DE19518410B4 - Device for detecting a motor vehicle equipment, in particular for recognizing a child seat in a motor vehicle, for temporarily immobilizing a passenger airbag - Google Patents

Abstract

Facility for recognizing a child seat (56) in a motor vehicle for temporary Immobilizing a passenger airbag (16), with the child seat a first transponder (24) having one in the motor vehicle arranged detection means (123) cooperates, the at Child seat recognition an immobilization signal to a control unit (14) of Passenger Airbags (16) triggers, characterized in that the detection device (12) via a Antenna (22) with a permanently installed second transponder (46) communicates, by the transponder (24) superimposed or displaced is.

Description

Facility for recognizing a motor vehicle equipment, in particular for recognizing a child seat in a motor vehicle, for temporary Immobilizing a passenger airbag

It is known to use retention means in motor vehicles, the for the case of an accident the vehicle occupant the greatest possible safety should offer. Such retention means are, for example, airbags, belt tensioners and other facilities. The function of the retention means is in an accident, a kinetic energy of the vehicle occupants absorb within a short time, without the vehicle occupants too high delay values are exposed. The retention means should be within the shortest possible time Time trigger. known manner The motor vehicles usually have a driver and a Passenger airbag. Control units are used to control the airbags. the dependent the occurrence of an accident generate a triggering pulse for the airbags. in this connection is disadvantageous that the Airbags independent of an assignment of the front seats of the motor vehicle at a corresponding Cause accident. For example, if a child seat is mounted on the front passenger seat, would the Passenger airbag also trigger. As it is known, the child seat, for example, depending the age of a child to be transported, either in or opposite To mount the direction of travel would, in the event that the child seat is installed opposite to the direction of travel when triggering the Airbags the child seat against the backrest of the passenger seat be accelerated, so that for a Infant present in the child seat is a significant risk of injury. This is known from the RESEARCH DISCLOSURE 64 / February 1994, to equip the child safety seat with a transponder equipped with a in the motor vehicle arranged detection device cooperates. Once the transponder in the receiving area of the detection device arrives, an immobilization signal to a control unit of the passenger airbags triggered become.

Farther it is known to install safety devices in motor vehicles, which are intended to prevent the unauthorized use of motor vehicles. For this purpose, for example, with a fixed installed in the motor vehicle Recognition device cooperating transponder used. The transponder is usually in the ignition key of the motor vehicle housed and can one of the Detektorseinrich device emitted Receive question code signal and a corresponding to the respective Motor vehicle emit a coordinated response code signal. About one Comparison of the question code signal with the response code signal may be a Access authorization to the motor vehicle can be detected.

Out DE 44 09 971 A1 Transponder transmission from the child seat to the motor vehicle is known, wherein the transmission results in that an airbag associated with the passenger seat on which the child seat is located is deactivated.

Out EP 0 650 869 A1 a method and apparatus for detecting a rear-facing child seat is known. For this an electromagnetic signal is used.

Advantages of the invention

The inventive device for detecting a motor vehicle equipment, in particular for detecting a child seat in a motor vehicle, for temporarily immobilizing a passenger airbag with the features mentioned in claim 1 has the advantage that in a simple manner an absolutely intrinsically safe detection of a child seat and a dependent thereon control the control unit of the passenger airbag is possible. Characterized in that the detection device cooperates with a fixedly arranged in the passenger seat first transponder, which is superimposed or displaced by a second arranged on the child seat transponder, a completely secure detection of the arrangement of a child seat on the passenger seat is possible. As soon as the first, fixedly arranged transponder interacts with the recognition device, the absence of a child seat is detected. As soon as the first transponder is superimposed or displaced by the second transponder, the recognition device can detect the arrangement of a child seat and immobilize the control device of the front passenger airbag accordingly. Moreover, this makes it possible, with appropriate arrangement of the second transponder on the child seat to distinguish between a triggering and a non-triggering function of the passenger airbag in the presence of the child seat. For this purpose, arranged on the child seat second transponder is preferably arranged such that when installing the child seat in the direction of travel of the motor vehicle, the second transponder does not superimpose or displace the first transponder. With a correspondingly modified installation of the child seat, in particular when installed opposite to the direction of travel child seat, however, superimposed or displaced the second transponder superimposed on the first transponder, so that the detection means a corresponding immobilization signal to the control unit of the passenger Air can trigger bags. By using well-known and simple design, to do without its own energy source transponders, the device according to the invention can be realized without much effort. In addition to the basic equipment of a child seat with the transponder retrofitting existing child seats with a transponder is preferably possible. For this purpose, a corresponding transponder, for example in a form attachable by means of a film, can be supplied as an optional extra upon delivery of a motor vehicle. This separate transponder can be attached to the child seat with simple means, so that interaction with the recognition device provided in the motor vehicle or the permanently installed transponder becomes possible.

