Abstract: In a brake force control apparatus selectively performing a brake assist (BA) control for generating a brake force greater than that of a normal control time, an unnecessary restart of the BA control immediately after the BA control is terminated is prevented. The BA control is terminated when it is determined that an emergency braking is unnecessary since a master cylinder pressure (PM/C) has been reduced to a value less than a predetermined value. A restart of the BA control which is caused by a sharp change in the master cylinder pressure (PM/C) and a rate of change (.DELTA.PM/C) thereof due to a rapid decrease in a fluid pressure when the BA control is terminated is prohibited until a predetermined time has been passed after the BA control was terminated.

Abstract: A brake assist control for generating a brake force greater than that of a normal time is performed. It is determined (102) that a brake pedal is operated at a high speed when a rate of change .DELTA.PM/C of a master cylinder pressure PM/C exceeds a first threshold value .alpha.. When the cause of the braking operation is an external disturbance, the rate of change .DELTA.PM/C the rate of change .DELTA.PM/C changes immediately thereafter. When a period during which the rate of change .DELTA.PM/C becomes less than a second threshold value .beta. is shorter than a predetermined period T0, it is determined that the cause of the braking operation is the external disturbance such as a rough road or a step and an execution of the brake assist control is prohibited (104, 108, 110, 112).

Abstract: The invention relates to a method and device for controlling braking force distribution in a motor vehicle. In the case of failure of the braking system, the braking force distribution regulator enters emergency mode. The regulation is activated when the speed and the deceleration of the vehicle exceed given minimum values. The invention also concerns emergency measures for regulating the braking force distribution in the case of the certain individual errors.

Abstract: A vehicle hydraulic brake control system includes a wheel brake for applying a hydraulic braking force to a wheel in response to a hydraulic pressure supplied to the wheel brake, a reservoir is which is stored brake fluid under the atmospheric pressure, a main hydraulic pressure source fluidly connected to the reservoir for generating a high hydraulic pressure in response to a force applied to an operating member of the vehicle, and an auxiliary hydraulic pressure source fluidly connected to the reservoir for generating another high hydraulic pressure. A control valve is fluidly connected to the main hydraulic pressure source, the auxiliary hydraulic pressure source, the wheel brake, and the reservoir for establishing a supply and drain of brake fluid under pressure to the wheel brake from either the main hydraulic pressure source or the auxiliary hydraulic pressure source.

Abstract: In a hydraulic braking system, during normal service braking, the output from a master cylinder (3) is disabled and a brake (12) is applied from a high pressure hydraulic source (24) under the control of electric control means (30) including a solenoid operated actuator (6) responsive to electrical signals from a transducer (2) associated with the pedal (1), and upon failure of the electrical control means a direct flow path is defined between the master cylinder (3) and the brake (12) and through which the brake can be applied from the master cylinder by movement of the pedal in the "push through" mode.

Abstract: A method and an apparatus for controlling the brake system of a vehicle consisting of at least two component vehicles are proposed, where at least one of these component vehicles is equipped with an electrically controlled brake system. As a function of the actuation of the brake pedal, nominal values for the control of the wheel brakes are formed. An actuating variable for controlling the wheel brakes of the second component vehicle is formed in this first component vehicle. During a braking operation of the complete vehicle, the actuating variable for one component vehicle is modified by a value which, in the event that the brakes of the first component vehicle are not engaged, is determined by adjustment of the actuating variable for the second component vehicle or by adjustment of the nominal values for the wheel brake of the first component vehicle.

Abstract: In the case of a brake system for motor vehicles, having a brake pedal, a brake booster, a master brake cylinder and an electronically regulatable brake unit, which is arranged between the master brake cylinder and the wheel brakes and by which, via an electronic control unit, the brake pressure in the wheel brakes can be set independently of the preliminary pressure existing at the output of the master brake cylinder, when the brake booster fails, using the electronic control unit and the electronically regulatable brake unit, the brake pressure in the wheel brakes is generated such that a predetermined minimum desired deceleration course is obtained as a function of the pedal force applied by the driver by way of the brake pedal.

