Abstract: In a method of improving the control behavior of a motor vehicle with anti-lock control, in particular for improving the brake performance on a homogeneous ground, where forces or pressures that act on wheels and tires are determined by sensors and used as control quantities for a motor vehicle control system, both front wheels are adjusted to their brake force maximums, and the front wheel with the lower instantaneously measured brake force or brake pressure is adjusted by a specific brake pressure build-up to its brake force maximum, whereas the other front wheel and the rear wheels are operated by means of a significantly decelerated brake pressure build-up.

Abstract: A detection device for detecting braking of a vehicle during cornering on a road surface where the coefficient of friction of the road surface on a wheel on the outside of a curve is lower than on a wheel on the inside of the curve includes a comparison device for comparing the brake force or the brake force reduction of at least one wheel on the outside of a curve with the brake force or the brake force reduction of at least one wheel on the inside of the curve, and a device for generating a detection signal or initiating appropriate measures when the brake force of at least one wheel on the outside of a curve is lower or reduced to a greater degree than the brake force of at least one wheel on the inside of the curve. A device for influencing yaw torques has a so-called detection device and a reduction device which reduces the brake force in a brake of a wheel on the inside of a curve.

Abstract: The sliding, integral, and proportional controller for providing aircraft antiskid braking control includes a reference velocity subsystem, a velocity error ratio subsystem, and a main controller subsystem generating a control command output signal indicative of a command braking pressure. The main controller subsystem includes a one dimensional sliding mode controller subsystem to determine an estimated net wheel torque signal, an adaptive threshold subsystem for generating an adaptive threshold based upon the modified slip ratio signal and a clock signal, integral gain subsystems, a proportional controller subsystem, and a pressure limiter. A method for determining braking efficiency of an aircraft braking system independent of the specific conditions is also provided.

Abstract: A traction control device for a vehicle that has at least one axle, to which two driven wheels are assigned, the traction control device, when one of the driven wheels of the axle shows a tendency to spin, regulating the kinematic behavior of the wheel tending to spin by building up a first wheel brake pressure such that the wheel tending to spin of the axle remains within a permissible slip range. In order to reduce disturbance torques caused by the first wheel brake pressure for a wheel that is not tending to spin of the axle, a second wheel brake pressure is built up, which is adjustable independently of the first wheel brake pressure. Also described is a method for controlling the slip of at least one driven wheel of an axle of a vehicle.

Abstract: A method for improving the traction between a road surface and a motor vehicle having a pair of front wheels and a pair of rear wheels which engage the road, each front wheel mounted on a front axle, each rear wheel mounted on a rear axle, one of the axles being a driven axle, and a two-part undercarriage roll stabilizer system including a front and a rear undercarriage stabilizer, each the undercarriage stabilizer comprising an actuating drive operatively coupled to a the pair of wheels, and for reducing the stopping distance along the road in which the motor vehicle can be stopped. The method includes: determining a coefficient of friction between at least two wheels and the road surface; comparing the coefficients of friction; and tensioning the actuating drives diagonally, the wheel contact forces between diagonally opposite wheels and the road surface thereby being one of increased and decreased in response to the determined coefficient of friction between a wheel and the road surface.

Abstract: A traction control system including engine intervention and brake intervention, during a start under &mgr;-split conditions the engine torque is increased compared to the driver input to accelerate vehicles as under high friction conditions, the vehicle acceleration under high friction conditions is determined, and engine torque is further increased by the brake torque applied to the low-&mgr; wheel.

Abstract: The present invention provides a method of estimating a coefficient of adhesion between a road surface and a plurality of tires disposed on a vehicle. An estimated coefficient of adhesion for each of the plurality of tires is provided. First values of longitudinal and lateral forces on the tires are determined from a first set of vehicle dynamic parameters requiring no explicit knowledge of the coefficient of adhesion; and second values of the same forces are determined from a second set of vehicle parameters in an analytic tire model including the estimated value of the coefficient of adhesion. Differences between the first and the second values of the forces on the tires are determined in the longitudinal and lateral directions. Longitudinal and lateral adaptation speeds are determined for each of the plurality of tires; and a coefficient of adhesion adjustment for each of the plurality of tires is estimated from the differences and the adaptation speeds.

Abstract: In an adaptive speed control system for a vehicle, a method and system for automatically adjusting a selected following interval for the vehicle based on driving conditions is provided. The method includes determining a driving surface coefficient of friction based on a driven wheel speed of the vehicle, and adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction. The system includes a receiver capable of receiving a signal indicative of a driven wheel speed of the vehicle, and a controller capable of determining a driving surface coefficient of friction based on the driven wheel speed, and capable of adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction.