Further advantageous embodiments of the invention will become apparent from the rest in the dependent claims mentioned features.

drawings

The Invention will be described below in embodiments with reference to FIG associated Drawings closer explained. Show it:

1 a block diagram of a device for detecting a child seat;

2 a block diagram of a device for detecting a child seat according to a second embodiment variant;

3 a block diagram of a device for detecting a child seat according to a third embodiment;

4 a schematic side view of a motor vehicle seat and

5 a schematic plan view of a motor vehicle seat.

description the embodiments

1 shows a block diagram of a total with 10 designated, known per se device for detecting a child seat assembly on a passenger car seat of a passenger. The device 10 has a recognition device 12 that with a control unit 14 which is a trigger signal for a passenger airbag 16 can provide. The recognition device 12 has a control circuit only indicated here 18 , by means of which the provision and processing of the signals to be explained is carried out. In the context of the present description is intended to the specific structure of the control circuit 18 will not be discussed further, it being understood that the control circuit 18 for signal processing and processing corresponding voltage levels, amplifier stages, modulation and / or demodulation stages, memory levels, driver stages, etc. contains. The individual components of the control circuit 18 are preferably controlled by means of a microprocessor.

An input or output 20 the recognition device 12 is with an antenna permanently installed in the vehicle 22 connected. The antenna 22 is hereby preferably integrated in the seat surface of the passenger seat. The recognition device 12 works over the antenna 22 with a movable transponder 24 together, which is attached to a child seat which can be arranged in the front passenger seat. The transponder 24 can here be integrated in the child seat or arranged as an accessory to the child seat. The transponder 24 has a transmitting and receiving device not shown here in detail, for example in the form of an antenna and a rechargeable energy storage to provide a corresponding transmit power. The structure and operation of a transponder are well known and will not be explained in detail here.

In the 1 shown device 10 performs the following function:
During operation of the motor vehicle, not shown, the detection device 12 set in function via a switch, also not shown. This commissioning can preferably be combined with the starting of the motor vehicle by a corresponding control signal to the control circuit 18 the recognition device 12 is given. The control circuit 18 In turn, a so-called pre-drive check phase causes the device 10 , This is at the input or output 20 a question code signal provided via the antenna 22 is sent out. At the moment when no answer code signal arrives on the question code signal, for example because of the transponder 24 is not arranged on the passenger seat of the motor vehicle, provides the control circuit 18 a ready signal for the controller 14 ready. The control unit 14 is thus in a standby state, providing a trigger signal for the passenger airbag 16 in case of an accident. Thus, the function of the passenger airbag 16 guaranteed in an accident situation.

In the event that a child seat is mounted in the passenger seat, this is done via the antenna 22 radiated question code signal from the transponder 24 receive. The receiving device of the transponder 24 receives the question code signal and performs it a demodulation circuit of the transponder 24 to. The question code signal is compared with a code stored in a memory means. If the question code matches the stored code, a response code signal is modulated and transmitted by the transponder 24 the antenna 22 sent. For processing the question code signal and sending the response code signal, the energy transmitted with the question code signal is used. The question and answer code signals are preferably generated on the basis of HF, so that only extremely low transmission powers are necessary. The for generating the transmission power of the transponder 24 necessary energy can be transmitted via the RF question code signal from the antenna 22 on the transponder 24 be transmitted. The transponder 24 thus does not need its own energy source.

