Device for determining the angle of inclination and / or the position of a vehicle seat element in relation to the vehicle floor

Abstract

Device for determining the inclination angle and / or position of a vehicle seat element (3) with respect to the vehicle floor (4), comprising a vehicle seat (1) with at least one seat surface (2) and a backrest (3) attached thereto, comprising a first sensor (6) configured as a six-axis IMU sensor and comprising acceleration and gyroscopic sensors, and attached to the vehicle seat element (3), comprising a second sensor (7) which determines the inclination of the vehicle relative to a horizontal and is attached to the vehicle floor (4), comprising an angle and / or position calculation unit (8) configured to determine a first angle (Θ s(Acc.) ) of the vehicle seat element (3) relative to the horizontal by means of the acceleration sensors of the first sensor (6) and a second angle (Θ s(Gyro)) of the vehicle seat element (3) relative to the horizontal by means of the gyrosensors of the first sensor (6), with an angle and / or position estimation unit (9) which is designed to be derived from the first (Θ s(Acc.) ) and the second angle (Θ s(Gyro) ) using a Kalman filter (9a) and / or a complementary filter (9b) to determine the angle of inclination (Θ) s ) - and / or to estimate the position, and with an inclination angle and / or position calculation unit (10) which is designed, from the difference between the inclination angle (Θ s ) and the inclination (Θ v ) of the vehicle the tilt angle (Θ s(relative) ) the vehicle seat backrest (3) to determine.

Description

[0001] A vehicle seat typically consists of at least a seat cushion and a backrest. A headrest, armrests, or other seat components may also be part of the vehicle seat, usually attached to the backrest or seat cushion in a sliding manner. All components of a vehicle seat that serve to support a part of the body of a person sitting in the seat will be referred to as vehicle seat components in the following. The position of a seat component in a vehicle, particularly its angle of inclination or its position relative to the vehicle's longitudinal axis or floor, should be known to enhance passenger comfort, for example, to allow for motorized adjustment of the angle of inclination and / or position according to a predefined setting. Furthermore, the backrest of the front passenger seat should not obstruct a large screen in the rear.In addition, the airbag control unit requires information on seat element inclination and / or position in order to calculate the opening force of an airbag in an emergency.

[0002] Accelerometers can be used, but their use is limited due to dependencies on gravity and high sensitivity in noisy scenarios (e.g., occupant damping, driving on uneven roads).

[0003] US 9,610,862 B2 describes an occupant support detection system comprising an occupant support including a seat base configured to couple to a floor in such a way as to move back and forth along a longitudinal axis with respect to the floor, and a seat back coupled to the seat base and configured to extend upward from the seat base in such a way as to pivot about an axis with respect to the seat base. A support alignment unit is provided, comprising a floor alignment accelerometer coupled to the floor in a fixed position with respect to the floor and configured to measure and output accelerations with respect to the floor's gravity, a seat back accelerometer coupled to the seat back in such a way as to move with it and configured to measure and output accelerations with respect to the seat back's gravity, and a support motion control unit.which is coupled to the occupant support and the support alignment unit and is configured to calculate a floor inclination angle using accelerations output from the floor alignment accelerometer, an actual seatback angle using accelerations output from the seatback accelerometer, and a set seatback angle using the floor inclination angle and the actual seatback angle.

[0004] US 10,059,232 B2 describes an occupant support system comprising a vehicle seat including a seat base and a backrest coupled to the seat base to move upwards relative to the seat base, a pedestal designed to couple the vehicle seat to a vehicle floor for forward and backward movement relative to the floor, and a manual memory system designed to provide means for stepless adjustment of a longitudinal position of the vehicle seat relative to the floor without the use of driven motors in response to the application of a force exerted on the vehicle seat by the user, and for locking the vehicle seat in a stored position when the vehicle seat moves into the stored position.The manual memory system of the occupant support system may include a position sensor unit coupled to the vehicle seat for detecting a position of the vehicle seat relative to the floor, a locking unit coupled to the base for moving between a locked arrangement in which the movement of the vehicle forwards and backwards is blocked, and a released arrangement in which the vehicle seat is free to move relative to the floor, and a computer designed to provide means for receiving the position of the vehicle, as detected by the position sensor unit, which determines when the vehicle seat is in the stored position and instructs the longitudinal locking unit to block the movement of the vehicle seat relative to the floor when the vehicle seat is in the stored position.