Abstract: A braking pressure control system comprises a braking pressure generator, a brake-actuating device for at least one vehicle wheel, a connecting line between the braking pressure generator and the brake-actuating device, a shut-off valve in the connecting line which has two switching positions, the connecting line being open in the basic position of the shut-off valve and the connecting line being closed or throttled in the switched position of the shut-off valve, including an outlet line which connects the brake-actuating device to a pressure fluid collecting means, an electromagnetically operated pressure-limiting valve in the outlet line, a wheel sensor which determines the rotational speed of the vehicle wheel and issues a corresponding sensor signal, and an electrical controlling and evaluating unit which has an input for the sensor signal and a first switching output to which a switching signal for the shut-off valve is applied, and a control output which issues a control signal for the current-supply ci

Abstract: A method and device for regulating the pressure in at least one wheel brake, such that a controller is provided for pressure regulation which forms at least one activation signal magnitude for a pressure-influencing valve arrangement on the basis of, among other things, a stored correlation between the activation signal magnitude and the pressure conditions at the valve arrangement. The method and device allow for the correlation to be adapted to changes to the braking system during operation.

Abstract: A hydraulic automotive vehicle brake system with brake slip control and automatic brake management for traction control and/or driving dynamics control includes a braking pressure generator which is hydraulically connectable to at least one wheel brake and a pressure fluid accumulator by way of pressure modulation valves, at least one pump which is connected with its suction side to a pressure fluid accumulator and with its pressure side to a pressure fluid conduit that extends from the braking pressure generator to the wheel brake, the pressure fluid conduit comprising the pressure modulation valves and a pressure sensor that is connected to the pressure fluid conduit in between the braking pressure generator and the pressure modulation valves. The pressure sensor is accommodated in a housing which houses the pressure modulation valves.

Abstract: A brake system with electronic braking pressure control, including a braking pressure generator, electrically operable hydraulic valves, and an electronic analyzing, is provided with an acoustic sensor which is used to determine the change-over behavior of the hydraulic valves for the approximate determination of the braking pressure prevailing in the braking pressure generator and/or in the wheel brakes. The measured pressure values, in the capacity of control quantities, are taken into account for braking pressure control or analyzed for monitoring purposes.

Abstract: Hydraulic pressure control apparatus wherein a pressure difference across a seating valve disposed in a fluid passage acts on a valve member for placing the seating valve in an open state, while an elastic member biases the valve member for placing the seating valve in a closed state, and a valve driving device operated with an electric current applied thereto generates a drive force acting on the valve member so as to open the seating valve. A control device for controlling the electric current includes a stepping controller for incrementing the amount of the electric current when the seating valve is operated from the closed state into the open state, such that an increment of the electric current decreases with an increase in the pressure difference. The hydraulic pressure control apparatus may be suitably used in a vehicle braking system, for controlling fluid pressure in wheel brake cylinder.

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 invention improves the time response of a secondary braking traction control system by utilizing stored fluid in the low pressure anti-skid braking system accumulators (34) to provide for faster build of pressure by the pump motor (38). Fluid is stored and utilized based on vehicle behavior and operational states and is based upon the principal the traction control, anti-skid braking and secondary braking requirements are generally mutually exclusive. This allows for a decreased response time of the secondary braking system and also provides for improved initial cycle response of typical traction control events that utilize the system configuration.

Abstract: The invention relates to an electronically controllable braking system for motor vehicles with a brake pressure generator unit (2) which can be actuated by a brake pedal (1), which supplies hydraulic fluid via a hydraulic fluid path (3) to at least one wheel brake (4) of the motor vehicle, a first electromagnetic valve arrangement (5a, 5b) which is arranged in the hydraulic fluid path between the brake pressure generator unit (2) and the wheel brake (4) for controlling the pressure build-up, pressure relief and pressure holding phases in the wheel brake, a motor-powered controllable hydraulic pressure source (7) which, in addition to or in lieu of the brake pressure generator unit (2), supplies hydraulic fluid to the wheel brake (4), and a motor-powered controllable auxiliary energy source (15, 30) which boosts an actuation of the brake pressure generator unit (2) by the brake pedal (1) or which effects an actuation of the brake pressure generator unit (2) in lieu of the brake pedal (1), with the controllable

