SEAT MONITORING SYSTEM AND METHOD FOR POSITION DETERMINATION

Description

[0001] The invention relates to a seat monitoring system for monitoring the state of at least one seat that can be arranged in the interior of a vehicle and for determining the position of the seat in the interior, as well as a method for determining the position, wherein the seat monitoring system is characterized in particular by the fact that exactly two antennas are used for monitoring and determining the position on the vehicle side and on the seat side.

[0002] A variety of different seat monitoring systems are known from the state of the art.

[0003] In principle, it can be assumed that the seats in a vehicle will increasingly be arranged flexibly in order to provide a wide variety of vehicle interiors adapted to specific tasks.

[0004] For example, for the transport of goods, all seats should be removed from a vehicle, for the transport of passengers all seats or at least some seats should be installed in the vehicle, and existing seats should be able to be arranged differently depending on the situation, e.g. rotated.

[0005] However, this leads to new limitations regarding cable routing in the vehicle, since an interface would have to be provided at every possible point in the vehicle where a seat could be arranged for wired condition monitoring and position detection.

[0006] This also applies in particular to the monitoring of the condition of the seat belts belonging to the seats, whose status (open / closed) must be queried together with seat occupancy in modern vehicles.

[0007] Various wireless seat monitoring systems are proposed in the prior art for this purpose. For example, DE 10 2008 031 494 B4 discloses a seat monitoring system which determines the distance between a transmitter and a receiver from a single signal strength and, by comparing the determined distance with the distances between the transmitter and several predetermined areas in which a seat can be arranged, determines in which of the predetermined areas the seat is located.

[0008] Furthermore, DE 11 2017 005 187 T5 proposes a seat monitoring system which is designed to determine the position of the seat by determining the distances of the seat to exactly three transmitters (antennas).

[0009] In addition to determining the position, the seats, or the seat modules attached to them, are also designed to transmit status values, such as the status of the seatbelt (i.e., whether it is fastened or unfastened), to a control module in the vehicle. However, this requires a sensor module in or on the seats to detect these status values.

[0010] Further seat monitoring systems and aspects of such systems are also known from German patent applications DE 10 2020 107845 A1, DE 10 2021 102155 A1 and US 9 491 581 B1. DE 102020 107845 discloses a seat monitoring system for determining the position of a seat in a vehicle interior, wherein the seat monitoring system comprises a control module and three transmitter modules connected to the control module via signals.

[0011] The invention is based on the objective of providing an alternative system for seat monitoring, which offers a further possibility for determining the position of the seat in the vehicle.

[0012] This problem is solved by the combination of features according to claim 1.

[0013] According to the invention, a seat monitoring system is proposed for monitoring the condition of at least one seat that can be arranged in the interior of a vehicle and for determining the seat's position within that interior. The seat monitoring system can, for example, be located exclusively in the rear of the vehicle or in the entire interior. However, it is usually sufficient to monitor only the rear of the vehicle, since the seats in the front of the interior, especially the driver and front passenger seats, are generally not intended to be removed from the vehicle and are often permanently fixed. The seat monitoring system comprises a control module, exactly two transmitter modules connected to the control module via signals, and at least one seat module.The at least one seat module is assigned to at least one seat, whereby, for example, two or more seats can be connected to form a unit, so that the seat module can be assigned to the unit of seats. The at least one seat module, or each seat module, has a receiver module, and in particular exactly one receiver module. The invention is further characterized in that the exactly two transmitter modules are arranged at a distance from each other and each has exactly one antenna. Furthermore, the receiver module has exactly two antennas, wherein a first antenna of the exactly two antennas of the receiver module is configured to receive a signal from a first transmitter module, or from the exactly one antenna of the first transmitter module, and wherein a second antenna of the exactly two antennas of the receiver module is configured to receive a signal from a second transmitter module, or from the first transmitter module.to receive exactly one antenna of the second transmitting module. In addition, the receiving module is configured to determine the signal strengths (RSSI) of the signals received by the antennas of the receiving module, i.e., a first signal strength of the signal received by the first antenna of the receiving module from the antenna of the first transmitting module, and a second signal strength of the signal received by the second antenna of the receiving module from the antenna of the second transmitting module, for position determination.

