Vehicle communication system, vehicle communication method, and control device

Abstract

A vehicle communication system, a vehicle communication method, and a control device are provided to reduce communication delay time between control devices that perform signal transmission and reception via the control device, and to realize a communication system with high responsiveness. The vehicle communication system includes a communication network including a plurality of communication transmission paths, and a plurality of ECUs connected by the communication network. The ECU includes a determination unit that determines a target ECU to be a communication partner, a relay transmission path via which communication with the target ECU is performed, and a relay ECU based on an input signal or input information, a waiting time decision unit that decides a transmission waiting time from when a start instruction is transmitted to another ECU closest to the relay transmission path to when a control signal for the target ECU is transmitted based on information of the relay ECU, and a communication unit that transmits the control signal after the transmission waiting time elapses after the start instruction is transmitted to the closest relay transmission path.

Description

Technical Field

[0001] This invention relates to vehicle communication systems, vehicle communication methods, and control devices. Background Technology

[0002] Previously, a communication system was disclosed in which at least one relay station exists between a master station and a slave station connected via a bus-type network (Patent Document 1). In this communication system, the slave station controls the timing of replying to the master station with response frames based on the repeater delay time, which is set based on the number of relay stations mentioned above.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-97157 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] As with the prior art described above, in a structure where the delay time is set uniformly according to the number of existing relay stations, the more relay stations there are, the more the remaining time (margin) included in the delay time increases, which may make it difficult to form a highly responsive communication system.

[0008] The purpose of this invention is to reduce the communication delay time between control devices that transmit and receive signals via a communication relay device, thereby achieving a highly responsive communication system.

[0009] This application addresses the aforementioned issues, such as improving vehicle operability, thereby contributing to the development of a sustainable transportation system that further enhances traffic safety.

[0010] Methods for solving problems

[0011] One aspect of the present invention is a vehicle communication system, which is a vehicle communication system mounted on a vehicle. The vehicle communication system includes: a communication network containing multiple communication transmission paths; and multiple ECUs connected through the communication network. Each ECU includes: a determining unit that, based on input signals or input information, determines other ECUs to be used as communication partners (i.e., target ECUs), the communication transmission path (i.e., relay transmission path) through which communication with the target ECU occurs, and other ECUs (i.e., relay ECUs); a waiting time determining unit that determines a transmission waiting time, which is the waiting time from sending a start instruction to the nearest other ECU along the relay transmission path until a control signal is sent to the target ECU; and a communication unit that, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed.

[0012] According to another aspect of the invention, the communication transmission path includes: a synchronous communication bus that initiates communication synchronously among all the connected ECUs; and an asynchronous communication bus that initiates communication asynchronously among the connected ECUs.

[0013] According to another aspect of the invention, when the nearest relay transmission path is the asynchronous communication bus, the communication unit repeatedly sends the start instruction for the nearest other ECU to the asynchronous communication bus at predetermined time intervals.

[0014] According to another aspect of the invention, when receiving a start instruction sent by another ECU as an input signal or input information, and repeatedly sending a start instruction to the asynchronous communication bus based on the input signal or input information, the communication unit causes the ECU that is the source of the received start instruction to suspend the transmission of the control signal until the transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus.

[0015] According to another aspect of the invention, the waiting time determination unit determines the transmission waiting time based on the start-up time of the other ECU closest along the relay transmission path.

[0016] Another aspect of the present invention is a vehicle communication method executed by a computer mounted on a vehicle control device, the control device being interconnected through a communication network containing multiple communication transmission paths to form a vehicle communication system, comprising the following steps: determining, based on input signals or input information, other control devices (i.e., target ECUs) to be used as communication counterparts, the communication transmission path (i.e., relay transmission path) through which communication with the target ECU takes place, and other control devices (i.e., relay ECUs); determining a transmission waiting time, the transmission waiting time being from the time a start instruction is sent to the other control device closest along the relay transmission path until a control signal is sent to the target ECU; and after the start instruction is sent to the nearest relay transmission path, transmitting the control signal after the transmission waiting time has elapsed.

[0017] Another aspect of the present invention is a control device mounted on a vehicle, wherein the control device is interconnected through a communication network including multiple communication transmission paths to form a vehicle communication system, wherein the control device comprises: a determining unit that determines, based on an input signal or input information, other control devices (i.e., target ECUs) to be used as communication counterparts, the communication transmission path (i.e., relay transmission path) through which communication with the target ECU is conducted, and other control devices (i.e., relay ECUs); a waiting time determining unit that determines a transmission waiting time, which is the waiting time from the time from sending a start instruction to the other control device closest along the relay transmission path to the time from sending a control signal toward the target ECU; and a communication unit that, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed.

[0018] Invention Effects

[0019] According to the present invention, the communication delay time between control devices that transmit and receive signals via a means of relaying communication can be reduced, thereby achieving a highly responsive communication system. Attached Figure Description

[0020] Figure 1 This is a diagram illustrating the structure of a vehicle communication system according to an embodiment of the present invention.

