DE102019125572A1 - Method for determining the pitch angle of a motor vehicle - Google Patents

Abstract

The invention relates to a method for determining the pitch angle (NW) of a motor vehicle (1), the following steps being carried out in the motor vehicle (1) during its operation: i) Determining a first level value (h1) of the motor vehicle (1) at a predetermined distance (a1) to the rear from the center of gravity (SP) of the motor vehicle (1) by means of sensor data from a first sensor system (2), the first level value (h1) indicating a deflection of the vehicle body in the direction perpendicular to the roadway (FB) at the predetermined first distance (a1) represents, wherein the first sensor system (2) comprises one or more environment sensors which, as sensor data for determining the first level value (h1), detect the vertical distance of their respective installation position to the roadway (FB) via radar radiation and / or ultrasonic waves; ii) determining a Information (IN) by means of sensor data from a second sensor system (5), the information (IN) converting a second level value (h2) of the motor vehicle (1) into a m predetermined second distance (a2) forward from the center of gravity (SP) of the motor vehicle (1) or on the information (IN) the second level value (h2) depends, the second level value (h2) a deflection of the vehicle body in the direction perpendicular to Represents the lane (FB) at the predetermined second distance (a2); iii) determining the pitch angle (NW) from the first altitude value (h1) and the information (IN).

Description

The invention relates to a method for determining the pitch angle of a motor vehicle and a corresponding motor vehicle.

It is known from the prior art to determine the pitch angle of a motor vehicle, which describes the inclination of the motor vehicle about its transverse axis relative to the roadway, using a plurality of height sensors installed at different longitudinal positions of the motor vehicle. These ride height sensors are usually inductive ride height sensors that use electromagnetic induction to record sensor data from which the ride height of the vehicle body results. A determined pitch angle is used, for example, for automatic headlight range adjustment of the headlights of the motor vehicle.

In order to reduce the number of inductive ride height sensors used when estimating the pitch angle, it is also known to determine the pitch angle only via a single inductive ride height sensor at a position in the rear area of the motor vehicle. For this it is necessary that further information is used to estimate the load distribution in the motor vehicle. For example, the seat belt lock contacts in the interior of the motor vehicle and possibly also a trailer signal are evaluated. The trailer signal indicates whether a trailer is attached to the motor vehicle. The number of seat belt buckle contacts (i.e. the closed belts) is used to determine the number of people in the interior and, depending on this, the deflection of the vehicle body in the front area of the motor vehicle is estimated, assuming standard personal weights. In this way, a ride height value of a virtual ride height sensor in the front area of the motor vehicle is obtained. The pitch angle is calculated from this ride height value in combination with the ride height value of the inductive ride height sensor in the rear area.

Inductive level sensors detect the relative movement of components to one another, so that they have to be installed on an axle of the motor vehicle to determine a level in order to detect the deflection of the vehicle body. As a result, the installation of inductive level sensors in a motor vehicle is complex and limited to certain installation positions.

The object of the invention is to create a method for determining the pitch angle of a motor vehicle with which the pitch angle is calculated using at least one ride height value that is obtained with a different sensor system than in the prior art.

This object is achieved by the method according to claim 1 or the motor vehicle according to claim 18. Developments of the invention are defined in the dependent claims.

The method according to the invention is used to determine the pitch angle of a motor vehicle. The motor vehicle is preferably a car, but it can also be a truck, for example. The pitch angle describes the inclination of the motor vehicle or the motor vehicle body about its transverse axis relative to the roadway. The transverse axis is the axis perpendicular to the longitudinal direction of the motor vehicle at the position of its center of gravity. In the context of the process according to the invention, steps i) to iii) described below are carried out. The numbering of these steps does not necessarily reflect the order in which they are carried out, unless one step requires the information of another step.

In step i) of the method according to the invention, a first level value of the motor vehicle is determined at a predetermined distance from the center of gravity of the motor vehicle by means of sensor data from a first sensor system. The specified first distance represents an offset in the longitudinal direction of the motor vehicle to the rear, starting from the center of gravity, and the first level value represents a deflection of the vehicle body in the direction perpendicular to the roadway at the specified first distance. Here and below, the concept of deflection of the vehicle body is used as a measure to understand for the vertical height position of the body of the motor vehicle. The deflection can be represented, for example, by the distance between the underside of the body and the roadway. Likewise, the deflection can be defined in relation to a predetermined zero position of the vehicle body, this zero position correlating with a specific distance between the underside of the vehicle body and the roadway.

