DE102024101164A1 - Method for operating a motor vehicle, motor vehicle and computer program product - Google Patents

Abstract

The invention relates to a method for operating a motor vehicle (2) which has a sensor device (6, 8) and a data processing device (10), wherein basic data are generated by means of a primary sensor unit (6) of the sensor device (6, 8), which map a force acting on a seat surface (18) of a vehicle seat (4) due to a weight of a vehicle occupant (12), wherein auxiliary data are generated by means of a secondary sensor unit (8) of the sensor device (6, 8), which map a deviation of a seat position of the vehicle occupant (12) from a predetermined standard seat position, and wherein, in a basic operating mode of the motor vehicle (2), the basic data are mapped by means of the data processing device (10) based on the auxiliary data to standard data which map a force acting on the seat surface (18) of the vehicle seat (4) due to the weight of the vehicle occupant (12) in the predetermined standard seat position.

Description

The invention relates to a method for operating a motor vehicle. Furthermore, the invention relates to a motor vehicle and a computer program product.

In the automotive sector, simple systems for detecting seat occupancy are known.

Furthermore, systems are known that enable a more precise weight determination. If a motor vehicle is equipped with such a system for more precise weight determination, it typically has at least one vehicle seat in which at least one sensor or at least one sensor unit is integrated, with which the body weight of a vehicle occupant can be determined or at least assigned to a weight class. Such a system is described, for example, in US 2022/021957 A1 described.

The information obtained in this way is then typically used to make a weight-specific adjustment to at least one other system of the motor vehicle, such as a belt tensioner system or an airbag system.

Depending on their design, systems for more specific weight determination use force sensors integrated into bolts on a base structure of the vehicle seat. Systems with this design have the problem that they can be compromised by a foreign object, such as a water bottle that gets under the vehicle seat.

In other embodiments, at least one sensor unit is integrated into a seat cushion of the vehicle seat below a seat surface. The sensor unit is designed, for example, as a capacitive sensor unit or, for example, as a so-called "bladder mat," in which pressure measurements are taken in several separate volumes during operation. The problem with such embodiments is that the accuracy of the measurement depends on the seating position of the vehicle occupant. As long as the vehicle occupant is in a predetermined standard seating position, a relatively high level of measurement accuracy can typically be achieved. However, the further the seating position deviates from the standard seating position, the lower the measurement accuracy becomes.

This problem is particularly important for vehicles designed for at least partially autonomous driving, as this offers all vehicle occupants the opportunity to move more freely within the vehicle interior.

The object of the present invention is to provide an advantageous method for operating a motor vehicle. Furthermore, the object of the present invention is to provide an advantageously configured motor vehicle and an advantageous computer program product.

This object is achieved by a method having the features of patent claim 1, by a motor vehicle having the features of patent claim 9, and by a computer program product having the features of patent claim 10. The advantages and preferred embodiments cited with regard to the method are also transferable mutatis mutandis to the devices, i.e., the computer program product on the one hand and the motor vehicle on the other, and vice versa. Advantageous embodiments with expedient further developments of the invention are specified in the dependent patent claims.

The method according to the invention is intended for execution in the motor vehicle according to the invention or by the motor vehicle according to the invention and is designed accordingly. Conversely, the motor vehicle according to the invention is configured to execute the method according to the invention in at least one operating mode.

The motor vehicle, i.e., the motor vehicle according to the invention, has a sensor device and a data processing device. The sensor device includes a primary sensor unit and a secondary sensor unit, each of which is connected to the data processing device via signaling.

During the execution of the method, i.e., the method according to the invention, basic data is generated by the primary sensor unit and expediently transmitted to the data processing device. This basic data represents a force acting on a seat surface of a vehicle seat caused by the weight of a vehicle occupant sitting on the vehicle seat. Furthermore, during the execution of the method, auxiliary data is generated by the secondary sensor unit and expediently transmitted to the data processing device. The auxiliary data represents a deviation of the vehicle occupant's seating position from a predetermined standard seating position.

The data generated in this way are further processed in a basic operating mode of the motor vehicle by means of the data processing device, whereby the basic data are mapped on the basis of the auxiliary data to standard data which depict a force acting on the seat surface of the vehicle seat by the weight of the vehicle occupant in the specified standard seating position.

The concept underlying the process can be simplified as follows: The primary sensor unit takes a measurement to determine the weight of the vehicle occupant. The secondary sensor unit simultaneously determines the current seating position of the vehicle occupant, allowing it to be deduced how much the current seating position of the vehicle occupant distorts the measurement taken. Based on this information, the data processing unit then determines the weight of the vehicle occupant by converting the measured weight into a calculated or computed weight. The calculated weight corresponds to the weight that would also be measured if the vehicle occupant were in a seating position that corresponds to the specified standard seating position.

