Communication system

Abstract

In a communication system where multiple communication devices are connected to form a hierarchical structure, this technology provides a way to suppress the increase in the time it takes for multiple communication devices to wake up sequentially at each hierarchical level. [Solution] In S102, the transfer unit determines the transmission bus. In S103, the transfer unit transmits a wake-up signal while remaining in sleep mode. Also, in S104, the activation unit transitions the first communication device and / or one or more second communication devices from sleep mode to wake-up mode.

Description

Technical Field

[0001] The present disclosure relates to a communication system.

Background Art

[0002] Patent Document 1 below describes a communication system configured such that a plurality of communication devices communicate via a communication line. Each communication device has a wake-up mode and a sleep mode as operation modes. In Patent Document 1, the wake-up mode is a normal operation mode capable of executing all functions assigned in advance. The sleep mode is an operation mode in which some functions are stopped to suppress power consumption.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, a plurality of communication devices may be connected so as to form a hierarchical structure. As a result of the inventor's detailed examination in such a communication system, the following problems have been found. That is, when each communication device transitions from the sleep mode to the wake-up mode, when a plurality of communication devices are connected so as to form a hierarchical structure, it is necessary to gradually transition each communication device to the wake-up mode for each layer. In this case, a lot of time is required from when the communication device belonging to the first layer transitions to the wake-up mode until the communication device belonging to the last layer transitions to the wake-up mode.

[0005] One aspect of this disclosure is to provide a technology that suppresses the increase in time required when multiple communication devices are sequentially woken up layer by layer in a communication system in which multiple communication devices are connected to form a hierarchical structure. [Means for solving the problem]

[0006] One aspect of the present disclosure is a communication system (100, 200, 300). The communication system comprises a first communication device (1, 204), one or more second communication devices (2-4, 202, 203, 205), and one or more third communication devices (5a-5x). One or more second communication devices are connected to communication lines (6a-6c, 201) so as to enable direct communication with the first communication device. One or more third communication devices are connected to communication lines (6d-6k) so as to enable direct communication with either the first communication device or one or more second communication devices. The first communication device, one or more second communication devices, and one or more third communication devices each comprise, in order, a first transceiver (15-17, 315), a second transceiver (23-25, 323), and a third transceiver (54). The first communication device, one or more second communication devices, and one or more third communication devices have a wake-up state and a sleep state. The wake-up state is the normal operating state. The sleep state is a low-power operating state in which some or all functions other than those provided by each transceiver are restricted. The first transceiver, the second transceiver, and the third transceiver each include a detection unit (15a, 23a, 54a) and an activation unit (15b, 23b, 54b). The detection unit is configured to detect a wake-up signal, which is a signal that instructs the device to transition to the wake-up state. The activation unit is configured to transition its communication device from the sleep state to the wake-up state when the wake-up signal is detected by the detection unit. The first transceiver and / or the second transceiver include a transfer unit (15c, 23c) configured to transmit the wake-up signal to a different communication line from the one on which the wake-up signal was detected, while remaining in the sleep state, when the wake-up signal is detected by the detection unit.

[0007] With this configuration, in a communication system where multiple communication devices are connected to form a hierarchical structure, it is possible to suppress the increase in the time it takes for multiple communication devices to wake up sequentially at each hierarchical level. For example, when transitioning to the wake-up state sequentially from the hierarchical level to which the first communication device belongs, to the hierarchical level to which one or more second communication devices belong, and to the hierarchical level to which one or more third communication devices belong, it is possible to suppress the increase in the time it takes to wake up compared to a communication system without a transfer unit. That is, the second communication device can transmit a wake-up signal to the third communication device while remaining in sleep mode. In other words, while the second communication device is transitioning to the wake-up state, the third communication device is also transitioning to the wake-up state. Therefore, the time it takes for all nodes at all levels to transition to the wake-up state can be shortened. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing the first and second layers of the communication system configuration. [Figure 2] This is a block diagram showing the third layer of the communication system configuration. [Figure 3] This is a flowchart of the wake-up preprocessing. [Figure 4] This is a schematic diagram showing the configuration of the communication system in the modified example 1. [Figure 5] This is a block diagram showing the first and second layers of the communication system configuration in Modification Example 2. [Modes for carrying out the invention]

[0009] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Embodiments] [1-1. Structure] The communication system 100 shown in Figures 1 and 2 constitutes an in-vehicle network system installed in a vehicle such as a passenger car. The communication system 100 comprises a central ECU 1, multiple zone ECUs 2 to 4, and multiple terminal ECUs 5a to 5r. ECU stands for Electronic Control Unit. Hereinafter, the central ECU 1, the multiple zone ECUs 2 to 4, and the multiple terminal ECUs 5a to 5r may also be referred to as nodes.

[0010] A node is a communication device equipped with communication capabilities. The central ECU1 integrates multiple zone ECUs 2-4 to achieve coordinated control of the entire vehicle. The central ECU1 is connected to communication lines 6a-6c so that it can communicate directly with the multiple zone ECUs 2-4. Direct communication means that data can be sent and received without the need for relay devices. The central ECU1 is connected to the multiple zone ECUs 2-4 via individual communication lines 6a-6c. The central ECU1 and the multiple zone ECUs 2-4 are connected via a first network. The first network is, for example, Ethernet. Ethernet is a registered trademark.

[0011] Zone ECUs 2-4 are provided for each zone that divides the area where the communication system 100 is installed. More specifically, Zone ECUs 2-4 are provided for each zone that divides the area within the vehicle, and primarily control multiple terminal ECUs 5a-5r located within that zone. Each Zone ECU 2-4 is connected to multiple terminal ECUs 5a-5r located within its zone via separate communication lines 6d-6i. In other words, multiple terminal ECUs 5a-5r are connected to communication lines 6d-6i so that they can communicate directly with any of the multiple Zone ECUs 2-4. Furthermore, terminal ECUs 5a-5r connected to different communication lines can communicate indirectly with each other. Indirect communication means that frames can be sent and received via at least one relay device. Here, the central ECU 1 and the multiple Zone ECUs 2-4 also function as relay devices for relaying frames. For example, terminal ECU 5a connected to communication line 6d and terminal ECU 5d connected to communication line 6e can transmit and receive frames via zone ECU 2 acting as a relay device. Also, for example, terminal ECU 5g connected to communication line 6f and terminal ECU 5p connected to communication line 6i can transmit and receive frames via zone ECU 3, central ECU 1, and zone ECU 4 acting as relay devices.