The first sensor system comprises one or more environment sensors which are arranged in the longitudinal direction of the motor vehicle behind the center of gravity. The environmental sensor or sensors detect the vertical as sensor data for determining the first ride height value via radar radiation and / or ultrasonic waves Distance of their respective installation position to the roadway. In other words, a respective environment sensor is a radar sensor or an ultrasonic sensor. In this case, known radar sensors or ultrasonic sensors are used, which emit radar radiation or ultrasonic waves and detect radar radiation reflected from the roadway or ultrasonic waves reflected from the roadway, from which in a known manner and preferably via a transit time measurement the vertical distance of their respective installation position to Roadway can be determined. In a preferred variant, a single environment sensor is used, the vertical distance ascertained by this environment sensor correlating directly with a corresponding height value of the vehicle body. If necessary, several surroundings sensors can also be used, the vertical distances of which are appropriately offset against one another. For example, the mean value of the vertical distances can be calculated and the first altitude value can then be derived from this. In a preferred variant, the environment sensor (s) are positioned at the predetermined first distance, as a result of which the first level value can be derived particularly easily from the sensor data of the environment sensors.

In step ii) of the method according to the invention, information is determined by means of sensor data from a second sensor system. In one variant, the information ascertained is a second level value of the motor vehicle at a predetermined second distance from the center of gravity of the motor vehicle. Alternatively, however, the information can also be designed in such a way that it does not directly supply the second altitude value, but rather the second altitude value depends on the information, i.e. the second altitude value correlates with corresponding information. The predetermined second distance, for which the second ride height value is valid, represents an offset in the longitudinal direction of the motor vehicle forwards starting from the center of gravity, the second ride height value representing a deflection of the motor vehicle in the direction perpendicular to the roadway at the preset second distance. If necessary, a trailer signal can also be taken into account in step ii), which signal indicates whether a trailer is attached to the motor vehicle. This trailer signal also flows into the determination of the information in step ii).

Finally, in step iii) of the method according to the invention, the first altitude value determined in step i) and the information from step ii) are processed in order to determine the pitch angle therefrom.

The method according to the invention has the advantage that an environment sensor system is used to determine the pitch angle, which can detect a vertical distance by means of radar radiation and / or ultrasound waves independently of its installation position, from which a ride height value can be obtained. The environment sensor system does not require any mechanical relative movement of components to one another for level measurement, as is the case with inductive level sensors. The method according to the invention can thus be implemented in a simple manner in a motor vehicle.

In a preferred embodiment of the method according to the invention, the environment sensor or sensors of the first sensor system are arranged at the rear of the motor vehicle, which facilitates their installation in the motor vehicle. In a further preferred refinement, the environment sensor or sensors have a further function in addition to the function for level measurement. According to this further function, the environment sensor (s) can detect the penetration of a human foot into a detection area between the roadway and the underside of the vehicle body, with a door or flap of the motor vehicle being unlocked and / or opened when the penetration of a human foot is detected. The door or the flap is preferably above the detection area of the environment sensor or sensors and overlaps with the detection area in the vertical direction in a top view. In this embodiment, one or more environment sensors, which are already used for contactless opening or unlocking of doors or flaps by means of a foot movement, can also be used for level measurement. The method according to the invention can thus be implemented in a cost-effective manner. Here and in the following, the term door or flap is to be understood as a component with which an opening in the vehicle body can be covered. A door is preferably an entry door to the interior of the motor vehicle. A flap is preferably a trunk flap, but it can also represent a hood if necessary.

In a preferred variant of the embodiment just described, the detection area of the environment sensor (s) of the first sensor system is at the rear of the motor vehicle, with a trunk lid of the motor vehicle being unlocked and / or opened when the penetration of a human foot is detected.

The second sensor system used in the method according to the invention can be based on different technologies. In a variant, the second sensor system comprises one or more inductive level sensors known per se, which are arranged in the longitudinal direction of the motor vehicle in front of the center of gravity and in particular at a predetermined second distance and which detect sensor data via electromagnetic induction. In the event that the sensor data of the inductive level sensor or sensors are used in step ii), the second level value is determined as information in step ii) by means of the sensor data of the inductive level sensor or sensors. In a further preferred variant, only a single inductive ride height sensor is used to save costs. Nevertheless, several inductive level sensors can also be used if necessary whose sensor data are then appropriately offset against each other (eg averaging) in order to obtain the second altitude value.

