Communication system and seat unit

A communication system includes a seat unit mounted on a seat of a vehicle and operating by an electrical power supplied from a battery, and a vehicle unit that wirelessly communicates with the seat unit, and transmits a start command. The seat unit receives the start command in a standby state in which a power consumption is lower than a normal state, and then the seat unit switches from the standby state to the normal state. After that, the seat unit transmits an information on an electronic device mounted on the seat, in the normal state. According to the communication system, the seat unit switches from the standby state to the normal state, only when the vehicle unit transmits the start command. Therefore, battery life can be extended.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2019-096840 filed on May 23, 2019, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a communication system and a seat unit. The communication system includes the seat unit that is mounted on a seat of a vehicle and that operates in response to power supply from a battery, and a vehicle unit that wirelessly communicates with the seat unit.

BACKGROUND ART

As a communication system described above, a signal receiving device described in JP2013-067322A has been proposed. The signal receiving device performs infrared communication between a slide seat and a vehicle, and uses a battery as a power source of a slide seat, so that routing of wire harness between the slide seat and the vehicle is avoided.

However, according to the signal receiving device described above, communication between the slide seat and the vehicle is being performed even when communication with the slide seat is not required. For this reason, there is a problem that battery exhaustion occurs quickly.

SUMMARY OF INVENTION

The present disclosure is to provide a communication system capable of extending battery life and a seat unit.

According to a first illustrative aspect of the present disclosure, a communication system includes a seat unit that is mounted on a seat of a vehicle and is configured to operate in response to an electrical power supplied from a battery, and a vehicle unit that wirelessly communicates with the seat unit. The vehicle unit transmits a start command. And, the seat unit receives the start command in a standby state, the standby state being a state in which a power consumption is lower than a normal state, the normal state being a state in which the power consumption is higher than the standby state. The seat unit switches from the standby state to the normal state, and transmits an information on an electronic device mounted on the seat, in the normal state.

According to a second illustrative aspect of the present disclosure, the seat unit switches to the standby state after transmitting the information on the electronic device.

According to a third illustrative aspect of the present disclosure, the seat unit determines whether the information on the electronic device changes in the standby state. The seat unit switches to the normal state and transmits the information on the electronic device, when the seat unit determines that the information on the electronic device changes.

According to a fourth illustrative aspect of the present disclosure, the seat unit determines whether the information on the electronic device changes in the normal state. The seat unit transmits the information on the electronic device when the seat unit determines that the information on the electronic device changes.

According to a fifth illustrative aspect of the present disclosure, the vehicle unit transmits the start command, depending on whether an ignition turns on from an off-state of the ignition or turns off from an on-state of the ignition.

According to a sixth illustrative aspect of the present disclosure, the seat unit and the vehicle unit wirelessly communicates with each other, such that an optical pulse signal is transmitted and received. The vehicle unit transmits a change command for which an output of the optical pulse signal is adjusted, when the vehicle unit determines that an amplitude or a rising of the optical pulse signal received from the seat unit varies includes a dispersion of the amplitude or the rising. And, the seat unit changes the output of the optical pulse signal and retransmits the changed optical pulse signal, when receiving the change command from the vehicle unit after transmitting the optical pulse signal.

According to a seventh illustrative aspect of the present disclosure, a seat unit is mounted on a seat of a vehicle, is configured to operate in response to an electrical power supplied from a battery, and wirelessly communicates with a vehicle unit. And, the seat unit receives a start command in a standby state, the standby state being a state in which a power consumption is lower than a normal state, the normal state being a state in which the power consumption is higher than the standby state. The seat unit switches from the standby state to the normal state, and transmits an information on an electronic device mounted on the seat, in the normal state.

According to the first, fifth and seventh illustrative aspects, only when the start command is transmitted by the vehicle unit, the seat unit switches from the standby state to the normal state and transmits the information on the electronic device mounted on the seat. Accordingly, battery life can be extended.