[0012] Each zone ECU2-4 and its subordinate terminal ECUs 5a-5r are connected via a second network. This second network uses technologies such as CAN. CAN stands for Controller Area Network.

[0013] Furthermore, the first and second networks may be any network utilizing any communication protocol, not limited to Ethernet or CAN. Any communication protocol may include LIN, FlexRay®, MOST®, and CXPI®. LIN stands for "Local Interconnect Network." MOST stands for "Media Oriented Systems Transport." CXPI stands for "Clock Extension Peripheral Interface."

[0014] As described above, in the communication system 100, the nodes are connected in a hierarchical structure. The hierarchical layer to which the central ECU 1 belongs is called the first hierarchical layer, the hierarchical layer to which the multiple zone ECUs 2 to 4 belong is called the second hierarchical layer, and the hierarchical layer to which the multiple terminal ECUs 5a to 5r belong is called the third hierarchical layer.

[0015] A node can transition between a wake-up state and a sleep state. The wake-up state is the normal operating state in which all functions assigned to the node are available. The sleep state is a low-power operating state in which at least some functions are limited. More specifically, the sleep state is a low-power operating state in which some or all functions other than those provided by the node's transceiver are limited.

[0016] The central ECU1 and the multiple zone ECUs 2-4 have a wake-up pre-emptive function. The wake-up pre-emptive function is a function that sends a signal to wake up other nodes when the node itself is in a sleep state. In other words, when the node receives a signal instructing it to transition to a wake-up state, it sends a signal to wake up other nodes before the node itself transitions from sleep state to wake-up state. The wake-up pre-emptive function is executed when the central ECU1 and the multiple zone ECUs 2-4 act as relay devices and relay NM frames, which will be described later.

[0017] [1-1-1. Central ECU] The central ECU 1 includes an MPU 11, an MCU 12, a wireless communication unit 14, and first transceivers 15 to 17. MPU is the abbreviation of Micro Processing Unit. MCU is the abbreviation of Micro Control Unit. The sleep state of the central ECU 1 includes a state where the power supply to the MPU 11 and the MCU 12 is cut off, and a state where the power supply to the MPU 11 and the MCU 12 is started but the transition to the wake-up state has not been completed (in other words, the state during the transition to the wake-up state). Even in the sleep state, the functions provided by the first transceivers 15 to 17 and the functions provided by the wireless communication unit 14 can be used.

[0018] The MPU 11 and the MCU 12 include a CPU and a semiconductor memory (hereinafter referred to as a memory) such as a ROM or a RAM. A program for the CPU to execute a predetermined function is stored in the memory.

[0019] The central ECU 1 realizes the function as the NM control unit 13 by the CPU executing the program in the memory. The NM control unit 13 is configured to generate an NM frame. The NM frame is a frame for managing the state of the communication system 100. For example, the NM frame includes a first frame indicating that the transceiver of the own node is available and a second frame instructing other nodes to transition to the wake-up state.

[0020] In this embodiment, the nodes constituting the communication system 100 are pre-classified into a plurality of groups. Each group belongs to one or more nodes necessary to realize one service. For example, the group to which the nodes necessary to realize the service of the car finder described later belong is the first group, the group to which the nodes necessary to realize the monitoring service described later belong is the second group, and the group to which the nodes necessary to realize the key service described later belong is the third group. Alternatively, a plurality of groups to which one or more nodes belong may be set in advance, and one or more groups corresponding to each service may be defined. Here, the service may be a specific function or a general term for a group of services such as during parking or driving.

[0021] The second frame is generated by associating the position of the bits in the data field with the group. For example, the upper first bit of the data field is assigned to the first group, and rules are set in advance such that if the upper first bit of the data field is "1", the nodes belonging to the first group transition to the wake-up state.

[0022] The NM control unit 13 generates the second frame according to pre-determined rules. Each node determines whether to wake up when receiving the second frame according to pre-determined rules. To realize each service, the nodes belonging to each group need to be awake, and each node transitions to the wake-up state according to such rules.

[0023] The wireless communication unit 14 is a transceiver configured to enable wireless communication with a communication device outside the vehicle. For example, the wireless communication unit 14 is configured to be able to receive events from the cloud.

[0024] The first transceiver 15 is connected to the second transceiver 23 of the zone ECU 2 via the communication line 6a. The first transceiver 16 is connected to the second transceiver 23 of zone ECU 3 via communication line 6b. The first transceiver 17 is connected to the second transceiver 23 of zone ECU 4 via communication line 6c.

[0025] The first transceivers 15-17 are configured to process NM frames. Processing NM frames means having the function of receiving NM frames and reading data. The first transceivers 15-17 include a detection unit 15a, an activation unit 15b, and a transfer unit 15c. Each function of the first transceivers 15-17 is implemented by hardware circuits. A circuit refers to one or more logic circuits as hardware, configured to perform specific processing defined based on a pre-designed circuit configuration. In other words, a circuit refers to a hardware device that performs specific processing based on a circuit configuration, rather than processing defined by software such as computer program code. For example, a circuit may include custom ICs such as ASICs and FPGAs designed using hardware description languages. That is, a circuit includes all hardware circuits except for processors that execute processing by reading computer program code. ASIC stands for "Application Specific Integrated Circuit." FPGA stands for "Field Programmable Gate Array."

