Abstract: An activation signal of a pump of a braking system is created as a function of a pressure gradient, preferably from a pressure accumulator. In this context, the switched-on time of a pulse-width modulated signal within an activation clock cycle is varied, taking into consideration the accumulator pressure gradient, in order to activate the pump. This is done by addressing a switching arrangement by way of a control unit. Activation as a function of the pressure gradient can be accomplished alternatively to or in combination with activation as a function of the generator voltage of the pump motor.

Abstract: A brake system for (10) a vehicle having a brake booster (14a) with an output put rod (152a) for providing a primary piston (310) in a master cylinder (12a) with an input force to pressurize fluid which is supplied to wheel brakes (10a) of a vehicle to effect a brake application in response to an operator input force. The master cylinder (12a) has a first housing (202a) with a bore (202a) therein for retaining the primary piston (310) in a first pressure chamber (212a). The bore (202a) has a first compensation passage (206a) connected to a fluid supply (204a) and an outlet port (218) connected to the wheel brakes (10a). The primary piston (310) has a first position of rest whereby the first pressure chamber (212a) is connected to a fluid supply (204a) through the first compensation passage (206a). The brake booster (14a) has a second housing (102,104) with an interior separated by a movable wall (122) into a front chamber (108) and a rear chamber (110).

Abstract: When a normal braking is performed, a master cylinder (32) and wheel cylinders (44FR, 44FL, 44RR, 44RL) are set to a conducting state. When an emergency braking is performed, the master cylinder and the wheel cylinders are joined together so that a large brake force can be generated. If the wheel cylinders are connected to an accumulator soon after the emergency braking, an increase in the wheel cylinder pressure can be prevented. Even after the emergency braking, the wheel cylinders and the master cylinder are maintained in the conducting state while the master cylinder pressure is rapidly increasing.

Abstract: A brake system contains a safety mechanism which terminates an automatic brake upon detecting that unnecessary braking force is developed as a result of a failure in an automatic brake controller. In the event a braking output is developed when neither a brake pedal nor the automatic brake controller is operated, the safety mechanism determines the occurrence of an abnormality, and interrupts a communication between the master cylinder and the wheel cylinder while decompressing the oil pressure in the wheel cylinder by discharging it into a low pressure accumulator. The safety mechanism allows the automatic braking to be terminated, thus allowing a risk of a collision by a succeeding vehicle to be avoided and allowing a vehicle to continue running.

Abstract: A braking assembly for providing a braking force to a wheel brake of a vehicle based upon receipt of an electrical brake signal is provided. The brake assembly comprises an actuator including a motor that applies and releases a piston within an actuator body. The actuator is fluidly connected to a wheel brake whereby the wheel brake can be applied and released. A solenoid valve is interposed between the actuator and the wheel brake on a primary fluid path for opening and closing the fluid connection. A step piston is placed within a secondary fluid path between the actuator and the wheel brake and operates to momentarily increase fluid displacement applied to the wheel brake when the solenoid valve closed.

Abstract: A brake control device includes a pressurization device having a first pressurization device for pressurizing the brake fluid supplied to wheel brakes in response to the driver's operation and a second pressurization device for pressurizing the brake fluid supplied to the wheel brakes independently of the driver's operation; a first detecting device for detecting a displacement of an input member of the pressurization device or an output pressure of the pressurization device; a second detecting device for detecting the condition of the vehicle; and a control device for memorizing relationships between a driving signal of the second pressurization device and the displacement of the input member or relationships between a driving signal of the second pressurization device and the output pressure of the pressurization device as control maps corresponding to the variety of the condition of the vehicle and for controlling the driving signal of the second pressurization device on the basis of the control

Abstract: A brake pressure control device is described. The device includes a pneumatic brake booster which has at least two chambers that are separable from each other. At least one of the chambers can be operated as a low-pressure chamber and at least another one of the chambers can be oerated as a working chamber. The device further includes a master braking cylinder in which a master cylinder pressure is generated over the pneumatic brake booster, and a hydraulic unit, which is installed between the master cylinder and at least one wheel brake cylinder of at least one wheel. The hydraulic unit includes an arrangement of switchable valves as well as least one pump. A hydraulic boost of the brake pressure is achievable with the assistance of the hydraulic unit. A wheel brake cylinder pressure may be generated in the at least one wheel brake cylinder with the assistance of the hydraulic unit, the wheel brake cylinder pressure being greater than the master cylinder pressure.

