DE102012014890A1 - Recognizing a loading state of a motor vehicle by measuring a hydraulic pressure - Google Patents

Abstract

It is a method for detecting an actual state (9) of a motor vehicle (1), wherein the motor vehicle (1) between a wheel (3) and a body (5) of the motor vehicle (1) acting hydraulic actuator device (7) , full:
Determining an actual hydraulic variable describing an actual hydraulic state of the actuator device (7),
proposed.
In order to enable the most accurate determination of an actual load state of the motor vehicle, the steps are:
- Measuring at least one in the actuator device (7) occurring hydraulic actual pressure (11) by means of one of the actuator device (7) hydraulically associated pressure measuring device (13) for determining the actual hydraulic variable and
Detecting an actual loading state (15) of the motor vehicle (1) as a function of the at least one hydraulic actual pressure (11) of the actuator device (7)
carried out.

Description

The invention relates to a method for detecting a loading state of a motor vehicle and a motor vehicle according to the method with a wheels having wheels, which has per wheel acting between the respective wheel and a body of the motor vehicle hydraulic actuator.

The detection of a loading state of a motor vehicle is known. Furthermore, it is known to determine a state of a motor vehicle in order to regulate and / or control a hydraulically activatable chassis of the motor vehicle. For this purpose, measuring methods and / or observer models can be used. In addition, it is known to take advantage of the running characteristics of wheels of a motor vehicle, which depend on an air pressure and a loading state, to draw conclusions about the loading condition. The DE 10 2007 047 399 B4 relates to a corresponding method for detecting a load condition of a motor vehicle, in which by means of wheel sensors in each case a wheel speed for each of the wheels of the motor vehicle and speed differences between the wheel speeds of the wheels are determined, wherein by means of a direct measuring tire pressure monitoring system, a first tire pressure in each of the wheels is measured, wherein a second tire pressure for each of the wheels is estimated based on the speed differences using a map and wherein at least one center of gravity of the motor vehicle is determined by a comparison between the first tire pressure and the second tire pressure. The DE 10 2010 007 237 A1 relates to a suspension system for a vehicle with a hydraulic actuator and a hydraulic fluid receiving memory, wherein between the memory and actuator, a motor pump unit is arranged, which is able to promote the hydraulic fluid from the actuator in the memory or from the memory in the actuator, provided in that the motor pump unit is controlled by a computing / control unit.

The object of the invention is to provide the most accurate and rapid method for detecting a loading state of a motor vehicle, in particular for a motor vehicle having a hydraulically activatable suspension. The object is in a method for detecting an actual state of a motor vehicle, the motor vehicle having a hydraulic actuator device acting between a wheel and a body of the motor vehicle, with determining an actual hydraulic variable describing an actual hydraulic state of the actuator device by measuring at least one in the actuator device occurring hydraulic actual pressure by means of one of the actuator device hydraulically associated pressure measuring device for determining the actual hydraulic variable and detecting an actual loading state of the motor vehicle as a function of at least one hydraulic actual pressure of the actuator device solved. Advantageously, the actual hydraulic pressure in the actuator device can be measured directly. Advantageously, the actual hydraulic state of the actuator device can thereby be determined comparatively quickly and accurately, in particular in comparison to methods which make use of indirect and / or estimated variables. This can be done in particular during a standstill of the motor vehicle or particularly advantageously during an operating state of the motor vehicle. Advantageously, a particularly accurate determination of the actual load state of the motor vehicle can take place on the basis of the quickly and exactly available measured value of the actual pressure. The actual state of the motor vehicle can be described by one or more currently directly and / or indirectly measurable arbitrary variables of the motor vehicle. In particular, the actual state also has the actual loading state.

