Method for monitoring an interior for a motor vehicle with at least one ultrasound system, interior monitoring device for a motor vehicle, and motor vehicle

Abstract

A method for monitoring an interior (6) for a motor vehicle (1), comprising the following steps: - transmitting at least one ultrasonic signal by means of an ultrasonic transmitter (4); - providing reception information items (13a, 13b) which are generated depending on the transmitted ultrasonic signal; - providing reference data (14a, 14b) representing a past state of the interior (6); - comparing at least one reception information item (13a, 13b) of the reception information items (13a, 13b) with the reference data (14a, 14b) in order to generate at least one deviation value (17a, 17b, 28); - determining at least one distance (23, R) of the at least one reception information item (13a, 13b) from the ultrasonic transmitter (4); - determining at least one angle (20, φ) between the at least one deviation value (17a, 17b, 28) and an axis of the motor vehicle (1); - determining a state (27) of the interior (6) depending on the at least one deviation value (17a, 17b, 28) and depending on the at least one distance (23, R) and the at least one angle (20, φ).

Description

[0001] Method for monitoring an interior of a motor vehicle with at least one ultrasound system, interior monitoring device for a motor vehicle and motor vehicle

[0002] One aspect of the invention relates to a method for monitoring the interior of a motor vehicle using at least one ultrasound system. Another aspect of the invention relates to an interior monitoring device for a motor vehicle. Yet another aspect of the invention relates to a motor vehicle.

[0003] Monitoring access to the interior of a motor vehicle is a well-known practice. Electronic systems are used for this purpose, which, for example, also carry out and verify authorization queries. However, the detection accuracy for intrusion detection is relatively inaccurate. This leads to misinterpretations, which lead to the unwanted triggering of alarm signals.

[0004] The invention is based on the object of creating a method, an interior monitoring device and a motor vehicle with which a state of an interior of a motor vehicle with regard to a break-in can be determined in an improved manner.

[0005] The object is achieved by the subject matter of the independent claims. Advantageous developments of the invention are defined by the dependent claims, the following description, and the figures.

[0006] One aspect of the invention relates to a method for monitoring a motor vehicle interior using at least one ultrasound system. The method preferably comprises the following steps:

[0007] In particular, emitting at least one ultrasonic signal by means of an ultrasonic transmitter of the ultrasonic system;

[0008] In particular, providing reception information generated depending on the emitted ultrasonic signal;

[0009] In particular, providing reference data representing a past state of the interior; in particular, comparing at least one piece of received information with the reference data to generate at least one deviation value;

[0010] In particular, determining at least one distance of the at least one piece of received information from the ultrasonic transmitter;

[0011] In particular, determining at least one angle of the at least one deviation value to an axis, in particular a longitudinal axis, of the motor vehicle;

[0012] In particular, determining a state of the interior depending on the at least one deviation value and depending on the at least one distance and the at least one angle.

[0013] This provides a method that enables improved and reliable determination of the condition of the interior with respect to unauthorized or unwanted access, such as a break-in. This is particularly true when access to the vehicle is gained through a partially open window or through a gap in the open top of a convertible, for example.

[0014] A particularly advantageous feature is that not individual objects are detected, but rather an evaluation of at least one deviation value is performed, thus indirectly detecting objects. The at least one deviation value is also evaluated with respect to a position. This reduces false alarms.

[0015] In particular, the ultrasonic signal is an ultrasonic wave. The ultrasonic transmitter preferably emits a burst, such as a rectangular pulse, lasting 1 ms, for example. For example, the ultrasonic wave is reflected by an object in the vehicle's surroundings, such as the interior. For example, the ultrasonic system has an ultrasonic receiver.

[0016] If necessary, the ultrasonic receiver receives the reflected ultrasonic wave and generates a received signal depending on the reflected ultrasonic wave. The received signal is, in particular, an electrical voltage signal. The electrical voltage signal is sampled and stored, for example, at different sampling times. A sampling period between two sampling times is preferably between 10 ps and 1 ms, in particular between 300 ps and 700 ps, ​​in particular 500 ps. The received information is preferably values ​​of the sampled voltage signal. These can, in particular, be referred to as voltage values.