[0021] Figure 2 This is a diagram illustrating the first example of communication actions in a vehicle communication system.

[0022] Figure 3 This is a diagram illustrating the second example of communication actions in a vehicle communication system.

[0023] Figure 4This is a diagram showing the structure of a regional ECU, which is an example of an ECU constituting a vehicle communication system.

[0024] Figure 5 This is a flowchart illustrating the communication process that begins when communication starts in the ECU that constitutes the vehicle communication system.

[0025] Explanation of reference numerals in the attached figures

[0026] 1…Vehicle communication system, 2…Central ECU, 3…First communication line, 4…Second communication line, 29…Area ECU, 30…Lamp body, 30a…Hazard warning light, 30b…Headlight, 30c…Taillight, 30d…Directional indicator light, 30e…Brake light, 31…Window motor, 31a…Window ECU, 32…Door sensor, 33…Door lock mechanism, 33a…Door lock ECU, 34…ESL, 35…Air conditioning unit, 35a…Air conditioning ECU, 36…Entry ECU, 37…LF / RF antenna, 38…PTG-ECU, 39…Lamp body ECU, 40, 41a, 41b…Communication line, 50…Processor, 51…Memory, 52…Communication device, 53…Control unit, 54…Determination unit, 55…Waiting time determination unit, 56…Communication unit, 57…Communication network information, 58…Starting time information. Detailed Implementation

[0027] The vehicle communication system 1 of this embodiment will be described below.

[0028] Figure 1 This is a diagram showing the structure of vehicle communication system 1.

[0029] The vehicle communication system 1 includes: a communication network containing multiple communication transmission paths, and ECUs (Electronic Control Units) as multiple control devices connected through the communication network. The communication network may include multiple communication transmission paths with different communication protocols.

[0030] In this embodiment, the vehicle communication system 1 includes a central ECU 2 for overall vehicle control and information processing. The central ECU 2 is connected to communication lines including a first communication line 3 and a second communication line 4. The central ECU 2 functions as a gateway for managing the transmission and reception of communication data between these communication lines.

[0031] The first communication line 3 and the second communication line 4 are constructed from a bus that performs communication according to standards such as CAN (Controller Area Network) or Ethernet (registered trademark), or from a communication line that performs P2P (Peer-to-Peer) communication. Furthermore, the first communication line 3 can be constructed from multiple communication lines performing communication according to the same standard, or from multiple communication lines performing communication according to different standards. The same applies to the second communication line 4.

[0032] One or more other ECUs, such as a TCU (Telematics Control Unit) not shown, are connected to the first communication line 3.

[0033] A regional ECU 29 is connected to the second communication line 4. The regional ECU 29 is connected via communication line 41a to an ESL (Electronic Steering Lock) 34 and a lamp control ECU 39 that controls the illumination of the lamp body 30. Specifically, in this embodiment, the lamp body 30 includes a hazard warning light 30a, a headlight 30b, a taillight 30c, turn signals 30d, and a brake light 30e.

[0034] Additionally, the access ECU 36 is connected to the area ECU 29 via communication line 41b. The access ECU 36 is also connected to an LF / RF antenna 37 that wirelessly communicates with the vehicle's electronic key. The electronic key is an electronic device with wireless communication capabilities, also known as a smart key or FOB key. The access ECU 36 collaborates with other onboard ECUs to process user access from outside the vehicle, enabling what is known as smart entry.

[0035] Additionally, the area ECU 29 is connected via communication line 40 to the window ECU 31a, door sensor 32, PTG-ECU 38, door lock ECU 33a, and air conditioning ECU 35a. The door sensor 32 detects operations on the vehicle's doors. The window ECU 31a, door lock ECU 33a, and air conditioning ECU 35a respectively control the operation of the window motor 31 for opening and closing the windows, the door lock mechanism 33 for locking and unlocking the doors, and the air conditioning unit 35. Furthermore, the PTG-ECU 38 controls the operation of the power tailgate (power liftgate), which is not shown.

[0036] Hereinafter, the vehicle equipped with the vehicle communication system 1 will be referred to as "this vehicle", and the user using this vehicle will be referred to as "vehicle user".

[0037] Here, the central ECU2, area ECU29, entry ECU36, lamp ECU39, window ECU31a, PTG-ECU38, door lock ECU33a, and air conditioning ECU35a are equivalent to the ECUs or control devices in this disclosure.

[0038] In addition, the first communication line 3, the second communication line 4, and the communication lines 40, 41a, and 41b are equivalent to multiple communication transmission paths constituting the communication network in this disclosure.

[0039] These communication transmission paths may include communication transmission paths with different communication protocols. In this embodiment, for example, the first communication line 3 consists of multiple communication transmission paths including a communication bus containing Ethernet (registered trademark), and the second communication line 4 consists of an Ethernet communication bus. Communication lines 41a and 41b are, for example, CAN-FD communication buses that perform communication conforming to the CAN-FD communication standard. In addition, communication line 40 is, for example, a CAN communication bus that performs communication conforming to the CAN-B or CAN-C communication standards.

