DE102004008265A1 - Control method for a motor vehicle's wheel drift control system uses a wheel drift/slippage controller to generate adjustment variables for individual wheels - Google Patents

Abstract

A wheel drift/slippage controller generates adjustment variables (Sy1) for individual wheels. An actuator (AktB) can alter wheel drift with an adjustment variable for an individual wheel. A correcting variable (Ly1) that represents wheel contact force (FL) on a corresponding wheel alters an individual wheel's adjustment variable to a new adjustment variable (Syk1) for the actuator.

Description

The The invention relates to a method for slip control on wheels of a Motor vehicle according to the preamble of claim 1

It is well known that modern motor vehicles with so-called Antilock braking systems are equipped to prevent the locking of the vehicle wheels can prevent a braking operation. If, however, during acceleration operations, an unintentional spin avoided the vehicle wheels is to be recommended, the use of a known per se Traction control system. In addition, through the use a driving stability program (ESP, for example) is an undesirable one Turning the vehicle around its vertical axis can be prevented.

Despite the use of these known programs and / or systems in a motor vehicle, there is a need to further improve the performance of modern motor vehicles. For example, from the DE 199 04 216 A1 a method and apparatus for dynamically detecting changes in the vehicle's center of gravity. In this method, during cornering of the vehicle at least two vehicle wheels a first state variable is detected, which corresponds to the respective wheel load or Radaufstandskraft. The detected state variables are then compared with reference values representing the respective cornering. From the deviation between the two mentioned values, a change in the center of gravity of the vehicle is calculated. If the change in focus indicates a critical tilting condition, anti-tilt countermeasures are then initiated. As state variables corresponding to the wheel contact force, the spring travel measurable at the wheel suspension, the spring pressure, the damper pressure measurable at the shock absorber, the tire inner pressure or the side deformation of the vehicle tire are mentioned.

In addition, from the DE 100 17 506 C2 It is known that today's driving stability programs monitor the rotation of the motor vehicle wheels by means of sensors and derive therefrom the control variables required for a control process. These control variables are, for example, the braking forces for the individual vehicle wheels. In addition, according to this document, the known driving stability programs could be improved if information about the wheel contact forces of the individual vehicle wheels were utilized. So it makes sense to apply a wheel with a lower Radaufstandskraft with less braking force than a wheel with a high wheel load in a braking operation, so that in the same driving situation, a blocking of the wheel can be suppressed.

In addition, in the DE 100 17 506 C2 proposed that the wheel contact force can be calculated by separate determination and subsequent addition of the static and the dynamic part of the Radaufstandskraft. Static wheel contact force is understood to be the wheel contact force which is generated on a vehicle wheel solely on the basis of the vehicle mass acting in the vertical direction. By contrast, dynamic wheel contact force refers to that force which is generated on a vehicle wheel due to a vehicle body swinging in the vertical direction or such a vibration of the vehicle wheels.

In The prior art does not show how the determined wheel-up force with an existing anti-lock braking system, a traction control system or a driving stability program link meaningfully leaves.

In front In this background, the invention is based on the object Introduce method with the operating behavior of a motor vehicle with an anti-lock braking system, a traction control system or a driving stability system to the effect that variable Radaufstandskräfte, the for example, by road bumps, by movements of the vehicle body due to driving dynamics situations or due to vehicle load change arise, for controlling and regulating the operation of the vehicle service brake can be used.

The solution This object is apparent from the features of the main claim, while advantageous developments and refinements of the invention the dependent claims are removable.

Of the Invention is based on the finding that modern motor vehicles usually at least with an anti-lock braking system, a traction control system or a driving stability system are equipped. These systems have in common that at all a so-called slip control is used whose job it is the operation the service brakes on the vehicle wheels optimal driving situation to regulate.

In addition, larger and higher-value vehicles (high-class vehicles) today also usually have a level control system, with the help of the distance of the driving body is manually or automatically adjustable from the track or from the wheel axles. For this purpose, air springs are usually used whose axial length is controlled on the basis of sensor information indicating the said distance at or in the region of at least one vehicle wheel.