In a further preferred embodiment, the second sensor system, analogous to the first sensor system, comprises one or more environment sensors, which, however, are now arranged in the longitudinal direction of the motor vehicle in front of the center of gravity and preferably at the predetermined second distance and, via radar radiation and / or ultrasonic waves, the vertical distance of their respective installation position to Capture the lane. In the event that the sensor data of the environment sensor (s) of the second sensor system are used in step ii), the second level value is determined as information in step ii) by means of the sensor data of the environment sensor (s) of the second sensor system. In a preferred variant, only a single environment sensor is provided for the second sensor system.

In analogy to the environment sensors of the first sensor system, the environment sensor (s) of the second sensor system can also be provided to detect the penetration of a human foot into a detection area of the environment sensor (s) of the second sensor system between the roadway and the underside of the vehicle body Penetration of a human foot a door or flap of the motor vehicle is unlocked and / or opened. The door or flap is in turn preferably above the detection area and overlaps with the detection area in a top view in the vertical direction. For example, the environment sensor (s) can be provided to trigger the unlocking or opening of the hood of the motor vehicle when the penetration of a human foot into a detection area of the environment sensor or sensors at the front of the motor vehicle is detected.

In a further embodiment, the second sensor system comprises a sensor device known per se for detecting the number of seatbelt lock contacts in the interior of the motor vehicle. This sensor device usually consists of individual sensors that are integrated in the individual belt buckles of the respective vehicle seats and provide the information as a sensor signal as to whether the respective belt buckle is closed, i.e. whether there is a seatbelt buckle contact or not. In the event that in step ii) the sensor data of the sensor device are used to detect the number of seatbelt lock contacts, occupant information is determined from the number of seatbelt lock contacts as information in step ii), which includes the number of occupants in the interior with their assigned seat positions.

In a further variant of the method according to the invention, the second sensor system comprises an imaging sensor device which detects the interior of the motor vehicle in order to obtain image data of the interior, in which case the sensor data of the imaging sensor device are used in step ii) as information in step ii) occupant information is determined by evaluating the image data using a method for object recognition, the occupant information including the number of occupants in the interior with their assigned seating positions. In a preferred variant, the image data obtained with the imaging sensor device are three-dimensional image data. In other words, the imaging sensor device is designed to capture three-dimensional spatial information.

With the embodiment just described, the occupant detection can be improved compared to the use of a sensor system to detect the number of seatbelt buckle contacts and in particular the case can no longer arise that people are not detected who do not buckle up in the motor vehicle, or incorrectly via a Belt secured object is recognized as a person.

Depending on the configuration, different imaging sensor devices can be used to detect the interior of the motor vehicle. In a preferred embodiment, the imaging sensor device comprises one or more cameras for visible light and / or infrared light and / or one or more radar sensors which generate image information by measuring the transit time. The camera or cameras are preferably designed in such a way that they definitely capture image data based on infrared light, so that the number of occupants in the interior of the motor vehicle can be accurately detected even in the dark.

In a further, particularly preferred embodiment, the occupant information, which is determined by means of the sensor data of the imaging sensor device, further comprises one or more features of each occupant, which are obtained from the image data of the imaging sensor device. Thus, the calculation of the pitch angle also takes place as a function of the feature (s) of the occupant (s). In a preferred variant, the estimated weight of each occupant is determined as a feature. The term estimated weight is to be understood broadly. In particular, the estimated weight can be represented by a weight class or a weight interval. The estimated weights can be used in a suitable manner in the estimation of the pitch angle, with the precise implementation taking into account these weights are within the scope of professional action. In particular, this implementation takes into account the fact that higher weights of people lead to a low second level value in the front area of the motor vehicle.

In a particularly preferred variant of the above embodiment, the estimated weight of each occupant is determined by using the image data to determine the gender and / or size of the respective occupant and / or the volume or area which a respective occupant occupies in the image data , is extracted, and based on this extracted information, the weight of the respective occupant is estimated. In this embodiment, the knowledge is used that the size of a respective occupant or his volume or his area have an influence on his weight, wherein the influence can also depend on the gender (i.e. male or female) of the person. In the context of the weight estimation, the information about the seating position of the occupants can also be used, if necessary. For example, the weight of two occupants with the same occupied volume is estimated to be higher by that occupant who is in a seating position further back in the motor vehicle.