Abstract: A booster and a pressure amplifying device are provided as devices performing a brake assist. Further a pressure sensor which detects master-cylinder pressure is provided. While the braking is applied to the vehicle, the malfunction of the booster can be detected based on master-cylinder pressure detected by the pressure sensor. If the malfunction of the booster is detected, a pump in the pressure amplifying device is driven as an substitute for the booster. As a result, a required brake assist can be performed to ensure high braking force. Accordingly, the brake control apparatus can enhance safety during vehicle operation.

Abstract: A brake system includes a controllable a pneumatic brake booster, whose control valve can be actuated independently of the driver's will by a solenoid. A control structure consisting of a brake pressure controller and a control valve positioning controller generate signals which represent the electrical current to be applied to the solenoid.

Abstract: A brake system control apparatus comprising: a fluid brake system including a master cylinder containing a hydraulic fluid having a hydraulic pressure, a hydraulic pump having an output hydraulically coupled to the master cylinder, a motor coupled to and providing motive force to the hydraulic pump, a current sensing device coupled to the motor and providing an output signal indicative of electric current through the motor; and an electronic controller coupled to the current sensing device comprising a first sampler taking a first sample of the output signal a first time period after a start up of the motor, a second sampler taking a second sample of the output current a second time period after start up of the motor and a divider for determining a ratio of the first and second samples wherein the ratio is indicative of a hydraulic pressure in the master cylinder at the start up of the motor.

Abstract: A simple, economical brake system for small front-wheel-drive vehicles. The brake system has a hydraulic service brake system for the front axle wheels and an electric service brake system for the rear axle wheels. The hydraulic service brake system has a pedal-actuated master cylinder, from which brake lines lead to hydraulic wheel brakes. There is one shutoff valve in each of the brake lines, and each shutoff valve is bypassed by a line to a pump that pumps pressure fluid from the corresponding wheel brake to the master cylinder. The shutoff valves and the pumps, together with an electronic control unit and sensors that monitor the wheel rotation performance form an anti-lock arrangement for the hydraulic service brake system of the front axle of the vehicle.

Abstract: In a selected operating situation, the automatic control circuit, which is closed during normal operation, is opened, the final control element of the wheel brake being actuated within the scope of an open-loop control process. The drive signal value for the wheel brake changes in accordance with a predetermined time function, and the application pressure or release pressure is found on the basis of the characteristic behavior of a value representing the braking action.

Abstract: A hydraulic bake system with electronic anti-lock control includes a multi-circuit braking pressure generator, electrically operable hydraulic valves, low-pressure accumulators which accumulate the pressure fluid that is withdrawn from the wheel brakes in the period of braking pressure reduction wheel sensors, and circuits are used to evaluate the sensor signals and to generate braking pressure control signals. The braking pressure in each wheel is controlled individually by the hydraulic valves. The filling ratio of the low-pressure accumulators or the residual volume is constantly determined and the pressure fluid discharge to the low-pressure accumulators is modified in the course of a control operation as a function of the length of the control and the filling ratio. Initially, there are no restrictions on the anti-lock function, while the rate of fluid flow is drastically reducted in the course of control.

Abstract: A wheel brake pressure supplying device for supplying fluid pressure for a wheel brake cylinder of a wheel on an automotive vehicle includes a reservoir, a pump, a motor, an accumulator connected to the wheel brake cylinder, a fluid pressure sensor, an electric source, an operation time determining device and a motor control device. The reservoir stores a fluid and the pump is connected to the reservoir for pumping fluid in the reservoir. The motor operates the pump and the accumulator is connected to the pump for storing the fluid pumped by the pump so that fluid pressure in the accumulator increases through operation of the pump. The fluid pressure sensor senses when the fluid pressure in the accumulator is less than a predetermined pressure. The electric source is connected to the motor for supplying voltage to the motor and the operation time determining device determines a target operation time of the motor based on the voltage of the electric source.

