Restraint system for a motor vehicle, motor vehicle and method for operating such a restraint system

Abstract

The invention relates to a restraint system (1) for a motor vehicle, comprising at least one safety belt (5) which is provided with at least two markers (7) for reflecting electromagnetic radiation, comprising at least one sensor device (8) by means of which the electromagnetic radiation reflected by the markers (7) can be detected, and comprising an electronic computing device (10) by means of which a position (P) of the safety belt (5) can be determined as a function of the electromagnetic radiation detected by the sensor device (8) and reflected by the markers (7), wherein the markers (7) differ from one another in their shapes.

Description

[0001] The invention relates to a restraint system for a motor vehicle, in particular for a passenger car, according to the preamble of patent claims 1 and 6. The invention also relates to a motor vehicle. Furthermore, the invention relates to a method for operating such a restraint system.

[0002] DE 10 2018 207 977 B4 discloses a driver assistance system for a vehicle. DE 10 215 120 811 B4 discloses a method for detecting a seat belt position in a vehicle. Furthermore, DE 101 33 759 C2 discloses a device for detecting an object or person in the interior of a vehicle.

[0003] The object of the present invention is to provide a restraint system for a motor vehicle, a motor vehicle and a method for operating such a restraint system, so that a particularly high level of safety can be achieved.

[0004] This object is achieved according to the invention by a restraint system having the features of patent claim 1, by a restraint system having the features of patent claim 6, by a motor vehicle having the features of patent claim 9, and by a method having the features of personal claim 10. Advantageous embodiments of the invention are the subject of the dependent claims.

[0005] A first aspect of the invention relates to a restraint system for a simple motor vehicle, also referred to as a vehicle and preferably designed as a passenger car, the interior of which, also referred to as a passenger cell or passenger compartment, is formed by a structure of the motor vehicle, designed, for example, as a self-supporting body. The restraint system has at least one safety belt for restraining an occupant, in particular, who is located in the interior. For example, the safety belt is assigned to a seat arranged in the interior. The seat is provided, for example, by a seating system. The seating system is arranged in the interior. The seating system can be an individual seat, also referred to as a vehicle seat, which provides the seat as the only seat, or the seating system can be a bench seat, designed, for example, as a rear bench.In particular, the safety belt has, for example, a particularly flexible, i.e. shape-unstable belt strap and, for example, a tongue, which is also referred to as a belt tongue and is connected to the belt strap.

[0006] For example, the seat belt includes a buckle that is at least indirectly attached to the body. For example, the tongue can be inserted into the buckle and thereby connected, particularly in a form-fitting manner, to the buckle, so that the belt webbing can be coupled to the belt buckle via the tongue. This allows, for example, the seat occupant to fasten the seat belt, which can then restrain the occupant, for example, in the event of a frontal collision with the vehicle.

[0007] The seat belt, in particular the belt webbing, is provided with at least two markers for reflecting electromagnetic radiation. This means that the markers are designed to reflect electromagnetic radiation. Electromagnetic radiation is also referred to as electromagnetic waves or is formed by electromagnetic waves or comprises electromagnetic waves.

[0008] The restraint system also has at least one sensor device, by means of which the electromagnetic radiation reflected by the markers can be detected. The restraint system also comprises an electronic computing device, by means of which at least one position of the seat belt can be determined depending on the electromagnetic beam detected by the sensor device and reflected by the markers. For example, the sensor device can provide at least one sensor signal, in particular an electrical one, wherein, for example, the electronic computing device can receive the sensor signal. The transmitter signal characterizes the electromagnetic radiation detected by the sensor device, which is also referred to simply as radiation or simply as waves.As a result, the electronic computing device can determine the position of the safety belt, in particular in relation to the occupant sitting on the seat, depending on the received sensor signal and thus depending on the radiation detected by the sensor device.