[0017] Optionally, a voltage value of the voltage signal is stored for each sampling time.

[0018] For example, the reference data contains sampled values ​​of additional voltage signals determined during previous measurements. If appropriate, the reference data contains the sampled values ​​of the last 100 measurements, in particular the last 20 measurements, in particular the last 10 measurements. A measurement is, in particular, a single execution of the method. Optionally, the reference data contains deviation values ​​from the last measurements.

[0019] To determine the at least one deviation value, for example, a difference between the reference data and the received information is determined. Preferably, a statistical value, in particular a variance and / or a standard deviation, is determined to determine the at least one deviation value.

[0020] In particular, the received information and the reference data are provided to an evaluation unit of the ultrasound system. For example, the determined state is provided, in particular, to the evaluation unit.

[0021] In particular, the at least one distance is a radius with the ultrasonic transmitter as its center. For example, the at least one distance is determined depending on one of the sampling times. In particular, the at least one distance R is determined according to the following formula:

[0022] R = sampling time ■ cs ■ 0.5

[0023] Where R is the distance and cs is the speed of sound. For example, the ultrasonic receiver receives for more than 10 ms, especially between 15 ms and 20 ms, especially for 17.5 ms. For 17.5 ms, any reflected ultrasonic waves are received, for example, from a distance of 3 meters from the ultrasonic transmitter.

[0024] However, it is also possible for the distance to be determined via triangulation. For this purpose, two ultrasonic receivers are used, in particular. In this option, the two ultrasonic receivers are spaced apart from each other, for example, between 1 cm and 200 cm, in particular between 10 cm and 100 cm. It is possible for the angle to be determined relative to the longitudinal axis of the motor vehicle. Alternatively, the angle can be determined relative to a transverse axis of the motor vehicle. In particular, when the distance is determined via triangulation, two angles are determined relative to the transverse axis of the motor vehicle.

[0025] The interior space can, for example, have at least two different states. A first state represents, in particular, that there has been a change in the occupancy of the interior space with an object, and a second state represents that there has been no change in occupancy. Alternatively or additionally, one state represents, in particular, that a break-in has occurred, and another state represents that no break-in has occurred. In particular, an alarm is triggered depending on the state. The alarm is, for example, a visual and / or acoustic signal.

[0026] In particular, the at least one deviation value is assessed with respect to the burglary event and, if applicable, with respect to a position of the burglary event.

[0027] This procedure can reduce overall incorrect assessments of the interior's condition, thus reducing false alarms.

[0028] In one embodiment, to determine the at least one deviation value, at least one standard deviation is determined depending on the reference data and the at least one piece of received information.

[0029] This allows for a more accurate determination of a change between the received information and the deviation value. This way, a change in the occupancy status is determined indirectly. In particular, a standard deviation is determined for each voltage value. In particular, the larger the at least one standard deviation, the greater the change in position.

[0030] In particular, at least one variance value is determined to determine the at least one deviation value. For example, the at least one variance value is determined according to the following formula: A / ? = (K — avg reference dataA ) 2Here, VAR is at least one variance value, V is the deviation value, and avg is an average calculation. Specifically, a variance value VAR is calculated for each voltage value V. In this case, avg(ReferenceDataA) is the average of the past voltage values. For example, the average also includes the current voltage value V.

[0031] For example, depending on the at least one variance value, the at least one

[0032] Standard deviation is determined. In particular, at least one

[0033] Standard deviation determined according to the following formula:

[0034] In this embodiment, the reference data B contains the past variances, for example, the last n measurements. For example, the reference data B contains the currently calculated variance. In this case, it is divided by n+1 instead of n.

[0035] In one embodiment, to determine the at least one deviation value, the at least one standard deviation is multiplied by an adjustment factor. This can increase the accuracy of the method.

[0036] For example, the adjustment factor has a value between 0 and 10, in particular between 0 and 7. In particular, the adjustment factor is adjusted dynamically.

