In-vehicle communication system

Abstract

To provide an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.SOLUTION: An in-vehicle communication system 10 includes: a plurality of ECUs 100 provided in a vehicle and each having a frequency band assigned thereto; a control unit 300 configured to transmit and receive communication data to and from the ECUs 100; and a relay unit 200. The relay unit 200 is connected to the control unit 300 through a first communication path 410 capable of frequency-multiplexing and transmitting the communication data corresponding to the different frequency bands. Moreover, the relay unit 200 is connected to the plurality of the ECUs 100 through a plurality of second communication paths 420 capable of transmitting the communication data in the frequency bands respectively assigned to the plurality of ECUs 100. Further, the relay unit 200 includes a plurality of filtering units 240 to pass through the communication data in the frequency bands respectively corresponding to the second communication path 420.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an in-vehicle communication system.

Background Art

[0002] Conventionally, an in-vehicle network system has been proposed in which a plurality of ECUs (Electronic Control Units) mounted on a vehicle are connected to a network and cooperate with each other through communication to realize functional cooperation. Patent Document 1 discloses a communication system connected to a communication network mounted on a vehicle and performing communication via the network. The communication system disclosed in Patent Document 1 increases the communication capacity of communication data based on the same protocol by modulating the frequency band of the input communication data to the frequency band of other communication data by a gateway.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the increase in the amount of information handled in a vehicle, communication in an in-vehicle network is required to be faster and have a larger capacity. However, in the communication system disclosed in Patent Document 1, it is necessary to dynamically convert the transmitted communication data to the frequency band of the destination and perform a process of switching the destination (switching process). That is, in an in-vehicle network where faster communication and larger capacity are required, a high-speed switching process is necessary, and power consumption increases in this switching process.

[0005] The present invention has been made in view of the problems of such conventional technologies. The object of the present invention is to provide an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.

Means for Solving the Problems

[0006] The in-vehicle communication system according to an aspect of the present invention is provided in a vehicle, and includes a plurality of ECUs to which different frequency bands are respectively assigned, a control unit that transmits and receives communication data between the ECUs, and a first communication path capable of frequency-division multiplexing and transmitting communication data corresponding to different frequency bands and connected to the control unit, and a relay unit connected to the plurality of ECUs by a plurality of second communication paths capable of transmitting communication data in the frequency bands respectively assigned to the plurality of ECUs. The relay unit has a plurality of filter units that transmit communication data in the frequency bands corresponding to the second communication paths.

Effects of the Invention

[0007] According to the present invention, it is possible to provide an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 7

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the in-vehicle communication system 10 according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios. Also, in the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0010] (Overview of the In-vehicle Communication System 10) FIG. 1 is a diagram showing an overview of the in-vehicle communication system 10. The in-vehicle communication system 10 is a communication system provided inside a vehicle such as an automobile, and includes a plurality of ECUs 100 (Electronic Control Units), a relay unit 200, and a control unit 300.

[0011] In a plurality of predetermined areas provided inside a vehicle such as an automobile, many sensors and devices such as actuators that convert electrical signals into motion are mounted. Also, the vehicle is equipped with various types of ECUs 100 corresponding to the devices and cameras in each of the above areas. The ECU 100 provided in each of these areas performs predetermined control based on the data acquired from these sensors and devices.

[0012] For the cooperative control between these ECUs 100, networking within the vehicle is progressing. The in-vehicle communication system 10 in the present embodiment includes a relay unit 200 and a control unit 300, and is a system that controls the exchange of communication data of each ECU 100.

[0013] As shown in FIG. 1, the relay unit 200 of the in-vehicle communication system 10 and the control unit 300 are connected via a wired network. In the present embodiment, the wired network to which the relay unit 200 and the control unit 300 are connected corresponds to the first communication path 410.

[0014] Also, the ECU 100 in each area and the relay unit 200 are connected via a wired network. In the present embodiment, the wired network to which the ECU 100 in each area and the relay unit 200 are connected corresponds to the second communication path 420. In the example shown in FIG. 1, the relay unit 200 is connected to each area of area AR1 to area AR4 by the second communication paths 420a to 420d. Hereinafter, when it is not necessary to distinguish each of the second communication paths for explanation, it is simply referred to as "the second communication path 420".