Abstract: In a pedal assembly for a brake-by-wire vehicle braking system, feedback reaction means (10) is provided so that feedback to the driver through the pedal (3) provides comfortable feel, similar to the pedal feel achieved in a conventional hydraulic braking system fitted to a non-EBS equipped vehicle. The feedback reaction means may comprise a two-rate spring assembly (24, 26) or a variable rate spring assembly, in combination with a damper (40).

Abstract: A hydraulic brake apparatus is provided for increasing a braking force with a brake feeling similar to that during a normal brake operation, even if a brake pedal is operated during an automatic brake operation. A valve device having a spool is placed in a power piston and is transferred between first and second positions depending on the operation of the brake pedal. At the first position, a power chamber is at atmospheric pressure level, while at the second position a fluid communication is established between the power chamber and an auxiliary hydraulic pressure source. The spool is driven independent of the operation of the brake pedal. When a hydraulic pressure is applied to the spool, the valve device is switched to the second position, urging the power piston to advance, without transmitting the resultant force to the brake operation member. The driving device, when applied with no hydraulic pressure, retains the valve device at the first position.

Abstract: The invention relates to an electronically controllable brake booster with a vacuum chamber and a pressure chamber, which are separated from each other by a movable wall, a control valve arrangement which can be actuated by means of an electromagnetic actuation means, and by means of which a pressure difference between the pressure chamber and the vacuum chamber can be adjusted, with the control valve arrangement, as a function of a current flowing through the electromagnetic actuation means, assuming a holding position in which the current ranges between a higher value and a lower value without the control valve arrangement leaving the holding position, a first pressure changing position in which the current is higher than the higher value, and a second pressure changing position in which the current is lower than the low value, characterized in that upon a changeover of the control valve arrangement from the holding position into the first or the second pressure changing position, or upon a changeover from

Abstract: The present invention relates to an arrangement for actuating an automotive vehicle brake system of the type ‘brake-by-wire’, which comprises an actuating pedal and a travel simulator which cooperates with the brake pedal and whose simulator piston is in a force-transmitting connection with the actuating pedal and is preloaded by a spring, and which includes means of attenuating the movement of the simulator piston as a function of the actuating pedal travel. To achieve an effective attenuation, according to the present invention, the simulator piston (11) delimits a hydraulic chamber (12) which is connected to a second hydraulic chamber (4 or 14, respectively) by way of at least one variable flow resistance (16,17,18,19,20).

Abstract: An electrically controlled, decentralized control system in a vehicle having control modules, each of which is assigned a vehicle control element for actuation. The actuation is carried out as a function of a driver's input which is formed in each control module on the basis of sensor signals that represent the actuation of an actuating element by the driver. In this context, at least three sensors are provided for detecting the actuating signals, one actuating signal being supplied directly to each control module.

Abstract: An electro-hydraulic braking system of the type capable of operating in a braking-by-wire mode wherein hydraulic pressure is applied to braking devices at the vehicle wheels in proportion to the driver's braking demand as sensed electronically at a brake pedal, in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels by way of a master cylinder coupled mechanically to the brake pedal and in an ABS mode in which the braking pressures at the individual wheels are controlled in dependence, inter alia, on the detected rotational behavior of the vehicle wheels, and which includes a hydraulic travel simulator which is connected hydraulically to the master cylinder by way of an electrically controlled isolation valve for providing improved feel for the driver through the brake pedal in the push-through operating mode.

Abstract: A braking control apparatus for vehicles which is capable of generating a braking force in response to a pedal depression force to non-controlled wheels while continuing vehicle stability control. The apparatus generates a brake fluid pressure including a pedal input pressure in response to the pedal depression force and a servo pressure in response to a fluid pressure introduced from a pressure apply unit. A fluid pressure control apparatus supplies brake fluid pressure, an electric control unit controls the braking force of each wheel by driving, and a pedal input pressure estimate portion estimates the pedal input pressure. The electric control unit controls the braking force of the non-controlled wheels during vehicle stability control based on the pedal input pressure estimated by the pedal input pressure estimate portion of the electric control unit.

