JP2015154189A - Communication system, gateway device, communication node and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption in a multiplex communication system including a plurality of communication nodes.SOLUTION: A gateway device includes a control section which identifies a communication node to which data are transmitted from one of a plurality of communication buses, increases a count value of a transmission counter for data associated with the communication data, and disables the data from being communicated by the one communication bus if the count value is equal to or greater than a threshold value. After an ignition of a vehicle is turned off and the gateway device is shifted to a sleep state, the control section identifies a communication node to which data received by a receiving section are transmitted. The communication node includes: a communication section for transmitting data to one communication bus and receiving data from one communication bus; and a control section which shifts to the sleep state if it is determined that a state where the communication node can be shifted to the sleep state, and data are not received from the other communication nodes for a predetermined time.

Description

  The present invention relates to a multiplex communication system in which a plurality of communication nodes transmit / receive signals to / from each other via a communication line.

  In recent years, for example, the number of electrical components and electrical devices mounted on automobiles has been increasing with the increase in functionality and performance of vehicles, and wiring for connecting electrical components and electrical devices is complicated and large. It is getting bigger. Therefore, a multiplex communication system in which a plurality of devices are connected to each other via a communication line and communication is performed between the devices has been put into practical use.

  When such a multiplex communication system is mounted on, for example, an automobile, it depends on the battery power source when the engine is stopped, so that it is necessary to reduce power consumption as much as possible. For this reason, when the system may stop the operation, the communication node, which is each device constituting the multiplex communication system, stops functioning and the minimum necessary to restart when requested to start. A so-called sleep state in which only power is consumed is entered.

  Each communication node constituting the multiplex communication system determines whether or not it is possible to shift the operation state to the sleep state that consumes less power than the normal state, and determines that the transition to the sleep state is not possible If a notification signal is sent to notify all the other communication nodes, and it is determined that the transition to the sleep state is possible, the notification signal from the other communication node is continued for a predetermined time or longer. A technique for switching the operation state of a communication node to a sleep state when it is determined that it has not been received is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 9-135257

  A sleep state in which one communication node among a plurality of communication nodes constituting a multiplex communication system transmits data to a communication line due to an unexpected situation such as occurrence of an abnormality in the communication node itself or noise. Suppose you want to wake up from.

  There are various functions for a communication node that has entered the sleep state to wake up when the ignition is turned off. Normally, a wake-up communication node transmits necessary information and then transitions to a sleep state again. However, it is assumed that the same communication node continues to wake up and continue to wake up the communication line due to an unintended software bug or an unexpected rare case at the time of development.

  Even if the communication node other than the waked-up communication node can shift to the sleep state, the communication node receives data and cannot switch the operation state to the sleep state.

  If the situation in which the operating state cannot be switched to the sleep state continues, power consumption may increase and the battery may rise. In some cases, the battery may be discharged while the ignition is turned off for several days, and the battery may go up.

  An object of the present invention is to reduce power consumption in a multiple communication system having a plurality of communication nodes.

A communication system according to an embodiment of the disclosure includes:
A communication node mounted on a vehicle and connected to a plurality of communication buses, and a gateway device connected between the plurality of communication buses and relaying communication between the communication nodes connected to different communication buses A communication system comprising:
The gateway device is
A receiving unit for receiving data transmitted by a communication node connected to one communication bus of the plurality of communication buses;
A communication node that transmits data from the one communication bus is specified, and a count value of a transmission counter that counts the number of transmissions of data associated with the communication node that transmits the data is increased. A control unit that disables data communication through the one communication bus when the count value is equal to or greater than a threshold value,
The control unit specifies a communication node that transmits data received by the receiving unit after the ignition of the vehicle is turned off and the gateway device enters a sleep state.
The communication node connected to the one communication bus is:
A communication unit for transmitting data to the one communication bus and receiving data from the one communication bus;
And a control unit that shifts to the sleep state when the communication node determines that the node can shift to the sleep state and does not receive data from another communication node for a predetermined time.

  According to the disclosed embodiment, power consumption can be reduced in a multiplex communication system having a plurality of communication nodes.

It is a figure which shows one Example of a communication system. It is a figure which shows one Example of a 1st communication node. It is a figure which shows an example of a flame | frame. It is a figure which shows one Example of a 5th communication node. It is a flowchart which shows one Example (the 1) of operation | movement of a 1st communication node. It is a flowchart which shows one Example (the 2) of operation | movement of a 1st communication node. It is a flowchart which shows one Example of operation | movement of a 5th communication node. It is a figure which shows one Example of a communication system. It is a figure which shows one Example of a 6th communication node. It is a figure which shows one Example of a 10th communication node.

Next, the form for implementing this invention is demonstrated, referring drawings based on the following Examples. Examples described below are merely examples, and embodiments to which the present invention is applied are not limited to the following examples.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

<Example>
<Communication system>
FIG. 1 shows an embodiment of a communication system.

  The communication system is mounted on a moving body such as a vehicle. One embodiment of a communication system is mounted on a vehicle, and a LAN such as CAN (Controller Area Network) or LIN (Local Interconnect Network) is applied. The communication system can be applied to information LAN, powertrain LAN, body LAN, and the like.

  Further, FlexRay (registered trademark) may be applied to the communication system.

