Abstract: An anti-locking brake system for a land vehicle, which is set up in particular for traction control and vehicle dynamics control, comprises a pump (42) for actuating a wheel brake (37) which removes brake fluid from a brake pressure generating unit (31) and supplies it to the wheel brake (37), wherein a first valve arrangement (1) blocks in a non-actuated (normal) position (1.1) the connection between the brake pressure generating unit (31) and an input connection (42e) of the pump (42) and in at least one actuated position (1.3) establishes a primary flow connection (A), a first electromagnetic valve (50) establishes in a non-actuated position (50.1) the connection between an output connection (42a) of the pump (42) and the brake pressure generating unit (31), and blocks it in an actuated position (50.

Abstract: A brake control device for a vehicle controls a vehicle wheel by supplying a hydraulic pressure generated by a hydraulic pressure generating device to a wheel brake cylinder of the vehicle wheel when a brake operating member is not being operated. When the brake operating member is operated while the hydraulic pressure has been supplied to the wheel brake cylinder for the vehicle wheel, a hydraulic pressure control valve device for the other vehicle wheel is controlled for supplying the hydraulic pressure to a wheel brake cylinder for the other vehicle wheel. Therefore, the hydraulic pressure is supplied to the wheel brake cylinder for the other vehicle wheel as well.

Abstract: A wheelslip is calculated from wheel speed, recorded by speed sensors (6), by a controller (8). A pre-set value for the wheelslip is regulated by means of a proportional controller. Parallel thereto, a set brake pressure for the wheel brakes (3) is fixed, which is determined by the controller (8), by means of the instantaneous wheel torque (Mmomentan) transferred to the ground by the particular wheel (2).

Abstract: A method of employing a hydraulic unit of a brake system containing brake lines extending between a master cylinder and wheel brakes and valves which are actuatable by exertion of magnetic force and which have removable electrical coils and when unactuated assume their blocking position, including the steps of removing coils from the valves; connecting the hydraulic unit, toward the master cylinder or the wheel brakes, to an air source of adequately high pressure; switching the valves to their open position by the exertion of magnetic force of a permanent magnet; positively displacing the pressure medium contained in the hydraulic unit from the air source by air and caught.

Abstract: A vehicle traction control apparatus and method where an amount of pressure change of braking pressure is based on the amount of acceleration slip and the wheel acceleration. When the traction control is being performed and the braking force is being increased, an upper limit pressure increase amount of braking pressure is based on the engine revolution speed, and the estimated braking pressure, so that the calculated value is smaller if the revolution speed or the estimated braking pressure is greater. The upper limit pressure increase amount of braking pressure is corrected so that it is greater if the speed reduction ratio of the transmission is smaller. If the amount of pressure change of requested braking pressure is excessively high, and the amount of increase in braking pressure needs to be limited, the amount of pressure change of braking pressure is limited to the corrected upper limit pressure increase amount.

Abstract: An electric control apparatus of a brake is provided with a second reservoir, in which a brake fluid is stored in advance, separately from a control device of a brake hydraulic pressure. The second reservoir communicates with a pump, which is an original component of the control device, on the side of a suction opening of the pump through a second liquid passage equipped with a first on-off valve. A first liquid passage is equipped with a second on-off valve. The pump is operated with the first on-off valve being opened to supply a brake hydraulic pressure corresponding to the quantity of an operation of a brake pedal in a sate in which the second on-off valve is closed to a wheel cylinder as an electric control mode of a brake hydraulic pressure of an electronic control unit.

Abstract: A method for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes the following steps: identifying a driving situation on a roadway with sidewise different coefficients of friction and, when the driving situation is identified and traction slip is encountered on both wheels, decreasing the brake pressure of the driven wheel on the low coefficient-of-friction side. A device for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes a determining device for determining a driving situation on a roadway with sidewise different coefficients of friction, and a brake actuation control which decreases the brake pressure of the driven wheel on the low coefficient-of-friction side when the driving situation is identified and traction slip is encountered on both wheels.

