Vehicle and electrical circuit arrangement for detecting current seat occupancy in vehicle

Abstract

The invention relates to a vehicle, a wire harness and an electrical circuit arrangement for detecting a current seat occupancy in a vehicle. The electrical circuit arrangement (11) comprises a first occupancy sensor (8) in a first line (1) for a first seat of the vehicle and a second occupancy sensor (9) in a second line (2) for a second seat of the vehicle, the first occupancy sensor and the second occupancy sensor are used for generating ohmic resistance according to the occupancy states of the seats assigned to the first occupancy sensor and the second occupancy sensor, the first line (1) and the second line (2) are connected in parallel with each other and are used for being connected between a first connector (13) and a second connector (14) of a wiring harness (5) of the vehicle, and the first connector (13) and the second connector (14) are connected in parallel with each other. The circuit arrangement is configured to apply an electrical alternating signal between the first and the second connection (13, 14) and to measure an electrical measured value of an electrical variable in response to the electrical alternating signal.

Description

Field of the Invention

[0001] The present invention relates to a vehicle, a wiring harness, and an electrical circuit device for identifying the current seat occupancy in a vehicle. In particular, the present invention relates to a possibility of simplifying the hardware technology for differentially identifying the current seat occupancy in a vehicle. Background Art

[0002] In vehicles, thin-film sensors are sometimes used for seatbelt warnings. These thin-film sensors have pressure sensors that can cause a change in resistance when the seat assigned to the pressure sensor is occupied. Three sensors are used for seatbelt warnings for the second-row seats, and each sensor is connected to an airbag controller or another controller (ECU) or another evaluation unit using point-to-point connections. Due to the large number of wires, the plug connections are extremely large and expensive. In particular, the cost, weight, and structural space are limited due to the large number of wires. However, it is sometimes also desirable to be able to individually identify the seats that are respectively occupied, so it is not easily feasible to identify the entire row of seats as a whole. Summary of the Invention

[0003] Based on the above prior art, the object of the present invention is to mitigate or completely eliminate the above disadvantages.

[0004] According to the present invention, the above object is solved by an electrical circuit device for identifying the current seat occupancy in a vehicle.

[0005] The dependent claims illustrate preferred expansion schemes of the present invention.

[0006] The electrical circuit device can be arranged for use in a car, a transporter, a motorcycle, a truck, an aircraft and / or a ship. The electrical circuit device has a first occupancy sensor in a first (electrical) line for a first seat of the vehicle. Thus, the occupancy sensor is logically and in particular also spatially assigned to the first seat. In a corresponding manner, a second occupancy sensor is provided in a second (electrical) line for a second seat of the vehicle. The first line and the second line can be arranged parallel to each other. In other words, they can use the same first connector on the outside and the same second connector on the other side. The seat occupancy sensors are arranged to generate an electrical ohmic resistance according to the occupancy state of the seats assigned to them. For example, the seat occupancy sensors can reduce a previously relatively high ohmic resistance in response to the occupancy of the seats assigned to them. The first line and the second line (e.g., by plug contacts, solder pads, cut / clamp connections, etc.) are arranged to be connected between a first connector and a second connector of the vehicle's wiring harness. Thus, the electrical circuit device in particular has exactly two external electrical connectors, so that a third wire or other wires for connection to the used electronic controller can be dispensed with. The circuit device is now arranged to confirm an electrical alternating signal according to seat occupancy between the first and second connectors by means of corresponding electrical parameters (e.g., current, voltage, resistance, etc.). In other words, the electrical alternating signal applied between the first connector and the second connector shows an electrical characteristic parameter in response to the applied alternating signal according to the occupancy state or the response state of the occupancy sensor. The electrical parameter can for example represent the current flowing between the first connector and the second connector. Alternatively or additionally, the electrical alternating signal can represent the (complex) resistance measured between the first and second connectors. Alternatively or additionally, the alternating signal can find an electrical resistance related to the current direction, which resistance is provided for example by a non-linear electrical element (e.g., a diode). Thus, although information is determined only by electrical measurements at two connectors, various switching states can be identified.

[0007] The first line can have a first component in series with the first occupancy sensor, and / or the second line can have a second component in series with the second occupancy sensor. The first component and / or the second component can for example be constructed as a diode or a current direction-related resistor. Alternatively or additionally, the first component and / or the second component can have a variable impedance according to the frequency. Thus, when the characteristics of the two components are different, in particular the occupancy of the vehicle's seats can be determined by the alternating signal. For example, these components can be oriented differently and / or have different sizes from each other. According to which of the two components becomes electrically activated or "visible" due to seat occupancy, it can be determined by the alternating signal applied to the two connectors and with the aid of a predefined reference which seat occupancy sensor has been activated / occupied.

[0008] The first component can have a first capacitor and / or a first inductor and a first diode. Alternatively or additionally, this can apply to the second component. The first and second components do not have to have the same nature / type. If the first and second components are of the same type, they do not have to have the same dimensions. The two components can be oriented differently from each other as long as they have an impedance related to the direction of the current. Thus, a variety of possibilities are provided for encoding the activated occupancy sensors and identifying the activated occupancy sensors via the described electrical measurements.