[0037] In one embodiment, to determine the state of the interior, it is checked whether the at least one deviation value exceeds a limit value and whether the at least one deviation value lies within the interior according to the at least one distance and the at least one angle. This reliably detects, in particular, a change in the occupancy state. In particular, this prevents an alarm from being triggered even though the change or object is located outside the interior. This can reduce false alarms.

[0038] In particular, the change in the at least one piece of received information compared to the reference data is greater the larger the at least one deviation value is. For example, if an object is located in the interior that was not there when the reference data was generated, then the at least one piece of received information will be significantly different from the reference data. This difference is represented in particular by the at least one deviation value.

[0039] In particular, the difference arises because the object causes a reflection of the ultrasonic waves at a position in the interior where no reflection occurred when the reference data was generated.

[0040] For example, the interior space is divided into angular areas. Preferably, one vertex of the angle is located at a position of the ultrasonic transmitter.

[0041] Preferably, each angular range is assigned a limit distance. For example, if the at least one distance exceeds the limit distance of the angular range in which the at least one angle is located, then the at least one deviation value lies outside the interior space.

[0042] Preferably, it is first determined whether the at least one deviation value exceeds the limit value. If this is the case, in particular only if it is, then a check is carried out to determine whether the at least one deviation value lies within the interior space according to the at least one distance and the at least one angle. This allows the condition to be determined more quickly, if necessary.

[0043] The limit value is, for example, between 5 and 55, in particular between 10 and 30, in particular between 15 and 25, in particular 20. In particular, the limit value has the same unit as the at least one deviation value, for example millivolts.

[0044] In one embodiment, the state of the interior is a temporary occupancy state. The occupancy state of the interior is particularly dynamically variable. For example, the occupancy state changes if an object is located in the interior that was previously not present, particularly during the last measurements.

[0045] In one embodiment, the occupancy state is assessed as unauthorized if the theft of the vehicle or an object from the interior is detected. Thus, it is not only determined whether a deviation value exceeding the threshold is present in the interior, but also, for example, whether the object is stolen. This further reduces false alarms. In particular, this check is performed if the threshold is exceeded in the interior. In particular, the occupancy state is then assessed as a break-in. If the condition or the occupancy state is assessed as a break-in, the alarm is triggered if necessary.

[0046] In particular, information is provided that the motor vehicle is parked and no vehicle key authorizing access can be detected. This prevents, in particular, an alarm from being triggered even though access to the interior was authorized.

[0047] In one embodiment, the at least one distance and the at least one angle are converted into Cartesian coordinates. Thus, circular coordinates are converted into xy coordinates. In particular, the Cartesian coordinates are vehicle coordinates. The Cartesian coordinates can also include a height coordinate. Using the Cartesian coordinates, it is possible to determine more quickly whether the at least one deviation value is located within the vehicle interior.

[0048] In one embodiment, a map is generated that represents the surroundings of the motor vehicle and the interior of the motor vehicle. The map is divided into sub-areas, in particular in a grid-like manner. In particular, a deviation value is assigned to several of the sub-areas depending on the Cartesian coordinates. Thus, several deviation values ​​are determined and each is assigned to one of the sub-areas. In particular, a position designated by the Cartesian coordinates is assigned to each of the deviation values. This allows for quick and improved determination of where the at least one deviation value lies, in particular if the at least one deviation value exceeds the limit value.

[0049] Alternatively or additionally, it is provided that different deviation values ​​are assigned to each sub-area and / or different detection parameters, such as a detection threshold, a detection duration or a detection delay, are defined for each sub-area.

[0050] In one embodiment, the comparison with the limit value is carried out for each sub-area with the assigned deviation value. This makes it possible to determine, in particular, where one of the deviation values ​​exceeds the limit value. This can reduce false alarms because, for example, the alarm is not triggered if the limit value is exceeded outside the interior. In one embodiment, the received information contains first received information and second received information. The reference data contains first reference data and second reference data. At least one first received information item of the first received information is compared with the first reference data to generate at least one first deviation value. A second received information item of the second received information is compared with the second reference data to generate at least one second deviation value.The first received information is generated by a first ultrasonic receiver of the ultrasound system based on the transmitted ultrasonic signal. The second received information is generated by a second ultrasonic receiver of the ultrasound system based on the transmitted ultrasonic signal. In particular, the first received information and the second received information have the same sampling times.

