DE102017214009A1 - Method and device for detecting the presence and / or movement of a vehicle occupant - Google Patents

Abstract

In the method according to the invention for detecting the presence and / or movement of a vehicle occupant, a signal is emitted in the interior of a vehicle (2) and a reflected signal is detected and evaluated (3). In the evaluation of the reflected signal, at least two operating modes are provided, wherein in a first operating mode by means of the reflected signal is determined (5) whether a seat of the vehicle is occupied by a vehicle occupant and detected in a second mode by means of the reflected signal, a body part of a vehicle occupant becomes and from the movement of the body part a gesture is determined (8).

Description

The present invention relates to a method for detecting the presence and / or movement of a vehicle occupant. The present invention further relates to an apparatus for carrying out the method and to a vehicle that is configured to carry out such a method or has such a device.

Meanwhile, a large number of sensors are installed in motor vehicles, in particular to assist the driver in terms of comfort and safety. The sensors can determine technical parameters of the vehicle, but also information about the vehicle environment, the vehicle interior, the driver or other vehicle occupants. Here, the sensor data of several sensors can be combined or linked to improve the quality of the information obtained. If, for example, the information obtained from one or more sensors is not reliable, this can be partially or completely compensated by means of data from further sensors. Likewise, however, already existing information can be confirmed by means of data from other sensors.

To increase the safety of the driver and other vehicle occupants, it is known with seat occupancy sensors to determine the occupancy of the vehicle seats. This allows security functions of the vehicle to be adapted to the current seat occupancy. Thus, the triggering of an airbag can be specifically controlled as a function of the seat occupancy, wherein the triggering behavior, if necessary. Can also be adapted to the height and weight of the vehicle occupants. Likewise, it can be detected if a seat belt was not put on by one of the vehicle occupants and then a belt alarm is triggered.

Various techniques are used to detect seat occupancy. Frequently, sensors installed in the seats are used in which the pressure load generated by a vehicle occupant located on a seat is determined capacitively. In this case, the reduction in the distance between two conductive layers is measured on the basis of the weight of the person sitting on the seat. The sensors can be provided not only in the seat, but also in the seat back, whereby by the simultaneous use of multiple sensors at different locations of the seat on the height, weight and the exact seating position of the person or a seated or fastened object (eg a child seat) can be closed.

However, the seat occupancy can also be determined, for example, by ultrasound, infrared, camera or radar sensors.

A system for detecting the occupancy of a vehicle seat by means of suitable sensors, for example, in WO 2001/094157 disclosed. Here, the position of an occupant in relation to an airbag of the vehicle is determined with a radar sensor. Based on this, the deployment of the airbag can be adjusted upon a detected impact of the vehicle, so as to reduce the risk of injury to the occupant.

The US 2017/0039835 A1 relates to a radar sensor for detecting seat occupancy, in which a reflected radar signal is evaluated in response to a heartbeat of an occupant. From this, a probability of occupancy of a seat by an occupant is determined, and it can also be recognized whether the seat is occupied by a baby or a child. Depending on the determined probability predefined actions are then selected and made.

It is an object of the invention to provide an improved method and apparatus for detecting the presence and / or movement of a vehicle occupant.

This object is achieved by a method having the features of claim 1 and by a corresponding device according to claim 8. Preferred embodiments of the invention are the subject of the dependent claims.

In the method according to the invention for detecting the presence and / or movement of a vehicle occupant, a signal is emitted in the interior of a vehicle and a reflected signal is detected and evaluated. In the evaluation of the reflected signal at least two modes are provided, it being determined in a first mode by means of the reflected signal whether a seat of the vehicle is occupied by a vehicle occupant and in a second mode by means of the reflected signal, a body part of a vehicle occupant is detected and off the movement of the body part is detected a gesture.

