
• wherein said steep pressure gradient PG.sub.H is calculated as a function of P.sub.max and P.sub.min for at least one previous brake regulating cycle,
• wherein said low pressure gradient PG.sub.N is calculated as a function of P.sub.max for said at least one previous brake regulating cycle, and
• wherein said steep pressure gradient PG.sub.H is determined according to the formula
• PG.sub.H =K.sub.3 +K.sub.4 (P.sub.K -P.sub.desired)
• wherein K.sub.3 has a value between 5 bar/s and 50 bar/s, K.sub.4 has a value between 3/s and 20/s, and P.sub.desired is a desired brake pressure value prescribed by said anti-lock brake system.

A process for restoring brake pressure in a brake of a motor vehicle having an anti-lock brake system which subjects said brake to a brake regulating cycle when the brake pressure which is measured by means of a pressure sensor reaches a deregulating pressure P.sub.max, said brake regulating cycle comprising a pressure reduction phase wherein the brake pressure is reduced from said deregulating pressure P.sub.max to a holding pressure P.sub.min, a pressure maintenance phase wherein said holding pressure P.sub.min is maintained, and a pressure restoration phase wherein said brake pressure in said brake is increased, said process comprising,

• storing the deregulating pressure P.sub.max and the holding pressure P.sub.min applicable during each brake regulation cycle of said anti-lock brake system,
• following said pressure maintenance phase, increasing the brake pressure in said brake with a steep pressure gradient PG.sub.H in a first pressure increase stage until a pressure level P.sub.K is reached, and
• thereafter increasing the brake pressure in said brake with a low pressure gradient PG.sub.N in a second pressure increase stage,
• wherein said steep pressure gradient PG.sub.H is calculated as a function of P.sub.max and P.sub.min of the last brake regulating cycle,
• wherein said low pressure gradient PG.sub.N is calculated as a function of P.sub.max of the last brake regulating cycle, and
• wherein the steep pressure gradient Pg.sub.H and the low pressure gradient PG.sub.N satisfy the equation ##EQU7## wherein P.sub.desired is a desired brake pressure value prescribed by said anti-lock brake system and K.sub.10 has a value between 25 bar/s and 100 bar/s, so that there is a smooth transition between said first and second pressure increase stages.

A process for restoring brake pressure in a brake of a motor vehicle having an anti-lock brake system which subjects said brake to a brake regulating cycle when the brake pressure which is measured by means of a pressure sensor reaches a deregulating pressure P.sub.max, said brake regulating cycle comprising a pressure reduction phase wherein the brake pressure is reduced from said deregulating pressure P.sub.max to a holding pressure P.sub.min, a pressure maintenance phase wherein said holding pressure P.sub.min is maintained, and a pressure restoration phase wherein said brake pressure in said brake is increased, said process comprising,

• storing the deregulating pressure P.sub.max and the holding pressure P.sub.min applicable during each brake regulation cycle of said anti-lock brake system,
• following said pressure maintenance phase, increasing the brake pressure in said brake with a steep pressure gradient PG.sub.H in a first pressure increase stage until a pressure level P.sub.K is reached, and
• thereafter increasing the brake pressure in said brake with a low pressure gradient PG.sub.N in a second pressure increase stage,
• wherein said steep pressure gradient PG.sub.H is calculated as a function of the average value of P.sub.max and P.sub.min for a number of previous brake regulating cycles,
• wherein said low pressure gradient PG.sub.N is calculated as a function of the average value of P.sub.max for a number of previous brake regulating cycles, and
• wherein the steep pressure gradient PG.sub.H and the low pressure gradient PG.sub.N satisfy the equation ##EQU8## wherein P.sub.desired is a desired brake pressure value prescribed by said anti-lock brake system and K.sub.10 has a value between 25 bar/s and 100 bar/s, so that there is a smooth transition between said first and second pressure increase stages.