Abstract: An electric powered brake system (10) for braking road-engaging wheels of a motor vehicle. An ignition switch for turning a motor of the vehicle on and off also controls the application of electric power to the electric powered brake system. A control and method (FIGS. 2 and 3) for maintaining application of full electric power to the electric powered brake system when the ignition switch is operated from ON to OFF so long as at least one parameter (60, 62, 64, 66) related to a respective component of the vehicle and indicative of a need to maintain full electric power application to the brake system continues to exist and for discontinuing application of full electric power to the brake system when all of selected ones of several such parameters are indicative of lack of need to maintain full electric power application to the brake system.

Abstract: A braking pressure boosting device is suggested, in particular for automotive vehicles, which includes a boost sensor for sensing or identifying the point of maximum boosting of the braking pressure boosting device. By using the boost sensor, ad signal is generated reporting the point of maximum boosting. This invention permits the manufacture of high-performance braking force boosting devices requiring minimal space and opens up new potential for economizing.

Abstract: An electronically controllable brake actuation system for automotive vehicles includes a simulator interacting with the master brake cylinder, a pressure source drivable by an electronic control unit and by which wheel brakes of the vehicle are pressurizable, the wheel brakes being connectable to the master brake cylinder by at least one hydraulic connection that is closable by separating valves, a device for the identification of the driver's wish for deceleration, each one inlet and outlet valve connected upstream of the wheel brakes, and wheel sensors sensing the rotational behavior of the vehicle wheels. To improve the meterability of braking pressure of a system of the above type, especially in the range of low pressure values, the pressure source is configured as at least one continuously adjustable piston-and-cylinder assembly having a pressure chamber which is connectable to the master brake cylinder and the wheel brakes.

Abstract: In a brake system, a controller closes solenoid shut-off valves to shut off a communication between a master cylinder and wheel cylinders by pressing a brake pedal, and at the same time, drives a pump and controls the operation of brake fluid pressure control means to supply brake fluid through the pump to the wheel cylinders, thereby performing braking action. Idle travels of the wheel cylinders can be cancelled by the brake fluid from the pump, and a very short pedal stroke can be obtained. Since the brake characteristics are set by considering three factors, i.e. pedal characteristics, travel of a brake pedal, and deceleration (brake fluid pressure) of a vehicle, the brake system has a very short stroke of the brake pedal as compared to a conventional one and has optimal brake characteristics.

Abstract: A brake by wire system provides the capability of both travel and force sensors on a brake apply input member such as a brake pedal and also provides redundancy in sensors by providing the signal from a sensor responsive to travel or position of the brake pedal to a first controller and the signal from a sensor responsive to force applied to the brake pedal to a second controller. The first and second controllers are connected by a bi-directional communication link whereby each controller may communicate its received one of the sensor signals to the other controller. In at least one of the controllers, linearized versions of the signals are combined for the generation of first and second brake apply command signals for communication to brake apply units. If either controller does not receive one of the sensor signals from the other, it nevertheless generates its brake apply command signal on the basis of the sensor signal provided directly to it from the sensor.

Abstract: A vehicle brake system 10 has a brake pedal assembly 14, a sensor 18 or 22 for sensing effort applied to the brake pedal assembly and a brake actuator 26 for generating braking force to be applied to one or more brakes 12A-12D on the vehicle. The brake system further includes a position sensor for sensing a position signal, such as an adjustable brake pedal position sensor 40, a seat position sensor 42, a steering wheel position sensor 44, or a driver position sensor 46, which is generally indicative of the stature and/or comfort of the driver. The brake system further includes a controller 24 for automatically controlling the amount of braking force applied to the one or more brakes in the vehicle as a function of the sensed position. Accordingly, the brake system automatically adjusts the braking effort based on a sensed position signal.

Abstract: A brake control apparatus is provided with a simulator for applying a biasing force to a manually operated braking member of a vehicle in response to braking operation. A sensor detects conditions of the vehicle including a braking condition of the vehicle. A first biasing device applies a first biasing force to the manually operated braking member in response to braking operation, and a second biasing device applies a second biasing force, as well. Only one of the first and second biasing devices applies the biasing force to the manually operated braking member when a predetermined condition is detected by the sensor, while both of the first and second biasing devices apply the biasing forces in the normal braking operation.