The invention is based here on the recognition that the same or at least similar ranges are used both for the gesture control recently used in motor vehicles, in which a gesture executed by a vehicle occupant in free space is detected and evaluated, as well as for determining the occupancy of vehicle seats the vehicle interior can be detected and therefore can be determined with the same sensor. Due to the multiple use, the Reduce the number of sensors used and thus achieve cost optimization.

Preferably, the radiated signal is a radar signal. Radar signals or the radar sensors emitting them provide a good measurement accuracy for determining the position at high sampling rate and are characterized by a wide detection range with a large opening angle. Likewise, radar sensors have the advantage that they can be obstructed due to the low absorption behind screens or other surface materials in the interior of the motor vehicle.

According to one embodiment of the invention, a safety measure is triggered in the first operating mode when it is determined that a seat of the vehicle is occupied.

According to a further embodiment of the invention, a vehicle function is activated in the second operating mode as a function of the determined gesture.

Advantageously, a distinction is made as to whether the seat of the vehicle is occupied by a vehicle occupant or an object.

Likewise advantageously, the evaluation of the detected reflected signal takes place automatically in the second operating mode, if an occupancy of the seat by a vehicle occupant in the first operating mode has previously been determined.

Advantageously, in the first operating mode, a comparison is made with reference data which are based on a calibration on an empty interior of the vehicle.

Accordingly, a device according to the invention for detecting the presence and / or movement of a vehicle occupant comprises at least one arranged in the interior of the motor vehicle sensor unit which emits a signal in the interior of the motor vehicle and detects a reflected signal and an evaluation and control unit, the data from the sensor unit to Evaluation be supplied. Here, the evaluation and control unit on at least two modes, which is determined in a first mode by means of the reflected signal whether a seat of the vehicle is occupied by a vehicle occupant and in a second mode by means of the reflected signal, a body part of a vehicle occupant is detected and off the movement of the body part is detected a gesture.

According to one embodiment of the invention, the at least one sensor unit is designed as a radar sensor which emits a radar signal in the interior of the motor vehicle and detects a reflected radar signal.

According to a further embodiment of the invention, a memory unit is provided in which reference data for the region covered by the signal of the interior are stored, wherein the reference data based on a calibration on an empty interior of the vehicle, and the evaluation and control unit in the first mode determined by comparing the detected reflected radar signal with the reference data whether a seat of the vehicle is occupied by a vehicle occupant.

The invention also relates to a motor vehicle in which the method according to the invention or the device according to the invention is used.

• 1 zeigt schematisch das erfindungsgemäße Verfahren zur Erkennung der Anwesenheit und/oder Bewegung eines Fahrzeuginsassen; und
• 2 zeigt schematisch ein Blockschaltbild einer erfindungsgemäßen Vorrichtung.

Further features of the present invention will become apparent from the following description and claims taken in conjunction with the figures.

• 1 shows schematically the inventive method for detecting the presence and / or movement of a vehicle occupant; and
• 2 schematically shows a block diagram of a device according to the invention.

For a better understanding of the principles of the present invention, embodiments of the invention will be explained in more detail below with reference to the figures. It should be understood that the invention is not limited to these embodiments, and that the features described may also be combined or modified without departing from the scope of the invention as defined in the claims.

1 schematically shows the inventive method for detecting the presence and / or movement of a vehicle occupant. According to process step 1 First of all, a calibration is performed on an empty interior of the vehicle in order to be able to calculate reflections on features of the interior, in particular for a recognition of the seat occupancy. In this case, reference data for the region covered by the radar signal of the interior space are determined and stored in order to use this for a later comparison with reflected radar signals can.

This method step can already be carried out at the factory, wherein the reference data can then be generated from the design data of the vehicle or also from a measurement of reflected radar signals during production. Likewise, the reference data can also be generated at the customer. This can be unique when taking over the vehicle or even be carried out regularly. For example, a detection of the reflected radar signals can be carried out in each case when the vehicle is closed or opened.