[0009] In order to be able to achieve a particularly high level of safety, the invention provides that the markers differ in their shapes from one another. This means that the markers have different shapes. In other words, a first of the markers has a first shape, whereas a second of the markers has a second shape that is different from the first. This allows the position of the seat belt to be determined particularly precisely. As a result, it is possible, for example, to determine particularly precisely, safely and meaningfully whether the determined position is a desired reference position. In other words, it is possible, for example, to determine particularly precisely, safely and meaningfully whether the occupant has fastened the seat belt correctly, i.e. as desired, or whether the position is unfavorable.position or even whether the tongue has been inserted into the belt buckle but the occupant has not fastened the seat belt correctly or not at all, but for example the seat belt is located between the occupant and the seat system. As a result, it is possible, for example, to operate the motor vehicle depending on the determined position, in particular in such a way that at least one function of the motor vehicle is carried out depending on the determined position of the seat belt. The function comprises, for example, that, in particular in the interior, an information signal which can be perceived visually and / or acoustically and / or haptically by a person located in the interior is output, for example by means of an electrical and electronic playback device in the motor vehicle. The person is, for example, the aforementioned occupant.The warning signal can, for example, alert the person that the detected position is unfavorable, particularly with regard to restraining the person. In particular, the warning signal can encourage the person to fasten their seatbelt correctly, for example, in order to effectively restrain the person or passenger in the event of a frontal collision.

[0010] The position of the seat belt that can be determined by the electronic computing device is, for example, a spatial position of the seat belt, i.e., a position, orientation, or orientation of the seat belt within the vehicle interior. In particular, the position of the seat belt in relation to the occupant can be determined, allowing, for example, a precise determination of whether the occupant has correctly fastened their seat belt or not.

[0011] The sensor device is or comprises, for example, at least one camera, by means of which, for example, an image of at least a partial area of ​​the interior can be captured. In particular, the camera is designed, for example, to capture the radiation reflected by the markers and thereby capture an image of the markers. The electronic computing device can, for example, analyze the image and, by analyzing the image, determine a respective marker position of the markers, in particular in the interior, and subsequently the position of the seat belt.

[0012] Depending on the determined position, a restraining force intended to restrain the occupant can be adjusted, i.e., varied. The restraining force is designed or configured to restrain the occupant, for example, in the event of an accident-related force application, particularly resulting from a frontal impact of the motor vehicle. As a result, it is possible to restrain the occupant particularly well while avoiding excessive stress on the occupant resulting from the restraint.

[0013] In particular, determining the position of the seat belt may, for example, involve determining the extended length of the seat belt, in particular the belt strap. The extended length is understood to be the length of the belt strap, with the belt strap being unwound by the length from a belt reel.

[0014] In order to be able to determine the position of the seat belt particularly precisely, one embodiment of the first aspect of the invention provides that the markers are infrared markers and are thus designed, in particular, to reflect exclusively infrared radiation rather than electromagnetic radiation. Infrared radiation is understood to mean, in particular, electromagnetic waves with a frequency of 300 GHz to 384 THz or 400 THz.

[0015] In order to be able to advantageously determine the position of the seat belt, especially in poor lighting conditions in the interior, a further embodiment of the invention provides that the restraint system has at least one light source, which is designed, in particular, to emit only infrared radiation and, in particular, to radiate it into the interior. The light source is or comprises, for example, at least one or more light-emitting diodes (LEDs), which, in particular, emit only infrared radiation and, in particular, can radiate it into the interior.

[0016] A further embodiment of the first aspect of the invention is characterized in that the markers are radar markers and are thus designed, in particular exclusively or solely, to reflect radar radiation, i.e., radar waves, rather than electromagnetic radiation. Radar radiation, also referred to as radar waves, refers to radar waves or electromagnetic waves with a frequency of 300 GHz or less, in particular with a frequency of 30 kHz to 300 GHz. This allows the position of the seat belt to be determined particularly precisely.

[0017] In order to be able to determine the position of the safety belt precisely, in particular even in unfavorable lighting conditions in the interior, it is provided in a further embodiment of the first aspect of the invention that the sensor device has at least one radar sensor which is designed, in particular only or exclusively, to emit radar radiation and to detect the radar radiation as the electromagnetic radiation.

[0018] A second aspect of the invention relates to a restraint system for a motor vehicle, also simply referred to as a vehicle and preferably designed as a passenger car. The restraint system according to the second aspect of the invention has at least one safety belt, which is provided with at least one marker, in particular for reflecting electromagnetic radiation. The restraint system according to the second aspect of the invention also has at least one sensor device by means of which reflected electromagnetic radiation, which is simply referred to as radiation or waves, can be detected. In particular, the sensor device in the second aspect is designed to detect the electromagnetic radiation reflected by the marker, which is simply referred to as radiation or waves.The second aspect of the invention also provides for an electronic computing device, also referred to as a control device or designed as a control device, by means of which a position of the safety belt can be determined as a function of the electromagnetic radiation detected by the sensor device and, for example, reflected by the marker.