[0026] The detection unit 15a is configured to detect a wake-up signal. The wake-up signal is a signal that instructs a node to transition to the wake-up state. In this embodiment, an NM frame generated by another node is used as the wake-up signal. More specifically, a second frame generated by another node is used as the wake-up signal.

[0027] For example, the detection unit 15a may detect a wake-up signal if the bit position in the data field corresponding to the group to which its node belongs is "1". The startup unit 15b is configured to transition its node from sleep state to wake-up state when a wake-up signal is detected by the detection unit 15a. More specifically, when a wake-up signal is detected by the detection unit 15a, the startup unit 15b controls the resumption of power supply to the MPU 11 and MCU 12.

[0028] The transfer unit 15c is configured to transmit a wake-up signal to a different communication line than the one on which the wake-up signal was detected, while remaining in sleep mode, when the wake-up signal is detected by the detection unit 15a. In other words, the transfer unit 15c simply transfers the second frame that the detection unit 15a has detected as a wake-up signal.

[0029] More specifically, the transfer unit 15c is configured to transmit the wake-up signal to a predetermined communication line depending on the communication line that received the wake-up signal. Specifically, a receiving bus, which is the communication line that receives the wake-up signal, and a transmitting bus, which is the communication line that transmits the wake-up signal, are pre-associated and set up. The transfer unit 15c transfers the wake-up signal according to the pre-associated correspondence. For example, if the receiving bus is communication line 6a, the transmitting bus is set to communication line 6c, and if the receiving bus is communication line 6b, the transmitting bus is set to communication line 6a and communication line 6c, and so on. The process by which the transfer unit 15c determines which communication line to transfer the wake-up signal to and transfers the wake-up signal is also called routing processing.

[0030] When the detection unit 15a detects a wake-up signal, the activation unit 15b performs the transition to the wake-up state, and the transfer unit 15c transfers the wake-up signal. In other words, when the detection unit 15a detects a wake-up signal, the first transceivers 15-17 perform the process of restarting power to the MPU 11 and MCU 12 and the process of transferring the wake-up signal almost simultaneously. When power is restarted, the MPU 11 and MCU 12 perform the necessary processes to transition to the wake-up state, such as executing an initial sequence. Therefore, it takes time for the MPU 11 and MCU 12 from the start of power supply until the transition to the wake-up state is completed. On the other hand, the processing of the transfer unit 15c is implemented by hardware circuitry and only transfers the wake-up signal to a predetermined communication line, so it does not take much time. Therefore, even if the processes of the startup unit 15b and the transfer unit 15c are executed simultaneously, the result is that the wake-up signal is transferred by the transfer unit 15c before the transition to the wake-up state, which is performed by the startup unit 15b, is completed.

[0031] [1-1-2. Zone ECU] Zones ECU2 to 4 are equipped with an MCU21 and second transceivers 23 to 25. The sleep state in zones ECU2 to 4 includes a state in which power to the MCU21 is cut off, and a state in which power to the MCU21 has been restored but the transition to the wake-up state has not yet been completed (in other words, a state in the process of transitioning to the wake-up state). Even in the sleep state, the functions of the second transceivers 23 to 25 are available.

[0032] The MCU21 comprises a CPU and memory. The memory stores programs that allow the CPU to perform predetermined functions. Zone ECUs 2-4 function as NM control units 22 by having the CPU execute programs stored in memory. The NM control units 22 are configured to generate NM frames, similar to the NM control unit 13 of the central ECU 1.

[0033] The second transceiver 23 of Zone ECU2 is connected to the first transceiver 15 of Central ECU1 via communication line 6a. The second transceiver 24 of zone ECU2 is connected to the third transceiver 54 of terminal ECUs 5a, 5b, and 5c via communication line 6d.

[0034] The second transceiver 25 of zone ECU2 is connected to the third transceiver 54 of terminal ECUs 5d, 5e, and 5f via communication line 6e. The second transceiver 23 of Zone ECU3 is connected to the first transceiver 16 of Central ECU1 via communication line 6b.

[0035] The second transceiver 24 of zone ECU3 is connected to the third transceiver 54 of terminal ECUs 5g, 5h, and 5i via communication line 6f. The second transceiver 25 of zone ECU3 is connected to the third transceiver 54 of terminal ECUs 5j, 5k, and 5l via communication line 6g.

[0036] The second transceiver 23 of Zone ECU 4 is connected to the first transceiver 17 of Central ECU 1 via communication line 6c. The second transceiver 24 of zone ECU4 is connected to the third transceiver 54 of terminal ECUs 5m, 5n, and 5o via communication line 6h.

[0037] The second transceiver 25 of zone ECU4 is connected to the third transceiver 54 of terminal ECUs 5p, 5q, and 5r via communication line 6i. The second transceivers 23-25 ​​are configured to process NM frames. Each of the second transceivers 23-25 ​​includes a detection unit 23a, an activation unit 23b, and a transfer unit 23c. The functions of the second transceivers 23-25 ​​are implemented by hardware circuits, similar to the first transceivers 15-17.

[0038] Each detection unit 23a is configured to detect a wake-up signal. Each startup unit 23b is configured to transition its node from sleep state to wake-up state when a wake-up signal is detected by each detection unit 23a. More specifically, each startup unit 23b controls the power supply to the MCU 21 to be resumed when a wake-up signal is detected by each detection unit 23a.

[0039] Each transfer unit 23c is configured to transmit a wake-up signal to a different communication line from the one on which the wake-up signal was detected, while remaining in sleep mode, when a wake-up signal is detected by each detection unit 23a. Each transfer unit 23c is configured to have a pre-associated receiving bus and transmitting bus, for example, if the receiving bus is communication line 6a, the transmitting bus is communication line 6d and communication line 6e, and if the receiving bus is communication line 6e, the transmitting bus is communication line 6d.