Abstract: A brake system control apparatus comprising: a sensor providing an output signal indicative of operator foot force on a brake pedal; an actuator coupled to wheel brake and controlling a wheel brake force applied by the wheel brake responsive to a control signal; a controller coupled to the sensor and the actuator and including a differentiator (60) receiving the output signal and determining a rate of change of the operator foot force on the brake pedal, a comparator (62) for comparing the rate of change to a predetermined minimum, wherein a rate of change above the predetermined minimum indicates a quick application of brake pedal force by the vehicle driver, a brake gain adjuster (64) for increasing a gain of the brake system when the rate of change is above the predetermined minimum, a brake command generator (72, 74) determining a control signal in response to the increased gain when the rate of change of brake force is above the predetermined minimum and responsive to a base gain when the rate of change

Abstract: An electronically controllable anti-lock brake actuation system for automotive vehicles, including a pedal actuated dual-circuit master brake cylinder, and braking pressure generators actuatable by an electronic control unit. Each of the braking pressure generators has a piston slidable in a cylinder bore from an initial position, each piston separating a first working chamber, to which each one wheel brake of the vehicle is connected directly and the master cylinder is connected by way of a closable hydraulic connection, from a second working chamber and is connected to the master cylinder where the stepped piston is operable to achieve a braking pressure generation or boosting.

Abstract: A pressure control apparatus is operated to connect a wheel cylinder to a reservoir via a return fluid passage so that brake fluid will be stored in the reservoir to reduce the pressure. In accordance with the operation of a fluid pressure pump, the brake fluid is discharged from the reservoir into the return fluid passage to supply the brake fluid to the wheel cylinder, so that the wheel cylinder pressure is gradually increased. Based on detection of a sharp decrease of the motor load, it is estimated that the reservoir has become empty. Then, brake fluid is taken from a fluid pressure generating apparatus into the wheel cylinder.

Abstract: A brake assurance module assures braking on at least one truck. It includes a summer, a level circuit, a delay circuit, an emergency driver, a valve driver and a timer circuit. The summer sums friction and dynamic braking signals into a total braking signal. The level circuit generates a threshold signal when the total braking signal exceeds a threshold. The delay circuit generates a level signal after having received the threshold signal throughout a preset time. When the emergency driver receives an emergency signal, it conveys a detect signal. The valve driver controls contacts each in series within a control line used to energize a valve whose operation is normally controlled by the brake control system. The valve driver when activated closes the contacts thereby permitting the system to control the valves. When deactivated, the valve driver opens them thereby preventing the system from controlling the valves. The timer circuit has set, trigger and reset inputs.

Abstract: A back-up power assisted braking system substitutes an intermittently actuated secondary source of pressurized hydraulic fluid such as a traction control/anti-lock pump and motor (41) for the normal braking power assist upon the detection of a failure in the primary power assisted braking system. A failure may be detected in responsive to sensing simultaneous brake pedal (23) displacement and a lack of fluid flow for providing an abnormality signal. Also, a failure may be detected by sensing a predetermined difference between the commanded braking force (45) and the actual braking forces (38, 49). There is a pressure transducer (45) which provides an indication of brake pedal commanded braking force and a hydraulic circuit (43, 53 or 55, 51) interconnecting the secondary source outlet, the individual wheel brake actuators (14) and secondary source inlet.

Abstract: A vehicle brake cylinder pressure control apparatus wherein an amount of fluid flow into a reservoir is estimated based on vehicle deceleration and a pressure reducing time of the brake cylinder, while an amount of fluid flow from the reservoir is estimated based on a pumping time during which the fluid is pumped up from the reservoir by a pump, and the vehicle deceleration or an operating speed of a pump motor, so that an amount of the fluid stored in the reservoir is estimated on the basis of the amounts of the flow flows into and from the reservoir. Various parameters may be used in place of the vehicle deceleration, pumping time and motor operating speed, for estimating the amounts of the fluid flow into and from the reservoir and the reservoir fluid amount.