Abstract: In a driving force control apparatus, a target driving torque TO is obtained based on a value determined by subtracting a feedback correction torque TF corresponding to a slip amount DVS from a correction reference torque TBC corresponding to a vehicle body speed VB. Slip is suppressed by a throttle control so that the engine output is reduced to the target driving torque TO. A retard command is output when the slip amount DVS and a slip rate GDVS are greater than predetermined values to retard an ignition timing of the engine, thereby suppressing an abrupt slip. When it is determined that a right and left front wheel speed difference is large and the vehicle is running on a split road, a retard command is made difficult to be reset as compared to a case where the vehicle is not running on a split road. When it is detected that the driving wheels are vibrating, particularly a differential factor is decreased and regulated only to a component to reduce the target driving torque.

Abstract: Upon detection of a potential transition from a low mu road surface to a high mu road surface, a rear wheel anti-lock brake system generates one dump pulse to increase the braking effort of the controller rear wheel as a test of the road surface. If the wheel accelerates following the test pulse, the transition is false and the anti-lock brake system continues as before. If the wheel does not accelerate following the test pulse, the transition is true and the anti-lock brake system proceeds to increase the braking effort of the controlled wheel brake.

Abstract: An antilock control method wherein during the running of an automotive vehicle on a road surface (&mgr;-split surface) having a different coefficient of friction where one of the right and left wheels of the same axle is on a road surface of the higher coefficient of friction and the other one of the wheels is on a road surface of the lower coefficient of friction, when the brake is operated and an antilock control starts, the wheel that runs on the road surface having the lower coefficient of friction excessively slips in a first cycle of the antilock control, and a predetermined condition is satisfied, 1) a hydraulic braking pressure to the wheel that runs on the road surface having the higher coefficient of friction is progressively decreased every period while changing a forcible pressure-decreasing time, and 2) after the pressure decreasing, another predetermined condition is satisfied, a gentle decreasing of the hydraulic braking pressure to the wheel that runs on the road surface having the higher coef

Abstract: An antilock control method wherein during the running of an automotive vehicle on a road surface (&mgr;-split surface) having a different coefficient of friction where one of the right and left wheels of the same axle is on a road surface of the higher coefficient of friction and the other one of the wheels is on a road surface of the lower coefficient of friction, when the brake is operated and an antilock control starts, the wheel that runs on the road surface having the lower coefficient of friction excessively slips in a first cycle of the antilock control, and a predetermined condition is satisfied, 1) a hydraulic braking pressure to the wheel that runs on the road surface having the higher coefficient of friction is progressively decreased during progressively decreasing periods of time, and 2) after the pressure decreasing, another predetermined condition is satisfied, a gentle increasing of the hydraulic braking pressure to the wheel that runs on the road surface having the higher coefficient of frict

Abstract: Provided is a braking force control apparatus for vehicles capable of performing appropriate vehicle braking even in a road-contactless state of a wheel. The braking force control apparatus is adapted to a four-wheel drive vehicle having a center differential for distributing and transmitting driving force to the front wheels and rear wheels and a braking system capable of exerting braking force on each of the front and rear wheels, based on voluntary switching between braking according to driver's brake-pedal actuation and forced braking independent of the brake-pedal actuation. It is determined whether the vehicle is in an engine brake state and it is then determined whether at least one of the wheels is in the road-contactless state.

Abstract: In an adaptive speed control system for a vehicle, a method and system for automatically adjusting a selected following interval for the vehicle based on driving conditions is provided. The method includes determining a driving surface coefficient of friction based on a driven wheel speed of the vehicle, and adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction. The system includes a receiver capable of receiving a signal indicative of a driven wheel speed of the vehicle, and a controller capable of determining a driving surface coefficient of friction based on the driven wheel speed, and capable of adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction.

Abstract: When carrying out automatic braking in order to avoid contact of a vehicle with an object, the behavior of the vehicle is prevented from becoming unstable due to abnormal road surface conditions in which the coefficients of friction of the road surface are different for the right and left wheels. An object which is present in the direction in which the vehicle is advancing is sensed by a radar device, and based on the sensing results if it is determined that there is a possibility of the vehicle making contact with the object, the automatic braking system operates the braking device at time t0 so as to carry out automatic braking.

Abstract: In order to adapt a simplified vehicle model to the driving behavior of a real automotive vehicle, it is possible to modify the slip rigidity values assumed to be constant in a linear model. After departure from the linear range of the lateral-force/slip-angle characteristic, a lower value can be assumed for the slip rigidities. However, this will involve the risk that the wheels of the rear axle are already in a slip angle range to which the lower slip rigidity is associated whereas the front wheels are still in the linear range of the lateral-force/slip-angle characteristic. This would impart to the vehicle model an oversteering behavior which should the more so be avoided if such a vehicle model is used for presetting the nominal value. This problem is solved, in the practice of the invention, by suggesting to modify only the slip rigidity values of the front axle while the ones of the rear axle are assumed to be constant.

