Abstract: Anti-lock braking system for an automobile is disclosed. It includes a brake unit that can control brake pressures within wheel cylinders of each road wheels of the automobile separately. In an anti-lock control mode, a control unit is operative to determine a controlled wheel speed for a road wheel to be controlled. The control unit determines a slip of the road wheel based on the determined controlled wheel speed and activates the brake unit in a direction to decrease the determined slip. In determining the controlled wheel speed, the control unit is operative to select a higher one of actual wheel speeds of front and rear road wheels on the opposite side to the side where the road wheel to be controlled exists. Then, the control unit is operative to use, as the controlled wheel speed, a lower one of an actual wheel speed of the road wheel to be controlled and the selected higher one wheel speed.

Abstract: An antilock brake control system for a vehicle includes a PID calculating device for carrying out a PID calculation based on a deviation between a target slip rate determined based on a presumed vehicle speed and a slip rate, and the operation of a braking liquid pressure regulating device is controlled based on the result of the calculation in the PID calculating device. The PID calculating device is arranged to limit the PID calculation value within a predetermined limit value. Thus, it is possible to enhance the control followability in carrying out the control of a braking pressure based on the PID calculation.

Abstract: An antilock brake control system in a vehicle is designed to retard the pressure increasing timing in one of front and rear wheel braking liquid pressure regulating devices which corresponds to a wheel having a smaller load share, until the wheel speed of such wheel is started to be reduced while following an actual vehicle speed after being restored to near the actual vehicle speed, when both of front and rear wheels are in antilock brake-controlled state.

Abstract: In an automobile having a pair of front wheels, a pair of rear wheels, a brake system for selectively braking each of the pairs of front and rear wheels, an engine, a transmission system including a speed change gear device for selectively providing a plurality of transmission gear ratios, a center differential device, a front differential device, and a rear differential device, the traction control device detects slipping conditions of each of the pairs of front and rear wheels, and controls the brake system so as to brake at least one of the pairs of front and rear wheels for execution of traction controls according to one of at least two separate traction control programs which are automatically changed over for execution according to selections of the transmission gear ratios of the speed change gear device for a relatively high speed driving or a relatively low speed driving.

Abstract: A brake control system which employs an antiskid control and wheel lock protection differential reference controller to provide antiskid and antilock brake control. The differential reference controller is capable of estimating both wheel velocity and vehicle velocity based on a single wheel speed sensor input. To reduce the effects of wheel speed noise, the differential reference controller estimates the wheel velocity and vehicle velocity by carrying out parallel processes using identical processing functions. The estimated wheel velocity and vehicle velocity are subtracted providing a differential output indicative of the slip velocity. Only unique parameters for each process, derived from physical constants, are different. In this way, the wheel speed noise is introduced into both processes and canceled when the results are subtracted to obtain the slip velocity.

Abstract: An automobile brake control system, which applies braking force commonly to both driving wheels and restrictively controls the braking force when a specified difference occurs between a wheel speed of the driving wheel and a vehicle speed estimated based on wheel speeds of the front and rear wheels, controls, when the vehicle is traversing a split surface road, the braking force based on a wheel speed of a specific one of the driving wheels which is suffering a road surface frictional coefficient greater than another driving wheel, and corrects the vehicle speed to a lower speed according to a difference in road surface friction coefficients at the driving wheels.

Abstract: An antilock brake control system in a vehicle includes a PID calculating device for carrying out a PID calculation based on a deviation between a target slip rate determined based on a presumed vehicle speed and a slip rate, so that the operation of braking fluid pressure regulating device is controlled based on the result of the calculation in the PID calculating device. In the antilock brake control system, a braking pressure control mode is decided based on the result of comparison of a PID calculation value calculated in the PID calculating device with a predetermined threshold value, so that the operation of braking fluid pressure regulating device is controlled in such control mode. When the amount of variation in PID calculation value within a predetermined time exceeds a predetermined value, a control mode different from a control mode decided from a current PID calculation value is selected.