[0014] Preferably, the first antenna of the receiving module is designed, for example, by appropriate alignment and / or signal filters, to exclusively receive and / or evaluate the signal from the antenna of the first transmitting module.

[0015] It is also preferably the case that the second antenna of the receiving module is designed, for example by means of a corresponding orientation and / or signal filter, to exclusively receive and / or evaluate the signal of the antenna of the second transmitting module.

[0016] According to an advantageous further development, the receiving module is also provided for in a signal-technical connection to the control module and is configured to send data to the control module. The receiving module can also be configured to send digital information and / or digital data, and furthermore, in particular, information to the control module as to whether the seat module is located in the interior or, if an area within the interior is defined in which the seats can be arranged, whether the seat module is located in that area. Whether the seat module is located in the interior or in that area can be determined, for example, by the fact that the receiving module has received a signal from both transmitting modules. If, for example, a signal is received from only one of the receiving modules, the information that the seat module is not located within the vehicle or the defined area can be sent to the control module.

[0017] The signal connection can be established, for example, via a bidirectional radio link using the antennas of the receiving module and the respective antennas of the transmitting modules. It is also possible that only one radio link, between exactly one antenna of the receiving module and exactly one transmitting module, is bidirectional, while the other radio link is unidirectional.

[0018] Alternatively, additional antennas not used for positioning can be provided. For example, the two antennas of the receiver module can be configured as audio frequency (AF) antennas, and an additional antenna of the seat module, which can also be located outside the receiver module, can be configured as an RF antenna. In this case, the antennas of the transmitter modules are also configured as AF antennas, and an additional antenna connected to the control module serves as an RF antenna. Since neither the additional antenna of the seat module nor the additional antenna connected to the control module is used for positioning, their arrangement within the vehicle is arbitrary and independent of the other antennas.

[0019] The transmitter modules and, if present, an additional antenna are preferably connected to the control module via cable or wired signal connections.

[0020] Basically, the proposed seat monitoring system can be differentiated in that the control module and the transmitter modules can be fixed in a fixed, unchanging position in the vehicle and are thus assigned to the vehicle, and that the seat module is assigned to at least one seat and can be placed in the vehicle with the seat or removed from the vehicle.

[0021] According to an advantageous embodiment of the seat monitoring system, the receiving module is configured to transmit the signal strengths of the signals received by its antennas to the control module for position determination. Alternatively or additionally, the receiving module is configured to transmit the position of the seat within the vehicle interior to the control module. The seat module can then determine the position from the signal strengths received by its antennas. Alternatively or additionally, the receiving module is configured to transmit a signal, particularly a digital one, containing status values ​​to the control module.

[0022] The status values ​​include, in particular, a belt status value (belt closed / open), an occupancy value (seat occupied, seat unoccupied, seat occupied with a child seat), a load value (force acting on the seat surface), a tilt value (tilt of the seat surface and / or backrest), a headrest value (headrest present, not present), and other seat-related values. It should be noted that a seat module can be assigned to multiple seats, and consequently, several similar status values ​​can be recorded and / or transmitted.

[0023] For example, to determine one such state value, several such state values, or similar state values ​​of several seats, it may be provided that the at least one seat module has a sensor module which is configured to determine state values ​​of the at least one seat to which the seat module is assigned.

[0024] Furthermore, it may be provided that the antennas of the exactly two transmitting modules and / or the exactly two antennas of the receiving module are unidirectional, i.e., antennas that transmit data only in one direction. Additionally or alternatively, it may be provided that the antennas of the exactly two transmitting modules and / or the exactly two antennas of the receiving module are one-dimensional transmitting and / or receiving antennas, where "one-dimensional" in this context means that the antennas are designed to transmit or receive signals essentially only in one direction in space.