According to the second illustrative aspect, the seat unit switches to the standby state after transmitting the information on the electronic device. Accordingly, the battery life can be further extended.

According to the third and fourth illustrative aspects, the seat unit transmits the information on the electronic device only when the information on the electronic device changes. Accordingly, it is possible to transmit necessary information to the vehicle unit while extending the battery life.

According to the sixth illustrative aspect, when it is determined that the amplitude or the rising of the optical pulse signal from the seat unit varies, the vehicle unit causes the output of the optical pulse signal to be changed. Accordingly, it is possible to reduce the influence from disturbance light and from foreign matters adhered to a light emitting element, thereby preventing a decrease in communication performance.

According to the present disclosure, it is possible to provide a communication system capable of extending battery life and a seat unit.

The present disclosure is briefly described as above. Further, details of the present disclosure will be clarified by reading a mode for carrying out the present disclosure (hereinafter, referred to as “embodiments”) described below with reference to the accompanying drawings.

DESCRIPTION OF EMBODIMENTS

First Embodiment

As illustrated inFIG. 1, the communication system1according to the first embodiment includes a seat unit2provided on a slide seat (seat)4, and a vehicle unit3provided on a vehicle (vehicle body). The communication system1is a system capable of performing bidirectional optical wireless communication between the seat unit2and the vehicle unit3.

The slide seat4is mounted on the vehicle and mainly includes a seat cushion41and a seat back42. With an upper rail5attached to a lower surface of the seat cushion41, and with a rail6that is disposed below the seat cushion41and to which the upper rail5is slidably attached, the slide seat4is slidable along a front-rear direction D1of the vehicle.

The seat unit2operates depending on a battery21. In the present embodiment, the battery21is configured with a primary battery that cannot be charged, and is, for example, a battery that needs to be regularly replaced at the time of vehicle inspection.

The seat unit2includes the battery21, a seating switch SW1, a buckle switch SW2, a control unit22, a light emitting unit23, and a light receiving unit24. The seating switch SW1is one of electronic devices mounted on the slide seat4. The seating switch SW2is, for example, disposed in the seat cushion41, is pressed to be turned ON when an occupant sits on the slide seat4, and is turned OFF when the occupant gets out of the slide seat4. Seating of the occupant can be detected based on an ON and OFF state of the seating switch SW2.

The buckle switch SW2is one of the electronic devices mounted on the slide seat4. The buckle switch SW2is provided in a buckle of a seat belt, is turned ON when a tongue is inserted into the buckle of the seat belt, and is turned OFF when the tongue is pulled out. Seat belt wearing of the occupant can be detected based on an ON and OFF state of the buckle switch SW2.

In the present embodiment, as illustrated inFIG. 2, the seating switch SW1and the buckle switch SW2are connected in series, and a Lo level signal is input to an input terminal of the control unit22, which will be described below, only when both of the switches SW1and SW2are turned on. On the other hand, when either one of the switches SW1and SW2is OFF, a. Hi level signal is input to the input terminal of the control unit22, The Hi level signal is a signal generated based on a power supply voltage from the battery21.

In the present embodiment, the seating switch SW1and the buckle switch SW2are described as examples of the electronic devices mounted on the slide seat4, and the present disclosure is not limited thereto. For example, various sensors provided in the slide seat4may be the electronic devices.

The control unit22is configured with a microcomputer, and is constantly supplied with power from the battery21. The control unit22performs optical wireless communication, by controlling the light emitting unit23and the light receiving unit24to transmit and receive an optical pulse signal to and from the vehicle unit3, which will be described below. The light emitting unit23is configured with a light emitting diode, and transmits an optical pulse signal by flashing. The light receiving unit24is configured with a photodiode, and receives an optical pulse signal from the light emitting unit23of the vehicle unit3, which will be described below. As illustrated inFIG. 1, the light emitting unit23and the light receiving unit24are attached to the upper rail5.