Abstract: In a sensor malfunction detecting system, if an absolute value of a difference between acceleration values obtained from outputs of at least two of a pressure sensor a torque sensor, and a speed sensor, and an acceleration sensor is determined to be out of a range of a corresponding prescribed value then a corresponding count value is incremented by "1". The above described operation is repeated until the count value exceeds a prescribed target value whereupon it is determined that one of the sensors is malfunctioning, and a sensor malfunction signal is output. Accordingly, failure of a vehicle control system which controls braking force, for example, based on the output from the sensors can be prevented, which leads to improved safety during driving. Further, a sensor malfunction detecting system can be provided at a low cost.

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 braking force control system for a motor vehicle, in which a hydraulic pressure control device controls a hydraulic pressure generated by the master cylinder or the pump, in such a way that a target braking torque (Nr in FIG. 1) is calculated from a target slip factor (Sr) and an actual slip factor (S), the target braking torque (Nr) is converted into a target braking hydraulic pressure (Pr), and that an estimative braking hydraulic pressure (P) currently under action is calculated by the use of a hydraulic pressure model, while the controlled variable of the hydraulic pressure control device is calculated from the estimative braking hydraulic pressure (P) and the target braking hydraulic pressure (Pr) by the use of a reverse hydraulic pressure model. Thus, the hydraulic pressure can be controlled in conformity with the actual motion state of the motor vehicle.

Abstract: A power-assisted brake system which can be activated by a pedal including a travel simulator and a desired value transmitter which is coupled thereto and a second sensor which can be used alternatively as a desired value transmitter. The second desired value transmitter is a pressure transmitter. The signals of both desired value transmitters are monitored in an electronic control unit for essentially corresponding signal values. If there is an unacceptable difference in signal value, power-assisted braking operation is suppressed. Braking is then possible by an emergency brake cylinder. The power-assisted brake system can be used for motor vehicles for passenger transport and goods transport, in motor vehicles which are equipped with an anti-lock brake system (ABS) or with a traction control system (TCS).

Abstract: An anti-locking brake system is provided, wherein, during a control operation, the brake conduit is blocked by a separating valve. The wheel brakes, through a return conduit, are in communication with the intake side of a pump. Provided in the return conduit is an outlet valve. The pressure side of the pump, through a pressure conduit, is in communication with the brake conduit between the separating valve and the wheel brake. A restriction element is provided in the pressure conduit. Check valves between the master brake cylinder and the pressure side of the pump enable pressure fluid, if an enhanced amount of pressure fluid is required by the control circuit, to be fed from the master brake cylinder into the control circuit.

Abstract: Improvements in vehicle antilock braking systems of the type having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The improved system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration. This comparison normally invokes the enhanced anti-skid braking mode.

Abstract: A method for estimating hydraulic pressure in a control system that includes hydraulic pressure actuators (28,30) remotely situated with respect to a pressure source (14) wherein pressure at the remote location can be estimated thereby eliminating the need for using pressure transducers to obtain a pressure signal for use in an electronic controller (86,90,142) based on a calibratable relationship between estimated brake pressure and the difference in the volume of fluid flowing toward the pressure actuator and from the pressure actuator. An effective duty cycle for a solenoid operated fluid flow control valve (60,62) in the actuator circuit is determined in accordance with an empirical relationship between the difference between (i) the estimated brake pressure and the supply pressure and (ii) a commanded duty cycle.

Abstract: An antiskid control device which calculates an estimated fluid pressure of each of wheel cylinders under antiskid control in each control cycle so as to adjust a fluid pressure of each of the wheel cylinders on the basis of the estimated fluid pressure and behaviors of the wheels. The device includes a differential pressure detecting member which detects a difference between a fluid pressure of a master cylinder and the fluid pressure of each of the wheel cylinders so as to produce an output signal indicative of the difference between the fluid pressure of the master cylinder and the fluid pressure of each of the wheel cylinders. When the difference between the fluid pressure of the master cylinder and the fluid pressure of each of the wheel cylinders is found to be in the vicinity of zero, the estimated fluid pressure of each of the wheel cylinders is set to a predetermined value by stopping addition in calculation of the estimated fluid pressure.

