DE102013216549B3 - Vehicle seat for motor vehicle, has component and another component movable relative to former component, where base module is fixed with respect to former component in stationary manner and emits output signal - Google Patents

Abstract

The vehicle seat (1) has a component and another component movable relative to the former component. A base module (20) is fixed with respect to the former component in a stationary manner and emits an output signal. A transponder (50) is fixed with respect to the latter component in a stationary manner. The transponder receives the output signal and emits a response signal. The base module determines a signal transit time between the emission of the output signal and the reception of the response signal. The transponder is designed as Radio frequency identification module. An independent claim is included for a method for detecting the position of a vehicle seat.

Description

The invention relates to a vehicle seat with position detection with the features of the preamble of claim 1.

The invention also relates to a method for position detection with the features of claim 6.

State of the art

From the DE 10 2010 026 214 A1 is a generic vehicle seat known. The vehicle seat comprises a longitudinal adjuster with a lower rail which can be fastened to a vehicle structure and an upper rail guided displaceably in the longitudinal direction, and with position detection. For this purpose, the longitudinal adjuster comprises a sensor which roughly detects the longitudinal position of the vehicle seat relative to the vehicle structure, in particular the sensor detects whether the vehicle seat is in a forward position or in a rearward position. The sensor is fixed to the vehicle seat with respect to the upper rail and thus movable relative to the vehicle structure. By means of electrical lines, the sensor is connected to a control unit.

From the DE 694 27 598 T2 For example, a method and apparatus for detecting a rear-facing child seat are known. It is detected whether a child seat is arranged in the rearward direction on a vehicle seat in order to prevent the triggering of an airbag in the event of a crash.

Also from the DE 694 18 137 T2 Such a method and apparatus are known.

In the WO 2007/036551 A1 are disclosed a conductive textile, an antenna and a vehicle seat. The antenna is formed from the conductive textile and arranged in the vehicle seat.

From the WO 2005/011439 A2 A passenger seat with a data memory and an associated reader emerge. In this case, the data memory is arranged on a component of the passenger seat and readable by means of an external reader.

From the EP 1 648 768 B1 are also such a passenger seat with a data storage and a corresponding reader known.

The EP 1 872 300 B1 discloses an RFID transceiver unit for a child seat recognition device. A transmitting antenna arranged in a vehicle seat generates a field of excitation. In response to the exciter field, an RFID transponder located in a child seat generates a transponder signal. A receiving antenna located in the vehicle seat receives the transponder signal as well as a jamming signal.

From the DE 10 2007 002 662 A1 For example, a vehicle seat adjusting device and a method for adjusting a vehicle seat are known. In this case, at least one position of the vehicle seat is provided, which is suitable for the use of a child seat.

task

The invention is based on the object to improve a vehicle seat of the type mentioned, in particular to ensure a position detection with increased resolution, while stationary in relation to the upper rail fixed electrical lines to avoid.

solution

This object is achieved by a vehicle seat with the features of claim 1 and by a method for position detection with the features of claim 6.

Advantageous embodiments, which can be used individually or in combination with each other, are the subject of the respective subclaims.

A generic vehicle seat with position detection comprises a first component and a relative to this second movable component. For example, the first component is a lower rail, and the second component is a longitudinal rail slidably guided therein in the longitudinal direction.

According to the invention, there are at least one base module fastened fixedly with respect to the first component, which emits an output signal, and at least one transponder fixed in relation to the second component, which receives the output signal and emits a response signal, wherein the base module receives the response signal and wherein the base module determines a signal transit time between transmission of the output signal and receipt of the response signal.

As a result, a position detection of the vehicle seat with relatively high resolution and relatively high accuracy can be achieved.

The base module preferably calculates a distance of the base module from the signal propagation time to the transponder. Alternatively, a separate arithmetic unit can be provided for the calculation of the distance.

Advantageously, the transponder is configured as an RFID module, ie as a radio frequency identification module. RFID modules are relatively inexpensive and have a low weight.

The transponder is particularly advantageously a passive RFID module. Thus, the transponder does not require its own power supply and thus also no connection of electrical lines.