Depending on the application, the primary sensor unit is embodied, for example, by a capacitive sensor unit or by a so-called "bladder mat" as mentioned above. The primary sensor unit is expediently integrated below a seat surface into a seat cushion of a seat base of the vehicle seat. The vehicle seat typically also has a seat back. Preferably, no sensor unit is integrated into this, at least not a sensor unit for detecting the application of force.

The secondary sensor unit preferably has at least one camera, so that the auxiliary data is generated by the at least one camera. Typically, image data is generated by the at least one camera, and this image data is then evaluated in the data processing device using image recognition.

According to an alternative embodiment, the secondary sensor unit is designed to only measure the inclination of a seat back of the vehicle seat.

Preferably, a weight classification for the vehicle occupant is further determined based on the standard data. In the simplest case, two weight classes are specified, for example, an "adult" weight class and a "child" weight class.

It is also advantageous if, on the basis of the standard data or on the basis of the weight classification determined for the vehicle occupant, a weight-specific adjustment is made to at least one other system of the motor vehicle, such as a belt tensioner system or an airbag system.

Independently of this, a preferred method variant is one in which the auxiliary data is subjected to a plausibility check. In this case, the motor vehicle preferably switches from the aforementioned basic operating mode to a first auxiliary operating mode if the auxiliary data is assessed as implausible during the plausibility check. As soon as the auxiliary data is again assessed as plausible during the plausibility check, the motor vehicle expediently switches back from the first auxiliary operating mode to the basic operating mode. In the first auxiliary operating mode, the basic data is determined as standard data by the data processing device.

In the simplified concept description presented above, this means that in the first auxiliary operating mode, the measured weight is not converted because it is simply assumed that the current sitting position corresponds to the standard sitting position, even if the actual sitting position is actually not known.

If the secondary sensor unit now has the camera, the auxiliary data is assessed as implausible, for example, if the image recognition detects a fogged and/or dirty lens.

According to at least one variant of the method, the basic data is also subjected to a plausibility check. The motor vehicle then switches from the basic operating mode to a second auxiliary operating mode if the basic data is assessed as implausible during the plausibility check. As soon as the basic data is again assessed as plausible during the plausibility check, the motor vehicle expediently switches back from the second auxiliary operating mode to the basic operating mode. In the second auxiliary operating mode, the data processing device determines the standard data without the basic data based on the auxiliary data.

In the simplified concept description presented above, this means that a weight is determined without measurement data from the primary sensor unit.

If the secondary sensor unit now includes a camera, the basic data is assessed as implausible, for example, if the image recognition determines that the vehicle occupant's pelvis is outside a specified zone. If the basic data is assessed as implausible, the weight of the vehicle occupant is determined, for example, based solely on image analysis.

Depending on the application, the base data is further mapped to the standard data in basic operating mode using a selected mathematical function. Thus, a correction function is predefined and stored in the data processing device.

According to an alternative embodiment, the base data is mapped to the standard data using a mapping rule created by machine learning.

As already mentioned, the method according to the invention described above is intended for execution in the motor vehicle according to the invention or by the motor vehicle according to the invention and is designed accordingly for this purpose. Conversely, the motor vehicle according to the invention is set up to execute the corresponding method in at least one operating mode. It has the sensor device described above and the data processing device described above. The data processing device is then expediently used to execute the individual method steps of the method or at least the execution of a number of method steps of the method, wherein for this purpose an executable program is typically stored or installed in the data processing device which, after startup, automatically executes the method or the number of method steps of the method.

A corresponding program can also be subsequently installed or stored using a computer program product according to the invention, provided that a suitable sensor device and a suitable data processing device are already present in a motor vehicle. This computer program product is typically a file or a data storage device containing a file, wherein the file contains the executable program, i.e., in particular, a suitable program code.

It should be pointed out again that the advantages and preferred embodiments mentioned with regard to the method are also to be transferred mutatis mutandis to the devices, i.e. the computer program product on the one hand and the motor vehicle on the other hand, and vice versa.

• 1 in einer Seitenansicht ein Kraftfahrzeug mit einem Fahrzeugsitz;
• 2 in einer Blockschaltbilddarstellung das Kraftfahrzeug;
• 3 in einer Seitenansicht der Fahrzeugsitz in einer ersten Einstellung zusammen mit einem Insassen in einer ersten Sitzposition;
• 4 in einer Seitenansicht der Fahrzeugsitz in einer zweiten Einstellung zusammen mit dem Insassen in einer zweiten Sitzposition;
• 5 in einem Kräftediagramm mehrere in der zweiten Sitzposition wirkende Kräfte;
• 6 in einem Diagramm ein Skalierungsfaktor in Abhängigkeit eines ersten Winkels;
• 7 in einem Diagramm der Skalierungsfaktor in Abhängigkeit eines zweiten Winkels; und
• 8 in einem Diagramm ein gemessenes Signal sowie ein ermitteltes Signal.

