Vehicle seat having integrated weight detection

Abstract

The invention relates to a vehicle seat (1) comprising: a seat-part assembly (10); a backrest-part assembly (11); a base assembly (13) supporting at least the seat-part assembly (10); and an adjustment device (12) for adjusting the seat-part assembly (10) and / or the backrest-part assembly (11) relative to the base assembly (13) by means of a drive apparatus (3). A control system (14) is provided which is coupled to the drive apparatus (3) and which is designed to perform the following steps: activating the drive apparatus (3) to bring about an adjustment of the seat-part assembly (10) and / or of the backrest-part assembly (11) relative to the base assembly (13); detecting at least one value of a parameter of the adjustment device (12) and / or of the drive apparatus (3) during the adjustment; and determining a weight acting on the vehicle seat (1), in particular on the seat-part assembly (10), based on the at least one detected value of the parameter during the adjustment, wherein the control system (14) is designed to detect a signal which indicates that the at least one detected value of the parameter is faulty and, in response to the signal, to repeat the detection of the at least one value of the parameter of the adjustment device (12) and / or of the drive apparatus (3), and / or to discard the at least one previously detected value of the parameter.

Description

[0001] Vehicle seat with integrated weight detection

[0002] Description

[0003] The proposed solution relates to a vehicle seat, a system comprising the vehicle seat, a method, a corresponding computer program product and a non-transitory computer-readable storage medium.

[0004] Some functions in today's vehicles are based on seat occupancy detection. If a vehicle seat is occupied, controls in the vehicle regularly check whether the corresponding seatbelt is also fastened. Furthermore, the deployment of airbags can be linked to seat occupancy. In some cases, these or other functions can be improved if it is not only detected whether the vehicle seat is occupied in any way, but also if the weight acting on the vehicle seat is quantified. For example, an alarm for an unfastened seatbelt can be dispensed with if the vehicle seat is occupied by an object (e.g., a bag) but not by a passenger. The deployment of airbags can also be adapted to the weight of the passenger in order to achieve an optimized restraint effect. In practice, for example,So-called biadder mats or piezo elements are embedded in a seat part to detect seat occupancy and perform an approximate weight measurement. However, such components require installation space and are complex to manufacture, partly due to the additional wiring.

[0005] DE 10 2006 061 669 A1 describes a method for determining an indication of the occupant weight of a vehicle seat, wherein a seat element of the vehicle seat is adjustable by means of a drive unit, comprising the following steps: providing at least one measurement signal representing a state of the drive unit; controlling the drive unit for at least a predetermined period of time; during the control period, detecting the measurement signal, determining a load torque from the measurement signal according to a motor model; and determining an indication of the occupant weight of the seat element depending on the load torque. An electric drive unit can be provided for adjusting the seat height. However, it has been shown that the accuracy of the measurement is in need of improvement.

[0006] DE 10 2017 217 331 A1 describes a method for operating an electromotive massage device of a seat, in particular of a motor vehicle, which comprises a massage drive with an electric motor, in which the electric motor is energized, a torque of the electric motor is detected and a reference value is determined therefrom, and an occupancy of at least one section of the seat is determined on the basis of the reference value.

[0007] DE 103 35 734 A1 relates to a method for seat occupancy detection in a motor vehicle with at least one actuator for seat adjustment. The electrical power supply to the actuator(s) for seat adjustment is recorded during their activation and evaluated as a measure of seat occupancy. However, the accuracy of this measurement also has potential for improvement.

[0008] The task is to improve weight detection in vehicle seats.

[0009] This object is achieved by an article having the features of claim 1.

[0010] According to this, a vehicle seat comprises a seat subassembly, a backrest subassembly, a base assembly supporting (at least) the seat subassembly, and an adjustment device, e.g., a height adjustment device, for adjusting the seat subassembly and / or the backrest subassembly relative to the base assembly (specifically, e.g., a distance between the seat subassembly and the base assembly) using a drive device. It is provided that the vehicle seat further comprises a control system which is coupled to the drive device and which is configured to carry out the following steps: Activating the drive device to effect an adjustment of the seat subassembly and / or the backrest subassembly relative to the base assembly (specifically, for adjusting, e.g., increasing or decreasing, the distance between the seat subassembly and the base assembly in a first direction, e.g.,up or down); detecting one or at least one value of a parameter of the adjustment device (e.g. height adjustment device) and / or the drive device during the adjustment (e.g. in the first direction); and determining a weight acting on the vehicle seat, in particular on the seat part assembly, based on the at least one value (or values) of the parameter detected during the adjustment. Furthermore, it is provided that the control system is configured to detect a signal indicating that the detected at least one value of the parameter is incorrect, and in response to the signal, to repeat the detection of the at least one value of the parameter of the adjustment device and / or the drive device and / or to discard the previously detected at least one value of the parameter.

[0011] This is based on the realization that a weight measurement can be inaccurate due to various factors, such as movement of the seat occupant during the measurement, driving over a bumpy road during the measurement because the seat occupant left their seat and placed a bag on it instead, or similar factors. By creating the ability to process one or more additional signals that could indicate an inaccurate measurement, it is possible to discard the measurement results and / or remeasure them, resulting in more accurate and reliable measurements and thus overall improved weight recording.

[0012] The parameter can be an electrical parameter, in particular a current, a voltage or a power. Alternatively or additionally, it can be provided that the parameter specifies a torque. Alternatively or additionally, it can be provided that the parameter specifies a speed (e.g. of the drive device), in particular the maximum speed reached during adjustment. These parameters allow simple conversion into a weight, e.g. by means of a conversion rule and / or a table (lookup table, LUT). The parameter can in particular refer to one or more drive motor(s) of the drive device. Optionally, the control system is set up (for each of the two directions) to calculate a voltage and / or a current of the drive device starting from a starting value (e.g.Zero) until a component of the height adjustment device, in particular a drive motor of the drive mechanism, is set in motion from a standstill. The value of the parameter is then, for example, the reached current or voltage value. The control system can also be configured to stop the drive mechanism as soon as it has registered the movement. In this way, the weight measurement can be achieved with only minimal movement. The adjustment in the first and second directions is thus minimal and hardly noticeable or unnoticeable for a seat occupant.