[0015] That is, in the in-vehicle communication system 10, the control unit 300 transmits and receives (sends and receives) communication data via the relay unit 200 to and from the ECU 100 that controls each area.

[0016] In the example shown in FIG. 1, an example corresponding to four areas from area AR1 to area AR4 for a predetermined location of the vehicle is shown. Note that the number of these areas does not limit the configuration of the present embodiment, and the in-vehicle communication system 10 may be configured to correspond to a number of areas less than 4 or a number of areas more than 4.

[0017] Also, in the example shown in FIG. 1, in each of the areas from area AR1 to area AR4, ECUs 100a to 100d are provided as ECUs 100 for controlling the area. Hereinafter, when it is not necessary to distinguish each of the ECUs for explanation, it is simply referred to as "ECU 100". Also, different frequency bands are assigned to each of the ECUs 100 in advance. The details of the frequency bands assigned to the ECUs 100 will be described later.

[0018] Also, the ECU 100 is generally composed of a microcomputer and its peripheral devices (such as a communication module). Also, a plurality of ECUs 100 corresponding to applications such as engine control, brake control, and safety control are installed in one vehicle. These functions are realized by the software incorporated in the ECU 100. Also, as described above, each ECU 100 is linked via a wired network.

[0019] The relay unit 200 is connected to each ECU 100 in each area and relays the communication data transmitted between the control unit 300 and the ECU 100. Also, the relay unit 200 may relay the communication data transmitted between the ECUs 100 without passing through the control unit 300.

[0020] The control unit 300 is a centralized control unit in the in-vehicle communication system 10 and transmits and receives communication data to and from each ECU 100 in each area.

[0021] (First Embodiment) FIG. 2 is a diagram showing the configuration of the in-vehicle communication system 10 in the first embodiment. In the first embodiment, the first communication path 410 and the second communication path 420 are constituted by optical fibers. Thus, in the first embodiment, by configuring the first communication path 410 and the second communication path 420 with optical fibers, it becomes possible to realize a network configuration suitable for high-speed large-capacity communication. Further, by configuring the first communication path 410 and the second communication path 420 with optical fibers, it becomes possible to realize a network configuration in which the influence of external noise is suppressed more than when the communication path is constituted by metal.

[0022] The control unit 300 includes a centralized control controller 101 and an E / O conversion unit 510 (electrical / optical conversion unit). The E / O conversion unit 510 of the control unit 300 has a function of converting an electrical signal transmitted from the centralized control controller 101 into an optical signal and transmitting it to the first communication path 410. Further, the E / O conversion unit 510 of the control unit 300 converts the optical signal received via the first communication path 410 into an electrical signal and sends it to the centralized control controller 101.

[0023] Similar to the ECU 100, the centralized control controller 101 is generally composed of a microcomputer and its peripheral devices (such as a communication module). The centralized control controller 101 controls the transmission of communication data to be exchanged with each ECU 100. Further, the functions provided by the centralized control controller 101 are realized, for example, by software incorporated in the centralized control controller 101.

[0024] The relay unit 200 includes an O / E conversion unit 520 (optical / electrical conversion unit), an E / O conversion unit 510, a distributor 230, and a plurality of filter units 240.

[0025] The O / E conversion unit 520 and the E / O conversion unit 510 of the relay unit 200 perform optical / electrical conversion and electrical / optical conversion between the first communication path 410 and the second communication path 420 through which optical signals are transmitted, and process communication data.

[0026] In addition, the control unit 300 generates component carriers (CCs) corresponding to the number of areas to be transmitted by determining the number of component carriers to be transmitted to one area, as well as the frequency and bandwidth. The component carriers achieve increased capacity by combining multiple frequency blocks.

[0027] The distributor 230 and the plurality of filter units 240 of the relay unit 200 distribute the communication data transmitted from the control unit 300 at a predetermined frequency and relay and transmit it to the destination ECU 100. Also, the distributor 230 and the plurality of filter units 240 of the relay unit 200 relay and transmit the communication data corresponding to the predetermined frequency transmitted from the ECU 100 to the control unit 300.