Abstract: The present invention discloses a method for brake pressure adjustment of a wheel brake comprising the following steps: determining a preliminary nominal pressure gradient in a brake control, determining actuating signals for a hydraulic pump and/or at least one hydraulic valve for the adjustment of the nominal pressure gradient, determining the actual pressure by way of a pressure model, determining the slip of a driven wheel, comparing the actual pressure with a first threshold value that is lower than the maximum possible brake pressure, and comparing the wheel slip, if the wheel slip is a traction slip, with a second threshold value, wherein, if the actual pressure and the wheel slip exceed the respective threshold values, the preliminary nominal pressure gradient is raised. The present invention also relates to a corresponding device.

Abstract: A system and method of vehicle stability enhancement control during ABS operation, the method comprising the steps of determining whether ABS mode is active; determining whether VSE is required; calculating a target wheel speed for each wheel if ABS mode is active and VSE is required; calculating an adjusted wheel slip for each wheel by subtracting the wheel speed for each wheel from the target wheel speed for each wheel and dividing the difference by the target wheel speed for each wheel; and determining an ABS control mode for each wheel using the adjusted wheel slip. The method further provides the step of calculating the target wheel speed for each wheel, in which the step of calculating the target wheel speed for each wheel further comprises adding a VSE modification term for each wheel to the vehicle speed to calculate the target wheel speed.

Abstract: To improve the control behavior of an automotive vehicle control system, such as an anti-lock system (ABS), a driving stability control system (ESP, ASMS, DDC), etc., in a brake system which includes a master cylinder, inlet and outlet valves for pressure modulation, a low-pressure accumulator, and a hydraulic pump for returning the pressure fluid discharged, when a wheel becomes unstable and upon commencement of the ABS control, that branch of the control system to which the unstable wheel is connected is temporarily uncoupled from the master cylinder pressure (pHZ) or initial pressure by closing the pressure fluid conduit in the direction from the wheel brakes to-the master cylinder, and a relatively quick rise of the braking pressure and a quick approach of the wheel braking pressure to the master cylinder pressure (pHZ) and, thus, the wheel lock pressure level is caused by returning pressure fluid from the low-pressure accumulator into this branch.

Abstract: The invention relates to a hydraulic vehicle brake system (10), having a hydraulic pump (12) and a high-pressure hydraulic reservoir (22) for external-force braking, as well as a conventional master cylinder (28), which serves as a set-point brake force transducer for the external-force braking and serves the purpose of muscle-powered secondary braking if the external-force service brake system fails. To embody the vehicle brake system (19) with an active pedal travel simulator, the invention proposes connecting the master cylinder (28) to a low-pressure hydraulic reservoir (26) via a disconnecting valve (30) and to the high-pressure hydraulic reservoir (22) via a return valve (32).

Abstract: A motor vehicle brake system is provided having a defining unit for determining the driver's desire to brake, an observation unit for determining the desired vehicle handling and the actual vehicle handling, and a central controller which, as a function of output signals of the defining unit and of the observation unit, determines desired wheel quantities for wheel-selective controlling of the individual brake actuators of the vehicle wheels. The desired wheel quantities are the desired wheel force and the desired wheel slip. A force-slip controller mounted at the vehicle wheel is connected upstream of each brake actuator and receives as input signals at least the desired wheel force from the central controller, the desired wheel slip from the central controller, the wheel reference speed from the central controller, the measured actual wheel force, and the measured actual wheel slip or the measured actual wheel rotational speed, for calculating the actual wheel slip.

Abstract: A device for controlling the driving stability of a vehicle includes a detection device for detecting an operating condition of the vehicle, a device for building up braking pressure for at least one of the wheels, and an influencing device which influences the braking pressure of one or more wheels in dependence on the detected operating condition of the vehicle. The above device also comprises a starting device which activates the device for building up braking pressure in idle mode before the commencement of an operating condition which initiates influencing of the braking pressure.

Abstract: For the acquisition and evaluation of safety-critical measured quantities, for example, of yaw rates (GR) as an input quantity of an automotive vehicle control system, the measured quantities are produced by way of two measuring channels (M1, M2) which are independent of each other. One measuring channel (M1) covers the entire measuring range, and the other measuring channel (M2) is set to a partial measuring range. To identify errors, the output quantities of the measuring channels (M1, M2) are checked for correlation with the measured quantities acquired by the measuring channels and/or for plausibility of the measurement results.

