JP7728066B2 - Communication device and communication method - Google Patents

Description

The present invention relates to a communication device and a communication method.

Various devices have been proposed in the past that communicate via wires, for example, connected to an ECU (Electronic Control Unit) installed in a vehicle via a communication bus (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2021-048439

However, in recent years, there has been a trend toward an increase in the amount of data transmitted over communication buses, for example, which has raised the risk of excessive increases in the communication load in wired communications. The above-mentioned conventional technology leaves room for further improvement in terms of reducing the communication load in wired communications.

The present invention has been made in view of the above, and has an object to provide a communication device and a communication method that can reduce the communication load in wired communication.

To solve the above problems and achieve the above objectives, the present invention provides a communication device capable of communicating with a receiving device, comprising a communication control unit. The communication control unit transmits specified data to the receiving device via wireless communication, and receives or transmits a confirmation signal confirming the transmission and reception of the specified data via wired communication.

This invention makes it possible to reduce the communication load in wired communications.

FIG. 1 is a diagram showing an overview of a communication method according to the first embodiment. FIG. 2 is a block diagram showing an example of the configuration of a communication system including a communication device according to the first embodiment. FIG. 3 is a block diagram showing an example of the configuration of the central gateway ECU. FIG. 4 is a block diagram showing an example of the configuration of an in-vehicle ECU. FIG. 5 is a flowchart showing a processing procedure executed by the central gateway ECU. FIG. 6 is a block diagram showing an example of the configuration of a transmitting ECU according to the second embodiment. FIG. 7 is a diagram illustrating the transmission of predetermined data and an authentication signal. FIG. 8 is a block diagram showing an example of the configuration of a receiver ECU according to the second embodiment. FIG. 9 is a diagram illustrating an example of a processing sequence executed by the communication system according to the second embodiment.

Embodiments of the communication device, communication system, and communication method disclosed herein will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

(First embodiment)
<Communication method overview>
First, an outline of a communication method by a communication device according to the first embodiment will be described below with reference to Fig. 1. Fig. 1 is a diagram showing an outline of the communication method according to the first embodiment.

The communication method according to the first embodiment is executed, for example, by a communication device 10 included in a communication system 1. Note that the communication system 1 is mounted on a vehicle (not shown), but is not limited to this and may also be mounted on other types of devices that perform communication processing, for example.

As shown in FIG. 1, the communication system 1 includes a communication device 10 and an on-board ECU 50. The on-board ECU 50 is an example of a receiving device, and is a device that receives various data, etc. from the communication device 10, as described below. Note that the receiving device has at least a (wireless) receiving function, but may also have other functions (e.g., wireless/wired transmission function, data processing function, control function, etc.).

A vehicle may be equipped with multiple on-board ECUs 50. While FIG. 1 shows an example in which there are two on-board ECUs 50 for the sake of simplicity, the number of on-board ECUs 50 is not limited to this and may be three or more, or may be one. The on-board ECU 50 may perform, for example, processing related to vehicle control, but is not limited to this.

The communication device 10 and the multiple on-board ECUs 50 are connected via an on-board network. Specifically, the communication device 10 and the multiple on-board ECUs 50 are connected via a communication bus (communication line) B, such as a CAN (Controller Area Network) bus, and are configured to enable wired communication.

In recent years, wired communication using the above-mentioned communication bus B has tended to increase data communication volume, which could result in an excessive increase in communication load. Specifically, a vehicle is configured to be able to communicate with, for example, an external server device 210 (see FIG. 2, described below), and can acquire various information such as map information and traffic information distributed from the server device 210. Since some or all of the above-mentioned various information may be transmitted to the on-board ECU 50, etc., via communication bus B, there is a risk that the communication load of wired communication using communication bus B could increase excessively.

Therefore, the communication device 10 according to this embodiment is configured to reduce the communication load in wired communication.

Specifically, the communication device 10 is configured to be capable of wireless communication with the on-board ECU 50. In other words, the communication device 10 is configured to be able to communicate with the on-board ECU 50 via both wired and wireless communication. Note that, while the wireless communication method may be, for example, Wi-Fi (registered trademark) or Bluetooth (registered trademark), it is not limited to these, and other types of communication methods may also be used.

The communication device 10 according to this embodiment first acquires predetermined data to be transmitted to the vehicle ECU 50 (step S1). The predetermined data is, for example, data that is transmitted simultaneously to multiple vehicle ECUs 50. As an example, the predetermined data may include some or all of the data indicating the rotation speed of the vehicle's engine, electric motor, or other driving source, vehicle speed, vehicle status (e.g., brake or steering status), coolant temperature, etc.

In the above description, the specified data is data that is sent simultaneously to multiple on-board ECUs 50, but this is not limited to this and may be data that is sent to each on-board ECU 50 at individual times, for example. In addition, while the above description specifically shows the content of the specified data, this is merely an example and is not limiting, and the data can be set to any data.

Next, the communication device 10 transmits the specified data to the in-vehicle ECUs 50 via wireless communication (step S2). Specifically, the communication device 10 transmits the specified data to multiple in-vehicle ECUs 50 simultaneously via wireless communication.