In the present embodiment, the control unit22acquires ON and OFF information on the switches SW1and SW2based on signals from the seating switch SW1and the buckle switch SW2, controls the light emitting unit23, and outputs an optical pulse signal indicating the acquired ON and OFF information. The control unit22can switch between a standby state and a normal state. The standby state is a state in which power consumption can be kept low by lowering a processing speed (delaying a clock). The normal state is a state in which the processing speed can be raised (the clock is quickened) while the power consumption is increased.

Upon receiving a start signal (start command) from the vehicle unit3during the standby state, the control unit22switches to the normal state and transmits the ON and OFF information on the seating switch SW1and the buckle switch SW2.

The vehicle unit3is disposed, for example, on an instrument panel of the vehicle, and operates in response to power supply from a battery7. The battery7is configured with a secondary battery and is charged by an alternator. The vehicle unit3includes a control unit32, a light emitting unit33, and a light receiving unit34.

The control unit32is configured with a microcomputer. The control unit32performs optical wireless communication, by controlling the light emitting unit33and the light receiving unit34to transmit and receive an optical pulse signal to and from the seat unit2. The light emitting unit33is configured with a light emitting diode, and outputs an optical pulse signal by flashing. The light receiving unit34is configured with a photodiode, and receives an optical pulse signal from the light emitting unit23of the seat unit2. The light emitting unit33and the light receiving unit34are attached to the rail6, and are disposed to face the light emitting unit23and the light receiving unit24of the seat unit2in the front-rear direction D1.

When an ignition (IG) is turned ON from being OFF, the control unit32controls the light emitting unit33to output an optical pulse signal indicating a start signal. In the present embodiment, as illustrated inFIG. 3, the start signal is one pulse signal having a period longer than that of an optical pulse signal, other than the start signal, indicating transmission data (ON and OFF information or the like).

As illustrated inFIG. 2, the control unit32communicates with a meter ECU8, and the meter ECU8controls an indicator9in accordance with a command from the control unit32. The indicator9includes a seat belt wearing warning lamp (not illustrated), lighting of which is controlled by the meter ECU8, and an inspection lamp (not illustrated) of the seat unit2.

Next, operations of the communication system1having the configuration described above will be described with reference toFIGS. 4 and 5. First, when an IG switch is switched from off to on, the control unit32of the vehicle unit3(hereinafter, also abbreviated as “vehicle unit3”) performs processing illustrated inFIG. 4. First, the vehicle unit3transmits a start signal to the seat unit2(step S1). Thereafter, if the IG switch is ON (N in step S2), the vehicle unit3performs regular communication to transmit an ON and OFF information transmission command to the seat unit2(step S3). In step S3, the vehicle unit3adjusts time so as to perform regular communication at an interval of, for example, 1 second.

Next, the vehicle unit3determines whether there is a reply (ON and OFF information) in response to the transmission command (step S4), If there is no reply from the seat unit2(N in step S4), the vehicle unit3determines that there is a failure such as battery exhaustion of the seat unit2, commands the meter ECU8to turn on the inspection lamp (step S5), and returns to step S2. The meter ECU8controls the indicator9in accordance with the command from the vehicle unit3to turn on the inspection lamp.

Meanwhile, if there is a reply from the seat unit2(Y in step S4), the vehicle unit3performs determination of the replied ON and OFF information (step SC). If it is determined as a result that the information indicates both of the switches SW1and SW2are turned on (Y in step SC), the vehicle unit3determines that an occupant seated on the slide seat4is wearing a seat belt, commands the meter ECU8to turn off a warning lamp (step S7), and returns to step S2. The meter ECU8controls the indicator9in accordance with the command from the vehicle unit3to turn off the warning lamp.

If it is determined as a result that the information indicates that either one of the switches SW1and SW is off (N in step SC), the vehicle unit3determines that the occupant seated on the slide seat4is not wearing the seat belt, and then determines whether a vehicle speed is equal to or greater than a predetermined speed (for example, 20 km/h) (step S8). If the vehicle speed is less than 20 km/h (N in step S8), the vehicle unit3determines that there is no problem even if the seat belt is not worn and commands the meter ECU8to turn off the warning lamp (step S9), and returns to step S2. The meter ECU8controls the indicator9in accordance with the command from the vehicle unit3to turn off the warning lamp.

