Abstract: The invention concerns a vehicle stabilizing device for setting or modifying brake pressures in the wheel brakes of a braking system with diagonally divided braking circuits.

Abstract: A method for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes the following steps: identifying a driving situation on a roadway with sidewise different coefficients of friction and, when the driving situation is identified and traction slip is encountered on both wheels, decreasing the brake pressure of the driven wheel on the low coefficient-of-friction side. A device for controlling the traction slip of a vehicle on a roadway with sidewise different coefficients of friction includes a determining device for determining a driving situation on a roadway with sidewise different coefficients of friction, and a brake actuation control which decreases the brake pressure of the driven wheel on the low coefficient-of-friction side when the driving situation is identified and traction slip is encountered on both wheels.

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: Vehicle motion control devices and methods systematically treat a conditions of each wheel to acquire and maintain the vehicle behavior stability together with anti wheel lock and wheel spin processing, braking forces distribution. Device for controlling a running behavior of a vehicle comprises means for estimating a road reaction force on each wheel, means for calculating a yaw moment around a centroid of the vehicle body generated by the road reaction force on each wheel, and means for controlling driving and braking forces on each wheel based upon the yaw moments so as to stabilize a running of the vehicle. Spin and Drift conditions are detected through presently generated yaw moments and critical yaw moments which can be generated by a road reaction force assumed to be maximized. Physical parameters of each wheels, required for detecting and controlling the behavior of the vehicle are estimated with a theoretical tire model.

Abstract: In a vehicle attitude control apparatus, a steering actuator is controlled so that a steering angle matches a target steering angle. In an understeer condition; the braking force on the inside wheels is increased and drive power applied to the outside wheels is larger than applied to inside wheels. In an oversteer condition, the braking force on the outside wheels is increased and drive power applied to the inside wheels is larger than applied to outside wheels. The steering actuator is controlled so that a behavior index value corresponding to the change in the vehicle'behavior, that occurs based on the change in the steering angle, matches a target behavior index value that reflects the amount of operation of an operation member. A vehicle yaw moment and an amount of control of the steering actuator vary due to steer conditions, wheel lateral slip angle and brake force control.

Abstract: In a steering device for a vehicle, the movement of a steering actuator driven by operation of an operating member is transmitted to vehicle wheels, in such a manner that the steering angle changes, without the operating member being coupled mechanically to the vehicle wheels. A first target yaw rate is calculated in accordance with the detected vehicle speed and a first steering angle set value, which corresponds to the detected amount of operation and vehicle speed. A second target yaw rate corresponding to the detected lateral acceleration and vehicle speed is calculated. A second steering angle set value, which corresponds to the difference between the detected yaw rate and a target yaw rate, as which the first target yaw rate or the second target yaw rate whichever has the smaller absolute value is taken, is calculated.

Abstract: A method and a device for adjusting a braking action at wheels of a motor vehicle are described. In response to a detected &mgr;-split situation, a reduction of the braking action at a low wheel of a rear axle is brought about as a function of a reduction of the braking action at a same-side wheel of a front axle. One variant of the method and device no braking action is applied to the low wheel of the rear axle. As a result of the two variants, the low wheel of the rear axle, which is at a side that has a lower coefficient of friction and does not significantly contribute to the overall braking action, is rendered virtually without brake pressure and can therefore function as a reference variable, i.e., vehicle reference velocity. As a result, especially in light commercial vehicles, the braking distances are shorter in response to braking actions in a &mgr;-split while maintaining stable driving performance during the entire braking action.

Abstract: A method of controlling travel behavior of a vehicle provides assistance to the driver of the vehicle before the occurrence of travel conditions which are difficult to control. A vehicle taking a curve tends not to follow the travel curve indicated by steering, often resulting in understeering as the travel speed increases. At very high speeds in a curve, such behavior can lead to conditions that are difficult for the driver to control. Rather than intervening when an unstable travel state is already present and control of the vehicle rendered difficult, as practiced in conventional systems and processes for the regulation of travel dynamics, the wheel brake of a rear wheel of the vehicle on the inside of the curve is already subjected to a weak braking force when a relatively minor tendency to understeer occurs, so that the understeering tendency is reduced or eliminated.