Abstract: A brake fluid pressure control device including a power pump provided in a fluid supply line for discharging fluid into the main fluid line. An on-off valve is provided in the main fluid line upstream of the point at which the outlet circuit of the pump merges with the main fluid line. A fluid reservoir is provided in the fluid supply line upstream of the pump. For automatic braking, a changeover valve is changed over to supply fluid in the first chamber into the inlet port of the pump. When the automatic braking is off, the inlet and outlet ports of the pump are connected to the second and first chambers of the reservoir, respectively, to supply fluid into the first chamber.

Abstract: A braking device for a vehicle having an operational hydraulic brake system, and an electronically controlled brake system. The hydraulic brake system and the electronically controlled brake system act independently on a brake caliper of a hydraulic brake. The electronically controlled brake system independently controls the hydraulic actuator for applying a hydraulic pressure to the brake caliper with no interference between the brake systems, which increases the degree of freedom of electronic control of the brakes. A braking device is also applied in a vehicle having an ABS control device.

Abstract: An improved traction control system for a vehicle which ensures that when a driver has performed a voluntary operation to reduce the driven wheel speed during carrying-out of a traction control, a deceleration greater than required is avoided, thereby avoiding an uncomfortable feeling provided to the driver. The improvement to the traction control system includes a control unit for stopping the traction control in response to the driver's operation to reduce the driven wheel speed during carrying-out of the traction control.

Abstract: A parking braking system in a vehicle not having EBS wherein, for parking braking, the brakes are arranged to be supplied with actuating fluid from a pressure source under the control of a manually operated electrical device and wherein, upon selecting parking braking by actuation of the electrical device, the brakes are arranged to be applied and mechanically locked or latched in place.

Abstract: In a braking force control apparatus for realizing both of a BA control for generating a great braking force when an emergency braking operation is executed and an ABS control for restricting a slip ratio of a wheel, an interference between the BA control and the ABS control is prevented. It is determined whether or not the ABS control is executed with respect to at least one of front wheels (step 104) when it is determined that the BA control is started. In the case that the ABS control is executed with respect to at least one of the front wheels, it is determined that a large amount of hydraulic pressure is fed to a wheel cylinder of a rear wheel at the same time when the BA control is started, thereby starting a BA slope restricting control for restricting an inlet thereof (step 108). In the case that the ABS control is not executed in the front wheel, a normal BA control is started (step 106).

Abstract: When it has been determined that a termination condition of brake TRC control has been fulfilled, SM valves 50FL and 50FR and a motor 80 are continuously placed in an ON state, and along with this, SR valves 70FL and 70FR are switched off, and furthermore holding valves 46FL and 46FR and pressure-reducing valves 48FL and 48FR of driving wheels are changed from an on-off switching state to an ON state, and termination control is initiated. Because of this, high-pressure brake fluid on the wheel-cylinder 2FL and 2FR side is expelled via the pressure-reducing valves 48FL and 48FR by drive of the motor 80. Consequently, high-pressure brake fluid can rapidly be expelled immediately after brake TRC control, and along with this, oil-shock noise can be alleviated.

Abstract: A brake force control apparatus is provided that performs a brake assist control in which a brake force larger than that of a normal time is generated when an emergency braking is required in a vehicle, and prevents a change in a driving stability when an abnormality occurs in a vehicle characteristic changing control for maintaining the driving stability of the vehicle. When an abnormality is detected (steps 102, 106-114) in one of the vehicle characteristic changing controls, an increasing slope of a brake force of rear wheels is decreased (step 104) in the brake assist control. Alternatively, the brake assist control may be prohibited (step 140).

Abstract: A brake system of a vehicle for a vehicle behavior stabilizing control has a working fluid circuit including wheel cylinders, a pump to produce a raised pressure source of a working fluid without an accumulator, fluid flow control valves for selectively supplying the working fluid from the raised pressure source to each wheel cylinder for applying braking, and an automatic controller for controlling the pump and the fluid flow control valves, wherein the automatic controller starts to operate the pump when a first parameter suggestive of a first running condition of the vehicle increases across its threshold value and starts to operate the fluid flow control valves for the vehicle behavior stabilizing control when a second parameter suggestive of a second running condition of the vehicle increases across its threshold value.