When the on-board ECU 50 receives the specified data transmitted from the communication device 10, it generates a confirmation signal to confirm the transmission and reception (more specifically, reception) of the specified data (step S3). More specifically, when the multiple on-board ECUs 50 receive the specified data, they each generate a confirmation signal. Here, the confirmation signal is a response signal (e.g., an ACK (acknowledgement)) that is used by the communication device 10 to confirm that the specified data has been successfully received by the on-board ECU 50.

Then, the communication device 10 receives the confirmation signal generated by the on-board ECU 50 via wired communication (step S4). That is, the on-board ECU 50 transmits the generated confirmation signal to the communication device 10 via wired communication (specifically, via communication bus B) at a predetermined timing, and the communication device 10 receives the confirmation signal. By receiving this confirmation signal, the communication device 10 confirms that the on-board ECU 50 has successfully received the predetermined data.

In this way, the communication device 10 according to this embodiment transmits predetermined data to the on-board ECU 50 via wireless communication, and receives confirmation signals transmitted from the on-board ECU 50 via wired communication.

As a result, in this embodiment, the communication load in wired communication can be reduced. In other words, by transmitting the specified data wirelessly, the communication load in wired communication can be reduced by the amount of data communication of the specified data, compared to when the specified data is transmitted via wired communication, for example.

In addition, in this embodiment, data that incurs a relatively large communication load, such as data that is transmitted simultaneously to multiple on-board ECUs 50, is defined as the specified data, and the transmission of such specified data is performed wirelessly, thereby making it possible to further reduce the communication load of wired communication.

<Communication system including communication device>
Next, the configuration of a communication system 1 including the communication device 10 according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the configuration of the communication system 1 including the communication device 10 according to the first embodiment.

As shown in FIG. 2, the communication system 1 includes the above-described communication device 10, an in-vehicle ECU 50, a sensor 100, a connected gateway ECU 200, and a server device 210.

In this embodiment, the communication device 10 is realized by a central gateway ECU. That is, the central gateway ECU is an example of the communication device 10. In the following, the central gateway ECU functioning as the communication device 10 may be referred to as a CGW (Central Gateway) ECU 10. The detailed configuration of the CGW ECU 10 will be described later with reference to Figure 3.

The connected gateway ECU 200 is communicatively connected to the CGWECU 10. The connected gateway ECU 200 and the server device 210 are communicatively connected via a communication network N such as the Internet.

As described above, server device 210 is a server device that can distribute various information such as map information, traffic information, and weather information.

The connected gateway ECU 200 is equipped with an in-vehicle communication module such as a DCM (Data Communication Module) and communicates with the server device 210. For example, the connected gateway ECU 200 can acquire various information distributed from the server device 210 and transmit the acquired information to the in-vehicle ECU 50, etc. via the CGWECU 10 and communication bus B.

The CGWECU 10 is also communicatively connected to the on-board ECUs 50 via a communication bus B. More specifically, multiple communication buses B are connected to the CGWECU 10. Multiple on-board ECUs 50 are connected to each of the multiple communication buses B. In other words, the CGWECU 10 can relay data transmission and reception between the on-board ECUs 50.

In the example of Figure 2, of the multiple communication buses B, communication bus Ba is a powertrain system bus, and powertrain system onboard ECUs 50a1, 50a2, and 50a3 are connected to this communication bus Ba. Furthermore, communication bus Bb is a chassis system bus, and chassis system onboard ECUs 50b1, 50b2, and 50b3 are connected to this communication bus Bb.

In the following, when communication buses Ba and Bb are described without any particular distinction, they will be referred to as "communication bus B," and when on-board ECUs 50a1-a3 and 50b1-b3 are described without any particular distinction, they will be referred to as "on-board ECU 50."

Furthermore, while Figure 2 shows an example in which the types of communication bus B and on-board ECU 50 are powertrain and chassis systems, this is not limited thereto and other types of communication bus B and on-board ECU 50, such as body systems, may also be included. Furthermore, the number of communication buses B and on-board ECUs 50 shown in Figure 2 is merely an example and is not limited thereto, and can be set to any number. The detailed configuration of the on-board ECU 50 will be described later with reference to Figure 4.

Sensor 100 is, for example, one of various sensors required for vehicle control. There are multiple sensors 100, and for example, sensor 100a among the multiple sensors 100 is a rotation speed sensor that outputs a signal indicating the rotation speed of the drive source to on-board ECU 50 (on-board ECU 50a1 in the example of Figure 2). On-board ECU 50a1 can output the signal output from sensor 100a to, for example, CGW ECU 10.

For example, sensor 100b is a brake sensor that outputs a signal indicating the state of the brake, such as the amount of depression of a brake pedal (not shown), to the on-board ECU 50 (on-board ECU 50b1 in the example of Figure 2). The on-board ECU 50b1 can output the signal output from sensor 100b to, for example, the CGW ECU 10.