[0013] Furthermore, it can be provided that the parameter specifies an adjustment path covered within a specific (in particular predetermined) time, in particular the length of this adjustment path, or an adjustment time required for a specific (in particular predetermined) adjustment path. These parameters also allow for simple conversion into a weight, e.g., using a conversion rule and / or a LUT.

[0014] The adjustment device can be a height adjustment device for adjusting a distance between the seat subassembly and the floor assembly. The control system can be configured to activate the drive device for adjusting the distance between the seat subassembly and the floor assembly in one direction. This allows for particularly accurate weight measurements.

[0015] The direction can be a first direction and the control system can further be configured to perform the following steps (e.g. after the steps of activating and detecting with respect to the first direction): activating the drive device to adjust the distance between the seat part assembly and the floor assembly in a second direction opposite to the first direction; and detecting a value of the parameter of the height adjustment device and / or the drive device during the adjustment in the second direction. In this case, the control system can be configured to determine a weight acting on the seat part assembly based on the detected values ​​of the parameter from the adjustments in both directions. This is based on the idea that a height adjustment motor causes a torque through the adjustment which corresponds to a current.This current can be measured via the control system (which may include electronics located on the vehicle seat and / or a central vehicle control system) and used to evaluate the weight increase. Furthermore, the described solution is based on the realization that friction and tolerances can affect the accuracy of weight measurement, but that measuring in both adjustment directions allows such influences to be offset. This allows for particularly precise weight determination with a very simple setup.

[0016] The signal indicates, for example, whether the vehicle seat and / or a passenger sitting therein moves due to a further force during the detection of the at least one value of the parameter of the adjustment device, in particular the height adjustment device, and / or the drive device. The control system can be configured to detect this signal. The control system can be configured to generate the signal itself or to receive it from a communicatively connected component.

[0017] The additional force may be independent of the adjustment mechanism and the drive device, e.g., a force acting externally on the vehicle seat. This can, for example, detect a movement by the seat occupant that distorts the weight measurement.

[0018] The control system can be configured to detect the signal by analyzing a current profile. This allows for accurate detection of the measurement quality without the need for additional sensors or the like.

[0019] For example, the signal indicates that a target state deviates from an actual state, which suggests that at least one of the recorded values ​​of the parameter is faulty. The target state is specified, for example, by a reference value.

[0020] In one embodiment, the signal indicates a fluctuation in a current strength of the drive device. Alternatively or additionally, the signal can indicate a deviation from an average value of a current strength of the drive device. Alternatively or additionally, the signal can indicate a gradient of an average value of a current strength of the drive device (e.g., calculated over a running time window). This makes it easy to carry out quality control and verification of the weight measurement. The value(s) or, for example, the temporal progression of the current values ​​used for the signal can be the same as those used for the weight measurement, or else different.

[0021] The current intensity is, for example, a phase current of a multi-phase drive motor of the drive device. The drive motor is, for example, a BLDC motor. This enables accurate adjustment and precise measurement. The control system can be configured to apply a Fourier transformation, in particular a fast Fourier transformation (FFT), to measured values, in particular to current measured values ​​and / or position measured values. In this case, it can be provided that the signal corresponds to the exceeding of a threshold value in a predetermined frequency range. In this way, frequencies can be determined with particular precision that are not present or only present to a small extent in a correct measurement. An FFT normally creates the frequency spectrum of a time-based signal in the frequency domain. The FFT of the current intensity could be speed-dependent; for example, at 6000 RPM, an expected spectral component would be at the rotational frequency (100 Hz) and another, for exampleat an nth harmonic. If the speed changes, the positions of the spectral components change. Another possibility is to record position-controlled measurements instead of time-controlled sampling and measurement values, i.e. a specified number of measurement values ​​per engine revolution, e.g. 10x per engine revolution. This means that the FFT result on the x-axis no longer corresponds to an absolute frequency, but to a value relative to the rotational frequency. This would then be the same or at least similar for all speeds, which can simplify the evaluation. In the case of typical disturbances, e.g. jiggling or a rough road stretch at a certain frequency, the time-based method with absolute frequencies is also useful. It is also conceivable to perform both a time-based and a position-based FFT analysis and to examine both results for certain spectral components in order to detect an erroneous measurement.

[0022] The control system can be configured to detect the signal by comparing an empty weight measurement without occupants with the weight from a previous empty measurement. This allows it to be determined whether the overall measurement is impaired.

[0023] Furthermore, the control system can be configured to detect the signal by querying a sensor and / or the activation and / or position of an adjustable component. If, for example, the backrest is folded forward, it can be detected that the seat is unoccupied and a weight measurement can be discarded. The sensor can also detect whether the seat is occupied. The activation of, for example, an entertainment system on or in front of the vehicle seat can imply that the vehicle seat is occupied. A closed or unlocked seat belt buckle can also provide an indication of whether the vehicle seat is occupied. Several such inputs can be combined with one another to calculate a probability value that indicates the probability that the vehicle seat is occupied. If the probability is below a minimum level, the measured weight value can be discarded.

[0024] The control system can also be configured to detect the signal by comparing a current intensity versus position (or versus time) with a stored reference curve. This allows for particularly precise plausibility checks.

[0025] The control system can be configured to activate the drive device in the first direction and in the second direction for a predetermined time and / or over a predetermined adjustment range (e.g., measured by the number of motor revolutions). Thus, for example, the power can be determined over the predetermined adjustment range or the predetermined adjustment time and used to determine the weight.

[0026] The drive device can be activated at different adjustment speeds. In other words, the drive device can enable a variable adjustment speed. The control system is configured, for example, to signal an adjustment speed to the drive device. Furthermore, the drive device can have a maximum adjustment speed. For example, the drive device is operated at the maximum adjustment speed when the seat height is adjusted. The control system can be configured to activate the drive device at an adjustment speed in the first direction and then at this (or a different) adjustment speed in the second direction, which is (in each case) lower than the maximum adjustment speed. As a result, the weight measurement process is not disruptive to a seat occupant.In particular, the adjustment speed can be (in each case) less than or equal to 50% of the maximum adjustment speed, optionally less than or equal to 10% of the maximum adjustment speed, or even less than or equal to 1% of the maximum adjustment speed, so that the adjustment is barely perceptible. If the drive device has a minimum adjustment speed at which it can be operated, the control system can be configured to activate the drive device at this minimum adjustment speed in the first direction and then at the minimum adjustment speed (or a minimum adjustment speed) in the second direction. The measurement can then be considered quasi-static.