Abstract: A method and a device for determining a quantity describing the brake circuit pressure, with which the brake circuit pressure is determined for a pressure buildup, in particular a pressure buildup independent of the driver, and also for a pressure reduction. In a pressure buildup independent of the driver, the delivery performance of the pump which delivers the brake medium and is detected with sensing means is taken into account in determining the brake circuit pressure. In a pressure reduction, the brake circuit pressure is determined as a function of a quantity which describes the brake circuit pressure to be expected after the pressure reduction.

Abstract: A method and a device for the open-loop control of a vehicle hydraulic braking system having an anti-lock braking system, the vehicle having two axles to which wheels are attached and having wheel brakes that are coupled to a pedal-actuated master brake cylinder via hydraulic lines in which valve devices are provided. When the anti-lock system is triggered at at least one wheel of an axle, an active brake-pressure buildup is carried out at the wheel brakes of the other axle in order to attain a fully developed deceleration of the vehicle. The initial pressure between the master brake cylinder and the valve devices is used as the control criterion for the active brake-pressure buildup. In response to the fulfillment of a switch-off condition for the fully developed deceleration, the fully developed deceleration is switched off using a delay ramp.

Abstract: A method and device for estimating pressure changes within a hydraulic system having a first reservoir and at least one second reservoir connected to the first reservoir via valves, including the following steps: (a) specifying a pressure differential between the first and second reservoirs; (b) calculating a volume exchanged within a specified time interval between the first and second reservoirs via the valve, on the basis of a value for the pressure differential that is valid at the start of the time interval; (c) calculating a volume to be exchanged between the two reservoirs to achieve equal pressures in them; (d) if the amount of the exchanged volume calculated in step (b) is greater than the volume to be exchanged as calculated in step (c), replacing the value of the exchanged volume with that of the volume to be exchanged; and (e) adopting the volume value obtained in step (d) as the change in the volume in the second reservoir and determining the pressure change in the reservoirs on the basis of

Abstract: A brake control apparatus for automotive vehicles is provided which has two separate hydraulic brake lines leading to wheel cylinders and performs a brake assisting operation to hold the wheel cylinder pressure higher than the master cylinder pressure in each of the hydraulic brake lines when a brake pedal is depressed by a vehicle operator. The brake control apparatus also includes a fluid pressure difference regulator which regulates a pressure difference between the two hydraulic brake lines so as to fall within a given allowable pressure range, thereby minimizing adverse effects on the brake assisting operation which are caused by electric and/or mechanical performance difference between the two hydraulic brake lines.

Abstract: A system for retrofitting a four-valve ABS system for traction slip control. According to the present invention, only the wheel brakes associated with the driven wheels are furnished with outlet valves apart from the prevailing electromagnetically operated inlet valves. A separating valve is additionally inserted into the brake line, and a self-priming return pump is used which additionally has a suction line to the brake line between the master cylinder and the separating valve. Preferably, the suction line is adapted to be closed by a hydraulic valve. The separating valve may also be replaced by a hydraulically operated valve version. The resulting advantage is that at most four additional solenoid valves are required for the entire brake system in order to realize traction slip control.

Abstract: In a brake apparatus provided with an actuator for controlling brake fluid pressure applied to a wheel cylinder, a non-return valve disposed in a conduit connected to a master cylinder so as to allow brake fluid to flow toward the master cylinder. The non-return valve includes a ball serving as a valve body which seats on a valve seat formed between a small diameter portion and a large diameter portion in the conduit. After the ball is installed in the large diameter portion of the conduit, an opening part of the large diameter portion is closed by a lid while limiting a movement range of the ball so that a center of the ball does not reach an axis of a conduit perpendicularly connected to the large diameter portion.

