Abstract: A failure diagnostic unit (144) obtains a control value for controlling an actuator (20) from each of a first processing circuit (11) and a second processing circuit (12) that are duplicated processing circuits. In a case where a first control value that has been obtained from the first processing circuit (11) does not match a second control value that has been obtained from the second processing circuit (12), the failure diagnostic unit (144) compares a state normal range with at least either the first control value or the second control value, and determines which of the first processing circuit (11) and the second processing circuit (12) an abnormality has occurred in, the state normal range being a range of a normal value of the control value that is estimated from a current operation state of a higher-order system that includes the actuator (20).

Abstract: The invention relates to a hydraulic brake system comprising a master brake cylinder the at least one working chamber of which is connected to the wheel brakes of the vehicle via at least one hydraulic line, the brake piston of at least one wheel brake being adjustable by a negative pressure in the hydraulic lines to produce a brake clearance.

Abstract: A system and method for increasing brake line pressure after brake booster vacuum has been exhausted is presented. In one example, brake line pressure is increased at a same rate after brake booster vacuum is exhausted as before brake booster vacuum is exhausted.

Abstract: To provide a vehicle provided with a valve-stop-mechanism-equipped internal combustion engine capable of ensuring a negative pressure in a brake booster while preventing with reliability fresh air from flowing into a catalyst during a valve stop control. An internal combustion engine provided with a valve stop mechanism capable of changing the operational state of an intake valve between a valve operating state and a valve closed/stopped state is provided. A brake booster is provided capable of assisting operation of a brake pedal of the vehicle. Exhaust side negative pressure passages are provided as communication passages that are configured to be in communication with each branch pipe section of an exhaust manifold in a period in which a negative pressure is generated in the case where the intake valve is in the valve closed/stopped state while an exhaust valve is allowed to open and close. The remaining end of the second exhaust side negative pressure passage is connected to the brake booster.

Abstract: Methods and systems are provided to reduce a hard brake pedal feel. A brake control variable is adjusted in anticipation of a hard pedal condition to increase hydraulic brake line pressure and maintain a normal pedal feel. A pedal force is inferred from brake line pressure relative to brake booster vacuum.

Abstract: A control device (10) for a brake-power-assisted brake system of a vehicle having a first input device (26) for a supplied first information item (28) relating to a supplied assistance force (Fu) of a brake booster (14) of the brake-power-assisted brake system, a second input device (30) for a supplied second information item (32) relating to a total force (Fg) comprising the assistance force (Fu) and a driver braking force (FI) supplied by activation of an activation element (12) of the brake-power-assisted brake system, an evaluation device (36) which is configured to define a third information item relating to a proportional relationship between the total force (Fg) and the assistance force (Fu) taking into account the first information item (28) and the second information item (32), and an output device (44, 50) which is configured to supply at least one control signal (46, 52) to at least one component (14, 54) of the brake-power-assisted brake system taking into account the defined third information ite

Abstract: An assistance-limit recognizing device for recognizing a limit of assistance made by a vacuum booster that is configured to assist an operating force applied to a brake operating member. A communication between a variable pressure chamber and a negative pressure chamber of the vacuum booster is established, when the operating force is not applied to the brake operating member. A communication between the variable pressure chamber and the atmosphere is established while the communication between the variable pressure chamber and the negative pressure chamber is cut off, when the operating force is applied to the brake operating member, whereby the operating force applied to the brake operating member is assisted based on a pressure difference between a pressure in the negative pressure chamber and a pressure in the variable pressure chamber.

Abstract: A system and a method for a controllable power-assisted application of pressure includes a force sensor capable of sensing a user-applied force; and a force generator responsive to the sensed user-applied force and capable of generating a force that is applied to a pressure-applying device. A force magnitude of the force applied to the pressure-applying device is based on a magnitude of the sensed user-applied force. One embodiment provides that the force applied to the pressure-applying device by the force generator exerts a predetermined amount of pressure against a surface. Another embodiment provides that the force magnitude is greater than a magnitude of the sensed user-applied force. Yet another embodiment provides that the force magnitude is proportional to a magnitude of the sensed user-applied force.

Abstract: In the hybrid vehicle of the invention, when the sum of a regenerative braking force BFr produced by a motor and an operational braking force BFpmc based on a master cylinder pressure Pmc is insufficient for a braking force demand BF* required by the driver in response to the driver's depression of a brake pedal, the motor and a brake actuator of an HBS are controlled to satisfy the braking force demand BF* by the total of the regenerative braking force BFr of the motor, the master cylinder pressure Pmc-based operational braking force BFpmc, and a compensated braking force BFpp based on a pressure increase by two pumps included in the brake actuator (steps S170 through S190).