In process step 2 radar waves are then radiated from a mounted in the interior of the vehicle radar sensor. If a vehicle occupant is in the vehicle, the radar waves are reflected inter alia on body parts of the vehicle occupant, such as, for example, the upper body or the hands, but also on features of the interior. The reflected radar waves become in a subsequent process step 3 detected and evaluated by the radar sensor.

In one process step 4 It is first determined whether there is currently a first mode in which the occupancy of a vehicle seat is determined by a vehicle occupant.

If this is the case, then in one process step 5 checked by comparing the reflected radar signals with the reference data for an empty vehicle interior, whether there is a change in the area of a vehicle seat. In the case of a change, the shape of the object located on the vehicle seat can also be determined from the reflected radar signals in order to carry out a classification. Thus, it can be determined whether in fact a vehicle occupant is on the vehicle seat or instead of a person, for example, a bag was placed on the vehicle seat. Likewise, for example, a child seat mounted on the vehicle seat can be detected.

If appropriate, in addition to the shape, it may also be determined whether a movement takes place in the detected region and, if appropriate, a course of motion or movement pattern is determined and used for the classification. This can be done by evaluating the reflected radar signals for several consecutive times or a Doppler shift of the reflected radar signals.

If a seat is detected as occupied, this can be done in one step 6 be used for the triggering of a safety measure or the activation of other vehicle functions.

Thus, it can be detected if, during driving, a safety belt was not put on by one of the vehicle occupants and then a belt alarm in the form of an acoustic or optical warning signal is triggered. This is particularly helpful for the seat belts of the passenger and possibly other passengers in the vehicle, as for this, unlike the driver, from the driving of the vehicle can not be concluded on an occupancy of the corresponding vehicle seat. Likewise, it can be dispensed with the triggering of a Gurtalarms when the evaluation of the radar signals shows that the corresponding seat is not occupied by a person.

Furthermore, the triggering of an airbag can be made dependent on whether a vehicle occupant was detected on a vehicle seat or prevented when a rear-facing child seat was detected. Even before the occurrence of a dangerous situation in the installation of the child seat immediately a warning can be made, which is reminiscent of the endangerment of the child in the child seat by the airbag and possibly prompts for switching off the airbag.

Furthermore, seatbelt pre-tensioners or an extendable roll bar can also be controlled automatically based on the detected seat occupancy.

Finally, the control based on a recognized seat occupancy is not limited to components of the safety system of the vehicle. For example, it is also possible to automatically activate an assistance or infotainment system when recognizing the seat occupancy. Also, for example, a display for the passenger or passengers on the rear seat of the vehicle can be automatically activated when an occupancy of the corresponding vehicle seat is detected or are automatically deactivated when the corresponding vehicle seat is no longer occupied.

If the first mode should not be present, is in one step 7 determines whether a second mode to be determined in the gestures of a vehicle occupant is present.

If this is the case, the gesture control determines the type of movement performed by determining the spatial position of the gesture-executing body part of the vehicle occupant at different times. By means of the resulting movement trajectory can then in a process step 8th the executed gesture will be recognized. Subsequently, the vehicle function associated with the detected gesture is determined and in a method step 9 executed.

It can be provided that when opening a previously closed vehicle door, for example by means of a key of the vehicle, a keyless go access or a fingerprint recognition, first an evaluation of the reflected radar signals in the first mode is carried out by occupancy of a seat to determine a vehicle occupant, as a Gesture control by the vehicle occupant usually does not take place immediately when opening a vehicle door or when getting into the vehicle, but only after this has taken place on a vehicle seat. On the second mode for detecting a gesture of the vehicle occupant is then automatically switched when an occupancy of the seat is detected by the vehicle occupant.