[0027] The control system can have a storage medium in which, for example, a model is stored that assigns a corresponding value of an acting weight to parameter values, in particular to each possible value of the parameter. Using this model (e.g., in the form of a LUT), the weight can be determined in a particularly simple manner. The model can also be a machine learning model that has been trained, for example, with various weight loads.

[0028] Optionally, the model assigns a value of an acting weight to the parameter values ​​(in particular, to each possible value of the parameter) for several possible adjustment positions of the height adjustment device. This allows for the fact that, due to the kinematics of the height adjustment device, not every adjustment position requires the same torque.

[0029] Optionally, the model assigns (independently of each other) a value of an acting weight to the values ​​of the parameter (in particular, to each possible value of the parameter) with respect to a displacement in the first direction, on the one hand, and to a displacement in the second direction, on the other hand. This can further improve the accuracy of the measurement.

[0030] The control system is configured, for example, to determine the acting weight separately based on the detected value of the parameter for the first direction and based on the detected value of the parameter for the second direction. Optionally, the control system is further configured to determine the weight acting on the seat subassembly 10 from the two weight values ​​thus obtained, specifically to calculate an average value. In particular, a weighted average can be calculated, for which each of the two individual values ​​is multiplied by a weighting factor.

[0031] The parameter can be recorded for a drive motor of the drive device. Optionally, the drive device comprises a plurality of drive motors. The control system can be configured to record a value of the parameter for each of the plurality of drive motors during adjustment and to determine the weight acting on the seat part assembly based on the recorded values ​​of the parameter of the plurality of drive motors. For this purpose, the values ​​of the parameter for the drive motors can be added together and the weight can then be determined based on the added value. Alternatively, a corresponding weight acting on the seat part assembly can be determined separately for each individual drive motor and then, for example, an average value can be calculated from this. As described above, the adjustment in the first direction is carried out first and then the adjustment in the second direction.Measured values ​​from multiple drive motors can further increase the accuracy of the determined weight. The control system can be configured to record the values ​​of the parameter for calibration purposes when no weight is acting on the vehicle seat. This can be done in the manner described above, i.e. by activating the drive device to adjust the distance between the seat subassembly and the floor assembly in the first direction and recording the value of the parameter of the drive device during the adjustment in the first direction; as well as activating the drive device to adjust the distance between the seat subassembly and the floor assembly in the second direction and recording the value of the parameter of the drive device during the adjustment in the second direction. Since the weight acting on the seat subassembly is known (0 kg), the recorded values ​​can be saved as a reference and / or used for calibration, e.g.of the model. Calibration can correct for aging-related effects, such as changes in efficiency, friction, etc., over the lifetime of the vehicle seat.

[0032] Optionally, the control system can be configured to automatically repeat calibration at specified intervals. This ensures consistently high weight accuracy.

[0033] The drive device, in particular each of a plurality of drive devices, can comprise a brushless DC motor. Such motors allow for particularly good adjustment of the adjustment speed by adjusting the rotational speed. Generally, the adjustment speed can be determined by the rotational speed.

[0034] The control system is optionally configured to receive data relating to seat occupancy of the vehicle seat from a camera or other detection device (such as radar). The data may be camera images or other data which the control system evaluates, e.g. to determine the size of a passenger sitting on the vehicle seat and / or their position on the vehicle seat. This data can be used with the determined weight. Furthermore, the determined weight can be corrected based on the seat occupancy data; e.g. the position of the passenger on the vehicle seat can be used to correct a (too low) measured weight.

[0035] The control system can include a memory in which a retrievable model is stored, which establishes at least one relationship between the weight acting on the seat subassembly and the input values ​​of the adjuster position and the value of the measured parameter. This enables fast and reliable evaluation.

[0036] It may be advantageous if the control system is configured such that the detection of at least one value of the parameter in the first direction and / or in the second direction occurs within a period of one complete revolution of a gear stage of the height adjustment device and / or the drive mechanism. This allows for compensation of irregularities due to gear modulation, allowing a more precise result to be achieved.

[0037] According to an advantageous development, the control system can be configured to take vehicle inclination into account when determining the weight acting on the seat subassembly. Since the inclination of the vehicle in which the vehicle seat is installed can influence the weight determination, an excessively large vehicle inclination can lead to incorrect weight determination. To prevent this, the vehicle inclination can be considered as an additional input value.

[0038] According to an advantageous development, the control system can be configured to consider a temperature when determining a weight acting on the seat subassembly. The temperature can influence certain material properties, particularly of a component of the height adjustment device and / or the drive mechanism, so that large temperature fluctuations can also impair the determination of the weight. To avoid this, the temperature can be considered as an additional input value. For example, this can be the temperature in a vehicle interior.

[0039] The features described above can equally also be used to further develop the method and / or system described and / or claimed herein.

[0040] According to one aspect, a system is provided comprising the vehicle seat according to any embodiment described herein and the camera and / or the other detection device.

[0041] According to a further development of the system, it can be provided that it comprises a measuring device for measuring the setting of another seat adjustment device, in particular for adjusting a backrest angle and / or a seat inclination. According to one aspect, a computer-implemented method is provided for determining a weight acting on a vehicle seat, in particular on the vehicle seat according to any embodiment described herein. The method comprises the following steps: activating a drive device of a (height) adjustment device of the vehicle seat for adjusting (e.g., a distance) a seat subassembly and / or a backrest subassembly relative to a floor assembly of the vehicle seat (e.g., in a first direction); and detecting (at least) one value of a parameter of the (height) adjustment device and / or the drive device during the adjustment (e.g., in the first direction).Optionally, the method comprises activating the drive device to adjust the distance between the seat part assembly and the floor assembly in a second direction opposite to the first direction; and detecting a value of the parameter of the (height) adjustment device and / or the drive device during the adjustment in the second direction. The method further comprises determining a weight acting on the seat part assembly based on the one or more detected values ​​of the parameter. In this case, a control system detects a signal which indicates that the detected at least one value of the parameter is incorrect, and in response to the signal, the detection of the at least one value of the parameter of the adjustment device and / or the drive device is repeated and / or the previously detected at least one value of the parameter is discarded.Regarding the advantages, reference is made to the information on the vehicle seat above.