Abstract: The invention relates to a hydraulic brake system comprising a master brake cylinder (4) the at least one working chamber of which is connected to the wheel brakes of the vehicle via at least one hydraulic line, the brake piston (12a-13d) of at least one wheel brake (RBi) being adjustable by a negative pressure in the hydraulic lines to produce a brake clearance (BLS).

Abstract: A braking apparatus includes a braking mechanism that increases operating force to a brake operating member by a brake servo, generates braking force exerted on wheels corresponding to the increased operating force, and is capable of holding the braking force when a vehicle stops, and a controller that executes braking force holding control to hold the braking force when an operation amount of the brake operating member corresponding to the operating force becomes larger than a control start judgment value, and sets the control start judgment value to be smaller than the control start judgment value in a normal state of the brake servo when the brake servo fails. The braking force can be appropriately held.

Abstract: In a negative pressure booster according to the present invention, a boot provided between a rear shell of a pressure chamber and an input shaft has a valve-body-side fixed portion at a position rearward of an accordion portion of the boot. The valve-body-side fixed portion is fixed to a valve body auxiliary member. An input-shaft-side fixed portion is provided at a rear end of the boot at a position rearward of the valve-body-side fixed portion, and the input-shaft-side fixed portion is fixed to the input shaft. Atmosphere inlet ports are formed radially on a side surface portion of the boot between the valve-body-side fixed portion and the input-shaft-side fixed portion, and a filter is stored in the boot between the valve-body-side fixed portion and the input-shaft-side fixed portion. Accordingly, an inflow noise of atmosphere is prevented, and a contamination removing function of the filter is satisfactorily maintained.

Abstract: A hydraulic brake device includes a cylinder, a larger diameter piston movable within the cylinder in response to operation of a brake booster power piston, a smaller diameter piston engaged with and movable relative to the larger diameter piston in response to movement of a brake operation member, a floating piston engaged with the smaller diameter piston and movable relative thereto, a first pressure chamber defined by the larger diameter piston and the smaller diameter piston, a second pressure chamber defined by the cylinder and the floating piston and hydraulically connected to a wheel brake, and a relief chamber defined by the cylinder and the larger diameter piston. A switching device is disposed between the larger and smaller diameter pistons for normally interrupting fluid communication between the first pressure chamber and the relief chamber and for establishing fluid communication therebetween when the larger and smaller diameter pistons are relatively moved.

Abstract: A vehicle motion control device which detects an abnormality of an automatic hydraulic pressure generator having a master cylinder, a booster which boosts the master cylinder and a booster actuator which actuates the booster irrespective of brake pedal operation and performs an appropriate transaction upon detecting the abnormality. The vehicle motion control device includes the automatic hydraulic pressure generator, a hydraulic pressure control valve disposed between the automatic hydraulic pressure generator and a wheel cylinder, and a controller performing the automatic pressure increase control by actuating the hydraulic pressure control valve and the booster actuator according to the vehicle running condition.

Abstract: In a braking system including a plurality of independently operable hydraulic brake assemblies, a controller is provided for monitoring the hydraulic pressure at at least some of the brake assemblies and for comparing that pressure with a brake control demand signal so that all or substantially all brake assemblies can be brought into operation if that comparison indicates a requirement for additional or full braking operation.

Abstract: A service brake for a vehicle, having two brake circuits which can be acted upon by pressurized fluid by way of a vacuum brake booster and a dual brake master cylinder, has at least one switchable device for changing the hydraulic pressure intensification by which, in the event of a failure of the brake booster, the pressure of the brake fluid is increased in each of the two brake circuits.

Abstract: The invention provides a real time process control system for control of machinery. The system has a master control module and a slave control module which receives control signals from the master control module. Both control modules send control signals to a control effector and cause changes in at least one effect causing quality of the control effector. The slave control module establishes a target value for the effect causing quality of the control effector based on the signal it receives from the master microprocessor. A sensor connected to the control effector and to the slave control module provides signals in the slave control module which indicate an actual value for the effect causing quality of the control effector. A feedback loop controls the control signal from the slave microprocessor to the control effector to adjust the value of its effect causing quality in accordance with the target value.

Abstract: The boosted brake system comprises two tandem master cylinders (15, 16), each controlled by way of the piston of a vacuum booster (10, 11) comprising at least two chambers, one (10) of these brake boosters being controlled by way of a pedal and comprising a valve mechanism making it possible to generate a difference between the pressures prevailing in the two corresponding chambers, and a reservoir (17) for feeding brake fluid to the associated hydraulic circuits the two chambers of one (10) of these boosters communicate respectively with the two corresponding chambers of the other booster (11), and the two hydraulic circuits (30, 32) associated with one (15) of the master cylinders communicate respectively with the two hydraulic circuits (30, 32) of the other master cylinder (16).