In a further embodiment of the method according to the invention, which uses sensor data from a sensor device to detect the number of seatbelt lock contacts or from an imaging sensor device, a lookup table with a large number of specified occupant information and specified first height values is used to determine the pitch angle -Table, an entry in the form of a pitch angle or a value dependent thereon is stored for each combination of specified occupant information and specified first altitude value, the entry being read from the lookup table which corresponds to the combination of the first altitude value determined by the first sensor system and corresponds to the occupant information determined in step ii). This enables the pitch angle to be determined quickly. In the event that the read entry in the lookup table represents the pitch angle itself, the read pitch angle corresponds to the determined pitch angle.

In a variant of the embodiment just described, the entries in the lookup table are predetermined second ride height values, so that the second ride height value of the motor vehicle, i.e. the ride height value defined in step ii), is read from the lookup table. The pitch angle is determined from the first altitude value and the second altitude value. This determination can take place in that the difference between the first and second height value is formed and this difference is divided by the distance between the position of the predetermined first distance and the position of the predetermined second distance.

Depending on the configuration, the determined pitch angle can be used for different functions in the motor vehicle. One or more lighting devices in the motor vehicle are preferably controlled as a function of the determined pitch angle. In particular, this control is an automatic headlight range adjustment of the headlights of the motor vehicle.

1. i) Bestimmen eines ersten Höhenstandwerts des Kraftfahrzeugs in einem vorgegebenen ersten Abstand vom Schwerpunkt des Kraftfahrzeugs mittels Sensordaten des oder der Umfeldsensoren der ersten Sensorik, wobei der vorgegebene erste Abstand einen Versatz in Längsrichtung des Kraftfahrzeugs nach hinten ausgehend vom Schwerpunkt repräsentiert und der erste Höhenstandswert eine Auslenkung der Fahrzeugkarosserie in Richtung senkrecht zur Fahrbahn im vorgegebenen ersten Abstand darstellt,
2. ii) Ermitteln einer Information mittels Sensordaten der zweiten Sensorik, wobei die Information ein zweiter Höhenstandwert des Kraftfahrzeugs in einem vorgegebenen zweiten Abstand vom Schwerpunkt des Kraftfahrzeugs ist oder von der Information der zweite Höhenstandswert abhängt, wobei der vorgegebene zweite Abstand einen Versatz in Längsrichtung des Kraftfahrzeugs nach vorne ausgehend vom Schwerpunkt repräsentiert und der zweite Höhenstandswert eine Auslenkung der Fahrzeugkarosserie in Richtung senkrecht zur Fahrbahn im vorgegebenen zweiten Abstand darstellt;
3. iii) Ermitteln des Nickwinkels aus dem ersten Höhenstandswert und der in Schritt ii) ermittelten Information.

In addition to the method described above, the invention relates to a motor vehicle that is set up to determine its pitch angle, the pitch angle describing the inclination of the motor vehicle about its transverse axis relative to the roadway. The motor vehicle is configured to carry out the method according to the invention. In other words, the motor vehicle comprises a first sensor system and a second sensor system, the first sensor system including one or more environment sensors which are arranged in the longitudinal direction of the motor vehicle behind the center of gravity of the motor vehicle and are set up to receive, as sensor data, the vertical distance of their respective installation position to Detecting the lane using radar radiation and / or ultrasonic waves, the motor vehicle also containing a computer device which is configured to carry out the following steps:

1. i) Determination of a first level value of the motor vehicle at a predetermined first distance from the center of gravity of the motor vehicle using sensor data from the environment sensor (s) of the first sensor system, the predetermined first distance representing an offset in the longitudinal direction of the motor vehicle to the rear starting from the center of gravity and the first level value representing a deflection of the Represents the vehicle body in the direction perpendicular to the roadway at the specified first distance,
2. ii) Determining information by means of sensor data from the second sensor system, the information being a second level value of the motor vehicle at a predetermined second distance from the center of gravity of the motor vehicle or the second level value depending on the information, the predetermined second distance being an offset in the longitudinal direction of the motor vehicle represents the front starting from the center of gravity and the second level value represents a deflection of the vehicle body in the direction perpendicular to the roadway at the predetermined second distance;
3. iii) determining the pitch angle from the first altitude value and the information determined in step ii).

The computer device of the motor vehicle according to the invention can optionally be distributed among various components in the motor vehicle. In particular, functionalities of the computer device can also be implemented at least partially in the corresponding first or second sensor system.

In a particularly preferred embodiment, the motor vehicle according to the invention is set up to carry out one or more preferred variants of the method according to the invention.

An exemplary embodiment of the invention is described in detail below with reference to the accompanying figures.