[0042] The method may comprise steps according to the various embodiments of the control system described above.

[0043] According to one aspect, a computer program product is provided, comprising instructions which, when executed by one or more computers (e.g. in the form of the control system described above), cause them to carry out the method described above.

[0044] According to one aspect, a non-volatile computer-readable storage medium is provided on which instructions are stored which, when executed by one or more computers (e.g. in the form of the control system described above), cause them to carry out the method described above.

[0045] According to one aspect, a vehicle seat is specified, in particular according to any of the embodiments described herein, comprising: a seat part assembly, a base assembly supporting the seat part assembly, a height adjustment device for adjusting a distance between the seat part assembly and the base assembly with a drive device, and a control system coupled to the drive device, which is configured toto carry out the following steps: activating the drive device to adjust the distance between the seat part assembly and the floor assembly in a first direction; detecting a value of a parameter of the height adjustment device and / or the drive device during the adjustment in the first direction; activating the drive device to adjust the distance between the seat part assembly and the floor assembly in a second direction opposite to the first direction; detecting a value of the parameter of the height adjustment device and / or the drive device during the adjustment in the second direction; and determining a weight acting on the seat part assembly based on the detected values ​​of the parameter. In one embodiment, it is further provided that the control system is configured to detect,whether the vehicle seat and / or an occupant sitting thereon moves in the first direction and / or in the second direction due to a further force, in particular a force independent of the height adjustment device and / or the drive device, during the detection of the at least one value of the parameter of the height adjustment device and / or the drive device, preferably in such a way that an analysis of the current profile can be or is taken into account, in particular wherein, upon detection of a movement due to a further force, the detection of the at least one value of the parameter of the height adjustment device and / or the drive device is repeated and / or the previously detected value of the parameter is discarded.

[0046] The concept underlying the invention will be explained in more detail below with reference to the exemplary embodiments illustrated in the figures. They show:

[0047] Fig. 1 is a schematic view of a vehicle seat with a

[0048] Height adjustment device which is carried by a floor assembly, wherein the floor assembly is designed, for example, in the form of a longitudinal adjustment device;

[0049] Fig. 2 is a view of a seat subassembly of a vehicle seat;

[0050] Fig. 3 is a plan view of the arrangement according to Fig. 2;

[0051] Fig. 4 is a partially enlarged view of the arrangement according to Fig. 2, showing a drive device on a pivoting element for connecting the seat part assembly to a floor assembly in the form of a longitudinal adjustment device;

[0052] Fig. 5 shows an alternatively designed drive device for the vehicle seat according to Fig. 1;

[0053] Fig. 6 shows a method for determining a weight acting on the vehicle seat according to Fig. 1; and

[0054] Fig. 7 shows a current intensity of a drive motor versus a position of a component adjusted by it.

[0055] Fig. 1 shows a vehicle seat 1, which can be arranged, for example, as a front seat or as a rear seat in the second or third row of seats in a vehicle. The vehicle seat 1 has a seat subassembly 10, on which a backrest subassembly 11 is arranged in an inclination-adjustable manner and which is connected via a height adjustment device 12 to a base assembly 13 in the form of a longitudinal adjustment device for longitudinally adjusting the vehicle seat 1 along a longitudinal direction X.

[0056] The longitudinal adjustment device 13 typically has, as can be seen from Fig. 1 in conjunction with Figs. 2 and 3, two pairs of guide rails 130A, 131A, 130B, 131B, each arranged on one side of the seat subassembly 10 and spaced apart from one another along a transverse direction Y perpendicular to the longitudinal direction X. Lower guide rails 131A, 131B are fixedly connected to a vehicle floor 2. Upper guide rails 130A, 130B, in contrast, are coupled to pivot elements 120A, 121A, 120B, 121B of the height adjustment device 12, via which the floor assembly 13 is connected to the seat subassembly 10.

[0057] The pivot elements 120A, 121A, 120B, 121B together with the upper guide rails 130A, 130B and side frame parts 100A, 100B of the seat part assembly 10 form two pairs of four-bar linkages. For this purpose, the pivoting elements 120A, 121A, 120B, 121B are each pivotably connected at one end to the respectively associated upper guide rail 130A, 130B and at the other end to the seat part assembly 10, e.g. to a cross tube 102 pivotably extending between the frame parts 100A, 100B of the seat part assembly 10 (or to another part of the seat part assembly 10) in such a way that by pivoting the pivoting elements 120A, 121A, 120B, 121B the height of the seat part assembly 10 can be changed along a height direction Z (perpendicular to the longitudinal direction X and transverse direction Y). In this case, a distance between the seat part assembly 10 and the base assembly 13 is changed.The height adjustment device 12 is thus configured to adjust a distance between the seat part assembly 10 and the floor assembly 13. To effect an adjustment, the height adjustment device 12 comprises (at least) one drive device 3 (with one or more drive motors).

[0058] The floor assembly, i.e. here the longitudinal adjustment device 13, supports the seat part assembly 10.

[0059] The vehicle seat 1 further comprises a control system 14 coupled to the drive device 3, which is configured to perform the following steps:

[0060] Activating the drive device 3 to effect an adjustment of the seat subassembly 10 and / or the backrest subassembly 11 relative to the floor assembly (here the longitudinal adjustment device 13);

[0061] Detecting at least one value of a parameter of the adjusting device 12 and / or the drive device 3 during the adjustment; and

[0062] Determining a weight acting on the vehicle seat 1, in particular on the seat part assembly 10, based on at least one value of the parameter detected during the adjustment.

[0063] The control system 14 is configured to detect a signal indicating that the detected at least one value of the parameter is faulty and, in response to the signal, to repeat the detection of the at least one value of the parameter of the adjustment device 12 and / or the drive device 3 and / or to discard the previously detected at least one value of the parameter.