Abstract: An electro-hydraulic actuator for a motor vehicle brake-by-wire brake system including a housing, a piston bore in the housing, a T-shaped piston in the piston bore, and an electric motor connected to the piston through a speed reducer. The T-shaped piston includes a disc-shaped head in the piston bore and a tubular stem perpendicular slidable in and out of the piston bore through a sealed guide in the bottom of the piston bore. The top side of the piston head opposite the stem constitutes a large effective area of the piston for rapidly expelling a relatively large volume of fluid from the piston bore in a low pressure interval of operation the actuator. When the fluid pressure in the piston bore exceeds a transition pressure, a transition valve opens a bypass passage to the piston bore behind the piston head so that the same fluid pressure reacts against the bottom side of the piston head around the stem.

Abstract: To apply hydraulic pressure to a wheel brake upon failure of a stroke simulator, a brake pressure control device for automotive vehicles is designed so that when a power pressure source is in the normal condition, fluid communication between the master cylinder and the wheel brake is interrupted and fluid communication between the master cylinder and the stroke simulator is established, thus causing the output hydraulic pressure of the power pressure source to be adjusted in response to a detection output of a master cylinder hydraulic pressure sensor, thereby applying the resulting hydraulic pressure to the wheel brake. In addition, the brake pressure control device is provided with a stroke sensor which detects a stroke of a brake pedal. When the stroke of the brake pedal exceeds a predetermined stroke, a simulator cut-off valve is closed to interrupt fluid communication between the master cylinder and the stroke simulator.

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 hydraulic brake system wherein a portion of a volume of a first fluid supplied to a steering system by a pump is selectively diverted to an actuator assembly for a master cylinder to develop an force for actuating a master cylinder to pressurize fluid which is supplied to wheel brakes. An electronic control unit (ECU) for the brake system receives a first input signal indicative of the flow of fluid from the pump in the steering system, a second input signal indicative of the input force applied by the operator and a third input signal indicative of the speed of the wheels of the vehicle for developing a pulse modulated operational signal. The electronic control develops an operational signal which is supplied as the pulse modulated operational signal to a magnetic responsive valve. The pulse modulated operational signal creates a variable orifice in the magnetic responsive valve to restrict the flow of the first fluid to the steering gear and increases the fluid pressure of the first fluid.

Abstract: Method of diagnosing a booster of a braking system including a brake operating member operated with a brake operating force, a master cylinder for producing a hydraulic pressure on the basis of an input force received from the booster as a result of boosting of the brake operating force by said booster, and a wheel brake cylinder which is activated by the hydraulic pressure produced by the master cylinder, to brake a vehicle wheel, wherein the booster is determined to be abnormal if the detected input and output of the booster do not meet a predetermined nominal relationship therebetween. Also disclosed is a diagnosing device capable of practicing the method.

Abstract: A secondary source of braking for large hydraulically braked vehicles utilizing the available power source (38) provided by typically available anti-skid and traction control braking systems. The anti-skid braking system is used to control the secondary braiding function in a manner optimal to the operating condition of the vehicle. Unique distinctive operating modes are used when the vehicle is either moving (79, 81, 83), or stationary (57, 59, 73). The advantages of the stationary mode are fast time response and high output pressure controlled with a minimum of pump operation and fluid movement. The advantages of the dynamic mode are the ability to modulate brake pressure in response to the driver's command.

Abstract: A pneumatic brake booster (10) has a booster housing (12), the interior of which is subdivided by at least one movable wall (22) into a vacuum chamber (24) and a working chamber (26). Projecting into the booster housing (12) is a control valve (28) which, after a response force acting counter to its operating direction has been overcome, controls a pneumatic pressure difference acting upon the movable wall (22). The control valve (28) is operable both by means of a mechanical input element (36) and, independently thereof, by means of an electromagnetic arrangement (48) comprising a coil (58) and an armature (50), which are displaceable relative to one another along the operating direction.