[0051] This allows an angle and a distance between the at least one first deviation value and the at least one second deviation value to be determined more precisely. This allows the position of the deviation value and thus the condition of the interior to be determined more accurately.

[0052] For example, the first ultrasonic receiver and the second ultrasonic receiver are aligned in different receiving directions. For example, they form an angle of less than 180 degrees. For example, the angle between the first ultrasonic receiver and the second ultrasonic receiver is less than 90 degrees, in particular, the angle is 20 degrees. In particular, the first ultrasonic receiver and the second ultrasonic receiver are each rotated by half the angle between them relative to the longitudinal axis, for example, by 10° each.

[0053] In one embodiment, the at least one angle is determined as a quotient of the at least one first deviation value and the at least one second deviation value. This allows for an improved determination of the at least one angle.

[0054] For example, the quotient is first determined according to the following formula: first deviation value — second deviation value quotient = - — - — - : - — - — - first deviation value + second deviation value

[0055] In particular, a quotient is determined for each sampling point.

[0056] Optionally, the quotient corresponds to a ratio of a first sound pressure level and a second sound pressure level, wherein the first sound pressure level is received by the first ultrasonic receiver and the second sound pressure level is received by the second ultrasonic receiver. According to its reception characteristics, the ultrasonic receiver detects, for example, ultrasonic signals from an area in front of the ultrasonic receiver as a sum signal of a cone, with a signal strength decreasing towards the outside. The ultrasonic receiver therefore receives, for example, the ultrasonic signal of a circular sector with different weighting at a sampling time. In particular, in one embodiment, a change in the voltage signal of the two ultrasonic receivers is received, and the angle of the change or standard deviation is determined via the ratio of the standard deviation and the described reception characteristics.

[0057] If necessary, at least one angle is determined depending on the quotient according to the following formula:

[0058] Angle = angle slope ■ quotient + angle offset

[0059] For example, the angular gradient is between 50° and 150°, in particular between 90° and 110°, in particular 100.4°. For example, the angular offset is between 0.10° and 0.50°, in particular between 0.25° and 0.35°, in particular 0.30°. In particular, one angle is determined per sampling time.

[0060] In one exemplary embodiment, the sub-regions are divided into first sub-regions and second sub-regions. In particular, first deviation values ​​are assigned to the first sub-regions and second deviation values ​​are assigned to the second sub-regions. This particularly increases the accuracy of the method. Preferably, a positive angle relative to the axis corresponds to the first sub-region and a negative angle relative to the axis corresponds to the second sub-region. In particular, the first ultrasonic receiver is oriented in a direction of the first sub-regions and the second ultrasonic receiver is oriented in a direction of the second sub-regions. For example, a left vehicle half is assigned to the first ultrasonic receiver and a right vehicle half is assigned to the second ultrasonic receiver.

[0061] In one embodiment, the ultrasound system is mounted on a vehicle roof. This allows for easy detection of the vehicle's interior.

[0062] In one embodiment, the ultrasonic transmitter transmits the ultrasonic signal with a primary transmission direction toward a center console of the motor vehicle. This alignment of the ultrasonic transmitter toward a central area of ​​the vehicle improves detection of the interior.

[0063] In one exemplary embodiment, the ultrasound system, in particular with the ultrasound transmitter and the ultrasound receiver, can be arranged on a roof control module. In particular, the ultrasound system, in particular with the ultrasound transmitter and the ultrasound receiver, can be arranged on an interior mirror module of the motor vehicle.

[0064] A further aspect of the invention relates to an interior monitoring device for a motor vehicle. It can therefore be referred to as a motor vehicle interior monitoring device. The interior monitoring device has at least one ultrasound system with an ultrasound transmitter, an ultrasound receiver, in particular a first ultrasound receiver and a second ultrasound receiver, and an evaluation unit. It is also possible for the ultrasound system to have two ultrasound transmitters. For example, the two ultrasound transmitters transmit a burst simultaneously. In particular, the two ultrasound transmitters are designed as transceivers and are thus configured as ultrasound receivers. This can be referred to as a two-sensor system. The interior monitoring device is configured to carry out the method for monitoring the interior or an embodiment thereof. In particular, the interior monitoring device carries out the method.