[0064] For example, the signal indicates that the occupant sitting on vehicle seat 1 moved during the measurement. If, for example, a child is sitting on vehicle seat 1 and fidgets, this can significantly distort the measurement. These movements may, but do not necessarily, involve the seat occupant's own movements. Likewise, vehicle movements, which in turn affect the occupant and the vehicle seat, can lead to distorted measurement results. In such a case, as well as in other cases where a signal indicates an erroneous measurement, increased measurement accuracy is achieved by repeating and / or discarding the measurement. Furthermore, the control system 14 is configured (alternatively or additionally) to perform the following steps:

[0065] Activating the drive device 3 to adjust the distance between the seat part assembly 10 and the floor assembly 13 in a first direction R1;

[0066] Detecting a value of a parameter of the drive device 3 during adjustment in the first direction R1;

[0067] Activating the drive device 3 to adjust the distance between the seat part assembly 10 and the floor assembly 13 in a second direction R2 opposite to the first direction R1;

[0068] Detecting a value of the parameter of the drive device 3 during adjustment in the second direction R2; and

[0069] Determining a weight acting on the seat subassembly 10 based on the detected values ​​of the parameter.

[0070] In the present case, the control system 14 is configured, for example, to detect whether the vehicle seat 1 and / or a seat occupant sitting thereon moves in the first direction R1 and / or in the second direction R2 due to a further force application, in particular a force application independent of the height adjustment device 12 and / or the drive device 3, during the detection of the at least one value of the parameter of the height adjustment device 12 and / or the drive device 3, preferably in such a way that an analysis of a current profile can be or is taken into account, in particular wherein, upon detection of a movement due to a further force application, the detection of the at least one value of the parameter of the height adjustment device 12 and / or the drive device 3 is repeated and / or the previously detected value of the parameter is discarded.

[0071] According to Fig. 1, an adjustment in the first direction R1 increases the distance between the seat subassembly 10 and the base assembly 13, while an adjustment in the second direction R2 decreases the distance between the seat subassembly 10 and the base assembly 13. Only a minimal adjustment path is required to determine the weight, e.g., a few mm in relation to the distance between the seat subassembly 10 and the base assembly 13, so that the measurement is either unnoticeable or barely noticeable to a seat user.

[0072] Optionally, the measurement can be performed multiple times, e.g., three times in succession, and an average weight value is determined. This can further increase accuracy.

[0073] The drive device 3 can be activated at different adjustment speeds and has a minimum and a maximum adjustment speed. The control system 14 is configured to activate the drive device 3 at the minimum adjustment speed in the first direction R1 and then in the second direction R2, or alternatively at an adjustment speed that is lower than the maximum adjustment speed. Thus, the weight measurement is barely noticeable or not noticeable at all to a seat occupant.

[0074] In this case, the parameter is an electrical parameter, namely the current intensity through the supply line of at least one drive motor 31 of the drive device 3. Alternatively or additionally, the applied power can also be used as a parameter. The current intensity corresponds to a respective torque (of the drive motor or motors) of the drive device 3. Depending on the size of the acting weight, e.g. by a passenger, a greater or smaller torque must be applied by the drive device 3 for an adjustment, e.g. by a predetermined adjustment path. Therefore, a predetermined relationship between the current intensity (generally the parameter) and the acting weight (possibly depending on the respective current adjustment position of the height adjustment device 12) can be used by the control system 14 to determine the weight.By performing the measurement in both adjustment directions R1, R2, inaccuracies that have different effects in the various directions can be calculated, e.g. by an (optionally weighted) averaging of weight values ​​determined separately for the two directions R1, R2. Inaccuracies due to friction, tolerances, wear and the like can be calculated using empty measurements when vehicle seat 1 is unoccupied. For example, the difference between a current strength (generally: value of the parameter) in an empty downward measurement and an occupied downward weight measurement is calculated and then multiplied by a first factor in order to determine a weight in the measurement during the downward adjustment.Furthermore, the difference between a current (generally: parameter values) for an occupied weight measurement upwards and an empty measurement upwards is calculated and then multiplied by a second factor to determine the weight in the measurement for the upward adjustment. The first factor and the second factor can be different or the same. The weight is then determined, for example, based on the sum of the two weight values.

[0075] The current intensity (in general: the value of the parameter) for a given direction can be determined as an average value over a range of travel. Optionally, the start-up of the drive motor can be excluded.

[0076] The parameter can also specify, for example, a maximum speed reached during adjustment, an adjustment path covered within a certain time or an adjustment time required for a certain adjustment path.

[0077] The predetermined relationship is stored, for example, in a storage medium 140. The relationship can be a model that assigns a value of an acting weight to each possible current value. Because these relationships depend on the adjustment direction in the example shown, the model also assigns a value of an acting weight to each possible current value with respect to an adjustment in the first direction R1 and with respect to an adjustment in the second direction R2, independently of one another. And because these relationships also depend on the adjustment position in the example shown, the model assigns a value of an acting weight to each possible current value for all possible setting positions of the height adjustment device 12. The model can comprise a LUT and / or a trained machine learning model.

[0078] To create the LUT and / or the training data for the machine learning model, test masses (e.g., 0 kg, 10 kg, 20 kg, 40 kg, and 80 kg, optionally with finer subdivisions) with various known weights can be placed on the seat subassembly 10, and the parameter values ​​(particularly at multiple adjustment positions) can be determined as described above. This allows a table of factors to be determined that assigns a weight value to each parameter value (e.g., the current) for each adjustment position. This table can be stored in the storage medium. Interpolation can be performed between any two table entries.

[0079] In order to correct for changes in efficiency and due to friction, etc., the control system 14 is designed to regularly perform calibration runs. For this purpose, the control system 14 is configured to record the values ​​of the parameter for calibration purposes when no weight is acting on the vehicle seat 1. A camera 4 (or another recording device such as a radar) is aimed at the vehicle seat 1 in order to record the size and position or the like of a passenger sitting on the vehicle seat 1 in camera images. The camera 4 is directly or indirectly communicatively connected to the control system 14, such that the control system 14 receives data on the seat occupancy of the vehicle seat 1 from the camera 4. This data can be in the form of the recorded images or in the form of previously evaluated information on weight, position, or the like.By combining the determined weight with information on height and position, seat occupancy can be recorded particularly precisely. A weight that was incorrectly determined, for example, due to an offset seating position, can also be corrected in this way. For this purpose, a correction table can be stored in the storage medium, which assigns correction factors to different seating positions (e.g., further forward, further back). Since occupant cameras are increasingly being installed in modern vehicles, such a measure is particularly easy to implement. The control system 14 is designed to receive the seat occupancy data based on the camera images, e.g., via an interface provided for this purpose.

