Vehicle-mounted equipment

Abstract

To make two types of wireless communication, which are wireless communication between a base unit and a slave unit, and wireless communication between the base unit and a different unit, difficult to interfere with each other, while allowing the base unit to perform wireless communication with both slave unit and different unit.SOLUTION: An in-vehicle apparatus (91) includes a base unit (10) installed in a vehicle, a plurality of slave units (20) installed in the vehicle, and a different unit (10) installed in the vehicle and different from the slave units. The base unit performs wireless communication with the slave units using predetermined first wireless communication (C1), and also performs wireless communication with the different unit using predetermined second wireless communication (C2). The master unit has a first antenna (11) for performing the first wireless communication and a second antenna (12) for performing the second wireless communication. The plurality of slave units are installed inside a housing (50) that shields radio waves. The first antenna of the master unit is installed inside the housing, and the second antenna of the master unit is installed outside the housing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle device mounted on a vehicle. [Background technology]

[0002] Some in-vehicle devices have a master unit and multiple slave units that perform wireless communication with each other. Patent Document 1 below is a document that describes such in-vehicle devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6093448 Summary of the Invention [Problem to be solved by the invention]

[0004] In such in-vehicle devices, wireless communication is performed between the master unit and the slave units, eliminating wired communication between them. This simplifies the structure and improves the flexibility of arranging the master unit and each slave unit. However, among such in-vehicle devices, the master unit may communicate with a separate unit in addition to the slave units. In such cases, if the master unit is configured to communicate with the separate unit via wired communication, the significance of eliminating wired communication between the master unit and the slave units by wireless communication between them is diminished. On the other hand, if the master unit is configured to communicate with the separate unit via wireless communication in addition to the slave units, there is a risk of mutual interference between the two wireless communications, i.e., the wireless communication between the master unit and the slave unit and the wireless communication between the master unit and the separate unit.

[0005] The present invention has been made in consideration of the above circumstances, and its main object is to enable a parent unit in an in-vehicle device to perform wireless communication with both a child unit and another device, while making it difficult for the two wireless communications, the wireless communication between the parent unit and the child unit and the wireless communication between the parent unit and the other device, to interfere with each other. [Means for solving the problem]

[0006] The first means for solving the above problem is an in-vehicle device (91 to 93), The system includes a parent unit (10) mounted on a vehicle, a plurality of child units (20) mounted on the vehicle, and other units (10, 60, 70) mounted on the vehicle and separate from the child units, the parent device is configured to perform wireless communication with the child device through a predetermined first wireless communication (C1) and to perform wireless communication with the other device through a predetermined second wireless communication (C2); the master unit has a first antenna (11) for performing the first wireless communication and a second antenna (12) for performing the second wireless communication, The plurality of slave units are installed inside a housing (50) that shields radio waves, The first antenna of the base unit is installed inside the housing, and the second antenna of the base unit is installed outside the housing. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing an in-vehicle device according to a first embodiment; [Figure 2] FIG. 10 is a schematic diagram showing an in-vehicle device according to a second embodiment; [Figure 3] FIG. 10 is a schematic diagram showing an in-vehicle device according to a third embodiment; [Figure 4] FIG. 10 is a schematic diagram showing an in-vehicle device according to a modification of the first embodiment; [Figure 5] FIG. 10 is a schematic diagram showing an in-vehicle device according to a further modification of the first embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0008] Next, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment, and can be appropriately modified and implemented without departing from the spirit of the invention.

[0009] [First embodiment] First, an overview of the first embodiment will be described. As shown in Fig. 1, an in-vehicle device 91 is a battery monitoring system that monitors a battery pack 40 having a plurality of cell batteries 45. The in-vehicle device 91 has a plurality of parent devices 10 and a larger number of child devices 20. Although Fig. 1 shows two parent devices 10, the number may be three or more.

[0010] The slave devices 20 are installed in each cell battery group 44, which is obtained by dividing a plurality of cell batteries 45 into a plurality of groups. Each slave device 20 acquires battery information, which is information about the cell batteries 45, from the cell battery group 44 corresponding to itself. The master device 10 is installed in each slave device group B1, B2, which is obtained by dividing a plurality of slave devices 20 into a plurality of groups, and is responsible for each slave device 20 belonging to the slave device group B corresponding to itself.

[0011] The in-vehicle device 91 has a metal housing 50 for each of the slave groups B1 and B2. Each master unit 10 has a first antenna 11 for performing a predetermined first wireless communication C1 and a second antenna 12 for performing a predetermined second wireless communication C2. Inside each housing 50, each slave unit 20 belonging to the slave group B corresponding to that housing 50 is installed, and the first antenna 11 of the master unit 10 responsible for that slave unit 20 is installed, and the second antenna 12 of that master unit 10 is installed outside the housing 50.