[0040] Furthermore, each transfer unit 23c also performs protocol conversion processing, which involves converting Ethernet frames to CAN frames and CAN frames to Ethernet frames. Even when an NM frame detected by the detection unit 23a is protocol-converted and transferred by the transfer unit 23c, the detected NM frame and the transferred NM frame may be treated as the same frame. In other words, the wake-up signal transmitted by the transfer unit 23c may be considered identical to the NM frame detected by the detection unit 23a, rather than a newly generated NM frame by the transfer unit 23c.

[0041] When the detection unit 23a detects a wake-up signal, the activation unit 23b initiates a transition to the wake-up state, and the transfer unit 23c transfers the wake-up signal. In other words, when the detection unit 23a detects a wake-up signal, the second transceivers 23-25 ​​execute the process of restarting power to the MCU 21 and the process of transferring the wake-up signal almost simultaneously. Once power is restored to the MCU 21, it executes the necessary processes to transition to the wake-up state, such as executing an initial sequence. Therefore, it takes time for the MCU 21 to complete the transition to the wake-up state after power is restored. On the other hand, the processing of the transfer unit 23c is implemented by hardware circuitry and only requires the transmission of the wake-up signal to a predetermined communication line, so it does not take much time. Therefore, even if the processes of the startup unit 23b and the transfer unit 23c are executed simultaneously, the result is that the wake-up signal is transferred by the transfer unit 23c before the transition to the wake-up state, which is performed by the startup unit 23b, is completed.

[0042] [1-1-3. Terminal ECU] Each terminal ECU 5a to 5r is equipped with a CPU 51, a memory 52, and a third transceiver 54. The sleep state in terminal ECUs 5a to 5r includes a state in which power to the CPU 51 is cut off. Even in the sleep state, the functions of the third transceiver 54 are available.

[0043] Memory 52 stores programs that allow the CPU 51 to perform predetermined functions. The terminal ECUs 5a to 5r function as NM control units 53 by having the CPU 51 execute a program in memory 52. ​​The NM control units 53 are configured to generate NM frames, similar to the NM control unit 13 of the central ECU 1.

[0044] The third transceiver 54 of terminal ECU 5a is connected to the second transceiver 24 of zone ECU 2 via communication line 6d. Furthermore, the third transceiver 54 of terminal ECU 5a can communicate directly with terminal ECUs 5b and 5c, which are connected to communication line 6d. The explanation of the communication lines connecting terminal ECUs 5b to 5r is omitted.

[0045] The third transceiver 54 is configured to process NM frames. The third transceiver 54 includes a detection unit 54a, an activation unit 54b, and a transmission unit 54c. The functions of the third transceiver 54 are implemented by hardware circuits, similar to the first transceivers 15-17.

[0046] Each detection unit 54a is configured to detect a wake-up signal. Each startup unit 54b is configured to transition its node from sleep state to wake-up state when a wake-up signal is detected by each detection unit 54a. More specifically, each startup unit 54b controls the power supply to the CPU 51 to be resumed when a wake-up signal is detected by each detection unit 54a.

[0047] Each transmitting unit 54c is configured to transmit a frame. Each transmitting unit 54c is configured to transmit at least an NM frame generated by the NM control unit 53.

[0048] [1-2. Processing] The wake-up pre-processing performed by the central ECU1 and / or zone ECUs 2-4 will be explained using the flowchart shown in Figure 3. This process assumes a scenario where the vehicle is parked. When the vehicle is parked, the central ECU1, zone ECUs 2-4, and terminal ECUs 5a-5r are in a sleep state.

[0049] [1-2-1. Use Case 1] This use case illustrates a scenario where a node belonging to the second tier executes the wake-up pre-function.

[0050] For example, let's explain a case where this process is executed when a user uses the CarFinder service. CarFinder is a function of an application that notifies the user of the vehicle's location in an easy-to-understand manner, such as in a parking lot. Specifically, the CarFinder service is a function that informs the user of the vehicle's location by flashing lights or sounding the horn. In addition, the CarFinder service also has functions that automatically turn on the air conditioning or unlock the doors before the user gets into the vehicle.

[0051] As an example, suppose terminal ECU 5a controls the lights, terminal ECU 5b controls the horn, terminal ECU 5d controls the air conditioning, and terminal ECU 5e controls the doors. Terminal ECUs 5a, 5b, 5d, and 5e are located within the same zone.

[0052] Terminal ECUs 5a, 5b, 5d, and 5e, as well as Zone ECU 2, are classified as Group 1 as nodes necessary to provide the car finder service. First, the user initiates the Car Finder service from their smartphone. When the cloud receives the instruction signal from the smartphone, it sends an event to the central ECU1 instructing it to run the Car Finder.

[0053] When the wireless communication unit 14 of the central ECU1 receives an event instructing the execution of the car finder, it transitions the central ECU1 to the wake-up state. Next, the NM control unit 13 of the central ECU 1 generates an NM frame. More specifically, the NM control unit 13 generates a second frame in which the bit positions of the data fields corresponding to the first group are set to "1".

[0054] Next, the central ECU1 transmits an NM frame. Since the terminal ECUs 5a, 5b, 5d, and 5e, which are necessary to provide the car finder service, are nodes under the zone ECU2, the central ECU1 transmits an NM frame to communication line 6a.

[0055] Next, in S101, the detection unit 15a of the second transceiver 23 of the zone ECU 2 detects the NM frame transmitted to the communication line 6a as a wake-up signal. Next, in S102, the transfer unit 23c of the second transceiver 23 in the zone ECU 2 determines the transmission bus.

[0056] Next, in S103, Zone ECU2 transmits the wake-up signal. In other words, in S102 and S103, the zone ECU2 performs routing processing. For example, if the receiving bus is communication line 6a and the transmitting buses are predetermined to be communication lines 6d and 6e, the transfer unit 23c of the second transceiver 24 in the zone ECU2 transfers the wake-up signal to communication line 6d. Also, the transfer unit 23c of the second transceiver 25 in the zone ECU2 transfers the wake-up signal to communication line 6e. More specifically, the transfer units 23c of the second transceivers 24 and 25 convert the received NM frame to a protocol and transmit it as a wake-up signal to communication lines 6d and 6e.