The Invention makes this trend to vehicle equipment advantageous be used by the distances determined at the distance sensors also for Determination of the wheel contact force can be used. Of course you can too other sensors are used for this purpose, with their help changing over time wheel contact can be determined. In addition, the preferably determined wheel individually Radaufstandskraft to improve the control and regulation activity used in the aforementioned programs or systems.

To the better understanding The invention should be noted here that for determining the respective Radaufstandskraft course not such distance changes for example between a body component and the wheel axle considered Be alone on a manual or automatic level adjustment are attributed. Much more becomes a practical control and regulation program only Distance changes for the in Talk about controlling the service brake on the effect of static and / or dynamic forces on the Suspension or on the vehicle body are due.

Accordingly, the invention is based on a method for motor vehicles with a wheel slip control system, which comprises at least:
Means for detecting wheel slip on one or more vehicle wheels, a wheel slip controller that generates one or more wheel-specific manipulated variables Sy1, and one or more actuators AktB or AktC, with which the wheel slip can be changed by means of the wheel-individual manipulated variable Sy1.

to solution the task and thus to improve the above Slip control system is now also provided that at least one wheel-specific manipulated variable Sy1 of the Radschlupfreglers by the wheel contact force FL at the corresponding Wheel representing Correction value Ly1 too a new manipulated variable Syk1 or Syk2 for the actuators AktB or AktC is changed.

In Development of this invention is provided according to the method that the manipulated variables Syk1 or Syk2 for the actuator AktB or AktC with the determined braking or acceleration default X3, X31 of the driver linked (added or subtracted), resulting in an effective manipulated variable Y1, Y11 for the brake actuator AktB and / or the acceleration actuator AktC results. The manipulated variable Y11 for the acceleration actuator AktC is for security reasons as a rule, the acceleration default by the Driver have equal or reducing value.

to Determining the correction quantity Ly1 at least one of the wheels is the distance H of the vehicle body from the wheel axle or the distance between the vehicle floor and the road is detected and used.

On the other hand considered the other correction variable Ly2 the Influence of future occurring changes the vehicle height and the wheel contact force FL. To determine the correction quantity Ly2 is For example, detects the steering angle X1 of the vehicle steering and used.

In In this context, it is considered advantageous if the correction quantity Ly1, Ly2 an increase the value of the manipulated variable Syk1, Syk2 for the actuators AktB, AktC then causes or allows, if the future too expected wheel-lift force FL will increase, respectively a reduction of the manipulated variable Syk1, Syk2 leads, if the future expected wheel contact force FL will be lower. It will provided that by a higher Manipulated variable on the brake actuator AktB a higher Braking torque generated and the acceleration actuator a higher drive torque is effected.

moreover can be provided that the target slip Ss at one or more wheels dependent on of wheel contact forces FL determined on at least one wheel changed with the wheel-specific target slip Ss1, Ssr for each the vehicle wheels be different in size can.

The Invention also relates to a variant of the method according to the one or more wheel support force FL representing Sizes Ly1, Ly2 wheel-specific brake and / or traction forces determined and used for actuator control. These traction forces can Describe adhesion between the road and the tires of the vehicle wheels.

In addition, it can be provided that, from an axle-by-block comparison of the determined wheel-specific braking and / or traction forces, that wheel is selected at which the lowest braking and / or traction force occurs, and the wheel-specific setpoint slip Ss1, Ssr at the other wheel at the same Vehicle axle is lowered to the effect that the braking and / or traction force occurring there is the same size as in the aforementioned Wheel is.

In Another variant may be provided that from the axles Comparison of the determined wheel-specific braking and / or traction forces that Wheel is selected, at which the least braking and / or traction force occurs that the target slip Ss1, Ssr on the other wheel at the same Vehicle axle is lowered so that the occurring there Braking and / or traction force equal to the size of the former Rad is, and that over a delay element the target slip Ss on the wheel at which the target slip Ss1, Ssr lowered was, the braking and / or traction force back on those Value increased is, this had before the Sollschlupfabsenkung.