An embodiment of the method is carried out according to claim 2. Advantageously, the detection of the actual loading state can also take place as a function of the reference state. In particular, it is possible to compare the reference state of the motor vehicle, which in particular also has a reference hydraulic state of the actuator device, with the actual hydraulic state, in particular the actual hydraulic pressure. Due to a difference, in particular pressure difference, it can be concluded that the actual load condition. In particular, a reference load state of the motor vehicle is defined in the reference state. The reference state of the motor vehicle is determined in particular at the factory and stored in a corresponding memory device of the motor vehicle retrievable. Alternatively or additionally, however, the reference state can also be read in by a user of the motor vehicle, for example when covering a reference path with a predefined and / or predefinable loading state, wherein the user of the motor vehicle can set this by corresponding operator inputs on the motor vehicle.

A further embodiment of the method is carried out according to claim 3. A loading of the motor vehicle can be understood as loading and / or unloading the motor vehicle with luggage and / or persons. After loading, in particular a weight and / or a center of gravity of the motor vehicle are thereby changed. Advantageously, this change can be detected. In particular, a reference level may be a relative position of the body of the motor vehicle to a road surface under standard conditions can be understood, in particular, a compression travel at a predetermined loading state below the reference level can be understood. The spring device is adapted and / or adapted to apply a force between the wheel and the body. In particular, such a force or spring force can be understood by the reference action of the spring device. The spring device itself can be designed in any desired manner, in particular as a passive spring device, in particular with a steel spring, in particular a spiral spring, be formed. Alternatively or additionally, the spring device may have an active spring device, in particular a pneumatic spring device, in particular an adjustable and / or variable internal pressure, wherein the reference effect, in particular a spring force and / or a jounce behavior and / or damping behavior of the air spring from within the air spring existing air pressure depends. Advantageously, the reference level can be set and / or held again after charging the motor vehicle. This can advantageously be done so that the other parameters, in particular the reference effect of the spring device, in particular if this is an active spring device, are kept constant. As a result, it is possible that an effect of charging solely by means of the actuator device is compensated such that thereafter the reference level is given again. Advantageously, and / or thereby also the reference action of the spring device can be adjusted and / or held so that it is constant. Advantageously, the hydraulic actual pressure of the actuator device can be measured after this process of loading and keeping constant the other parameters. Advantageously, by means of a comparison of the actual pressure during the reference state and after the loading, that is to say the restoration of the reference levels, to a force exerted by the actuator device between the wheel and the body force. This in turn can be used for detecting the actual loading state, in particular a change in a weight of the motor vehicle before and after loading. Alternatively or additionally, it is conceivable to include a temperature of the spring device to keep the reference effect of the spring device constant, if it is an air spring. In particular, a force of the reference action is kept constant before and after loading, so that an otherwise usually also produced via the spring device level compensation for detecting the actual load state can be temporarily switched off, advantageously measuring the actual pressure for detecting the actual Loading condition can be done. The actual pressure is measured in particular by means of at least one of the actuator devices. Alternatively, however, several, in particular all, of the actuator devices present in the motor vehicle can be used to measure at least one actual pressure, wherein in particular a position of a piece of luggage within the motor vehicle can also be deduced.

A further preferred embodiment of the method is carried out according to claim 4. In particular, the hydraulic reference pressure prior to loading and the actual pressure measured after loading can advantageously be compared with one another. In particular, a pressure difference can be formed. In particular, it is conceivable that a transmission behavior of the actuator device is known, with the aid of the transmission behavior of the differential pressure can be converted into a differential force before and after loading. Advantageously, with the aid of the then known differential force and the known reference loading state of the actual loading state can be detected. In particular, the actual load state deviates from the reference load state by a mass corresponding to the differential force.

A further preferred embodiment of the method is carried out according to claim 5. Advantageously, the method can also be used during a driving operation of the motor vehicle. In order to avoid possible scattering of the actual pressure due to body movements occurring during the driving operation of the motor vehicle body movements and / or at least to a minimum, an average value of the actual pressure for determining the mean pressure can be advantageously formed.

