Vehicle driver monitoring order

Abstract

The invention relates to a vehicle driver monitoring arrangement (10) for monitoring the breathing of a vehicle driver (100) sitting in a driver's seat (20) and wearing a seatbelt, with a safety belt (24) assigned to the driver's seat (20), the belt body (25) of which has a radar reflector (32, 33) which, when the safety belt (24) is fastened by the vehicle operator (100), is arranged on a chest belt section (241) and / or a pelvic belt section (242), a radar detector (30) directed at the driver's seat (20), which detects the radar signals reflected by the radar reflector (32, 33) of the seat belt (24) worn by the vehicle driver, and an electronic breathing monitoring system (40) which is informationally connected to the radar detector (30) which determines the breathing rate (f) of the vehicle operator (100) from the signals received by the radar detector (30) and which outputs a warning signal (w) when the breathing rate falls below a limit frequency (flimit) stored in a limit frequency memory (42).

Description

[0001] The invention relates to a vehicle driver monitoring arrangement for the continuous monitoring of the breathing of a vehicle driver sitting in a driver's seat and secured with a safety belt.

[0002] For semi-autonomous and autonomous driving of a vehicle in public spaces, continuous monitoring of the driver's health is required. In addition to monitoring heart activity, this includes, alternatively or additionally, monitoring the driver's respiration. DE 10 2021 100 576 A1 discloses the monitoring of a driver's respiration using a sensor attached to the driver's chest. However, the application of the sensor is cumbersome, unreliable, and problematic in terms of its acceptance.

[0003] Against this background, the object of the invention is to create a vehicle driver monitoring arrangement with convenient monitoring of the breathing of a vehicle driver sitting in a driver's seat.

[0004] This problem is solved according to the invention with a vehicle driver monitoring arrangement having the features of claim 1.

[0005] The vehicle driver monitoring device according to the invention serves for the continuous, non-contact monitoring of the breathing of a vehicle driver seated in a driver's seat and secured with a seat belt. The monitoring device includes a seat belt associated with the driver's seat, the belt body of which has a radar reflector. When the vehicle driver fastens the seat belt, the radar reflector is positioned on a chest section and / or a lap section of the belt so that it is visible to a radar detector. The radar reflector is thus located on the distal side of the seat belt facing away from the vehicle driver's body, or is visible to the radar detector from the side of the seat belt facing away from the vehicle driver.

[0006] The radar reflector can be rigid, or alternatively, it can consist of a multitude of small, rigid reflector elements. Alternatively, and preferably, it can be made of a flexible material exhibiting a high specific radar signature. The specific radar signature is at least three times larger than the radar signature of the reflector-free belt body of the seat belt.

[0007] The radar detector is preferably mounted on the vehicle, but can alternatively be mounted on the seat. The radar detector is directed towards the driver's seat or the person operating the vehicle while seated in the driver's seat and, under normal circumstances, sees the radar reflector with essentially no shadows or very little shadow. The radar detector detects the electromagnetic radiation emitted by the radar detector and reflected by the radar reflector. The radar detector determines the distance between the radar reflector and the radar detector at frequent intervals, for example, several times per second, and with an accuracy of at least one millimeter.

[0008] The radar detector is connected via a signal link to an electronic breathing monitor, which determines the driver's breathing rate from the distance signals received by the radar detector. As soon as the driver's measured breathing rate falls below a threshold stored in a frequency memory, the breathing monitor issues a warning signal. This threshold can be, for example, a few Hertz or as low as 5 Hz. The warning signal can be processed in various ways; for instance, it can first trigger an audible warning signal or bring an autonomous vehicle to a controlled and safe stop.

[0009] In automatic seat belts, which are installed in almost all motor vehicles, the belt body lies directly against the body of the buckled-up driver. The breathing rate is typically between 10 and 60 Hertz, meaning the driver's breathing movements are so slow that the belt body largely follows them. The belt body is usually made of a textile fabric optimized for restraint and which does not have a strong radar signature. By applying a radar reflector to the seat belt, the belt, and thus the driver's breathing movements, are made clearly visible to radar detectors. The radar reflector is generally a separate element, but it can also be integrated into the belt body, for example, by being woven in as radar-opaque, flexible threads.