In the following, when sensors 100a and 100b are described without any particular distinction, they will be referred to as "sensor 100." Furthermore, while Figure 2 shows an example in which the sensor 100 is a rotation speed sensor or a brake sensor, this is not limited to this and other types of sensors 100 may be included, such as a vehicle speed sensor, a steering angle sensor, or a coolant temperature sensor. Furthermore, the number of sensors 100 shown in Figure 2 is merely an example and is not limited to any particular number, and can be set to any number.

<Configuration of CGWECU (Central Gateway ECU)>
Next, the configuration of the CGWECU 10 will be specifically described with reference to Fig. 3. Fig. 3 is a block diagram showing an example of the configuration of the CGWECU 10. Note that in the block diagrams such as Fig. 3, only the components necessary for explaining the features of this embodiment are shown as functional blocks, and descriptions of general components are omitted.

In other words, the components shown in block diagrams such as Figure 3 are conceptual functional components and do not necessarily have to be physically configured as shown. For example, the specific form of distribution and integration of each functional block is not limited to that shown, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

As shown in Figure 3, the CGWECU 10 includes a wireless communication unit 11, a wired communication unit 12, a control unit 20, and a memory unit 30.

The wireless communication unit 11 is a communication interface that connects to the on-board ECU 50 via wireless communication to enable bidirectional communication, and transmits and receives various data, including predetermined data, to and from the on-board ECU 50.

The wired communication unit 12 is a communication interface that connects to the on-board ECU 50 via wired communication using a communication bus B (see Figure 2) or the like, enabling bidirectional communication, and transmits and receives various data, including confirmation signals, between the on-board ECU 50 and the on-board ECU 50.

The control unit 20 includes an acquisition unit 21 and a communication control unit 22, and includes a computer and various circuits, including, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), a hard disk drive, input/output ports, etc.

The computer's CPU functions as the acquisition unit 21 and communication control unit 22 of the control unit 20, for example, by reading and executing programs stored in the ROM.

Furthermore, at least part of or all of the acquisition unit 21 and communication control unit 22 of the control unit 20 can be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

The storage unit 30 is composed of a storage device such as a non-volatile memory, data flash, or hard disk drive. The storage unit 30 stores predetermined data 31 and various programs.

As described above, the predetermined data 31 is data to be transmitted to the on-board ECU 50. For example, the predetermined data 31 includes data that is transmitted simultaneously to multiple on-board ECUs 50 (such as the rotation speed of the drive source), but is not limited to this.

The acquisition unit 21 of the control unit 20 acquires specified data. The acquisition unit 21 stores the acquired data in the memory unit 30 as specified data 31. For example, when acquiring the rotation speed of the drive source as the specified data, the acquisition unit 21 acquires a signal indicating the rotation speed of the drive source from the sensor 100a via the on-board ECU 50a1 (see Figure 2 for both). In this case, the acquisition unit 21 acquires the signal indicating the rotation speed of the drive source via wired communication, but this is not limited to this and the signal may also be acquired via wireless communication. The acquisition unit 21 then stores the acquired rotation speed of the drive source as specified data 31 in the memory unit 30.

The communication control unit 22 transmits predetermined data to the on-board ECU 50 via wireless communication. For example, the communication control unit 22 reads predetermined data 31 from the memory unit 30 and transmits the read data via wireless communication to the on-board ECU 50 via the wireless communication unit 11.

In this way, by transmitting the specified data wirelessly, the communication load in wired communication can be reduced by the amount of data communication of the specified data, compared to when the specified data is transmitted via wired communication, for example.

The communication control unit 22 also transmits the specified data to multiple in-vehicle ECUs 50 (in-vehicle ECUs 50a1-a3, 50b1-b3) simultaneously via wireless communication. In other words, the communication control unit 22 broadcasts the specified data to multiple in-vehicle ECUs 50 via wireless communication.

In this way, data that incurs a relatively large communication load, such as data that is transmitted simultaneously to multiple in-vehicle ECUs 50, is designated as the specified data, and transmission of such specified data is performed wirelessly, thereby making it possible to further reduce the communication load of wired communication.

As described above, when the on-board ECU 50 receives the specified data, it generates a confirmation signal to confirm the transmission and reception (more specifically, reception) of the specified data, and transmits the generated confirmation signal to the CGWECU 10 via wired communication. This confirmation signal is a response signal (ACK) that allows the CGWECU 10 to confirm that the specified data has been successfully received by the on-board ECU 50.

Therefore, the communication control unit 22 receives the confirmation signal generated by the on-board ECU 50 via wired communication. In other words, the communication control unit 22 receives a response signal (ACK) from the on-board ECU 50 via the wired communication unit 12 as a confirmation signal to confirm that the specified data has been received by the on-board ECU 50. Then, by receiving this response signal (confirmation signal), the communication control unit 22 can confirm that the specified data has been successfully received by the on-board ECU 50.

However, there may be some problem that prevents the transmission or reception of the specified data from occurring normally. In this embodiment, even if such a problem occurs, it is possible to respond appropriately.

Specifically, if the status of reception of the response signal (confirmation signal) satisfies predetermined conditions, the communication control unit 22 may retransmit the specified data to the in-vehicle ECU 50 via wireless communication. As a result, even if the previous transmission or reception of the specified data was not performed normally, retransmitting the specified data may result in the specified data being transmitted and received normally, thereby making it possible to respond appropriately to the above-mentioned events.