[0028] The filter unit 240 is a frequency filter that transmits a band of a predetermined frequency and is composed of, for example, a surface acoustic wave (SAW) filter. Note that the filter applied to the filter unit 240 is not limited to the type or filtering method as long as it can transmit communication data of a frequency in the required band. For example, the filter unit 240 may apply a low-pass filter (LPF) or a high-pass filter (HPF). Also, the filter unit 240 may apply filters such as a band-pass filter (BPF), a band-stop filter (BSF), or a band-rejection filter (BRF). In the example shown in FIG. 2, the filter unit 240 shows an example using a BPF. Also, the distributor 230 and the filter unit 240 may apply a "demultiplexer" that combines the functions of the distributor 230 and the filter unit 240 into one.

[0029] Also, the filter unit 240 is a filter that allows only the frequency components of the component carriers to pass through. That is, the filter unit 240 is a filter that can transmit communication data in the frequency band corresponding to the second communication path 420. As a result, a high-speed response on the time axis becomes unnecessary.

[0030] Further, when the carrier frequency and bandwidth assigned to each area are predetermined, the filter unit 240 can set a path with substantially negligible delay by using a passive filter composed of passive elements. The passive filter is a filter circuit composed of passive elements (passive devices) such as resistors, coils (inductors), and capacitors. Since the number of components is small, the circuit configuration is simple. Also, since the passive filter does not require an external power source (external power), it is possible to reduce the power consumption in the in-vehicle communication system 10.

[0031] FIG. 3A is a diagram for explaining the frequency distribution in the relay unit 200. As shown in FIG. 3A, communication data in which frequencies from frequency A to frequency D are frequency multiplexed is transmitted and received on the first communication path 410 between the control unit 300 and the relay unit 200. That is, the first communication path 410 is a path capable of multiplexing and transmitting communication data corresponding to different frequency bands. For example, the first communication path 410 may be configured to multiplex four frequency bands with a bandwidth of 2.5 GHz and enable communication data transmission with a bandwidth of 10 GHz.

[0032] Also, in the example shown in FIG. 3A, communication data of frequency A is transmitted and received on the second communication path 420a between the relay unit 200 and the ECU 100a in the area AR1. Similarly, communication data of frequency D is transmitted and received on the second communication path 420d between the relay unit 200 and the ECU 100d in the area AR4. Note that communication data of frequency B and frequency C are transmitted and received on the second communication path 420b between the relay unit 200 and the ECU 100b in the area AR2 and on the second communication path 420c between the relay unit 200 and the ECU 100c in the area AR3 (not shown). That is, the plurality of second communication paths 420 are a plurality of paths capable of transmitting communication data in the frequency bands respectively assigned to the plurality of ECUs 100.

[0033] Also, in the example shown in FIG. 3A, it is assumed that in area AR1, in addition to ECU100a serving as the area master, terminals 102a to 102d for controlling cameras and devices are provided. For example, the data of frequency A processed in area AR1 corresponds to four component carriers CC1 to CC4.

[0034] For example, in the example shown in FIG. 3A, the terminal 102b corresponding to the camera corresponds to the component carrier CC2 among the communication data of frequency A. Also, the terminal 102c corresponding to the device corresponds to the component carrier CC3 among the communication data of frequency A.

[0035] The data of each of these component carriers can be transmitted and received as communication data within the area. For example, when transmitting the communication data of CC3 from the terminal 102c of the device to the terminal 102b of the camera, the communication data is frequency-converted in the ECU100a which is the area master and then transmitted to the terminal 102b of the camera.

[0036] FIG. 3B is a diagram showing the flow of communication data transmitted and received in the first embodiment. For example, in FIG. 3B, the frequency band f1 with a bandwidth of B1 is applied to the communication between the control unit 300 and area AR1. Similarly, in FIG. 3B, the frequency band f4 with a bandwidth of B4 is applied to the communication between the control unit 300 and area AR4.