If the vehicle speed is equal to or greater than 20 km/h (Y in step S8), the vehicle unit3commands the meter ECU8to flash the warning lamp (step S10), and returns to step S2. The meter ECU8controls the indicator9in accordance with the command from the vehicle unit3to flash the warning lamp.

If the IG is switched from ON to OFF (Y in step S2), the vehicle unit3transmits a sleep signal (step S11), and thereafter ends the processing.

The control unit22of the seat unit2(hereinafter, also abbreviated as “seat unit2”) performs processing illustrated inFIG. 5in response to power supply from the battery21. First, the seat unit2switches to a standby state (step S20), and waits for reception of a start signal (step S21). Upon receiving a start signal (Y in step S21), the seat unit2is started and switched to a normal state (step S22).

Thereafter, upon receiving a transmission command from the vehicle unit3(Y in step S24) without receiving a sleep signal from the vehicle unit3step S23), the seat unit2acquires ON and OFF information on the switches SW1and SW2and transmits the ON and OFF information (step S25), and thereafter returns to step S23. On the other hand, while the transmission command from the vehicle unit3cannot be received (N in step S24), the seat unit2immediately returns to step S23. Upon receiving the sleep signal from the vehicle unit3(Y in step S23), the seat unit2returns to step S20, and is changed to the standby state to wait for reception of a start signal (step S21).

According to the communication system1and the seat unit2described above, only when the vehicle unit3has transmitted the start signal, the seat unit2switches from the standby state to the normal state and transmits ON and OFF information on the switches SW1and SW2mounted on the slide seat4. Accordingly, battery life can be extended.

Second Embodiment

Next, a second embodiment will be described. According to the first embodiment described above, the seat unit2switches from a normal state to a standby state only when a sleep signal is transmitted from a vehicle unit3side, and the present disclosure is not limited thereto. The seat unit2may transmit the ON and OFF information after entering the normal state, and thereafter spontaneously return to the standby state. In the first embodiment, the seat unit2transmits the ON and OFF information only when having received an ON and OFF information transmission command from the vehicle unit3. In the second embodiment, the seat unit2may acquire the ON and OFF information regularly during the standby state, and transmit an ON and OFF state to the vehicle unit3only when there is change in the ON and OFF information.

Specific operations of the second embodiment schematically described above will be described below with reference to flowcharts ofFIGS. 6 and 7. InFIGS. 6 and 7, steps same as those already described in the first embodiment described above with reference toFIGS. 4 and 5are denoted by the same reference numerals, and a detailed description thereof will be omitted.

Similarly to the first embodiment, when an IG switch is switched from OFF to ON, the vehicle unit3performs processing illustrated inFIG. 6and performs steps S1and S2. Thereafter, the vehicle unit3waits for reception of the ON and OFF information from the seat unit2(step S12). While the ON and OFF information cannot be received (N in step S12), the vehicle unit3returns to step S2. If the ON and OFF information can be received (V in step S12), the vehicle unit3performs steps S6to S10similarly to the first embodiment.

On the other hand, similarly to the first embodiment, the seat unit2performs processing illustrated inFIG. 7in response to power supply of the battery21, and performs steps S20to S22. Thereafter, the vehicle unit3acquires the ON and OFF information on the switches SW1and SW2, transmits the ON and OFF information (step S26), and thereafter spontaneously returns to the standby state (step S27). The vehicle unit3monitors the ON and OFF information in the standby state. If there is change in the ON and OFF information (Y in step S28), the vehicle unit3proceeds to step S22to switch to the normal state, and then to S26to transmit the ON and OFF information acquired in step S28.