Abstract: A vehicle brake system which permits both anti-lock control and different controls of independent force braking operations. In an independent force braking operation, a starting brake pressure is built up in the return circuit in the wheel brakes by way of a precharging pressure generator and the pump and is modulated in the following control phase according to the control algorithms of the selected control. Interposed between the precharging pressure generator and the return pump is a change-over valve which has three switching positions, i.e., one closed, one open, and one throttled. The change-over valve adopts its open position in the filling phase and its throttled position in the control phase. It is so configured that the switching position is achieved as a function of the initial pressure in the inlet chamber but independently of the actuating force which actuates the valve.

Abstract: A braking hydraulic pressure control apparatus for a vehicle comprising switching valve capable of switching between communicating and shut-off states between a master cylinder and hydraulic passages, and between communicating and shut-off states between the master cylinder and open passages. A driving-wheel control valve is also provided for controlling hydraulic pressure in driving-wheel brakes, and pumps whose inlet ports are connected to respective reservoirs and whose discharge ports are connected to respective hydraulic passages. The open passages are connected to the inlet ports of the respective pumps to improve the ability to remove air from the hydraulic pressure system, and allow simpler air-removing equipment to be utilized. The switching valve comprise opened-type and closed-type electromagnetic valves. Opened-type electromagnetic valves are positioned between the master cylinder and the hydraulic passages.

Abstract: Hydraulic Brake System with a Device for Active Braking In order to enable a hydraulic brake system which has a self-priming return pump (14) to quickly fill the wheel brakes (5) in an active braking operation, the present invention discloses the provision of a pressure-volume converter (20) on the pressure side of the return pump (14). The converter (20) causes a large pressure fluid volume to be conducted into the brake line (4) to the wheel brake (5) concerned at a small delivery volume of the return pump (14). This is possible because a return pump can generate high pressure and, thus, produce a sufficient amount of force to displace a stepped piston which can then displace a large quantity of pressure fluid. To permit the development of a sufficient back pressure on the pressure side of the return pump (14), a pilot pressure non-return valve (19) is arranged in the pressure line (18) which extends in parallel to the pressure-volume converter (20).

Abstract: In controlling the operation of a powered brake system of a vehicle in which wheel cylinders of the brake system are supplied with brake fluid compressed by a motor powered pump under a control of an electric controller according to a stroke of depression of a brake pedal by a driver detected by a brake depression stroke sensor and a master cylinder pressure generated by the brake depression detected by a master cylinder pressure sensor, a brake control device makes a double checking if the depression stroke detected by the sensor exceeds a predetermined threshold value, and also if the brake pedal is depressed at least for a predetermined stroke detectable by a stroke limit switch, before starting the operation of the powered brake system. When the stroke limit switch has failed, instead, the brake control device checks if the master cylinder pressure increases to a predetermined value to start the operation of the powered brake system with an initial biasing reduction of the starting brake force.

Abstract: A brake system including a master cylinder for generating pressurized fluid, a wheel brake in fluid communication with the master cylinder, and a first valve for regulating the flow of fluid between the master cylinder and the wheel brake. The brake system further includes a pedal travel simulator including a housing having a bore formed therein. A piston is slidably disposed in the bore. The piston and the housing generally defining a fluid chamber which is in fluid communication with the master cylinder. The pedal travel simulator further includes a spring which biases the piston in a direction so as to contract the fluid chamber. The brake system further includes a source of pressurized fluid and a boost valve which is in fluid communication with the source of pressurized fluid and the wheel brake.

Abstract: An improved traction control system in which a wheel spin condition is detected based on measured vehicle acceleration instead of measured wheel speeds. An electronic controller detects a wheel spin condition by computing the acceleration of the vehicle drive shaft and comparing the computed acceleration to an acceleration threshold stored as function of vehicle speed and wheel torque. If the computed acceleration exceeds the threshold for more than a predetermined time, the engine torque is reduced in relation to the amount by which the computed acceleration exceeds the threshold. When the computed acceleration falls below the threshold, the torque reduction is gradually removed. The wheel torque, vehicle speed and drive shaft acceleration are easily determined and filtered, and the incremental cost of the traction control function is primarily related to the memory requirements to accommodate the acceleration threshold look-up table.