A further preferred embodiment of the method is carried out according to claim 6. Advantageously, the steering angle can be determined and / or measured during the driving operation of the motor vehicle. Alternatively or additionally, a driving speed of the motor vehicle can be determined in addition to the steering angle. The steering angle and the driving speed of the motor vehicle usually require a rolling movement of the body of the motor vehicle. This rolling motion represents the response of the motor vehicle. It is conceivable that this rolling motion is actively compensated by an actuating movement of the actuator device. Advantageously, a change of the actual pressure required for this purpose and / or an actual pressure occurring during this balancing of the rolling movement can be measured. Since the rolling motion or the response of the motor vehicle to the steering angle, in particular at a given speed, also depends on the actual loading state of the motor vehicle, in particular of a payload and a positioning of the payload, so a center of gravity can be closed by the actual pressure on the load condition of the motor vehicle. Alternatively or additionally, it is conceivable to measure the actual pressure as a static variable, in particular in the form of the mean pressure. Alternatively or additionally, however, it is also conceivable to measure the actual pressure as a course, wherein a transient response of the response of the motor vehicle to the steering angle can also be included in the detection of the actual load state. In particular, an oscillation behavior, in particular an oscillation frequency and / or an attenuation behavior, in particular an overshoot and / or an oscillation-free transient, allow conclusions to be drawn about the actual load state. In particular, this makes it possible to detect a roof load, in particular a loading of a roof box and / or a luggage carrier of the motor vehicle. This is advantageously possible because due to the driving dynamics of the motor vehicle at the predetermined speed and the steering angle forces in a transverse direction of the motor vehicle attack on this. It is conceivable, for example, to determine the actual pressure on the outer wheels. Alternatively or additionally, this can also be done analogously for pitching movements, ie by measuring and / or observing the actual pressure during a response of the motor vehicle to accelerations and / or decelerations in a longitudinal direction, ie braking and / or accelerating.

A further preferred embodiment of the method is carried out according to claim 7. Under a disturbance of the state of equilibrium can be understood in particular an active disturbance means of any adjusting device of the motor vehicle. In particular, interventions in a transverse and / or longitudinal dynamics of the motor vehicle, in particular braking interventions, interventions in an engine management, steering interventions, chassis interventions and / or the like, can be understood. Advantageously, it is not necessary to wait for a randomly suitable excitation, for example the steering movement and / or braking, which is triggered by the user of the motor vehicle, in order to recognize the actual loading state. Advantageously, the actual pressure during the response of the motor vehicle can be measured analogously to what has been described above, and from this conclusions about the actual load state can be drawn.

A further preferred embodiment of the method is carried out according to claim 8. Advantageously, the disturbance of the state of equilibrium can take place in particular by means of the actuator device and / or the active chassis of the motor vehicle itself. In particular, this can take place during a standstill of the motor vehicle, in particular directly at the beginning of a driving cycle. This can advantageously be done just before driving off. In particular, corresponding control interventions for disturbing the state of equilibrium can be carried out so gently and / or slightly that a user of the motor vehicle perceives this interference only comparatively weakly and / or not. Alternatively or additionally, it is conceivable to carry out the fault immediately upon actuation of a radio remote control, so that a corresponding user has not even entered the motor vehicle. Optionally, a corresponding body movement of the motor vehicle can be used simultaneously for a welcome of the user. Disturbing and / or measuring the actual pressure can be dynamic or static. In a static case, in particular, a tendency of the body can be made and measured in the steady state of the actual pressure. This can be done in particular in one of the actuator devices, which carries out the corresponding adjusting movement, which can be closed to the actual loading state together with a measure of the determined by the determined actual pressure deflection of the body. In a dynamic case, a vibration behavior can be determined.

The object is also achieved in a motor vehicle having a wheels having active suspension, which has per wheel acting between the respective wheel and a body of the motor vehicle hydraulic actuator device and a spring device, achieved in that at least one of the actuator devices comprises at least one pressure measuring device by means in which an actual hydraulic pressure acting in the actuator device can be measured, wherein an actual load state of the motor vehicle can be detected as a function of the actual pressure. The motor vehicle is in particular set up, designed and / or constructed for carrying out a method described above and / or has software suitable for this purpose. This results in the advantages described above.