Abstract: A circuit arrangement for a brake system with electronic brake force distribution control includes circuits which determine the deceleration of the rear wheels and the deceleration of a vehicle or a corresponding reference quantity. The discrepancy of the filtered rear-wheel deceleration from the vehicle deceleration is evaluated for brake force distribution control. To this end, an output signal is produced by way of a differentiator and integrator comparing the rear-wheel deceleration and the vehicle deceleration, and the output signal is evaluated for the control of the braking pressure in the rear-wheel brakes.

Abstract: The present invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling the braking force applied to each wheel of a vehicle. The braking force applied to each wheel is controlled on the basis of outputs of the wheel speed sensors and the vehicle speed estimation unit. A limit value is calculated to a difference between a first estimated vehicle speed calculated for a second wheel located on the right side of the vehicle and a left estimated vehicle speed calculated for a left wheel located on the left side of the vehicle. The calculation of one of the first and second estimated vehicle speeds is limited in response to the limit value, so as to keep the estimated vehicle speed calculated for one of the right and left wheels rotating at a relatively low speed to be greater than a value subtracting the limit value from the second estimated vehicle speed provided for the other one of the right and left wheels rotating at a relatively high speed.

Abstract: A method of an accurate detection of a spinning vehicle wheel. Observed wheel speeds are derived by measuring the speed of each wheel and the slowest speed is set as the slowest observed wheel speed. A maximum probable wheel speed is derived by multiplying the slowest observed wheel speed by the ratio of the maximum wheel speed to the slowest wheel speed for a given minimum turning radius. The maximum probable wheel speed is compared with an observed wheel speed and if the observed wheel speed is greater, the wheel is deemed to be spinning.

Abstract: The invention provides an ABS and/or ASC control system for motor vehicles, of the type having a sensor arrangement for detecting rotational wheel speeds, an analysis unit for the cornering recognition, and actuators for reducing the brake pressure on at least one wheel which is on the inside during the cornering in the case of a cornering recognition and an operated brake such that an ABS control is initiated on at the most one wheel. Cornering recognition is carried out by calculating an actual value proportional to the rear axle lateral acceleration from the difference of the rotational wheel speeds of the rear wheels and/or an actual value proportional to the front axle lateral acceleration from the difference of the rotational speeds of the front wheels.

Abstract: A control method and system for a vehicle anti-lock brake system to provide for recovery from premature activation of the vehicle anti-lock brake system. The control system includes a microprocessor and accompanying components to perform the control method steps of generating an input signal representing a vehicle wheel velocity, processing the input signal to determine a wheel slip duration, comparing the wheel slip duration to a slip duration threshold, generating a premature activation recovery control signal when the wheel slip duration fails to exceed the slip duration threshold, and performing premature activation recovery control of the anti-lock brake system in response to the premature activation recovery control signal.

Abstract: In a circuit arrangement for a brake system with anti-lock system and/or traction control with input circuits, output circuits, control circuits, monitoring circuits, comparator circuits and circuits for switching off the control in the event of a fault, a continuous monitoring of the control circuits and of the monitoring circuits is made possible. Both the control circuits and the monitoring circuits comprise watchdog circuits for processing a watchdog algorithm which tests the functioning of the control circuits and monitoring circuits and comparator circuits for comparing the results of the watchdog algorithms respectively processed in the watchdog circuits. The output circuits only enable the control if both the control signals output by the control circuits correspond to the corresponding signals of the monitoring circuits and the results of the watchdog algorithms respectively processed in the watchdog circuits correspond.

Abstract: An anti-lock braking system for a road vehicle having a plurality of hydraulically operated brake actuators, a plurality of control channels controlling the supply of hydraulic fluid to the brake actuators, an electrical supply and a hydraulic pump for supplying hydraulic fluid to the brake actuation circuit. The pump is driven by an electric motor energized by the power supply. The magnitude of the operating voltage at the pump motor is compared with a predetermined reference voltage. The physical demand upon the pump motor is reduced by inhibiting the control channels if the measured magnitude of the electric motor voltage is less than the reference value.