Around the driving stability not to endanger such a vehicle operated the aforementioned variants of the method are preferably used only when the yaw rate of the vehicle is a predetermined threshold does not exceed.

at an exceeding of such a yaw rate threshold, the wheel-specific braking and / or traction forces on at least one of the wheels preferably evaluated, as a result of this evaluation the manipulated variable Syk1 for the brake actuator AktB increased at that wheel becomes, by a torque opposite to the yaw on the vehicle exercised and that is the manipulated variable Syk1 is reduced at that wheel on which a yaw supporting Torque is applied to the vehicle.

Regarding the determination of the Istschlupfwertes Si of the vehicle wheels is preferably provided that this wheel individually by subtraction between the measured wheel speed and one of the measured Radantriebsdrehzahlen calculated vehicle speed determined becomes.

Finally is It is part of the invention that the presented method and its variants as a separate control and regulatory procedure operated in a control and regulating device of a motor vehicle or that this part of a control program an anti-lock braking system, a traction control system and / or a driving stability control system in a motor vehicle.

To the better understanding The invention is the description of a drawing attached. In this is represented in a control flowchart, in which way the information about the wheel loads recorded in a control and regulation program for anti-skid control, driving stability control and / or traction control Find input and there to control variables for a brake actuator or an acceleration actuator are processed. It shows

1 a program flow structure for the method according to the invention,

2 a first variant too 1 , and

3 a detailed representation of the calculation module 14 according to 1 and 2 for wheel-specific nominal slip determination.

Be known generic control and control methods stored as programs in control and regulating devices and operated there as well. These devices are equipped with sensors and actuators signal-wise connected, so that sensor information is recorded and processed as well as control commands for the actuators generated and can be forwarded.

The in 1 and 2 illustrated variants of control structures operating according to the invention is a jointly acting on each vehicle control and control sequence, which is described by way of example for a single wheel in the following. Of course, this method can also be extended to several vehicle wheels.

at The said control and regulation process is first by a speed sensor Srad on a vehicle wheel whose wheel speed Nrad detected and fed to a calculation module F8. This calculation module F8 calculates an actual slip value Si which corresponds to a given value and stored in an electronic memory or setpoint generator F1 Target slip value Ss in a subtraction K is compared.

The differential slip value Ds formed in the subtraction element K is then fed to a slip controller F7 which generates an output signal Sy1 and which directly or after passing through a filter and / or regulation module F6 according to FIG 1 as an effective drive signal Y1 to a brake actuator AktB of the vehicle wheel considered here, or according to 2 is passed as an effective drive signal Y11 to an acceleration actuator AktC. The filter and / or control module F6 is effective, for example, as a subtraction element, while the slip controller F7 is preferably designed as a P or PI controller.

After actuation of the actuator AktB, AktC, a new wheel speed Nrad sets, which is then detected by the speed sensor Srad and in as described above in a new regulatory cycle.

According to the invention is the wheel load or wheel contact force FL as an additional size in the described control loop, so that the operating behavior of the motor vehicle with respect to an anti-lock control function, a Traction control function and / or a driving stability function changed favorably.

For this purpose, the distance H of the body to the wheel axle or the spring deflection of at least one vehicle wheel on the vehicle suspension is first determined, for example, and the calculation of the wheel contact force FL acting on the vehicle wheel considered here is carried out in a calculation module F3. The Radaufstandskraft FL is in a first approximation substantially proportional to the said distance H or to the compression travel. For the calculation of the wheel contact force FL, for example, the equation FL = K1 * H + K2 used in the K1 indicates the rigidity of a vehicle air spring in its rest position, K2 indicates a wheel load or wheel contact force in the rest position of the vehicle.

