Abstract: A traction distribution control system for a 4WD vehicle is so constructed as to carry out traction distribution control to increase distribution of traction to the driven wheels when a speed difference between the main driving wheels and the driven wheels exceeds a control threshold value, detect constant-speed run of the vehicle, and carry out correction control to correct the control threshold value in accordance with the wheel-speed difference when constant-speed run is detected.

Abstract: A traction distribution control system for a 4WD vehicle is constructed to calculate a difference gain in accordance with a difference in spinning state between main driving wheels, and determine a control signal for controlling traction distribution to driven wheels by multiplying a control amount by the difference gain.

Abstract: An apparatus for determining a road-wheel vibration for an automotive vehicle comprises wheel-speed sensors for detecting wheel speeds of each of road wheels, and a control unit which is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors.

Abstract: A four-wheel drive control system is provided which comprises a driving force distribution mechanism for transmitting a driving force from a power source to main driving wheels of a vehicle and capable of distributing the driving force to auxiliary driving wheels of the vehicle, a rotational speed difference detector for detecting a rotational speed difference between the main and auxiliary driving wheels, and a driving force distribution controller for controlling a distribution of the driving force to the main and auxiliary driving wheels on the basis of the rotational speed difference, wherein the driving force distribution controller determines a driving force to be transmitted to the auxiliary driving wheels on the basis of an output of the power source, a longitudinal load distribution in the vehicle and the rotational speed difference. A four-wheel drive control method is also provided.

Abstract: In anti-skid control system and method for an automotive vehicle, when a calculated wheel deceleration of any one of road wheels of the vehicle has reached to a predetermined deceleration set on the basis of a pseudo vehicle body deceleration calculated from detected road wheel velocities, an electronic control unit (ECU) suspends a pressure increase control such as to increase a brake liquid pressure of the road wheel corresponding one of wheel cylinders and executes such a pressure hold control as to hold the brake liquid pressure thereof.

Abstract: In a brake control apparatus for a vehicle, a left and right road friction coefficient estimating section calculates each of left and right estimated road surface friction coefficients from a relation between a pressure decrease control time in one cycle and a maximum wheel acceleration during the pressure decrease time. A split friction discriminating section discriminates a split friction road surface condition from a non-split condition in accordance with a difference between the left and right estimated road surface friction coefficients. A control modifying section modifies a brake fluid pressure control for a wheel cylinder to differentiate brake control characteristics for left and right wheels from each other in the case of the split friction road surface condition.

Abstract: An antiskid control system for a four-wheel-drive vehicle is arranged to calculate a difference between an average of wheel accelerations of front wheels and an average of wheel acceleration of rear wheels. When the difference is greater than or equal to the vibration determination threshold, the antiskid control system determines that a driveline vibration is generated and executes a control for converging the driveline vibration.

Abstract: In an antiskid brake control system, an ECU is constructed to calculate a pseudo vehicle-body speed in accordance with a sensed wheel speed, calculate a target wheel speed in view of a predetermined slip ratio obtained in accordance with a calculated pseudo vehicle-body speed, carry out pressure reducing control by reducing the fluid pressure within a hydraulic unit when the sensed wheel speed is smaller than the calculated target wheel speed, estimate an amount of fluid stored in a reservoir, and correct the target wheel speed to lessen the slip ratio when the estimated fluid amount is greater than a predetermined value.

Abstract: In an antiskid brake control system, an ECU estimates a wheel slip in accordance with a sensed wheel speed and controls a fluid pressure control valve for braking operation in accordance with the estimated wheel slip for an antiskid brake control, the fluid pressure being reduced when the wheel slip is enlarged and being increased when the wheel slip is lowered. When a vehicle-body speed is smaller than a predetermined quick pressure reduction prohibiting speed, the ECU performs a quick pressure reduction prohibiting control to restrain a quick pressure reduction having a greater reduction amount than a predetermined reduction amount.

Abstract: An anti-skid control system for an automotive vehicle includes a hydraulic modulator having electromagnetic solenoid valves for regulating a wheel-brake cylinder pressure at each of road wheels. A skid control unit prevents a wheel lock-up condition by controlling the wheel-brake cylinder pressure via on/off reaction of the solenoid valves in response to a pulse signal based on a wheel speed detected by a wheel speed sensor. The skid control unit has a data processing section that generates a desired wheel speed based on the wheel speed, calculates a desired brake-fluid pressure based on an integrated value of a wheel-speed deviation between the desired wheel speed and the wheel speed, sets a controlled ON pulse width based on the desired brake-fluid pressure, and outputting the pulse signal having the controlled pulse width to the solenoid valves after a lapse of a preset pulse width from a previous pulse signal output.

Abstract: There is provided a brake control system for carrying out ABS control in which the brake hydraulic pressure is reduced by a brake unit in accordance with a difference between a pseudo vehicle body speed and each of wheel speeds so as to prevent wheel locking. A control unit is configured to detect an abnormality in output of wheel speed sensors, and to determine the pseudo vehicle body speed in accordance with outputs from the wheel sensors except the wheel determined as being abnormal. The control unit determines whether the abnormal wheel is a drive wheel or a non-drive wheel, and to reset the determination of abnormality under conditions differentiated in accordance with whether the abnormal wheel is a drive wheel or a non-drive wheel.

