Abstract: To improve the control behavior of an ABS, a driving situation on a low coefficient of friction is quickly and reliably identified. To this end, the reacceleration of the non-driven wheels following a control-induced braking pressure reduction is analyzed, and the existence of a low coefficient of friction is identified if simultaneously in the reacceleration phase the maximum reacceleration of the two non-driven wheels is below a predefined limit value and the maximum filtered acceleration is below a specific predefined limit value, and if the duration of the positive variation of the filtered acceleration in this phase exceeds a predetermined time limit value. When these conditions are satisfied, braking pressure reduction in the following instability phase of the wheels is increased, for example, by a permanent actuation of the pressure reducing valves.

Abstract: In a method of improving the control behavior of an anti-lock control system, criteria for identifying a cornering situation and the direction of curve are obtained from the rotating behavior of the vehicle wheels. For cornering identification, the wheel slip values (&lgr;i) are filtered by way of a first order, low pass and the filtered values are compared. The time constant (T) of the low pass filter is varied as a function of the acceleration (ai) of the respective wheel (i). The time constant (Ti) of the filter starting from a minimum value (Tmin), is increased according to the relation Ti=Tmin+(agrenz−ai)/k1 as soon as the acceleration (ai) of the respective wheel (i) drops below a predetermined limit value (agrenz).

Abstract: To improve the control behavior of an anti-lock control system, in a method wherein the rotational behavior of the wheels is measured and evaluated and a vehicle reference speed, wheel slip data and wheel acceleration data and other control parameters are determined, the lowest wheel speed (v.sub.min) is continuously compared with the highest wheel speed (v.sub.max) during a braking operation. In the event of an approximate correlation between the lowest (v.sub.min) and the highest (v.sub.max) wheel speed and if the correlation lasts longer than a predefined length of time (T1, T2), the pressure in the brakes of the front wheels is permitted to increase or caused to increase after this length of time. The duration of the predetermined length of time (T1, T2) can be varied as a function of the acceleration or deceleration (v.sub.3, v.sub.4) of the non-driven wheels.

Abstract: A method of improving the control behavior of a controlled brake system, wherein the rotational behavior of the individual vehicle wheels is measured and evaluated for determining control quantities, and wherein slip threshold values for the commencement of the control are predetermined, includes that the slip threshold of a wheel is increased for a predefined time interval as a function of the acceleration after preceding instability in order to suppress the effects of road surface irregularities. This increase may be carried out in two steps as a function of the exceeded acceleration limit values.

Abstract: For cornering identification in an anti-lock control system and/or traction slip control system, wherein the rotational behavior of the wheels is measured and evaluated to determine a vehicle reference speed, and wherein criteria for cornering identification are derived from the wheel slip, the slip signals of the individual wheels are filtered and the signals sent are compared. Cornering is identified when simultaneously the filtered wheel slip on both front wheels is in excess of a predetermined maximum value and the filtered wheel slip values of one rear wheel exceed and that of the other rear wheel fall below a predetermined value. The threshold values depend on the vehicle reference speed. The direction of cornering is also identified.

Abstract: 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.

Abstract: To improve the control behavior of an anti-lock control system or brake slip control system, more particularly, to improve the steerability of a vehicle and its drivability when braking during cornering is performed, criteria for cornering identification and for determining the direction of cornering are derived from the wheel slip of the individual wheels. When cornering is identified, the normal control mode which is intended for straight travel and is configured for an individual control of all wheels or an individual control of the front wheels in conjunction with a select-low control of the rear wheels is changed to a cornering control mode. In the cornering control mode, the average pressure level of the curve-inward front wheel is decreased by a predetermined value and the average pressure level of the curve-outward front wheel is increased by a predetermined value.

Abstract: To determine the pedal force as a control quantity for a brake system with anti-lock control, the drive motor of a hydraulic pump is switched over to generator operation during braking with anti-lock control, and the magnitude of the generator voltage and its fade-out behavior is evaluated. The hydraulic pump serves to return the pressure fluid which was discharged from the wheel brake for pressure reduction, or it serves for the supply of auxiliary pressure. The approximate supply pressure depending on the pedal force can be determined by the generator voltage and the fade-out behavior.

Abstract: A circuit configuration for detecting wheel sensor malfunctions includes circuits which process and analyze the sensor signals (s.sub.1 to s.sub.4), which ascertain the speed (v.sub.Rmax, v.sub.Rmin), deceleration and acceleration (a.sub.R) of the individual wheels and which compare these values with one another and compare them with predetermined threshold values (a.sub.0, v.sub.0, v.sub.1, -a.sub.1). Upon the detection of signals or combinations of signals typical of a sensor malfunction, the control will be disconnected after a predetermined period of time (T, T1+T2). When the measured acceleration values (a.sub.R) are below an overspeed threshold (a.sub.0) and the speed at any one of the remaining wheels is below a bottom speed threshold (v.sub.0), the control will be disconnected as soon as the speed of a wheel (v.sub.Rmax) exceeds a top speed threshold (v.sub.1). A time monitoring function is started in the presence of a measured acceleration value (a.sub.R) which is above the overspeed threshold (a.