• 1 eine schematische Darstellung eines Kraftfahrzeugs, das zur Schätzung seines Nickwinkels basierend auf einer Variante des erfindungsgemäßen Verfahrens eingerichtet ist; und
• 2 ein Flussdiagramm, welches das im Kraftfahrzeug der 1 verwendete Verfahren zur Schätzung des Nickwinkels wiedergibt.

Show it:

• 1 a schematic representation of a motor vehicle that is set up to estimate its pitch angle based on a variant of the method according to the invention; and
• 2 a flowchart showing the in the motor vehicle of 1 represents the method used to estimate the pitch angle.

A variant of the method according to the invention is described below using a motor vehicle in the form of a passenger car 1 described. The motor vehicle is in 1 shown in side view and is located on a horizontal roadway FB . The motor vehicle includes a rear axle 3rd and a front axle 3 ' .

At the rear of the motor vehicle 1 there is a radar sensor 2 , the radar radiation in a detection area EB down to the lane FB sends out. The detection range of the radar sensor extends in the transverse direction of the motor vehicle essentially along the entire rear. In a manner known per se, the radar sensor detects the radar echo of the radar radiation it emits via one or more receiving antennas and determines the distance between the underside of the motor vehicle body and the lane from the radar echo (ie from the radar radiation reflected back from the roadway) FB . This distance becomes the computing device described in more detail below 6th provided, which from this a first level value h1 (please refer 2 ), which determines the vertical deflection of the vehicle body relative to the rear axle 3rd at the location of the radar sensor 2 describes in relation to a zero position. In other words, it becomes the first level value h1 at a distance a1 from the center of gravity SP of the motor vehicle determined. Instead of the radar sensor 2 An ultrasonic sensor can also be used, which uses the echo of transmitted ultrasonic waves to determine the distance between the underside of the motor vehicle body and the roadway FB determined.

The car 1 also contains an imaging sensor device in the form of a 3D camera 5, which is located in the interior 4th of the motor vehicle is provided. This camera 5 represents an embodiment of a second sensor system within the meaning of claim 1. Instead of a camera, an inductive level sensor, a sensor device for determining the number of seatbelt lock contacts or possibly a further radar sensor or an ultrasonic sensor can also be used as the second sensor system. Using the sensor data from the second sensor system, a second ride height value is obtained h2 (please refer 2 ) at the location of the front axle 3 ' of the motor vehicle 1 derived. The front axle shows the distance a2 from the center of gravity SP of the motor vehicle. The second level value h2 corresponds to the vertical deflection of the vehicle body in relation to the front axle 3 ' in relation to a zero position.

The camera 5 of the motor vehicle of the 1 serves to detect light in the visible range as well as in the infrared range. The computer device uses the three-dimensional image data from the camera 6th an occupant information IN (please refer 2 ) determines which, among other things, the number of occupants in the interior of the motor vehicle 1 includes. In the scenario of the 1 there is a single occupant in the form of a human person P in the driver's seat. From the occupant information IN then becomes the second level value h2 obtained by means of the computing device 6th with the first altitude value h1 is offset to thereby the pitch angle NW to determine the motor vehicle, as will be described in more detail below. The pitch angle NW will focus on SP of the motor vehicle and describes the tilting of the motor vehicle body around the transverse axis of the motor vehicle located at the center of gravity. The transverse axis runs perpendicular to the longitudinal direction LR of the motor vehicle. This longitudinal direction is in 1 indicated by an arrow, the direction of the arrow being the forward direction of travel of the motor vehicle 1 corresponds to.

The pitch angle NW is used in the embodiment described here in a manner known per se for automatic headlight range control of the headlights 7th of the motor vehicle in order to avoid dazzling oncoming traffic. In other words, the Headlight range adjustment the position of the headlights 7th depending on the pitch angle NW always in such a way that oncoming traffic is not blinded. This means that the greater the pitch angle, the more the headlights are tilted downwards.

In contrast to conventional methods for determining the pitch angle, in the embodiment described here, the pitch angle is determined using a first altitude value h1 determined with the radar sensor described above 2 was recorded. In addition to the function of measuring the distance between the body and the roadway, this radar sensor also has the function of detecting the penetration of a human foot into the detection area EB of the radar sensor. If such an intrusion is detected, the trunk lid of the motor vehicle opens automatically. The radar sensor 2 thus has a double function in the motor vehicle. In other words, a radar sensor already installed in the motor vehicle, which originally serves to open the trunk lid without contact, can also be used as a level sensor.