Further advantages, features and details will become apparent from the following description in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. Described and / or illustrated features form the subject of the invention, or independently of the claims, either alone or in any meaningful combination, and in particular may additionally be the subject of one or more separate applications. The same, similar and / or functionally identical parts are provided with the same reference numerals.

Show it:

1 a schematic side view of an active chassis having motor vehicle;

2 a schematic detail view of an actuator device of the active chassis of in 1 shown motor vehicle; and

3 a schematic flow diagram of a method for detecting an actual loading state of in 1 shown motor vehicle.

1 shows a schematic side view of a motor vehicle 1 that an active suspension 29 having. The active chassis 29 used for springs and steaming a body 5 of the motor vehicle 1 , Between the body 5 and wheels 3 of the motor vehicle 1 is in each case an actuator device 7 connected. Each of the actuator devices 7 has a hydraulic actuator and a spring device 19 on. According to the presentation of the 1 it is the spring device 19 to a passive spring device, in particular a spiral steel spring. Alternatively or additionally, however, it is also conceivable that the spring devices 19 is designed as an air spring, in particular as an air spring with a variable internal pressure.

By means of the active chassis 29 of the motor vehicle 1 , in particular by means of the actuator devices 7 can a spring damper behavior of the motor vehicle 1 be actively influenced, in particular a roll stabilization are performed. A corresponding control of the actuator devices 7 takes place by means of a control device 61 , The control device 61 is in particular part of a central control, in particular of a control device of the motor vehicle 1 , This in 1 shown motor vehicle has an actual loading state. It can be seen that the motor vehicle 1 with a roof load 59 , in particular a roof box, is loaded. From the actual loading state of the motor vehicle 1 depends on a longitudinal and / or transverse dynamics, in particular by means of the active chassis 29 balanced and / or influenced. The active chassis 29 or the control device 61 are advantageously designed so that, despite the actual load condition of the motor vehicle 1 this has a similar as possible driving behavior. Advantageously, this can be the motor vehicle 1 or the control device 61 of the motor vehicle 1 , recognize the actual loading state and depending on the detected actual loading state control and / or control algorithms for driving the actuator devices 7 adapt and / or adapt.

2 shows a detailed view of one of the in 1 shown actuator devices 7 of the motor vehicle 1 ,

In the 2 shown actuator device 7 assigns the actor 31 and this parallel connected the spring device 19 on. The actor 31 is designed as a hydraulic actuator and has a longitudinally displaceable within a working cylinder 45 stored working piston 43 on. The working piston 43 is longitudinally displaceable and fluid-tight within the working cylinder 45 stored and so divides the working cylinder 45 in a first working chamber 39 and a second working chamber 41 , The working chambers 39 and 41 are each hydraulically connected to one of two outputs of a hydraulic pump generator 47 connected. The hydraulic pump generator 47 is designed as a bidirectional hydraulic pump and rotates in particular on a common shaft with an electric machine 49 , Both the electric machine 49 as well as the pump generator 47 are energetically bidirectionally operable, so that by means of the arrangement of the pump generator 47 and the electric machine 49 either the actuator device 7 Hydraulic energy can be supplied or removed from this. This can be bidirectional, so that depending on a control of the electric machine 49 an upward or downward adjustment movement of the wheel 3 by means of the actuator 31 is possible. By means of the pump generator 47 can be a pressure difference in the working chambers 39 and 41 be actively set, causing a compression or rebound of the wheel 3 leads.

The first working chamber 39 is a first gas storage 51 hydraulically assigned. The second working chamber 41 is a second gas storage 53 hydraulically assigned. At the gas stores 51 . 53 are hydraulic compliance points, by means of which in the actuator device 7 existing hydraulic energy can be converted into pneumatic energy, or vice versa.