Preferably, at least two base modules are provided, each base module having an antenna which serves to emit the output signal and to receive the response signal, and wherein the antennas of the base modules are arranged at a defined distance from each other. As a result, a two-dimensional position detection is possible.

According to an advantageous embodiment of the invention, the base module comprises a transmitter for emitting the output signal and a receiver for receiving the response signal.

Advantageously, the base module comprises a first memory, which can be connected to the receiver by means of a first switch, and a second memory, which can be connected to the receiver by means of a second switch.

According to the inventive method for detecting the position of a vehicle seat is provided that an output signal is transmitted from a base module, the output signal is received from a transponder, a response signal is emitted from the transponder after receiving the output signal, the response signal is received by the base module, wherein a Signal delay between the transmission of the output signal and reception of the response signal is determined, and wherein from the signal propagation time, a distance of the base module is calculated to the transponder.

The inventive method is applicable to manually adjustable vehicle seats as well as electrically or partially electrically adjustable vehicle seats.

Advantageously, the output signal is transmitted during a signal duration, upon receipt of the response signal during the signal duration, a first memory is loaded, and upon receipt of the response signal after the signal duration, a second memory is charged.

Preferably, the second memory at least approximately maintains its charge state upon receipt of the response signal during the signal duration, and the first memory at least approximately maintains its charge state upon receipt of the response signal after the signal duration.

To determine the signal propagation time, the charge of the first memory and the charge of the second memory are measured, and the signal propagation time is determined from the ratio of the charge of the second memory to the charge of the first memory.

Preferably, the signal duration is greater than the signal propagation time, whereby the measurement has a relatively high accuracy.

Figures and embodiments of the invention

In the following the invention is explained in more detail with reference to an advantageous embodiment shown in the figures. However, the invention is not limited to this embodiment. Show it:

1 : a schematic representation of a vehicle seat according to the invention,

2 : a schematic representation of the signal transmission between a base module and a transponder,

3 : a block diagram of a base module and

4 : the timing of a measuring cycle of the base module.

A vehicle seat 1 for a motor vehicle has a seat part 2 which is a seat frame 4 includes, and an attached, tilt-adjustable backrest 10 on.

The arrangement of the vehicle seat 1 Within the vehicle and its usual direction of travel define the directional information used below. In this case, a direction oriented perpendicular to the ground is referred to below as the vertical direction and a direction perpendicular to the vertical direction and perpendicular to the direction of travel is referred to below as the transverse direction.

By means of a Lehneneinstellers, which laterally on the vehicle seat 1 arranged, manually operated Lehneneinstellbeschlag 19 includes, is the backrest 10 tilt adjustable, that means the angle between the seat part 2 and the backrest 10 is adjustable. Alternatively, an electric drive is conceivable.

By means of a height adjuster is the height of the seat part 2 and present at the same time the backrest 10 of the vehicle seat 1 adjustable over the vehicle structure. To drive the Height adjuster is presently a manually operated drive device 7 intended. Alternatively, an electric drive is conceivable.

By means of a longitudinal adjuster which has two lower rails connected to the vehicle structure 5 as well as two with the vehicle seat 1 connected top rails 3 has, is the vehicle seat 1 longitudinally adjustable, that means the seat part 2 is together with the backrest 10 in the longitudinal direction, which corresponds approximately to the direction of travel, adjustable. This is each of the top rails 3 in each case one of the parallel longitudinally extending lower rails 5 slidably guided and by means of a locking device with the respective lower rail 5 lockable. By means of an unlocking bracket 16 the locking device is unlocked. Alternatively, an electric drive is also conceivable here.

The longitudinal direction is perpendicular to the transverse direction, but in the present case slightly inclined relative to the direction of travel, and thus also approximately perpendicular to the vertical direction.

The seat part 2 further comprises a seat cushion 11 , which is designed as a foam part. Also the backrest 10 is upholstered with a foam part and, like the seat cushion 11 covered with a cover. The seat cushion 11 and the foam part of the backrest 10 significantly increase the seating comfort for an occupant of the vehicle seat 1 ,

At the vertically upper end of the backrest 10 which is the seat part 2 is remote, is also a height adjustable and tilt adjustable headrest 18 appropriate.

