摘要:
An anti-lock hydraulic brake system which includes a brake pressure generator composed of a master cylinder, a brake power booster inserted upstream thereof and a pressure modulator interposed between the master cylinder and the brake power booster. A resetting unit is formed by supplementing the pressure modulator with a valve assembly which connects a resetting chamber of the pressure modulator to either a pressure-compensating reservoir or an auxiliary-pressure source. The braking pressure in the wheel brakes is controlled, according to a time-multiplex method, by wheel valves inserted into the pressure-fluid conduits and by the pressure modulator. In order to check the operability of the brake and of the anti-lock control system, a pressure switch is connected to the pressure modulator and a test circuit is provided which, at predetermined points of time, initiates a test cycle, actuates the valves and compares the valves' operation with the reaction of the pressure switch.
摘要:
A control system and method for a brake system with anti-locking and/or traction slip control and sequential brake pressure modulation. A modulator pressure pattern is formed in a circuit (33) by measuring and evaluating variables determining the pressure in the control chamber of chambers (21) of a brake pressure modulator (4). The modulator pressure pattern represents, by approximation, the course of pressure in the modulator (4). This modulator pressure pattern is considered in the brake pressure control, that is in determining the excitation periods of the multi-way valves (13-16, 22, 23, 25) determining the pressure in a modulator chamber (21) of the brake pressure modulator (4) and in the wheel brakes (9-12). The pressure pattern is formed by integration of the valve excitation periods of the pressure increase and pressure decrease characteristics of the modulator (4) under consideration or of the entire system.
摘要:
A slip-controlled brake system comprises two hydraulically separated pressure medium circuits, to which the wheel brakes (14, 15 and 16, 17, respectively) of the wheels arranged diagonally at the vehicle are connected. In one diagonal (brake circuit 9) the braking pressure during slip control is controlled in phase, whereas in the second diagonal (brake circuit 10) individual brake slip control is possible by way of two individual inlet and outlet valve pairs (11, 18; 12, 19).
摘要:
The circuit configuration for a brake system having an anti-locking control generates pulse-type brake pressure control signals. For pressure rebuild-up after a pressure decrease, brake pressure is applied first at a steep and subsequently at a flatter gradient, this being achieved by a variable pulse (P1) and by short fixed pulses (P2) succeeding one another at a large interval. Circuits are provided rendering dependent the pulse and pulse break times (T.sub.1, T.sub.2, T.sub.k) determining the pressure build-upon the duration of the pressure build-up (T.sub.1) during the steep-rise build-up in the preceding cycle,on the duration (T.sub.1 +nT.sub.2) of the entire pressure build-up in the preceding cycle, andon the duration (T.sub.o) of the preceding pressure decrease, with the pulse times being so dimensionedthat, at a constant coefficient of friction and at a constant static pressure, the locking limit of the wheel is rereached after a predetermined period of time or after a predetermined pulse number. The duration of the variable and of the fixed pressure build-up pulses is computed from the pressure build-up of the preceding pressure or determined from a stored Table.
摘要:
A method is proposed for stabilizing a vehicle including a braking system that can be actuated by a driver of the vehicle for applying a braking force to at least two vehicle wheels. A braking force corresponding to driver specifications is applied at a first vehicle wheel of an axle, and a braking force that is smaller than the driver specifications is applied to a second vehicle wheel of the axle during a braking actuation by the driver when it is determined that an activation criterion is met. This provides a comfortable stabilization of the vehicle without an active buildup of braking force.
摘要:
Methods and devices for detecting cornering and in particular over-steered cornering, as well as a method and a device for stabilizing a vehicle in case of an over-steered cornering maneuver are described. The detection can be carried out with reference to wheel slip values and/or transverse acceleration values. The stabilization is carried out upon detection of the over-steered cornering maneuver by means of suitable interventions in the brake system.
摘要:
Methods and devices for detecting cornering and in particular over-steered cornering, as well as a method and a device for stabilizing a vehicle in case of an over-steered cornering maneuver are described. The detection can be carried out with reference to wheel slip values and/or transverse acceleration values. The stabilization is carried out upon detection of the over-steered cornering maneuver by means of suitable interventions in the brake system.
摘要:
In a method of improving the control behavior of an anti-lock control system, in particular, of the steerability and driving stability during deceleration in a curve, the slip condition of the individual wheels, by determining a slip differential value (SDI) , namely the difference between the momentary wheel slip (&Dgr;v) and the filtered wheel slip (fwsi) and a slip integral or slip summation value (SIi) are detected. The said slip summation value (SIi) is formed by integration of the difference between the momentary wheel slip (&Dgr;vi) and a predetermined permissive slip value (Serl.). Based on these quantities, a wheel condition value is determined which represents the angular slip of the wheel or the transverse dynamics of the wheel. By comparing the values of angular slip of the individual vehicle wheels it is possible to determine the vehicle condition, in particular, an “understeering” or “oversteering” situation.
摘要:
To improve the control behavior of an ABS system, more particularly, to suppress the unwanted effects of individual disturbances in the road surface, when subsequent to a partial braking operation an anti-lock control operation commences on a front wheel and the acceleration of the controlled wheel detected is in excess of a predetermined limit value, a quotient (Q.sub.1,2) is calculated from the maximum brake slip and the duration of pressure reduction until the reacceleration of the front wheel concerned. As soon as this quotient (Q.sub.1,2) exceeds a predetermined limit value (Q.sub.grenz), this is taken as the indicator of a disturbance. Therefore, the braking pressure on the wheel where the single disturbance occurs is increased in the subsequent stable phase until the acceleration falls below a predetermined limit value.
摘要:
A brake system with slip control for vehicles with front-wheel drive or all-wheel drive comprises two hydraulically isolated pressure-medium circuits (2, 3), to which one front wheel and one rear wheel each (VL, HR; VR, HL) are connected. Through a pair of valves (17, 19; 18, 20) consisting of inlet valve and outlet valve, the braking pressure in the two hydraulic pressure-medium circuits is varied upon recognition of an imminent locked condition. The braking pressure in the front-wheel brake is maintained constant by one additional valve (21, 22) connected upstream of the front-wheel brakes (4, 6) in the event of decrease or in the event of further increase of the pressure in the rear-wheel brake (5, 7) that is connected to the same hydraulic pressure-medium circuit (2 or 3, respectively).