It is also between the first working chamber 39 and the first gas storage 51 a first damper throttle 55 and between the second working chamber 41 and the second gas storage 53 a second damper throttle 57 connected. By means of the damper throttles 55 and 57 can a damping behavior of the actuator device 7 to be influenced. In particular, it is at the damper throttles 55 and 57 To adjustable hydraulic actuators, so that by a corresponding adjustment of the damper throttles 55 . 57 the damping behavior of the actuator device 7 is adjustable. The control is carried out in particular by means of in 1 shown control device 61 ,

Advantageously, the first working chamber 39 , the second working chamber 41 , the first gas storage 51 and the second gas storage 53 in each case at least one pressure measuring device 13 hydraulically assigned directly. Advantageously, corresponding actual pressures by means of the pressure measuring devices 13 be measured directly. In particular, in the first working chamber 39 an actual pressure p _K1 , in the second working chamber 41 an actual pressure p _K2 , in the first gas storage 51 an actual pressure p _SP1 and in that second gas storage 53 an actual pressure p _{SP2 be} measured. In particular, on the actuator device 7 at least one of the pressure measuring devices 13 intended.

The electric machine 49 in particular also by means of the control device 61 controlled and supplied with an actual current I _M and an actual voltage U _M and / or outputs this in a generator mode. Alternatively or additionally, it is conceivable to at least one of the pressure measuring devices 13 to dispense and, alternatively, an outlet pressure, in particular an outlet pressure difference of the pump generator 47 to calculate in dependence of the actual current I _M and the actual voltage U _M. Because the pressure difference of the pump generator 47 directly into the working chambers 39 and 41 can transfer to the working chambers 39 and 41 if necessary, one of the pressure measuring devices is dispensed with, wherein nevertheless the respectively not measured actual pressure can be determined as described above.

3 shows a schematic sequence of a method for detecting an actual loading condition 15 of in 1 shown motor vehicle 1 ,

In a first optional step 33 becomes a reference state 17 of the motor vehicle 1 provided and / or determined.

In a second step 35 becomes an actual state 9 of the motor vehicle 1 determined. This is at least one of the actual pressures 11 by means of at least one of the pressure measuring devices 13 , as in 2 shown, determined.

In a third step 37 becomes dependent on the determined actual state 9 and optionally additionally depending on the reference state 17 the actual loading condition 15 recognized.

According to a preferred alternative of the method, the reference state 17 a in 2 drawn reference level 21 on. In addition, the spring device 19 a likewise in 2 drawn reference effect 23 on. The reference effect may be a predetermined and / or predefinable spring force of the spring device 19 act. The reference level 21 and / or the reference effect 23 are also after a shop, in particular a loading and / or unloading of the motor vehicle 1 set and / or held. After loading and / or unloading, as described above, at least one of the actual hydraulic pressures 11 measured and based on the at least one actual pressure 11 the actual loading condition 15 recognized.

This is preferably done at a standstill of the motor vehicle 1 , Alternatively or additionally, however, this may also be during a driving operation of the motor vehicle 1 be carried out, in particular, the at least one actual pressure 11 is determined as an average, in particular during a predetermined and / or predefinable period of time.

According to a further alternative of the method is a for adjusting the reference level 21 in a reference loading condition and / or in the reference action 23 the spring device 19 for setting the reference level 21 by means of the actuator device 7 required hydraulic reference pressure provided, specified and / or determined. Advantageously, the reference pressure after loading with the then measured actual pressure 11 are compared, wherein from a corresponding difference and / or the comparison to the actual load state 15 of the motor vehicle 1 can be closed.

According to a further alternative of the method, an actively and / or passively generated disturbance, in particular a state of equilibrium of the motor vehicle 1 be generated and / or determined. In particular, an in 1 illustrated steering angle 25 of the motor vehicle 1 and a resulting steering size 27 be determined. Advantageously, an answer of the motor vehicle 1 on the steering angle 25 , So the disturbance, to be used to determine the actual load condition. Advantageously, during the response, the at least one actual pressure 11 be measured. In particular, a can for leveling the body 5 required actual pressure 11 , in particular on the outside wheels of the motor vehicle 1 to be used, the actual loading condition 15 to investigate.