Abstract: In a method of controlling an anti-skid brake system for a vehicle having one modulator and two wheel speed sensors for each axle, when the vehicle brakes during running, for example, on a split road where surface friction coefficients on the right and left surfaces of the road are greatly different from each other or on a curved road where torque values of the right and left wheels are quite different from each other, in case that one of the right and left wheels which is lower torque is set in a pressure reducing mode while the other wheel which is higher torque of the road is in a normal service braking state, a retaining mode or a slow pressure reducing mode is selected to the braking pressure of the right and left wheels. Therefore, when the conditions of the right and left wheel are quite different from each other as mentioned above, the braking pressure is retained or is intensified slowly so as to secure its braking force and thereby shorten the braking distance of the vehicle.

Abstract: A method is provided for modifying anti-lock brake control to a vehicle braking on a surface having a split-mu to higher-mu transition. The time duration of the apply stage of an anti-lock brake system cycle is measured for the two front wheels. The measured apply stage durations are compared to a selected threshold. The transition from the split-mu surface to the higher-mu surface is detected when the apply stage duration for the lower-mu wheel exceeds the selected threshold. An increased brake pressure rate is applied to both front wheels when the split-mu to high-mu transition is detected.

Abstract: A brake unit for automotive vehicles with electric drive is configured in the shape of a multiple-circuit compound system consisting of hydraulic friction brakes of brake circuits (I, I', I", III, III', III") and of an electroregenerative brake system (circuit II, II', II"). In a vehicle with a driven and a non-driven axle, three brake circuits exist, one brake circuit of which (I, I', I") is comprised of a pedal-actuated hydraulic brake pressure master unit (2) and of friction brakes (3, 4) acting upon the non-driven wheels. The second brake circuit (II, II', II") which represents an electroregenerative brake system is directly or indirectly coupled to the brake pedal and acts upon the driven wheels. The third brake circuit (III, III', III") which is comprised of friction brakes (10, 11) also acts upon the driven wheels. The actuation of the wheel brakes (10, 11) is connected to the second and third brake circuits.

Abstract: A vehicle braking system comprising a controller responsive to wheel speed signals from at least two wheel speed sensors for sensing skid conditions of at least two wheels and for generating skid control instructions; a plurality of wheel brakes responsive to fluid pressure, hereinafter referred to as brake pressure, supplied thereto; a supply device, comprising a common supply valve, for supplying brake pressure to the brakes from a fluid pressure supply in accordance with a brake operating signal; and a skid controller controlled by the skid control instructions for controlling the brake pressure in a plurality of cycles each of which comprises a pressure reduction phase and a pressure increase phase, and a first comparitor to compare the co-efficient of friction of the lower friction surface with a predetermined threshold, and/or a second comparitor to compare the relative values of the co-efficients of friction of the surfaces with which at least two of the wheels are engaged and a device to operate the s

Abstract: A system is provided for modifying anti-lock brake control to a vehicle braking on a surface having a split-mu to higher-mu transition. The time duration of the apply stage of an anti-lock brake system cycle is measured for the two front wheels. The measured apply stage durations are compared to a selected threshold. The transition from the split-mu surface to the higher-mu surface is detected when the apply stage duration for the lower-mu wheel exceeds the selected threshold. An increased brake pressure rate is applied to both front wheels when the split-mu to high-mu transition is detected.

Abstract: A circuit configuration and method for a traction slip control system which evaluates the speed (v.sub.ER) measured at a driven spare wheel with a correction factor K(t) in order to maintain or improve the control function even when a smaller size spare wheel has been mounted. This correction factor (K(t)) is determined by axlewise comparison of the rotating speeds (v.sub.na1, v.sub.na2 ; v.sub.a, v.sub.ER) of the wheels of one axle and by comparison of the speed differences measured on the driven and nondriven axles, with traction slip control being inactive. Upon transition from a very slippery road surface (.mu..sub.low homogeneous) to a dry road surface (.mu..sub.high homogeneous), without any prior determination of the correction factor, the slip threshold (S) is raised temporarily. When starting with different right/left friction coefficients (.mu.-split), with the spare wheel being mounted on the high friction coefficient side, a higher slip threshold (S.sub.ER) will be effective for this spare wheel.