[0057] Furthermore, in S104, the activation unit 23b of the second transceiver 23 provided in the zone ECU2 transitions the zone ECU2 from sleep state to wake-up state. Note that the routing process and the process in S104 start almost simultaneously and are executed in parallel, but the zone ECU2 actually transitions to the wake-up state after the routing process is completed.

[0058] Next, the detection unit 54a of terminal ECUs 5a and 5b detects the NM frame transmitted to communication line 6d as a wake-up signal. The detection unit 54a of terminal ECUs 5d and 5e detects the NM frame transmitted to communication line 6e as a wake-up signal.

[0059] Next, the activation units 54b of terminal ECUs 5a, 5b, 5d, and 5e transition their nodes from sleep state to wake-up state. Note that terminal ECUs other than terminal ECUs 5a, 5b, 5d, and 5e connected to communication line 6d or communication line 6e (i.e., terminal ECUs 5c and 5f) do not belong to the first group and therefore do not transition to the wake-up state. As described above, the second frame is generated by associating the bit positions in the data field with groups, and a node transitions to the wake-up state only when it receives a second frame that specifies the group to which it belongs. Furthermore, even if a terminal ECU does not have the function to process NM frames, that terminal ECU will not transition to the wake-up state.

[0060] Terminal ECU 5a controls the lights to flash, terminal ECU 5b controls the horn to sound, terminal ECU 5d controls the air conditioning to turn on, and terminal ECU 5e controls the doors to unlock.

[0061] [1-2-2. Use Case 2] This use case illustrates another scenario where a node belonging to the second tier performs the wake-up pre-function.

[0062] For example, let's explain a case where this process is executed when using a monitoring service. A monitoring service is a function that automatically activates a camera and takes pictures of the area around a vehicle when it is subjected to an impact, such as a hit-and-run while parked.

[0063] As an example, let's assume that terminal ECU 5k is an ECU connected to an impact sensor (not shown) that detects impacts to the vehicle, and terminal ECU 5h is an ECU for controlling the camera. Terminal ECUs 5h and 5k are located in the same zone.

[0064] Terminal ECUs 5h and 5k, and zone ECU 3 are classified as part of the second group of nodes necessary to implement monitoring services. First, when the impact sensor detects an impact on the vehicle, the terminal ECU 5k transitions to a wake-up state.

[0065] Next, the NM control unit 53 of the terminal ECU 5k generates an NM frame. More specifically, the NM control unit 53 generates a second frame in which the bit positions of the data field corresponding to the second group are set to "1".

[0066] Next, terminal ECU5k transmits an NM frame over communication line 6g. Next, in S101, the detection unit 23a of the second transceiver 25 in the zone ECU 3 detects the NM frame transmitted to the communication line 6g as a wake-up signal.

[0067] Next, in S102, the transfer unit 23c of the second transceiver 25 in the zone ECU 3 determines the transmission bus. Next, in S103, Zone ECU3 transmits the wake-up signal.

[0068] In other words, in steps S102 and S103, the zone ECU 3 performs routing processing. For example, if it is predetermined that the receiving bus is communication line 6g and the transmitting bus is communication line 6f, the transfer unit 23c of the second transceiver 24 in the zone ECU 3 transfers the wake-up signal to communication line 6f.

[0069] Furthermore, in S104, the activation unit 23b of the second transceiver 25 provided in the zone ECU 3 transitions the zone ECU 3 from sleep state to wake-up state. Note that the routing process and the process in S104 start almost simultaneously and are executed in parallel, but the zone ECU 3 actually transitions to the wake-up state after the routing process is completed.

[0070] Next, the detection unit 54a of the terminal ECU 5h detects the NM frame transmitted to the communication line 6f as a wake-up signal. Next, the startup unit 54b of terminal ECU 5h transitions terminal ECU 5h from sleep state to wake-up state. Note that terminal ECUs other than terminal ECU 5h connected to communication line 6f do not belong to the second group and therefore do not transition to the wake-up state. The terminal ECU5h controls the camera to activate and take pictures of the area around the vehicle.

[0071] [1-2-3. Use Case 3] This use case illustrates a scenario where nodes belonging to the first tier and nodes belonging to the second tier execute the wake-up pre-function.

[0072] For example, let's explain a case where this process is executed when a user utilizes the key service. The key service is a function that unlocks the doors when a user with a smart key approaches the vehicle.

[0073] For example, suppose Zone ECU4 is the ECU for authenticating the smart key, and Terminal ECU5e is the ECU for controlling the doors. Terminal ECU5e is located under Zone ECU2.

[0074] Terminal ECU5e and zone ECU2,4 are classified as the third group, as they are nodes necessary to realize key services. First, when the user enters a certain distance from the vehicle, the Zone ECU4 receives a signal indicating key information X transmitted from the smart key. Then, the Zone ECU4 transitions to the wake-up state.

[0075] Next, Zone ECU4 compares key information X with key information Y stored in Zone ECU4's memory to determine whether they match. If they match, Zone ECU4 determines that authentication is successful; if they do not match, it determines that authentication is unsuccessful.

[0076] If authentication is deemed successful, the NM control unit 22 of zone ECU4 generates an NM frame. More specifically, the NM control unit 22 generates a second frame in which the bit position of the data field corresponding to the third group is set to "1".

[0077] Next, Zone ECU4 transmits an NM frame. Since the terminal ECU5e, which is necessary to realize the key service, is a node under Zone ECU2, Zone ECU4 cannot directly transmit an NM frame to terminal ECU5e. Therefore, Zone ECU4 transmits the NM frame to terminal ECU5e via Central ECU1 and Zone ECU2, and thus transmits the NM frame over communication line 6c.

[0078] Next, in S101, the detection unit 15a of the first transceiver 17 of the central ECU 1 detects the NM frame transmitted to the communication line 6c as a wake-up signal. Next, in S102, the transfer unit 15c of the first transceiver 17, which is located in the central ECU 1, determines the transmission bus.