[0025] According to another possible variant of the seat monitoring system, at least one seat can be arranged within a predetermined, and in particular rectangular, area in the vehicle's interior. The respective positions of exactly two transmitter modules relative to this area are known and remain constant. By determining the distances between the seat module and the transmitter modules, two points of intersection of circles centered around the transmitter modules are obtained in a plane, with the respective distance between them as the radius. If an intersection point lies outside the predetermined area, this point can immediately be ruled out as the seat's position, or it can be concluded that the intersection point lying within the area corresponds to the position of the seat or the seat module.

[0026] This results in a further advantageous variant of the seat monitoring system in that the respective predetermined position of the transmitter modules relative to the area is chosen such that of two intersection points of all possible circles, each of which has one of the transmitter modules as its center, one intersection point lies within the area and one intersection point lies outside the area.

[0027] In a particularly advantageous embodiment, the first transmitting module can be arranged along a first axis and the second transmitting module along a second axis inclined to the first axis. Preferably, the first and second axes are orthogonal to each other. The axes can, for example, define the area or be located outside the area.

[0028] It is usually necessary to be able to mechanically fix the seats in the vehicle so that they are detachably but, for the duration of the fixation, at least via the designated interface, are fixed in position within the vehicle. An advantageous embodiment provides that at least one seat has a seat base for detachably fixing the seat in the vehicle, serving as an interface to the vehicle. Furthermore, the seat module has a predetermined and fixed position relative to the seat base, such that the seat module of a seat located in this area is positioned in a predetermined plane. If the module that performs the position determination, i.e., the seat module and / or the control module, is aware of this relative position of the seat module to the seat base, then the seat module can be adjusted accordingly.If the plane and the positions of the transmitter modules are known, the position of the seat module relative to the transmitter modules can be determined more accurately, since any possible difference between the position of the transmitter modules and the position of the seat module along the vertical axis of the vehicle can be taken into account.

[0029] Furthermore, according to an advantageous variant, it is provided that the at least one seat can be arranged or detachably fixed in the area on a predetermined grid having a mechanical detent point and / or on at least one rail aligned with the predetermined grid.

[0030] This grid and / or, if applicable, the course of at least one rail on the grid can also be taken into account when determining the position, in order to determine the position with higher accuracy and at the same time to obtain additional information.

[0031] Preferably, the at least one seat module and / or the control module is designed to determine the respective distance of the at least one seat module to the transmitting modules from the signal strengths of the signals received by the antennas of the receiving module, and to determine the position of the seat module in the vehicle from the distances.

[0032] If the grid or the positions of the detents and / or the course and positioning of the rails are known, it can further be provided that the at least one seat module and / or the control module is designed to determine, from the signal strengths of the signals received by the antennas of the receiving module, a respective distance of the at least one seat module to the transmitting modules and, from the distances and from the predetermined grid, the position of the seat module and, in particular, an orientation of the seat assigned to the seat module in the vehicle, whereby additional information can also be determined from a deviation of a position of the seat module from the grid.

[0033] For better understanding, the following examples are given: If the position determined on the basis of the signal strengths deviates slightly from a detent point or a rail profile, it can be assumed that the corresponding seat is located at the detent point or on the rail.

[0034] Assuming that the position determined based on the signal strength is sufficiently accurate, a rotation and / or orientation of the seat around the detent point can be determined from a deviation to a (nearest and therefore corresponding) detent point.

[0035] If a seat module is assigned to exactly one seat and positioned on that seat such that it always rests on a detent point, then a position determined from the signal strengths that corresponds to a detent point can be used to assume that the seat module is assigned to exactly one seat. Conversely, if, for example, another seat module is assigned to exactly two seats and positioned on both seats such that it is always offset from a detent point by a known amount, then a position determined from the signal strengths and the resulting offset to the nearest detent point can be used to assume that the seat module is assigned to two seats, and whether the seats are oriented towards the front or rear of the vehicle. No additional sensors are required for this, as these values, understood as state values, can be determined directly from a deviation of the determined position from the grid.

