WO2009097947A1

WO2009097947A1 - Method and device for influencing an active chassis

Info

Publication number: WO2009097947A1
Application number: PCT/EP2009/000156
Authority: WO
Inventors: Ralph Streiter
Original assignee: Daimler Ag
Priority date: 2008-02-06
Filing date: 2009-01-14
Publication date: 2009-08-13
Also published as: DE102008007657A1

Abstract

The invention relates to a method for influencing an active chassis of a vehicle, in which a roadway height profile (zs) located in front of the vehicle in the direction of travel (20) is determined and the active chassis is influenced in accordance with the detected roadway height profile (zs). From said roadway height profile (zs), a filtered height profile is formed in a filter step of the method with the aid of a filter instruction, and from said height profile, at least one structure desired variable describing the desired position and/or movement of the structure (12) of the vehicle is then determined. The roadway height profile (zs) in front of the vehicle is filtered when carrying out the filter step in the direction of travel (20) and counter to the direction of travel (20).

Description

Method and device for influencing an active

chassis

The invention relates to a method for influencing an active chassis of a vehicle, wherein a track height profile located in front of the vehicle in the direction of travel is determined and the active chassis is influenced as a function of the detected roadway height profile.

Such a method is known from US 6,233,510 Bl. The road condition is predetermined and used to influence the spring units of the vehicle. A sensor-for example a laser sensor or an image recognition sensor-detects the road surface in front of the vehicle and transmits the sensor data to a control unit, which predetermines the roadway height profile lying in front of the vehicle in the direction of travel. Depending on this lane height profile, an active suspension system with multiple spring or damper units is affected and the spring rate, damping rate, pressure, level, etc. are controlled or regulated.

Based on this, it is an object of the present invention to further improve the ride comfort for the vehicle occupants.

This object is achieved by a method in which from the roadway height profile in a filtering step of the method using a filter specification a filtered height profile is formed from the subsequently at least one the desired position and / or movement of a vehicle body of the vehicle descriptive body target size is determined, wherein the lying in front of the vehicle roadway height profile is filtered in the implementation of the filter step in the direction of travel and against the direction of travel.

With the aid of the filtering of the roadway height profile, the nominal body size can be determined in a simple way. Characterized in that the roadway height profile is filtered both in the direction of travel and against the direction of travel of the vehicle, a movement of the vehicle body can be adjusted, which is not only caused reactive upon reaching a road bump, but begins before reaching the obstacle and the comfort of the vehicle occupants significantly increases.

Advantageous embodiments of the method emerge from the dependent claims.

It is advantageous if the determined roadway height profile is time-dependent and is determined from the path-dependent roadway sensor data of a roadway sensor and the vehicle longitudinal speed. In particular, a path-dependent roadway height profile can be sensory measured from the then from the current vehicle longitudinal speed, a time-dependent roadway height profile is calculated.

In this case, a chassis control variable for influencing the active chassis can then be determined as a function of the roadway height profile and / or the nominal body size in order to adapt the chassis settings to optimize the driving comfort.

Furthermore, it is possible to determine the position of the chassis and / or the movement the vehicle body descriptive and temporally compared with the determination time past past body size to be considered. As a result, abrupt position or movement changes of the vehicle body are avoided.

In addition, it is advantageous if, in the determination of the chassis control variable, the time taken by the time of the determination is already taken into account by at least one vehicle lane overrun past lane height profile, whereby the comfort can be further improved.

In an advantageous embodiment, the chassis control variable is limited to a predefinable control range to improve comfort.

In order to optimize the process cyclically, an optimization process for optimizing at least one filter parameter can be carried out before or after the filtering step in each process cycle.

Expediently, the optimization method defines at least one optimization variable, in particular an optimization vector, which describes or has at least one comfort parameter relevant to the comfort of the vehicle. The optimization variable, in particular the

Optimization vector to describe or have the chassis control variable. It is advantageous if the comfort parameter describes a body acceleration and / or a body speed of the vehicle body in the height direction. By these measures, a comfort-oriented adaptation of the method can be achieved in each cycle.

By defining a target variable, in particular a target vector, which specifies a desired value for the optimization variable for the optimization method, it is possible to carry out the optimization method in such a way that the vehicle occupants noticeable improvements in ride or suspension comfort can be achieved. In particular, the target variable, in particular the target vector, is limited to a target value range relevant for the comfort, in order to avoid unnecessary adjustments.