That of the transponder 24 provided response code signal is transmitted through the antenna 22 the control circuit 18 the recognition device 12 fed. The moment a response code signal arrives, the recognition means 12 detects the presence of a child seat on the front passenger seat of the motor vehicle. The control circuit 18 now provides a control signal for the controller 14 the passenger airbag 16 ready, which the STEU ergerät 14 blocked. Thus, in the event of an accident, the controller 14 no trigger signal to the front passenger airbag 16 provide. This avoids that arranged on the passenger seat of the motor vehicle child seat by the triggering passenger airbag 16 can be pushed against the backrest of the passenger seat. A risk of injury to a child in the child seat is thus avoided.

That in the 1 Block diagram shown served only for the basic explanation of the device according to the invention. The concrete structure of the control circuit 18 as well as the transponder 24 can be done by means of well-known electronic components, the explained function must be ensured. Furthermore, the installation location of the antenna 22 and the transponder 24 be chosen arbitrarily. The installation must only be such that when arranged on the passenger seat child seat, the transponder 24 in the effective range of the antenna 22 located. The transmission and reception of the antenna 22 and the transponder 24 are matched to one another so that only an exchange of the question code signal and the response code signal can take place when the child seat is arranged on the front passenger seat. For example, if the child seat is in a trunk of the motor vehicle, the transmission and reception services are not sufficient for communication.

In the 2 an advantageous embodiment of the child seat recognition by means of a transponder is shown. Same parts as in 1 are provided with the same reference numerals. In the embodiment shown here, the motor vehicle, not shown, has a so-called immobilizer 26 , at the first input or output 28 a first antenna 30 connected. The antenna 30 works with a transponder 32 together. By means of the portable, preferably arranged in the ignition key of a motor vehicle transponder 32 is over the antenna 30 realized in a well-known manner an immobilizer of the motor vehicle. The immobilizer 26 that has a corresponding control circuit 34 has, communicates via the antenna 30 with the transponder 32 by exchanging a question code signal and a response code signal and thus recognizes the access authorization of the transponder 32 owning, in the example so the owner of the ignition key driver. After performing a comparison of the response code signal and a stored expected response code signal, the immobilizer outputs 26 a corresponding signal to a here indicated bus line 36 , The bus line 36 For example, serves as a diagnostic bus for appropriately connected equipment of the motor vehicle. This can for example be an electronic engine control 38 , the control unit 14 for controlling the front passenger airbag 16 as well, here with the dashed line 40 merely indicated, be further control devices of the motor vehicle. In the normal function of the immobilizer 26 can via the transponder 32 and the antenna 30 a function of the electronic engine control 38 blocked or released. As a result, the aforementioned immobilizer or anti-theft device of the motor vehicle is realized.

According to the solution according to the invention, the control circuit has 34 additionally the in 1 designated control circuit 18 , The control circuit 18 can here be constructed as a completely separate control circuit, but can also according to another example on common, already existing components of the control circuit 34 fall back, so that duplications of components can be largely avoided. The immobilizer 26 has a second input or output 42 to which the antenna 22 connected. The antenna 22 works with the transponder 24 together. To avoid repetition, the operation of the control circuit 18 , the antenna 22 and the transponder 24 on the already too 1 referenced explanations.

According to the in 2 shown embodiment can be very beneficial to an existing immobilizer in a motor vehicle 26 be used for a child seat recognition. Because the control unit 14 for the passenger airbag via the bus line 36 with the immobilizer 26 that is, with its control circuits 34 respectively 18 may be in the absence or presence of a response code signal of the transponder 24 the control unit 14 in the already in

1 explained way blocked or released. Due to the basically same functions or signal processing sequences of the immobilizer on the one hand and the child seat recognition on the other hand, the immobilizer 26 be exploited for this dual function in a simple and cost-effective manner. Only by the provision of a second input or output 42 , the antenna 22 and a possible modification of the control circuit 34 so that these are the functions of the control circuit 18 can perceive the dual function of the immobilizer 26 , that is, the additional child seat recognition, be realized on a passenger seat.