[0036] It may be designed so that only some of the seats are arranged in or removable from the vehicle's interior. In particular, the driver's seat may be permanently mounted in the interior. However, the driver's seat may also be positioned within the interior and include a seat module, allowing its position to be calibrated using the previously known and fixed position of the driver's seat and its associated seat module.

[0037] Another aspect of the invention relates to a method for determining the position of a seat in the interior of a vehicle using a seat monitoring system according to the invention. The method calculates a first distance of the seat module from the first transmitting module and a second distance of the seat module from the second transmitting module based on the signal strengths (RSSI) of the signals received by the two antennas of the receiving module. Subsequently, possible positions of the seat module, particularly those lying in a predetermined plane, are determined from the first and second distances. If more than one position is possible, impossible positions can be excluded, or a single correct position can be determined by considering additional information. The correct position, or the only correct position, is understood to be a position within the vehicle.Determining the actual position is possible by considering a predetermined area within which the seats can be arranged. Additionally or alternatively, a grid on which the seats can be arranged can be considered. Furthermore, a predetermined transmission direction for the antennas of the transmitting modules and / or a predetermined reception direction for the antennas of the receiving module can be considered, either additionally or alternatively.

[0038] The features disclosed above can be combined in any way, provided that this is technically possible and they do not contradict each other.

[0039] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a seat monitoring system in a first seating arrangement; Fig. 2 a seat monitoring system in simplified representation.

[0040] The figures are schematic examples. Identical reference symbols in the figures indicate identical functional and / or structural features.

[0041] In the Figures 1 and 2 Each of the following is shown: a seat monitoring system 1 for monitoring the state of at least one seat 2 that can be arranged in an interior space, and more precisely in an area 30 in the interior space of a vehicle, and for determining the position of the seat 2 in the interior space or in the area 30. This corresponds to Figure 1 a supervision of a possible seat monitoring system 1 and Figure 2 a further schematic representation of a seat monitoring system 1, which is also the seat monitoring system 1 according to Figure 1 can act.

[0042] The seat monitoring system 1 comprises a control module 10 integrated into the vehicle and exactly two transmitter modules 11, 12 which are connected to the control module 10, for example via a physical line 17. The transmitter modules 11, 12 are fixed at a predetermined position relative to the area 30 and are arranged along axes X, Y that define the rectangular area 30 and are orthogonal to each other.

[0043] Furthermore, the seat monitoring system 1 has at least one seat module 20, the number of seat modules 20 corresponding to the number of seats 2 arranged in the vehicle or the number of seat units 200, which can be formed from several seats 2. Accordingly, each seat module 20 is assigned to at least one seat 2. As in Figure 1 A seat module 20 is shown, assigned to a seat unit or seat group 200 consisting of two interconnected seats 2.

[0044] Furthermore, each seating module 20 has a reception module 21, as described in Figure 2 The two transmitter modules 11 and 12 are spaced apart from each other and each has exactly one in Figure 2 Antenna 13, 14 shown.

[0045] Each receiving module 21 of each seating module 20 also has exactly two antennas 23, 24, wherein a first antenna 23 of the receiving module 21 is configured to receive a signal from a first transmitting module 11 of the exactly two transmitting modules 11, 12, and a second antenna 24 of the receiving module 21 is configured to receive a signal from a second transmitting module 12 of the exactly two transmitting modules 11, 12.

[0046] The receiving module 21 is designed to determine the signal strengths of the signals received by the antennas 23, 24 of the receiving module 21 for position determination.

[0047] The distances A1, A2 of the receiver module 21 from the two transmitter modules 11, 12 can be determined from the signal strengths (RSSI). Since the receiver module 21 and the seat module 20 cannot be located arbitrarily in space, but are always arranged in a specific plane, which, for example, runs parallel to the vehicle floor, two possible positions of the seat module 20 relative to the transmitter modules 11, 12 can be deduced from the distances.

[0048] A first distance A1 corresponds to the distance of the receiving module 21 from the first transmitting module 11 in the plane and a second distance A2 corresponds to the distance of the receiving module 21 from the second transmitting module 12 in the plane.