It is also advantageous to adapt the target variable to the current value of the optimization variable if the current optimization variable has a better driving comfort value that lies outside the target value range. Thereby, a change of the optimization amount to the comfort deteriorating values can be prevented.

The provision of a weighting variable-in particular of a weighting vector-for the target variable, in particular the target vector, wherein the weighting variable is changed as a function of the current optimization variable and / or the current target variable, makes sense in particular when using a target vector. The target vector values may result in a target conflict that may be resolved by introducing the weighting quantity, in this case a weighting vector.

In a further method variant, a change variable, in particular a change vector or a change matrix, can be defined which describes the dependence of the optimization variable on the change of the at least one filter parameter to be optimized. With the aid of the change variable, it is possible to determine a prognosis value for the optimization variable when the at least one filter parameter is changed by a filter parameter change value. The change variable therefore represents the basis for determining the prognosis value. The at least one filter parameter change value can be determined such that the prognosis value for the optimization variable is closer to the target variable than the current optimization variable. In this way, the optimization variable cyclically approaches more and more to the target size. The difference between the optimization size and the target size decreases.

In this case, it is possible to carry out the determination of the at least one filter parameter change value as a function of the weighting variable, as a result of which a very targeted optimization of the at least one filter parameter can take place.

On the basis of the last used at least one filter parameter and the filter parameter change value, a new filter parameter for the next filter step can be determined in order to improve the filtering in the subsequent filtering step.

In the following, an embodiment of the method will be explained in more detail with reference to the accompanying drawings. Showing:

Fig. 1 is a schematic representation of a part-vehicle model with wheel, spring or damper unit and

Vehicle structure, Fig. 2a is a partial schematic representation of a first active suspension system with spring or

Damper unit, Fig. 2b is a partial schematic representation of a second active suspension system with spring or

Damper unit, Fig. 3 is a flowchart of an embodiment of a

4 shows a flowchart of a method part of the

Method of Fig. 1 for determining a

FIG. 5 is a flow chart of an optimization method as

Process part of the method of FIG. 2 and FIG. 6 is a schematic diagram of the phase-free

Filtering in the filtering step of the process. FIG. 1 shows a schematic representation of a partial vehicle model, with a vehicle wheel 10, the controllable spring or damper unit 11 associated with this vehicle wheel 10 and the vehicle body 12 shown as a mass, which has a vehicle center of gravity 13. The part-vehicle model represents only that part of the entire vehicle that is relevant for one of the vehicle wheels 10 and applies, for example, to a car with two axles for each of the four vehicle wheels 10 and for the four spring or damper units 11.

This part-vehicle model is related to one. stationary coordinate system 14. zs (x) denotes the path-dependent roadway height profile of the roadway, the path x representing the abscissa of the coordinate system 14 and the roadway height profile zs (x) being measured in the direction of the vehicle's vertical axis. The construction position of the vehicle center of gravity 13 seen in the direction of the vehicle vertical axis is provided with the reference numeral zA.

The current actual level of the spring or damper unit 11 can be adjusted or changed by the activation of an actuator 11 'of the spring or damper unit 11. All spring or damper units 11 of the active chassis are controlled by a control unit 20. The control unit determines the setting for the spring or damper units 11, inter alia, on the basis of sensor data and, in particular, the sensor data of a roadway sensor 21, which detects the path-dependent roadway height profile zs (x) located in front of the vehicle in the direction of travel 20.

The roadway height profile zs (x) may be different for each vehicle side and possibly for each vehicle wheel 10 and correspondingly detected by a plurality of scanning units of the roadway sensor 21 at different locations of the vehicle. The actual levels can be on all spring or damper units 11 and Fahrzeugrädern 10 differ. Therefore, these quantities are determined or set separately for each of the spring or damper units 11.

About the control unit 20, the vehicle wheels 10 of a vehicle, not shown, associated active spring or damper units 11 are controlled independently of each other to affect the construction position zA of the vehicle body 12 in the range of all vehicle wheels 10.