Abstract: In an adaptive speed control system for a vehicle, a method and system for automatically adjusting a selected following interval for the vehicle based on driving conditions is provided. The method includes determining a driving surface coefficient of friction based on a driven wheel speed of the vehicle, and adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction. The system includes a receiver capable of receiving a signal indicative of a driven wheel speed of the vehicle, and a controller capable of determining a driving surface coefficient of friction based on the driven wheel speed, and capable of adjusting the selected following interval for the vehicle based on the driving surface coefficient of friction.

Abstract: An anti-lock braking system includes a friction torque gradient estimating unit for estimating, from a small number of parameters, the gradient of friction torque with respect to a slip speed, and controls a braking force acting on wheels on the basis of the friction torque gradient estimated by the friction torque gradient estimating unit. The friction torque gradient estimating unit may employ several types of estimating methods; e.g.

Abstract: A process for the braking of a vehicle on road surfaces with varying frictional values influences the respective braking forces on the wheels of at least one axle via a common braking value. The inventive process recognizes differences between these frictional values, and the common braking value is adjusted so that the wheel located on the surface with the lower frictional value is locked at least intermittently, while the frictional value of the other wheel can be utilized advantageously. The common braking value is reduced at predetermined time intervals, so that the wheel located on the surface with the lower frictional value can start up again from the locked state when an increase in frictional value occurs. Depending on the reaction of the wheel located on the surface with the lower frictional value, it is then possible to decide whether further locking of this wheel is acceptable, or must be terminated because of anticipated damage to the tire, or reduction of travel stability.

Abstract: An antiskid brake controller, which can secure a sufficient braking capability, avoid a locked state and maintain high reliability regardless of a road surface state without using a road sensor, includes a detector for detecting respective wheel speeds, a braking force adjustment unit which responds to the application of a brake and an electronic control unit (ECU) for calculating a control amount to the braking force adjustment unit to prevent the locking tendencies of respective wheels.

Abstract: A process for reducing yaw during braking in a vehicle having an anti-lock braking system (ABS) and traveling on a roadway having different coefficients of friction on opposite sides of the vehicle comprises regulating the braking pressures in the wheels of the vehicle during ABS-controlled braking so that a permissible braking pressure difference (.DELTA.P) between the braking pressures in the high and low wheels is maintained. The permissible braking pressure difference (.DELTA.P) is calculated by an electronic system based on an algorithm that takes into account the frictional value of the road, and/or the load on the vehicle, and/or the wheel base of the vehicle, and/or the wheel gauge of the vehicle, and/or the level of the center-of-gravity of the vehicle. The algorithm increases the value of the permissible braking pressure difference (.DELTA.P) as the frictional value of the road, the load of the vehicle, and the wheel base of the vehicle increase.

Abstract: A process for reducing yaw during braking in a vehicle having an anti-lock braking system (ABS) and traveling on a roadway having different coefficients of friction on opposite sides of the vehicle, is disclosed. The process comprises detecting the braking pressures in the wheels of the vehicle, calculating a permissible braking pressure difference, and adjusting the braking pressures in the wheel on the high friction side (high wheel) so as to maintain the permissible braking pressure difference. The permissible braking pressure difference is a variable value which depends mainly on the deregulating pressure (P.sub.max) at which the ABS begins to deregulate in the low wheel.

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: A circuit arrangement which is provided for a vehicle with an electronic anti-lock control system and is used to enhance the driving stability in critical driving situations includes circuits for the individual control of the braking pressure on the front wheels and for limiting the yawing torque following braking maneuvers on .mu.-split road surfaces. In defined, especially critical driving situations, in particular during driving maneuvers with an abrupt change in .mu.-conditions or during braking maneuvers on .mu.-patch road surfaces, when predetermined criteria for a critical driving situation of this type are satisfied, a special control is started to bring about braking pressure reduction on the HM-wheel for a predetermined period which is responsive to vehicle speed.

Abstract: A stability control device of a vehicle having a vehicle body, front and rear wheels, a device for estimating a liability of the vehicle body to drift out for producing a drift-out quantity which generally increases along with increase of the drift-out liability; a device for detecting lateral acceleration of the vehicle body; a brake for selectively applying a variable braking force to each of the wheels; and a controller for controlling the brake so as to variably apply a braking force to each of the wheels, wherein the controller controls the brake based upon the drift-out quantity such that a braking force applied to the rear wheels is increased with an increase of the drift-out quantity except for when the lateral acceleration is substantially minor.