[0012] Each master unit 10 is a monitoring ECU 10a that controls each slave unit 20 under its control, and acquires battery information from each slave unit 20 under its control through a first wireless communication C1. Each master unit 10 also wirelessly communicates with other master units 10 (referred to as "other units" in the present invention) through a second wireless communication C2.

[0013] The first wireless communication C1 and the second wireless communication C2 use different communication standards, which makes them less likely to interfere with each other than if they were the same. Specifically, the communication standard of the first wireless communication C1 uses radio waves in the 2.4 GHz band, and the communication standard of the second wireless communication C2 uses radio waves in the 5 GHz band.

[0014] Next, the details of this embodiment will be described in a manner that supplements the outline of this embodiment given above.

[0015] FIG. 1 is a schematic diagram showing an in-vehicle device 91 according to this embodiment. The components constituting the in-vehicle device 91 are mounted on a vehicle. Within each housing 50, a plurality of cell battery groups 44 are electrically connected in series. The plurality of cell batteries 45 constituting each cell battery group 44 are also electrically connected in series. Each cell battery 45 is a lithium battery or the like. The assembled batteries 40 within each housing 50 may be electrically connected in series or in parallel, for example.

[0016] Each slave unit 20 has a plurality of detection lines 25, and is capable of detecting the voltage of each cell battery 45 in the corresponding cell battery group 44 by using the plurality of detection lines 25. More specifically, the detection lines 25 are electrically connected to both ends of the cell battery group 44 and between each of the cell batteries 45 that make up the cell battery group 44.

[0017] Each slave device 20 has a slave device antenna 21 for performing first wireless communication C1 with the master device 10. The battery information that each slave device 20 transmits to the master device 10 via the first wireless communication C1 includes, for example, information about the voltage and temperature of each cell battery 45. Each slave device 20 is also configured to be able to execute an equalization process that equalizes the charge amounts of each cell battery 45 by discharging a cell battery 45 that has a higher charge amount than the other cell batteries 45 via a detection line 25.

[0018] The master unit 10 recognizes variations in the charge amounts of the cell batteries 45 based on the battery information transmitted by the first wireless communication C1 from each slave unit 20 it manages. The master unit 10 then controls each slave unit 20 it manages by transmitting commands to the slave units 20 by the first wireless communication C1. The commands include an equalization command for causing the slave units 20 to perform the above-mentioned equalization process.

[0019] In addition, each base unit 10 can exchange information with other base units 10 and synchronize control with other base units 10 by performing wireless communication with other base units 10 via the second wireless communication C2.

[0020] The housing 50 is made of metal and therefore blocks radio waves. However, because there are gaps and the like in the housing 50, some radio waves of the first wireless communication C1 leak to the outside of the housing 50, and some radio waves of the second wireless communication C2 leak to the inside of the housing 50. In this embodiment, the first wireless communication C1 and the second wireless communication C2 may be performed at the same time. Therefore, in this embodiment, as described above, the first wireless communication C1 and the second wireless communication C2 use different communication standards.

[0021] According to this embodiment, the following effects can be obtained. The master unit 10 performs wireless communication with the slave unit 20 via the first wireless communication C1, and performs wireless communication with other master units 10 via the second wireless communication C2. The first wireless communication C1 and the second wireless communication C2 have different communication modes, making them less likely to interfere with each other. Therefore, while the master unit 10 performs wireless communication C1, C2 with both the slave unit 20 and other master units 10, it is possible to make it less likely for the two wireless communications C1, C2, the first wireless communication C1 between the master unit 10 and the slave unit 20 and the second wireless communication C2 between the master units 10, to interfere with each other.

[0022] Specifically, the communication standard of the first wireless communication C1 uses radio waves in the 2.4 GHz band, while the communication standard of the second wireless communication C2 uses radio waves in the 5 GHz band. Therefore, the communication standard of the first wireless communication C1 and the communication standard of the second wireless communication C2 use different radio wave frequencies. Therefore, even if the first wireless communication C1 and the second wireless communication C2 are performed at the same time, the first wireless communication C1 and the second wireless communication C2 are unlikely to interfere with each other.

[0023] Furthermore, inside each metal housing 50, each handset 20 belonging to the handset group B corresponding to that housing 50 is installed, and the first antenna 11 of the base unit 10 responsible for that handset 20 is also installed. Therefore, the first wireless communication C1 for each handset group B can be shielded to some extent from the first wireless communication C1 for other handset groups B. Therefore, even if the first wireless communication C1 in each handset group B is of the same communication standard, the first wireless communication C1 in each handset group B1, B2 is unlikely to interfere with each other. Therefore, the distance between each handset group B1, B2 can be reduced.