The influencing or regulation of the construction position zA and / or the movement of the vehicle body 12 can take place in all dimensions. Thus, the pitch and / or roll and / or hitching, as well as the wheel contact forces of the vehicle wheels on the road surface can be influenced, controlled or regulated. As a result, a tension of the chassis can be achieved for example between the front and rear axle of the vehicle. In particular, the RadaufStandskräfte two diagonally opposite vehicle wheels opposite the wheel contact forces of the other two diagonally opposite vehicle wheels can be increased or decreased. In this way, the lateral dynamic behavior of the vehicle can be influenced.

FIGS. 2 a and 2 b show two examples of active suspension systems schematically with reference to a vehicle wheel 10 in a partial representation. As a spring or damper unit 11 there active spring or damper units IIa and IIb are provided with adjustable springs. Alternatively or additionally, active spring or damper units 11 with adjustable dampers could also be used.

FIG. 2 a shows an active hydropneumatic spring or damper unit IIa with a pressure source 60 and a reservoir 61, each of which is fluidically connected to an electrically controllable spring valve 62. The spring valve 62, depending on its valve position, either the pressure source 60 or the reservoir 61 with a pressure chamber 63 of a piston-cylinder unit 64, which represents the actuator 11 'of the hydropneumatic spring or damper unit IIa, connect fluidly or interrupt all fluid connections, so that Actual level y of the hydropneumatic spring or damper unit IIa can be increased, reduced or kept constant. With the pressure chamber 63, a working space 66 of a compressed gas tank 67 is connected via a throttle 65. The working space 66 is separated from a compressed gas space 68 by a flexible membrane. The compressible compressed gas in the compressed gas chamber 68 provides in the hydropneumatic spring unit IIa for the spring action. The throttle 65 causes a damping. The piston-cylinder unit 64 and the compressed gas tank 67 represent the adjustable spring 64, 67 represents.

Another form of active suspension or damper unit 11 of an active suspension system is shown in Fig. 2b, which may be referred to as ABC spring unit IIb, where "ABC" stands for "Active Body Control". The same components with respect to the hydropneumatic spring unit IIa are provided with the same reference numerals. In contrast to the hydropneumatic spring unit IIa, the ABC spring unit IIb has no pressurized gas container 67. The ABC spring unit IIb has a series arrangement of a coil spring 70 with the piston-cylinder unit 64, wherein this series circuit forms the adjustable spring 64, 70 of the spring or damper unit IIb. Parallel to this adjustable spring 64, 70, a separate damper 71 is provided. As with the hydropneumatic spring unit IIa of the pressure chamber 63 can be filled to the piston-cylinder unit 64 via the spring valve 62 be drained or be locked _{so as} to adjust the actual level y of the ABC spring unit IIb corresponding to a target level of y n. In the following, an embodiment of a method for controlling an active chassis of a vehicle or its spring or damper units 11 will be explained in detail with reference to FIGS.

The illustrated in the figures 3 to 5, preferred method is used to determine the position of the vehicle body 12 depending on sensory detected roadway height profile zs (x). Analogously, it would also be conceivable alternatively or additionally to regulate further positions or movements of the vehicle body 12, such as the pitch or the roll.

In a first step 100, the path-dependent roadway height profile zs (x) in the direction of travel 20 in front of the vehicle is detected by the roadway sensor 21. The path-dependent roadway height profile zs (x) can be represented as a vector whose individual values each correspond to a height profile value at a measuring point on the roadway. In the exemplary embodiment described here, n measuring points are provided so that the vector of the path-dependent roadway height profile zs (x) has a number of n vector values:

^ZS ( ^X k ₊ n)

zs (x) = zs ( _{xk + 2} ): D

^ZS ( ^X k ₊ 1) zs (x _k )

Taking into account the relationship between the path and the time using the vehicle longitudinal speed v _x

^x k = h- ^v _x (2! the time-dependent roadway height profile zs (t) can be determined in the second step 105:

In a third step 110, a design target variable zA is determined _as n (t) in a method part, as will be explained in detail later in connection with FIG. The superstructure setpoint zA _so n indicates, for example, how the position of the vehicle body 12 should result as a function of time, thus the desired stroke position or lifting movement of the vehicle body is set by the superstructure setpoint zA _so ii.

The construction target size is also given here as a vector with n entries:

The buildup position zA of the vehicle body 12 at a time t * depends on the buildup position before the time of observation t _k , on the road height profile zs (t≤t _k ) until the time of observation t _k and on the manipulated variables u (t _k ) of the active spring or Damper units 11 of the vehicle. The construction position zA can, taking into account the dependencies described by a Vehicle model will be described. The vehicle model can be set up by test drives and simulations.