On the other hand, if there is no change in the ON and OFF information (N in step S28), the seat unit2determines whether a sleep signal has been received from the vehicle unit3(step S29). If the sleep signal has not been received (step S29), the seat unit2returns to step S28again. On the other hand, when the sleep signal is received (step S29), the seat unit2returns to step S21and enters a standby state for a start signal.

According to the communication system1of the second embodiment described above, the seat unit2spontaneously switches to the standby state after transmitting the ON and OFF information. Accordingly, the battery life can be further extended.

According to the communication system1of the second embodiment described above, the seat unit2transmits the ON and OFF information only when the ON and OFF information has changed. Accordingly, it is possible to transmit necessary information to the vehicle unit3while extending the battery life.

Third Embodiment

Next, a third embodiment will be described. With respect to optical communication between the seat unit2and the vehicle unit3, communication performance may decrease due to influence of adherence of a large amount of grease applied to the rail6to the light emitting unit23, disturbance light or the like.

Therefore, in the third embodiment, when reception of an optical pulse signal indicating ON and OFF information from the seat unit2fails, the vehicle unit3transmits an output change command, which is for increasing output of the optical pulse signal, to the seat unit2. The seat unit2outputs an optical pulse signal whose output is increased in response to reception of the output change command, thereby preventing a decrease in communication performance.

Whether reception of an optical pulse signal has failed can be determined as follows. When the communication performance is not poor, as illustrated inFIG. 8A, optical pulse signals that have substantially the same amplitude and rising of waveform can be received. On the other hand, when the communication performance is poor, as illustrated inFIG. 8B, optical pulse signals that vary in the amplitude and rising of waveform are received. It is difficult to read accurate information from such optical pulse signals. Therefore, the vehicle unit3determines that the reception has failed when there is variation in amplitude and rising of the received optical pulse signals, and determines that the reception is successful when there is no variation.

Specific operations of the third embodiment schematically described above will be described below with reference to flowcharts ofFIGS. 9 and 10. InFIGS. 9 and 10, steps same as those already described in the first embodiment described above with reference toFIGS. 4 and 5are denoted by the same reference numerals, and a detailed description thereof will be omitted.

Similarly to the first embodiment, when an IG switch is switched from OFF to ON, the vehicle unit3performs processing illustrated inFIG. 9and performs steps S1to S4. If it is determined in step S4that there is a reply, the vehicle unit3determines whether reception of an optical pulse signal indicating ON and OFF information has failed (step S13) If the reception of the optical pulse signal has failed (Y in step S13), the vehicle unit3transmits an output change command (step S14), and returns to step S2. If the reception of the optical pulse signal has not failed (N in step S13), the vehicle unit3performs steps S6to S10similarly to the first embodiment.

On the other hand, similarly to the first embodiment, the seat unit2performs processing illustrated inFIG. 10in response to power supply of the battery21, and performs steps S20to S25. Thereafter, upon receiving the output change command from the vehicle unit3(Y in step S30), the seat unit2increases output and retransmits an optical pulse signal indicating the ON and OFF information (step S31). If the output change command from the vehicle unit3is not received step S30), the seat unit2returns to step S23.

According to the communication system1of the third embodiment described above, when it is determined that the amplitude or rising of the optical pulse signals from the seat unit2varies, the vehicle unit3causes the output of the optical pulse signal to be changed. Accordingly, it is possible to reduce the influence from disturbance light and from the grease (foreign matter) adhered to the light emitting unit23, thereby preventing a decrease in communication performance.

The present disclosure is not limited to the embodiment described above and may be appropriately modified, improved, or the like. In addition, the material, shape, size, number, arrangement position and the like of each component in the embodiment described above are optional and are not limited as long as the present disclosure can be achieved.

According to the embodiments described above, the seat unit2and the vehicle unit3perform optical wireless communication, and the present disclosure is not limited thereto. Wireless communication may be performed between the seat unit2and the vehicle unit3, and wireless communication using radio waves or the like may be performed therebetween.