[0080] The exemplary design of the height adjustment device 12 is explained in more detail below.

[0081] The frame parts 100A, 100B of the seat part assembly 10 are connected to one another at a rear end via the cross tube 102. The cross tube 102 is pivotally mounted (in this example) on the frame parts 100A, 100B and supports the associated rear pivot elements 121A, 121B.

[0082] In a front area, a seat pan 101 is arranged on the frame parts 100A, 100B to form a seat surface of the seat part assembly 10.

[0083] In the illustrated embodiment, the drive device 3 of the height adjustment device 12 is arranged, for example, on the rear pivot element 121A on the side of the guide rail pair 130A, 131A, as can be seen from Fig. 2 and 3 in conjunction with Fig. 4. The drive device 3 is designed as a spindle drive and serves to introduce an adjusting force into the pivot element 121A, so that by pivoting the pivot element 121A, the pivot elements 120A, 121A, 120B, 121B can be pivoted as a whole and the seat part assembly 10 can thereby be adjusted in its height position, i.e. the distance between the seat part assembly 10 and the base assembly 13 is adjusted. At a set seat height, the seat part assembly 10 is held in position on the pivot element 121A via the drive device 3.For this purpose, the drive device 3 is designed to be resilient enough to absorb and dissipate forces acting on the seat part assembly 10.

[0084] Referring now to Figs. 2 to 4, the drive device 3 has a spindle 30 which is pivotally connected at one end to the associated guide rail 130A via a bearing element.

[0085] The pivoting element 121A is coupled to an attachment connected to the guide rail 130A and is pivotably mounted on the guide rail 130A via a bearing pin.

[0086] With a threaded shaft 300 having an external thread, the spindle 30 extends substantially perpendicularly from the end connected to the guide rail 130A. An adjusting gear 32 is operatively connected to the spindle 30 such that, by driving the adjusting gear 32, the spindle 30 can be adjusted longitudinally along a longitudinal extension direction L, in order to change the length of an end of the spindle 30 pivotally mounted between the adjusting gear 32 and the guide rail 130A, thereby introducing an adjusting force into the pivot element 121A and thus adjusting the distance between the seat subassembly 10 and the base assembly 13.

[0087] The adjusting gear 32 has a spindle nut and a drive element in the form of a drive worm, which meshes with external teeth of the spindle nut via worm gearing. The drive element is driven by a drive motor 31, so that the spindle nut can be set in rotation by the drive motor 31. The spindle nut is threadably engaged with the external thread of the spindle 30 via an internal thread such that, upon rotation, the spindle nut rolls on the spindle 30 and is thereby adjusted longitudinally along the longitudinal direction L relative to the spindle 30.

[0088] Optionally, the height adjustment device 12 comprises a further drive motor 31, which can be arranged, for example, in a mirror image of the drive motor 31 on the rear pivot element 121B on the side of the guide rail pair 130B, 131B. This is illustrated schematically in Fig. 3. Based on the current values ​​of both drive motors, the acting weight can be determined particularly accurately.

[0089] The drive motors 31 are brushless direct current motors (BLDC motors) whose speed and torque can be adjusted with particular precision.

[0090] The adjusting gear 32 is pivotally mounted on the pivot element 121A. During an adjusting movement in which the length of the section of the spindle 30 extending between the adjusting gear 32 and the rail-side end is changed, the adjusting gear 32 can thus pivot on the pivot element 121A in order to compensate for a change in position of the pivot element 121A relative to the base assembly 13.

[0091] The drive motor 31 is pivotally mounted on the pivot element 121 A via the adjustment gear 32. During an adjustment movement of the pivot element 121 A, the drive motor 31 and also the adjustment gear 32 are thus moved together with the pivot element 121 A.

[0092] Fig. 5 shows, by way of example, an alternatively configured drive device for the vehicle seat according to Fig. 1, which has a drive motor 31 mounted on the seat subassembly 10, which drives a pinion 33 via a gear. The pinion 33 meshes with a curved toothed segment 34, which is attached to the upper guide rail 130A. Otherwise, the mode of operation is as described above.

[0093] Fig. 6 shows a method for the vehicle seat 1 , the method comprising the following steps:

[0094] Step S100: Activating the drive device 3 of the height adjustment device 12 of the vehicle seat 1 to adjust the distance between the seat part assembly 10 and the floor assembly 13 of the vehicle seat 1 in the first direction R1.

[0095] Step S101 : Detecting the value of the parameter (e.g. the current or the torque) of the drive device 3 during the adjustment in the first direction R1 .

[0096] Step S102: Activating the drive device 3 to adjust the distance between the seat subassembly 10 and the floor assembly 13 in the second direction R2 opposite the first direction R1. Step S103: Detecting the value of the parameter of the drive device 3 during the adjustment in the second direction R2.

[0097] Step S104: Determine a weight acting on the seat subassembly based on the detected values ​​of the parameter.

[0098] Optionally, the method begins periodically again at step S100, possibly with a (e.g. predetermined) delay between steps S104 and S100.

[0099] With regard to specific embodiments of the method, reference is made to the above information on the control system 14 to avoid repetition. The method may include corresponding method steps that correspond to the above-described functionality of the control system 14.

[0100] A computer program product comprising instructions is stored in the storage medium 140 which, when executed by the control system 14, cause the control system 14 to carry out the method described above.

[0101] The signal, in response to which the detection of the at least one value of the parameter of the adjustment device 12 and / or the drive device 3 is repeated and / or the previously detected at least one value of the parameter is discarded, can be obtained from the same measurement as the value(s) of the parameter from which the weight acting on the vehicle seat is calculated. Alternatively or additionally, the signal can be based on a different measurement and / or calculated from different sensor values.

[0102] Fig. 7 illustrates an example current profile of the drive device 3. Specifically, Fig. 7 shows a curve of the current intensity of one phase of the drive motor 31 of the drive unit 3 versus the adjustment travel. The position is illustrated on the x-axis as the number of motor revolutions. One complete revolution of the motor shaft corresponds to one motor revolution.