[0079] Next, in S103, the central ECU1 transmits the wake-up signal. In other words, in S102 and S103, the central ECU 1 performs routing processing. For example, if it is predetermined that the receiving bus is communication line 6c and the transmitting bus is communication line 6a, the transfer unit 15c of the first transceiver 15 in the central ECU 1 transfers the wake-up signal to communication line 6a.

[0080] Furthermore, in S104, the activation unit 15b of the first transceiver 17 of the central ECU 1 transitions the central ECU 1 from sleep state to wake-up state. Note that the routing process and the process in S104 start almost simultaneously and are executed in parallel, but the central ECU 1 actually transitions to the wake-up state after the routing process is completed.

[0081] Next, the detection unit 23a of the second transceiver 23 in the zone ECU 2 detects the NM frame transmitted to the communication line 6a as a wake-up signal. The subsequent processing in Zone ECU2 is the same as in [1-2-1. Use Case 1], but for example, if it is predetermined that the receiving bus is communication line 6a and the transmitting buses are communication lines 6d and 6e, the transfer unit 23c of the second transceiver 24 in Zone ECU2 transfers the wake-up signal to communication line 6d. Also, the transfer unit 23c of the second transceiver 25 in Zone ECU2 transfers the wake-up signal to communication line 6e. More specifically, the transfer units 23c of the second transceivers 24 and 25 convert the received NM frame to a protocol and transmit it as a wake-up signal to communication lines 6d and 6e.

[0082] Furthermore, the activation unit 23b of the second transceiver 23 provided in the zone ECU2 transitions the zone ECU2 from sleep state to wake-up state. Note that the zone ECU2 actually transitions to the wake-up state only after the routing process is completed.

[0083] Next, the detection unit 54a of the terminal ECU 5e detects the NM frame transmitted to the communication line 6e as a wake-up signal. Next, the startup unit 54b of the terminal ECU 5e transitions its node from sleep state to wake-up state. Note that terminal ECUs other than terminal ECU 5e that are connected to communication line 6d or communication line 6e do not belong to the third group and therefore do not transition to the wake-up state. The terminal ECU5e controls the unlocking of the doors.

[0084] [1-3. Effects] According to the embodiments described in detail above, the following effects can be obtained.

[0085] (1a) When a wake-up signal is detected by the detection units 15a and 23a, the transfer units 15c and 23c are configured to transmit the wake-up signal to a different communication line from the one on which the wake-up signal was detected, while remaining in sleep mode. In other words, the central ECU 1 and zone ECUs 2 to 4 have a wake-up pre-function.

[0086] Let's consider a scenario where the central ECU1 and zone ECUs 2-4 do not have a wake-up pre-function. For example, as in [1-2-1. Use Case 1], when nodes transition to the wake-up state sequentially from the first to the third layer, the wake-up signal is sent to the node in the second layer only after the node in the first layer has completed its transition to the wake-up state. Then, the wake-up signal is sent to the node in the third layer only after the node in the second layer has completed its transition to the wake-up state. In this case, it takes a lot of time for all the nodes in all layers to transition to the wake-up state. In other words, it takes the sum of the time it takes for the node in the first layer to transition to the wake-up state, the time it takes for the node in the second layer to transition to the wake-up state, and the time it takes for the node in the third layer to transition to the wake-up state.

[0087] However, with the above configuration, a wake-up signal is sent to the node belonging to the third layer before the node belonging to the second layer transitions to the wake-up state. In other words, while the node belonging to the second layer is transitioning to the wake-up state, the node belonging to the third layer is also transitioning to the wake-up state. Therefore, the time required for all nodes to transition to the wake-up state can be shortened. Consequently, in a communication system 100 in which multiple nodes are connected to form a hierarchical structure, it is possible to suppress the increase in the time required when multiple nodes are sequentially woken up for each layer.

[0088] (1b) The NM frame contains a wake-up signal. With this configuration, an existing frame can be used as the wake-up signal. Therefore, there is no need to provide a dedicated communication line to implement the wake-up pre-function.

[0089] (1c) The transfer units 15c and 23c transmit the wake-up signal to a predetermined communication line depending on the communication line on which the wake-up signal was received. With this configuration, since the processing is predetermined, the transfer units 15c and 23c can transmit the wake-up signal more quickly than a configuration that identifies the contents of the frame and determines which communication line to transmit the wake-up signal to.

[0090] (1d) When a wake-up signal is detected by the detection units 15a and 23a, the activation units 15b and 23b perform a transition to the wake-up state, and the transfer units 15c and 23c transmit the wake-up signal. At this time, the transfer units 15c and 23c transmit the wake-up signal before the transition to the wake-up state performed by the activation units 15b and 23b is completed. With this configuration, since the transfer units 15c and 23c transmit the wake-up signal while the node is transitioning to the wake-up state, the wake-up signal can be transmitted more quickly compared to a configuration in which the wake-up signal is transmitted after the node has completed its transition to the wake-up state.

[0091] (1e) The communication system 100 is configured in multiple layers, comprising a central ECU 1, multiple zone ECUs 2-4, and multiple terminal ECUs 5a-5r. Here, as the number of layers increases, the number of times NM frames are transferred also increases, so the time it takes for all layers of nodes to transition to the wake-up state tends to increase. However, since the central ECU 1 and zone ECUs 2-4 have a wake-up pre-function, they can transfer NM frames quickly. Therefore, even with multiple layers, it is possible to suppress the increase in the time it takes for all layers of nodes to transition to the wake-up state.

[0092] [1-4. Correspondence] In the above embodiment, the central ECU 1 corresponds to the first communication device, the multiple zone ECUs 2 to 4 correspond to the multiple second communication devices, and the terminal ECUs 5a to 5r correspond to the multiple third communication devices.

[0093] [2. Other Embodiments] While embodiments of this disclosure have been described above, it goes without saying that this disclosure is not limited to the embodiments described above and can take various forms.