[0037] As described above, the in-vehicle communication system 10 according to the first embodiment is provided in a vehicle and includes a plurality of ECUs 100 to which different frequency bands are assigned, a control unit 300 that transmits and receives communication data to and from the ECUs 100, and a relay unit 200. The relay unit 200 is connected to the control unit 300 via a first communication path 410 capable of frequency-division multiplexing and transmitting communication data corresponding to different frequency bands. The relay unit 200 is also connected to the plurality of ECUs 100 via a plurality of second communication paths 420 capable of transmitting communication data in the frequency bands respectively assigned to the plurality of ECUs 100. Further, the relay unit 200 has a plurality of filter units 240 that transmit communication data in the frequency bands corresponding to the second communication paths 420.

[0038] Thereby, the in-vehicle communication system 10 can realize an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.

[0039] Also, the filter unit 240 of the in-vehicle communication system 10 may be a passive filter composed of passive elements. Thereby, the in-vehicle communication system 10 is composed of passive elements and has a small number of components, so the circuit configuration is simple. Further, since the passive filter does not require an external power source (external power), the in-vehicle communication system 10 can realize a network configuration with low power consumption.

[0040] Furthermore, the first communication path 410 and the second communication path 420 of the in-vehicle communication system 10 may be composed of optical fibers. By configuring the first communication path 410 and the second communication path 420 with optical fibers, the in-vehicle communication system 10 can realize a network configuration suitable for high-speed large-capacity communication. Also, by configuring the first communication path 410 and the second communication path 420 with optical fibers, the in-vehicle communication system 10 can realize a network configuration that suppresses the influence of external noise more than when the communication path is composed of metal.

[0041] That is, in the in-vehicle communication system 10, an ECU 100 is assigned to each area (so-called zoned ECU). Further, the in-vehicle communication system 10 includes a first communication path 410 that controls communication data aggregated from the ECU 100s in each area and aggregated communication data sent from the control unit 300 to the ECU 100s in each area. That is, the first communication path 410 is an in-vehicle network in which the distribution destination of communication data from the aggregated communication data to the ECU 100 (zone ECU) in each area is fixedly assigned for each frequency.

[0042] Also, when distributing communication data from the control unit 300 to the ECU (zone ECU) in each area, for example, when the relay unit 200 performs a switching operation with a switch, high-speed switching is required for time division multiplexing. On the other hand, the in-vehicle communication system 10 according to the present embodiment distributes communication data to each area fixed (assigned) by frequency, eliminating the need for a path switching switch. That is, the in-vehicle communication system 10 according to the present embodiment is an in-vehicle communication system capable of reducing the communication data speed with respect to TDM (Time Division Multiplexing) and reducing power consumption.

[0043] (Second Embodiment) As described above, one specific embodiment has been described, but the above-described embodiments are examples and do not limit the embodiments. For example, in the above-described embodiment, the form in which communication data is exchanged between the control unit 300 and each ECU 100 via the relay unit 200 is exemplified. Here, a configuration different from that of the first embodiment will be described for the in-vehicle communication system 10 according to the second embodiment in which communication data can be exchanged between the ECU 100s in the in-vehicle communication system 10.

[0044] FIG. 4 is a diagram for explaining the exchange of communication data in the in-vehicle communication system 10 according to the second embodiment. The in-vehicle communication system 10 according to the second embodiment is different from the in-vehicle communication system 10 according to the first embodiment in that transmission resource information is used as a control signal.

[0045] In the second embodiment, for each transmission source area, transmission resource information is transmitted to the control unit 300 every time a transmission is made. The control unit 300 that has received this transmission resource information controls the relay unit 200 so as not to exceed the bandwidth allowable in one area.

[0046] In the example shown in FIG. 4, from area AR4, transmission resource information with a bandwidth of B 4c and a signal with a bandwidth of B 14 indicating communication data from area AR4 to area AR1 are transmitted to the relay unit 200. The transmission resource information transmitted to the relay unit 200 is transmitted to the control unit 300. Based on the received transmission resource information, the control unit 300 controls the relay unit 200 so that communication data with a bandwidth of B 14 transmitted from area AR4 can be transmitted to area AR1.