Abstract: The wheel speeds are measured and are transmitted to a control unit. The control unit calculates the wheel slip from the wheel speeds and determines a continuous correction value for the setpoint value of the wheel brake pressure from the wheel slip. Using the thus determined correction value, the setpoint value of the wheel brake pressure is continuously changed as a function of the wheel slip. The control unit contains an arithmetic circuit which determines the correction value for the setpoint value of the brake pressure from the wheel slip.

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 fail-safe system 2, in which the position of an actuating device 4 is measured by three sensors 8, 10 and 12 that operate independently of one another. The sensor 8 is directly supplied with energy by a first energy source 20, and the sensor 12 is directly supplied with energy by the second energy source 22 of the system 2. The sensor 10 is supplied with energy by the first energy source 20 or by the second energy source 22 via a diode circuit 14, 16 such that, if one of the energy sources 20 or 22 fails, two of the three sensors 8, 10 and 12 are still supplied with energy. A majority decision can be carried out in the microprocessors 32 or 34 if the signal of one sensor is lacking, wherein it can also be determined which of the energy sources 20 or 22 has failed.

Abstract: An inlet pressure effected by the driver is detected in the brake system, and a driver's wish value formed from this pressure is used as the basis for controlling the brake system. In the formation of the driver's wish value the measured pressure value is corrected according to control parameters including either status information for a return pump and associated values, or flow information such as volume change in the master cylinder.

Abstract: An electronic braking system for a vehicle wherein control of the vehicle brakes is achieved by the use of electric control signals generated at a brake pedal in response to a driver's braking demand and an electronic controller which is adapted to control the supply of fluid under pressure from a power source to the brakes in accordance with said electronic signals corresponding to the driver's demand, the system being adapted to raise the brake pressure to a first predetermined level(jump-in) at a prescribed level of initial brake pedal travel and to release the brake pressure (reverse jump-in) as a second predetermined level, which is lower than at jump-in. The jump-in brake pressure level can be arranged to be variable with vehicle speed. In some cases, the brakes are arranged to be prefilled to a low pressure at a low pressure at an early stage in the pedal travel and then maintained at that low level until jump-in is triggered, whereupon the braking pressure is raised to the jump-in level.

Abstract: A braking force control apparatus adapted to change a magnitude of a braking force produced in response to a braking operation based on a condition of the braking operation, and control a braking force in an appropriate manner meeting an operating feeling of a vehicle operator. The braking force control apparatus performs either a normal control to produce a braking force by a braking operation or a brake-assist control to produce an increased braking force larger than the braking force produced during the normal control. In the apparatus, a stroke sensor (299) detects a stroke amount (L) of a brake pedal (202). When a stroke amount (L) of the brake pedal (202) detected at a predetermined time (TST) after the normal control is changed to the brake-assist control is below a predetermined value (&agr;), the apparatus determines that a brake releasing operation is intended by the operator, and terminates the brake-assist control.

Abstract: A brake force control apparatus is provided which generates a brake force larger than that of a normal time when an emergency braking is required, and realizes an operational feel giving no incongruous feel. It is determined whether or not an emergency braking operation was performed in accordance with a master cylinder pressure PM/C and a rate of change &Dgr;PM/C thereof. A plurality of start conditions (100, 112, 118) are set by assuming various conditions. A brake assist control is started (114) when a start condition selected in accordance with a state of motion of a vehicle is satisfied.

Abstract: A brake force control apparatus which can quickly supply pressurized brake fluid to wheel cylinders immediately after a condition for starting a brake assist control is established. The brake force control apparatus has emergency brake determining structure for determining an emergency brake operation performed by a driver, a high pressure source for generating a fluid pressure which is higher than a fluid pressure generated by a master cylinder, and a supply for supplying brake fluid from the pump to a wheel cylinder based on the determination made by the emergency brake determining structure. Actuating structure is provided for actuating the high pressure source before the fluid pressure is supplied by the supply.