2 shows a flow chart in which the determination of the pitch angle NW in the motor vehicle of the 1 shown in detail. In a step S1, the first level value is first h1 at a distance a1 from the center of gravity SP by means of the sensor data of the radar sensor 2 certainly. In a step S2, the interior 4th of the motor vehicle by means of the camera 5 captured, creating corresponding image data BD can be obtained from the interior. This image data BD are in step S3 by the computer device 6th evaluated. The occupant information IN determines which at least the number N the people in the vehicle and their seating positions PO includes. The seat positions are specified on the basis of a classification which indicates whether the respective persons are in the driver or front passenger seat or in the rear.

To determine the occupant information IN is in the computing device 6th an algorithm known per se is used for object recognition, which is based on an analysis of the image data BD recognizes how many occupants there are in the motor vehicle or what seat positions they are in. In one variant, only the information is given with regard to the number N the occupants and their seating positions PO used to determine the second level value in a next step S4 h2 to determine.

To determine the second ride height value h2 is in the computing device 6th a lookup table is stored in the for a large number of combinations of possible first altitude values of the radar sensor 2 and possible occupant information (ie the respective information about how many occupants are seated in which seat positions), corresponding second level values are stored, which level values of a virtual level sensor on the front axle 3 ' represent. The ride height value is thus obtained with this lookup table h2 a virtual ride height sensor on the front axle 3 ' simulated. Used as occupant information IN For example, it is determined that only the driver is in the motor vehicle, the level value is h2 of the virtual ride height sensor (ie the corresponding deflection on the front axle 3 ' ) is assumed to be greater than in the case where there is also a passenger in the vehicle in addition to the driver.

The second ride height value is obtained from the lookup table in step S4 h2 depending on the current occupant information IN and the current first level value h1 of the radar sensor 2 read out. Then in step S5 by means of the computer device 6th the pitch angle NW based on the difference between the two ride height values h1 and h2 and knowing the distance between the front axle 3 ' and the radar sensor 2 (Sum of distances a1 and a2 ) determined. In a modified embodiment, a corresponding pitch angle is stored directly in the lookup table, so that it no longer has to be calculated in a separate calculation step and to a determination of the second altitude value h2 can be dispensed with.

Instead of using a lookup table, it may also be possible to define a suitable functional relationship via which the pitch angle NW from the occupant information IN in combination with the first altitude value h1 of the radar sensor 2 is calculated. The determination of a suitable function lies within the scope of professional action.

In a modified embodiment of the method of 2 is used as occupant information IN in step S3 next to the number N of occupants and their seating positions PO also the respective weight G of the individual inmates appreciated. The weights are given in the form of weight classes that define different weight intervals. The estimation of the weights can be carried out with the aid of the algorithm for object recognition. For example, this can be done with the camera 5 recorded volumes of the corresponding persons are extracted from the image data and a weight or a weight class of the respective person is estimated based thereon, taking into account the sitting position. The algorithm for object recognition preferably also supplies the gender of the respective occupant, which in turn has an influence on how high the corresponding weight is as a function of the recorded volume of the respective person.

The estimated weights can be included as a further variable in the lookup table described above by using them as further parameters of the occupant information IN must be taken into account. In other words, occupant information specifies not only the number of occupants and their seating positions, but also their weights. This results in a larger number of possible occupant information items and thus a larger number of table entries.

The in step S5 of the 2 obtained information of the pitch angle NW can then be used for various purposes in the motor vehicle. In the embodiment described here, the information about the pitch angle NW for headlight range adjustment 7th used as described above. Nonetheless, the estimated pitch angle can also be used, for example, when projecting display elements into the driver's field of vision, provided the position of the display elements depend on the pitch angle. This is the case when the display elements are overlaid with certain real elements in the vehicle environment.

The embodiments of the invention described above have a number of advantages. In particular, a radar sensor system and / or an ultrasonic sensor system is used for the first time to determine a ride height value in a motor vehicle in order to use this in combination with a further sensor system to determine the pitch angle of a motor vehicle. The radar sensor system or the ultrasonic sensor system has the advantage that, in contrast to inductive level sensors, it can be installed at different positions in the motor vehicle in order to obtain a level value via a distance measurement. In the method according to the invention, the use of inductive level sensors can optionally be completely dispensed with. This can be achieved in that the above-described second ride height value is determined by means of sensor data from a camera or possibly by means of a further radar and / or ultrasonic sensor system or also a sensor system for detecting the number of seatbelt lock contacts.