Subsequently, will from the wheel contact force FL in a calculation module F4 a correction value Ly1 calculated and with the manipulated variable Sy1 in a link A merged. The output value of this logic element A is then the Radlastbezogen corrected control value Syk1 or Syk2, which subsequently after passing through the filter and / or control module F6 as manipulated variable Y1 or Y11 is passed to the actuator AktB, AktC.

By the procedure of the invention is it possible dynamic wheel load fluctuations in the regulation of braking power or in the drive torque control for one or more wheels of a Motor vehicle to include. This is different Method distinct and advantageous from the known prior art, in which the wheel load in this regard no control technology consideration has found. Thereby can for example, by rolling movements of the vehicle body or Dynamic wheel loads generated by a poor road condition or wheel contact advantageous in the control of an anti-lock braking system, a traction control system or a driving stability system become.

So is preferably in an anti-lock braking system always the braking force at the vehicle wheels elevated, if through an increased Radaufstandskraft also a higher Transfer braking torque to the roadway can be without the risk of blocking the vehicle wheels. On that way Be very advantageous shorten the braking distance of a vehicle on.

at Use of this function in a traction control program the traction control can be done better than before, since the slip control with higher Security performed and a better acceleration behavior especially in such operating situations can be generated in which variations in vehicle body or bad road conditions to be recorded. If, for example, a rolling motion of the vehicle body can cause a short-term relief of a vehicle wheel driving stability locking the braking force on this vehicle wheel are withdrawn.

The invention therefore comprises a method for influencing a slip control on one or more motor vehicle wheels, in accordance with 1 and 2 detects the speed Srad at least one wheel and is calculated in the calculation module F8 of the relevant control and regulating device of the actual slip value Si. Subsequently, the differential slip value Ds is calculated by forming the difference between the actual slip value Si and the predetermined target slip value Ss, with the aid of which a control variable Sy1 is determined in the slip controller F7.

Of the Target slip Ss is not to be understood here as a size to which the Istschlupf Si permanent as usual Is regulated, but defines a limit of the slip that did not pass may be. This is important because when the nominal slip value is exceeded If there is a risk of wheel lock or wheel spin, which could make the control loop unstable.

In addition, in order to improve the aforementioned slip control system, it is provided that said manipulated variable Sy1 is changed to a corrected manipulated variable Syk1, Syk2 by an application of the correction value Ly1, which represents the load-dependent component of the wheel contact force FL of at least one vehicle wheel ( 1 ). This manipulated variable Syk1 or Syk2 is then then used to control the brake actuator AktB or the acceleration actuator AktC, wherein the supply of this manipulated variable Syk1 or Syk2 can be done via the aforementioned filter and / or control module F6.

This procedure is described below with the help of 1 for carrying out a Bremsmanö vers deepened clarified. In such a braking operation, the filter and / or control module F6 represents a subtraction point, which may be executed both mechanically or electronically. Its function is to reduce the brake pressure X3 predetermined by the driver of the vehicle by the brake pedal position X2 by the control value Syk1 calculated by the slip controller F7 and adjusted in the link A to the wheel contact force FL. The result is then the manipulated variable Y1, which is fed to the brake actuator AktB. An increase in the value of the manipulated variable Y1 causes a higher braking force, while a reduction of Y1 has a reduction.

Of the Driver-specified brake pressure X3 may be present on some anti-lock braking systems for example, from the brake pedal position X2 about using a Potentiometer detected, processed in a calculation module "brake pressure" F5 and be fed to the filter and / or control module F6.

In In practice, the slip controller F7 is preferably constructed so that the manipulated variable Sy1 not activated slip control F7 has the value zero, so that in the filter and / or control module F6 in such a case no lowering the manipulated variable Y1 for the brake actuator AktB takes place. Exceeds, however the actual slip Si the predetermined target slip Ss, then the slip control F7 active and specifies a manipulated variable Sy1 for example, a positive value. This means for the filter and / or control module F6 that the brake pressure specified by the driver X3 is lowered by the corresponding value.