[0009] Especially for the case where the component has a frequency-dependent impedance, it is possible to determine which occupancy sensor is currently activated / occupied based on a frequency-variable electrical alternating signal.

[0010] In order to be able to access another electrical seat occupancy sensor for determining another occupancy state of another seat, a third line can be connected in parallel with the first and second lines, and the above-described embodiments apply to this third line in a corresponding manner. In this case, it is only necessary to note that the determined electrical parameters are sufficiently characteristic for each occupancy state. In other words, in response to the alternating signal, the occupancy states must produce electrical parameters that are sufficiently spaced apart from each other. Alternatively or additionally, another line can also be connected in series with the first, second (and each additional) line. The third line can have a third occupancy sensor that is logically (especially also spatially) assigned to the third seat of the vehicle. It should be noted here that each series-connected line of the seat occupancy configuration has a finite resistance in order to be able to completely determine the occupancy state of the parallel-connected occupancy sensors through the joints. Therefore, in particular, it is not advisable to use a diode as the third component (if present). However, for example, two different resistances, especially a factor of 10 or 2 different, can ensure that a finite current is measured in any case as a response to the alternating signal, and the occupancy state within the vehicle is derived from this finite current. The complex resistance of the corresponding lines does not necessarily only differ numerically in order to be able to clearly determine the seat occupancy. The phase position of the electrical parameter relative to the electrical alternating signal can also be used as an indicator of the current seat occupancy.

[0011] Preferably, the electrical circuit arrangement can have an alternating voltage source and / or an electrical evaluation unit, which is configured to apply an electrical alternating signal between a first connection and a second connection. By means of electrical measurements, which can in particular be carried out automatically by the electrical evaluation unit, electrical parameters can be measured in response to the electrical alternating signal and the seat occupancy can be determined based on the electrical parameters and a predefined (in particular electrically complex) reference. Especially in a vehicle, the low-voltage vehicle electrical system is designed as a DC electrical system. Therefore, according to the invention, an alternating voltage is generated from a DC voltage (12 V, 24 V, 48 V or higher) if necessary, which causes a certain hardware expense (inverter) if necessary. However, the savings in cabling, the reduction in electrical connection complexity and the resulting weight reduction, volume reduction and overall cost reduction justify this possible additional expense, especially when a third row of seats or other rows of seats are added in a vehicle and their seat occupancy is automatically checked in the manner according to the invention.

[0012] According to a second aspect of the invention, a wiring harness having an electrical circuit arrangement according to the above-described embodiments is proposed. A first electrical conductor is guided to the first connection and a second electrical conductor is guided to the second connection. By means of these conductors of the wiring harness, the electrical circuit arrangement is connected electrically and in terms of information technology to the peripherals of the circuit arrangement inside the wiring harness. In particular, the occupancy state of the electrical circuit arrangement can be determined by means of the electrical measurements carried out as described above without additional electrical conductors. Even in the presence of additional occupancy sensors, the overall number of electrical conductors required can be significantly reduced, whereby the above-mentioned advantages can also be better utilized.

[0013] According to a third aspect of the invention, a vehicle is proposed which has an electrical circuit arrangement and / or a wiring harness according to the above-described aspects of the invention. With regard to the features, feature combinations and resulting advantages of the wiring harness according to the invention and of the vehicle according to the invention, reference is made to the above description in order to avoid repetition.

[0014] The core idea of the invention is to supplement and operate in an interleaved manner a seat occupancy sensor which is basically known in the prior art by adding non-linear electrical components (semiconductor components such as rectifier diodes and transistors, and optionally also capacitors and coils). When the dimensions are clearly suitable for a person skilled in the art, currents and / or voltages and / or resistances which can be sufficiently different electrically from one another can thus be measured for each seat occupancy state of a vehicle and can be clearly assigned to the seat occupancy situation based on a predefined reference.

[0015] Other details, features and advantages of the invention result from the following description and the drawings. Description of the Drawings

[0016] In the figures:

[0017] Figure 1 Shows a schematic top view of a vehicle according to the prior art;

[0018] Figure 2 Shows a circuit arrangement according to a first embodiment of the invention; and

[0019] Figure 3 Shows a circuit arrangement according to a second embodiment of the invention. Detailed Description

[0020] Figure 1 Shows a top view of a sedan as a vehicle 10, inside which, in the second row of seats, the occupancy states of three seats S1, S2, S3 are monitored by respective occupancy sensors 8, 9, 12 by means of an electrical circuit arrangement 11. Although a common ground wire is provided for the occupancy sensors 8, 9, 12, the respective positive leads cause a great deal of wiring effort in the wiring harness 5 and the plug connections 6 and the evaluation unit 4. Only in this way can the occupancy states be clearly assigned to the seats S1, S2, S3 in the prior art by means of an evaluation resistor or the current through the occupancy sensors 8, 9, 12.