[0040] In this embodiment, the CAN-FD communication bus is designed for asynchronous communication, while the CAN communication bus is designed for synchronous communication. That is, communication lines 41a and 41b, which are part of the CAN-FD communication bus, correspond to the asynchronous communication bus in this disclosure that initiates communication asynchronously between connected ECUs. Conversely, communication line 40, which is part of the CAN communication bus, corresponds to the synchronous communication bus that initiates communication synchronously between all connected ECUs. In other words, the communication transmission path of the vehicle communication system 1 includes both synchronous and asynchronous communication buses.

[0041] In the vehicle communication system 1 of this embodiment, the ECU connected to the communication network determines, based on input signals or input information, other ECUs to be the communication counterpart (i.e., the target ECU), the communication transmission path (i.e., the relay transmission path) through which communication with the target ECU takes place, and other ECUs (i.e., relay ECUs). Furthermore, based on the determined relay ECUs and relay transmission path information, the ECU determines a transmission waiting time from sending a start instruction to the nearest other ECU along the relay transmission path (i.e., the nearest relay ECU, or, if there is no nearest relay ECU, the target ECU) until sending a control signal to the target ECU. After sending a start instruction to the nearest relay transmission path, and after the determined transmission waiting time has elapsed, the ECU sends the control signal.

[0042] Hereinafter, examples of two communication operations in the vehicle communication system 1 of this embodiment will be described.

[0043] The first example of a communication action is communication from PTG-ECU38 to lamp body ECU39.

[0044] Communication from PTG-ECU38 to lamp body ECU39 occurs, for example, during a so-called hazard response action, when the tailgate locking button (not shown) of this vehicle is pressed, causing the hazard warning light 30a to flash.

[0045] Figure 2 This is a diagram used to illustrate the communication actions in the first example above.

[0046] exist Figure 2 In the diagram, the horizontal axis of the topmost segment represents time; the second segment represents the status of PTG-ECU38; the third segment represents the frames or messages transmitted via communication line 40; the fourth segment represents the status of area ECU29; the fifth segment represents the frames or messages transmitted via communication line 41a; and the sixth segment represents the status of lamp body ECU39. Additionally, in... Figure 2 In this context, time is assumed to flow from left to right. Additionally, in... Figure 2 In the initial state, PTG-ECU38, area ECU29 and lamp body ECU39 are all in sleep mode.

[0047] First, the PTG-ECU38 receives a detection signal at time t0 indicating that the locking button on the tailgate has been pressed, and starts accordingly. This detection signal is equivalent to the input signal or input information in this disclosure.

[0048] In order to execute a pre-defined danger response when the start-up is completed at time t1 as a response to the pressing of the lock button, the PTG-ECU38 determines the lamp body ECU39 as the target ECU. Furthermore, the PTG-ECU38 determines communication lines 40 and 41a as relay transmission paths related to communication to the lamp body ECU39, and determines the area ECU29 as a relay ECU. The determination of these relay transmission paths and relay ECUs can be based, for example, on communication network information stored in the memory of the PTG-ECU38. When determining the relay transmission path, the PTG-ECU38 also determines whether the relay transmission path is a synchronous communication bus or an asynchronous communication bus (more specifically, a CAN communication bus or a CAN-FD communication bus). As described above, in this embodiment, communication line 40 is a CAN communication bus as a synchronous communication bus, and communication line 41a is a CAN-FD communication bus as an asynchronous communication bus.

[0049] Furthermore, the PTG-ECU38 determines the transmission waiting time from sending a start instruction to the area ECU29 to sending a control signal, based on the start time of the nearest relay ECU along the relay transmission path, i.e., the area ECU29, along communication lines 40 and 41a. The start time of the area ECU29 can be pre-stored in the PTG-ECU38.

[0050] Furthermore, after PTG-ECU38 completes startup at time t1, it begins sending a wake-up frame as a startup instruction following the CAN communication protocol to the nearest relay transmission path, namely communication line 40. This wake-up frame sent by PTG-ECU38 contains information indicating that PTG-ECU38 considers lamp body ECU39 as the communication counterpart (i.e., the target ECU).

[0051] The region ECU29, which is connected to the communication line 40 as a synchronous communication bus, typically starts up in response to receiving the initial wake-up frame and completes the start-up at time t2.

[0052] Subsequently, at time t3 after the aforementioned transmission waiting time, PTG-ECU38 sends a control signal to lamp body ECU39 to indicate the flashing of hazard warning light 30a.

[0053] Immediately after starting at time t2, the area ECU 29 designates communication line 41a as the relay transmission path related to communication with the target ECU, namely the lamp body ECU 39. Furthermore, based on the start-up time of the nearest target ECU along the relay transmission path, i.e., communication line 41a, namely the lamp body ECU 39, the area ECU 29 determines the transmission waiting time from sending the start-up instruction to the lamp body ECU 39 until the transmission of the control signal.