Abstract: An automotive brake control system with an anti-brake skid (ABS) unit which controls a wheel-brake cylinder pressure to each individual wheel cylinder of the road wheels to prevent a wheel lock-up condition during braking, and an ABS control unit being configured to be connected electrically to at least wheel speed sensors and the ABS unit to execute skid control having at least a reduce-pressure operating mode and a pressure build-up operating mode, when the wheel speed sensor signals indicate that at least one of the road wheels is locking up. The ABS control unit includes a road-surface-condition change determination section which determines, based on both a time length of brake-fluid-pressure control continuously executed during the skid control and a recovery acceleration of the wheel speed of the road wheel subjected to the skid control, whether there is a road-surface &mgr; change from low-&mgr; road to high-&mgr; road.

Abstract: There is provided an automotive brake control system capable of executing ABS control (skid control), in which when an abnormality such as superimposition of noise on the output of a wheel speed sensor occurs, a pseudo vehicle body speed is generated by wheel-speed sensor signal excluding an abnormal wheel-speed sensor signal. The automotive brake control system includes an abnormality judgment section which determines whether an abnormal wheel-speed sensor signal is included in the wheel-speed sensor signals. The abnormality judgment section cooperates with a pseudo vehicle body speed generating section for generating a pseudo vehicle body speed based on the wheel-speed sensor signals except the abnormal wheel-speed sensor signal when the abnormality judgment section determines that the abnormal wheel-speed signal is present.

Abstract: A brake control system is constructed to obtain a pseudo body velocity in accordance with outputs of wheel-velocity sensors, to control said brake unit in accordance with a difference between each wheel velocity and the pseudo body velocity to reduce the pressures within wheel cylinders for ABS control, to determine that one of the outputs of the wheel-velocity sensors is abnormal when a pressure-reduction time measured during ABS control exceeds a predetermined value, and to form the pseudo body velocity, if an anomaly of one of the outputs of the wheel-velocity sensors is determined, in accordance with the outputs of the wheel-velocity sensors excluding the abnormal wheel-velocity sensor.

Abstract: An apparatus for determining a road-wheel vibration for an automotive vehicle comprises wheel-speed sensors for detecting wheel speeds of each of road wheels, and a control unit which is configured to be electrically connected to the wheel-speed sensors for processing a wheel-speed data signal detected from each of the wheel-speed sensors.

Abstract: Road wheel accelerations are calculated in a controller from respective road wheel velocity values. Any one of the road wheel velocities, including the road wheel velocity of one of the road wheels that is a controlled system in an anti-lock brake control during a brake operation, is selected on the basis of a predetermined condition, any one of the road wheel accelerations is selected from among results of calculations of the road wheel accelerations which corresponds to one of the road wheel velocities which is selected so as to generate a control-purpose road wheel acceleration, and anti-lock brake control is executed for each road wheel during the brake operation using the selected road wheel velocity and the control-purpose road wheel acceleration so as to prevent a wheel's lock for each road wheel from occurring.

Abstract: An automotive brake control system with an anti-brake skid (ABS) unit which controls a wheel-brake cylinder pressure to each individual wheel cylinder of the road wheels to prevent a wheel lock-up condition during braking, and an ABS control unit being configured to be connected electrically to at least wheel speed sensors and the ABS unit to execute skid control having at least a reduce-pressure operating mode and a pressure build-up operating mode, when the wheel speed sensor signals indicate that at least one of the road wheels is locking up. The ABS control unit includes a road-surface-condition change determination section which determines, based on both a time length of brake-fluid-pressure control continuously executed during the skid control and a recovery acceleration of the wheel speed of the road wheel subjected to the skid control, whether there is a road-surface &mgr; change from low-&mgr; road to high-&mgr; road.

Abstract: An automotive brake control system with an ABS system employing a hydraulic modulator, wheel-speed sensors, and a skid control unit. A vehicle deceleration &Dgr;Vi is calculated on the basis of a first speed V0 corresponding to the pseudo vehicle speed calculated at a time when the vehicle starts to decelerate and a second speed Vp corresponding to the pseudo vehicle speed calculated at a time when the pseudo vehicle speed is changed from an increasing state to a decreasing state at each cycle of the skid control, from a predetermined expression &Dgr;Vi=(V0−Vp)/T, where T denotes a derivative time.

Abstract: An automotive brake control system with an ABS system employing a hydraulic modulator, wheel-speed sensors, a longitudinal acceleration sensor, and a skid control unit. The skid control unit includes a lateral acceleration dependent offset-value arithmetic-calculation section which arithmetically calculates an offset value based on lateral acceleration exerted on the vehicle. Also provided is a pseudo-vehicle-speed compensation section which decreasingly compensates for a pseudo vehicle speed (an estimated vehicle speed value) by compensating for a signal value of input information data from the longitudinal acceleration sensor by the offset value based on the lateral acceleration exerted on the vehicle owing to the turn, when the vehicle is decelerating.

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.