[0005] US Patent 10,245,976 B2 describes a controller and interface for a vehicle seat.

[0006] US 10,427,553 B2 describes a seat motion system comprising a seat with a seat base designed to move on the floor of a vehicle, and a seat back coupled to the seat base to move relative to the seat base, a motion unit coupled to the seat configured to allow a user to move the seat, and a monitoring unit that couples the seat and the motion unit and is configured to provide means of detecting the user's intent, positioned at a distance from the seat, to cause the motion unit to move the seat in response to contact with a predetermined part of the seat with a predetermined force by the user, so that the seat is adjusted by the user while maximizing the ergonomic interaction between the driver and the seat.The monitoring unit can include one or more sensors coupled to at least one of the seat undersides, a backrest integrated into the seat back, and a headrest integrated into the seat back. The one or more sensors can include a force sensor and an accelerometer.

[0007] US Patent 9,925,892 B2 describes a vehicle seat motion system comprising a vehicle seat with a seat base and a backrest coupled to the seat base, wherein the vehicle seat is capable of extending upward from a vehicle floor into a variety of vertical positions, and wherein the vehicle seat is capable of being moved forward and backward along the vehicle floor into a variety of longitudinal positions. It provides a remote interface unit, a sensor unit coupled to the vehicle seat for detecting an arrangement of the vehicle seat relative to the vehicle floor, and an actuator unit comprising a longitudinal actuator coupled to the vehicle seat and capable of varying a longitudinal position of the vehicle seat relative to the vehicle floor, an angular actuator coupled to the backrest and capable of varying an angular position of the backrest relative to the seat base, and a seat height actuator.which is coupled to the vehicle seat and is capable of varying the vertical position of the vehicle seat relative to the vehicle floor, and includes a control unit designed to provide means to cause the actuator unit, in response to receiving a signal from the remote interface unit, to move the vehicle seat relative to the vehicle floor, and to cause the vehicle seat to assume a predetermined vertical position relative to the vehicle floor corresponding to a longitudinal position of the vehicle seat detected by the sensor unit, thus maximizing occupant comfort and safety. The sensor unit can be coupled to the control unit and designed to detect the longitudinal position of the vehicle seat relative to the vehicle floor, the vertical position of the vehicle seat relative to the vehicle floor, and the angular position of the backrest relative to the vehicle floor.

[0008] DE 10 2016 221 507 A1 describes an adjustable vehicle seat with a seat base having a seat surface and a seat back having a backrest surface, wherein sensors are provided in the seat base and / or in the seat back which detect forces, pressures and / or movements exerted by a person sitting on the vehicle seat and then emit a signal which is characterized in that a control device is provided which detects the signals emitted by the sensors and controls actuators provided in the vehicle seat for adjusting the seat base and / or the seat back or components thereof in order to adjust the vehicle seat.

[0009] US Patent 5,975,637 A describes a vehicle seat adjustable for seat position adjustment, comprising a seat section that is movable at least longitudinally, a backrest attached to the seat section and adjustable in its inclination relative to the seat section, and an adjustable headrest attached to the backrest and incorporating a head cushion. For the purpose of automatically adjusting the headrest correctly to a seat setting made by the seat user, a volume-variable fluid reservoir, communicating with a filling and draining device, is integrated into the head cushion. This reservoir is designed such that the front surface of the reservoir is moved forward when the volume increases and retracted when the volume decreases. A control unit regulates the amount of fluid added to or removed from the reservoir depending on the seat setting.The control unit determines the storage capacity using parameters of the seat and backrest settings and sends a corresponding control signal to the filling and draining device, whereby the storage capacity and the headrest height relative to the backrest can be read from a characteristic map stored in the control unit with the parameters of the seat and backrest settings supplied by sensors.