[0054] Furthermore, after the area ECU 29 completes startup at time t2, it sends a startup instruction conforming to the CAN-FD communication protocol to the nearest relay transmission path, namely the communication line 41a, directed towards the target ECU, namely the lamp body ECU 39. This startup instruction is sent as an NM (network management) message frame (hereinafter referred to as an NM message) conforming to the CAN-FD communication protocol. In this embodiment, in particular, since the communication line 41a is an asynchronous communication bus, the area ECU 29 repeatedly sends the NM message (hereinafter referred to as a startup NM message) as a startup instruction at predetermined time intervals. Furthermore, this time interval can be determined, for example, based on the time required for the lamp body ECU 39 to start. Alternatively, the aforementioned time interval can be predetermined.

[0055] After the start-up process is complete, the ECU29 is able to receive the control signals sent by the PTG-ECU38 at time t3.

[0056] Because of the asynchronous communication, the lamp body ECU 39, which is connected to the communication line 41a as an asynchronous communication bus, may not be able to receive the initial NM message. In this embodiment, the area ECU 29 repeatedly sends the start NM message multiple times at a predetermined time interval, so the lamp body ECU 39, as the target ECU, can reliably receive the start NM message.

[0057] exist Figure 2 In the example, the lamp body ECU 39 receives the second start NM message and begins startup, completing startup at time t4. Afterwards, at time t5, after a self-determined transmission waiting time, the area ECU 29 sends the control signal received from PTG-ECU 38 at time t3 to the lamp body ECU 39. The lamp body ECU 39, having completed startup, normally receives this control signal and begins controlling the hazard warning light.

[0058] As shown in the first example above, in this embodiment, the regional ECU 29, using communication line 41a as the nearest relay transmission path, repeatedly sends start NM messages to communication line 41a, which is an asynchronous communication bus. Therefore, in this embodiment, the target ECU, namely the lamp body ECU 39, connected to the communication line 41a, which is an asynchronous communication bus, will not experience reception errors and can reliably receive the start NM messages and begin startup. In addition, the PTG-ECU 38 and the regional ECU 29 send control signals after a transmission waiting time determined based on the startup time of the nearest communication counterpart, namely the regional ECU 29 and the lamp body ECU 39, respectively. Therefore, in this embodiment, compared with conventional communication systems that use repeater delay times set uniformly based on the number of relay stations (or relay devices) for communication, the time until the control signal sent by the ECU that initially started startup (PTG-ECU 38 in the first example) is received by the target ECU (lamp body ECU 39 in the first example) can be shortened, achieving a highly responsive communication system.

[0059] The second example of a communication action is communication from the input ECU36 to the lamp body ECU39.

[0060] Communication from the input ECU36 to the lamp body ECU39 occurs, for example, during a hazard response action that causes the hazard warning light 30a to flash when the vehicle user unlocks or locks the vehicle door using an electronic key (not shown).

[0061] Figure 3 This is a diagram used to illustrate the communication actions in the second example above.

[0062] exist Figure 3In the diagram, the horizontal axis of the topmost segment represents time; the second segment represents the state of ECU 36; the third segment represents the frames or messages transmitted via communication line 41b; the fourth segment represents the state of area ECU 29; the fifth segment represents the frames or messages transmitted via communication line 41a; and the sixth segment represents the state of lamp body ECU 39. Additionally, in... Figure 3 In this context, time is assumed to flow from left to right. Additionally, in... Figure 3 In the initial state, ECU36, ECU29, and lamp body ECU39 are all in sleep mode.

[0063] First, the ECU 36 receives a door lock or unlock command (hereinafter referred to as a lock / unlock command) from the electronic key at time t10 and starts accordingly. The lock / unlock command corresponds to the input signal or input information in this disclosure.

[0064] In order to execute a pre-defined danger response in response to a lock / unlock command when startup is completed at time t11, the entry ECU 36 determines the lamp body ECU 39 as the target ECU. Additionally, the entry ECU 36 identifies communication lines 41b and 41a as relay transmission paths related to communication to the lamp body ECU 39, and designates area ECU 29 as a relay ECU. Similar to the first example, the determination of these relay transmission paths and relay ECUs can be based, for example, on communication network information stored in the memory of the entry ECU 36. When determining a relay transmission path, the entry ECU 36 also determines whether the relay transmission path is a synchronous communication bus or an asynchronous communication bus.

[0065] Furthermore, the ECU36 determines the transmission waiting time from sending a start instruction to the regional ECU29 to sending a control signal, based on the start time of the nearest ECU, namely the regional ECU29, along communication lines 41b and 41a, which serve as relay transmission paths. The start time of the regional ECU29 can be pre-stored in the ECU36.