[0047] Specifically, the control unit 300 sets the filter value of the filter unit 240 of the relay unit 200 so that communication data in the frequency band of the ECU100d of area AR4 can pass through the second communication path 420a to area AR1. By setting the filter value of the filter unit 240 by this control unit 300, the second communication path 420a connecting the relay unit 200 and area AR1 can transmit communication data in the frequency bands of the ECU100a of area AR1 and the ECU100d of area AR4. In the example shown in FIG. 4, an example is shown in which communication data with a bandwidth indicated by B1 transmitted from the control unit 300 and communication data with a bandwidth of B 14 transmitted from area AR4 are transmitted to the ECU100a of area AR1 via the second communication path 420a.

[0048] That is, when the control unit 300 receives transmission resource information including information about another ECU 100 that is the transmission destination of communication data from the ECU 100, the control unit 300 sets the value of the filter unit 240 so that the communication data transmitted from the ECU 100 can be transmitted to the other ECU 100. Thereby, in the in-vehicle communication system 10 according to the second embodiment, it is possible to freely set the communication bandwidth between areas.

[0049] In a conventional communication system, once communication data is sent to a higher-level switch or the like, it is then sent to another transceiver (area) in a retransmission manner. Therefore, not only does the communication time increase, but also address conversion (routing) performed by the higher-level switch and power consumption associated with retransmission occur. However, in the in-vehicle communication system 10 according to the second embodiment, in the transmission and reception of communication data between the ECUs 100, it is not necessary to pass through the control unit 300 or a higher-level switch or the like, and low-latency and low-power consumption communication can be realized between each area.

[0050] As described above, the control unit 300 of the in-vehicle communication system 10 according to the second embodiment may receive transmission resource information including information about another ECU 100 that is the transmission destination of communication data from the ECU 100. Further, when the control unit 300 of the in-vehicle communication system 10 receives the transmission resource information, the control unit 300 may set the filter value of the filter unit 240 so that the communication data transmitted from the ECU 100 can be transmitted to the other ECU 100.

[0051] Thereby, in the in-vehicle communication system 10 according to the second embodiment, in the transmission and reception of communication data between the ECUs 100, it is not necessary to pass through the control unit 300, and low-latency and low-power consumption communication can be realized between each area.

[0052] (Third Embodiment) Next, a third embodiment will be described. In the following description, when the same reference numerals as those in the first and / or second embodiments are used, the same configurations as those in the first and / or second embodiments are indicated, and the preceding descriptions are referred to unless otherwise specified. Here, a vehicle-mounted communication system 10 according to a third embodiment in which a predetermined area enables the use of the frequency bands of other areas will be described with respect to configurations different from those in the first and / or second embodiments.

[0053] FIG. 5 is a diagram for explaining the operation of the vehicle-mounted communication system 10 in the third embodiment. In the example shown in FIG. 5, the relationship between the frequencies assigned to each of the areas AR1 to AR4 is set as f1 < f2 < f3 < f4. In this case, since f4 has a device capable of responding to the frequencies from f1 to f3, transmission of communication data corresponding to f1 to f3 is possible. Specifically, in the filter unit 240 of the relay unit 200, the filter is set in advance so that communication data can be transmitted in a predetermined frequency band. That is, the filter unit 240 according to the third embodiment is capable of transmitting communication data not only in the frequency band of the corresponding second communication path 420 but also in a frequency band having a frequency value smaller than the frequency band of the corresponding second communication path. The filter value is set in advance.

[0054] As shown in FIG. 5, when the communication partners in the area corresponding to the rear areas of the vehicles corresponding to areas AR3 and AR4 are only areas AR1 and AR2, communication is possible as long as the transceivers in each area have the characteristic of responding to the assigned frequencies. For example, in the example shown in FIG. 5, in addition to the frequency band f3 of area AR3, communication data can be transmitted in the frequency band f1 of area AR1. In this case, for the second communication path 420c between area AR3 and the relay unit 200, the filter value of the filter unit 240 is set in advance so that communication data in the frequency bands f1 and f3 can be transmitted.

[0055] Similarly, in the example shown in FIG. 5, in addition to the frequency band f4 of area AR4, communication data can be transmitted in the frequency band f1 of area AR1 in area AR4. In this case, the filter values of the filter unit 240 are set in advance so that communication data in the frequency bands f1 and f4 can pass through the second communication path 420d between area AR4 and the relay unit 200.