[0065] The interior monitoring device can, in particular, be an anti-theft device. In this case, it can, in particular, be a vehicle anti-theft device. A further aspect of the invention relates to a motor vehicle with the interior monitoring device.

[0066] Further embodiments of the method for monitoring an interior space follow directly from the various embodiments of the further aspects of the invention mentioned, and vice versa. In particular, individual features and corresponding explanations, as well as advantages relating to the various embodiments of the method according to the invention, can be transferred analogously to corresponding embodiments of the further aspects of the invention. One of the further aspects of the invention can also be further developed by features and embodiments of the respective further aspects of the invention.

[0067] Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, embodiments are to be regarded as encompassed and disclosed by the invention that are not explicitly shown and explained in the figures, but which emerge and can be produced by separate combinations of features from the explained embodiments. Embodiments and combinations of features are also to be regarded as disclosed that therefore do not have all the features of an originally formulated independent claim.Furthermore, embodiments and combinations of features are to be regarded as disclosed, in particular by the embodiments set out above, which go beyond or deviate from the combinations of features set out in the reliances of the claims.

[0068] Exemplary embodiments of the invention are described below. They show:

[0069] Fig. 1 is a schematic representation of an embodiment of a motor vehicle according to the invention; Fig. 2 is a schematic flow diagram of an embodiment of a method according to the invention for monitoring an interior of the motor vehicle;

[0070] Fig. 3 is a schematic map of an embodiment of the method according to the invention;

[0071] Fig. 4 is a schematic block diagram of an embodiment of an interior monitoring device according to the invention.

[0072] Fig. 1 shows a schematic plan view of a motor vehicle 1. The motor vehicle 1 has an interior monitoring device 2. This is an anti-burglary device, in particular an anti-theft device, in particular a vehicle anti-theft device. This enables theft protection for the entire motor vehicle 1. But it also enables potential theft protection of objects from the motor vehicle 1. The interior monitoring device 2 has at least one ultrasound system 2a. The interior monitoring device 2 has, in particular, an evaluation unit 3, at least one ultrasound transmitter 4, and at least one ultrasound receiver, in particular a first ultrasound receiver 5a and a second ultrasound receiver 5b.For example, a first main receiving direction 7a of the first ultrasonic receiver 5a is oriented at an angle α relative to a second main receiving direction 7b of the second ultrasonic receiver 5b. In particular, the angle α is between 0° and 180°, in particular between 5° and 90°, in particular between 10° and 45°, in particular 20°. Preferably, a main transmission direction of the ultrasonic transmitter 4 is oriented toward a center console of the motor vehicle 1. The ultrasonic transmitter 4 and the ultrasonic receivers 5a, 5b can be designed as transceivers. The motor vehicle 1 has, in particular, a longitudinal axis 1a, which is oriented, in particular, parallel to a direction of travel. The motor vehicle 1 has an interior 6 for persons. The interior 6 has a transverse extent 8 and a longitudinal extent 9. The interior monitoring device 2 can, for example, be arranged on a roof control module of the motor vehicle 1.This enables particularly advantageous direct detection of the door areas.

[0073] The interior monitoring device 2 is activated, for example, when the motor vehicle 1 is parked. In particular, it is activated when an authorized user of the motor vehicle 1 has left the motor vehicle 1 and, in particular, a locking device is activated, thus locking the doors of the motor vehicle 1. In this active state of the interior monitoring device 2, the interior monitoring device 2 executes, in particular, steps S1 to S7 (Fig. 2).

[0074] Fig. 2 shows a schematic flow diagram. In a step S1, at least one ultrasonic signal is transmitted by means of the ultrasonic transmitter 4 of the ultrasonic system 2a.