On the basis of this vehicle model, the future body movement zA (t> t _k ), which will take place after the time of observation t _k , can also be predicted. For this, however, the future manipulated variables u (t> t _{k + n} ) would have to be known. However, if the desired body size zA _so n specifies the desired build position or body movement and the lying in the direction of travel 20 in front of the vehicle lane height profile zs is known, the future manipulated variables for the spring or damper units 11 can be determined. The following equation is used for this purpose:

M _7Λ (5)

in which

MzA- is the matrix of coefficients for the current and future construction position,

M 'A; B: the matrix of the coefficients for the future

Buildup position is,

Mc is the matrix of the coefficients for the future and optionally also lying roadway height profile,

M _u : the matrix of the coefficients for the current and future manipulated variables for the spring or

Damper units 11 to the level and / or

Damper setting, indicating the current and future construction position,

zA (t _k _ ₂ ): indicates the build-up position past the observation time t * zA {t _k _ _λ ),

zs {t _k _ _y ) zs (t _k _ ₂ )

: that compared to the time of observation t _k zs {t _k ) past, the current and the future

∞ ('* ₊ l) indicates the lane height profile, and

: indicates the current and future location quantities for the spring or damper units 11 of the vehicle.

The matrices M _zA , M _AB , M ₃ and M _u are part of the determined vehicle model. From the requirement:

obtained together with equation [5]

(7)

In this way, in a fourth step 115, future manipulated variables u (t> t _k ) in the form of the vector specified for equation (7) are determined for n points in time as a function of the vectorial setpoint variable zA _so n from the third step 110 of the method. The vectorial manipulated variable u (t) according to equation (7) indicates how the spring or damper units 11 of the vehicle must be adjusted in order that the buildup position zA (t) corresponds to the design target position ^z A _S oii (t), if the vehicle in Direction of travel 20 ahead of the vehicle lying roadway height profile zs (t) moves over.

In a fifth method step 120, residual reactions and boundary conditions are considered, to which the spring or Damper units 11 of the vehicle subject. In simplified terms, this can be represented as follows:

umin <u (t _{k + 2} ) <umax (8)

"( '* +")

Such restrictions stem from the fact that the adjustment path for the levels y of the spring or damper units 11 is limited. In addition, there are restrictions on the flows of the spring valves 62. The size of the valve flows of the spring valves 62 also serves as a measure of the energy requirements, which is also subject to restrictions.

Finally, in the sixth step 125, the manipulated variables for the spring or damper units 11 of the vehicle are set by the control unit 20. Subsequently, the method starts again with the first step 100 and is thus carried out cyclically during vehicle operation.

On the basis of Figure 4 will be explained in detail below, as is done to determine the vectorial structure desired size zA _as n (t) in the third process step 110th The processed in the third step 110 process part is shown in Figure 4. The core idea for determining the set target size zA _so n (t) is to phase-filter the ascertained road-height profile zs (t) in a filter step 200 using a filter rule P. From this one obtains the filtered roadway height profile zsP (t):

with f: filter frequency

D: Filter damping Any filter functions, for example based on a PTχ element or a PT ₂ element, can serve as the filter specification P. The peculiarity of the phase-free filtering in the method according to the invention lies in the fact that the filtering of the road height profile zs (t) takes place both in the direction of travel 20 of the vehicle, and counter to the direction of travel 20 of the vehicle and then the filtered road height profile zsP is determined. This is shown schematically in FIG. It is assumed by way of example that the roadway height profile zs (t) has a road surface unevenness in the form of a step-like course. With zsPl (t), the filtering in the direction of travel 20 is shown in dashed lines, while the filtering opposite to the direction of travel 20 is shown dotted with zsP2 (t). From these two filters zsPl and zsP2 in and counter to the direction of travel 20, the filtered roadway height profile zsP (t) is then determined, for example, by averaging. It can be seen that due to the phase-free filtering in two directions a filtered roadway height profile zsP (t) is obtained, the road bumps, so to speak "anticipate" because they can already be considered due to the time course of the filtered roadway height profile zsP (t) Therefore, taking the road height profile zsP (t) into account, it is possible to set the spring or damper units 11 of the active chassis of the vehicle to the road even before reaching a road surface unevenness and thus anticipate the road surface unevenness Way, the comfort of the vehicle occupants can be significantly increased.