[0056] That is, when the frequency band of ECU100 is larger than the frequency bands assigned to other ECU100s, ECU100 can directly transmit and receive communication data with other ECU100s having a smaller frequency band via the relay unit 200. That is, the filter unit 240 is set in advance so that communication data can pass through not only the frequency band of the corresponding second communication path 420 but also a frequency band having a frequency value smaller than the frequency band of the corresponding second communication path. Thereby, in a network configuration where all areas do not need to communicate with each other, by determining the frequency band for a predetermined area corresponding to the communication between necessary areas, it is possible to transmit communication data of a plurality of frequency bands with a simple configuration.

[0057] As described above, the filter values of the filter unit 240 of the in-vehicle communication system 10 according to the third embodiment may be set in advance so that communication data of a plurality of frequency bands can pass through. Specifically, the filter unit 240 may be set in advance so that communication data can pass through not only the frequency band of the corresponding second communication path 420 but also a frequency band having a frequency value smaller than the frequency band of the corresponding second communication path.

[0058] Thereby, in the in-vehicle communication system 10 according to the third embodiment, in a network configuration where all areas do not need to communicate with each other, the frequency band for a predetermined area can be determined corresponding to the communication between necessary areas. That is, the in-vehicle communication system 10 can transmit communication data of a plurality of frequency bands with a simple configuration, and can reduce device costs and power consumption.

[0059] (Other embodiments) Although the embodiments have been described in detail with reference to the drawings, the present embodiments are not limited by the contents described in the above embodiments. Further, the constituent elements described above include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described above can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the embodiments.

[0060] In the above-described second and third embodiments, in addition to the frequency bands assigned to the respective areas, a configuration is shown in which communication data in the frequency bands assigned to other areas can be transmitted. For example, in the in-vehicle communication system, in the relay unit 200, by changing the frequency transmitted from a certain area to the frequency band of the destination, direct transmission of communication data between areas becomes possible.

[0061] Also, in the example shown in FIG. 3A, for example, the communication data handled in the area AR1 may be configured not only for frequency division multiplexing but also for time division multiplexing. Thereby, in the relay unit 200 where the transmission capacity is the largest, it is possible to adopt a configuration that is more power-saving than switching by a router, a switch, or the like.

[0062] In the above-described first to third embodiments, a configuration is shown in which the relay unit 200 and the control unit 300 are connected by the first communication path 410. For example, the in-vehicle communication system 10 may adopt a configuration using a centralized control unit in which the relay unit 200 and the control unit 300 are integrated. Thereby, the transmission and reception of communication data in the first communication path 410 become unnecessary, and it is possible to realize a reduction in the delay of communication data transmission in the in-vehicle communication system 10.

[0063] Also, in the first embodiment, an example in which the first communication path 410 and the second communication path 420 are configured by optical fibers has been shown, but the embodiment is not limited to this configuration. For example, the first communication path 410 and / or the second communication path 420 may be configured with a metal such as a copper wire instead of an optical fiber. For example, when the first communication path 410 is configured with a metal, the E / O conversion unit 510 of the control unit 300 and the O / E conversion unit 520 of the relay unit 200 become unnecessary, and it becomes possible to reduce the device cost. Similarly, when a part or all of the second communication path 420 is configured with a metal, the E / O conversion unit 510 of the relay unit 200 connected with the metal and the O / E conversion unit 520 of the ECU 100 become unnecessary, and it becomes possible to reduce the device cost. For example, when the first communication path 410 or the second communication path 420 can be realized over a short distance, since the influence of noise is small, the device cost can be effectively reduced by configuring the first communication path 410 or the second communication path 420 with a metal.