[0075] In a step S2, received information 13a, 13b (Fig. 4) is provided. The received information 13a, 13b is generated depending on the transmitted ultrasonic signal. In particular, the received information 13a, 13b is generated by the at least one ultrasonic receiver. For example, the at least one ultrasonic receiver generates a voltage signal and provides it as sampled voltage values, in particular to the evaluation unit 3, as received information 13a, 13b.

[0076] In a step S3, reference data 14a, 14b (Fig. 4) representing a past state of the interior 6 are provided. In particular, the reference data 14a, 14b comprise reception information and / or deviation values ​​from previous method runs. For example, the method is executed every two seconds, in particular every second, especially in the active state.

[0077] In a step S4, at least one piece of reception information 13a, 13b of the reception information 13a, 13b is compared with the reference data 14a, 14b to generate at least one deviation value 28 (Fig. 3).

[0078] In a step S5, at least one distance R (Fig. 3) of the at least one received information 13a, 13b to the ultrasonic transmitter 4 is determined.

[0079] In a step S6, at least one angle (p (Fig. 3)) of the at least one deviation value 28 to an axis, in particular the longitudinal axis 1 a, of the motor vehicle 1 is determined.

[0080] In a step S7, a state 27 (Fig. 4) of the interior 6 is determined as a function of the at least one deviation value 28 and as a function of the at least one distance R and the at least one angle (p). In particular, the state 27 of the interior 6 is a temporary occupancy state of the interior 6. The occupancy state is, in particular, dynamically variable. For example, the occupancy state is assessed as unauthorized if a theft of the motor vehicle 1 or an object from the interior 6 is detected. In particular, an alarm is triggered as a function of the state 27. For example, the alarm is output as an acoustic and / or optical signal.

[0081] For example, information is provided to the evaluation unit 3 of the interior monitoring device 2 as to whether the motor vehicle 1 is parked and whether a vehicle key authorizing access to the motor vehicle 1 can be detected. In particular, in one example, the alarm is also triggered based on this information. In particular, the alarm can be triggered precisely when the motor vehicle 1 is parked and no vehicle key authorizing access can be detected, and the interior 6 is assessed as being occupied by unauthorized persons.

[0082] Fig. 3 shows a schematic map 10 representing the surroundings of the motor vehicle 1 and the interior 6 of the motor vehicle 1. In particular, the map is generated by the evaluation unit 3 after step S6 and before step S7. The map 10 is, in particular, divided into subregions 11 in a grid-like manner. In particular, the map 10 has an origin 12. This origin is located, for example, at a position of the ultrasonic transmitter 4.

[0083] In particular, after performing step S6, the at least one angle (p) and the at least one distance R are converted into Cartesian coordinates x, y, z of the map 10. For example, only the coordinates x, y of the transverse extent 8 and the longitudinal extent 9 are calculated.

[0084] However, it is also possible for a z-coordinate to be calculated in the height direction. In this case, the ultrasound system 2a preferably has more than two, in particular exactly four, ultrasound receivers 5a, 5b.

[0085] Where appropriate, each sub-area 11 has coordinates x, y, z in transverse dimension 8 and in longitudinal dimension 9 and in particular in the height direction.

[0086] Preferably, a deviation value 28 is determined for a plurality of received information items of the received information 13a, 13b, in particular for all received information items 13a, 13b. In particular, a deviation value 28 is assigned to each sub-area 11.

[0087] Fig. 4 shows a schematic block diagram, in particular of the evaluation unit 3.

[0088] For example, the first ultrasonic receiver 5a generates first received information 13a of the received information 13a, 13b. For example, the second ultrasonic receiver 5b generates second received information 13b of the received information 13a, 13b. In particular, the first received information 13a and the second received information are generated substantially at the same time. In particular, first reference data 14a and second reference data 14b of the reference data 14a, 14b are provided.

[0089] In one embodiment, first variances 15a are determined based on the first reference data 14a and the first received information 13a. For example, first standard deviations 16a are determined based on the first variances 15a and the first reference data 14a. Preferably, first deviation values ​​17a are determined based on the first standard deviations 16a and a first adjustment factor 18a. For example, the first deviation values ​​17a contain the at least one deviation value 28.