2 schematically shows a block diagram of a device according to the invention. It is at least one radar sensor 10 provided based on the emission of a radar wave and the evaluation of a received echo. From the duration of the radar wave and possibly the frequency difference of the returning radar wave due to the Doppler effect both the distance and the speed of the reflecting object can be determined spatially resolved. The radar waves can be emitted here in a pulse mode or in a continuous wave mode. In pulsed operation, radar pulses separated from one another are emitted which, for example, each have a duration in the microsecond range. In continuous wave mode, the radar signal is preferably frequency-modulated. Is only a single radar sensor 10 provided, it may preferably be installed in the region of the roof module or the dashboard or the center console, as is typically done before this area a gesture input by the driver or possibly front passenger and so, as well as the occupancy of driver and passenger seat, well recorded can be. Preferably, the antenna characteristic of the radar sensor should be matched to the vehicle interior for detection of the seats and to the detection area for gestures.

From the radar sensor 10 become sensor data of an evaluation and control unit 12 supplied, which then determines a seat occupancy by a vehicle occupant or gestures of a vehicle occupant depending on the current operating mode.

For gesture recognition, the reflected radar signals are detected over a certain period of time to determine from the change in the detected radar signals in this period of time, the gesture performed by the vehicle occupant, for example, with his hand. Thus, for example, the vehicle occupant can perform a swipe gesture in a horizontal or vertical direction with his hand, in which case the swipe gesture can then be determined from the position of the hand determined with the reflected radar signals at different points in time. To optimize the measurement accuracy, the Doppler shift of the received radar signals can additionally be determined here. A reduction in the computational effort can be achieved if the evaluation of the reflected radar signals are restricted to areas in which a vehicle occupant typically executes a gesture. For example, the evaluation can be made only for the spatial area left and right of the steering wheel, since typically in this area the driver of the vehicle makes a gesture with his hands. In this case, both a movement of the entire hand can be recognized as a gesture or else, with sufficient accuracy of the radar sensor used, the position and movement of individual fingers for so-called micro gestures.

The position and speed information become a gesture recognition unit 13 fed, for example, by comparison with in a memory 11 discarded movement trajectories of various gestures one of these gestures determined. In this case, it is advantageous for the recognition if only a limited selection of gestures is implemented or, depending on the context, is active for evaluation. Also for the vehicle occupants a limited number of gestures is advantageous because they are then easier to learn or retain. In the store 11 Movement trajectories can also be stored which should not represent a gesture but serve, for example, the actuation of operating elements. In this way, a wrong assignment to a gesture with a similar movement can be prevented.

The various in the store 11 Stored gestures are assigned different vehicle functions that are to be executed in the case of determinations of the respective gesture. This assignment can already be made at the factory, or even done by the user of the vehicle. Here also different user profiles for different users of the vehicle can be created.

Since different users can execute differently pronounced movement patterns for the same gesture, a training or learning phase for the respective user can first be carried out to improve the recognition of the gestures. Here, the user can be informed, for example, by an advertisement on a display of the vehicle or an acoustic output as he has to perform a certain gesture. If the user actually executes this gesture, the positional change caused thereby can be determined from the detected radar signals. This individual movement trajectory can then be stored for the trained gesture and used in the future. However, this can also be achieved by the factory acquisition of many individual user gestures, which then train AI-based algorithms for evaluation. Together with context-related less active gestures, a high Detection rate can be achieved without subsequent learning by the user.

Information about the detected gesture is then forwarded to an unillustrated unit for performing a vehicle function that executes the vehicle function associated with the gesture. Thus, for example, an infotainment unit can be activated by means of the recognized gesture in order to change the title during an audio playback, to change the volume of the audio playback or to accept or reject a telephone call.

Furthermore, the gesture recognized by the gesture recognition unit may be communicated to the vehicle occupant who made the gesture. For this purpose, an indication can be made on a display in the field of vision of the vehicle occupant. Instead or in addition, an audible indication of one or more speakers can be output. Optionally, execution of the detected gesture may then be made conditional upon additional confirmation by the vehicle occupant. Likewise, an indication to the vehicle occupants can be output if the gesture could not be clearly recognized by the gesture recognition unit.