More specifically, the communication control unit 22 transmits predetermined data to multiple on-board ECUs 50, and then waits for a response signal to be returned from each on-board ECU 50. For example, after transmitting the predetermined data, the communication control unit 22 accepts a response signal for a predetermined period of time.

The specified period is set, for example, to the period from when the CGW ECU 10 and the on-board ECUs 50 are both normal and when the specified data is transmitted until it is assumed that response signals are returned from all on-board ECUs 50 to which the specified data was transmitted, but it is not limited to this and can be set to any period.

After receiving response signals for a predetermined period of time, the communication control unit 22 calculates the response signal response rate. For example, the communication control unit 22 calculates the proportion of on-board ECUs 50 that have returned response signals to all on-board ECUs 50 to which predetermined data has been transmitted, i.e., the response signal response rate.

The communication control unit 22 compares the calculated response signal response rate with a predetermined value. If the response rate is equal to or less than the predetermined value and there is sufficient time to transmit, the communication control unit 22 retransmits the specified data to the on-board ECU 50 via wireless communication. In other words, the condition that the response rate is equal to or less than the predetermined value and there is sufficient time to transmit is an example of the above-mentioned predetermined condition.

The predetermined value is set to a value that, if the response rate is below that value, indicates that some problem occurred when the specified data was transmitted wirelessly. More specifically, the predetermined value is set to a value that indicates that the specified data did not reach some or all of the multiple on-board ECUs 50, for example, due to the influence of temporary harmful radio waves. The predetermined value is not limited to the above, and can be set to any value less than 100%, for example.

In addition, the transmission margin time indicates the amount of time available to resend previously transmitted specified data via wireless communication before the next transmission of new specified data (more specifically, new specified data that is different from the previously transmitted specified data).

Therefore, if the response rate is below a predetermined value and there is sufficient transmission time, the communications control unit 22 will resend the specified data via wireless communication. This means that even if, for example, some problem occurred the last time the specified data was sent and the specified data was not sent or received properly, the resending may result in the specified data being sent and received properly, making it possible to respond appropriately to the above-mentioned events.

Note that if the response rate is 100%, i.e., if a response signal has been returned from all on-board ECUs 50 to which the specified data was transmitted, the communication control unit 22 will not perform processing such as retransmitting the specified data as described above.

Furthermore, if a response signal is not received (replied), the communication control unit 22 may transmit predetermined data via wired communication to the in-vehicle ECU 50 that is not receiving (replying) a response signal, i.e., may switch from wireless communication to wired communication and transmit the predetermined data.

As a result, even if specified data cannot be sent or received normally via wireless communication, it may be possible to send and receive the specified data normally by sending it via wired communication, thereby making it possible to respond appropriately to the above-mentioned events.

Specifically, for example, if the specified data reaches a certain number of the multiple on-board ECUs 50 but does not reach some of the on-board ECUs 50, the communication control unit 22 assumes that there is a problem on the receiving side of the wireless communication of the specified data, rather than a problem on the sending side of the wireless communication of the specified data, and transmits the specified data via wired communication to the on-board ECUs 50 that do not receive (reply from) a response signal.

More specifically, if the response rate is greater than a predetermined value but less than 100%, the communication control unit 22 assumes that a problem has occurred on the receiving side of the wireless communication of the predetermined data, and transmits the predetermined data via wired communication to the on-board ECU 50 that is not receiving (replying from) a response signal.

Furthermore, if a response signal is not received (reply) and there is no transmission margin time as described above, the communication control unit 22 may transmit predetermined data via wired communication to the in-vehicle ECU 50 that did not receive the response signal. In other words, if, for example, the response rate is less than 100% and there is no margin to resend the predetermined data via wireless communication, the communication control unit 22 may transmit predetermined data via wired communication to the in-vehicle ECU 50 that did not receive the response signal.

In this way, even if the communication control unit 22 does not receive a response signal and the specified data is not sent or received normally via wireless communication, the specified data may be sent and received normally by sending it via wired communication, thereby making it possible to respond appropriately to the above-mentioned events.

In addition, in this embodiment, the specified data is transmitted via wired communication only to on-board ECUs 50 that do not receive (reply from) a response signal, thereby minimizing the increase in communication load in wired communication as much as possible.

Note that even when the above-mentioned specified data is transmitted via wired communication, the communication control unit 22 may perform anomaly handling processing if the transmission or reception of the specified data is not performed normally. For example, the communication control unit 22 may perform anomaly handling processing if the transmission of the specified data via wired communication satisfies the anomaly handling processing conditions.

Note that the above-mentioned abnormality handling processing conditions may be, for example, when specified data is not sent or received normally even after being sent via wired communication once or multiple times, but are not limited to this and can be set to any condition.

Furthermore, examples of abnormality response processing include temporarily halting the transmission of specified data to the onboard ECU 50 that is not receiving a response signal, or outputting a diagnostic, but these are merely examples and are not limiting, and any processing content can be set.