Abstract: In an anti-lock brake system mounted on a vehicle wherein when the vehicle is braked in an emergency during running, an increase in the road surface friction force or road surface friction coefficient owing to an increase in the brake pressure is detected by a road surface friction force detecting device or road surface friction coefficient detecting device. The optimum control start point associated with an increase in the signal value of the road surface friction force F or road surface friction coefficient &mgr; provided by the road surface friction force detecting device or road surface friction coefficient detecting device is decided by using a decrease in the wheel speed, i.e., by using the wheel speed &ohgr; or d&ohgr;/dt. Thereafter, from the point where the specified value of control based on F or &mgr;, or dF/dt or d&mgr;/dt, the brake pressure is moved from the pressure increasing mode to the pressure retaining or decreasing mode.

Abstract: A vehicle running condition judgment device for accurately detecting a change in a road surface condition and a vehicle's limit running condition. With substitution of respective tire characteristics and a detected state quantity into a vehicle motion model, vehicle slip angles are estimated for respective assumed road surface conditions. Based on the current state quantity and the last estimated vehicle slip angle, currently estimated vehicle slip angles for the respective assumed road surface conditions are compensated. A differential operation section calculates an estimation value of a vehicle slip angular velocity for each of the assumed road surface conditions based on the compensated vehicle slip angles for the respective assumed road surface conditions. Meanwhile, an operation section calculates a detection value of a vehicle slip angular velocity based on the detected state quantity.

Abstract: Wheelslip is controlled in an automotive vehicle having at least one wheel for which control is desired. Each wheel is controlled by a corresponding element of a command wheelslip vector. The method includes determining a minimizing wheelslip vector minimizing the time rate of change of weighted vehicle kinetic energy and a resulting minimum time rate of change of weighted vehicle kinetic energy. A maximizing wheelslip vector maximizing the time rate of change of weighted vehicle kinetic energy and a resulting maximum time rate of change of weighted vehicle kinetic energy are also found. The command wheelslip vector is determined from an interpolation of the minimizing wheelslip vector and the maximizing wheelslip vector. The interpolation is based on a desired time rate of change of weighted vehicle kinetic energy.

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 an anti-lock brake system mounted on a vehicle wherein when the vehicle is braked in an emergency during running, an increase in the road surface friction force or road surface friction coefficient owing to an increase in the brake pressure is detected by a road surface friction force detecting device or road surface friction coefficient detecting device. The optimum control start point associated with an increase in the signal value of the road surface friction force F or road surface friction coefficient &mgr; provided by the road surface friction force detecting device or road surface friction coefficient detecting device is decided by using a decrease in the wheel speed, i.e., by using the wheel speed &ohgr; or d&ohgr;/dt. Thereafter, from the point where the specified value of control based on F or &mgr;, or dF/dt or d&mgr;/dt, the brake pressure is moved from the pressure increasing mode to the pressure retaining or decreasing mode.

Abstract: An automotive vehicle stability control system determined which is a main cause of a change in a change rate of a yaw rate difference of an actual yaw rate from a target yaw rate between a change in the actual yaw rate and a change in the target yaw rate when the change rate of the yaw rate difference exceeds a specified change rate, increase threshold slip angle for starting braking control based on slip angle following the driver's intention when the main cause is the change in the actual yaw rate and increases an upper limit of target slip angle so as to allow the target slip angle to be increased according to a driver's steering operation when the slip angle preferential braking control takes place.

Abstract: A vehicle turn control system has a controller connected to a steer angle detecting section, a vehicle speed sensor and a vehicle turn state detecting section. The controller calculates a target vehicle turn state from a steer angle and a vehicle speed and controls brake pressure supplied to a brake cylinder of each wheel of the vehicle according to a difference between the actual vehicle turn state and the target vehicle turn state. The controller executes a pre-charge control of a brake cylinder of a wheel to be braked next and restricts the pre-charge control according to the vehicle turn condition.

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: A vehicle behavior control apparatus is provided which is designed to estimate the state of behavior of a vehicle body and to apply the brakes to wheels for suppressing an unwanted change in behavior of the vehicle body. The apparatus determines a lateral momentum of the vehicle body during traveling to estimate the state of behavior of the vehicle body based on the speeds of the wheels and calculates a target braking effort to be produced by each of the brake actuators based on the state of behavior of the vehicle.