[0024] The second antenna 12 of the base unit 10 is installed outside the metal housing 50. This makes it possible to more reliably avoid interference between the first wireless communication C1 and the second wireless communication C2. Furthermore, since the second antenna 12 of the base unit 10 is installed outside the metal housing 50 in this way, it is possible to avoid a situation in which the metal housing 50 makes it difficult for the radio waves of the second wireless communication C2 to reach the second antenna 12 or makes it difficult for the radio waves from the second antenna 12 to reach the other party.

[0025] Furthermore, a base unit 10 is installed for each of the slave units B1 and B2, and each base unit 10 performs first wireless communication C1 with each of the slave units 20 that it is responsible for. This allows for cases where it is difficult for one base unit 10 to perform wireless communication with all of the slave units 20, such as when there are a large number of slave units 20 or when the slave units 20 are located far from each other.

[0026] Furthermore, these monitoring ECUs 10a, which are parent units 10, communicate with each other via the second wireless communication C2. Therefore, even if the monitoring ECUs 10a are separated into multiple units, each monitoring ECU 10a can control each child unit 20 in unison.

[0027] [Second embodiment] Next, a second embodiment will be described. In the following embodiments, the same reference numerals will be used for components that are the same as or correspond to those in the previous embodiments. However, different reference numerals will be used for the in-vehicle devices themselves in each embodiment. This embodiment will be described based on the first embodiment, focusing on the differences from the first embodiment.

[0028] 2 is a schematic diagram showing an in-vehicle device 92 according to this embodiment. In this embodiment, one of the master devices 10 is a monitoring ECU 10a that controls all of the slave devices 20, and the master devices 10 other than the monitoring ECU 10a are repeaters 10b. Although FIG. 2 shows one master device 10 that is a repeater 10b, there may be two or more master devices 10.

[0029] The master unit 10, which is a repeater 10b, relays wireless communication between each slave unit 20 it manages and the master unit 10, which is a monitoring ECU 10a. Specifically, the master unit 10, which is a repeater 10b, transmits battery information acquired from each slave unit 20 it manages or information based thereon to the master unit 10, which is a monitoring ECU 10a, via the second wireless communication C2. When the master unit 10, which is a monitoring ECU 10a, sends a command to the slave unit 20 managed by the master unit 10, which is a repeater 10b, it transmits the command to the master unit 10, which is a repeater 10b, via the second wireless communication C2. Upon receiving the command, the master unit 10, which is a repeater 10b, transmits the command to the slave unit 20 via the first wireless communication C1.

[0030] According to this embodiment, the master device 10, which is the relay device 10b, relays wireless communication between each slave device 20 that it is responsible for and the master device 10, which is the monitoring ECU 10a. Therefore, one master device 10, which is the monitoring ECU 10a, can control all the slave devices 20.

[0031] [Third embodiment] Next, a third embodiment will be described. This embodiment will be based on the first embodiment, and the differences from the first embodiment will be mainly described.

[0032] FIG. 3 is a schematic diagram showing an in-vehicle device 93 of this embodiment. All of the master devices 10 are not monitoring ECUs but relay devices 10b. Although FIG. 2 shows two master devices 10, there may be three or more master devices 10. The in-vehicle device 93 also has a monitoring ECU 60 that controls each slave device 20, separate from the master device 10. In this embodiment, this "monitoring ECU 60" corresponds to the "separate device" of the present invention. The monitoring ECU 60 has an antenna 62 for performing the second wireless communication C2.

[0033] Each master unit 10 relays wireless communication between each slave unit 20 it manages and the monitoring ECU 60. Specifically, each master unit 10 transmits battery information or information based thereon, acquired from each slave unit 20 it manages via the first wireless communication C1, to the monitoring ECU 60 via the second wireless communication C2. When the monitoring ECU 60 needs to send a command to one of the slave units 20, it transmits the command to the master unit 10 that manages that slave unit 20 via the second wireless communication C2. Upon receiving the command, the master unit 10 transmits the command to that slave unit 20 via the first wireless communication C1.

[0034] According to this embodiment, each master device 10 relays wireless communication between each slave device 20 that it manages and the monitoring ECU 60. Therefore, all slave devices 20 can be controlled by a single monitoring ECU 60 that is separate from each master device 10. Furthermore, since all master devices 10 are relay devices 10b, the master devices 10 can be standardized to one standard.