[0010] US 8,296,099 B2 describes a vehicle tilt detection device comprising: a load sensor having at least one of the support sections on which a vehicle seat is supported to detect a load acting on the support section for which the load sensor is provided; a load detection part that detects a partial load value of the load exerted on the seat based on an output of the load sensor and outputs a detected load value; a first contiguous part that indicates a relationship between a detected unoccupied load value output when a load is placed on the seat from the unoccupied load section and a front-to-back tilt angle of the vehicle; an unoccupied seat determination part that determines an unoccupied state in which no load is placed on the seat when the detected load value output by the load detection part is less than the determination value of an unoccupied seat;and a calculation section for the front and rear tilt angles, which calculates the front and rear tilt angles corresponding to the detected load value output by the load detection section based on the first contiguous part when the unoccupied seat determination section determines the unoccupied state. Two load sensors may be provided on two of the said support sections, the two support sections being arranged at the rear of the seat such that they are spaced apart from each other, and the load detection section sums the outputs of the two load sensors to detect the partial load value of the load applied to the seat.

[0011] US 2017 / 0349061 A1 describes an adjustment system for adjusting a vehicle seat, wherein the adjustment system comprises a vehicle seat sensor unit configured to detect an arrangement of the vehicle seat relative to a vehicle floor and to generate sensor signals, and comprises a computer configured to receive the sensor signals, determine an initial arrangement of the vehicle seat relative to the vehicle floor using the sensor signals, and is configured to determine, based on the sensor signals, when a user has sat in the vehicle seat, determine when a predetermined time has elapsed after the user has sat in the vehicle seat, and determine an adjustment profile for the movement of the vehicle seat after the predetermined time period has elapsed based on the sensor signals and predetermined criteria, and comprises a comfort adjustment unit configured tothat it receives one or more commands from the computer assigned to the adjustment profile to move the vehicle seat through various positions corresponding to the adjustment profile.

[0012] US 9,815,387 B2 describes a vehicle seat comprising a seat base designed to be attached to a floor in order to slide along the floor, a backrest coupled to the seat base, and a power-operated means for repositioning the vehicle seat by moving the seat base along the floor in response to a user applying a force to the backrest or seat base while seated in the vehicle seat, such that the vehicle seat is repositioned to allow passenger boarding or to accommodate a passenger location preference, without requiring the user to manually overcome all the frictional and gravitational forces that resist the movement of the vehicle seat.

[0013] US Patent 9,994,125 B2 describes a vehicle comprising a seat, a first sensor connected to the seat for detecting a seat angle, and a processor that is communicatively connected to the first sensor and the seat and configured to output a control signal to correct the seat angle if the seat angle is outside a predetermined range of values. The seat may include a backrest and a seat cushion, and the seat angle may be an angular relationship between the backrest and the seat cushion. The first sensor may be connected to the backrest and configured to detect an angle of the backrest.The vehicle may further include a second sensor, wherein the second sensor is connected to the seat cushion and configured to detect an angle of the seat cushion, and wherein the processor may further be configured to calculate the seat angle based on the angle detected by the first sensor and the angle detected by the second sensor.

[0014] DE 10 2022 214 322 A1 relates to a method for robustly determining the spatial position of a vehicle interior element that is adjustable by an electric adjustment motor, comprising the steps of: - determining a first value of a predetermined position and / or orientation specification of the element relative to the vehicle interior based on an internal sensor of the adjustment motor; - redundantly determining at least a second value of the same position and / or orientation specification of the element independently of the motor, based on measurement data from at least one external reference sensor located in the vehicle interior without a direct mechanical connection to the adjustment motor; - comparing the first value determined in relation to the motor with the second value determined independently of the motor and determining any deviation between them;-Plausibility check and / or correction of the first value and / or its engine-related determination algorithm depending on the determined deviation, before it is subsequently used for predetermined control processes in the vehicle interior.;

[0015] DE 10 2017 203 636 A1 relates to a seating arrangement comprising a seat, a backrest, and a plurality of sensors operatively connected to the seat and / or backrest to detect the seating state of a seated occupant. A control unit is electrically connected to the plurality of sensors and at least one actuator. The control unit is programmed to receive an input from the plurality of sensors that is characteristic of the seating state of the seated occupant. The seating state of the seated occupant is compared with stored seating states of previous occupants to determine that the seated occupant is a previous occupant.