<Configuration of the on-board ECU>
Next, the configuration of the in-vehicle ECU 50 will be specifically described with reference to Fig. 4. Fig. 4 is a block diagram showing an example configuration of the in-vehicle ECU 50. As shown in Fig. 4, the in-vehicle ECU 50 includes a wireless communication unit 51, a wired communication unit 52, a control unit 60, and a storage unit 70.

The wireless communication unit 51 is a communication interface that connects to the CGWECU 10 via wireless communication to enable bidirectional communication, and transmits and receives various data, including predetermined data, to and from the CGWECU 10.

The wired communication unit 52 is a communication interface that connects to the CGWECU 10 via wired communication using a communication bus B (see Figure 2) or the like, enabling bidirectional communication, and transmits and receives various data, including confirmation signals (response signals), between the CGWECU 10 and the CGWECU 10.

The control unit 60 includes a transceiver unit 61 and a processing unit 62, and includes, for example, a computer with a CPU, ROM, RAM, hard disk drive, input/output ports, and various other circuits. The computer's CPU functions as the transceiver unit 61 and processing unit 62 of the control unit 60, for example, by reading and executing a program stored in ROM. Furthermore, at least some or all of the transceiver unit 61 and processing unit 62 of the control unit 60 can also be configured using hardware such as an ASIC or FPGA.

The storage unit 70 is composed of a storage device such as a non-volatile memory, data flash, or hard disk drive. Various programs and the like are stored in the storage unit 70.

When the transceiver 61 of the control unit 60 receives the specified data transmitted from the CGWECU 10, it generates a confirmation signal. More specifically, when the transceiver 61 receives the specified data transmitted by wireless communication from the CGWECU 10 via the wireless communication unit 51, it generates a response signal (confirmation signal).

The transmitter/receiver 61 then transmits (replies to) the generated response signal via wired communication to the CGWECU10 at a predetermined timing. Note that the predetermined timing is set, for example, to the timing at which the on-board ECU 50 transmits data to the CGWECU10. This data is different from the response signal, and may be, for example, data used by the CGWECU10 or data sent to and used by another on-board ECU 50 via the CGWECU10, but is not limited to these.

In this way, the transmitter/receiver 61 transmits a response signal along with the data at the same time that the data is transmitted via wired communication. Note that the specified timing is not limited to the timing of transmitting the data described above, and can be set to any timing.

As described above, the CGWECU10 accepts a response signal for a predetermined period of time after transmitting the specified data. However, if there is no data to transmit to the CGWECU10 before the predetermined period has elapsed, the transceiver unit 61 may transmit only the response signal to the CGWECU10 via wired communication.

In the above description, the transceiver 61 is configured to receive specified data transmitted by wireless communication from the CGWECU 10, but it can also generate a response signal and transmit (reply) it to the CGWECU 10 when it receives specified data transmitted by wired communication from the CGWECU 10.

The processing unit 62 performs various processes related to vehicle control based on the received specified data.

<Control process of CGW ECU according to the first embodiment>
Next, a specific processing procedure in the CGWECU (communication device) 10 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the processing procedure executed by the CGWECU (communication device) 10.

As shown in FIG. 5, the control unit 20 of the CGW ECU 10 acquires predetermined data to be transmitted to the on-board ECU 50 (step S10). Next, the control unit 20 transmits the predetermined data to the on-board ECU 50 via wireless communication (step S11).

Next, the control unit 20 accepts response signals from the on-board ECUs 50 for a predetermined period of time (step S12). Next, the control unit 20 calculates the response signal response rate and determines whether the calculated response rate is 100% (step S13). In other words, the processing of step S13 is processing to determine whether response signals have been returned from all on-board ECUs 50 to which the predetermined data was transmitted.

If the response signal return rate is 100% (Step S13, Yes), the control unit 20 ends the process and waits until the next timing to start the process of transmitting new specified data.

On the other hand, if the response signal return rate is not 100% (step S13, No), the control unit 20 then determines whether the response signal return rate is below a predetermined value and whether there is sufficient transmission time (step S14).

If the response signal return rate is equal to or less than the predetermined value and there is sufficient transmission time (step S14, Yes), the control unit 20 retransmits the specified data to the on-board ECU 50 via wireless communication (step S15). The control unit 20 then returns to step S12 and waits for a response signal from the on-board ECU 50.

On the other hand, if the response signal return rate is not below the predetermined value, or if there is no transmission margin (step S14, No), the control unit 20 determines whether the transmission of the specified data via wired communication satisfies the abnormality response processing conditions (step S16).

When the control unit 20 first executes the process of step S16, it determines that the abnormality response processing conditions are not met because the specified data has not been transmitted via wired communication (step S16, No), and transmits the specified data via wired communication to the on-board ECU 50 that has not received (returned) a response signal (step S17). The control unit 20 then returns to the process of step S12 and waits for a response signal to be returned from the on-board ECU 50.

Next, if the control unit 20 determines that the transmission of the specified data via wired communication satisfies the abnormality response processing conditions (step S16, Yes), in other words, if the specified data is not transmitted or received normally even when transmitted via wired communication, it executes abnormality response processing (step S18) and terminates the process.