[0049] Assuming a first circle K1 with a radius corresponding to the distance A1 and its center in the first transmitter module 11, and a second circle K2 with a radius corresponding to the distance A2 and its center in the second transmitter module 12, then, in the special case where the distances A1 and A2 are identical, exactly one intersection point results, which then corresponds to the position of the seat module 20. If the distances A1 and A2 are not identical, exactly two intersection points S1 and S2 of the circles K1 and K2 always result in the plane, where both intersection points S1 and S2 can be the position of the seat module 20 relative to the transmitter modules 11 and 12.

[0050] However, due to the chosen arrangement of the transmitter modules 11, 12 to the area 30, one of the two intersection points S1, S2 lies within the area 30 and the other intersection point lies outside the area 30, so that it can be immediately concluded that the intersection point lying within the area 30 corresponds to the position of the seat module 20.

[0051] From this position of the seating module 20, a position relative to an arbitrarily selectable coordinate system can be determined by appropriate conversion.

[0052] Furthermore, such a conversion can be supplemented by a grid 34, on which the seats 2 can be arranged, in order to increase the accuracy of the position or to obtain additional information about seat 2.

[0053] It can be assumed that the seats 2 or the seat units are mechanically fixed in the vehicle and that a grid is provided in the vehicle for this purpose, which may, for example, have locking points or locking rails.

[0054] If the position of the seat module 20 on a seat 2 relative to a detent point or the grid 34 to which the seat 2 is attached is known, this deviation can be determined and further information can be generated from this.

[0055] As in Figure 1As shown, in the seating unit 200, the seat module 20 is arranged vertically in the center of the seating unit 200, as illustrated. The position of the seat module 20 of the seating unit 200 lies precisely between two horizontally extending locking planes 341 of the grid 34, and not, as with individual seats 2, exactly on a horizontally extending locking plane 341 of the grid 34. Therefore, the position directly identifies that it is not a seat module 20 of an individual seat 2, but rather a seat module 20 of a seating unit 200.

[0056] The determination of the distances A1, A2 and the determination of the position of the seat module 20 can be carried out by the seat module 20 itself and, for example, by a corresponding processing unit 26 of the seat module 20. The position thus determined can then be sent to the control module 10 via a feedback channel. The feedback channel can be configured as described in Figure 2represented by a separate radio link 15 for unidirectional or bidirectional data transmission, for which the seat module 20 may, for example, have an RF antenna 25.

[0057] Alternatively, the distances A1, A2 or only the signal strengths can be sent from the seat module 20 to the control module 10 and the position of the seat module 20 can be determined by the control module.

[0058] Furthermore, the control module 10 can have an interface 16 for data transmission to other control units of the vehicle or be connected to them via CAN bus.

Claims

1. A seat monitoring system (1) for monitoring a state of at least one seat (2) that can be arranged in an interior of a vehicle and determining the position of the seat (2) in the interior, wherein the seat monitoring system (1) comprises a control module (10), exactly two transmission modules (11, 12) which are signal-connected to the control module (10), and at least one seat module (20) which is associated with at least one seat (2) and which has a reception module (21), wherein the exactly two transmission modules (11, 12) are arranged at a distance from one another and each have exactly one antenna (13, 14), the reception module (21) has exactly two antennas (23, 24), a first antenna (23) of the reception module (21) being designed to receive a signal from a first transmission module (11) of the exactly two transmission modules (11, 12), and a second antenna (24) of the reception module (21) being designed to receive a signal from a second transmission module (12) of the exactly two transmission modules (11, 12), wherein the reception module (21) is designed to determine signal strengths of the signals received by the antennas (23, 24) of the reception module (21) for position determination.

2. The seat monitoring system according to claim 1, wherein the reception module (21) is signal-connected to the control module (10) and is designed to transmit data to the control module (10), the reception module (21) being designed in particular to transmit digital information and, particularly in addition, information about whether the seat module (20) is arranged in the interior to the control module (10).

