VEHICLE DEVICE HAVING A BASE VEHICLE AND A SEAT UNIT

Abstract

A vehicle device comprising a base vehicle and a seat unit being releaseably connectable to the base vehicle is described. The base vehicle comprises an electronic control means and a vehicle-side wireless communication means, and the seat unit comprises at least one sensor, a battery, an electronic unit, and a seat-side wireless communication means. In order to provide the electronic control means of the base vehicle with the necessary information about the seat unit in an energy-saving manner, the electronic unit reads-out the status of the at least one sensor in a certain time-scheme and transmits a sensor related signal via the seat-side wireless communications means only if the status of the sensor changed since the previous read-out.

Claims

1. A vehicle device comprising: a base vehicle and a seat unit being releasably connectable to the base vehicle, wherein the base vehicle comprises an electronic control means and a vehicle-side wireless communication means connected to the electronic control means, and the seat unit comprises: a seat element; a sensor; an electronic unit comprising: (a) a timing means for generating time-spaced wake-up signals S(t); (b) a read-out means for reading out the sensor to retrieve values V(t) from the sensor; (c) a storage means; (d) a comparing means; (e) a seat-side wireless communication means adapted for wireless communication with the vehicle-side wireless communication means; and, a battery for supplying the electronic unit with electrical power, wherein: (i) the read-out means according to (b) reads out the value V(t) after having received a wake-up signal S(t) according to (a); (ii) the comparing means according to (d) compares the value V(t) according to (i) with a stored value V.sub.s stored in the storage means according to (c); (iii) the seat-side wireless communications means according to (e) sends out a signal representing the value V(t) if V(t)?V.sub.s and does not send out a sensor related signal if V(t)=V.sub.s; and, (iv) the value V(t) is stored as the new stored value V.sub.s if V(t)?V.sub.s.

2. The vehicle device according to claim 1, wherein the seat-side wireless communication means according to (e) sends out an alive-signal other than the signal representing the value V(t) according to (iii) if V(t)=V.sub.s.

3. The vehicle device according to claim 1, wherein the electronic unit of the seat unit has at least a first state and a second state, wherein the electrical power consumption in the first state is less than in the second state, and each wake-up signal S(t) of the timing means brings the electronic unit from the first state into the second state.

4. The vehicle device according to claim 2, wherein the electronic unit of the seat unit returns to its first state after having sent the alive-signal.

5. The vehicle device according to claim 1, wherein the vehicle-side wireless communication means and the seat-side wireless communication means define a bi-directional communication path.

6. The vehicle device according to claim 5, wherein the base vehicle sends out an acknowledgement signal to the seat unit after having received a signal according to (iv) from the seat unit.

7. The vehicle device according to claim 6, wherein the base vehicle does not send out an acknowledgement signal to the seat unit after having received an alive-signal from the seat unit.

8. The vehicle device according to claim 7, wherein the electronic unit of the seat unit returns to its first state after having received the acknowledgement signal.

9. The vehicle device according to claim 8, wherein the electronic unit of the seat unit re-sends the signal according to (iii) if not having revived an acknowledgment signal within a waiting time interval after having send out the previous signal according to (iii).

10. The vehicle device according to claim 9, wherein the electronic unit returns to its first state if not having received an acknowledge signal after having send a predetermined number of signals according to (iii).

11. The vehicle device according to claim 1, wherein the timing means generates a wake-up signal after a resting-time that starts when the electronic unit has transferred from its second state to its first state.

12. The seat unit adapted for being a part of a vehicle device according to claim 1 and comprising: a seat element; a sensor; an electronic unit comprising: (a) a timing means for generating time-spaced wake-up signals S(t); (b) a read-out means for reading out the sensor to retrieve values V(t) from the sensor; (c) a storage means; (d) a comparing means; (e) a seat-side wireless communication means adapted for wireless communication with the vehicle-side wireless communication means; and; a battery for supplying the electronic unit with electrical power, wherein; (i) the read-out means according to (b) reads out the value V(t) after having received a wake-up signal S(t) according to (a); (ii) the comparing means according to (d) compares the value V(t) according to (i) with a stored value V.sub.s stored in the storage means according to (c); (iii) the seat-side wireless communications means according to (e) sends out a signal representing the value V(t) if V(t) #V.sub.s and does not send out a sensor related signal if V(t)=V.sub.s; and (iv) the value V(t) is stored as the new stored value V.sub.s if V(t)?V.sub.s.

Description

[0028] The invention will now be described in detail by means of a preferred embodiment in view of the figures. The figures show:

[0029] FIG. 1 a vehicle device according to the invention in a top view, wherein a roof of the base vehicle of the vehicle device is not shown, and

[0030] wherein a seat unit of the vehicle device is remote from the base vehicle,

[0031] FIG. 2 what is shown in FIG. 1 with the seat unit being mounted to the mounting rails of the base vehicle,

[0032] FIG. 3 a schematic representation of the seat unit and the vehicle-side antenna, and

[0033] FIG. 4 a flow chart showing an operation modus of the seat unit.

[0034] FIG. 1 shows a first embodiment of a vehicle device according to the invention. In terms of this patent application, this vehicle device comprises a base vehicle 10 and a seat unit 30 which can be attached to the base vehicle and be removed from it. In FIG. 1, the seat unit 30 is removed from the base vehicle 10. The base vehicle 10 is here in form of a van or a minibus and is provided with seat mounting rails 18 to which the seat unit 30 can be mounted. Since the detection of the position of a mounted seat unit is not in focus of this invention, the mounting of the seat unit to the base vehicle does not necessarily have to occur via a rails system, it would also be possible that there is only one dedicated position for the seat unit within the base vehicle.