List of reference symbols

1

Motor vehicle

2

Radar sensor

3

Rear axle

3 '

Front axle

4th

inner space

5

camera

6th

Computing facility

7th

Front headlights

FB

roadway

SP

Focus on the motor vehicle

NW

Pitch angle

a1

Distance between the radar sensor and the center of gravity

a2

Distance between the front axle and the center of gravity

LR

Longitudinal direction of the motor vehicle

P

inmate

h1

first level value

h2

second level value

BD

Image data

IN

Occupant information

N

Number of occupants

PO

Sitting position of the respective occupants

G

Weight of the respective occupants

Claims (19)

Method for determining the pitch angle (NW) of a motor vehicle (1), which describes the inclination of the motor vehicle (1) about its transverse axis relative to the roadway (FB), the following steps being carried out in the motor vehicle (1) during its operation: i) Determination a first level value (h1) of the motor vehicle (1) at a predetermined first distance (a1) from the center of gravity (SP) of the motor vehicle (1) by means of sensor data from a first sensor system (2), the predetermined first distance (a1) being an offset in the longitudinal direction (LR) of the motor vehicle (1) to the rear starting from the center of gravity (SP) and the first level value (h1) represents a deflection of the vehicle body in the direction perpendicular to the roadway (FB) at the specified first distance (a1), the first sensor system ( 2) comprises one or more environment sensors which are arranged in the longitudinal direction (LR) of the motor vehicle (1) behind the center of gravity (SP) and as sensor data for determining the first ride height swerts (h1) detect the vertical distance of their respective installation position to the roadway (FB) via radar radiation and / or ultrasonic waves; ii) Determining information (IN) by means of sensor data from a second sensor system (5), the information (IN) being a second level value (h2) of the motor vehicle (1) at a predetermined second distance (a2) from the center of gravity (SP) of the motor vehicle (1) or the second level value (h2) depends on the information (IN), the predefined second distance (a2) representing an offset in the longitudinal direction (LR) of the motor vehicle (1) to the front starting from the center of gravity (SP) and the second level value (h2) represents a deflection of the vehicle body in the direction perpendicular to the roadway (FB) at the predetermined second distance (a2); iii) determining the pitch angle (NW) from the first altitude value (h1) and the information (IN). Procedure according to Claim 1 , characterized in that the environment sensor or sensors of the first sensor system (2) are arranged at the rear of the motor vehicle (1). Procedure according to Claim 1 or 2 , characterized in that the environment sensor or sensors of the first sensor system (2) are also provided to prevent a human foot from penetrating a detection area (EB) of the environment sensor or sensors of the first sensor system (2) between the roadway (FB) and the underside of the vehicle body to detect, with the detection of the penetration of a human foot a door or flap of the motor vehicle (1), which is preferably above the detection area (EB) and overlaps in a top view in the vertical direction with the detection area (EB), unlocked and / or opened becomes. Procedure according to Claim 3 , characterized in that the detection area (EB) of the environment sensor (s) of the first sensor system (2) is at the rear of the motor vehicle (1), with a trunk lid of the motor vehicle being unlocked and / or opened when the penetration of a human foot is detected. Method according to one of the preceding claims, characterized in that the second sensor system (5) comprises one or more inductive level sensors, which are arranged in the longitudinal direction (LR) of the motor vehicle (1) in front of the center of gravity (SP) and detect sensor data via electromagnetic induction, in the event that the sensor data of the inductive level sensor or sensors are used in step ii), the second level value (h2) is determined as information (IN) in step ii) by means of the sensor data of the inductive level sensor or sensors. Method according to one of the preceding claims, characterized in that the second sensor system (5) comprises one or more environment sensors which are arranged in the longitudinal direction (LR) of the motor vehicle (1) in front of the center of gravity (SP) and which use radar radiation and / or ultrasonic waves Detect vertical distance of their respective installation position to the roadway (FB), in the event that the sensor data of the environment sensor or sensors of the second sensor system (5) are used in step ii), the second level value (h2) as information (IN) in step ii) ) is determined by means of the sensor data of the environment sensor or sensors of the second sensor system (5). Procedure according to Claim 6 , characterized in that the environment sensor (s) of the second sensor system (5) are also provided to detect the penetration of a human foot into a detection area of the environment sensor (s) of the second sensor system (5) between the roadway (FB) and the underside of the vehicle body, wherein when the penetration of a human foot is detected, a door or flap of the motor vehicle, which is preferably above the detection area (EB) and overlaps with the detection area in the vertical direction, is unlocked and / or opened. Method according to one of the preceding claims, characterized in that the second sensor system (5) comprises a sensor device for detecting the number of seatbelt lock contacts