In the 3 Another variant of a child seat recognition is shown. The illustration is only schematic, wherein like parts as in the preceding figures provided with the same reference numerals and are not explained again. In the embodiment shown here is a so-called base unit 44 provided that the detection device 12 as well as the control unit 14 for the passenger airbag 16 united together. The basic device 44 is with the arranged in the passenger seat antenna 22 connected. Inside the passenger seat is a first, permanently installed transponder 46 arranged. In the initial state, the base unit communicates 44 over the antenna 22 with the fixed transponder 46 , so that an exchange of question code signals or response code signals can take place. The transponder 46 provides here a specific, fixed response code signal, which from the antenna 22 received and to the detection device 12 or the control unit 14 is passed on. About the control circuit 18 that will be from the transponder 46 analyzed response code signal, that is, compared with a stored expected code and found that no child seat occupancy of the front passenger seat occurs. Accordingly, the controller 14 be put in the already mentioned state of readiness, that is, in a possible accident, a trigger signal is given to the passenger airbag.

The transponder installed in the passenger seat 46 can by the child seat assigned transponder 24 displaced or superimposed. This repression is in the 3 schematically by a displacement means indicated here only for clarity 48 realized. This means, in the event that a child seat is positioned in the passenger seat, that the transponder 24 in place of the permanently installed transponder 46 occurs and in turn with the base unit 44 over the antenna 22 communicated. On the over the antenna 22 emitted question code signal receives the recognition device 12 now another, namely the transponder 24 radiated response code signal. This in turn is done by means of the control circuit 18 analyzed. Due to the now applied response code signal of the transponder 24 recognizes the base unit 44 in that a child seat is arranged on the passenger seat. This will be for the controller 14 the passenger airbag provided a blocking signal, so that in the event of an accident, the passenger airbag does not trigger.

By the in 3 shown device 10 is an absolutely intrinsically safe detection of the arrangement of a child seat on the front passenger seat possible. This intrinsically safe detection can influence the release behavior of the front passenger airbag by activating or deactivating it. Due to the fact that the base unit 44 In any case, that is, regardless of the occupancy of the passenger seat, with a child seat communication with a transponder, either with the transponder 46 or the transponder 24 , performs a continuous functional test and child seat recognition is given. This is the security against the in the 1 and 2 explained variants of the device 10 further improved. By means of the permanently installed transponder 46 quasi an ongoing function monitoring of the detection device 12 , Once there is no communication between the detection device 12 and the transponder 46 If there is either a defect in one of the devices before or instead of the transponder 46 communicates the recognizer 12 now with the transponder 24 , whereupon the - already mentioned - switching of the control unit 14 he follows.

In the 4 and 5 is that in the 3 explained principle illustrated by the schematic representation of a passenger seat and a child seat. In 4 is a common with 50 designated passenger seat shown. The passenger seat 50 has a seat cushion 52 and a backrest 54 , On the representation of the optionally hinged connection of the backrest 54 with the seat cushion 52 was omitted for reasons of clarity. Inside the seat cushion 52 is the antenna 22 arranged. The antenna 22 is here in an area of the seat cushion 52 arranged below the backrest 54 lies. In the backrest 54 is the permanently installed transponder 46 arranged. The transponder 46 is here directly above the antenna 42 located so that between the antenna 22 and the transponder 46 only a small, from the distance of the seat cushion 52 to the backrest 54 given distance exists. In the in 4 As shown, the base unit communicates 44 over the antenna 22 with the transponder 46 , so that on non-occupancy of the passenger seat 50 is detected with a child seat.

In the 4 Dashed is a child seat 56 indicated. The child seat 56 For example, has a seat 58 as well as supporting and / or retaining skids attached thereto 60 , One of the runners 60 has a backrest on her 62 the seat shell 58 opposite end 64 the transponder 24 , The transponder 24 For example, this may be the same in the skid 60 be integrated or in addition, for example by means of a sensor film, on the underside of the runner 60 be attached. When using the child seat as intended 56 this will be in the direction of the indicated arrow 66 in the passenger seat 50 arranged. Here comes the skid 60 with her end 64 in between the seat cushion 52 and the backrest 54 existing gap, so that the transponder 24 the transponder 46 shields and in turn into the reception area of the antenna 22 arrives. On the presentation of additional existing attachments of the child seat 56 in the passenger seat 50 For example, by means of a restraining belt was omitted for reasons of clarity. Is the child seat 56 in its default installation position, the base unit communicates 44 ( 3 ) over the antenna 22 with the transponder 24 so that the base unit 44 - As already explained - prevents the triggering of the passenger airbag. Above the transponder 24 can on or in the skid 60 For example, an additional shielding device, such as a metallic foil, be provided, which is a communication of the base unit 44 with the transponder 46 at the in 4 shown installation position of the child seat 56 safely prevented.