For detecting the occupancy of a vehicle seat by a vehicle occupant, as described above, by the evaluation and control unit 12 reflected radar signals in the memory unit 11 stored reference data for an empty vehicle interior compared, whereby the shape or a movement pattern for classification can be determined.

If a seat is detected as occupied, then the evaluation and control unit 12 then components of a safety system of the vehicle, such as a Gurtalarmeinrichtung 14 or an airbag device 15 , or also suitably control other components of the vehicle electronics.

The analysis and control unit 12 may include a microprocessor, an internal electronic memory, and one or more electrical interfaces. Via the electrical interfaces, for example via a CAN or Ethernet bus system, a communication with the radar sensor 10 the store 11 , the gesture recognition unit 13 , the belt alarm device 14 , the airbag device 15 and, if necessary, further control devices for further vehicle functions.

The invention can be used in any areas of vehicle technology.

LIST OF REFERENCE NUMBERS

1

Calibration on empty interior

2

Transmission of a radar signal

3

Acquisition and evaluation of the reflected radar signal

4

Query whether a first operating mode exists

5

Detection of seat occupancy

6

Triggering a security measure

7

Query whether a second operating mode exists

8th

Detecting a gesture

9

Control vehicle function

10

Radar sensor unit

11

storage unit

12

Evaluation and control unit

13

Gesture recognition unit

14

Belt alarm device

15

Air bag device

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

• WO 2001/094157 [0006]
• US 2017/0039835 A1 [0007]

Claims (11)

Method for detecting the presence and / or movement of a vehicle occupant, in which a signal is emitted (2) in the interior of a vehicle and a reflected signal is detected and evaluated (3), characterized in that when evaluating the reflected signal at least two modes are provided, wherein detected in a first mode by means of the reflected signal (5) whether a seat of the vehicle is occupied by a vehicle occupant and in a second mode by means of the reflected signal, a body part of a vehicle occupant is detected and from the movement of the body part a gesture determined (8) becomes. Method according to Claim 1 wherein the radiated signal is a radar signal. Method according to Claim 1 or 2 In the first operating mode, a safety measure is triggered (6) when it is determined that a seat of the vehicle is occupied. Method according to one of the preceding claims, wherein in the second operating mode a vehicle function is activated (9) as a function of the determined gesture. Method according to Claim 3 in which a distinction is made as to whether the seat of the vehicle is occupied by a vehicle occupant or an object. Method according to one of the preceding claims, wherein the evaluation of the detected reflected signal is carried out automatically in the second mode, if previously a occupancy of the seat has been determined by a vehicle occupant in the first mode. Method according to one of the preceding claims, wherein in the first mode of operation, a comparison with reference data, which are based on a calibration (1) on an empty interior of the vehicle takes place. Device for detecting the presence and / or movement of a vehicle occupant, comprising at least one arranged in the interior of the motor vehicle sensor unit (10) which emits a signal in the interior of the motor vehicle and detects a reflected signal and an evaluation and control unit (12), the data supplied by the sensor unit (10) for evaluation, characterized in that the evaluation and control unit (12) has at least two modes, wherein in a first mode by means of the reflected signal is determined whether a seat of the vehicle is occupied by a vehicle occupant and In a second operating mode by means of the reflected signal, a body part of a vehicle occupant is detected and a gesture is determined from the movement of the body part. Device after Claim 8 , wherein the at least one sensor unit (10) is designed as a radar sensor which emits a radar signal in the interior of the motor vehicle and detects a reflected radar signal. Device after Claim 8 or 9 in which a memory unit (11) is provided, in which reference data for the region of the interior covered by the signal is stored, the reference data being based on a calibration on an empty interior of the vehicle, and the evaluation and control unit (12) in FIG first mode by comparing the detected reflected radar signal with the reference data determines whether a seat of the vehicle is occupied by a vehicle occupant. Motor vehicle, which is set up, a method according to one of Claims 1 to 7 to execute or a device according to one of Claims 8 to 10 having.

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