in the interior (4) of the motor vehicle (1), wherein in the event that in step ii) the sensor data of the sensor device can be used to detect the number of seatbelt lock contacts, as information (IN) in step ii) from the number of seatbelt buckle contacts an occupant information is determined, which the number (N) of occupants (P) in the interior (4) with their assigned seat positions (PO ) includes. The method according to any one of the preceding claims, characterized in that the second sensor system (5) comprises an imaging sensor device which detects the interior (4) of the motor vehicle (1) in order to obtain image data (BD) of the interior (4), wherein im In the event that the sensor data of the imaging sensor device are used in step ii), occupant information is determined as information (IN) in step ii) by evaluating the image data (BD) using a method for object recognition, the occupant information being the number (N) of Includes occupants (P) in the interior (4) with their assigned seating positions (PO). Procedure according to Claim 9 , characterized in that the imaging sensor device (5) comprises one or more cameras for visible light and / or infrared light and / or one or more radar sensors. Procedure according to Claim 9 or 10 characterized in that the occupant information further comprises one or more features of each occupant (P) which are determined from the image data (BD) of the imaging sensor device. Procedure according to Claim 11 , characterized in that one feature is the estimated weight (G) of each occupant (P). Procedure according to Claim 12 , characterized in that the estimated weight (G) of each occupant (P) is determined by using the image data (BD) to determine the gender and / or the size of the respective occupant (P) and / or the volume or the area which or which a respective occupant (P) occupies in the image data (BD) is extracted and based on this extracted information the weight (G) of the respective occupant (P) is estimated. Method according to one of the Claims 8 to 13th , characterized in that a lookup table is used to determine the pitch angle (NW) with a large number of predetermined occupant information and predetermined first altitude values, an entry in the form in the lookup table for each combination of predefined occupant information and predefined first altitude value a pitch angle (NW) or a value dependent on it is stored, the entry being read from the lookup table which corresponds to the combination of the first altitude value (h1) determined by the first sensor system (2) and that determined in step ii) Occupant information (IN) corresponds. Procedure according to Claim 14 , characterized in that the entries in the lookup table are predetermined second ride height values, so that the second ride height value (h2) of the motor vehicle (1) is read from the lookup table, the first ride height value (h1) and the second ride height value ( h2) the pitch angle (NW) is calculated. Method according to one of the preceding claims, characterized in that one or more lighting devices (7) in the motor vehicle (1) are controlled as a function of the determined pitch angle (NW). Procedure according to Claim 16 , characterized in that the control comprises an automatic headlight range control of the headlights of the motor vehicle (1). Motor vehicle that is set up to determine its pitch angle (NW), the pitch angle (NW) describing the inclination of the motor vehicle (1) about its transverse axis relative to the roadway (FB), the motor vehicle (1) having a first sensor system (2) and a second sensor system (5), the first sensor system (2) comprising one or more environment sensors which are arranged in the longitudinal direction (LR) of the motor vehicle (1) behind the center of gravity (SP) of the motor vehicle (1) and are set up to to detect the vertical distance of their respective installation position to the roadway (FB) via radar radiation and / or ultrasonic waves as sensor data, the motor vehicle also containing a computer device (6) which is configured to carry out the following steps: i) Determination of a first level value (h1) of the motor vehicle (1) at a predefined first distance (a1) from the center of gravity (SP) of the motor vehicle (1) by means of sensor data from the environment sensor or sensors of the first sensor system (2), the predefined first distance (a1) represents an offset in the longitudinal direction (LR) of the motor vehicle (1) to the rear starting from the center of gravity (SP) and the first level value (h1) represents a deflection of the vehicle body in the direction perpendicular to the roadway (FB) at the specified first distance (a1) represents ii) determining information (IN) by means of sensor data from the second sensor system (5), the information (IN) being a second level value (h2) of the motor vehicle (1) at a predetermined second distance (a2) from the center of gravity (SP) of the motor vehicle ( 1) or the second level value (h2) depends on the information (IN), the predefined second distance (a2) representing an offset in the longitudinal direction (LR) of the motor vehicle (1) to the front starting from the center of gravity (SP) and the second Height level value (h2) represents a deflection of the vehicle body in the direction perpendicular to the roadway (FB) at the predetermined second distance (a2); iii) determining the pitch angle (NW) from the first altitude value (h1) and the information (IN). Motor vehicle after Claim 18 , characterized in that the motor vehicle for performing a method according to one of the Claims 2 to 17th is set up.

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