[0035] [Other embodiments] The above-described embodiments can be modified as follows. For example, in the drawings of each embodiment, the number of slave devices 20 belonging to each slave device group B is three, but the number may be two, four, or more. Also, in each embodiment, the cell battery groups 44 are electrically connected in series within each housing 50, but they may also be connected in parallel.

[0036] 4, for example, in the first embodiment, the in-vehicle device 91 may further include a host ECU 70 that controls each master unit 10, which is a monitoring ECU 10a. The host ECU 70 may have an antenna 72 for performing the second wireless communication C2, and each master unit 10 may be configured to communicate with the other master units 10 as well as the host ECU 70 via the second wireless communication C2. In this case, the "host ECU 70" in addition to the "other master units 10" corresponds to the "separate device" as defined in the present invention.

[0037] 5, there may be only one master device 10, and the master device 10 may be configured to communicate only with the upper ECU 70 via the second wireless communication C2. In this case, only the "upper ECU 70" corresponds to the "separate device" of the present invention.

[0038] Furthermore, in each embodiment, for example, when the slave device groups B1 and B2 are sufficiently separated from each other, it is not necessary to provide a metal housing 50 for each slave device group B1 and B2. Furthermore, for example, the first wireless communication C1 may use radio waves of a frequency other than the 2.4 GHz band, and the second wireless communication C2 may use radio waves of a frequency other than the 5 GHz band.

[0039] Furthermore, for example, in each embodiment, the first wireless communication C1 and the second wireless communication C2 use different communication standards, but the frequencies used in the communication standard of the first wireless communication C1 and the frequencies used in the communication standard of the second wireless communication C2 may be the same or may partially overlap. Even in this case, it is possible to make the first wireless communication C1 and the second wireless communication C2 less likely to interfere with each other than when the communication standards themselves are the same.

[0040] Furthermore, in each embodiment, instead of or in addition to differentiating the communication standards of the first wireless communication C1 and the second wireless communication C2, the following may be done, for example: The first wireless communication C1 and the second wireless communication C2 are controlled using the same timer. The first wireless communication C1 is a communication mode that is executed when the second wireless communication C2 is not performed, and the second wireless communication C2 is a communication mode that is executed when the first wireless communication C1 is not performed.

[0041] Specifically, for example, a predetermined first period and a predetermined second period are set alternately, and in the first period, only the first wireless communication C1 is executed without the second wireless communication C2 being executed, and in the second period, only the second wireless communication C2 is executed without the first wireless communication C1 being executed. In this way, the first wireless communication C1 and the second wireless communication C2 are executed at different timings, so that even if the first wireless communication C1 and the second wireless communication C2 are of the same communication standard, the first wireless communication C1 and the second wireless communication C2 are prevented from interfering with each other.

[0042] Also, for example, in each embodiment, the on-vehicle devices 91 to 93 are battery monitoring systems, but may be other electrical devices. Specifically, for example, the on-vehicle devices 91 to 93 may be a tire pressure monitoring system (TPMS). In this case, a slave unit is installed for each tire and acquires tire pressure information, which is information related to the tire pressure, from the tire corresponding to the slave unit. Then, master units are installed, for example, at the front and rear of the vehicle. The front master unit is responsible for each of the two slave units installed on the left and right tires on the front side, and acquires tire pressure information from each of the slave units via the first wireless communication. The rear master unit is responsible for each of the two slave units installed on the left and right tires on the rear side, and acquires tire pressure information from each of the slave units via the first wireless communication. Then, the front and rear master units exchange information and the like via the second wireless communication. [Explanation of symbols]

[0043] 10...parent device, 20...child device, 60...monitoring ECU, 70...host ECU, 91-93...vehicle devices, C1...first wireless communication, C2...second wireless communication.

Claims

1. The system includes a parent unit (10) mounted on a vehicle, a plurality of child units (20) mounted on the vehicle, and other units (10, 60, 70) mounted on the vehicle and separate from the child units, the parent device is configured to perform wireless communication with the child device through a predetermined first wireless communication (C1) and to perform wireless communication with the other device through a predetermined second wireless communication (C2); The master unit has a first antenna (11) for performing the first wireless communication and a second antenna (12) for performing the second wireless communication, The plurality of slave units are installed inside a housing (50) that shields radio waves, the first antenna of the base unit is installed inside the housing, and the second antenna of the base unit is installed outside the housing; The on-board device is a battery monitoring system that monitors a plurality of cell batteries (45), The slave device acquires battery information, which is information about the cell battery; the master unit is installed for each of the slave unit groups (B1, B2) into which the plurality of slave units are divided, and each master unit is responsible for each of the slave units belonging to the corresponding slave unit group, and acquires the battery information from each of the slave units that it is responsible for through the first wireless communication; One of the parent devices is a monitoring ECU (10a) that controls each of the child devices, The master device other than the monitoring ECU is a relay device (10b) for relaying wireless communication between each slave device under its charge and the master device that is the monitoring ECU, The other device for the parent device that is the monitoring ECU is the parent device that is the relay device, and the other device for the parent device that is the relay device is the parent device that is the monitoring ECU, The parent device, which is the repeater, transmits the battery information or information based thereon acquired by the first wireless communication to the parent device, which is the monitoring ECU, via the second wireless communication.