[0019] In order to be able to detect the position of the seat belt particularly precisely and reliably and consequently enable a high level of safety, since, for example, depending on the determined position, an occupant sitting in a seat to which the seat belt belongs can be particularly advantageously restrained by means of the seat belt, the second aspect of the invention provides that the marker is a radar marker and is therefore designed, in particular exclusively or only, to reflect or absorb radar radiation, thus radar waves as the electromagnetic radiation. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention and vice versa. The radar marker of the second aspect of the invention is also referred to as the first radar marker.As already explained in relation to the first aspect of the invention, radar radiation in the context of the present disclosure is understood to mean radar waves or electromagnetic waves with a frequency of 300 GHz and less, in particular with a frequency of 30 kHz to 300 GHz.

[0020] For example, according to the second aspect of the invention, the safety belt, in particular belt webbing, is provided with at least two markers, namely the first radar marker and at least one second radar marker provided in addition to the first radar marker. The previous and following statements regarding the first radar marker can be readily applied to the second radar marker and vice versa. For example, according to the second aspect of the invention, the markers differ from one another in their shapes.

[0021] Preferably, the markers with which the seat belt is provided are spaced apart from each other, particularly completely. This allows the position of the seat belt to be determined particularly advantageously.

[0022] In order to be able to determine the position of the seat belt particularly advantageously and consequently achieve particularly advantageous restraint of the occupant, it is provided in an advantageous embodiment of the first aspect and the second aspect of the invention that the sensor device is designed to capture at least one image of the occupant. The electronic computing device is preferably designed to analyze the image and, by analyzing the image, to determine at least one property of at least part of a body of the occupant. The property is, for example, a size of at least part of the body. In particular, the property can be the size of the occupant's body as a whole, also referred to as body size.Furthermore, the property can alternatively or additionally be or include, for example, a weight of at least part of the body, in particular a weight of the body, also referred to as body weight, and thus of the occupant as a whole. Alternatively or additionally, the property can be or include, for example, at least one, in particular, external shape of at least part of the body, in particular of the body as a whole.

[0023] Furthermore, the electronic computing device is preferably designed to compare the determined position as the actual position with a target position assigned to the determined property. In other words, the electronic computing device is preferably designed to compare the actual position with the target position. As a result, it is possible, for example, to operate the motor vehicle depending on the comparison of the actual position with the target position. Thus, for example, the aforementioned function of the motor vehicle can be carried out depending on the comparison of the actual position with the target position. For example, the target position and the aforementioned reference position are involved. In particular, it is possible to adjust, i.e., vary, the aforementioned restraining force depending on the comparison of the actual position with the target position.It is therefore possible, for example, to issue the aforementioned warning signal, particularly in the interior, based on a comparison of the actual position with the target position. If, for example, the actual position corresponds to the target position, it can be concluded that the occupant has fastened their seat belt correctly. As a result, the occupant can be advantageously restrained and thus protected by the seat belt, for example in the event of a head-on collision. However, if the comparison shows that the actual position deviates from the target position, it can then be concluded that the person, i.e. the occupant, has not fastened the seat belt or has not fastened it correctly, which may have a detrimental effect on the restraint of the occupant.As a result, the occupant can be alerted, for example, by means of an alert signal that the actual position deviates undesirably from the target position. In particular, the alert signal can encourage the occupant to fasten their seatbelt so that the actual position corresponds to the target position.

[0024] Finally, it has proven particularly advantageous for achieving a particularly high level of safety if the electronic computing device is designed to provide, depending on the comparison of the actual position and the target position, at least one signal—also referred to as a control signal or actuation signal and embodied, for example, as an electrical signal—for effecting the aforementioned function of the motor vehicle. This allows, for example, the motor vehicle to be operated depending on the determined position, in particular depending on the comparison of the actual position with the target position, thereby ensuring a particularly high level of safety.