Abstract: An antiskid brake controller utilizes measured wheel speed in order to provide brake control for a vehicle such as an aircraft. The controller estimates the speed of the vehicle via approximation based on the measured wheel speed and a model of the mu-slip ratio curve representing the wheel to running surface friction characteristics. The controller then predicts the slip ratio based on the measured wheel speed and estimated vehicle speed. The difference between the predicted slip ratio and a predefined desired slip ratio is used to drive a modified integral controller segment to achieve maximum obtainable friction. In another embodiment, the controller measures and integrates the applied braking torque in order to estimate the vehicle speed. The estimated vehicle speed is again combined with the measured wheel speed to determine an estimated slip ratio. The controller compares the estimated slip ratio with a predefined desired slip ratio which again drives a modified integral controller.

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: A braking force control system and method of a vehicle comprises a steering angle detecting section for detecting a steering angle, a vehicle speed detecting section for detecting a vehicle speed, an actual yaw rate detecting section for detecting an actual yaw rate, a target yaw rate calculating section for calculating a target yaw rate, a target yaw rate restricting section for restricting the target yaw rate to an upper limit value, a yaw rate deviation calculating section for calculating a yaw rate deviation of the actual yaw rate and the target yaw rate, a target braking force calculating section for calculating a target braking force, a braking wheel determining section for determining a braking wheel, an output judging section for judging whether the yaw rate deviation is in a control zone or in a noncontrol zone.

Abstract: A brake system control for use in a vehicle with wheels, wheel brakes and a body, comprising the steps of: measuring a plurality of vehicle parameters; responsive to the measured parameters, determining at least a vehicle yaw rate, a vehicle slip angle, a desired yaw rate and a desired slip angle; responsive to the measured parameters, estimating a coefficient of adhesion between the vehicle wheels and a road surface; implementing a control responsive to the vehicle yaw rate and the desired yaw rate with a first authority and responsive to the vehicle slip angle and the desired slip angle with a second authority, wherein the first authority increases as the estimated coefficient of adhesion increases and decreases as the estimated coefficient of adhesion decreases; and controlling the wheel brakes responsive to the control to reduce a first difference between the vehicle yaw rate and the desired yaw rate and to reduce a second difference between the vehicle slip angle and the desired slip angle.

Abstract: A process for reducing the yawing moment that develops during hard braking in a vehicle equipped with 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 driver must compensate for the yawing moment by steering towards the side that has the lower coefficient of friction. The process comprises venting the brake cylinder of the front wheel on the side with the higher coefficient of friction for a time t.sub.AH that is calculated in an electronic control module. The algorithm for computing t.sub.AH depends on the venting time t.sub.AL at the front wheel on the side with the lower coefficient of friction and the maximum or so-called deregulating pressures attained in the cylinders of the rear wheels. The electronic control module receives pressure information from pressure sensors and ascertains the venting time t.sub.AL that the ABS produces at the slipping front wheel.

Abstract: Circuitry for a brake system with traction slip control by brake management, wherein the traction slip control thresholds are variable, in excess of which braking pressure is introduced into the wheel brake of the overspeeding wheel. After the overspeeding of a wheel of a driven axle and the commencement of the control, the traction slip of the second, non-controlled wheel of the driven axle is determined and evaluated to produce a correction factor which adapts the traction slip control thresholds of the controlled wheel to the instantaneous slip of the second, non-controlled wheel.

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: An apparatus for controlling an attitude of a motor vehicle, including a longitudinal force control device for controlling a torque of a wheel of the motor vehicle to thereby control a longitudinal force which acts in a longitudinal direction of the vehicle between the wheel and a road surface, and a tire slip angle control portion for controlling a tire slip angle of the wheel such that an absolute value of the tire slip angle is smaller when the longitudinal force control device is in operation than when the longitudinal force control device is not in operation.