[0010] Textile clothing worn by the vehicle driver, covering the distal end of the radar detector, is permeable to electromagnetic radar waves and therefore poses no problem for its function, meaning that the present monitoring arrangement has a high degree of everyday usability.

[0011] In this way, the breathability of the strapped-in vehicle driver can be continuously monitored in a simple, contactless manner.

[0012] Preferably, the radar detector is operated in a CW mode. While this continuous-wave (CW) mode does not determine the absolute distance between the radar reflector and the radar detector, it does record any changes in distance with high frequency and precision. This is generally sufficient for respiratory monitoring, as the absolute distance between the radar reflector and the radar detector is of secondary importance for determining the breathing-related movements of the driver's body.

[0013] The radar detector is preferably switched between CW and FMCW (Frequency-Modulated Continuous-Wave) operating modes several times per second. This allows for the determination of both the relative movements of the radar reflector and the temporal evolution of its absolute distance from the radar detector. In this way, the respiration rate is recorded and calculated with high redundancy.

[0014] Preferably, the radar reflector is attached to the lap belt section of the seat belt. The lap belt section is suitable for determining breathing patterns because it is positioned relatively independently of the driver's physique and is relatively well-defined in the pelvic and abdominal area of ​​the buckled driver, since the end of the lap belt section, which is fixed to the vehicle or seat, does not roll up or down. Furthermore, breathing movements are comparatively intense in the pelvic area.

[0015] Preferably, the safety belt is designed as a three-point belt with a buckle that is slidably mounted on the belt body. When the safety belt is fastened and closed, the buckle forms the pivot point between the chest belt section and the lap belt section. The belt body has a buckle stopper that the buckle cannot pass. When the safety belt is not in use and is partially retracted, the buckle stopper prevents the buckle from sliding arbitrarily far down into the lap belt section. The buckle stopper is positioned on the belt body of the safety belt such that it is always located between the buckle and the radar reflector of the lap belt section, so that the buckle cannot reach, cover, or damage the radar reflector.

[0016] Alternatively or additionally, it may be provided that the radar reflector assigned to the pelvic belt section is also arranged in a slidable manner on the pelvic belt section and is connected to the belt buckle by a sliding connection, so that the distance between the belt buckle and the radar reflector always remains the same.

[0017] Preferably, a steering sensor is assigned to the vehicle's steering wheel and connected to the electronic respiratory monitoring system via a signal link. The respiratory monitoring system incorporates the steering signal from the steering sensor into its calculation of the respiratory rate. Manual steering movements, particularly in the abdominal area of ​​the driver, can cause interference with the respiratory rate measurement. During significant steering movements, the respiratory rate monitoring can be temporarily suspended to prevent interference and false alarms.

[0018] An embodiment of the invention will be explained in more detail below with reference to the drawings. The drawings show: Fig. 1 schematically a vehicle driver monitoring arrangement for monitoring the breathing of a vehicle driver sitting in a driver's seat and secured with a seat belt in side view, and Fig. 2. The vehicle driver monitoring order of the Fig. 1 in front view.

[0019] The figures depict a motor vehicle 11 with a driver's seat 20 in which a driver 100 is seated. The driver's seat 20 is equipped with an automatic three-point seat belt 24, formed by a belt body 25, the lower end of which is held at a vehicle-mounted attachment point 14 and the other end of which is held at a vehicle-mounted belt retractor 13. The figures show the seat belt 24 fastened, so that the driver 100 is buckled up. The seat belt 24 is formed by a textile belt body 25 with a very small specific radar signature.

[0020] With the driver 100 wearing a seatbelt, the belt body 25 of the safety belt 24 is divided into a chest belt section 241 and a lap belt section 242. A belt buckle 28, which is releasably engaged in a fixed buckle 18, is arranged between the two belt sections 241, 242. The belt buckle 28 is generally arranged to be slidable on the belt body 25.