Abstract: A vehicle brake system is described in which a lower brake pressure is fed in at the rear axle compared with the brake pressure of the front wheels. For the purpose of feeding in this brake pressure, the difference VD between the fastest front wheel speed and the slowest rear wheel speed is formed and compared with a threshold value which depends on the vehicle deceleration. An increase in pressure is undertaken until the threshold value is reached. The threshold value is, furthermore, larger in the case of travel in a straight line than it is in the case of travel in a curve.

Abstract: In an antiskid brake system for a vehicle, a wheel speed sensor detects the wheel speed of a wheel of the vehicle, a valve unit controls the braking pressure applied to the wheel and an electronic control unit effects an antiskid control in which it causes the valve unit to periodically increase and reduce the braking pressure applied to the wheel on the basis of the wheel speed of the wheel. The electronic control unit compares the wheel speed detected by the wheel speed sensor with a reference value, determines that the antiskid control has terminated when the former is lower than the latter, detects the condition of the road surface the vehicle is running and makes lower the reference value as the condition of the road surface is more apt to cause the wheel to skid.

Abstract: A pressure build-up pulse is provided at the brake of a driven wheel each time slippage of the driven wheel exceeds one of a series of successively larger threshold values. Build-up pulses continue until the slippage falls below the last threshold value exceeded, and pressure reduction pluses are effected each time the slippage falls below a succeeding smaller threshold value. If the slippage does not fall below the last exceeded threshold value by a given time, a build-up pulse is initiated even if the next higher threshold value is not exceeded.

Abstract: A method and system for correcting an overestimated vehicle reference speed is presented. In one embodiment, speed, slip, and acceleration quantities are computed for at least one wheel of a vehicle. The speed, slip, and acceleration quantities are compared to selected speed, slip, and acceleration thresholds, respectively. A count is incremented if the quantities are consistent with at least one vehicle reference speed being overestimated. The existence of at least one overestimated vehicle reference speed is detected when the count attains a selected threshold. The vehicle reference speeds are modified when the overestimated vehicle reference speed is detected.

Abstract: A braking force control system of a vehicle includes a deviation reference control quantity determining device for determining an operation control quantity for the actuator on the basis of a deviation between a target deceleration determined on the basis of a quantity of operation of a brake operating member and a detected deceleration of the vehicle. In this control system, the level of operation speed is judged in accordance with whether or not the variation per unit time in quantity of operation of the brake operating member exceeds a preset value.

Abstract: An anti-lock braking system includes three integrated circuits (an integrated voltage regulator and two different microcontrollers) which perform different functions but share the tasks of detecting malfunctions and shutting down the system when malfunctions are detected. The two different microcontrollers perform different functions, have different circuitry, and execute different software. Typically, a first microcontroller receives wheel sensor signals, calculates wheel velocities and accelerations, and operates mechanical devices which control braking. A second microcontroller executes the main anti-lock braking software and determines from the velocities and accelerations when brakes should be released. All of the integrated circuits monitor each other and the other elements of the anti-lock braking system to detect malfunctions. Multiple shut down methods are provided so that a single chip failure can be safely handled.

Abstract: In the present invention, an estimated car body speed is obtained on the basis of the highest wheel speed selected from three wheel speeds including the lowest of the wheel speeds of left and right rear wheels and the wheel speeds of left and right front wheels. Because the car body speed is obtained on the basis of wheel speed selected by Select-High of three channels of wheel speeds of the two front wheels and wheel speed by Rear Select-Low, wheel speed of outer rear wheel, which is much higher than the speed of the gravity center of the car body when a car is turning, is excluded, and the estimated car body speed thus obtained is closer to the speed of the gravity center of the car body.

Abstract: In the anti-lock control system described, the beginning of control is made more difficult in order to screen out disturbances. This is achieved by forming the sum or the average value of the slip values of at least the wheels of the front axle and, for triggering control, entering this sum or this average value into the instability criterion.

Abstract: Brake wear between braking sites of a vehicle is equalized by measuring work performed at the braking sites, comparing the amount of work performed at each braking site with an average calculated for all braking sites, and increasing braking demand at any braking site performing less than the average amount of work.