3. The seat monitoring system according to claim 2, wherein the reception module (21) is designed to transmit the signal strengths of the signals received by the antennas (23, 24) of the reception module (21) to the control module (10) for position determination and / or to transmit a position of the seat (2) in the interior to the control module (10), which position can be determined by the seat module (20) from the signal strengths of the signals received by the antennas (23, 24) of the reception module (20), and / or to transmit a particularly digital signal containing state values to the control module (10).

4. The seat monitoring system according to any one of the preceding claims, wherein the at least one seat module (20) has a sensor module (22) which is designed to determine state values of the at least one seat (2) with which the seat module (20) is associated.

5. The seat monitoring system according to any one of the preceding claims, wherein the antennas (13, 14) of the exactly two transmission modules (11, 12) and / or the exactly two antennas (23, 24) of the reception module (21) are unidirectional antennas and / or one-dimensionally transmitting and / or receiving antennas.

6. The seat monitoring system according to any one of the preceding claims, wherein the at least one seat (2) can be arranged in a predetermined and, in particular, rectangular area (30) in the interior of the vehicle, and the respective position of the exactly two transmission modules (11, 12) relative to the area (30) is known and unchangeable.

7. The seat monitoring system according to the preceding claim, wherein the respective predetermined position of the transmission modules (11, 12) is selected such that, of two intersection points (S1, S2) of all possible circles (K1, K2) whose center is one of the respective transmission modules (11, 12), a first intersection point (S1) lies within the area (30) and a second intersection point (S2) lies outside the area (30).

8. The seat monitoring system according to the preceding claim, wherein the first transmission module (11) is arranged along a first axis (X) and the second transmission module (12) is arranged along a second axis (Y) oblique to the first axis (X), the first axis (X) and the second axis (Y) being in particular orthogonal to one another.

9. The seat monitoring system according to any one of preceding claims 6 to 8, wherein the at least one seat (2) has a seat base for releasably fixing the seat (2) in the vehicle, the seat module (20) having a predetermined and fixed position relative to the seat base, so that the seat module (20) of a seat that is arranged in the region (30) is arranged in a predetermined plane.

10. The seat monitoring system according to any one of claims 6 to 9, wherein the at least one seat (2) can be arranged on a predetermined grid (34) having mechanical locking points and / or on at least one rail that is aligned with the predetermined grid (34) in the area (30).

11. The seat monitoring system according to any one of the preceding claims, wherein the at least one seat module (20) and / or the control module (10) are / is designed to determine a respective distance (A1, A2) of the at least one seat module (20) to the transmission modules (11, 12) from the signal strengths of the signals received by the antennas (23, 24) of the reception module (21) and to determine the position of the seat module (20) in the vehicle from the distances (A1, A2).

12. The seat monitoring system according to the two preceding claims, wherein the at least one seat module (20) and / or the control module (10) is designed to determine a respective distance (A1, A2) of the at least one seat module (20) to the transmission modules (11, 12) from the signal strengths of the signals received by the antennas (23, 24) of the reception module (21) and to determine the position of the seat module (20) and in particular an orientation of the seat (2) associated with the seat module (20) in the vehicle from the distances (A1, A2) and from the predetermined grid (34).

13. A method for determining a position of a seat (2) in an interior of a vehicle with a seat monitoring system (1) according to any one of the preceding claims, wherein a first distance (A1) of the seat module (20) from the first transmission module (11) and a second distance (A2) of the seat module (20) from the second transmission module (12) is calculated from the signal strengths of the signals received by exactly two antennas (23, 24) of the reception module (21), wherein possible positions of the seat module (20) lying particularly in a predetermined plane are determined from the first distance (A1) and the second distance (A2), and wherein an actual position of the seat module (20) is determined from the possible positions through a predetermined area (30) in which the seats (2) can be arranged and / or through a grid (34) on which the seats (2) can be arranged and / or through a predetermined transmission direction of the antennas (13, 14) of the transmission modules and / or through a predetermined reception direction of the antennas (23, 24) of the reception module (21).