As described above, the CGWECU (an example of a communication device) 10 according to the first embodiment is configured to be able to communicate with the on-board ECU (an example of a receiving device) 50. The CGWECU 10 also includes a communication control unit 22 that transmits predetermined data to the on-board ECU 50 via wireless communication and receives confirmation signals (response signals) confirming the transmission and reception (more specifically, reception) of the predetermined data via wired communication. This reduces the communication load associated with wired communication.

Second Embodiment
Next, a second embodiment will be described with reference to Fig. 2. In the following, components common to the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 2, in communication system 1, multiple on-board ECUs 50 are connected via communication bus B to enable wired communication. In the second embodiment, the communication system is configured to reduce the communication load in wired communication between multiple on-board ECUs 50.

In the following, as an example, it is assumed that, of the multiple on-board ECUs 50, on-board ECU 50b1 transmits data, and such on-board ECU 50b1 will be referred to as the "sending ECU 50b1." Furthermore, it is assumed that on-board ECU 50b2 receives the data transmitted from the sending ECU 50b1, and such on-board ECU 50b2 will be referred to as the "receiving ECU 50b2." Note that in the second embodiment, sending ECU 50b1 is an example of a communication device, and receiving ECU 50b2 is an example of a receiving device.

Furthermore, in the following, the transmitting ECU 50b1 will be described as having a data transmitting function, and the receiving ECU 50b2 will be described as having a data receiving function, so they will be described as having different configurations. However, this is for ease of understanding and is not a limitation. That is, the on-board ECU 50b2 may transmit data, in which case the on-board ECU 50b2 functions as the "sending ECU." Also, the on-board ECU 50b1 may receive data transmitted from the on-board ECU 50b2, in which case the on-board ECU 50b1 functions as the "receiving ECU." That is, any of the multiple on-board ECUs 50 may be configured to have the functions of both a "sending ECU" and a "receiving ECU."

<Configuration of the transmitting ECU>
First, the configuration of the transmitter ECU 50b1 will be specifically described with reference to Fig. 6. Fig. 6 is a block diagram showing an example of the configuration of the transmitter ECU 50b1 according to the second embodiment. As shown in Fig. 6, the transmitter ECU 50b1 includes a wireless communication unit 51, a wired communication unit 52, a control unit 60b1, and a storage unit 70b1.

The wireless communication unit 51 is a communication interface that connects to the receiving ECU 50b2 via wireless communication to enable bidirectional communication, and transmits and receives various data, including predetermined data, between the receiving ECU 50b2 and the receiving ECU 50b2.

The wired communication unit 52 is a communication interface that connects to the receiving ECU 50b2 via wired communication using a communication bus B (see Figure 2) or the like, enabling bidirectional communication, and transmits and receives various data, including confirmation signals, between the receiving ECU 50b2 and the receiving ECU 50b2.

The control unit 60b1 includes an acquisition unit 61b1 and a communication control unit 62b1, and includes, for example, a computer with a CPU, ROM, RAM, a hard disk drive, input/output ports, and various other circuits. The computer's CPU functions as the acquisition unit 61b1 and communication control unit 62b1 of the control unit 60b1, for example, by reading and executing a program stored in ROM. Furthermore, at least some or all of the acquisition unit 61b1 and communication control unit 62b1 of the control unit 60b1 can also be configured using hardware such as an ASIC or FPGA.

The storage unit 70b1 is configured with a storage device such as a non-volatile memory, data flash, or hard disk drive. This storage unit 70b1 stores predetermined data 71b1 and various programs.

The predetermined data 71b1 is data to be transmitted to the receiving ECU 50b2. The predetermined data 71b1 includes, for example, relatively important data (such as the brake status) that is accompanied by a confirmation signal, but is not limited to this. Here, the confirmation signal in the second embodiment is an authentication signal (e.g., a MAC (Message Authentication Code)) that the receiving ECU 50b2 uses to confirm the authenticity of the predetermined data; in other words, it is a signal that confirms the transmission and reception (more specifically, transmission) of the predetermined data.

The acquisition unit 61b1 of the control unit 60b1 acquires specified data. The acquisition unit 61b1 stores the acquired data in the memory unit 70b1 as specified data 71b1. For example, when acquiring the brake status as the specified data, the acquisition unit 61b1 acquires a signal indicating the brake status from the sensor 100b (see Figure 2) and stores the acquired brake status in the memory unit 70b1 as specified data 71b1.

The communication control unit 62b1 transmits specified data to the receiving ECU 50b2 via wireless communication and transmits an authentication signal (confirmation signal) for the specified data via wired communication. For example, the communication control unit 62b1 reads specified data 71b1 from the memory unit 70b1, transmits the read data via wireless communication via the wireless communication unit 51, and transmits an authentication signal for confirming the authenticity of the specified data via wired communication via the wired communication unit 52.

The transmission of the above-mentioned specified data and authentication signal will be explained in detail with reference to Figure 7. Figure 7 is a diagram explaining the transmission of the specified data and authentication signal. Note that in Figure 7, the upper part shows a comparative example in which the specified data and authentication signal are both transmitted via wired communication, while the lower part shows an example in the second embodiment in which the specified data is transmitted via wireless communication and the authentication signal is transmitted via wired communication.