Further advantages, features, and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the schematic drawings. These show:

• 1 in a side view a motor vehicle with a vehicle seat;
• 2 in a block diagram representation of the motor vehicle;
• 3 in a side view of the vehicle seat in a first setting together with an occupant in a first seating position;
• 4 in a side view, the vehicle seat in a second setting together with the occupant in a second seating position;
• 5 in a force diagram several forces acting in the second seating position;
• 6 in a diagram, a scaling factor depending on a first angle;
• 7 in a diagram the scaling factor as a function of a second angle; and
• 8 in a diagram a measured signal and a determined signal.

Corresponding parts are provided with the same reference numerals in all figures.

In 1 A motor vehicle 2 is shown in a highly simplified side view. It has four vehicle seats 4, namely a driver's seat, a passenger seat, and two rear seats. In the exemplary embodiment, the vehicle seats 4 are designed as individual seats and each have a sensor mat 6, which is formed, for example, by a so-called "bladder mat." 3 and 4 one of the vehicle seats 4 is sketched as an example.

The sensor mat 6 of the vehicle seat 4 according to 3 and 4 In the exemplary embodiment, it forms a primary sensor unit of a sensor device of the motor vehicle 2. This sensor device also comprises a secondary sensor unit, which is exemplified by a camera 8. Sensor mat 6 and camera 8 are connected by signaling to a data processing device 10 of the motor vehicle 2.

The motor vehicle 2 is now set up in the exemplary embodiment for a vehicle occupant 12 who is seated on the vehicle seat 4 according to 3 and 4 a sitting position, to determine a weight class. Depending on the application, two weight classes are specified, for example namely an “adult” weight class and a “child” weight class.

In addition, the motor vehicle 2 in the exemplary embodiment is configured to perform a weight-specific adjustment to at least one safety system 14 of the motor vehicle 2, such as a belt tensioner system or an airbag system, depending on the determined weight class. For this purpose, the safety system 14 is connected to the data processing device 10 via signaling, as shown in 2 is indicated.

To determine the weight class, a weight measurement is first performed using the sensor mat 6. The sensor mat 6 generates basic data and transmits it to the data processing device 10. This basic data represents a measured weight, which depends on the actual weight of the vehicle occupant 12 and the seating position of the vehicle occupant 12.

Simultaneously with the weight measurement, image data is generated by the camera 8 as auxiliary data and transmitted to the data processing device 10. The auxiliary data, i.e. the image data, are evaluated in the data processing device 10 by means of image recognition, whereby in the exemplary embodiment an angle α is determined which represents a tilted position of a seat back 16 of the vehicle seat 4 according to 3 and 4 relative to a seat base 18 of the vehicle seat 4. The angle α serves as a representative value for the seating position of the vehicle occupant 12.

Using the auxiliary data from camera 8, the base data from the weight measurement is now to be processed in order to determine or at least estimate the actual weight of the vehicle occupant 12 based on the measured weight. The base data is mapped to standard data using the auxiliary data, thereby converting the measured weight into a calculated weight that corresponds at least to a good approximation to the actual weight of the vehicle occupant 12.

In the example, the conversion is carried out using a predefined correction function, which is derived from the 5 shown force diagram. From the force equilibrium: $$F_{\text{G}}=F_{\text{S}}+F_{\text{L}}\text{cos }\alpha ={\tilde{F}}_{\text{S}}+{\tilde{F}}_{\text{L}}\text{cos }\tilde{\alpha }$$ and the moment equilibrium: $$F_{\text{S}}a=F_{\text{L}}\frac{2}{3}r$$ surrendered: $${\tilde{F}}_{\text{S}}=F_{\text{S}}\left(\frac{1+\frac{3a}{2r}\text{cos }\alpha }{1+\frac{3a}{2r}\text{cos }\tilde{\alpha }}\right)$$

• - F̃_S die errechnete Gewichtskraft und somit das errechnete Gewicht
• - F_S die gemessene Gewichtskraft, welche senkrecht zur Sitzbasis 18 wirkt, und somit das gemessene Gewicht
• - F_L die messbare Gewichtskraft, welche senkrecht zur Sitzlehne 16 wirkt
• - α der ermittelte Winkel, der die mittels Kamera 8 ermittelte Kippstellung der Sitzlehne 16 des Fahrzeugsitzes 4 gemäß 3 bzw. 4 relativ zu einer Sitzbasis 18 des Fahrzeugsitzes 4 wiedergibt
• - α̃ ein vorgegebener Norm-Winkel, der eine Norm-Kippstellung der Sitzlehne 16 wiedergibt, in der die gemessene Gewichtskraft, welche senkrecht zur Sitzbasis 18 wirkt, und somit das gemessene Gewicht in guter Näherung der tatsächlichen Gewichtskraft entspricht, welche senkrecht zur Sitzbasis 18 wirkt, und somit dem tatsächlichen Gewicht
• - r eine Oberkörperlänge des Fahrzeuginsassen 12
• - s ein Abstand zwischen einem Schwerpunkt der Sitzbasis 18 und einer Kippachse der Sitzlehne 16