[0090] In particular, second variances 15b are determined depending on the second reference data 14b and the second received information 13b. For example, second standard deviations 16b are determined depending on the second variances 15b and the second reference data 14b. Preferably, second deviation values ​​17b are determined depending on the second standard deviations 16b and a second adjustment factor 18b.

[0091] In one embodiment, ratio values ​​19 are determined from the first deviation values ​​17a to the second deviation values ​​17b. For example, a quotient is determined depending on a deviation value of the first deviation values ​​17a and a deviation value of the second deviation values ​​17b. The deviation values ​​17a, 17b are each determined at the same sampling time, for example.

[0092] In one embodiment, angles 20 are determined depending on the ratio values ​​19, an angular gradient 21, and an angular offset 22. The angular gradient 21 and the angular offset 22 are provided, for example, to the evaluation unit 3.

[0093] For example, the angles 20 contain at least one angle cp.

[0094] For example, an angle of the angles 20 can lie in a positive angle range ß1 (Fig. 3) or a negative angle range ß2 (Fig. 3).

[0095] In one embodiment, distances 23 are determined from the received information 13a, 13b. For example, the distances 23 contain at least one distance R. In particular, the distances 23 are generated depending on the respective sampling time of the received information 13a, 13b. Since the received information 13a and the received information 13b are preferably generated at the same time, there is a first piece of received information and a second piece of received information for each sampling time, for which, in particular, a distance is determined in each case.

[0096] In one embodiment, the distances 23 and the angles 20 are converted into Cartesian coordinates x, y. For example, for each coordinate, there is a first deviation value of the first deviation values ​​17a and a second deviation value of the second deviation values ​​17b.

[0097] In this case, one of the subregions 11 is preferably assigned the first deviation value if the associated angle is in the positive angle range ß1. If the associated angle is in the negative angle range ß2, then the second deviation value is assigned to the subregion 11 if necessary. For example, there are first subregions 6a and second subregions 6b of the interior 6, with the first deviation values ​​17a being assigned to the first subregions 6a and the second deviation values ​​17b being assigned to the second subregions 6b. The first subregions 6a are preferably separated from the second subregions 6b by the longitudinal axis 1a.

[0098] In Fig. 3, the at least one deviation value 28 is shown as an example. This is a distance R from the origin 12. The at least one deviation value 28 is located at at least one angle (p) relative to the longitudinal axis 1a. In the exemplary embodiment shown in Fig. 3, the at least one angle (p) is in the positive angular range ß1. In particular, the at least one deviation value is therefore one of the first deviation values ​​17a. For example, a position of the at least one deviation value 28 is determined in Cartesian coordinates x, y. For example, in the exemplary embodiment shown in Fig. 3, the at least one deviation value 28 is located at the position (4 | 2).

[0099] For example, deviation values ​​17a, 17b that are smaller than a specified minimum value are discarded and / or not assigned to any of the sub-areas 11 and / or set to zero.

[0100] In one embodiment, a verification unit 26 checks whether the assigned deviation values ​​17a, 17b are located within the interior space 6 according to their position. In the embodiment shown in Fig. 3, for example, all sub-areas 11 with the coordinates x, y from x = 0 to x = 12 for the transverse extent 8 and y = -5 to y = 5 for the longitudinal extent 9 are located within the interior space 6. For example, the coordinates can be centimeter ranges per sub-area 11.

[0101] In one embodiment, state 27 is determined depending on the position of the deviation values ​​17a, 17b and the deviation values ​​17a, 17b. If one of the deviation values ​​17a, 17b exceeds, for example, a predetermined limit value 25, state 27 is determined to indicate that the occupancy status of the motor vehicle 1 has changed, and the alarm is triggered if necessary.