Decisive variables for the filter specification P are the filter frequency f and the filter damping D. The filter frequency f and the filter damping D serve as parameters for adapting the setting of the filter specification P to the vehicle or system properties of the active chassis and the best possible comfort behavior adjust. In this case, a filter rule P higher order should be used. By filtering both in and counter to the direction of travel 20, which could also be referred to as "forward-backward filtering", the active vehicle tends to bring the vehicle body 12 in a suitable and favorable for the comfort of movement direction even before reaching the road surface 6. The roadway unevenness is as it were smoothed, as can also be recognized by the schematic illustration in Figure 6. How pronounced this smoothing of the roadway height profile zs is depends on the filter frequency f and the filter damping D. In principle, the ascertained roadway height profile zs (t) the greater the filter frequency f and the filter damping D are selected, reducing the build-up accelerations of the vehicle body 12, thereby increasing the comfort for the vehicle occupants, but no increase in the filter frequency f and the filter loss D m Possibly, since both the active chassis of the vehicle, as well as the control unit 20 are subject to limitations or restrictions and the actuating speeds of the actuators 11 'and the computing power of the control unit 20 are not arbitrarily large.

After the filter step 200, the design target variable zA _{is determined} n (t) on the basis of the filtered roadway height profile zsP (t) in a determination step 205. In the preferred embodiment, the design target size zA _is n (t) the filtered roadway height profile zsP (t).

In order to improve the comfort during operation of the vehicle, after the determination step 205, an optimization method 210 is performed, which is illustrated in FIG. Thus, during each cycle of the method according to the invention, the optimization process 210 is run through, so that the comfort during the driving operation is continually and continually optimized. After the start of the optimization method 210, an optimization variable r is defined in a first optimization step 300, which is specified in the form of an optimization vector with four vector elements _r r r ₂ , r ₃ , r ₄ , for example:

Accordingly, the optimization vector r is composed of the comfort characteristic parameters ri, r ₂ and the restrictions of the active chassis characteristic vector quantities r ₃ , r ₄ together. The two as

Comfort characteristics vector elements ri, r ₂ in the preferred embodiment described herein include the build target acceleration resulting from the build target size zA _so n by forming the difference in build target speeds at successive times. The superstructure target speeds result by time derivative of the superstructure target position zA _so ii (t). The optimization vector r could also contain further variables characterizing the comfort, such as, for example, the body speed or other boundary conditions and restrictions.

Comparison with zero in the minimum and maximum calculations ensures that a result of a maximum calculation can not become negative, or a result of a minimum calculation can not be positive. As a result, this always means that one of the two entries ri or r ₂ or one of the two entries r ₃ or r _{4 is} equal to zero. This division simplifies the further optimization process.

In a second optimization step 305, a target size J is defined for the optimization variable r. Since, for example, the optimization variable is a vector, the target variable is also predetermined as the target vector J. Starting from the optimization vector r, the two vector values ri, r _{2 should be} as small as possible, since then the build-up acceleration is low and the comfort is very high. The two vector elements r ₃ , r ₄ describing the restrictions of the landing gear must comply with predetermined limit values which can be defined as the target variable. In the preferred embodiment described here, therefore, the target vector J is specified as follows:

ar, ar ₂

J = with α <1 (11) abs {umax) abs (u min)

The fact that the value for the factor α is smaller than 1 describes the goal of reducing the build-up accelerations described with the two vector values ri, r _{2 of} the optimization vector r. As an optimization of the Comfort is only useful if the improvement within the procedure for the vehicle occupants is noticeable, end goals must be defined so that an optimization of the regulation outside the felt for the vehicle occupant area is avoided. Therefore, the target vector J is extended according to example to:

^/ i) max (k _size:, a - r ₂ )

J = with α <1 (12) abs {u max) abs (u min)

The value k _size specifies the final destination, below which no further optimization should take place, since the sensing threshold for the vehicle occupants would be undershot.