Abstract: This invention relates to an electro-hydraulic brake-by-wire system including a hydraulic pump and a plurality of valves to achieve a demanded braking force, and to achieve a desired brake pedal feel. The brake system includes a plurality of wheel brakes, a reservoir of hydraulic fluid, and a pump for selectively pumping hydraulic fluid from the reservoir and supplying pressurized hydraulic fluid to the wheel brakes for applying a braking force. The pump acts as a source of pressurized hydraulic fluid to the wheel brakes during normal brake apply, as well as during advanced braking functions as Antilock Braking (ABS), Traction Control (TC), or Vehicle Stability Control (VSC). An apply valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the pump to the associated wheel brake. A dump valve is associated with each of the wheel brakes for selectively permitting flow of pressurized hydraulic fluid from the associated wheel brake to the reservoir.

Abstract: The present invention relates to a hydraulic brake system for automotive vehicles operable by independent force which includes a master brake cylinder preceded by a hydraulic brake force booster that has a booster piston and a working chamber to which an auxiliary pressure source is connectable, wherein a valve device operable by way of an electromagnetic drive is provided which establishes a hydraulic connection between the working chamber and an unpressurized pressure fluid supply reservoir in a first switching position and a connection between the working chamber and the auxiliary pressure source in a second switching position. To ensure low-noise operation of the brake system and a sensitively controlled volume delivery of the pressure fluid, the valve device is provided with a slide valve (20) of analog operation.

Abstract: A brake system for motor vehicles with an adjustable pneumatic brake force booster includes a control valve which can be actuated by an electromagnet independently of the driver's actions. A brake pressure controller generates signals which serve to actuate the electromagnet. In order to be able to implement a quick-action, low-noise pressure regulating system at low cost, the brake pressure controller (8) is formed by connecting in parallel an electromagnetic control circuit (60) that processes the nominal brake pressure signal (Pnominal) into a first current value (IA) and a regulating circuit (70) that processes a control difference (&Dgr;P) formed from the nominal brake pressure signal (Pnominal) and the actual pressure signal (Pactual) into a second current value IB, with the output variable (Inominal) of the brake pressure controller (8) being formed by adding together the two current values (IA, IB).

Abstract: A vehicle brake system having a wheel brake and first and second conduits in fluid communication with the wheel brake. A master cylinder having an outlet is in fluid communication with the first conduit for supplying pressurized fluid to the first conduit. The brake system further includes an isolation valve movable between a first position, wherein fluid is permitted to flow from the master cylinder to the wheel brake via the first conduit, and a second position, wherein fluid is prevented from flowing from the master cylinder to the wheel brake via the first conduit. The isolation valve is preferably a pilot-operated valve movable between the first and second positions by a pressure differential between the outlet of the master cylinder and the pressure in the second conduit between the boost valve and the wheel brake. A source of pressurized fluid is in fluid communication with the wheel brake via the second conduit.

Abstract: When a stroke speed exceeds a reference value of a stroke speed threshold value, a solenoid is energized to tract an armature, thereby opening an atmospheric valve independently of the position of a plunger. Consequently, power pistons, together with an output rod, are moved forward by a thrust corresponding to a pressure difference between a constant-pressure chamber and a variable-pressure chamber to perform a full-power braking operation. A reaction-adjusting mechanism contributes to an improvement in safety by functioning in such a way that when the part of the reaction force from the output shaft that is transmitted to an input rod reaches a predetermined value, a boosting ratio is increased, so that the reference value of the stroke speed threshold value can be set high to prevent unnecessary braking.

Abstract: An electrically controlled brake system for a vehicle, wherein an electric control device of the system has a device for detecting a changeover of an ignition switch from an on-state to an off-state. The electrically controlled brake system also includes a device for detecting a depression of a brake pedal beyond a predetermined depth. The brake system has a device for counting a predetermined time duration when the ignition switch changeover detection device detects a changeover of the ignition switch from the on-state to the off-state. Furthermore, the electrically controlled brake system includes a device for shutting down the electrically controlled brake system when the time count device has counted the predetermined time duration and the brake pedal depression detection device fails to detect the brake pedal depression beyond the predetermined depth.