Claims

Patent claims 1. A method for monitoring an interior (6) for a motor vehicle (1) with at least one ultrasound system (2a), comprising the steps of: a) emitting at least one ultrasound signal by means of an ultrasound transmitter (4) of the ultrasound system (2a); b) providing received information (13a, 13b) generated as a function of the emitted ultrasound signal; c) providing reference data (14a, 14b) representing a past state of the interior (6); d) comparing at least one piece of received information (13a, 13b) of the received information (13a, 13b) with the reference data (14a, 14b) to generate at least one deviation value (17a, 17b, 28); e) determining at least one distance (23, R) of the at least one piece of received information (13a, 13b) from the ultrasound transmitter (4);f) determining at least one angle (20, (p) of the at least one deviation value (17a, 17b, 28) to an axis, in particular a longitudinal axis (1a), of the motor vehicle (1); g) determining a state (27) of the interior (6) as a function of the at least one deviation value (17a, 17b, 28) and as a function of the at least one distance (23, R) and the at least one angle (20, αp); 2. Method according to claim 1, wherein for determining the at least one deviation value (17a, 17b, 28) at least one standard deviation is determined depending on the reference data (14a, 14b) and the at least one piece of received information (13a, 13b).

3. The method according to claim 2, wherein to determine the at least one deviation value (17a, 17b, 28) the at least one standard deviation is multiplied by an adjustment factor (18a, 18b).

4. Method according to one of the preceding claims, wherein, in order to determine the state (27) of the interior (6), it is checked whether the at least one deviation value (17a, 17b, 28) exceeds a limit value (25) and whether the at least one deviation value (17a, 17b, 28) is determined according to the at least one distance (23, R) and the at least one angle (20, <p) im Innenraum (6) liegt.

5. The method according to claim 4, wherein the state (27) of the interior space (6) is a temporary occupancy state of the interior space (6).

6. The method according to claim 5, wherein the occupancy state is assessed as unauthorized if a theft of the motor vehicle (1) or an object from the interior (6) is detected.

7. Method according to one of the preceding claims, wherein the at least one distance (23, R) and the at least one angle (20, <p) in kartesische Koordinaten (x, y, z) umgerechnet wird.

8. The method according to claim 7, wherein a map (10) representing an environment of the motor vehicle (1) and the interior (6) of the motor vehicle (1) is generated, wherein the map (10) is divided into partial areas (11) in a grid-like manner, and a deviation value (17a, 17b, 28) is assigned to several of the partial areas (11) depending on the Cartesian coordinates (x, y, z).

9. Method according to claim 4 and 8, wherein the comparison with the limit value (25) is carried out for each sub-area (11) with the associated deviation value (17a, 17b, 28).

10. Method according to one of the preceding claims, wherein the received information (13a, 13b) contains first received information (13a) and second received information (13b) and the reference data (14a, 14b) contains first reference data (14a) and second reference data (14b), wherein at least a first received information (13a) of the first received information (13a) is compared with the first reference data (14a) to generate at least one first deviation value (17a) and a second received information (13b) of the second received information (13b) is compared with the second reference data (14b) to generate Generation of at least one second deviation value (17b), wherein the first reception information (13a) is generated by a first ultrasound receiver (5a) of the ultrasound system (2a) depending on the emitted ultrasound signal and the second reception information (13b) is generated by a second ultrasound receiver (5b) of the ultrasound system (2a) depending on the emitted ultrasound signal.

11. Method according to claim 10, wherein the at least one angle (20, (p) is determined as a function of a quotient of the at least one first deviation value (17a) and the at least one second deviation value (17b).

12. Method according to claim 8 and one of claims 10 to 11, wherein the sub-areas (11) are divided into first sub-areas (6a) and second sub-areas (6b) and first deviation values ​​(17a) are assigned to the first sub-areas (6a) and second deviation values ​​(17b) are assigned to the second sub-areas (6b).

13. Method according to one of the preceding claims, wherein the ultrasound system (2a) is arranged on a vehicle roof.

14. The method according to claim 13, wherein the ultrasonic transmitter (4) transmits the ultrasonic signal with a main transmission direction in the direction of a center console of the motor vehicle (1).

15. Interior monitoring device (2) for a motor vehicle (1), comprising at least one ultrasound system (2a) with an ultrasound transmitter (4), an ultrasound receiver (5a, 5b) and an evaluation unit (3), wherein the interior monitoring device (2) is designed to carry out a method according to one of the preceding claims.

16. Motor vehicle (1) with an interior monitoring device (2) according to claim 15.

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