2. The system includes a parent unit (10) mounted on a vehicle, a plurality of child units (20) mounted on the vehicle, and other units (10, 60, 70) mounted on the vehicle and separate from the child units, the parent device is configured to perform wireless communication with the child device through a predetermined first wireless communication (C1) and to perform wireless communication with the other device through a predetermined second wireless communication (C2); The master unit has a first antenna (11) for performing the first wireless communication and a second antenna (12) for performing the second wireless communication, The plurality of slave units are installed inside a housing (50) that shields radio waves, the first antenna of the base unit is installed inside the housing, and the second antenna of the base unit is installed outside the housing; The on-board device is a battery monitoring system that monitors a plurality of cell batteries (45), the slave device acquires battery information, which is information about the cell battery; The in-vehicle device (91 to 93) has only one master device that communicates with the other device.

3. The in-vehicle device according to claim 1 or 2, wherein the communication mode of the first wireless communication and the communication mode of the second wireless communication have different communication standards.

4. The in-vehicle device according to claim 3 , wherein the first wireless communication standard and the second wireless communication standard use different radio wave frequencies.

5. The in-vehicle device according to claim 4 , wherein the communication standard for the first wireless communication uses radio waves in a 2.4 GHz band, and the communication standard for the second wireless communication uses radio waves in a 5 GHz band.

6. The in-vehicle device according to claim 3 , wherein the first wireless communication standard and the second wireless communication standard use the same frequency of radio waves.

7. 3. The in-vehicle device according to claim 1, wherein the first wireless communication and the second wireless communication are controlled using a same timer, the first wireless communication is a communication mode that is executed at a timing when the second wireless communication is not performed, and the second wireless communication is a communication mode that is executed at a timing when the first wireless communication is not performed.

8. 8. The in-vehicle device according to claim 7, wherein a predetermined first period and a predetermined second period are set, during which only the first wireless communication is performed without the second wireless communication being performed, and during which only the second wireless communication is performed without the first wireless communication being performed.

9. The in-vehicle device according to claim 7 or 8, wherein the communication mode of the first wireless communication and the communication mode of the second wireless communication have the same communication standard.

10. The in-vehicle device according to claim 1 , wherein each of the master units and each of the slave units corresponding to the master unit are housed together in each of the housings.

11. Each of the parent devices is a monitoring ECU (10a) that controls each of the child devices that it is responsible for, The in-vehicle device (91) according to claim 1 or 10, wherein the separate device for each of the master devices is a master device other than the master device itself.

12. The separate device is a monitoring ECU (60) that is provided separately from each of the parent devices and controls each of the child devices, Each of the master units is a relay unit (10b) for relaying wireless communication between each of the slave units under its charge and the monitoring ECU, 11. The in-vehicle device (93) according to claim 1, wherein each of the master units transmits the battery information acquired through the first wireless communication or information based thereon to the monitoring ECU through the second wireless communication.

13. The vehicle-mounted equipment described in claim 11 or 12, wherein each of the sub-units is configured to be capable of executing an equalization process to equalize the charge amounts of each of the cell batteries by discharging the cell battery that has a higher charge amount than the other cell batteries.

14. The vehicle equipment described in claim 13, wherein the monitoring ECU recognizes variations in the charge levels of each of the cell batteries based on battery information transmitted from each of the sub-devices under its responsibility, and transmits an equalization command to each of the sub-devices under its responsibility to cause the equalization process to be performed.

15. The in-vehicle device according to claim 1 , wherein the plurality of slave units are all installed inside one of the housings.

16. The monitoring ECU is installed outside the housing, The in-vehicle device according to claim 12, wherein each of the slave units is installed inside the housing.

17. An on-board device according to any one of claims 1 to 16, wherein the housing is mounted on a vehicle and is not a building.

18. An automotive device described in any one of claims 1 to 17, wherein the housing is a metal housing mounted on a vehicle and does not have window glass used in buildings.

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