[0064] Further, the in-vehicle communication system 10 may be configured to further include a third communication path 430 capable of communicating with a wireless access network outside the vehicle (outside the vehicle). FIG. 6A shows a configuration example in which signals transmitted and received by the antenna 500 and received broadcast waves, such as those typified by a connected car, are transmitted to the relay unit 200, the control unit 300, and / or each area via the third communication path 430. Note that the communication data transmitted via the third communication path 430 can be transmitted as an electrical signal or an optical signal, and the type thereof does not limit the configuration of the embodiment. Also, in the example shown in FIG. 6A, an example is shown in which the transmission and reception signal band for the radio wave or optical wireless received via the antenna 500 is directly allocated and transmitted. Further, as shown in FIG. 6B, the configuration may be such that signals (IF1 to IF4) frequency-converted by the ECU 100 or the control unit 300 in the area AR5 can be transmitted. With these configurations, for example, as shown in FIG. 6C, in the control unit 300, it becomes possible to manage the entire in-vehicle and out-of-vehicle networks only by frequency allocation for the communication data obtained by multiplexing the in-vehicle communication data and the out-of-vehicle communication data. That is, the in-vehicle communication system 10 can transmit the communication data transmitted via the first communication path 410 and the second communication path 420 and the communication data transmitted via the third communication path 430 with the same resource allocation.

[0065] Also, in the above-described embodiment, a configuration in which the relay unit 200 has a plurality of filter units 240 that transmit communication data in a frequency band corresponding to the second communication path 420 is shown. However, each ECU 100 may be configured to include all or part of the functions of the filter unit 240. For example, in the ECU 100, it may be configured to have a filter function for frequency division multiplexing (FDM: Frequency Division Multiplexing). Alternatively, in the ECU 100, it may be configured to have a switch for time division multiplexing (TDM: Time Division Multiplexing). Alternatively, the ECU 100 may be configured to have a filter function for frequency division multiplexing and a switch for time division multiplexing. That is, the in-vehicle communication system 10 may be configured such that the ECU 100 has a filter function for frequency division multiplexing and / or a switch for time division multiplexing. FIG. 7 shows an example of a case where the ECU 100a in the area AR1 has a configuration having a filter function for frequency division multiplexing and a switch for time division multiplexing. By having a filter function and / or a switch in the ECU 100, it is possible to prevent an increase in power consumption in the concentration of processing in the relay unit 200 and to realize an in-vehicle communication system capable of transmitting communication data in a frequency band specialized for each area.

[0066] The features of the in-vehicle communication system 10 will be described below.

[0067] The in-vehicle communication system 10 according to the first aspect is provided in a vehicle and includes a plurality of ECUs 100 to which different frequency bands are respectively assigned. Further, the in-vehicle communication system 10 includes a control unit 300 that transmits and receives communication data to and from the ECU 100. Further, the in-vehicle communication system 10 includes a relay unit 200. The relay unit 200 is connected to the control unit 300 via a first communication path 410 capable of frequency-division multiplexing and transmitting communication data corresponding to different frequency bands. The relay unit 200 is also connected to the plurality of ECUs 100 via a plurality of second communication paths 420 capable of transmitting communication data in the frequency bands respectively assigned to the plurality of ECUs 100. Further, the relay unit 200 has a plurality of filter units 240 that transmit communication data in the frequency bands corresponding to the second communication paths 420.

[0068] According to the above configuration, the in-vehicle communication system 10 can realize an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.

[0069] The in-vehicle communication system 10 according to the second aspect may further include a third communication path 430 capable of communicating with a wireless access network outside the vehicle.

[0070] According to the above configuration, the in-vehicle communication system 10 can realize an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands inside and outside the vehicle with a simple configuration.

[0071] In the in-vehicle communication system 10 according to the third aspect, the communication data transmitted via the first communication path and the second communication path and the communication data transmitted via the third communication path may be transmitted with the same resource allocation.

[0072] According to the above configuration, the in-vehicle communication system 10 can manage the entire network inside and outside the vehicle only by frequency allocation, and can realize an in-vehicle communication system capable of transmitting communication data in a plurality of frequency bands with a simple configuration.

[0073] The filter unit 240 of the in-vehicle communication system 10 according to the fourth aspect may be a passive filter composed of passive elements.

[0074] According to the above configuration, since the in-vehicle communication system 10 is composed of passive elements and has a small number of components, the circuit configuration is simple. In addition, since the passive filter does not require an external power source (external power), the in-vehicle communication system 10 can realize a network configuration with low power consumption.