[0066] Then, after the ECU 36 completes startup at time t11, it begins sending a Start NM message as a startup instruction following the CAN-FD communication protocol to the nearest relay transmission path, i.e., communication line 41b. Similar to the first example described above, in this embodiment, especially since communication line 41b is an asynchronous communication bus, the ECU 36 repeatedly sends the Start NM message at predetermined time intervals. Assume that this Start NM message contains information indicating that the ECU 36 considers the lamp body ECU 39 as a communication counterpart (i.e., the target ECU).

[0067] Regarding communication line 41a, as described above, the regional ECU 29, connected to communication line 41b (which is an asynchronous communication bus), may not be able to receive the initial NM message due to asynchronous communication. In this embodiment, the entry ECU 36 repeatedly sends the start NM message, thus the regional ECU 29 can reliably receive the start NM message.

[0068] exist Figure 3 In the example, the regional ECU 29 receives the second start NM message and begins startup, completing startup at time t12. Then, the entry ECU 36 sends a control signal to the lamp body ECU 39 to indicate the flashing of the hazard warning light 30a at time t13 after its own determined transmission waiting time.

[0069] Immediately after starting at time t12, the area ECU 29 designates communication line 41a as the relay transmission path related to communication with the target ECU, namely the lamp body ECU 39. Furthermore, based on the start-up time of the nearest target ECU along the relay transmission path, i.e., communication line 41a, namely the lamp body ECU 39, the area ECU 29 determines the transmission waiting time from sending the start-up instruction to the lamp body ECU 39 until the transmission of the control signal.

[0070] Furthermore, similar to the first example above, after the start-up is completed at time t12, the area ECU29, facing the target ECU, i.e. the lamp body ECU39, repeatedly sends start-up NM messages as start-up instructions following the CAN-FD communication protocol to the nearest relay transmission path, i.e., the communication line 41a, at a predetermined time interval.

[0071] After the start-up process is complete, ECU29 is able to receive the control signals sent by ECU36 at time t13.

[0072] The lamp ECU 39, for example, receives a second start NM message and begins startup, completing startup at time t14. Afterwards, at time t15, the area ECU 29 sends the control signal received from the input ECU 36 at time t13 to the lamp ECU 39 after its own predetermined transmission waiting time. The lamp ECU 39, having completed startup, normally receives this control signal and begins controlling the hazard warning light.

[0073] Similar to the first example described above, in the second example, the entry ECU 36, which uses communication line 41b as the nearest relay transmission path, and the area ECU 29, which uses communication line 41a as the nearest relay transmission path, repeatedly send start NM messages to communication lines 41b and 41a, which are asynchronous communication buses. Therefore, in this embodiment, the area ECU 29 connected to communication line 41b and the lamp body ECU 39 connected to communication line 41a will not experience reception errors and can reliably receive the start NM message to begin starting.

[0074] Furthermore, both the entry ECU 36 and the area ECU 29 send control signals after a transmission waiting time predetermined based on the start-up time of their nearest communication counterparts, namely the area ECU 29 and the lamp body ECU 39. Therefore, in this embodiment, compared to conventional communication systems that use the same set repeater delay time for communication, the time until the control signal sent by the initially started ECU (entry ECU 36 in the second example) is received by the target ECU (lamp body ECU 39 in the second example) can be shortened, achieving a highly responsive communication system.

[0075] Next, the structure of the ECU will be explained.

[0076] Figure 4 A diagram showing the structure of region ECU29, which is an example of an ECU.

[0077] The regional ECU 29 includes a processor 50, a memory 51, and a communication device 52. The memory 51 is constructed, for example, of a volatile and / or non-volatile semiconductor memory. Information regarding... is pre-stored in the memory 51. Figure 1 The information in the vehicle communication system 1 shown, including ECUs and other vehicle-mounted devices, and the communication transmission paths connecting these devices, is called communication network information 57. Additionally, the memory 51 stores pre-stored information about the start-up times of the ECUs and other vehicle-mounted devices in the vehicle communication system 1, namely, start-up time information 58.

[0078] Communication device 52 is a transceiver used to communicate with other ECUs via a communication network.

[0079] The communication device 52 includes, for example, a CAN transceiver that communicates via a communication line 40, which is a CAN communication bus that is a synchronous communication bus, and a CAN-FD transceiver that communicates via a second communication line 4 and communication lines 41a and 41b, which are CAN-FD communication buses that are asynchronous communication buses.

[0080] The processor 50 is, for example, a computer equipped with a CPU. The processor 50 includes a control unit 53, a determination unit 54, a latency determination unit 55, and a communication unit 56 as functional elements or units. These functional elements can be implemented by the processor 50, which is a computer, executing a program. Furthermore, the aforementioned computer program can be stored in any storage medium readable by a computer. Alternatively, all or part of the aforementioned functional elements of the processor 50 can be constituted by hardware comprising one or more electronic circuit components.

[0081] The control unit 53 performs predetermined control actions as actions to be performed by the ECU (regional ECU 29 in this example). In the regional ECU 29, the control actions performed by the control unit 53 may include, for example, a communication relay action that controls the communication flow between different communication lines connected to the communication device 52.