[0016] DE 10 2020 125 879 A1 relates to an electrical system comprising a mounting surface, a component configured for connection to and movement relative to the mounting surface, and / or an orientation sensor configured to determine the component's orientation relative to the mounting surface. The orientation sensor may include a first sensor (e.g., a magnetometer, accelerometer, gyroscope, etc.) connected at least indirectly to the mounting surface, and a second sensor (e.g., a magnetometer, accelerometer, gyroscope, etc.) connected to the component for movement. The orientation sensor may include an electronic control unit.The electronic control unit can be configured to compare initial information from the first sensor with subsequent information from the second sensor to determine the orientation of the component relative to the mounting surface.

[0017] The object of the invention is to provide an improved device for determining the angle of inclination and / or the position of a vehicle seat element in relation to the longitudinal axis of the vehicle or the vehicle floor.

[0018] The problem is solved by a device according to claim 1; advantageous embodiments and further developments are specified in the dependent claims.

[0019] Accordingly, a device for determining the inclination angle and / or the position of a vehicle seat element with respect to the vehicle floor is formed by a vehicle seat with at least one seat surface and a backrest attached to it by means of a pivot axis and movable about the pivot axis, the vehicle seat elements being movably attached to a rail on the vehicle floor in the longitudinal direction of the vehicle, with a first sensor designed as a six-axis IMU sensor and having accelerometers and gyroscopic sensors for the three spatial directions, and which is attached to the vehicle seat element, with a second sensor which determines the inclination of the vehicle with respect to a horizontal and is attached to the vehicle floor, with an angle and / or position calculation unit which is connected to and configured with the first sensor.to determine a first angle and / or a first position of the vehicle seat element relative to the horizontal using the acceleration sensors of the first sensor and a second angle and / or a second position of the vehicle seat element relative to the horizontal using the gyroscopic sensors of the first sensor, with an angle and / or position estimation unit connected to and configured with the angle and / or position calculation unit, to estimate the tilt angle and / or position from the first and the second angle and / or the first and the second position using a Kalman filter and / or a complementary filter, and with a tilt angle and / or position calculation unit connected to and configured with the second sensor and the angle and / or position estimation unit,to determine the tilt angle and / or position of the vehicle seat element relative to the vehicle floor from the difference between the tilt angle and / or position of the vehicle seat element relative to the horizontal estimated by the angle and / or position estimation unit and the tilt of the vehicle relative to the horizontal determined by the second sensor.

[0020] To calculate the angle or position of the vehicle seat element, a 3-axis accelerometer and a 3-axis gyroscope are implemented alongside a 3-axis accelerometer to make the system robust against various driving scenarios. Furthermore, a complementary filtering technique is applied to merge the data and leverage the advantages of both sensors. Additionally, a Kalman filter technique is being evaluated to incorporate the control signal into the system, making the calculated seat angle or position more robust against various noisy and complex scenarios (for example, passenger movements while accelerating the vehicle uphill).

[0021] The use of a combination of acceleration- and gyroscope-based measurements, along with sophisticated sensor fusion techniques, can significantly improve the accuracy of estimating seat movements and inclinations, especially in noise-prone environments.

[0022] In a further development, the device is formed with a vehicle seat control unit connected to the tilt angle and / or position calculation unit, and with a vehicle seat element actuator connected to the vehicle seat control unit, wherein the vehicle seat control unit is configured to adjust the tilt angle and / or the position of the vehicle seat element.

[0023] In a further development, the vehicle seat element actuator is connected to a vehicle seat element locking mechanism.

[0024] Its purpose is to activate a locking mechanism of an occupant support, thus preventing movement of a vehicle seat element relative to the vehicle floor. This action is triggered in response to the signal received from the seat controller.