[0035] According to the definitions chosen in this patent application, the seat unit 30 comprises the seat element, an electronic unit and a battery. In the embodiment shown, the electronic unit 30 comprises a controller 41 and a seat-side antenna 44. The controller 41 is of course connected to the battery 46 and the seat-side antenna 44 is of course also directly or indirectly provided with electric energy form the battery 46.

[0036] The base vehicle 10 comprises a vehicle-side antenna 24, which is at least indirectly connected to the ECU of the base vehicle (not shown in the figures). Both, the seat-side antenna 44 and the vehicle-side antenna 24 are transmitting and receiving antennas, such that a bi-directional, wireless communication path is established by those two antennas; of course both of those antennas could be split into a receiving and a transmitting antenna. The term antenna is to be understood broadly and comprises all means for sending/receiving an electromagnetic signal, but preferably the antennas operate in a frequency range between 100 MHz and 2.5 GHz.

[0037] FIG. 2 shows what is shown in FIG. 1 but with the seat unit 30 being mounted to the seat mounting rails 18 of the base vehicle 10, such that the antennas 24 and 44 can establish a bi-directional communication path.

[0038] FIG. 3 shows the relevant elements of the seat unit 30 as well as the vehicle-side antenna 24. The seat unit 30 comprises (or course) a seating 32 (since here the seat of the seat unit 30 is a three-person-bench, three seatings 32 are provided, but for simplicity, only one is shown), an electronic unit, a battery 46, as well as two sensors, namely a seat occupancy sensor 34 and a buckle sensor 39, both being connected to the controller 41 (of course other types of sensors could be present). According to the definitions chosen in this application, the seat-side antenna 44 and the controller 41 are parts of the electronic unit 40.

[0039] The controller is usually an integrated circuit but can functionally be looked at as comprising a timing means, a read out means for reading out the sensors to retrieve values from the sensors, a storage means for storing values, and a comparing means for comparing measured and stored values.

[0040] In view of the flow chart of FIG. 4 it is now described how this system works. At an (arbitrary) starting point, the electronic unit 40 is in a first state, also called sleep-mode. As the word sleep-mode already says, in this first state the electronic unit has a minimized power consumption, such that it needs only very little energy from the battery, for example 10 ?W. The timing means of the controller 41 generates a wake-up-signal S(t) at the time t, for example at a fixed time after the electronic unit 40 has changed to its first state (sleep-mode). For example, the wake-up-signal S(t) could be generated five seconds after the last transition into the first state. Of course, other time intervals could be chosen. After this wake-up-signal S(t) has been generated, the electronic unit 40 awakes and changes into its second state (active-mode), in which its power consumption is higher than in the first state.

[0041] Now that the controller 41 (and thus the electronic unit 40) is in its second state, its read-out means reads out the actual value V.sup.39(t) from the buckle sensor 39 and the actual value V.sup.34(t) from the seat occupancy sensor 34. In a next step, the actual value of the buckle sensor V.sup.39(t) is compared to a stored value V.sup.39s of the buckle sensor and the actual value V.sup.34(t) of the seat occupancy sensor is compared to a value V.sup.34s of the seat occupancy sensor.

[0042] If both actual values V.sup.34(t) and V.sup.39(t) are equal to their respective stored values V.sup.34s and V.sup.39s, the electronic unit 40 only sends out an alive-signal SL(t) via its seat-side antenna 44 and then returns to its first state (sleep-mode). In this case the ECU of the base vehicle knows, that the seat unit is mounted inside the base vehicle (otherwise it would not receive an alive-signal) and that its state has not changed since the last signal. So, the base vehicle has all necessary information about the seat unit.

[0043] But, if one of the actual values V.sup.39(t)/V.sup.34(t) is not equal to its stored value V.sup.34s/V.sup.39s, this changed value is stored as the new stored value, such that the stored values V.sup.34s and V.sup.39s always correspond to the latest actual values. So, one could also say that the comparing means compares V.sup.34(t) with V.sup.34(t?1) and V.sup.39(t) with V.sup.39(t?1).

[0044] After at least one change has been found by the comparing means, the electronic unit 40 further sends out a value related signal So(t). This signal thus contains a real information, namely about the value of the respective sensor. In principal it would be possible, that the electronic unit 40 now returns to its first state, but in order to verify that this value related signal So(t) is received by the base vehicle, the base vehicle 10 generates an acknowledgement signal SAC after having received the value related signal So(t). The electronic unit 40 waits for this acknowledgement signal SAC and returns to the first state after having received it. If this acknowledgment signal is not received after a defined time interval, the value related signal So(t) is re-sent and the electronic unit 40 again waits for the acknowledgement signal. This sub-loop is repeated for a maximum number of tries and when the electronic unit 40 returns to its first state, even if no acknowledgement signal is received. This is necessary, because it could happen that something is placed onto the seat unit of a not mounted seat unit (for example while standing in a garage) and if the number of the transmission tries were not limited, the seat unit would stay in its second state (active mode) forever and would thus consume more energy than necessary.

[0045] It should be noted, that providing a bi-directional system as described above is preferred but that the basic concept could also be applied to a uni-directional system with the seat-side antenna being a transmitting antenna and the vehicle-side antenna being a receiving antenna.

LIST OF REFERENCE NUMBERS

[0046] 10 base vehicle [0047] 12 driver's seat [0048] 14 front passenger seat [0049] 16 windscreen [0050] 18 seat mounting rail [0051] 24 vehicle-side antenna [0052] 30 seat unit [0053] 32 seating [0054] 34 seat occupancy sensor [0055] 35 seatbelt [0056] 36 tongue [0057] 38 buckle [0058] 39 buckle sensor [0059] 40 electronic unit [0060] 41 controller [0061] 44 seat-side antenna [0062] 46 battery