[0021] Figure 2 Shows an electrical circuit arrangement according to the invention. A wiring harness 5 comprising two wires extends from an evaluation unit 4 which also serves as an AC voltage source to a plug connection 6. Here, a first electrical connector 13 and a second electrical connector 14 are provided, by means of which the device 11 can apply an electrical alternating signal to lines 1, 2, 3. In response to the application of the electrical alternating signal, the evaluation unit 4 can observe or measure a complex behavior which is clearly assigned to the seat occupancy between the first connector 13 and the second connector 14. In other words, the interconnection of the lines 1, 2, 3 responds with electrical parameters or characteristic parameters, and the evaluation unit can compare the electrical parameters or characteristic parameters with predefined entries in a reference (such as a look-up table, etc.) and can thus clearly assign them to the seat occupancy.

[0022] Figure 3 Shows from Figure 2Partial view of the electrical circuit device 11 taken therefrom, wherein the lines 1, 2, 3 are exemplarily designed by specific electrical resistors R1, R11, R2, R22, R3, R33, occupancy sensors 8, 9, 12 and a first member D1 in the form of a first diode and a second member D2 in the form of a second diode. The diodes have different orientations such that different half-waves flow through the resistors R1, R11 or R2, R22 when an alternating signal is applied. Thus, depending on the occupancy state, at any given moment, only one of the resistors R1, R11, R2, R22 is electrically active or electrically visible or electrically effective, and is either in series with the resistor R3 of the third line 3 or with the resistor R33 of said third line. In the state shown, it is assumed that the occupancy sensors 8, 12 are occupied while the occupancy sensor 9 is not. Thus, in the first half-wave of the electrical alternating signal, the resistor R11 in series with the resistor R33 should be measured at the joints 13, 14, and in the second wave of the alternating signal, the series circuit consisting of the resistor R2 and the resistor R33 should be measured. Conversely, if the third seat or the third occupancy sensor 3 is not occupied, the resistor R33 in the above group should be replaced by the resistor R3. The same applies accordingly to other seat occupancy situations.

[0023] List of reference numerals:

[0024] 1, 2, 3 Lines

[0025] 4 Evaluation unit

[0026] 5 Wiring harness

[0027] 6 Plug connection

[0028] 8, 9 Occupancy sensors

[0029] 10 Vehicle

[0030] 11 Electrical device

[0031] 12 Occupancy sensor

[0032] 13, 14 Joints

[0033] D1, D2 Members

[0034] R1, R11, R2, R22, R3, R33 Electrical ohmic resistors

[0035] S1, S2, S3 Seats

Claims

1. An electrical circuit arrangement for identifying the current seat occupancy in a vehicle (10), the circuit arrangement comprising: - a first occupancy sensor (8) in a first line (1) for a first seat (S1) of the vehicle (10) and - a second occupancy sensor (9) in a second line (2) for a second seat (S2) of the vehicle (10), wherein the first occupancy sensor and the second occupancy sensor are arranged to generate an electrical ohmic resistance in accordance with the occupancy state of the seat (S1, S2, S3) assigned to them, wherein, the first line (1) and the second line (2) are connected in parallel with each other and are arranged to be connected between a first connector (13) and a second connector (14) of a wiring harness (5) of the vehicle (10), wherein the circuit arrangement is arranged to apply an electrical alternating signal between the first connector (13) and the second connector (14) and to measure an electrical measurement value of an electrical parameter in response to the electrical alternating signal.

2. The electrical circuit arrangement according to claim 1, wherein, the first line (1) has a first component (D1) connected in series with the first occupancy sensor (8), and / or the second line (2) has a second component (D2) connected in series with the second occupancy sensor (9), the first component and / or the second component having an impedance, in particular a complex impedance, that is variable in accordance with - the direction of the current and / or - the frequency of the current.

3. The electrical circuit arrangement according to claim 1 or 2, wherein - the first component (D1) has a first capacitor and / or a first inductor or a first diode, and / or - the second component (D2) has a second capacitor and / or a second inductor or a second diode.

4. The electrical circuit arrangement according to any one of the preceding claims, wherein, the first component (D1) has a first diode, and the second component (D2) has a second diode, and the first diode (D1) and the second diode (D2) are oriented oppositely with respect to the first connector (13) and the second connector (14).

5. The electrical circuit arrangement according to any one of the preceding claims, wherein, the electrical alternating signal - has a positive half-wave and a negative half-wave, and / or - is variable in frequency.

6. The electrical circuit arrangement according to any one of the preceding claims, further comprising a third occupancy sensor (12), the third occupancy sensor being connected to the first line (1) and the second line (2) at a first pole and to the second connector (14) at a second pole.

7. A wiring harness having the electrical circuit arrangement according to any one of the preceding claims, the wiring harness comprising a first electrical conductor to the first connector (13) and a second electrical conductor to the second connector (14).

8. A vehicle comprising the electrical circuit arrangement according to any one of claims 1 to 6 or the wiring harness (5) according to claim 7.

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