[0025] The angle and / or position calculation unit, the angle and / or position estimation unit, and the tilt angle and / or position calculation unit can each be part of a vehicle seat movement control unit. In a further development of the device, a headrest is arranged on the vehicle seat backrest, with the first sensor being located between the axis and the headrest on the vehicle seat backrest. Advantageously, the first sensor can be located closer to the axis than to the headrest on the vehicle seat backrest.

[0026] The invention is described in more detail below with reference to an exemplary embodiment and the figures. These figures show... Fig. 1 a schematic representation of a vehicle seat and Fig. 2 a schematic representation of a device for determining the inclination angle of a vehicle seat backrest in relation to the longitudinal axis of the vehicle.

[0027] The Fig. Figure 1 shows a vehicle seat 1, which comprises a seat surface 2 and a backrest 3 attached to it by means of a pivot axis 5 and movable about the pivot axis. A headrest 3a is mounted on the backrest 3 or is formed as part of the backrest 3. The vehicle seat 1 is movably mounted on a rail on a vehicle floor 4 in the longitudinal direction of the vehicle. The vehicle seat 1 can have electric motors to adjust the seat with respect to its position in the vehicle and also to adjust the positions of the seat surface 2 and the backrest 3. For this purpose, a memory can be provided in a control unit in a known manner, in which person-related settings are stored and automatically used for adjustment upon recognition of the person. The vehicle seat 1 could also have other vehicle seat elements – not shown – such as armrests.

[0028] A first sensor 6 is attached to the backrest 4 of the vehicle seat 4. According to the invention, this sensor is designed as a six-axis IMU sensor and includes acceleration sensors and gyroscopes for each of the three spatial directions. A second sensor 7 is attached to the vehicle floor 4. This sensor determines the vehicle's inclination relative to a horizontal plane, thus providing vehicle data.

[0029] In the Fig. Section 2 now schematically illustrates some units and their interaction with which the angle of inclination Θ is determined. s(relative) The position of a vehicle seat backrest 3 in relation to the vehicle longitudinal axis 14 can be determined and, if necessary, the vehicle seat backrest 3 can be actuated by means of an actuator 13 and adjusted according to a desired tilt angle.

[0030] An angle and / or position calculation unit 8 is provided, which is connected to the first sensor 6 and is configured to calculate a first angle Θ.s(Acc.) the vehicle seat backrest 3 relative to the horizontal, which were obtained by means of the acceleration sensors of the first sensor 6, with a first angle and / or position calculation subunit 8a and a second angle Θ s(Gyro) to determine the angle of the vehicle seat backrest 3 relative to the horizontal, which was obtained by means of the gyro sensors of the first sensor 6, with a second angle and / or position calculation unit 8b.

[0031] In the embodiment described here, only the calculation of the inclination angle of a vehicle seat backrest 3 as a vehicle seat element is described in detail; however, all conceivable inclinations and positions of other vehicle seat elements can be determined in the same way using the units described.

[0032] Furthermore, an angle and / or position estimation unit 9 is provided, which is connected to the angle and / or position calculation unit 8 and is designed from the first Θ s(Acc.) and the second angle Θ s(Gyro) The inclination angle Θ is determined using a Kalman filter 9a and / or a complementary filter 9b. s to estimate. This is done using known formulas.

[0033] An inclination angle and / or position calculation unit 10 is connected to the second sensor 7 and the angle and / or position estimation unit 9 and is configured from the difference between the inclination angle of the vehicle seat backrest 3 relative to the horizontal estimated by the angle and / or position estimation unit 9 and the inclination Θ determined by the second sensor 7. v the vehicle's angle of inclination Θ relative to the horizontal. s(relative)to determine the position of the vehicle seat backrest 3 in relation to the vehicle longitudinal axis 14. It would also be possible to determine the position.

[0034] This value is stored in memory 11 and made available to another memory 11a.

[0035] Data from a human-machine interface 15 can also be entered and further processed in the additional memory 11a and in the angle and / or position estimation unit 9. For example, a desired inclination of the vehicle seat backrest 3, as requested by a person in the vehicle seat 1, can be entered.