As shown in the upper part of Figure 7, the transmission data Da in the comparative example includes a header, predetermined data, and an authentication signal (MAC), and is transmitted via wired communication. In this way, if all of the transmission data Da from the transmitting ECU 50b1 to the receiving ECU 50b2 is transmitted via wired communication, the amount of data communication on the communication bus B (see Figure 2) increases, increasing the communication load in the wired communication.

In the second embodiment, as shown in the lower part of Figure 7, transmission data Da is divided into transmission data D1, which includes a header, predetermined data, and an index value, and transmission data D2, which includes an index value and an authentication signal, and transmission data D1 is transmitted via wireless communication and transmission data D2 is transmitted via wired communication.

The index value mentioned above is information that links transmission data D1 and transmission data D2. In other words, the receiving ECU 50b2 can link and correspond transmission data D1 and D2 by comparing the index value contained in transmission data D1 with the index value contained in transmission data D2. The index value can be, but is not limited to, a time (e.g., transmission time) or a timer value of the sending ECU 50b1. The data communication volume of the index value is assumed to be smaller than the data communication volume of the specified data and header.

In this way, in the second embodiment, transmission data D1 including the specified data is transmitted to the receiving ECU 50b2 via wireless communication, and transmission data D2 including the authentication signal is transmitted via wired communication. This makes it possible to reduce the communication load in wired communication by the amount of data communication of the specified data (more precisely, by the amount of data communication of the specified data and header) compared to, for example, when transmission of the specified data is performed via wired communication, as in the comparative example.

Continuing with the explanation of Figure 6, the communication control unit 62b1 transmits the authentication signal as a confirmation signal to the receiving ECU 50b2 as described above. As a result, the receiving ECU 50b2 can receive the authentication signal and confirm the validity of the specified data associated with the authentication signal.

Here, for example, it may happen that either the transmission data D1 or the transmission data D2 described above is not received by the receiving ECU 50b2 due to some problem. In such a case, the receiving ECU 50b2 performs processing to request retransmission of the transmission data D1 containing the specified data that was not received, or the transmission data D2 containing the authentication signal that was not received.

Therefore, when a retransmission request is made by the receiving ECU 50b2, in other words, when the corresponding specified data (transmission data D1) and authentication signal (transmission data D2) have not been received by the receiving ECU 50b2, the communication control unit 62b1 will retransmit the unreceived specified data (transmission data D1) or unreceived authentication signal (transmission data D2) to the receiving ECU 50b2.

This allows the receiving ECU 50b2 to receive the specified data or authentication signal that has not been received.

For example, if the specified data is retransmitted but not received by the receiving ECU 50b2, the communication control unit 62b1 may assume that there is a problem with the wireless communication and may transmit the specified data via wired communication. For example, if the authentication signal is retransmitted but not received by the receiving ECU 50b2, the communication control unit 62b1 may assume that there is a problem with the wired communication and may transmit the authentication signal via wireless communication. This increases the likelihood that the specified data or the authentication signal will be received normally by the receiving ECU 50b2.

<Configuration of Receiving ECU>
Next, the configuration of the receiver ECU 50b2 will be specifically described with reference to Fig. 8. Fig. 8 is a block diagram showing an example of the configuration of the receiver ECU 50b2 according to the second embodiment. As shown in Fig. 8, the receiver ECU 50b2 includes a wireless communication unit 51, a wired communication unit 52, a control unit 60b2, and a storage unit 70b2.

The wireless communication unit 51 is a communication interface that connects to the transmitting ECU 50b1 via wireless communication to enable bidirectional communication, and transmits and receives various data, including predetermined data, between the transmitting ECU 50b1 and the transmitting ECU 50b1.

The wired communication unit 52 is a communication interface that connects to the sending ECU 50b1 via wired communication using a communication bus B (see Figure 2) or the like to enable bidirectional communication, and transmits and receives various data, including confirmation signals (authentication signals), between the sending ECU 50b1 and the sending ECU 50b1.

The control unit 60b2 includes a transceiver unit 61b2 and a processing unit 62b2, and includes, for example, a computer with a CPU, ROM, RAM, a hard disk drive, input/output ports, and various other circuits. The computer's CPU functions as the transceiver unit 61b2 and processing unit 62b2 of the control unit 60b2, for example, by reading and executing a program stored in ROM. Furthermore, at least some or all of the transceiver unit 61b2 and processing unit 62b2 of the control unit 60b2 can also be configured using hardware such as an ASIC or FPGA.

The storage unit 70b2 is configured with a storage device such as a non-volatile memory, data flash, or hard disk drive. Various programs and the like are stored in the storage unit 70b2.

The transceiver 61b2 of the control unit 60b2 receives transmission data D1, which includes predetermined data and is transmitted from the transmitting ECU 50b1, via the wireless communication unit 51. The transceiver 61b2 also receives transmission data D2, which includes an authentication signal and is transmitted from the transmitting ECU 50b1, via the wired communication unit 52.

The transmitter/receiver 61b2 compares the index value included in the transmission data D1 with the index value included in the transmission data D2, and if they match, associates and corresponds the transmission data D1 and D2.