Abstract: A control process for the driving stability control of a motor vehicle is provided. The signal sent out by a control law unit to generate the necessary additional torque is sent to a distribution logic unit, which subsequently sends the pressure signals used to actuate the individual wheel brakes. The superimposition of these pressure signals and the pressure signal characterizing the driver's desire to brake (as well as the subsequent superimposition of these adjusting signals to adjusting signals arriving from other brake pressure controllers, such as ABS, TSC, EBV) leads to interfaces in which differing physical variables must be compared or superimposed. The necessary conversion of these variables is expensive and increases the inaccuracy of the control system. Simplified interfaces are provided, to achieve improved processing of the brake pressure desired by the driver, and possibly to avoid the conversion of the individual signal variables.

Abstract: A braking force control system and method of a vehicle comprises an estimated yaw rate calculating section for calculating an estimated yaw rate on a road surface having low friction coefficient, a target yaw rate differential calculating section for calculating a target yaw rate differential, an estimated yaw rate differential calculating section for calculating an estimated yaw rate differential, a yaw rate differential deviation calculating section for calculating a deviation of the both differentials, a first target braking force calculating section for calculating a first target braking force, a yaw rate deviation calculating section for calculating a deviation of an actual yaw rate and a target yaw rate, a second target braking force calculating section for calculating a second target braking force, a final target braking force calculating section for calculating a final target braking force based on the first and second target braking forces.

Abstract: A method for preventing the driven wheels of an automotive vehicle from spinning provides that whenever one of two driven wheels of one axle of the vehicle has a lower friction coefficient with the road surface than the other wheel of said axle and the one wheel shows a spinning tendency, brake pressure is built up at said wheel, with the rotational speed of the other wheel being measured, and whenever the rotational speed exceeds a specified value with respect to a vehicle reference speed, the brake pressure at the one wheel is reduced or maintained constant.

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: A dynamic behavior estimate system of an automotive vehicle includes a parameter reading unit which reads an input signal indicative of one of vehicle behavior parameters when the vehicle operates in a curved path. A discriminating unit outputs a detection signal indicative of discrimination of an instability of the vehicle when an inference value from the above one of the vehicle behavior parameters exceeds a reference value. A slip angle detecting unit detects a maximum slip angle that can hold a lateral force of front or rear wheels of the vehicle below a critical value, and sets the reference value equal to the maximum slip angle. An inference value setting unit determines an inference value from the above one of the vehicle behavior parameters, and sets the value, used by the discriminating unit, equal to the inference value, thereby allowing the discriminating unit to detect whether the inference value exceeds the reference value.

Abstract: A slip control system determines friction/slip characteristics of tires of a road vehicle equipped both with an antilock system to permit an individual brake pressure control on individual vehicle wheels. The front wheel brakes are connected to a primary output pressure space of the tandem master cylinder, and the rear wheel brakes are connected to a secondary output pressure space of the tandem master cylinder. A first bore stage of a housing of the tandem master cylinder forms a housing-defined boundary of the secondary output pressure space. An inner piston flange movably seals off a pressureless downstream chamber in relation to an inner portion of the first bore stage. An intermediate wall of the housing delimits the bore stage relative to a central bore stage which extends from a third bore stage receiving a primary piston.

Abstract: A vehicle yaw control for a vehicle having wheel brakes wherein the wheel brakes complement driver controlled steering efforts by establishing a maximum steering angle that can be used for any given coefficient of friction at the wheel-road interface and for any given speed, thereby achieving optimum lateral control during turning maneuvers by compensating for under-steering and over-steering for each driving condition.

Abstract: To prevent a great variation of a detected wheel velocity for a period of time after a front wheel sensor or a rear wheel sensor for detection of a wheel velocity actually fails until a microcomputer detects the failure, it is determined whether or not an output pulse period of a front wheel sensor is equal to or shorter than a predetermined period. When the output pulse period exceeds the predetermined period, it is determined that there is the possibility that the front wheel sensor may be in failure, thus a front wheel velocity for a predetermined number of control cycles before (a front wheel velocity before the failure) is adopted as a front wheel velocity of the present control cycle. Also, a rear wheel velocity is calculated in a similar manner. For a time after a failure actually occurs until the failure is detected by a microcomputer, driving force control is not started even if other starting conditions for driving force control are satisfied.

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: 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.