On the vehicle structure, and thus stationary in relation to the lower rails 5 , is a detection unit 60 attached, which emits and receives signals in the form of electromagnetic waves. The detection unit 60 can also be directly on one of the lower rails 5 to be appropriate. In the present case, the detection unit comprises 60 two basic modules 20 , Each basic module 20 includes an antenna for transmitting and receiving electromagnetic waves. The detection unit 60 thus comprises two antennas, which are arranged at a defined distance from each other. The signals are transmitted through the air, so electrical lines are not required.

At the vehicle seat 1 There are three transponders in the present case 50 arranged, which record and answer electromagnetic signals. The transponders 50 In the present case, they are configured as passive RFID modules (Radio Frequency Identification) and do not require their own power supply and thus also no connection of electrical lines. The RFID modules draw the energy required for operation from that of the base modules 20 emitted electromagnetic waves.

For example, the base modules send 20 in advance and independent of the output signal 42 electromagnetic waves as an energy signal for powering the transponder 50 which buffer the absorbed energy in an internal energy storage. It is also conceivable that the base modules 20 immediately before the emission of the output signal 42 each send out an energy signal. It is also conceivable that the base modules 20 alternately an output signal 42 and send an energy signal. It is also conceivable that the base modules 20 only output signals 42 send and the transponder 50 Obtain the required energy from the output signals.

One of one of the base modules 20 the detection unit 60 emitted output signal 42 is doing by the transponder 50 recorded and by a response signal 44 answered. One from the transponder 50 sent response signal 44 is from the base module 20 receive. Temporally lies between the emission of the output signal 42 through the base module 20 and receiving the response signal 44 through the base module 20 a signal delay L. The base module 20 determines the signal propagation time L, ie the time difference between the transmission of the output signal 42 and receiving the response signal 44 , and calculates from this a distance A of the base module 20 to the transponder 50 ,

The duration of the response signal 44 is present equal to the duration of the output signal 42 corresponds in each case to a signal duration t1. Also different signal durations are conceivable.

In the present embodiment, the vehicle seat comprises 1 a first transponder 50 which is in a front area of the seat part 2 is arranged, a second transponder 50 which is in a rear area of the seat part 2 is arranged and a third transponder 50 which is in an upper area of the backrest 10 is arranged.

By measuring and calculating the individual distances of the two base modules 20 the detection unit 60 to the said three transponders 50 is the position and orientation of the vehicle seat 1 determinable. This means that the position of the longitudinal adjuster, the position of the height adjuster and the position of the Lehneneinstellers are with knowledge of the distances of the base modules 20 to the three transponders 50 determined.

The detection unit 60 Also includes an arithmetic unit, which the individual distances from each of the two base modules 20 to each of the three transponders 50 processed and from these distances the position of each transponder 50 determined two-dimensionally.

In the following, the principle for distance measurement based on a simplified embodiment of a vehicle seat 1 explained. According to this simplified embodiment, exactly one on the vehicle structure, ie stationary in relation to the lower rails 5 , fixed base module 20 and exactly one on the seat part 2 So fixed in relation to the top rails 3 , attached transponder 50 intended. A height adjuster is not provided.

By measuring and calculating the distance A between the base module 20 and the transponder 50 is thus the position of the longitudinal adjuster, ie the position of the vehicle seat 1 in the longitudinal direction, can be determined.

The basic module 20 includes a logic gate 22 , which is a first switch 30 , a second switch 34 and a transmitter 38 controls. With appropriate control by the logic gate 22 sends the transmitter 38 an output signal 42 out. There is also a microcontroller 24 provided, which with the logic gate 22 and with a measuring unit 26 communicated. The measuring unit 26 is presently designed as a voltage measuring unit.

The first switch 30 is electrically between a receiver 40 and a first memory 32 arranged. The second switch 34 is electrically between the receiver 40 and a second memory 36 arranged. The switches 30 . 34 are in the present case designed as transistors. A version as another electronic switch or as an electromechanical switch, in particular as a relay, is conceivable.