Abstract: This is a circuit configuration provided for an anti-lock-controlled brake system and serving for processing sensor signals obtained by wheel sensors (5) and for generating braking pressure control signals. This circuit configuration contains two microcontrollers (1, 2) interconnected by data exchange lines (7). The handled signals are concurrently processed by the microcontrollers independently of one another and the exchanged signals are checked for consistency. A deviation of the exchanged signals which is due to malfunctions is signalized to a safety circuit (8) which, thereupon, interrupts the power supply to the solenoid valves (Ll . . . Ln). The monitoring signal (WD1, WD2) fed to the safety circuit (8) is a predetermined alternating signal in case of consistency of the exchanged signals and in case of proper operation of the circuit configuration.

Abstract: A hydraulic dual-circuit brake system for a road vehicle with front-axle/rear-axle brake circuit division has a tandem main cylinder as a brake device. The primary output pressure space of the cylinders is associated with the front-axle brake circuit, and the secondary output pressure space of the cylinders is associated with the rear-axle brake circuit. A pressure modulator adjusts the front-axle/rear-axle braking force distribution in the direction of an approach to the, in each case, ideal braking force distribution, as a braking-pressure actuator for the rear-axle brake circuit. The pressure modulator has a drive pressure space, by the charging of which with the output pressure of an auxiliary pressure source under solenoid valve control, a braking pressure which can be coupled into the rear-wheel brakes can be built up in an output pressure space of the pressure modulator.

Abstract: In a fluid-pressure control apparatus for anti-skid control apparatus, including a control unit for generating brake control signals corresponding to the rotational behaviors of the respective wheels and valve control signals on the basis of the 2 outputs of the wheel speed sensors; and fluid pressure control valves arranged in the respective brake conduit systems and operated by the valve control signals the brake control signals from the front wheels are preferentially used to those from the rear wheels as the valve control signals in the respective brake conduit systems, and when the brake control signal is generated fron any one of the front wheels, the fluid pressure control valve in the one brake conduit system to which the one front wheel belongs, is operated by using the brake control signal as the valve control signal; and when the brake control signal is generated from any one of the rear wheels, the fluid pressure control valve in the one brake conduit system to which the one rear wheel belongs, is

Abstract: The invention is directed to an anti-skid control system for controlling a braking force applied to a road wheel with a hydraulic braking pressure supplied to a wheel brake cylinder through a pressure control valve controlled by an electronic controller. On the basis of a wheel speed of the road wheel detected by a wheel speed sensor, the controller calculates an estimated vehicle speed and sets a reference speed on the basis thereof. In the controller, the wheel speed is compared with the reference speed, and in response to a result of comparison the hydraulic pressure supplied to the wheel brake cylinder is controlled by the pressure control valve. Through an adjustment by the controller, the hydraulic braking pressure is decreased in response to a change of difference between the wheel speed and the estimated vehicle speed for a certain period of time.

Abstract: An anti-skid control apparatus for a vehicle includes fluid pressure control valve devices arranged between a tandem master cylinder and the front wheels of the vehicle, and a control unit receiving outputs of wheel speed sensors to assess skid conditions of the wheels and to control the valve devices. The apparatus discriminates between "low side" and "high side" of the road by assessing skid conditions of either the rear wheels or the front wheels. The braking pressure of the rear or front wheel that is on the low side and that of the wheel connected diagonally to it are controlled in either a "select-high" or a "select-low" manner, and the pressures of the other diagonally opposite wheels are controlled in the opposite manner.

Abstract: A magnet valve safety check and fault indication integrator including a first comparator for selecting the highest axle speed of a vehicle, a second comparator for determining whether the highest axle speed is less than a preset speed, an indicator for indicating if the vehicle is stopped, a timer for determining if the vehicle has been stopped for a predetermined time, a first sensor for sensing a transition from a braking mode to a power mode, an inhibit device for inhibiting all magnet valve feedback faults when the vehicle is stopped and in a brake mode for a period longer than the predetermined time, a timer circuit for ascertaining if a wheel slip is not in progress for a certain time period, a check circuit for monitoring the magnet valve feedback to determine if the magnet valve is not in an application state, a magnet valve cutout device for holding a cutout request until it is reset by a station stop signal, an event recorder for indicating that the vehicle speed is not less than the preset speed, a