[0025] A third aspect of the invention relates to a motor vehicle, also simply referred to as a vehicle, which is preferably designed as a passenger car. The motor vehicle has at least one restraint system according to the first aspect of the invention and / or according to the second aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention and the second aspect of the invention are to be considered the advantages and advantageous embodiments of the third aspect of the invention, and vice versa.

[0026] A fourth aspect of the invention relates to a method for operating a restraint system according to the first aspect and / or the second aspect of the invention. Advantages and advantageous embodiments of the first aspect, the second aspect, and the third aspect of the invention are to be considered the advantages and advantageous embodiments of the fourth aspect of the invention, and vice versa.

[0027] The respective marker is, for example, woven into the belt webbing. At least part of the sensor device, in particular at least one sensor for detecting the reflected electromagnetic radiation, is arranged, for example, on a roof liner that defines the upper boundary of the interior of the motor vehicle in the vertical direction. Determining the position includes, for example, determining the extent of the seat belt, in particular the belt webbing, also referred to as the course.If, for example, it is determined based on the determined positions, in particular by comparing the actual position with the target position, that the seat belt is, for example, covered by the occupant's shoulder in one of their shoulder areas and thus runs too far back in the vehicle's longitudinal direction compared to the target position, it can then be concluded that the occupant has not fastened the seat belt correctly and, for example, the seat belt is running under one of the occupant's arms. If, for example, the restraint force is adjusted depending on the determined position, this can achieve adaptive restraint of the occupant, particularly in the event of an accident. For example, a fifth percentile person, in particular a fifth percentile woman, can be separated or differentiated from a 50th percentile person, in particular a 50th percentile man.Furthermore, plausibility checks are possible. Based on the position, especially the course, it can be checked, for example, whether the determined characteristic, in particular the determined height and weight, matches a particular person class.

[0028] In particular, it is conceivable that the position of the seat belt could be detected as a three-dimensional position or orientation, also referred to as a 3D position, particularly in the interior. This allows the position of the seat belt to be advantageously determined, particularly in relation to the occupant or body.

[0029] In a further embodiment of the invention, it is possible to perform seat occupancy detection based on the aforementioned image. For example, the image of the interior can be used to determine whether the seat is occupied by a passenger or not.

[0030] In particular, when the marker is designed as the aforementioned radar marker, the marker is formed, for example, from a metallic material. It is conceivable that the marker is formed from fibers made of the metallic material, which can be woven, for example, into the seat belt, in particular into the belt webbing. It is conceivable, particularly when the marker is designed as a radar marker, that the marker is formed from a material with high permittivity. For example, the material is a semiconductor material. It is possible for the marker to be formed from a plastic that reflects radar radiation.

[0031] Preferably, the respective marker itself, considered on its own, is flexible, i.e., dimensionally unstable, particularly like the belt webbing, so that a high level of wearing comfort of the seat belt, also referred to as belt comfort, can be ensured. The radar marker is formed, for example, from a metal foil, which may be made of aluminum, for example. Furthermore, the radar marker can be formed by a plastic structure, in particular one with a metallic coating. In other words, it is conceivable for the radar marker to have a plastic structure, in particular as a base body, which is provided, for example, with a metallic coating. Furthermore, it is conceivable for the marker, in particular the radar marker, to be a radar-absorbing marker, and thus a marker that absorbs radar radiation, so that, for example, the marker is formed from a radar-absorbing material, i.e., from a material that absorbs radar radiation.The marker can be formed, for example, from a carbon-containing structure. In summary, it is therefore preferable for the radar marker to have a significantly higher or lower reflectivity for radar radiation than the occupant, in order to advantageously generate the aforementioned image, for example, through the resulting contrast.

[0032] The sensor device, in particular the radar sensor, has, for example, at least or exactly 48 transmission channels and at least or exactly 48 reception channels. For example, the sensor device, in particular the radar sensor, has a base bandwidth of 4 GHz, so that reflected radar radiation can be advantageously detected by the sensor device. In particular, at least or exactly five seats present in the interior and associated seat belts can be detected and / or monitored. The marker, which is designed in particular as a radar marker, is made, for example, of aluminum, in particular of aluminum foil. This advantageously allows the position of the seat belt to be determined.