The stores 32 . 36 are in the present case designed as capacitors. It is also conceivable the memory 32 . 36 as capacitor-resistor elements, or as electronic counters, in particular with a microprocessor.

Is one of the switches 30 . 34 closed, there is an electrical connection between the receiver 40 and the memory concerned 32 . 36 , So in the present case between the receiver and a respective first electrode of the capacitor in question. The respective second electrodes of the capacitors are connected to ground. If the receiver 40 a response signal 44 receives, then arises in the receiver 40 an electric charge, which when the switch is closed 30 . 34 to the memory concerned 32 . 36 flows.

The measuring unit 26 is by means of signal lines to the first memory 32 and the second memory 36 connected. With appropriate control by the microcontroller 24 measures the measurement unit 26 the charge of a store 32 . 36 , In this case, the voltage applied between the electrodes of a capacitor voltage, and supplies the result to the microcontroller 24 ,

The basic module 20 performs the distance measurement constantly in repetitive measuring cycles. A measuring cycle comprises phases P1, P2, P3 and P4 described below. Alternatively, the base module leads 20 the measuring cycle only on request by a control unit or another module through.

In a first phase P1, the transmitter transmits 38 no output signal and the receiver 40 does not receive a response signal. The first switch 30 is open. The second switch 34 is open. The first store 32 is unloaded. The second memory 36 is unloaded. There is no measurement by the measuring unit 26 instead of.

At a start time t0, a second phase P2 begins. The transmitter 38 sends an output signal 42 out. The first switch 30 is closed. The second switch 34 is open. The first store 32 will be loaded as soon as the receiver 40 that from the transponder 50 sent answer signal 44 receives. The second memory 36 retains its state of charge. There is no measurement by the measuring unit 26 instead of.

After the signal duration t1, a third phase P3 begins. The transmitter 38 does not send an output signal. The first switch 30 is open. The second switch 34 is closed. The first store 32 retains its state of charge. The second memory 36 will be charged as long as the receiver 40 that from the transponder 50 sent answer signal 44 receives. There is no measurement by the measuring unit 26 instead of.

The phases P2 and P3 are repeated several times, here n / 2 times, where n is an even and positive number. The duration of both phases P2 and P3 is the same here and corresponds in each case to the signal duration t1. It is also conceivable that the duration of the phases P2 and P3 is different.

Thereafter, a fourth phase P4 begins. The transmitter 38 does not send an output signal. The first switch 30 is open. The second switch 34 is open. The first store 32 retains its state of charge. The second memory 36 retains its state of charge. The measuring unit 26 measures the charge of the storage 32 . 36 , in the present case, the voltages applied to the capacitors.

After completion of a measurement cycle follows a transitional phase in which the memory 32 . 36 unloaded, or reset.

This is followed by a next measurement cycle with the described phases P1, P2, P3 and P4. The timing of a measurement cycle of the base module 20 is the diagram in 4 removable.

If the transponder 50 has no response delay is the sought distance A of the base module 20 to the transponder 50 proportional to the signal delay L, ie to the time difference between the emission of the output signal 42 and receiving the response signal 44 ,

The signal delay L is from that of the measuring unit 26 measured charges of memory 32 . 36 , in this case from the voltages across the capacitors, can be determined.

The larger the ratio of the charge of the second memory 36 , the voltage at the second capacitor, to the charge of the first memory 32 , the voltage at the first capacitor is, the greater the signal propagation time L.

The signal duration t1 is to be selected such that the signal duration t1 is always greater than the signal propagation time L. If the transponder 50 has no response delay, ie immediately upon receipt of the output signal 42 the response signal 44 sends, so the signal delay L is proportional to the distance A. In the present case, the Einstellweg the vehicle seat 1 limited in the longitudinal direction. The maximum possible distance of the transponder 50 from the base module 20 corresponds to a maximum distance d. For the signal duration t1 to be selected, the following applies: t1> 2 d / c c = 299.710 km / s is the speed of light in air.

For an exemplary maximum distance d = 1 m, this yields: t1> 6.67 ns.

A real transponder 50 However, it has a response delay. The signal duration t1 is therefore greater to select by said duration of the response delay. The distance A is in this case not proportional to the signal propagation time L and can be determined for example by means of a characteristic curve.