Abstract: A circuit configuration for detecting wheel sensor malfunctions includes circuits which process and analyze the sensor signals (s.sub.1 to s.sub.4), which ascertain the speed (v.sub.Rmax, v.sub.Rmin), deceleration and acceleration (a.sub.R) of the individual wheels and which compare these values with one another and compare them with predetermined threshold values (a.sub.0, v.sub.0, v.sub.1, -a.sub.1). Upon the detection of signals or combinations of signals typical of a sensor malfunction, the control will be disconnected after a predetermined period of time (T, T1+T2). When the measured acceleration values (a.sub.R) are below an overspeed threshold (a.sub.0) and the speed at any one of the remaining wheels is below a bottom speed threshold (v.sub.0), the control will be disconnected as soon as the speed of a wheel (v.sub.Rmax) exceeds a top speed threshold (v.sub.1). A time monitoring function is started in the presence of a measured acceleration value (a.sub.R) which is above the overspeed threshold (a.

Abstract: A circuit configuration for detecting wheel sensor malfunctions includes circuits which process and analyze the sensor signals (s.sub.1 to s.sub.4), which ascertain the speed (v.sub.Rmax, v.sub.Rmin), deceleration and acceleration (a.sub.R) of the individual wheels and which compare these values with one another and compare them with predetermined threshold values (a.sub.0, v.sub.0, v.sub.1, -a.sub.1). Upon the detection of signals or combinations of signals typical of a sensor malfunction, the control will be disconnected after a predetermined period of time (T, T1+T2). When the measured acceleration values (a.sub.R) are below an overspeed threshold (a.sub.0) and the speed at any one of the remaining wheels is below a bottom speed threshold (v.sub.0), the control will be disconnected as soon as the speed of a wheel (v.sub.Rmax) exceeds a top speed threshold (v.sub.1). A time monitoring function is started in the presence of a measured acceleration value (a.sub.R) which is above the overspeed threshold (a.

Abstract: A circuit configuration for a brake system with anti-lock control and traction slip control comprising, wheel sensors for generating electric signals representing the wheel rotational behavior and circuits for the cornering identification is provided such that lateral reference speeds (13, 14) are formed by virtue of selection circuits (8, 9) which select leading wheel speed according to specific criteria, and by virtue of a filter means (10, 11) whose time constants (12) are variable. A difference signal (DVS) is formed of the lateral references speeds (SRG.sub.L, SRG.sub.R), the magnitude of which is variable by inverse feedback. This difference signal (DVS) serves to actuate an adaptation circuit (18) as a function of the vehicle reference speed (V.sub.REF). The adaptation circuit influences on the control thresholds of the anti-lock control and traction slip control to adapt the control to the particularities of cornering.

Abstract: 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.

Abstract: A circuit configuration for controlling the auxiliary-energy supply system of a brake system with anti-lock control and/or traction slip control. A volume pattern (VM) is created by measuring and evaluating quantities which determine the auxiliary energy requirement and, respectively, the pressure fluid flow. The volume pattern represents by approximation the pressure fluid discharge out of the master cylinder of the brake system as well as the pressure fluid requirement and is utilized for controlling the auxiliary-energy supply system (HEV). For forming the volume pattern (VM), a pedal force surplus (PKU) is definable which, in turn, is correlated with the initial gradient.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: A slip-controlled brake system for road vehicles in which one front wheel (VR, VL) and one rear wheel (HR, HL) at a time are connected to a common braking pressure control channel wherein the braking pressure variation in the two braking pressure control channels is influenced in dependence on predetermined selection criteria such as "select-low" and "select-high" criteria. A cornering identification circuit (20') is provided which adds up the slip values (S.sub.VL, S.sub.HL, S.sub.VR, S.sub.HR) of the two wheels of one side of the vehicle and compares them with the slip value sum (S.sub.L, S.sub.R) of the wheels of the other side of the vehicle. When the difference of the slip value sums of the two sides of the vehicle exceeds a limit value, the selection criteria and, hence, the braking pressure variations are temporarily changed. Because of the cornering identification circuit, it is possible to generate information about the driving direction, i.e.

Abstract: 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).

Abstract: In a brake-slip controlled brake system for automotive vehicles, each one front wheel and one rear wheel are assigned to one joint braking pressure control channel (6, 8; 7, 9). Sensors (S.sub.1 -S.sub.4) for determining the wheel rotational behavior are disposed at all wheels. After their electronic combination and processing, the sensor signals serve to govern braking pressure modulators, e.g. solenoid switching valves (6-9).In the presence of sufficient friction of the front wheels (V.sub.R, V.sub.L), brake slip control is dependent on the rotational behavior of the front wheels. In the event of too low friction, brake slip control is switched over to the rear wheels (H.sub.R, H.sub.L), preferably to the rear wheel having least deceleration which thereby takes the lead as regards the control of the further braking pressure variation.