[0033] Further details of the invention will become apparent from the following description of preferred embodiments with the accompanying drawings. In the drawings: Fig. 1 is a schematic representation of a first embodiment of a restraint system for a motor vehicle; and Fig. 2 a schematic representation of a second embodiment of the restraint system.

[0034] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0035] Fig. Figure 1 shows a schematic representation of a first embodiment of a restraint system 1 for a simple motor vehicle, referred to as a vehicle, whose interior 2, also referred to as a passenger cell or passenger compartment, is formed by a structure preferably designed as a self-supporting body. At least one seat 3 for a person 4, also referred to as an occupant, is arranged in the interior 2, wherein the seat 3 is provided by a seating system arranged in the interior 2 of the passenger vehicle. As can be seen from Fig. 1 is that, for example, the occupant, i.e., person 4, is sitting on seat 3. The restraint system 1 has a safety belt 5 assigned to seat 3, by means of which, particularly when the person 4 has correctly fastened the safety belt 5, the person 4 can be advantageously restrained, for example, in the event of a frontal collision with the motor vehicle. The safety belt 5 has a belt webbing 6, which, viewed on its own, is pliable, i.e., unstable in shape.

[0036] In the Fig. In the first embodiment of the restraint system 1 shown in Figure 1, the belt webbing 6 and thus the safety belt 5 are provided with a plurality of markers 7, which are arranged in pairs completely spaced from one another and, in particular, one after the other in the longitudinal direction of the belt webbing 6. The respective marker 7 is designed to reflect electromagnetic radiation, i.e., electromagnetic waves. The restraint system 1 has a sensor device 8, by means of which the electromagnetic radiation reflected by the markers 7 can be detected. In a method for operating the restraint system 1, the electromagnetic radiation reflected by the markers 7 is detected by means of the sensor device 8. For this purpose, the sensor device 8 is or comprises, for example, a camera 9, by means of which, for example, an image of at least a partial area of ​​the interior 2 can be or is detected.The seat belt 5 can be arranged or is arranged in the partial area such that, for example, at least one image of the seat belt 5 and, in this case, the marker 7 can be captured or is captured by the sensor device 8, in particular by the camera 9, in particular by the sensor device 8, in particular the camera 9, capturing the electromagnetic radiation reflected by the markers 7. In other words, the electromagnetic radiation reflected by the markers 7, for example, forms the aforementioned image.

[0037] The restraint system 1 also has a Fig. 1 has an electronic computing device 10, which is shown particularly schematically, by means of which a position of the safety belt 5, in particular of the belt webbing 6, is determined, in particular calculated, depending on the electromagnetic radiation detected by the sensor device 8 and reflected by the markers 7. The determined position is shown in Fig. 1 and designated by P. In particular, the determined position P is or comprises a course of the safety belt 5, in particular of the belt webbing 6, in particular in the interior 2. For example, a computational model, also simply referred to as a model, is provided, which is stored, for example, in a data memory, in particular an electronic data memory, of the electronic computing device 10. By means of the model, the electronic computing device 10 determines, in particular calculates, for example, the position P, which is in particular a spatial and thus three-dimensional position of the safety belt 5, in particular of the belt webbing 6, in the interior 2, as a function of the image and thus the dependence on the electromagnetic radiation reflected by the markers 7.Furthermore, the electronic computing device 10 determines, in particular calculates, for example, in particular by means of the model and preferably as a function of the aforementioned image of the interior, at least one property of the occupant, in particular of their body 11. In other words, the property of the occupant is, for example, a property of the body 11 of the occupant. The property is or includes, for example, a particular external shape and / or a weight and / or a size of initially a part of the body 11, in particular of the body 11 as a whole. For example, a target position is assigned to the determined property, which is stored, for example, in the data memory. It is conceivable that the electronic computing device 10 compares the determined position P as the actual position with the target position assigned to the property.If, for example, the actual position corresponds to the target position, it can be concluded that person 4 has correctly fastened the seat belt 5, so that person 4 can subsequently be advantageously restrained by the seat belt 5. However, if the actual position deviates from the target position, it can be concluded that the occupant (person 4) has not fastened the seat belt 5 or has not fastened it correctly, which can be disadvantageous for restraining person 4 in the event of an accident.