[0094] (2a) In the above embodiment, the communication system 100 is shown as comprising a central ECU 1, a plurality of zone ECUs 2 to 4, and a plurality of terminal ECUs 5a to 5r, forming a configuration of three layers. However, the connection configuration of the nodes constituting the communication system is not limited to this. For example, as shown in the modified example 1 of the communication system 200 in Figure 4, the communication system 200 may comprise a plurality of domain controllers 202 to 205 and a plurality of terminal ECUs 5a to 5x. Note that the same reference numerals as in the above embodiment indicate the same configuration, and refer to the preceding description.

[0095] Multiple domain controllers 202-205 are connected via communication line 201 to enable data transmission and reception. Each domain controller 202-205 is connected to one of the multiple terminal ECUs 5a-5x via one of the communication lines 6d-6k to enable data transmission and reception.

[0096] Domain controllers 202-205 are communication devices that can control the operation of terminal ECUs 5a-5x connected to domain controllers 202-205. Furthermore, domain controller 204 manages domain controllers 202, 203, and 205, thereby achieving coordinated control for the entire vehicle.

[0097] Domain controllers 202-205, like zone ECUs 2-4, are equipped with an MCU 21 and second transceivers 23-25. In other words, domain controllers 202-205 have a wake-up pre-function. Furthermore, domain controllers 202-205 function as NM control units 22 by having the CPU execute a program in memory.

[0098] The multiple terminal ECUs 5s to 5x, like the multiple terminal ECUs 5a to 5r, are equipped with a CPU 51, a memory 52, and a third transceiver 54. Furthermore, the terminal ECUs 5s to 5x function as an NM control unit 53 by having the CPU 51 execute a program stored in the memory 52.

[0099] The above modified example 1 also achieves the effects (1a) to (1d) of the embodiment described above. In the above modified example 1, the domain controller 204 corresponds to the first communication device, the domain controllers 202, 203, and 205 correspond to multiple second communication devices, and the terminal ECUs 5a to 5x correspond to multiple third communication devices.

[0100] (2b) In the above embodiment, a configuration was illustrated in which the central ECU 1 is equipped with first transceivers 15 to 17 and the zone ECUs 2 to 4 are equipped with second transceivers 23 to 25. However, as in the communication system 300 of modified example 2 shown in Figure 5, the functions of the first transceivers 15 to 17 may be integrated into a single first transceiver 315. The first transceiver 315 may be a single transceiver module. The first transceiver 315 may be equipped with each communication port connected to each of the communication lines 6a to 6c.

[0101] Furthermore, the functions of the second transceivers 23 to 25 may be integrated into a single second transceiver 323. The second transceiver 323 may also be a single transceiver module. The configurations of zone ECUs 3 and 4 are not shown in the diagram, but they have the same configuration as zone ECU 2. The second transceiver 323 of zone ECU 2 may have communication ports connected to each of the communication lines 6a, 6d, and 6e. The second transceiver 323 of zone ECU 3 may have communication ports connected to each of the communication lines 6b, 6f, and 6g. The second transceiver 323 of zone ECU 4 may have communication ports connected to each of the communication lines 6c, 6h, and 6i.

[0102] Furthermore, in the central ECU1, a well-known semiconductor fuse (hereinafter referred to as eFuse) that connects / disconnects the power line (i.e., turns the power supply from a battery not shown) may be placed in the power supply path (i.e., the power line) that supplies power to the MPU11 and MCU12. In the following, a device that connects / disconnects the power line, such as an eFuse, may be referred to as a power relay L.

[0103] A power line is connected to the first transceiver 315 and the power relay L, and the first transceiver 315 is constantly supplied with power. Power can be supplied to the MPU 11 and MCU 12 via the power relay L. When the wake-up signal is detected by the detection unit 15a, the startup unit 15b outputs a relay drive signal to the power relay L, controlling the power relay L to be energized (ON). This resumes power supply to the MPU 11 and MCU 12.

[0104] A power line is connected to the second transceiver 323 and the power relay L, and the second transceiver 323 is constantly supplied with power. Power can also be supplied to the MCU 21 via the power relay L. When the wake-up signal is detected by the detection unit 23a, the startup unit 23b outputs a relay drive signal to the power relay L, controlling the power relay L to be energized (ON). This resumes power supply to the MCU 21.

[0105] The terminal ECUs 5a to 5r may also be configured to include a power relay L. More specifically, a power line is connected to the third transceiver 54 and the power relay L, and the third transceiver 54 is constantly supplied with power. Power can be supplied to the CPU 51 via the power relay L. When the wake-up signal is detected by the detection unit 54a, the startup unit 54b outputs a relay drive signal to the power relay L, controlling the power relay L to be energized (ON). This resumes power supply to the CPU 51. Furthermore, the domain controllers 202-205 in Modification Example 1 may have the same configuration as the zone ECU2 in Modification Example 2.

[0106] (2c) In the above embodiment, an example was given in which the central ECU 1, zone ECUs 2 to 4, and terminal ECUs 5a to 5r are equipped with NM control units 13, 22, and 53 configured to generate NM frames. However, some nodes do not need to be equipped with NM control units. In this embodiment, only the node that is likely to wake up first is equipped with an NM control unit, and the nodes other than the one that is likely to wake up first do not need to be equipped with an NM control unit. In this embodiment, if the node that wakes up first generates and transmits an NM frame, the other nodes do not need to generate an NM frame, as they only need to forward the NM frame. Taking use case 1 as an example, only the central ECU 1 that wakes up first is equipped with an NM control unit.

[0107] Furthermore, in the above embodiment, a configuration in which the first transceivers 15-17, the second transceivers 23-25, and the third transceiver 54 are capable of processing NM frames was illustrated. However, some nodes may not be able to process NM frames. In this embodiment, nodes that do not belong to any group do not need to be woken up by an NM frame, so the transceivers do not need to have the function of processing NM frames.