The transmitter/receiver 61b2 also confirms the authenticity of the specified data associated with the authentication signal based on the authentication signal. The transmitter/receiver 61b2 outputs the specified data whose authenticity has been confirmed to the processing unit 62b2.

In addition, if the transmitter/receiver 61b2 receives either the specified data or the authentication signal, but does not receive the corresponding specified data (transmission data D1) or authentication signal (transmission data D2), the transmitter/receiver 61b2 requests the transmitting ECU 50b1 to resend the transmission data D1 containing the specified data that has not been received, or the transmission data D2 containing the authentication signal that has not been received.

The processing unit 62b2 performs various processes related to vehicle control based on the specified data whose validity has been confirmed.

<Control process of communication system according to second embodiment>
Next, a processing procedure executed by the communication system 1 according to the second embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram showing an example of a processing sequence executed by the communication system 1 according to the second embodiment.

As shown in FIG. 9, the control unit 60b1 of the transmitting ECU 50b1 acquires predetermined data to be transmitted to the receiving ECU 50b2 (step S20). Next, the control unit 60b1 transmits the predetermined data (transmission data D1) via wireless communication and transmits an authentication signal (transmission data D2) via wired communication (step S21).

Next, the control unit 60b2 of the receiving ECU 50b2 performs a reception determination process to determine whether the corresponding predetermined data (transmission data D1) and authentication signal (transmission data D2) have been received (step S22). If the control unit 60b2 determines that the corresponding predetermined data and authentication signal have been received, it performs various processes related to vehicle control using the predetermined data, as described above.

If the corresponding specified data and authentication signal have not been received, the control unit 60b2 requests the transmitting ECU 50b1 to retransmit the unreceived specified data or unreceived authentication signal (step S23).

When a retransmission request is made, the receiving ECU 50b2 retransmits the unreceived specified data or unreceived authentication signal to the receiving ECU 50b2 (step S24).

In this way, the transmitting ECU (an example of a communication device) 50b1 according to the second embodiment is configured to be able to communicate with the receiving ECU (an example of a receiving device) 50b2. The transmitting ECU 50b1 also includes a communication control unit 62b1 that transmits predetermined data to the receiving ECU 50b2 via wireless communication and transmits a confirmation signal (authentication signal) confirming the transmission and reception (more specifically, transmission) of the predetermined data via wired communication. This reduces the communication load in wired communication.

In addition, in the first and second embodiments described above, data for confirming whether or not specific data has been sent or received (e.g., confirmation signals (response signals or authentication signals)) is transmitted via wired communication, so information on whether or not data has been sent or received and confirmation information is transmitted reliably. In other words, if, for example, information on whether or not data has been sent or received and confirmation information were transmitted wirelessly, in a noisy environment or the like, it could become unclear whether or not the actual data was sent or whether or not data has been sent or confirmation information was sent, which could result in confusion or unnecessary retransmissions (for example, a situation could arise in which the confirmation signal is not transmitted even though data has been received correctly). In the first and second embodiments, by using wired communication as described above, it is possible to prevent such events from occurring.

Furthermore, when a wireless-wireless loop is used, both paths are susceptible to noise and other factors. Therefore, if a data transmission/reception error occurs, it is unclear which wireless path the error occurred on, which makes it difficult to estimate, and it may be difficult to take appropriate action. In the first and second embodiments, a wireless-wired loop is used, so it is possible to almost certainly infer that the error is wireless.

In each of the above-described embodiments, the CGW ECU 10 and the on-board ECU 50 are communicatively connected via a communication bus B, but this is not limited thereto; they may also be communicatively connected via power line communication (PLC), for example.

Furthermore, in the first embodiment described above, if a response signal is not received, the specified data is transmitted via wired communication only to the on-board ECU 50 that does not receive the response signal. However, this is not limited to this, and, for example, the specified data may also be transmitted via wired communication to the on-board ECU 50 that has received the response signal.

In addition, in the second embodiment described above, the specified data is transmitted via wireless communication and the authentication signal is transmitted via wired communication, but this is not limited to this. For example, some or all of the specified data may be transmitted via wired communication and some or all of the authentication signal may be transmitted via wireless communication.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

1 Communication system 10 CGWECU
50 In-vehicle ECU
22, 62b1 Communication control unit

Claims (3)

A communication device capable of communicating with a receiving device, the communication device having a control unit,
The control unit
transmitting predetermined data to the receiving device via wireless communication;
receiving a response signal from the receiving device via wired communication to confirm that the predetermined data has been received by the receiving device;
If the response signal is not received, the predetermined data is transmitted to the receiving device via wired communication.
Communication equipment. the receiving device is a plurality of devices,
The control unit
transmitting the predetermined data to the plurality of receiving devices simultaneously via wireless communication;
The communication device according to claim 1 . A communication method performed by a communication device,
transmitting predetermined data to a receiving device via wireless communication;
receiving a response signal from the receiving device via wired communication to confirm that the predetermined data has been received by the receiving device;
If the response signal is not received, the predetermined data is transmitted to the receiving device via wired communication.
Communication method.