Abstract: A process and system for attaining a desired braking value is disclosed. The actual braking value is adjusted until the desired braking value is attained. Conventionally the braking hysteresis worsens the response of a brake and, thereby, worsens the quality of the regulation of a braking system with regulated braking value. Known processes reduce the brake application energy in steps if the actual braking value is too great until the braking hysteresis has been overcome and the desired braking value has been attained. Whereas, the present invention decreases the brake application energy ZS by a value (HyS+W) consisting of the braking hysteresis HyS associated with the desired braking value and a effect drop-off W. This decrease occurs in the case of excessive actual braking value BI. The process accelerates the attainment of the desired braking value BS. The preferred area of application for the invention are braking systems in the automotive industry.

Abstract: Vehicle antilock braking systems having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration.

Abstract: A binary valve (40) for use in an anti-lock brake system having an electronic control unit (12) responsive to a wheel speed sensor (14) for optimizing the utilization of pressurized fluid to front (20,22) and rear (24,26) wheels during a brake application. The binary valve (40) is responsive to an input signal from the electronic control unit (12) derived by calculating when a complete stop (54) of a vehicle would occur and at approximately five seconds prior to such complete stop (54) decaying the fluid pressure supplied to the front (20,22) brakes to provide a transition (58) between the rate of deceleration (52) and a delayed complete stop location (56).

Abstract: An electronically controlled braking system having a driver operated control 11 for providing an electrical braking demand signal and a fluid pressure back-up supply; an electronic control 10, 139 is responsive to the electrical braking demand signal, and brake valves 12, 13, 14, 15 are responsive to an instructing signal supplied to the brake valves by the electronic control 10, 139 to control supply of fluid under pressure from a source 20 to at least one actuator 16, 17, 18, 19 for brake application. The fluid pressure back-up supply is also fed to the brake valve and a shuttle valve 134 is provided to feed the back-up supply to the actuator 16, 17, 18, 19 if the electronic control 10, 139 fails.

Abstract: A brake pressure control apparatus for regulating a brake pressure for braking a wheel of a motor vehicle, the apparatus including a device, for obtaining a wheel speed, a device for obtaining a reference wheel speed, on the basis of a vehicle speed, a commanding device for generating brake control commands for regulating the wheel brake pressure, and a pressure regulator for regulating the brake pressure according to the brake control commands, the apparatus further including an overshoot obtaining device for obtaining an estimated amount of an overshoot drop of the wheel speed, which overshoot drop is estimated to occur after commencement of a decrease of the brake pressure, so that the commanding device generates the brake control commands depending upon whether the wheel speed is higher or lower than a critical wheel speed, that is, the reference wheel speed minus the estimated amount of the overshoot drop of the wheel speed.

Abstract: In an antilock brake control system, a predetermined ratio of a pressure reduction threshold value to a pseudo vehicular body speed is varied in accordance with predetermined sections of a range of the pseudo vehicular body speed.

Abstract: In a motor vehicle brake system, a force increase gradient (Fv ped) at the brake pedal is determined and, in response thereto, the brake pressure is boosted in a manner which provides for successively associating respective threshold values (Fv max) with respective instantaneous force increase gradients (Fv ped) at the brake pedal during a braking operation. The instantaneous actual value of the force increase gradient (Fv ped) is compared with the respective threshold value (Fv max), and the brake pressure booster is controlled in response to the result of this comparison.

Abstract: A large articulated vehicle, such as a tractor semi-trailer truck often has a number of braking locations each having a number of brake sites. To properly balance the work performed at the various brake sites in decelerating the vehicle, it is necessary to determine the relative brake factors of each site. The brake factors characterize the braking performance for a particular delivered braking pressure. A system and method for determining the relative brake factors for such a vehicle is provided. The vehicle is decelerated at a known rate while delivered braking pressure is measured and recorded for each braking location. A system of simultaneous equations is then solved to determine the relative brake factors. Once the brake factors have been determined during a sequence of controlled braking events, subsequent braking may be modified to achieve a work-balanced braking mode.