Further, according to the second embodiment, the seat unit2returns to the standby state spontaneously after transmitting the ON and OFF information in the normal state, and returns to the normal state to transmit the ON and OFF information when it is determined that there is change in the ON and OFF information in the standby state, and the present disclosure is not limited thereto. The seat unit2may maintain the normal state from when the start signal from the vehicle unit3is received to when the sleep signal is received, and may transmit the ON and OFF information when it is determined that there is change in the ON and OFF state in the normal state.

Further, according to the embodiment described above, at a timing when the IG switch is turned ON from being OFF, the vehicle unit3performs the processing illustrated inFIG. 4, and transmits the start signal, and the present disclosure is not limited thereto. At a timing when the IG switch is turned on and the vehicle speed is equal to or greater than 20 km/h, the vehicle unit3may perform the processing illustrated inFIG. 4and transmit the start signal. In this case, if it is determined to be N in step S6, the vehicle unit3immediately proceeds to step S10without performing the operations of steps S8and S9inFIG. 4.

Further, according to the embodiments described above, a primary battery is used as the battery21, and the present disclosure is not limited thereto. A secondary battery may be used as the battery21, and be charged by an electromotive force generated by light reception of the light receiving unit24.

Illustrative aspects according to the present disclosure is described hereinafter. According to an illustrative aspect of the present disclosure, a communication system (1) includes a seat unit (2) that is mounted on a seat (4) of a vehicle and is configured to operate in response to an electrical power supplied from a battery (21), and a vehicle unit (3) that wirelessly communicates with the seat unit (2). The vehicle unit (3) transmits a start command. And, the seat unit (2) receives the start command in a standby state, the standby state being a state in which a power consumption is lower than a normal state, the normal state being a state in which the power consumption is higher than the standby state. The seat unit (2) switches from the standby state to the normal state, and transmits an information on an electronic device (SW1, SW2) mounted on the seat (4), in the normal state.

According to another illustrative aspect of the present disclosure, the seat unit (2) switches to the standby state after transmitting the information on the electronic device (SW1, SW2).

According to another illustrative aspect of the present disclosure, the seat unit (2) determines whether the information on the electronic device (SW1, SW2) changes in the standby state. The seat unit (2) switches to the normal state and transmits the information on the electronic device (SW1, SW2), when the seat unit determines that the information on the electronic device (SW1, SW2) changes.

According to another illustrative aspect of the present disclosure, the seat unit (2) determines whether the information on the electronic device (SW1, SW2) changes in the normal state. The seat unit (2) transmits the information on the electronic device (SW1, SW2) when the seat unit (2) determines that the information on the electronic device (SW1, SW2) changes.

According to another illustrative aspect of the present disclosure, the vehicle unit (3) transmits the start command, depending on whether an ignition turns on from an off-state of the ignition or turns off from an on-state of the ignition.

According to another illustrative aspect of the present disclosure, the seat unit (2) and the vehicle unit (3) wirelessly communicates with each other, such that an optical pulse signal is transmitted and received. The vehicle unit (3) transmits a change command for which an output of the optical pulse signal is adjusted, when the vehicle unit (3) determines that an amplitude or a rising of the optical pulse signal received from the seat unit (2) varies includes a dispersion of the amplitude or the rising. And, the seat (2) unit changes the output of the optical pulse signal and retransmits the changed optical pulse signal, when receiving the change command from the vehicle unit (3) after transmitting the optical pulse signal.

According to another illustrative aspect of the present disclosure, a seat unit (2) is mounted on a seat (4) of a vehicle, is configured to operate in response to an electrical power supplied from a battery (21), and wirelessly communicates with a vehicle unit (3). And, the seat unit (2) receives a start, command in a standby state, the standby state being a state in which a power consumption is lower than a normal state, the normal state being a state in which the power consumption is higher than the standby state. The seat unit (2) switches from the standby state to the normal state, and transmits an information on an electronic device (SW1, SW2) mounted on the seat (4), in the normal state.