[0108] (2d) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configuration of the above embodiment may be omitted. Also, at least some of the configuration of the above embodiment may be added to or replaced with the configuration of other above embodiments.

[0109] (2e) In addition to the communication systems 100, 200, and 300 described above, this disclosure can also be implemented in various forms, such as the individual devices that make up the components of the communication systems 100, 200, and 300, and the wake-up pre-processing method.

[0110] [Technical Concept Disclosed in This Specified Specification] [Item 1] A communication system (100,200,300), The communication device comprises a first communication device (1,204), one or more second communication devices (2-4,202,203,205), and one or more third communication devices (5a-5x), The one or more second communication devices are connected to the first communication device via communication lines (6a~6c, 201) so that they can communicate directly with the first communication device. The one or more third communication devices are connected to communication lines (6d to 6k) so as to be able to communicate directly with the first communication device or the one or more second communication devices. The first communication device, the one or more second communication devices, and the one or more third communication devices each include, in order, a first transceiver (15-17,315), a second transceiver (23-25,323), and a third transceiver (54). It has a wake-up state, which is the normal operating state, and a sleep state, which is a low-power operating state in which some or all functions other than those provided by each transceiver are restricted. The first transceiver, the second transceiver, and the third transceiver are, A detection unit (15a, 23a, 54a) configured to detect a wake-up signal, which is a signal that instructs the system to transition to the wake-up state, When the wake-up signal is detected by the detection unit, the startup unit (15b, 23b, 54b) is configured to transition its own communication device from the sleep state to the wake-up state, Equipped with, The first transceiver and / or the second transceiver are A communication system comprising a transfer unit (15c, 23c) configured to transmit the wake-up signal to a different communication line from the one on which the wake-up signal was detected, while remaining in sleep mode, when the wake-up signal is detected by the detection unit.

[0111] [Item 2] The communication system described in item 1, The first transceiver, the second transceiver, and the third transceiver are, It is configured to process NM frames, which are frames used to manage the state of the communication system, A communication system in which the aforementioned NM frame includes the wake-up signal.

[0112] [Item 3] A communication system as described in item 1 or item 2, The transfer unit is a communication system that transmits the wake-up signal to a predetermined communication line according to the communication line that received the wake-up signal.

[0113] [Item 4] A communication system described in any one of items 1 through 3, The first communication device and / or the one or more second communication devices are When the detection unit detects the wake-up signal, the activation unit performs the transition to the wake-up state, and the transfer unit transmits the wake-up signal. A communication system in which the wake-up signal is transmitted by the transfer unit before the transition to the wake-up state, which is performed by the startup unit, is completed.

[0114] [Item 5] A communication system described in any one of items 1 through 4, The first communication device is a communication device that integrates the one or more second communication devices to achieve coordinated control of the entire communication system. The one or more second communication devices are provided in each zone that divides the area on which the communication system is installed, and are communication devices that perform control of the one or more third communication devices located within the zone. A communication system in which the one or more third communication devices are connected to a communication line so as to be able to communicate directly with any of the one or more second communication devices. [Explanation of Symbols]

[0115] 1...Central ECU, 2-4...Zone ECUs, 5a-5x...Terminal ECUs, 6a-6k, 201...Communication lines, 15-17, 315...First transceivers, 15a, 23a, 54a...Detection units, 15b, 23b, 54b...Activation units, 15c, 23c...Transfer units, 23-25, 323...Second transceivers, 54...Third transceiver, 100, 200, 300...Communication systems, 202-205...Domain controllers.

Claims

1. A communication system (100, 200, 300), The communication device comprises a first communication device (1,204), one or more second communication devices (2-4,202,203,205), and one or more third communication devices (5a-5x), The one or more second communication devices are connected to the first communication device via communication lines (6a to 6c, 201) so that they can communicate directly with the first communication device. The one or more third communication devices are connected to a communication line (6d to 6k) so as to be able to communicate directly with the first communication device or the one or more second communication devices. The first communication device, the one or more second communication devices, and the one or more third communication devices each include, in order, a first transceiver (15-17, 315), a second transceiver (23-25, 323), and a third transceiver (54). It has a wake-up state, which is the normal operating state, and a sleep state, which is a low-power operating state in which some or all functions other than those provided by each transceiver are restricted. The first transceiver, the second transceiver, and the third transceiver are, A detection unit (15a, 23a, 54a) configured to detect a wake-up signal, which is a signal that instructs the system to transition to the wake-up state, When the wake-up signal is detected by the detection unit, the startup unit (15b, 23b, 54b) is configured to transition its own communication device from the sleep state to the wake-up state, Equipped with, The first transceiver and / or the second transceiver are A communication system comprising a transfer unit (15c, 23c) configured to transmit the wake-up signal to a different communication line from the one on which the wake-up signal was detected, while remaining in sleep mode, when the wake-up signal is detected by the detection unit.

2. A communication system according to claim 1, The first transceiver, the second transceiver, and the third transceiver are, It is configured to process NM frames, which are frames used to manage the state of the communication system, A communication system in which the NM frame includes the wake-up signal.

3. A communication system according to claim 1 or claim 2, The transfer unit is a communication system that transmits the wake-up signal to a predetermined communication line according to the communication line on which the wake-up signal was received.

4. A communication system according to claim 1 or claim 2, The first communication device and / or the one or more second communication devices are When the detection unit detects the wake-up signal, the activation unit performs a transition to the wake-up state, and the transfer unit transmits the wake-up signal. A communication system in which the wake-up signal is transmitted by the transfer unit before the transition to the wake-up state, which is performed by the activation unit, is completed.

5. A communication system according to claim 1 or claim 2, The first communication device is a communication device that integrates the one or more second communication devices to achieve coordinated control of the entire communication system. The one or more second communication devices are provided in each zone that divides the area on which the communication system is installed, and are communication devices that perform control of the one or more third communication devices located within the zone. A communication system in which the one or more third communication devices are connected to a communication line so as to be able to communicate directly with any of the one or more second communication devices.

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