A further improvement is achieved in the preferred embodiment by preventing adjustments that would lead to a deterioration of comfort. If a vector value of the optimization vector r is already smaller than the target defined by the corresponding vector value of the target vector J, the target is adapted to this vector value of the optimization vector r. For the target vector J follows:

mm [r _x , m∞i (k _boundary , a - r _x )] min [r ₂ , max (k _Oren :, a • r ₂ )]

J = with α <1: 13] min [r,, abs (u max)] min [r ₄ , abs (u min)]

In the preferred embodiment, the target vector J is given according to equation (13) in the second optimization step 305. It is understood that, alternatively, a target vector according to one of the two equations (11) or (12) could be used. In the subsequent third optimization step 310, a weighting variable g is specified, which is given by way of example as the weighting vector g with four vector elements gi, g ₂ , g ₃ , gi. As start value, all vector elements gi, g ₂ , g ₃ , g _{4 of} the weighting vector g are set to 1. Each time the third optimization step 310 is performed, the vector elements of the weighting vector g are adjusted as a function of the target vector J and the optimization vector r. The following rules apply to the adaptation: the vector element q ^ is lowered if the corresponding vector element r _{± of} the optimization vector is smaller than the vector element J _{1 of} the target vector. The vector element gi of the weighting vector is increased if the corresponding vector element ri is greater than the vector element J _{1 of} the target vector. Was the vector element r _{1 / ait of} the optimization vector r in the previous process cycle smaller than the corresponding vector element J _{1 of} the target vector J and is the vector element r _{1 (} n _{eu of} the optimization vector r in the current process cycle but larger than the corresponding vector element J _{± of} the target vector J, _. the associated vector element of the weighting vector g ^ g is equal to 1 is set to follow apply.:

g _,, _new = g _{,, Ot1} - P ^for ri, _new <J ₁ and 0 <ß <1 (15)

g _ljm , = ^ f- for r _{lf lM} ^, u> J ₁ and 0 <ß <1 (16) g, " _eιl = \ for r _lf ait <Ji and ri, _new > J ₁ (17)

where i = 1, 2, 3, 4. The vector values gi, _{new of} the current process cycle are normalized to their maximum, so that the following results for the weighting vector in the third optimization step 310:

Subsequently, in a fourth optimization step 315, a change variable and, for example, a change matrix Degree is defined which describes a relationship between the optimization vector r and the filter parameters to be optimized, ie the filter frequency f and / or the filter damping D. In the embodiment, the change matrix degree is as follows:

^~ dr _x dr _χ - dD df dr ₂ dr ₂

Degree - dD df (19) dr ₃ dd df dr ₄ dr ₄ dd df

The change matrix degree therefore contains in each column as many matrix elements as the optimization vector r has vector elements. The number of columns of the change matrix degrees corresponds to the number of filter parameters to be optimized. In the present case, two columns are provided, since both the filter frequency f, and the filter damping D to be optimized. Each matrix element of the change matrix degree contains a derivative of a Vector element r _{± of} the optimization vector r, derived according to the relevant filter parameter f or D.

Starting from the change _{matrix D} r, the following prediction _value r _prog for the optimization vector r is given in a simplified and, _according to the example, locally linearized approach:

AD prog = r + degrees (20)

Δ /

On the basis of this approach filter parameter change values ΔD, Δf for the filter damping D or the filter frequency f can be determined, the prognosis _value r _prO g enabling a prediction as to how the optimization vector r changes as a function of the filter parameter change values ΔD, Δf. The simplified approach to the prediction _value r _prO g enables a real-time calculation during operation of the vehicle.

By equating the prediction value r _prog with the target vector J, it is predetermined that the prediction value r _prog approaches as close as possible to the target vector J. The equation is then multiplied on both sides by the weighting vector g extended to the diagonal matrix diag (g). After a mathematical transformation, the equation can then be solved for the filter parameter change values ΔD, Δf, where the following equation results:

^ = (diag (g) ^■ GradJ [diag (g) • degrees] ^'1 [diag (g) ^■ degrees] ^{1 ■} diag (g) ^■ (J - r)) (21)

Finally, in a sixth optimization step 325, the new filter frequency f _new and the new filter damping D _ne u for the next process cycle can be determined as follows:

D _mu = D _alt + relax • AD with relax <1 (22)

^with relax <1 ⁽ 23 ⁾

The relax factor is used for the gradual slow adaptation of the filter parameters.

Subsequently, the optimization process 210 is terminated and thus also the determination of the built-in setpoint zA _so iκt) completed in accordance with Figure 4. The method according to FIG. 3 is then continued in the fourth method step 115 and further cycled.