This includes:

• - F̃ _S the calculated weight force and thus the calculated weight
• - F _S is the measured weight force acting perpendicular to the seat base 18 and thus the measured weight
• - F _L is the measurable weight force acting perpendicular to the seat back 16
• - α is the angle determined which represents the tilt position of the seat back 16 of the vehicle seat 4 determined by means of camera 8 according to 3 or 4 relative to a seat base 18 of the vehicle seat 4
• - α̃ a predetermined standard angle which represents a standard tilt position of the seat back 16 in which the measured weight force acting perpendicular to the seat base 18 and thus the measured weight corresponds in good approximation to the actual weight force acting perpendicular to the seat base 18 and thus to the actual weight
• - r an upper body length of the vehicle occupant 12
• - s is a distance between a center of gravity of the seat base 18 and a tilt axis of the seat back 16

The quantities r and s are also determined by evaluating the auxiliary data, i.e. the image data, using image recognition.

The bracket now represents a correction factor K with the determined angle α as a parameter. 6 As an example, various values for the correction factor K are shown as a function of different values for the angle α.

7 shows additionally the different values for the correction factor K depending on the different values for a torso angle β according to the SAE standard, where α = 90° - β.

The correction factor K is typically greater the further the angle α deviates from the standard angle α̃. Accordingly, the measured weight deviates further from the actual weight the further the angle α deviates from the standard angle α̃. This is in 8 Here, a limit value G is also given as an example as a boundary between the two weight classes mentioned above, namely the “adult” weight class and the “child” weight class.

In an alternative design variant, instead of a predefined correction function, a trained regression model is used that corrects the measured weight using previously recorded load cases. During development, the system is trained with known load cases with different occupant and backrest positions, as well as with corresponding data from the same occupant in a defined standard position.

LIST OF REFERENCE SYMBOLS:

2

motor vehicle

4

vehicle seat

6

Sensor mat

8

camera

10

Data processing facility

12

Vehicle occupant

14

security system

16

seat back

18

Seat base

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

• US 2022/021957 A1 [0003]

Claims (10)

A method for operating a motor vehicle (2) comprising a sensor device (6, 8) and a data processing device (10), wherein: - a primary sensor unit (6) of the sensor device (6, 8) generates basic data that maps a force acting on a seat surface (18) of a vehicle seat (4) due to the weight of a vehicle occupant (12); - a secondary sensor unit (8) of the sensor device (6, 8) generates auxiliary data that maps a deviation of a seat position of the vehicle occupant (12) from a predetermined standard seat position; and - in a basic operating mode of the motor vehicle (2), the data processing device (10) maps the basic data, based on the auxiliary data, to standard data that maps a force acting on the seat surface (18) of the vehicle seat (4) due to the weight of the vehicle occupant (12) in the predetermined standard seat position. Procedure according to Claim 1 , wherein a weight classification for the vehicle occupant (12) is determined based on the standard data. Procedure according to Claim 1 or 2 , wherein - the auxiliary data are subjected to a plausibility check, - the motor vehicle (2) changes from the basic operating mode to a first auxiliary operating mode if the auxiliary data are assessed as implausible in the course of the plausibility check, and - in the first auxiliary operating mode, the basic data are determined as standard data by means of the data processing device (10). Method according to one of the Claims 1 until 3 , wherein - the basic data are subjected to a plausibility check, - the motor vehicle (2) changes from the basic operating mode to a second auxiliary operating mode if the basic data are assessed as implausible in the course of the plausibility check, and - in the second auxiliary operating mode, the standard data without the basic data are determined based on the auxiliary data by means of the data processing device (10). Method according to one of the Claims 1 until 4 , whereby in the basic operating mode the basic data are mapped to the standard data using a selected mathematical function. Method according to one of the Claims 1 until 4 , whereby in the basic operating mode the basic data are mapped to the standard data using a mapping rule created by machine learning. Method according to one of the Claims 1 until 6 , wherein the secondary sensor unit (8) has a camera (8) and wherein the auxiliary data is generated by means of the camera (8). Method according to one of the Claims 1 until 7 , wherein the secondary sensor unit (8) detects an inclination of a seat back (16) of the vehicle seat (4) by measurement. Motor vehicle (2) configured to carry out a method according to one of the preceding claims in at least one operating mode. Computer program product containing a program executable on a data processing device (10) which, after being started, automatically executes a method according to one of the preceding claims.