Abstract: A method is provided that provides optimum anti-skid control when the vehicle is turning. If a vehicle enters a turning motion, the maximum frictional resistance corresponds to a larger slip ratio; therefore, in this method, the slip threshold is gradually increased to provide the optimum anti-skid control.

Abstract: The wheel speeds are measured by wheel speed sensors and are fed to an evaluation circuit. By way of the evaluation circuit, brake pressure control signals at least for increasing pressure and for decreasing pressure for a specific duration are then produced for the closed-loop/open-loop control of the wheel movement behavior. Moreover, brake pressure control signals are also usually output by the evaluation circuit in order to keep the brake pressure constant. These brake pressure control signals are fed to brake pressure control units for varying the brake pressure. The core of the invention consists in the fact that the duration at least of the first decrease in brake pressure at the front wheels is selected to be dependent on the speed of the vehicle at the start of braking.

Abstract: A method and system for modifying anti-lock brake control to a vehicle braking on a split mu surface. Each of the wheel speeds are sensed and compared to a wheel speed reference. If the speed of only one of the front wheels departs from the wheel speed reference in excess of a predetermined slip threshold, a split mu control is activated. Upon detecting a departure of the high mu wheel, a first pressure control profile is applied to the low mu wheel, while a second control pressure profile different from the first pressure control profile is applied to the high mu wheel. Once the vehicle has transitioned from braking on a split mu surface to braking on a homogeneous mu surface, normal ABS control pressure is applied to the wheels.

Abstract: An auxiliary brake system for a four-wheel-drive vehicle is disclosed whose main components of the present invention are four solenoid valves. These valves are located under the body of the vehicle, and are affixed in communication with the existing vehicle hydraulic brake system. Electrical wiring unites this system to two corresponding control buttons located within access to the driver. One control button functions to block the pressure for the left side of the vehicle; the other control button functions to block the pressure for the right side of the vehicle. The valves that control the front wheels of the vehicle may be mounted on the master cylinder, while the valves for the rear wheels may be in one body which would replace a `tee` fitting on the rear axle.

Abstract: When, after a yawing moment control starts in an anti-lock braking system the rear wheel on the low-.mu. road surface is locked and the speed of that wheel decreases below the threshold value VT1, the brake hydraulic pressure to the wheel on the low-.mu. road surface is decreased. At the same time, the brake hydraulic pressure to the rear wheel on the high-.mu. road surface is also decreased at reduced rate relative to the decrease on the low-.mu. wheel. As a result, a higher braking force acts on the wheel on the high-.mu. road surface than on the wheel on the low-.mu. road surface. When the speed of the wheel on the low-.mu. road surface decreases below the threshold value VT1 and when the speed of the wheel on the high-.mu. road surface decreases below the pressure-decrease restriction removal threshold value VT, the brake hydraulic pressure to the wheel on the high-.mu. road surface is decreased to be nearly equal to that to the wheel on the low-.mu. road surface to prevent the wheels on the high and .mu.

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: The present invention relates to an improved antiskid control apparatus for vehicles. When the front wheel on either one of the right and left sides is antiskid-controlled, this apparatus detects whether the road surface is in the condition of split .mu. in which the road surface friction coefficient is different between the right and left wheels by more than the prescribed value. When the road surface is found to have a split .mu. condition, antiskid control should be implemented on the front wheel mentioned above. To control the rise in brake fluid pressure, the other front wheel must then be shifted in whatever direction facilitates control of the threshold value. In other words, even if a wheel does not attain a sufficient coefficient of surface friction, antiskid control is needed to control easily the rise in brake fluid pressure. A large side force is applied continuously to the vehicle, thereby reducing slippage and cancelling the yaw moment.

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 method and system for detecting a braking event on a high mu surface while in four-wheel drive and modifying the anti-lock brake control accordingly. The method includes determining whether the vehicle is braking on a high mu surface and inhibiting brake pressure application to the rear wheels until it is determined the vehicle is braking on a high mu surface. The system includes wheel speed sensors, an electronic control unit and control valves for carrying out the method.

Abstract: An anti-skid brake system includes at least one wheel speed detecting device for detecting a rotational speed of each of a plurality of wheels separately; a ground friction coefficient estimating device for estimating a ground friction coefficient .mu. based on a rate of change of signals relating to the wheel speeds detected by the at least one wheel speed detecting device; a braking force adjusting device for adjusting a braking force applied to each wheel; an anti-skid control device for controlling the braking force adjusting device to prevent the wheels from being locked in accordance with the ground friction coefficient .mu. estimated by the ground friction coefficient estimating device; a locked wheel detecting device for detecting a number of locked wheels at least based on the wheel speeds detected by the at least one wheel speed detecting device; and an estimation process altering device for altering an estimation process for estimating the ground friction coefficient .mu.