[0082] The determination unit 54 determines other ECUs, i.e., target ECUs, that are to be communicated with in connection with the aforementioned control action, based on input signals or input information received via the communication device 52 or directly received from other sensors, devices, etc. (not shown). Furthermore, the determination unit 54 refers to communication network information stored in the memory 51 to determine relay transmission paths that serve as the communication transmission path to the determined target ECU and relay ECUs that serve as other ECUs.

[0083] The waiting time determination unit 55 determines the transmission waiting time from sending a start instruction to the nearest other ECU along the relay transmission path (i.e., the nearest relay ECU, or the target ECU if there is no nearest relay ECU, hereinafter the same) to sending a control signal to the target ECU, based on the information of the relay ECU and the relay transmission path determined by the determination unit 54. The waiting time determination unit 55 determines the transmission waiting time, for example, by referring to the start time information stored in the memory 51 and based on the start time of the nearest other ECU along the relay transmission path. Alternatively, the transmission waiting time may be set to the same predetermined time regardless of the relay transmission path or the target ECU.

[0084] The communication unit 56 sends a start instruction to the nearest relay transmission path, indicating that the nearest other ECU has started. Furthermore, after initiating the transmission of the start instruction, the communication unit 56 sends a control signal to the target ECU after the transmission waiting time has elapsed since the start of the start instruction. Therefore, in this embodiment, the control signal is sent after the nearest other ECU has completed starting, thus ensuring reliable reception of the transmitted control signal in the nearest other ECU. Additionally, since the transmission waiting time is based on the start time of the nearest other ECU, the vehicle communication system 1 of this embodiment improves the responsiveness of the communication system, such as the responsiveness of coordinated operations between ECUs, compared to conventional communication systems that use delay times that are uniformly determined based on the number of relay devices.

[0085] Furthermore, when the nearest relay transmission path is an asynchronous communication bus, the communication unit 56, upon receiving an input signal or input information, repeatedly sends start instructions for the nearest other ECU to the asynchronous communication bus, which serves as the relay transmission path, at predetermined time intervals. Therefore, the start instructions can be reliably received by the nearest other ECU connected to the asynchronous communication bus, which serves as the relay transmission path.

[0086] Additionally, when the communication unit 56 receives a start instruction from another ECU as an input signal or input information, and repeatedly sends start instructions to the asynchronous communication bus based on that input signal or input information, it may instruct the ECU that is the source of the received start instruction to temporarily suspend the transmission of control signals until a transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus. This instruction can, for example, be set by the communication unit 56 to send it to the other ECU via the communication transmission path that sent the start instruction as an input signal or input signal. Alternatively, if the communication transmission path with the other ECU that sent the start instruction as an input signal or input signal can be set to a busy state, the communication unit 56 can give this instruction by setting the communication transmission path to a busy state.

[0087] Furthermore, as mentioned above, Figure 4 The area ECU29 shown is one example of an ECU; other ECUs can also have similar characteristics. Figure 4 The area ECU 29 shown has the same structure. In this case, the control unit 53 is configured to perform control actions corresponding to the control functions provided to each ECU. In addition, the determination unit 54 can determine the target ECU that is associated with the control action and is to be used as a communication partner based on the input signals or input information determined according to the control functions.

[0088] Next, the process of communication operation performed by the on-board ECU (control device) constituting the vehicle communication system 1 of the present invention at the start of communication with other ECUs will be described. Figure 5 This is a flowchart illustrating the process of the aforementioned communication action. This communication action is performed, for example, by region ECU29, which is an example of an ECU. Figure 5 In the communication action, the ECU associated with the communication action is set to include region ECU29, which is in a sleep state where control actions have been stopped.

[0089] When processing begins, the determination unit 54 determines whether an input signal or input information has been received in the sleep state (S100). The input signal or input information can be received from other ECUs and / or on-board devices such as sensors. Furthermore, if no input signal or input information is received (S100 is "No"), the determination unit 54 returns to step S100 and repeatedly performs processing, waiting to receive an input signal or input information.

[0090] On the other hand, upon receiving an input signal or input information (S100 is "Yes"), the determining unit 54 determines the target ECU, the relay transmission path to be traversed for communication with the target ECU, and the relay ECU based on the received input signal or input information (S102). As described above, the target ECU refers to another ECU that the communication unit 56 intends to use as a communication partner. Furthermore, the relay transmission path refers to the communication transmission path traversed for communication with the target ECU, and the relay ECU refers to another ECU traversed for communication with the target ECU.

[0091] Next, the waiting time determination unit 55 determines the transmission waiting time based on the information of the relay ECU and the relay transmission path determined above (S104). As described above, the transmission waiting time refers to the waiting time from the time the start instruction is sent to the other ECU closest along the relay transmission path until the control signal to the target ECU is sent. In this embodiment, the transmission waiting time specifically refers to the waiting time from the time the start instruction is sent until the control signal is sent.