Abstract: In an anti-lock control method and apparatus for preventing locking of vehicle wheels during braking, a plurality of pressure increase rates are predetermined correspondingly to various friction coefficients for a road surface, one of pressure increase rates is selected based on an estimated friction coefficient estimated from vehicle deceleration for increasing brake hydraulic pressure, and if it is detected that a lower one of right and left vehicle wheel speeds has risen to vicinity of the vehicle speed for a predetermined time period, the road surface is judged to have sharply changed from a low valued friction coefficient to a high valued friction coefficient along with movement of an automotive vehicle and the selected one of the pressure increase rates is then changed for another one appropriated for the road surface having a high valued friction coefficient.

Abstract: An anti-skid control system for use in a motor vehicle having wheels whose rotational speeds are sensed by wheel sensors. The anti-skid control system decides the condition of the road-surface, on which the motor vehicle is running, on the basis of signals from wheel sensors. A reference speed is further calculated on the basis of the sensed speeds of the wheels symmetrically provided at the rear-right and rear-left sides with respect to the advancing direction of the motor vehicle. That is a selected one of an average value of the speeds of the rear-right and rear-left wheels sensed by the wheel sensors and the maximum one of the sensed rear-right and rear-left wheel speeds is selected in accordance with the decided road-surface condition. The reference speed is calculated on the basis of the selected one. A control unit of the anti-skid control system performs slip control of the wheels in accordance with the calculated reference speed.

Abstract: A brake and anti-skid control utilizing optical input sensors for determining wheel speed or position and suitable for aircraft use is disclosed. A valve control has a continuous source of pressurized hydraulic fluid, a hydraulically actuated wheel rotation brake device which responds to applied hydraulic pressure to apply a braking force to the wheel to arrest wheel rotation, a low pressure hydraulic fluid return, and a flow control servo valve interconnecting the source, the return, and the braking device for directing fluid from the source to the braking device when in a first state and for directing fluid from the braking device to the return when in a second state. Applied hydraulic pressure is monitored and if that monitored pressure exceeds a command pressure, further fluid from the braking device is diverted to the return.

Abstract: The anti-skid control system is provided with wheel velocity sensors only for the driving wheels and is capable of performing the anti-skid control through its accurate estimation of the vehicle speed and proper compensatory control even when sharp braking occurs immediately upon the release of the accelerator after the occurrence of acceleration slip. The anti-skid control system is capable of starting the anti-skid control with certainty even when the braking operation is not detected because of a failure in the operation of the brake switch. The system is provided with a fluid pressure generating device, a fluid pressure controlling device, a brake operation detecting device, an acceleration detecting device, a wheel velocity detecting device, a braking force controlling device, a first estimated vehicle speed setting device and a second estimated vehicle speed setting device.

Abstract: A method of controlling a braking hydraulic braking pressure for a vehicle wherein a reference deceleration is set corresponding to an amount of braking operation, a standard hydraulic braking pressure is determined corresponding to the reference deceleration and an amount of electricity corresponding to the standard hydraulic braking pressure is applied to an actuator so as to allow the hydraulic braking pressure to be fed to a braking unit in dependence on the amount of electricity applied thereto so that ideal control for the hydraulic braking pressure is performed in correspondence to the quantity of braking operation. An apparatus for controlling a hydraulic braking pressure for a vehicle wherein its structure is simplified so as to carry out the aforementioned method.

Abstract: A method of controlling the brake pressure in an antilock vehicle brake system in which rotational velocities of the vehicle wheels are measured and the brake pressure is modulated in dependence upon the retardation and the slip of a wheel on exceeding threshold values provides that for each braked wheel the difference between the vehicle reference velocity and a wheel reference velocity is determined for adjusting the length of the pressure maintaining or pressure diminishing phase in dependence upon the difference.

Abstract: A circuit configuration for a brake system including an anti-locking control system, wherein a balanced pressure course is attained in the rear wheel brakes through control according to the "select-low" principle. The circuit configuration is furnished with a supplemental circuit (8) comparing the rotating pattern of the rear wheels during the control and, upon detection of a brake moment difference (.DELTA.M) causes a brake moment correction. This correction can be achieved, for example, by prolongating (T.sub.p, T'.sub.p) of the pressure build-up pulses controlling the rise in pressure in the wheel exhibiting a lower brake moment.