Claims

claims

1. A method for influencing an active chassis of a vehicle, wherein a in the direction of travel (20) in front of the vehicle located roadway height profile (zs) determined and the active chassis is influenced depending on the detected roadway height profile (zs), characterized in that from the roadway height profile (zs ) in a filter step (200) of the method with the aid of a filter specification (P) a filtered height profile (zsP) is formed from which subsequently at least one the desired position and / or movement of a vehicle body (12) of the vehicle descriptive body target size (zA _so ii ), wherein the road height profile (zs) lying in front of the vehicle is filtered during the execution of the filter step (200) in the direction of travel (20) and counter to the direction of travel (20).

2. The method according to claim 1, characterized in that the determined roadway height profile (zs (t)) is time-dependent and from the path-dependent road sensor data (zs (x)) of a road sensor (21) and the vehicle longitudinal speed (v _x ) is determined.

3. The method according to any one of claims 1 or 2, characterized in that a Fahrwerkstellgröße (u (t)) for influencing the active chassis depending on the roadway height profile (zs (t)) and / or the construction target size (zA _so n (t)) is determined.

4. The method according to claim 3, characterized in that in determining the Fahrwerkstellgröße (u (t)) a position and / or movement of the vehicle body (12) descriptive and temporally compared with the determination time (t _k ) past past body size is taken into account ,

5. The method according to claim 3 or 4, characterized in that in the determination of the Fahrwerkstellgröße (u (t)) the time up to the determination time (t _k ) already by at least one vehicle wheel (10) traveled past roadway height profile is taken into account.

6. The method according to claim 4 or 5, characterized in that the Fahrwerkstellgröße (u (t)) is limited to a predetermined setting range (umin, umax).

7. The method according to any one of claims 1 to 6, characterized in that in each process cycle before or after the filtering step (200), an optimization method (210) for optimizing at least one filter parameter (f, D) is performed.

8. The method according to claim 7, characterized in that in the optimization method (210) at least one optimization variable (r), in particular a

Optimization vector is defined, which describes or has at least one relevant for the comfort of the vehicle comfort parameter (ri, r ₂ ).

9. The method of claim 8 in conjunction with one of claims 3 to 6, characterized in that the optimization variable (r), in particular the optimization vector, the chassis control variable (u (t)) describes or has.

10. The method according to claim 8 or 9, characterized in that the comfort parameter (ri, r ₂ ) describes a body acceleration and / or a body speed of the vehicle body (12) in the height direction.

11. The method according to any one of claims 8 to 10, characterized in that for the optimization method (200) a target size (J), in particular a target vector, is defined, which indicates a desired value for the optimization size (r).

12. The method according to claim 11, characterized in that the target size (J), in particular the target vector, is limited to a relevant for the comfort target value range (k _G ).

13. The method according to claim 11, wherein the target variable is adapted to the current value of the optimization variable if the current optimization variable has a better driving comfort value that is outside the target range (k _G ). lies.

14. The method according to any one of claims 11 to 13, characterized in that a weighting variable (g), in particular a weighting vector, for the target size (J), in particular the target vector, is predetermined, wherein the weighting quantity (g) depends on the current optimization size (r) and / or the current target size (J) is changed.

15. The method according to any one of claims 8 to 14, characterized in that a change quantity (degree), in particular a change vector or a change matrix is defined, the dependence of the optimization size (r) on the change of the at least one filter parameter to be optimized (f, D) describes.

16. The method according to claim 15, characterized in that with the aid of the change _quantity (degree) a prognosis _value (r _prO g) for the optimization _variable (r) is determined, wherein the at least one filter parameter (f, D) by one

Filter parameter change value (.DELTA.f, .DELTA.D) is changed.

17. The method according to claim 16, characterized in that the at least one filter parameter change value (.DELTA.f, .DELTA.D) is determined such that the forecast _value (r _prO g) for the optimization _quantity (r) is closer to the target size (J) than the current optimization quantity (r).

18. The method according to claim 17 in conjunction with claim 14, characterized in that the determination of the at least one

Filter parameter change value (.DELTA.f, .DELTA.D) depending on the weighting variable (g) takes place.

19. The method according to claim 17 or 18, characterized in that based on the last used at least one filter parameter (D _alt , f _a it) and the filter parameter change value (.DELTA.f, .DELTA.D) a new filter parameter (D _new , fnew) for the next filter step (200) is determined.