On the basis of in 5 schematically shown plan view of the front passenger seat 50 , where here the child seat 56 is arranged such that the backrest 62 not in, but opposite to the direction of travel is, it is clear that the the transponder 24 having skid 60 with her end 64 from the backrest 54 the passenger seat 50 points away. As a result, a displacement or superimposition of permanently installed transponder 46 in the backrest 54 locked out. In the event that the child seat 56 in the in 5 is shown, the base unit communicates 44 over the antenna 22 with the transponder 46 , so that the release of the passenger airbag is not prevented.

Through the interaction of the antenna 22 with the transponders 46 respectively 24 Thus, every variant of the occupancy of the passenger seat 50 in a simple manner detectable. The proven and reliable system of a transponder identification makes it possible to easily realize a contactless and therefore relatively tolerance-insensitive child seat recognition. By means of a special skid, which in the 4 and 5 has shown structure, any child seat can be retrofitted. Thus, already in circulation vehicles can be retrofitted with the system easily. For newly manufactured vehicles here can the antenna 22 and the transponder 46 already be provided, which by its mass production and use only insignificantly higher costs, which also due to the 2 described double utilization of an existing immobilizer 26 can be minimized.

Of course, the invention is not limited to the exemplary embodiments illustrated in the figures. So can the arrangement of the antenna 22 or the transponder 46 or 24 be chosen differently. In addition, by means of a movable transponder 24 also the detection of other, that is, not related to a child seat recognition automotive equipment possible. For example, the transport of large or bulky items may be mentioned here.

Claims (13)

Device for recognizing a child seat ( 56 ) in a motor vehicle for temporarily immobilizing a passenger airbag ( 16 ), wherein the child seat a first transponder ( 24 ), which is arranged with a detection device ( 123 ) which, in the case of child seat recognition, generates an immobilization signal to a control unit ( 14 ) of the front passenger airbag ( 16 ), characterized in that the recognition device ( 12 ) via an antenna ( 22 ) with a permanently installed second transponder ( 46 ) communicating through the transponder ( 24 ) is superimposed or displaceable. Device according to claim 1, characterized in that the antenna ( 22 ) in a seat cushion ( 52 ) of a passenger seat ( 50 ) of the motor vehicle is arranged. Device according to one of the preceding claims, characterized in that the transponder ( 24 ) in the child seat ( 56 ) is integrated. Device according to one of the preceding claims, characterized in that the transponder ( 4 ) subsequently to the child seat ( 56 ) is attachable. Device according to one of the preceding claims, characterized in that the transponder ( 24 ) is a self-adhesive sensor film. Device according to one of the preceding claims, characterized in that the detection device ( 12 ) Part of an immobilizer ( 26 ) of the motor vehicle. Device according to one of the preceding claims, characterized in that the control of the control unit ( 14 ) via one with the immobilizer ( 26 ) connected diagnostic bus line ( 36 ) of the motor vehicle. Device according to one of the preceding claims, characterized in that the immobilizer ( 26 ) via a first input or output ( 28 ) a first antenna ( 30 ) for an anti-theft transponder ( 32 ) and via a second input and output ( 42 ) the second antenna ( 22 ) for the Device according to one of the preceding claims, characterized in that the immobilizer ( 26 ) a control circuit ( 34 ), which performs a dual function for theft prevention and child seat recognition. Device according to one of the preceding claims, characterized in that the transponder ( 46 ) in a backrest ( 54 ) of the passenger seat ( 50 ) is installed. Device according to one of the preceding claims, characterized in that the transponder ( 24 ) on a runner ( 60 ) of the child seat ( 56 ) is arranged. Device according to one of the preceding claims, characterized in that the transponder ( 24 ) asymmetrically to the child seat ( 56 ) is arranged. Device according to one of the preceding claims, characterized in that the transponder ( 24 ) at one end ( 64 ) of the skid ( 60 ), which is a backrest ( 62 ) of the child seat ( 56 ) is turned away.