Farther are preferably so-called hysteresis by the target slip value Ss in which the slip control F7 slips during a full braking continuously regulates. As this is for the Invention is not of further importance, will not be discussed further.

The operation of the method according to the invention during an acceleration process of the vehicle is in 2 shown. The structure of the measured value acquisition and control process largely corresponds to that in 1 however, the illustrated frames may have other transfer functions.

One Such acceleration process is by the driver by means of a Accelerator pedal deflection signaled at the deflection angle X21 of Accelerator is recognizable. This deflection angle X21 is using an accelerator pedal sensor detected by a calculation module F51 in a drive torque request X31 of the driver converted and the filter and / or control module F6 forwarded. The calculation module F51 may, for example, be a nonlinear Follow the characteristic curve.

in the Filter and / or control module F6 is then signaled by the driver Drive desired torque X31 reduced by the correction value Syk2, the from the output value Sy1 of the slip controller F7 and the correction value Ly1, Ly2 was generated in the manner already described. The result determined effective manipulated variable Y11 describes after all that indeed requested drive torque, which is the current load-dependent proportion the wheel reaction FL considered.

This corrected drive torque is then in the form of the manipulated variable Y11 an "intelligent Actuator "AktC, such as a throttle actuator on the vehicle engine or but a motor control device forwarded, which the torque generation of the drive motor controls and / or regulates.

exceeds the measured wheel slip, so the actual slip Si, due to a To strong wheel torque the target slip value Ss, so is the Slip controller F7 active and reduces over a larger manipulated variable Syk2 the driver's resulting desired drive torque X31. Due to the reduced drive torque is ultimately the wheel slip reduced, which closes the loop. Again, will be beneficial the wheel contact force FL determined on this wheel is used according to the invention, to the manipulated variable Sy1 accordingly change, that with greater wheel contact FL the manipulated variable Lyk2 reduced and thus a greater traction is produced.

Of the Advantage of the mentioned method is that when uneven Lanes on which the Radaufstandskraft constantly changing, the Slip control of a vehicle wheel is improved to that effect, that now at a Aufstandskraftentlastung a wheel at the same time the braking torque of the wheel or the drive torque of the vehicle engine can be reduced without first increasing the slip or even an interruption of the brake or traction specific road contact occurs. Such a relief of the vehicle wheel, for example an enforced by driving through a lane puncture To be a boast.

In an embodiment of the invention, a statement about the wheel load or wheel contact force is obtained from variables that indicate the distance H of the vehicle body from the roadway or from the wheel axle to the vehicle body. An advantage of such a procedure is that the necessary distance sensors in some vehicle types, for example, for a headlight range regulation device or for a level control device already exist. With the help of these sensors, therefore, both slow and load-dependent changes in load on the vehicle wheels as well as changes generated by driving dynamics can be detected and used for determining the wheel contact force.

Another development of the invention relates to the dynamic change of the setpoint slip Ss as a function of the determined wheel contact forces. This will be described below in another example of a braking process in synopsis of 1 and 3 explained. However, the basic idea used is also applicable to an acceleration process of the vehicle. The procedure and the necessary calculation modules are described in detail in 3 as well as a program complex or calculation module 14 in 1 respectively. 2 shown.

Based on the wheel-individually determined right and left wheel contact force FL1L, FL1R and the current wheel-specific wheel slip Sir or Sil, a wheel-individual, right-hand or left-hand wheel braking force Frl or Frr in the vehicle longitudinal direction x is determined. For this purpose, the road friction coefficient μx is first determined, for example, by means of estimation methods known in the literature and stored in the control and regulating device in the calculation modules F9 and F10. In this case, the road friction coefficient μx is calculated in a simplified manner from the wheel-specific wheel braking torque MBr or MB1 currently in effect and the current actual slip Sir or Sil calculated. Simplified, the braking force Frl for the left front wheel and the braking force Frr for the right front wheel can be determined by the equations Frl = μxl * FL1L and Frr = μxr · FL1R, where μxl and μxr are the aforementioned road friction values in the longitudinal direction x on the left and right front wheels.