Abstract: A pneumatic brake booster (10) capable of operating without being actuated by a pedal (14), possesses at least one fixed part (36) and a control rod (12) with which the pedal cooperates (14). A sleeve (30) bears against the pedal (14) and partially surrounds the control rod (12), the control rod (12) possesses a shoulder (32) forming a stop cooperating with the sleeve (30) at rest and when the brake booster is actuated by the pedal (14), and the sleeve (30) is loaded by a spring (34) maintaining the pedal (14) at a given distance from the fixed part (36) of the brake booster (10) while the pedal (14) is not actuated.

Abstract: The present invention relates to a pneumatic brake booster assembly for a vehicle comprising a brake booster (10) formed from two shells (18; 37), a master-cylinder (14) mounted on the booster (10), a brake pedal (20) operatively linked to the booster (10) and mounted on a support bracket (22). According to the invention, one of the shells (18; 37) of the brake booster (10) is formed by a plate (26) upon which is mounted the support bracket (22), the plate (26) being destined to form a part of a firewall (12) of the vehicle.

Abstract: An arrangement for mounting a brake power booster to a splash-board of a motor vehicle is proposed, which brake power booster is actuatable by means of an operating rod and is provided in a booster housing with at least a first evacuatable and a ventilatable second working chamber, the splash-board separating the motor vehicle's passenger compartment from a mounting compartment of the brake power booster, preferably the engine compartment.

Abstract: A vacuum brake power booster for a slip-controlled hydraulic brake unit in which a major reduction of the costs of manufacture and of mounting and simultaneously an increase of its reliability in operation is provided. A first movable wall (7) within the booster housing is movable independently of the brake pedal input member (11) and a second movable wall (15) is provided at the first control housing part (52).

Abstract: An improved diaphragm is disclosed which partitions the interior of a shell of a brake booster into a constant pressure chamber and a variable pressure chamber. The diaphragm includes a bead which extends around its inner periphery, and which is formed with a lip extending from the side of the constant pressure chamber to the side of the variable pressure chamber. The lip is held in close contact with the outer peripheral surface of a valve body. The lip is capable of an elastic deformation in a flexible manner, whereby a good seal against the outer peripheral surface of the valve body is maintained.

Abstract: In an anti-lock automotive vehicle brake system comprising a vacuum brake power booster, a considerable reduction of manufacturing and assembling costs is obtained while the system's reliability in operation is simultaneously augmented by the incorporation into this brake system of a second movable wall arranged within the vacuum brake power booster to which a controllable pressure differential may be applied. The wall isolates two pneumatic working chambers and, in the case of slip control, is movable in a direction opposite to the actuating direction of the master brake cylinder by two compensating cylinders which are connected with the master brake cylinder pressure chambers. A hydraulic chamber which is normally in communication with an unpressurized pressure-fluid supply reservoir is sealed from the reservoir by a retention valve during slip control to hydraulically prevent brake petal induced pressure from being applied to the master cylinder.

Abstract: A brake system for automotive vehicles is disclosed comprising a vacuum brake force booster operatively located between a brake pedal and a master brake cylinder. The vacuum brake force booster includes at least two working chambers separated from one another by a membrane plate, one of the working chambers, through a master magnetic valve, being in communication with a vacuum source and the other working chamber being vented through a control valve acutable by the brake pedal to generate a brake force proportional to the brake pedal force. Connected to the master brake cylinder are brake circuits applying pressure to the wheel brake cylinders. Sensors associated with the wheels detect the rotational behavior of the wheels to identify a locking condition.

Abstract: To protect brake fluid against evaporation under extreme braking conditions, the brake fluid contained in the wheel brake cylinders is kept at a minimum pressure between 5 and 10 bar even after completion of a braking operation, thereby increasing the boiling point of the brake fluid. The wheel brake cylinders are designed as stepped cylinders with a counterpressure space, into which a likewise constantly kept counterpressure can be introduced, which maintains equilibrium with the admission pressure prevailing in the inlet pressure space of the respective wheel brake cylinder. A non-return valve arrangement, connected between the brake booster and the inlet pressure spaces of the wheel brake cylinders, blocks the return of the brake fluid to the brake booster when the pressure differential between the wheel brake cylinders and the brake booster drops below a threshold value P.sub.S.