[0021] The chest belt section 241 runs diagonally across the torso of the vehicle operator 100, whereas the pelvic belt section 242 runs approximately horizontally across the pelvis or abdomen of the vehicle operator 100, as shown in the Fig.Figure 2 shows that two flexible radar reflectors 32, 33 are fixed to the belt body 25: one radar reflector 33 approximately in the center of the lap belt section 242 and another radar reflector 32 in the lower part of the chest belt section 241. Both radar reflectors 32, 33 are positioned distal to the vehicle operator 100, i.e., on the distal side 25' of the chest belt section 241 and on the distal side 25'' of the lap belt section 242. The radar reflectors 32, 33 are designed as elongated metal-containing fabric strips woven into the belt body, but can also have any other suitable consistency with a large, specific radar signature.

[0022] A buckle stopper 29 is fixed to the belt body 25, which prevents the belt buckle 28 from reaching the radar reflector 33 of the lap belt section 242.

[0023] A radar detector 30 is mounted in the vehicle behind a windshield 13, facing forwards and directed towards the driver's seat 20 or the person operating the vehicle 100. The radar detector 30 consists of a transmitter and a receiver and is operated alternately in CW and FMCW modes several times per second.

[0024] Viewed in the direction of travel, in front of the driver's vehicle seat 20, there is a steering wheel 50 for manually steering the motor vehicle 11. A steering sensor 52 is assigned to the steering wheel 50, which detects the rotational movement and the rotation angle of the steering wheel 50 in the form of a steering signal S with a fine angle and close temporal interval.

[0025] The motor vehicle 11 is equipped with an electronic breathing monitor 40, which is connected via signal links to both the radar detector 30 and the steering sensor 52. These signal links can be implemented, for example, via a CAN bus.

[0026] The breathing monitor 40 has a threshold frequency memory 42 in which one or more breathing threshold frequencies flimit are stored, for example, different breathing threshold frequencies flimit for different driver sizes. During operation, the breathing monitor 40 continuously compares the actual breathing rate f of the driver 100, determined by the radar detector 30, with the assigned breathing threshold frequency flimit. As soon as the actual breathing rate f of the driver 100 falls below the relevant breathing threshold frequency flimit, the breathing monitor 40 outputs a corresponding warning signal W. The breathing rate monitoring function f is suspended by the breathing monitor 40 as soon as and as long as relevant steering movements are detected by the steering sensor 52.

[0027] The breathing monitoring device 40, the safety belt 24 with the radar reflectors 32, 33 and the radar detector 30 together form a vehicle operator monitoring arrangement 10. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 100 576 A1

[0002]

Claims

[1] Vehicle driver monitoring device (10) for monitoring the breathing of a vehicle driver (100) seated and buckled up in a driver's seat (20), with a safety belt (24) assigned to the driver's seat (20), the belt body (25) of which has a radar reflector (32, 33) which, when the safety belt (24) is fastened by the vehicle operator (100), is arranged on a chest belt section (241) and / or a pelvic belt section (242), a radar detector (30) directed at the driver's seat (20), which detects the radar signals reflected by the radar reflector (32, 33) of the seat belt (24) worn by the vehicle driver (100), and an electronic breathing monitor (40) which is connected to the radar detector (30) via a signal link, which determines the breathing rate (f) of the vehicle operator (100) from the signals received by the radar detector (30), and which outputs a warning signal (w) when the breathing rate falls below a limit frequency (flimit) stored in a limit frequency memory (42). [2] Vehicle operator monitoring arrangement (10) according to claim 1, wherein the radar detector (30) is operated in a CW operating mode. [3] Vehicle operator monitoring arrangement (10) according to claim 2, wherein the radar detector (30) alternately switches between the CW operating mode and an FMCW operating mode. [4] Vehicle operator monitoring arrangement (10) according to one of the preceding claims, wherein the radar reflector (33) is associated with the pelvic belt section (242). [5] Vehicle operator monitoring arrangement (10) according to claim 4, wherein the safety belt (24) is designed as a three-point belt with a belt buckle (28) slidably arranged on the belt body (25), wherein the belt body (24) has a buckle stopper (29), and wherein the buckle stopper (29) is arranged between the belt buckle (28) and the radar reflector (33) of the lap belt section (242). [6] Vehicle driver monitoring arrangement (10) according to one of the preceding claims, wherein a steering sensor (52) is associated with a vehicle steering wheel (50) which is connected via a signal connection to the electronic breathing monitoring (40) which incorporates the steering signal (S) coming from the steering sensor (52) into the determination of the breathing rate (f) determined by the breathing monitoring (40).

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