Based the determined wheel-individual braking force Frl, Frr can then for example when braking during a straight-ahead drive the braking forces be wheel individually controlled and regulated so that the vehicle body no or only a small torque is generated. To the wheel braking forces Frl, Frr compared in a comparison module F11 and then the lower wheel braking torque of the two wheels selected. At the wheel where the greater braking force acts, then the wheel-individual braking force Frlsoll, Frrsoll in the calculation modules F12, F13 to corrected target slip values Ssl, ssr changed so far, until the wheel braking forces on both wheels are the same size. These wheel-individual and constantly updated nominal slip values Ssl, Ssr are preferably stored in the electronic memory F1 stored and are as described Regulation procedure available.

In In a further embodiment of the invention, the method becomes advantageous applied only when no yaw forces are exerted on the vehicle, So almost straight ahead. About this state variable can be distinguished, whether the vehicle high torques around its Vertical axis is exposed, so that accordingly different activities can be taken. For example, if the vehicle is not yawing, it will be the same axle-by-axle Radverzögerungskräfte when Brakes or drive forces generated during acceleration.

In another development of the invention, which also in the 1 and 2 1, one or more quantities are calculated relating to the future variation of the wheel contact force FL on one or more vehicle wheels. The advantage of this process variant is the fact that even before the actual Radaufstandskraftveränderung occurs, the wheel slip is such predictive changeable that, for example, in the sudden steering angle impact optimally adjusted deceleration force can act on the wheels. For this purpose, steering angle X1, for example of a vehicle steering wheel, is preferably detected by means of a steering angle sensor, processed in a filter and calculation module F2 and forwarded to the logic element A as forward-looking correction values Ly2.

With Help of the mentioned measured values can be the effect of the steering or deflection movement on the change the wheelwright forces estimated in advance become. So be at a sudden steering wheel to the left the wheel riot of the right wheels increased shortly thereafter be while the left vehicle wheels decline. By the consideration this information and shortcuts in the link A can anticipate the wheel braking or acceleration torque become.

A

combiner

AktB

actuator service brake

AKTC

Beschleunigungsaktuator

ds

differential slip

F1

Setpoint generator

F2

filter or calculation module

F3

calculation module wheel contact

F4

calculation module for correction value Ly

F5

calculation module brake pressure

F51

calculation module drive torque

F6

filter and / or regulatory module

F7

slip controller

F8

calculation module actual slip

F9

calculation module road friction Left

F10

calculation module Road friction value right

F11

comparison module

F12

calculation module

F13

calculation module Target slip determination

F14

calculation module Target slip determination

FL

wheel contact, wheel load

FL1L

wheel contact Left

FL1R

wheel contact right

frr

wheel braking, right

Miss

wheel braking, Left

Frrsoll

individual wheel Target braking force, right

Frlsoll

individual wheel Target braking force, left

H

Distance, height

K

subtraction

K1

Air spring stiffness in the rest position of the air spring

K2

wheel load, Radaufstandskraft in the rest position

Ly1

correction value

Ly2

Correction value, foresighted

MB

wheel braking

MBr

wheel braking right

MBl

wheel braking Left

nrad

vehicle wheel

Si

actual slip

Sir

actual slip right

Sil

actual slip Left

srad

Speed sensor

ss

setpoint slip

ssr

setpoint slip right

ssl

setpoint slip Left

y1

Manipulated variable actuator before correction

Syk1

Control value brake actuator after correction

Syk2

Actuating variable accelerator actuator to correction

x

longitudinal direction

X1

steering angle steering wheel

X21

angle of deflection accelerator

X2

Brake pedal position

X3

brake pressure

X31

Drive torque request

Y1

effective Manipulated variable on the brake actuator

Y11

effective Manipulated variable on the acceleration actuator

μxr

road friction, right

μxl

road friction, Left

Claims (13)