According to a further preferred embodiment of the method, the equilibrium state of the motor vehicle 1 actively disturbed, in particular by means of an actuator of the active chassis 29 of the motor vehicle 1 , In particular, a transient response, in particular a frequency and / or amplitude of the body 5 be observed so as to the actual loading condition 15 zurückzuschließen. Alternatively or additionally, during the response to the active disturbance of the equilibrium state, corresponding parameters of the active chassis 29 be set. In particular, the suspension can 29 if the active disturbance of the equilibrium state at a standstill of the motor vehicle 1 takes place safely on "soft", making it particularly easy to set a frequency and / or amplitude of the body 5 can be measured. In particular, this can be the damper throttles 55 and 57 at the respective wheels 3 be opened and / or the pump generator 47 or the electric machine 49 be switched off or de-energized. In particular, a simple boarding of a person in the motor vehicle 1 be used as an active disturbance, so as early as a boarding of a user in the motor vehicle 1 on the actual loading condition 15 close.

Advantageously, control and / or control systems for influencing a lateral and / or longitudinal dynamics, in particular safety-related systems, in particular a vehicle dynamics control, in particular a float angle control, in particular driving assistants, in particular brake assist, Kollisionsfolgenminderungssysteme, slip control systems, anti-lock braking systems and / or the like with the aid of the recognized Ist -Beladungszustandes 15 adapted, parameterized and / or adjusted. In particular, a ride comfort of the motor vehicle 1 and / or a safety of the motor vehicle 1 be increased thereby.

The identification and / or the recognition of the actual loading condition 15 can during a drive of the motor vehicle 1 carried out and / or during a standstill, wherein the active disturbance can be used. Optionally, pitching and / or rolling movements in the body 5 of the motor vehicle 1 be embossed. In particular, this can be done rhythmically, in particular for the reproduction of a music. After disturbing the state of equilibrium and / or actively moving the body 5 can advantageously by means of the corresponding measurement of the actual pressure 11 on the actual loading condition 15 be closed back. Advantageously, corresponding additional systems can be parameterized accordingly.

At least one of the actual pressures becomes advantageous 11 directly by means of the corresponding pressure measuring device 13 measured. Alternatively or additionally, the voltage U _P and the current I _{P of} the electric machine 49 be used to determine one of the actual pressures. Advantageously, knowing the reference state 17 , which in particular also has the reference loading state, with the aid of the actual pressures 11 and / or the at least one actual pressure 11 on the actual loading condition 15 getting closed. In particular, a pressure difference can be formed, which is in knowledge of a transmission behavior of the actuator device 7 or the actuator devices 7 Conclusions about the actual load condition 15 allows.

Alternatively or additionally, further sensor signals 63 for detecting the actual loading condition 15 be used. For the other sensor signals 63 it may in particular be an actual acceleration, in particular an actual lateral acceleration and / or an actual longitudinal acceleration, an actual level of the motor vehicle 1 , a driving speed of the motor vehicle 1 , the steering angle 25 or the steering size 27 and / or act like that.

In the active suspension 29 of the motor vehicle 1 as in the 1 and 2 in particular, it is a part-carrying system, wherein the spring device 19 the bodywork 5 carries, per wheel 3 of the motor vehicle 1 a displacement control by means of the pump generator 47 is present, the pump generator 47 in the two gas storage 51 . 53 promotes.

Alternatively or additionally, however, is any kind of hydraulic activation, so any kind of active suspension 29 , suitable for carrying out the method described above.

LIST OF REFERENCE NUMBERS

1

motor vehicle

3

wheel

5

body

7

actuator device

9

It's on

11

Actual pressure

13

Pressure measuring device

15

Actual loading condition

17

reference state

19

spring device

21

reference level

23

reference effect

25

steering

27

steering variable

29

landing gear

31

hydraulic actuator

33

first optional step

35

second step

37

Third step

39

first working chamber

41

second working chamber

43

working piston

45

working cylinder

47

hydraulic pump generator

49

electric machine

51

first gas storage

53

second gas storage

55

first damper choke

57

second damper throttle

59

roof load

61

control device

63

sensor signal

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007047399 B4 [0002]
• DE 102010007237 A1 [0002]

Claims (10)