[0036] The device of Fig. 2 comprises a vehicle seat control unit 12 which is connected to the tilt angle and / or position calculation unit 10 and to a vehicle seat backrest actuator 13, wherein the vehicle seat control unit 12 is configured to determine the tilt angle Θ s(relative)to adjust the vehicle seat backrest 3, in particular by means of an electric motor.

[0037] The angle and / or position calculation unit 8, the angle and / or position estimation unit 9 and the inclination angle and / or position calculation unit 10 can be parts of a vehicle seat movement control unit, which is formed in particular with a microcontroller or more generally with a computer.

[0038] A headrest 3a can be arranged on the vehicle seat backrest 3, wherein the first sensor 6 is arranged between the axis 5 and the headrest 3a on the vehicle seat backrest 3. In particular, the first sensor 6 can be arranged closer to the axis 5 than to the headrest 3a on the vehicle seat backrest 3.

Claims

[1] Device for determining the angle of inclination and / or the position of a vehicle seat element (3) in relation to the vehicle floor (4), with a vehicle seat (1) having at least one seat surface (2) and a backrest (3) attached to it by means of a pivot axis (5) and movable about the pivot axis, forming vehicle seat elements, wherein the vehicle seat (1) is movably attached to a rail on the vehicle floor (4) in the longitudinal direction of the vehicle, with a first sensor (6) designed as a six-axis IMU sensor and comprising accelerometers and gyroscopic sensors for the three spatial directions, and which is attached to the vehicle seat element (3), with a second sensor (7) that determines the inclination of the vehicle relative to a horizontal and is attached to the vehicle floor (4), with an angle and / or position calculation unit (8) connected to and configured with the first sensor (6) to determine a first angle (Θ s(Acc.) ) and / or a first position of the vehicle seat element (3) relative to the horizontal by means of the acceleration sensors of the first sensor (6) and a second angle (Θ s(Gyro) ) and / or to determine a second position of the vehicle seat element (3) relative to the horizontal using the gyrosensors of the first sensor (6), with an angle and / or position estimation unit (9) which is connected to and formed with the angle and / or position calculation unit (8), from the first (Θ s(Acc.) ) and the second angle ( Θs(Gyro) ) and / or the first and second positions using a Kalman filter (9a) and / or a complementary filter (9b) to determine the angle of inclination (Θ s ) and / or to estimate the position, and with an inclination angle and / or position calculation unit (10) which is connected to and configured with the second sensor (7) and the angle and / or position estimation unit (9), from the difference between the inclination angle (Θ) estimated by the angle and / or position estimation unit (9) s ) and / or the position of the vehicle seat element (3) relative to the horizontal and the inclination (Θ) determined by the second sensor (7). v ) of the vehicle relative to the horizontal the angle of inclination (Θ s(relative) ) and / or to determine the position of the vehicle seat element (3) in relation to the vehicle floor (14). [2] Device according to claim 1 comprising a vehicle seat control unit (12) connected to the tilt angle and / or position calculation unit (10), and a vehicle seat element actuator (13) connected to the vehicle seat control unit (10), wherein the vehicle seat control unit (10) is configured to determine the tilt angle (Θ s(relative) ) and / or to adjust the position of the vehicle seat element (3). [3] Device according to claim 2, wherein the vehicle seat element actuator (13) is connected to a vehicle seat element locking mechanism. [4] Device according to claims 1 to 3, wherein the angle and / or position calculation unit (8), the angle and / or position estimation unit (9) and the tilt angle and / or position calculation unit (10) are parts of a vehicle seat movement control unit. [5] Device according to one of the preceding claims, wherein a headrest (3a) is arranged on the vehicle seat backrest (3), the first sensor (6) being arranged between the axis (5) and the headrest (3a) on the vehicle seat backrest (3). [6] Device according to claim 5, wherein the first sensor (6) is arranged closer to the axis (5) than to the headrest (3a) on the vehicle seat backrest (3).

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