[0103] The diagram in Fig. 7 shows that the current fluctuates between a maximum and a minimum within one motor revolution, so that the current profile has a wavy structure over several motor revolutions. If the mean current is calculated for each motor revolution (or another moving window), these fluctuations per motor revolution can be subtracted. These mean values ​​are illustrated by a dashed line. However, it can be seen that the mean values ​​also have a variable profile. A repeating pattern can be seen which extends over a fixed number of motor revolutions and then repeats. Such a pattern is illustrated by vertical lines. This pattern results, for example, from the design of the drive device 3 and / or the adjustment unit, in particular from the design of the adjustment gear 32.

[0104] As can be seen in Fig. 7, the individual sections, each with a complete pattern, also differ from one another. For example, the pattern in the middle of the diagram has a higher overall average current than the pattern to its left and a lower average current than the pattern to its right. Furthermore, the maximum deviation in current within a pattern—i.e., the difference between the lowest and highest current values ​​within a pattern—can vary between individual sections. This difference is shown as a vertical double arrow for the middle pattern in Fig. 7, for example.

[0105] The applied weight can be determined from the measured values ​​shown, e.g., by determining the weight from the average current intensity of a sample using a predetermined conversion rule (e.g., a LUT). For example, the conversion rule assigns a weight value to a current intensity value in each position of the height adjustment device 12.

[0106] The signal can also be calculated from the measured values ​​shown. For example, the signal is the difference between the lowest and highest current values ​​within the (same) pattern. Or the signal is the deviation between the values ​​of (direct or spaced) consecutive patterns. If, for example, the signal exceeds a predetermined threshold, the control system discards the measurement and repeats the measurement. The signal can indicate that a fluctuation in current exceeds a predetermined threshold, that a deviation from the mean current exceeds a predetermined threshold, that a slope of the mean current calculated over a current time window exceeds a predetermined threshold, and / or that the curve deviates from a reference curve (e.g., the reference curve has maxima at known positions).If a shifted arrangement of the maxima is detected, a positioning error is likely. The fluctuation is determined, for example, via a peak-to-peak fluctuation, for which a limit is stored, below which the measurement is classified as error-free. Furthermore, an RMS value can be determined, for example. Furthermore, a maximum slope of the mean value can be used. If this exceeds a specified limit, the measurement is classified as faulty.

[0107] The control system 14 comprises a computer-readable memory in which a model is stored with which at least one relationship is established between the weight acting on the vehicle seat 1, in particular on the seat part assembly 10, and the adjuster position and / or the value of the measured parameter (e.g. the current intensity of the drive motor, e.g. of one of several phases or the current intensities of all phases).

[0108] The control system 14 is configured to detect the signal by analyzing the current profile.

[0109] For example, the control system 14 is configured to perform an FFT, e.g., on the current intensity curve shown in Fig. 7. The signal can indicate the exceedance of a threshold value in a predefined frequency range. This makes it possible to detect whether frequencies that are absent or only minimally present in an error-free weight measurement are present at an amplitude that indicates an error. For example, all frequencies that deviate from the harmonics of the motor rotation are identified as faulty if they exceed a certain limit.

[0110] The signal can also be generated by comparing two empty measurements, with one of the empty measurements (i.e. without a passenger on the vehicle seat 1) being a reference measurement. In general, the signal can be generated by comparing it with a reference measurement. For this purpose, it can be checked whether the new measurement lies within a tolerance band around the previous measurement. When dimensioning the tolerance band, one or more input variables can be used, e.g. the temperature, the inclination of the vehicle seat 1 or the like. Furthermore, the signal can be obtained by querying a sensor (e.g. interior sensor) or an activatable or actuatable component (e.g. air conditioning of the vehicle seat 1 or on the vehicle seat 1, actuation of the door handle on the vehicle seat 1, actuation of the window lifter on the vehicle seat 1 - if such an actuation is detected but no increase in load is determined, an error is likely and is output).For example, if a seat occupancy sensor, camera 4, a seat belt buckle, or the like indicates that vehicle seat 1 is not occupied by a passenger, but rather by an object such as a bag, the control system 14 can discard the weight measurement. The control system 14 can also be configured to query such external sensors or the like only after it has already determined the measurement itself to be faulty. For example, a plausibility check of the weight measurement result is provided.

[0111] The signal can be a signal communicated externally to the control system, or alternatively, for example, a signal generated within the control system 14, e.g., as the result of a binary query (e.g., the signal is the value of a Boolean variable). The signal indicates, for example, that a target state deviates from an actual state, so that it can be concluded that at least one of the detected values ​​of the parameter is incorrect.

[0112] The control system 14 is configured, e.g., by means of appropriate programming, to detect that the at least one parameter value detected for weight measurement is incorrect, and, in response thereto, to repeat the detection of the at least one parameter value of the adjustment device 12 and / or the drive device 3 in order to calculate a weight therefrom and / or to discard the previously detected at least one parameter value, i.e., not to use it for weight measurement. The measurement can comprise an adjustment in one direction or in both directions R1, R2.

[0113] Optionally, the control system 14 outputs an error message if it detects that at least one of the recorded values ​​of the parameter is incorrect. If the control system 14 determines that significant deviations or changes are detectable, which, for example, indicate that the vehicle seat 1 has been replaced or removed and installed, which affects mechanical properties, it can output an error message. Furthermore, it can be provided that the control system 14 requests a standardization run of the adjustment device, in particular the height adjustment device 12, if it detects an incorrect measurement. For this purpose, the adjustment device is moved to an end stop and from there, for example, adjusted once over the available adjustment range. List of reference symbols

[0114] 1 vehicle seat

[0115] 10 Seat part assembly

[0116] 100A, 100B frame part

[0117] 101 Seat pan

[0118] 102 Cross tube

[0119] 11 Backrest subassembly 12 Height adjustment device

[0120] 120A, 120B Swivel element 121 A, 121 B Swivel element 13 Floor assembly (longitudinal adjustment device)

[0121] 130A, 130B Guide rail 131 A, 131 B Guide rail 14 Control system 140 Storage medium 2 Vehicle floor 3 Drive device 30 Spindle 300 Threaded shaft