[0092] Next, after sending a start instruction to the nearest communication transmission path along the relay transmission path (S106), the communication unit 56 determines whether the transmission waiting time determined above has elapsed since the start of sending the start instruction (S108). If the transmission waiting time has not elapsed (S108 is "No"), the communication unit 56 returns to step S108 and repeats the process, waiting for the transmission waiting time to elapse.

[0093] On the other hand, after the transmission waiting time has elapsed (S108 is "Yes"), the communication unit 56 sends a signal related to the control action of the target ECU, namely a control signal (S110), and ends the processing.

[0094] [Other Implementation Methods]

[0095] In the above embodiment, the transmission waiting time determined by the waiting time determination unit 55 is the waiting time from the start of transmitting the start instruction to the transmission of the control signal, but it is not limited to this. For example, in the case of repeatedly transmitting the start signal, the transmission waiting time can be set to the waiting time from the end of the transmission of the last start signal.

[0096] Furthermore, the present invention is not limited to the structure of the embodiments described above, and can be implemented in various ways without departing from its spirit.

[0097] For example, in the above embodiments, CAN bus and CAN-FD bus are exemplified as synchronous communication buses and asynchronous communication buses, but synchronous communication buses and asynchronous communication buses are not limited to these.

[0098] [Structure supported by the above embodiments]

[0099] The above implementation supports the following structure.

[0100] (Structure 1) A vehicle communication system, which is mounted on a vehicle, the vehicle communication system comprising: a communication network including multiple communication transmission paths; and multiple ECUs connected through the communication network, wherein each ECU comprises: a determining unit that determines, based on an input signal or input information, other ECUs to be used as communication counterparties (i.e., target ECUs), the communication transmission path through which communication with the target ECU is traversed (i.e., relay transmission path), and other ECUs (i.e., relay ECUs); a waiting time determining unit that determines a transmission waiting time, the transmission waiting time being from the time when a start instruction is sent to the other ECU closest along the relay transmission path until a control signal is sent to the target ECU; and a communication unit that, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed.

[0101] According to the vehicle communication system of Structure 1, even when communication is carried out via multiple ECUs, each ECU uses information from the nearest other ECU along the relay transmission path to determine the transmission waiting time. Therefore, the communication delay time from the ECU that is the communication source to the target ECU can be reduced, and a highly responsive vehicle communication system can be achieved.

[0102] (Structure 2) The vehicle communication system of Structure 1, wherein the communication transmission path includes: a synchronous communication bus, which initiates communication synchronously among all the connected ECUs; and an asynchronous communication bus, which initiates communication asynchronously among the connected ECUs.

[0103] According to the vehicle communication system of Structure 2, a highly responsive vehicle communication system can be achieved even when multiple communication transmission paths with different communication protocols are included.

[0104] (Structure 3) In the vehicle communication system of Structure 2, when the nearest relay transmission path is the asynchronous communication bus, the communication unit repeatedly sends the start instruction for the nearest other ECU to the asynchronous communication bus at a predetermined time interval.

[0105] According to the vehicle communication system of Structure 3, the start instruction can also be reliably received by the ECU connected via the asynchronous communication bus.

[0106] (Structure 4) The vehicle communication system of Structure 3, wherein when receiving a start instruction sent by another ECU as an input signal or input information, and repeatedly sending a start instruction to the asynchronous communication bus based on the input signal or input information, the communication unit causes the ECU that is the source of the received start instruction to suspend the transmission of the control signal until the transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus.

[0107] According to the vehicle communication system of Structure 4, the ECU that has started communication can send control signals in a manner that matches the timing of the target ECU's start-up completion, thus facilitating coordinated actions between ECUs.

[0108] (Structure 5) A vehicle communication system of any one of Structures 1 to 4, wherein the waiting time determination unit determines the transmission waiting time based on the start time of the other ECU closest along the relay transmission path.

[0109] According to the vehicle communication system of Structure 5, the transmission waiting time is determined in accordance with the start-up time of the other ECUs closest along the relay transmission path. Therefore, even when communication is carried out via multiple ECUs, the communication delay time from the ECU that is the communication source to the target ECU can be easily reduced, resulting in a more responsive vehicle communication system.

[0110] (Structure 6) A vehicle communication method executed by a computer mounted on a control device of a vehicle, the control device being interconnected through a communication network containing multiple communication transmission paths to form a vehicle communication system, wherein the vehicle communication method comprises the following steps: determining, based on an input signal or input information, other control devices to be used as communication counterparties, i.e., target ECUs, the communication transmission path via which communication with the target ECU is conducted, i.e., a relay transmission path, and other control devices, i.e., relay ECUs; determining a transmission waiting time, the transmission waiting time being from sending a start instruction to the other control device closest along the relay transmission path to sending a control signal to the target ECU; and after sending the start instruction to the nearest relay transmission path, sending the control signal after the transmission waiting time has elapsed.

[0111] According to the vehicle communication method of Structure 6, even when communication is carried out via multiple ECUs, each ECU uses information from the nearest other ECU along the relay transmission path to determine the transmission waiting time. Therefore, the communication delay time from the ECU that is the communication source to the target ECU can be reduced, and a highly responsive vehicle communication system can be achieved.