The features disclosed in the foregoing description, the claims and the drawings may be of importance both individually and in combination for the realization of the invention in its various forms.

LIST OF REFERENCE NUMBERS

1

 vehicle seat

2

 seat part

3

 upper rail

4

 seat frame

5

 bottom rail

7

 driving means

10

 backrest

11

 seat cushions

16

 Entriegelungsbügel

18

 headrest

19

 Lehneneinstellbeschlag

20

 base module

22

 logic gates

24

 microcontroller

26

 measuring unit

30

 first switch

32

 first memory

34

 second switch

36

 second memory

38

 transmitter

40

 receiver

42

 output

44

 answer signal

50

 transponder

60

 detection unit

t0

 start time

t1

 signal duration

L

 Signal propagation time

n

 just positive number

A

 distance

d

 maximum distance

P1

 first phase

P2

 second phase

P3

 third phase

P4

 fourth phase

c

 Speed of light in air (not shown in the figures)

Claims (10)

Vehicle seat ( 1 ) with position detection, comprising a first component ( 5 ) and a relative to this movable second component ( 3 ), characterized in that at least one stationary with respect to the first component ( 5 ) fixed base module ( 20 ) is provided which an output signal ( 42 ) and that at least one stationary with respect to the second component ( 3 ) attached transponder ( 50 ) is provided, which the output signal ( 42 ) and a response signal ( 44 ), where the base module ( 20 ) the response signal ( 44 ) and wherein the base module ( 20 ) a signal transit time (L) between transmission of the output signal ( 42 ) and receipt of the response signal ( 44 ). Vehicle seat ( 1 ) according to claim 1, characterized in that the transponder ( 50 ) is designed as an RFID module. Vehicle seat ( 1 ) according to one of the preceding claims, characterized in that at least two base modules ( 20 ), each basic module ( 20 ) has an antenna which is used to transmit the output signal ( 42 ) and to receive the response signal ( 44 ), and wherein the antennas of the base modules ( 20 ) are arranged at a defined distance from each other. Vehicle seat ( 1 ) according to one of the preceding claims, characterized in that the base module ( 20 ) a transmitter ( 38 ) for transmitting the output signal ( 42 ) and a receiver ( 40 ) for receiving the response signal ( 44 ). Vehicle seat ( 1 ) according to claim 4, characterized in that the base module ( 20 ) a first memory ( 32 ), which by means of a first switch ( 30 ) with the receiver ( 40 ), and a second memory ( 36 ), which by means of a second switch ( 34 ) with the receiver ( 40 ) is connectable. Method for detecting the position of a vehicle seat ( 1 ), wherein an output signal ( 42 ) from a base module ( 20 ), the output signal ( 42 ) from a transponder ( 50 ), a response signal ( 44 ) of the transponder ( 50 ) after receiving the output signal ( 42 ), the response signal ( 44 ) from the base module ( 20 ), and wherein a signal transit time (L) between transmission of the output signal ( 42 ) and receipt of the response signal ( 44 ), and wherein from the signal delay time (L) a distance (A) of the base module ( 20 ) to the transponder ( 50 ) is calculated. Method according to claim 6, characterized in that the output signal ( 42 ) is emitted during a signal duration (t1), that upon receipt of the response signal ( 44 ) during the signal duration (t1) a first memory ( 32 ) and that upon receipt of the response signal ( 44 ) after the signal duration (t1) a second memory ( 36 ) is loaded. Method according to claim 7, characterized in that upon receipt of the response signal ( 44 ) during the signal duration (t1) the second memory ( 36 ) maintains its state of charge, and that upon receipt of the response signal ( 44 ) after the signal duration (t1) the first memory ( 32 ) maintains its state of charge. Method according to one of claims 7 to 8, characterized in that the charge of the first memory ( 32 ) and the charge of the second memory ( 36 ) and that from the ratio of the charge of the second memory ( 36 ) to the charge of the first memory ( 32 ) the signal transit time (L) is determined. Method according to one of claims 7 to 9, characterized in that the signal duration (t1) is greater than the signal propagation time (L).

Images