[0075] The first communication path 410 and / or the second communication path 420 of the in-vehicle communication system 10 according to the fifth aspect may be composed of optical fibers.

[0076] According to the above configuration, the in-vehicle communication system 10 can realize a network configuration suitable for high-speed large-capacity communication. In addition, by configuring the first communication path 410 and the second communication path 420 with optical fibers, the in-vehicle communication system 10 can realize a network configuration with reduced influence of external noise compared to a configuration using metal for the communication path.

[0077] The control unit 300 of the in-vehicle communication system 10 according to the sixth aspect may receive transmission resource information including information about other ECUs 100 that are the destinations of communication data from the ECU 100. Further, when the control unit 300 receives the transmission resource information, the control unit 300 may set the filter value of the filter unit 240 so that the communication data transmitted from the ECU 100 can be transmitted to other ECUs 100.

[0078] According to the above configuration, in the in-vehicle communication system 10, in the transmission and reception of communication data between ECUs 100, the control unit 300 is not required, and low-latency and low-power communication can be realized between each area.

[0079] The filter unit 240 according to the seventh aspect may have its filter value set in advance so that communication data can be transmitted not only in the frequency band of the corresponding second communication path 420 but also in a frequency band having a frequency value smaller than that of the frequency band of the corresponding second communication path.

[0080] According to the above configuration, in a network configuration where not all areas need to communicate with each other, the in-vehicle communication system 10 can determine the frequency band for a predetermined area in correspondence with communication between necessary areas. Thereby, the in-vehicle communication system 10 can transmit communication data in a plurality of frequency bands with a simple configuration, and can reduce device costs and power consumption.

[0081] The ECU 100 according to the eighth aspect may have a filter function for frequency division multiplexing and / or a switch for time division multiplexing.

[0082] According to the above configuration, the in-vehicle communication system 10 can prevent an increase in power consumption in the concentration of processing in the relay unit 200 and can realize an in-vehicle communication system capable of transmitting communication data in a frequency band specialized for each area.

Explanation of Reference Numerals

[0083] 10 In-vehicle communication system 100, 100a to 100d ECU 200 Relay unit 300 Control unit 410 First communication path 420, 420a to 420d Second communication path 510 E / O conversion unit 520 O / E conversion unit

Claims

1. A plurality of ECUs provided in a vehicle and each assigned a different frequency band, a control unit that transmits and receives communication data to and from the ECU, connected to the control unit by a first communication path capable of multiplexing and transmitting the communication data corresponding to the different frequency bands, and connected to the plurality of ECUs by a plurality of second communication paths capable of transmitting the communication data in the frequency bands respectively assigned to the plurality of ECUs, and a relay unit, The relay unit has a plurality of filter units that transmit the communication data in the frequency band corresponding to the second communication path, and an in-vehicle communication system.

2. The in-vehicle communication system according to claim 1, further comprising a third communication path connecting the ECU connected to an antenna capable of communicating with a wireless access network outside the vehicle and the relay unit.

3. The in-vehicle communication system according to claim 2, wherein the frequency allocation of the communication data transmitted through the first communication path and the second communication path is the same as the frequency allocation of the communication data transmitted through the third communication path.

4. The in-vehicle communication system according to claim 1, wherein the filter unit is a passive filter composed of passive elements.

5. The in-vehicle communication system according to claim 1, wherein the first communication path and / or the second communication path is composed of an optical fiber.

6. When the control unit receives transmission resource information including information about another ECU that is the transmission destination of the communication data from the ECU, the control unit sets the filter value of the filter unit so that the communication data in the frequency band of the ECU and the communication data in the frequency band of the other ECU can be transmitted. The in-vehicle communication system according to any one of claims 1 to 5.

7. The filter unit has a filter value set in advance so as to transmit the communication data in the frequency band corresponding to the second communication path and the communication data in the frequency band having a frequency value smaller than the frequency band of the corresponding second communication path. The in-vehicle communication system according to any one of claims 1 to 5.

8. The ECU has a filter function for frequency division multiplexing and / or a switch for time division multiplexing. The in-vehicle communication system according to any one of claims 1 to 5.

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