[0038] For example, the electronic computing device 10 can, depending on the determined position P, in particular depending on the comparison of the actual position with the target position, provide at least one signal, in particular an electrical signal, by means of which, for example, at least one function of the motor vehicle can be effected or is effected. Thus, for example, the motor vehicle can be operated depending on the determined position P, in particular depending on the comparison of the actual position with the target position. The function comprises, for example, that at least one information signal that can be perceived visually and / or haptically and / or acoustically by the person 4 is output in the interior 2, in particular by means of an in particular electrical or electronic playback device of the motor vehicle. The information signal can, for example, encourage the person 4 to fasten the seat belt 5 correctly.

[0039] In order to be able to determine the position P particularly precisely, the first embodiment provides for the markers 7, particularly in pairs, to differ in their shapes. It can be seen that, for example, a first of the markers 7 is star-shaped. A second of the markers 7 is triangular, for example. A third of the markers 7 is square, for example, and is diamond-shaped, for example. A fourth of the markers 7 is pentagonal, for example, in particular as a pentagon and most particularly as an equilateral pentagon.

[0040] Fig. 2 shows a second embodiment of the restraint system 1. In the second embodiment, the safety belt 5, in particular the belt webbing 6, is also provided with a plurality of markers 7, which are spaced apart from one another, in particular in pairs, in particular completely spaced apart from one another. In the second embodiment, for example, subregions of the belt webbing 6, which is provided with the markers 7 in the subregions, have different numbers and thus different densities of the markers 7 arranged in the subregions. This means that, for example, the respective subregions differ from one another in the respective number of markers 7 arranged in the subregions.

[0041] In the first embodiment, the respective marker 7 is configured, for example, as an infrared marker and is thus designed, in particular, to reflect only infrared radiation as the electromagnetic radiation. Infrared radiation is understood to mean electromagnetic waves with a frequency of 300 GHz to 384 THz or 400 THz.

[0042] In the second embodiment, the sensor device 8 is also designed to receive, i.e., detect, reflected electromagnetic radiation. In the second embodiment, the Fig. 2, the electronic computing device 10, not shown, is designed to determine, in particular to calculate, the position P of the safety belt 5 as a function of the electromagnetic radiation detected by the sensor device 8 and reflected by the markers 7, for example with the aid of the aforementioned computing model.

[0043] In the second embodiment, however, the respective marker 7 is designed as a respective radar marker and is thus designed, in particular only or exclusively, to reflect or absorb radar radiation as the electromagnetic radiation. Fig.In the second embodiment shown in Figure 2, it is provided that the respective marker 7 is designed as a respective radar marker and is therefore configured, in particular exclusively or only, to reflect radar radiation as the electromagnetic radiation. The radar radiation is intended to reflect radar waves, thus electromagnetic waves with a frequency of 300 GHz and less, in particular with a frequency of 30 kHz to 300 GHz. For this purpose, for example, in the second embodiment, the respective marker 7 is formed from a metallic material, in particular from aluminum, wherein, for example, the respective marker 7 is formed from a respective metallic foil, in particular from a respective aluminum foil.In the respective sub-region in which several of the markers 7 are arranged, the plurality of markers 7 arranged in the respective sub-region are aligned parallel to one another, in particular with regard to their respective longitudinal extension directions, so that, for example, in the respective sub-region in which several of the markers 7 are arranged, the longitudinal extension directions of the plurality of markers 7 arranged in the respective sub-region run parallel to one another. It can be seen that in a first of the sub-regions exactly one of the markers 7 is arranged, in a second of the sub-regions exactly two of the markers 7 are arranged, in a third of the sub-regions exactly three of the markers 7 are arranged, and in a fourth of the sub-regions exactly four of the markers 7 are arranged.In this case, it is preferably provided that in the second sub-region, in the third sub-region, and in the fourth sub-region, the respective markers 7 are arranged relative to one another in such a way that the longitudinal extension directions of the markers 7, particularly when viewed in pairs, run parallel to one another. As a result, the plurality of markers 7 arranged in the respective sub-region form a respective structure that reflects radar radiation.