Method for motor vehicles with a Radschlupfregelsystem, which has means for detecting the wheel slip on one or more vehicle wheels, a Radschlupfregler that generates one or more individual wheel variables (Sy1), and one or more actuators (AktB, AktC), with which the wheel slip can be changed with the wheel-individual manipulated variable (Sy1), characterized in that at least one wheel-specific manipulated variable (Sy1) of the wheel slip controller by a wheel rollover force (FL) on the corresponding wheel representing correction variable (Ly 1) to a new manipulated variable (Syk1, Syk2) for the actuators (AktB, AktC) is changed. Method according to claim 1, characterized in that that the manipulated variable (Syk1, Syk2) for the brake actuator (AktB) and / or the acceleration actuator (AktC) with the determined braking and / or acceleration specification (X3, X31) of the driver linked (added or subtracted), resulting in an effective manipulated variable (Y1, Y11) for the brake actuator (AktB) and / or the acceleration actuator (AktC) results. Method according to claim 1 or 2, characterized that for determining the correction quantity (Ly 1) at least one the wheels the distance (H) of the vehicle body from the wheel axle or the Distance between the vehicle floor and the lane detected and is being used. Method according to one of the preceding claims, characterized characterized in that the correction quantity (Ly2) influences the influence of future changes the wheel contact force (FL). Method according to one of the preceding claims, characterized characterized in that for determining the correction quantity (Ly2) the steering angle (X1) of the vehicle steering is detected and used. Method according to one of the preceding claims, characterized characterized in that the correction quantity (Ly1, Ly2) is an increase in the Value of the manipulated variable (Syk1, Syk2) for the actuator (AktB, AktC) causes or allows, if the future expected wheel contact force (FL) will become larger, respectively leads to a reduction of the manipulated variable (Syk1, Syk2), if the future expected wheel contact force (FL) will be lower. Method according to one of the preceding claims, characterized characterized in that the desired slip (Ss) at one or more wheels in dependence of Wheel contact forces (FL) determined on at least one wheel changed is, where the target slip (Ssl, Ssr) for each of the wheels can be different sizes. Method according to one of the preceding claims che, characterized in that from one or more a Radaufstandskraft (FL) representing quantities (Ly1, Ly2) wheel-individual braking and / or traction forces are determined, which describe the adhesion between the road and the tires. Method according to one of the preceding claims, characterized characterized in that from the axis comparison of the determined wheel-specific braking and / or traction forces that wheel selected becomes the lowest braking and / or traction force, and that the target slip (Ssl, Ssr) on the other wheel at the same Vehicle axle is lowered so that the occurring there Braking and / or traction force is the same size. Method according to one of the preceding claims, characterized characterized in that from the axis comparison of the determined wheel-specific braking and / or traction forces that wheel selected becomes the lowest braking and / or traction force, that the target slip (Ssl, Ssr) on the other wheel at the same Vehicle axle is lowered so that the occurring there Braking and / or traction force equal to the former Rad is, and that over a delay element the nominal slip (Ss) on the wheel at which the nominal slip (Ssl, Ssr) was lowered, the braking and / or traction force back to those Value increased is, this had before the Sollschlupfabsenkung. Method according to one of the preceding claims, characterized characterized in that these variants of the method are then used when the yaw rate of the vehicle does not exceed a predetermined threshold. Method according to claim 11, characterized in that that when crossing a yaw rate threshold the wheel-specific brake and / or traction forces on at least one of the wheels that the manipulated variable (Syk1) is for the Brake actuator (AktB) is increased at the wheel through which a Yawing opposite torque is exerted on the vehicle, and that the manipulated variable (Syk1) is reduced at that wheel on which a yaw supporting Torque is applied to the vehicle. Method according to one of the preceding claims, characterized characterized in that this as a separate control and regulatory procedure operated in a control and regulating device of a motor vehicle or part of a control program an antilock braking system, a traction control system and / or a driving stability control system in a motor vehicle.