Abstract: A hydraulic brake system with electronic anti-lock control contains, as essential components, a pedal actuated brake pressure transducer (1), electrically actuated inlet and outlet valves (EV1 to EV4, AV1 to AV4), wheel sensors (S1 to S4) and an electronic control circuit (6). The brake pressure transducer (1) is equipped with one or more path sensors (5), for the direct or indirect determination of the pedal path (S). Interdependent with the current driving conditions, the brake situation and the pedal path (S), the anti-lock control is switched from a standard control mode into a safety control mode, which essentially permits only a brake pressure increase in the front wheels and a brake pressure decrease in the rear wheels during an anti-lock control procedure. A limit value (SpGrenz) of the pedal advancement is determined interdependent with the driving conditions and the brake situation, and upon exceeding such a switch over takes place into the safety control mode.

Abstract: A braking force control apparatus adapted to generate a braking force, which is larger than that generated in a regular case, when a predetermined braking operation is carried out, this apparatus aiming at preventing the occurrence of an unnecessarily large sensible deceleration during a low-speed travel of a vehicle. ECU (10) is adapted to judge whether or not an emergency braking operation has been executed on the basis of a master cylinder pressure (Pmc) and its rate of change (dPmc). When a judgement that an emergency braking operation has been carried out is given, a wheel cylinder pressure (Pwc) is quickly increased by supplying an accumulator pressure to the wheel cylinder. When a vehicle speed exceeds a predetermined level during the execution of the emergency braking operation, the wheel cylinder pressure (Pwc) is speedily increased (116, 118) by a braking assist regular control operation.

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: This relates to a brake force control apparatus that executes a brake assist control, which generates, when a driver performs an emergency braking, a brake force greater than that generated at a normal time. The brake force control apparatus is inhibited from being unnecessarily executed at the time of traveling a rough road or passing a step. When it is determined, based on an operation of a brake pedal, that an emergency braking is performed, it is determined whether the road on which the vehicle is traveling is a rough road (step 114). If the road is not rough, it is further determined whether the vehicle is passing a step (step 116). The brake assist control is executed only when it is determined that the vehicle is not passing a step (steps 118-126).

Abstract: The speed of a pump motor in a vehicle brake control system is controlled by comparing an actual pump motor speed to a threshold speed. The actual pump motor speed is determined by measuring the pump back emf while the motor is de-energized. If the actual pump motor speed is greater than the threshold speed, the motor remains de-energized. If the actual pump motor speed is less than the threshold speed, the pump motor is energized with a pulse width modulated voltage having a variable duty cycle and a variable frequency which are functions of the difference between the actual pump motor speed and the threshold speed.

Abstract: A system generates a brake pressure with a pump which delivers a volume into the chamber of a master brake cylinder and builds up a pressure which is used by at least one additional assembly, particularly a power-assisted steering system. The system has at least one distributing and throttling element for admitting a definable pressure to the chamber of the master brake cylinder and/or the additional assembly. The one or more distributing and throttling elements can be triggered, as a function of the brake pedal position and/or of driving condition values and/or of operating values of the vehicle, such that the chamber and/or the additional unit can be acted upon by a pump generated adjustable pressure.

Abstract: A brake control apparatus includes a first valve for opening and closing a main line, a pump having an inlet port and an outlet port to supply pressurized brake fluid to a point between the main line and the wheel cylinder, an auxiliary line Mfc connecting the inlet port of the pump to a master cylinder, a second valve for opening and closing the auxiliary line, a brake operation sensor for detecting the operation of a brake pedal, and an electronic controller which controls the first valve, the second valve, and the hydraulic pump. The electronic controller judges the need for brake assist control based on the detection by the brake operation sensor and controls the first valve, the second valve and the pump to perform the brake assist control. The electronic control unit also controls the duty ratio for the second valve based on the detection of the brake operation sensor.

Abstract: A brake force control apparatus having a pump for pumping up brake fluid from a fluid pressure passage connecting a master cylinder and a wheel cylinder is provided which can accurately detect an amount of brake operation intended by a driver during execution of a brake assist control. The brake assist control is achieved by supplying the brake fluid delivered by the pump to the wheel cylinder when an emergency brake operation is performed by a driver. The brake force control apparatus has a control signal generator and a fluid pressure controller. The control signal generator generates a control signal by compensating a decrease generated in the output signal when the pump pumps up the brake fluid from the fluid pressure passage. The fluid pressure controller performs the brake assist control by using the control signal.