[0122] 31 Drive motor

[0123] 32 variable speed gears

[0124] 33 pinions

[0125] 34 tooth segment

[0126] 4 Camera

[0127] L Longitudinal direction

[0128] R1 , R2 direction

[0129] X Longitudinal direction

[0130] Y transverse direction

[0131] Z Altitude direction

Claims

Claims 1. Vehicle seat (1 ) comprising: - a seat part assembly (10), - a backrest subassembly (11 ), - a floor assembly (13) supporting at least the seat part assembly (10) and - an adjusting device (12) for adjusting the seat subassembly (10) and / or the backrest subassembly (11) relative to the floor assembly (13) with a drive device (3), characterized by - a control system (14) coupled to the drive device (3) and configured to perform the following steps: o activating the drive device (3) to effect an adjustment of the seat subassembly (10) and / or the backrest subassembly (11) relative to the floor assembly (13); o detecting at least one value of a parameter of the adjustment device (12) and / or the drive device (3) during the adjustment;and o determining a weight acting on the vehicle seat (1), in particular on the seat part assembly (10), based on the at least one detected value of the parameter during the adjustment, wherein the control system (14) is configured to detect a signal indicating that the detected at least one value of the parameter is incorrect, and in response to the signal to repeat the detection of the at least one value of the parameter of the adjustment device (12) and / or the drive device (3) and / or to discard the previously detected at least one value of the parameter.; 2. Vehicle seat (1) according to claim 1, characterized in that the parameter is an electrical parameter, in particular a current, a voltage or a power and / or that the parameter indicates a torque and / or that the parameter indicates a maximum speed reached during the adjustment.

3. Vehicle seat (1) according to claim 1, characterized in that the parameter indicates an adjustment path covered within a certain time or an adjustment time required for a certain adjustment path.

4. Vehicle seat (1) according to one of the preceding claims, characterized in that the adjusting device (12) is a height adjusting device for adjusting a distance between the seat part assembly (10) and the floor assembly (13), wherein the control system (14) is designed to activate the drive device (3) for adjusting the distance between the seat part assembly (10) and the floor assembly (13) in one direction (R1).

5. Vehicle seat (1) according to claim 4, characterized in that the direction (R1) is a first direction (R1) and the control system (14) is further configured to carry out the following steps: o activating the drive device (3) to adjust the distance between the seat part assembly (10) and the floor assembly (13) in a second direction (R2) opposite to the first direction (R1); and o detecting a value of the parameter of the height adjustment device (12) and / or of the drive device (3) during the adjustment in the second direction (R2); wherein the control system (14) is configured to determine a weight acting on the seat part assembly (10) based on the detected values ​​of the parameter from the adjustments in both directions (R1, R2).

6. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to detect as the signal whether the vehicle seat (1) and / or an occupant sitting thereon moves due to a further force during the detection of the at least one value of the parameter of the adjusting device (12), in particular height adjusting device (12), and / or the drive device (3).

7. Vehicle seat (1) according to claim 6, characterized in that the further force application is a force application independent of the adjusting device (12) and the drive device (3).

8. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to detect the signal by analyzing a current profile.

9. Vehicle seat (1) according to one of the preceding claims, characterized in that the signal indicates that a desired state deviates from an actual state, so that It can be concluded that at least one of the recorded values ​​of the parameter is incorrect.

10. Vehicle seat (1) according to one of the preceding claims, characterized in that the signal indicates a fluctuation in a current intensity of the drive device, indicates a deviation from an average value of a current intensity of the drive device and / or indicates a gradient of an average value of a current intensity of the drive device formed over a running time window.

11. Vehicle seat (1) according to claim 10, characterized in that the current intensity is a phase current of a multi-phase drive motor (31) of the drive device (3).

12. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to apply an FFT to measured values, in particular to current intensities, in particular against time or the adjustment position, wherein the signal indicates the exceeding of a threshold value in a predetermined frequency range.

13. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to detect the signal by comparing an empty measurement of the current intensity and / or the weight without occupant with the weight from a previous empty measurement.

14. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to detect the signal by querying a sensor and / or the activation and / or position of an adjustable component.

15. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to detect the signal by comparing a curve of a current intensity against a position with a stored reference curve.

16. Vehicle seat (1) according to one of the preceding claims, as far as dependent on claim 5, characterized in that the control system (14) is designed to control the drive device (3) for a predetermined time and / or to be activated via a predetermined adjustment path in the first direction (R1) and in the second direction (R2).

17. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) has a storage medium (140) in which a model is stored which assigns a value of an acting weight to each possible value of the parameter.

18. Vehicle seat (1) according to claim 17, characterized in that the model assigns a value of an acting weight to each possible value of the parameter for several possible setting positions of the height adjustment device (12).

19. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to record the values ​​of the parameter for calibration when no weight acts on the vehicle seat (1).

20. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) is designed to receive data on a seat occupancy of the vehicle seat (1) from a detection device, in particular a camera (4).

21. Vehicle seat (1) according to one of the preceding claims, characterized in that the control system (14) comprises a memory in which a model is stored in a retrievable manner, with which at least one relationship is established between the weight acting on the seat part assembly (10) and the input values ​​of the adjuster position and the value of the measured parameter.

22. System comprising the vehicle seat (1) according to one of the preceding claims and one or the detection device, in particular the camera (4).

23. Method for determining a weight acting on a vehicle seat, in particular on the vehicle seat (1) according to one of claims 1 to 21, comprising the following steps: o activating (S100) a drive device (3) of an adjusting device (12) of the vehicle seat (1) for adjusting a seat part assembly (10) and / or a backrest part assembly (11) relative to a floor assembly (13) of the vehicle seat (1); o detecting (S101) at least one value of a parameter of the adjusting device (12) and / or the drive device (3) during the adjustment; and o determining (S104) a weight acting on the vehicle seat (1), in particular on the seat part assembly (10), based on the at least one detected value of the parameter during the adjustment, wherein a control system (14) detects a signal which indicates that the detected at least one value of the parameter is incorrect, and in response to the signal, the detection of the at least one value of the parameter of the adjusting device (12) and / or the drive device (3) is repeated and / or the previously detected at least one value of the parameter is discarded.

24. A computer program product comprising instructions which, when executed by one or more computers, cause them to carry out the method of claim 23.

25. A non-transitory computer-readable storage medium (140) having stored thereon instructions which, when executed by one or more computers, cause them to carry out the method of claim 23.

Images