Abstract: An antilock control device is provided with sensors for sensing wheel speed of each of wheels mounted in the vehicle and a calculator for calculating a highest wheel speed, a second highest wheel speed and a lowest wheel speed. The calculator has a step for detecting a condition such that a difference between the second highest wheel speed and the lowest wheel speed is greater than a first threshold and, at the same time, a difference between the highest wheel speed and the second highest wheel speed is greater than a second threshold, and a step for counting a predetermined time period. When the condition is detected for a period longer that the predetermined time period, the wheel with the highest wheel speed is identified as a small diameter wheel which should be inhibited from being used for calculation of the estimated vehicle speed.

Abstract: Torque proportioning between the front and rear wheels of a vehicle is achieved by controlling the speed of each rear wheel, via modulation of the hydraulic brake pressure of the rear wheel during braking, to be the same as the speed of the front wheel on the same side of the vehicle.

Abstract: An anti-skid control system for an automotive vehicle is provided with braking condition detectors for detecting at least a running condition of the vehicle in braking operation and producing a detected signal corresponding to the running condition. The detected signal is compared with a reference value to produce a braking condition signal. In response to the braking condition signal, selectively provided is one control mode of a simultaneous control mode for controlling simultaneously a braking force applied to both of a pair of right and left road wheels and an independent control mode for controlling independently a braking force applied to each of the right and left road wheels. Then, the braking force applied to the right and left road wheels is controlled in accordance with the control mode.

Abstract: In a vehicle having a pair of left and right coaxially disposed wheels operatively coupled together via a differential gear which serves to restrict an increase in the difference in rotational speed between the wheels, a method to carry out anti-lock control of both the wheels concurrently during braking operation by utilizing a higher one of the wheel speeds thereof. This enhances braking efficiency and only one control channel is required for the wheels.

Abstract: A method for determining an accurate vehicle speed, based upon the wheel speed data, for vehicle antilock systems in which the integrity of each individual wheel speed value is verified before including that wheel speed value in the reference speed calculation. Reference speed is then computed as a function of only those wheel speed values which have been successfully accepted into the calculation.

Abstract: An anti-skid control apparatus for a vehicle having a brake system in which the front wheels are diagonally connected with the rear wheels, including a fluid pressure control valve device arranged between fluid pressure generating chambers of a tandem master cylinder and the wheel cylinders of the front wheels and a valve apparatus arranged between the wheel cylinder of the front wheels and those of the rear wheels. Fluid pressure is supplied to the rear wheels in accordance with the lower one of the brake fluid pressure onf the front wheels controlled by the fluid pressure control valve devices. The measuring or judging results of the skid conditions of the front and rear wheels on the same side of the vehicle are logically combined with each other to control the fluid pressure control valve devices.

Abstract: A drive slip regulating system is described, in which the speeds of the drive wheels are compared with one another and as a function of the deviation .DELTA. v a set-point brake pressure is calculated, with which the excessively spinning wheel is to be braked. In the pulsed furnishing of the brake pressure, the valve opening times are calculated, taking the pressure buildup function into account, in such a way that the actual brake pressure corresponds to the set-point brake pressure.

Abstract: In a braking apparatus for use in a motor vehicle which supplies hydraulic pressure from a master cylinder to wheel braking cylinders for front-side and rear-side wheels, a braking force adjusting device is provided in common between the master cylinder and the front-side and rear-side wheel braking cylinders to adjust the hydraulic pressure to be applied to the front-side and rear-side wheel cylinders. A proportioning valve controls the hydraulic pressure to the rear-side wheel braking cylinder to become lower than the hydraulic pressure from the braking force adjusting device by a predetermined ratio. The proportioning valve is adapted to change the predetermined ratio in accordance with a control signal to prevent the rear-side wheel from locking. The control signal to the proportioning valve is determined on the basis of information representing an excessive degreee of braking force obtained in accordance with the states of the front-side and rear-side wheels during the braking operation.