Method for detecting an actual state ( 9 ) of a motor vehicle ( 1 ), wherein the motor vehicle ( 1 ) one between a wheel ( 3 ) and a body ( 5 ) of the motor vehicle ( 1 ) acting hydraulic actuator device ( 7 ), comprising: determining an actual hydraulic state of the actuator device ( 7 ) describing the actual hydraulic variable, characterized by: measuring at least one in the actuator device ( 7 ) occurring hydraulic actual pressure ( 11 ) by means of one of the actuator device ( 7 ) hydraulically associated pressure measuring device ( 13 ) for determining the actual hydraulic variable, - detecting an actual load state ( 15 ) of the motor vehicle ( 1 ) as a function of the at least one hydraulic actual pressure ( 11 ) of the actuator device ( 7 ). Method according to the preceding claim, characterized by: providing a reference state ( 17 ) of the motor vehicle ( 1 ), - detecting the actual loading state ( 15 ) of the motor vehicle ( 1 ) additionally depending on the reference state ( 17 ). Method according to one of the preceding claims, characterized in that the motor vehicle ( 1 ) one between the wheel ( 3 ) and the body ( 5 ) parallel to the hydraulic actuator device ( 7 ) acting spring device ( 19 ), the reference state ( 17 ) a reference level ( 21 ) of the motor vehicle ( 1 ) and / or a reference effect ( 23 ) of the spring device ( 19 ), comprising: - setting and / or maintaining the reference level ( 21 ) by means of the actuator device ( 7 ) and / or the reference effect ( 23 ) of the spring device ( 19 ) after loading the motor vehicle ( 1 ), - measuring the actual hydraulic pressure ( 11 ) after loading to detect the actual loading state given after loading ( 15 ) of the motor vehicle ( 1 ). Method according to the preceding claim, characterized in that the reference state ( 17 ) has a reference loading state, comprising: providing, predetermining and / or determining one in the reference loading state and / or the reference effect ( 23 ) of the spring device ( 19 ) for setting the reference level ( 21 ) by means of the actuator device ( 7 ) required hydraulic reference pressure, - determining the actual load state of the motor vehicle ( 1 ) additionally depending on the hydraulic reference pressure. Method according to one of the preceding claims, characterized by: measuring the actual pressure ( 11 ) as a mean pressure during a driving operation of the motor vehicle ( 1 ). Method according to one of the preceding claims, characterized by: determining a steering angle ( 25 ) of the motor vehicle ( 1 ) descriptive steering quantity ( 27 ), - measuring the actual pressure ( 11 ) during a response of the motor vehicle ( 1 ) on the steering angle ( 25 ), - determining the actual loading state ( 15 ) in addition depending on the steering size ( 27 ) and the actual pressure measured during the response ( 11 ). Method according to one of the preceding claims, characterized by: - providing the motor vehicle ( 1 ) in an equilibrium state, - disturbing the equilibrium state, - measuring the actual pressure ( 11 ) during a response of the motor vehicle ( 1 ) on disturbing the state of equilibrium. Method according to the preceding claim, characterized by: - disturbing the state of equilibrium by means of an actuating element of the motor vehicle ( 1 ) selected from: the hydraulic actuator device ( 7 ), the actuator device ( 7 ) having active suspension ( 29 ) of the motor vehicle ( 1 ), a brake device, an engine management. Motor vehicle ( 1 ) with a wheel ( 3 ) having active suspension ( 29 ), per wheel ( 3 ) one between each wheel ( 3 ) and a body ( 5 ) of the motor vehicle ( 1 ) acting hydraulic actuator device ( 7 ) and a spring device ( 19 ), characterized in that at least one of the actuator devices ( 7 ) at least one pressure measuring device ( 13 ), by means of a in the actuator device ( 7 ) acting hydraulic actual pressure ( 11 ) is measurable, whereby depending on the actual pressure ( 11 ) an actual loading condition ( 15 ) of the motor vehicle ( 1 ) is recognizable. Motor vehicle ( 1 ), in particular according to the preceding claim 9, arranged, designed, constructed and / or equipped with software for carrying out a method according to one of the preceding claims 1-8.

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