[0112] (Structure 7) A control device mounted on a vehicle, the control device being interconnected via a communication network including multiple communication transmission paths to form a vehicle communication system, wherein the control device comprises: a determining unit that determines, based on an input signal or input information, other control devices to be used as communication counterparties, i.e., a target ECU, the communication transmission path through which communication with the target ECU is traversed, i.e., a relay transmission path, and other control devices, i.e., relay ECUs; a waiting time determining unit that determines a transmission waiting time, the transmission waiting time being the waiting time from sending a start instruction to the other control device closest along the relay transmission path until a control signal is sent to the target ECU; and a communication unit that, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed.

[0113] According to the control device of structure 7, a highly responsive vehicle communication system can be constructed.

Claims

1. A vehicle communication system, which is mounted on a vehicle, the vehicle communication system comprising: a communication network including multiple communication transmission paths; and multiple ECUs connected through the communication network, wherein, The ECU has: The determining unit, based on input signals or input information, determines the other ECUs to be used as communication counterparties, i.e., the target ECU, the communication transmission path through which communication with the target ECU is conducted, i.e., the relay transmission path, and the other ECUs, i.e., the relay ECUs. The waiting time determination unit determines the transmission waiting time, which is the waiting time from the time a start instruction is sent to the other ECU closest along the relay transmission path until the control signal to the target ECU is sent; as well as The communication unit, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed. The communication transmission path includes: A synchronous communication bus that initiates communication synchronously among all the connected ECUs; as well as An asynchronous communication bus, which initiates communication asynchronously between the connected ECUs. When the nearest relay transmission path is the asynchronous communication bus, the communication unit repeatedly sends the start instruction for the nearest other ECU to the asynchronous communication bus at predetermined time intervals. When receiving a start instruction from another ECU as an input signal or input information, and repeatedly sending a start instruction to the asynchronous communication bus based on the input signal or input information, the communication unit causes the ECU that is the source of the received start instruction to suspend the transmission of the control signal until the transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus.

2. The vehicle communication system according to claim 1, wherein, The waiting time determination unit determines the transmission waiting time based on the start-up time of the other ECU closest to the relay transmission path.

3. A vehicle communication method, which is a vehicle communication method executed by a computer mounted on a control device of a vehicle, wherein the control device is interconnected through a communication network containing multiple communication transmission paths to form a vehicle communication system, wherein... The vehicle communication method includes the following steps: Based on input signals or input information, determine the other control devices to be used as communication counterparties, i.e., the target ECU, the communication transmission path through which communication with the target ECU is conducted, i.e., the relay transmission path, and the other control devices, i.e., the relay ECU; The transmission waiting time is determined, which is the waiting time from the time a start instruction is sent to the nearest other control device along the relay transmission path until the control signal towards the target ECU is sent; and After sending the start instruction to the nearest relay transmission path, the control signal is sent after the transmission waiting time has elapsed. The communication transmission path includes: A synchronous communication bus that initiates communication synchronously among all the connected control devices; and An asynchronous communication bus, which initiates communication asynchronously between the connected control devices. In the sending step, When the nearest relay transmission path is the asynchronous communication bus, the start instruction for the nearest other control device is repeatedly sent to the asynchronous communication bus at predetermined time intervals. When receiving a start instruction from another control device as an input signal or input information, and repeatedly sending a start instruction to the asynchronous communication bus based on the input signal or input information, the control device that is the source of the received start instruction shall suspend the transmission of the control signal until the transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus.

4. A control device mounted on a vehicle, wherein the control device is interconnected via a communication network containing multiple communication transmission paths to form a vehicle communication system, wherein... The control device includes: The determining unit, based on input signals or input information, determines the other control device to be the communication counterparty, i.e., the target ECU, the communication transmission path through which the communication with the target ECU is conducted, i.e., the relay transmission path, and the other control devices, i.e., the relay ECU. The waiting time determination unit determines the transmission waiting time, which is the waiting time from the time a start instruction is sent to the other control device closest along the relay transmission path until the control signal to the target ECU is sent. as well as The communication unit, after sending the start instruction to the nearest relay transmission path, sends the control signal after the transmission waiting time has elapsed. The communication transmission path includes: A synchronous communication bus that initiates communication synchronously among all the connected control devices; as well as An asynchronous communication bus, which initiates communication asynchronously between the connected control devices. When the nearest relay transmission path is the asynchronous communication bus, the communication unit repeatedly sends start instructions for the nearest other control device to the asynchronous communication bus at predetermined time intervals. When receiving a start instruction from another control device as an input signal or input information, and repeatedly sending a start instruction to the asynchronous communication bus based on the input signal or input information, the communication unit causes the control device, which is the source of the received start instruction, to suspend the transmission of the control signal until the transmission waiting time has elapsed since the start instruction was sent to the asynchronous communication bus.

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