Abstract: A method for detecting trouble in a fluid pressure system which has a fluid pressure source including a fluid pump, a pressure tank connected to the pump, a pressure detector for detecting fluid pressure in the pressure tank, and a control device for controlling the operation of the fluid pump on the basis of an output signal from the pressure detector, comprising the steps of operating such fluid pressure systems with output fluid pressure from the fluid pressure source, detecting variation in the output signal from the pressure detector and when the output signal is less than a first predetermined value during operation of the fluid pressure system driving said fluid pump regardless of the output signal from the pressure detector, and when the variation in output signal from the pressure detector is less than a second predetermined value as a result of such driving of said fluid pump energizing a signal to indicate that the system is out of order.

Abstract: An automatic brake control apparatus includes a pressure intensifying solenoid valve in a hydraulic brake line connecting a source of hydraulic pressure with a brake, as well as a pressure reducing solenoid valve in a relief line branched from the brake line and connected to a low pressure reservoir. A pressure sensor is positioned to sense a hydraulic pressure in the brake line at a position downstream of a point where the relief line branches from the brake line. A controller receives a signal from the pressure sensor and determines desired brake pressure for producing a desired speed reduction rate. The controller outputs control signals to the pressure intensifying solenoid valve and the pressure reducing solenoid valve such that the detected brake pressure corresponds to the desired brake pressure. The apparatus may be incorporated into a brake pressure control valve having first and second stages.

Abstract: A circuit configuration for a vehicle with electronic anti-lock control having circuits for individual control of the braking pressure variation in the wheel brakes of the wheels of one vehicle axle and for limiting the yawing moment owing to braking pressure differences. Circuits (6) detect the pressure reduction signals (PA1, PA2) individually per wheel and determine the pressure difference (DA12) from these signals. In the case of different friction values (.mu.-split situation), the mean pressure build-up gradient at the high-value wheel is varied as a function of the pressure difference (DA12) and the vehicle deceleration. At the time of the appearance of the peak yawing moment, namely directly before the low-value wheel will reenter the stable range, the braking pressure at the high-value wheel will be reduced by a value dependent on the vehicle deceleration and on the pressure difference.

Abstract: An antilock brake control apparatus is provided for adjusting the wheel cylinder pressure with actuators that include on/off-type valves. The antilock brake control apparatus includes wheel speed detectors for detecting the speed of each wheel, a wheel speed and estimated vehicle speed calculation device for calculating the wheel and vehicle behavior, and a locking symptoms detection device for detecting wheel locking symptoms and recovery from a wheel locking condition. A target pressure setting device for setting a target pressure, which is the estimated value of the wheel cylinder pressure during antilock brake control, based on a wheel cylinder pressure and a locking symptoms detection edge, is also provided. Further, a pressurization signal setting device for setting a pressurization signal used to drive the actuators based on the target pressure is provided.

Abstract: A brake fluid distribution control system for use in closed antilocking brake systems includes a switch in communication with low pressure accumulators for cyclically activating pumps that evacuate the low pressure accumulators of brake fluid under desired conditions. The method associated with this invention can be implemented by providing an indicator for indicating the amount of fluid within the accumulator and a switch for cyclically activating the pump when the fluid within the accumulator reaches a preselected capacity level. Alternatively, the antilocking brake system electronic controller is provided with appropriate software for cyclically activating the pump that evacuates the accumulators under preselected conditions.

Abstract: In an hydraulic braking system for vehicles solenoid-controlled valves are located in brake lines between the master cylinder and brakes on front and rear wheels of the vehicle. The solenoid-controlled valves are adapted to operate independently of each other to achieve independent pressure levels in the front and rear brakes by operation of a motor driven pump in response to signals supplied to an electronic control module from pressure sensing apparatus in each respective brake line.

Abstract: An electronic brake pedal adjustment apparatus has an apparatus for setting braking characteristics by which the driver can enter the relationship between the desired brake fluid pressure with respect to a given brake pedal effort, a detector for detecting an actual brake pedal pressure; and a computer for calculating a desired brake fluid pressure based on the set braking characteristics for the detected brake pedal effort. A brake fluid pressure control device is also provided so as to make the actual brake fluid pressure commensurate with the calculated brake fluid pressure. The relationship between the desired brake fluid pressure and the given brake pedal effort is shown on a display.