[0044] In the second embodiment, the sensor device 8 is or comprises, for example, at least one radar sensor which, for example, can detect the position P, in particular as a three-dimensional position in the interior 2, by detecting the radar radiation reflected by the markers 7 and by distance and angle measurements, so that the position P, in particular as a three-dimensional position in the interior, can be determined by the electronic computing device 10. In the second embodiment, the respective marker 7 is designed as a respective reflection strip which can reflect radar beams. Due to the aforementioned differences in the number and, in particular, spacing of the markers 7, the position P of the, in particular, complete belt webbing 6 can be advantageously detected.

[0045] Connected to the belt webbing 6 is, for example, a plug-in tongue of the safety belt 5, which is formed separately from the belt webbing 6 and is also referred to as a belt tongue. The safety belt 5 has, for example, a belt buckle which is at least indirectly connected to the body, into which the belt tongue can be inserted in order to thereby connect the belt tongue, in particular in a form-fitting manner, and via the belt tongue the belt webbing 6 to the belt buckle and therefore to the body.If, for example, it is detected, in particular by means of a plug-in sensor designed as a Hall sensor, that the tongue is inserted into the belt buckle, and if it is determined by means of the sensor device 8 and the electronic computing device 10 that the person 4 has not fastened the seat belt 5, which is determined, for example, by the belt webbing 6 not being detected by the sensor device 8, then it is concluded, for example, that the person 4 has not fastened the seat belt 5 correctly or has not fastened it at all. As a result, for example, the aforementioned information signal is output, in particular as a warning signal in the interior 2. The information signal encourages the person, for example, to fasten the seat belt 5 correctly. In this way, a high level of safety can be guaranteed. List of reference symbols 1 restraint system 2 Interior 3 seats 4 people 5 Seat belt 6 webbing 7 markers 8 Sensor device 9 Camera 10 electronic computing device 11 bodies P Position QUOTES CONTAINED IN THE DESCRIPTION

[0000] 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

[0000] DE 10 2018 207 977 B4

[0002] DE 10 215 120 811 B4

[0002] DE 101 33 759 C2

[0002]

Claims

[1] Restraint system (1) for a motor vehicle, comprising at least one safety belt (5) which is provided with at least two markers (7) for reflecting electromagnetic radiation, comprising at least one sensor device (8) by means of which the electromagnetic radiation reflected by the markers (7) can be detected, and comprising an electronic computing device (10) by means of which a position (P) of the safety belt (5) can be determined as a function of the electromagnetic radiation detected by the sensor device (8) and reflected by the markers (7), characterized by that the markers (7) differ in their shapes. [2] Restraint system (1) according to claim 1, characterized by that the markers (7) are designed as infrared markers and are therefore designed to reflect infrared radiation as the electromagnetic radiation. [3] Restraint system (1) according to claim 2, characterized bythat the restraint system (1) has at least one light source which is designed to emit infrared radiation. [4] Restraint system (1) according to claim 1, characterized by that the markers (7) are designed as radar markers and are therefore designed to reflect radar radiation as the electromagnetic radiation. [5] Restraint system (1) according to claim 4, characterized by that the sensor device (8) has at least one radar sensor which is designed to emit radar radiation and to detect the radar radiation as the electromagnetic radiation. [6] Restraint system (1) for a motor vehicle, comprising at least one safety belt (5) which is provided with at least one marker (7), comprising at least one sensor device (8) by means of which reflected electromagnetic radiation can be detected, and comprising an electronic computing device (10) by means of which a position (P) of the safety belt (5) can be determined as a function of the electromagnetic radiation detected and reflected by the sensor device (8), characterized by that the marker (7) is designed as a radar marker and is thereby designed to reflect or absorb radar radiation as the electromagnetic radiation. [7] Restraint system (1) according to one of the preceding claims, characterized by , that: - the sensor device (8) is designed to capture at least one image of an occupant (4) sitting on a seat to which the safety belt (5) is assigned; - the electronic computing device (10) is designed to analyze the image and, by analyzing the image, to determine at least one property of at least one part of a body (11) of the occupant (4); and - the electronic computing device (10) is designed to compare the determined position (P) as an actual position with a target position associated with the determined property. [8] Restraint system (1) according to claim 7, characterized by that the electronic computing device (10) is designed to provide at least one signal for effecting at least one function of the motor vehicle depending on the comparison of the actual position with the desired position. [9] Motor vehicle, with at least one restraint system (1) according to one of the preceding claims. [10] Method for operating a restraint system (1) according to one of claims 1 to 8.

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