  Each communication node is realized by a control device such as an electronic control unit (ECU). Moreover, a sensor, an actuator, etc. may be mounted in each communication node.

  The communication system includes a first communication node 100, a second communication node 200, a third communication node 300, a fourth communication node 400, and a fifth communication node 500.

  The first communication node 100 and the second communication node 200 are connected by wire through the first communication bus 10. The third communication node 300 to the fourth communication node 400 are connected by wire through the second communication bus 20. The fifth communication node 500 is interposed between the first communication bus 10 and the second communication bus 20. The fifth communication node 500 is a gateway device that relays communication between the communication node connected to the first communication bus 10 and the communication node connected to the second communication bus 20.

  The first communication node 100 to the fifth communication node 500 are connected to the battery 50 via fuses 150, 250, 350, 450, and 550, respectively.

  Although FIG. 1 shows a case where a communication system is configured by five communication nodes, it may be configured by 3-4 communication nodes, or may be configured by six or more communication nodes. A communication node connected to the first communication bus 10, a communication node connected to the second communication bus 20, and communication interposed between the first communication bus 10 and the second communication bus 20. A communication system can be configured by nodes.

  When CAN is applied to the communication system, the first communication bus 10 and the second communication bus 20 include two communication lines (CAN bus) having a twisted pair configuration. One of the CAN bus twisted pair lines is a bus called CAN High (hereinafter referred to as CANH) and the other is referred to as CAN Low (hereinafter referred to as CANL). Termination resistors (not shown) are connected to both ends of each of the first communication bus 10 and the second communication bus 20. In FIG. 1, CANH and CANL are represented by a single solid line.

  The first communication node 100, the second communication node 200, and the fifth communication node 500 continue to transmit a low level signal in accordance with CSMA / CD (Carrier Sense Multiple Access / Collision Detection). The communication node preferentially communicates, and the communication node that has lost the collision (transmitted a high level signal) waits for transmission of the next opportunity. That is, among the first communication node 100, the second communication node 200, and the fifth communication node 500, a communication node that has continued to transmit a low-level signal performs communication via the first communication bus 10. Communication nodes other than the communication node that has continued to transmit the low level signal wait until the next opportunity.

  Similarly, for the third communication node 300, the fourth communication node 400, and the fifth communication node 500, according to CSMA / CD, a communication node that has continued to transmit a low-level signal performs communication preferentially, The communication node that lost the collision waits for the next opportunity transmission. That is, among the third communication node 300, the fourth communication node 400, and the fifth communication node 500, the communication node that has continued to transmit a low-level signal performs communication via the second communication bus 20. The communication nodes other than the communication node that has continued to transmit the low level signal wait until the next opportunity.

<First communication node 100>
FIG. 2 shows an embodiment of the first communication node 100. FIG. 2 mainly shows the hardware configuration of the first communication node 100. The hardware configuration of the second communication node 200 to the fourth communication node 400 can also be applied to FIG.

  The first communication node 100 includes a communication transceiver 102, a communication circuit 104, and a CPU 106.

  The communication transceiver 102 is connected to the first communication bus 10 and transmits data from the communication circuit 104 to the first communication bus 10 and receives data from the first communication bus 10 under the control of the communication driver. And input to the communication circuit 104. When transmitting data, the communication transceiver 102 sends an inversion signal to CANH and CANL. When receiving data, the communication transceiver 102 determines whether the data on the first communication bus 10 is “1” or “0” from the voltage difference between CANH and CANL.

  The communication circuit 104 is connected to the communication transceiver 102 and performs serial communication with other communication nodes via the first communication bus 10. The communication circuit 104 transmits data from the CPU 106 from the communication transceiver 102 and inputs data from the communication transceiver 102 to the CPU 106.

  The CPU 106 is connected to the communication circuit 104 and executes communication processing executed by the communication circuit 104 and processing for controlling the first communication node 100. The CPU 106 is supplied with battery power (+ B power) and an IG (ignition) signal.

  The CPU 106 controls the operation state of the first communication node 100. The operation state of the first communication node 100 becomes a normal state when the CPU 106 is operating in the normal mode. When the CPU 106 enters the sleep state, power consumption associated with the operation of the CPU 106 is reduced and the communication circuit 104 is connected. Since the power supply is interrupted, the sleep state, which is a state of low power consumption, is entered.

  The first communication node 100 transmits and receives signals between the second communication node 200 and the fifth communication node 500.

  FIG. 3 shows a frame structure of a signal transmitted and received in the communication system.

  A transmission signal from the first communication node 100 includes a start of frame (SOF) bit, an ID, a data field, a CRC slot, an ACK (acknowledge) slot, and an end of frame (EOF). Frame).

  The start of frame bit indicates the head of the frame and is indicated by a dominant (logic 0) bit.

  The ID identifies the message and indicates the priority of the message. The ID may be represented by 11 bits (standard frame) or 29 bits (extended frame). The ID is also called a data ID.

  Various data of 0 to 8 bytes, a switch signal, a control signal, and the like are attached to the Data field.

  CRC indicates a cyclic redundancy check. The CRC includes a 15-bit cyclic redundancy check code and a recessive delimiter bit. The CRC field is used for error detection.

  The ACK (acknowledge) slot is transmitted at the end of the message when the message is correctly received. The transmitting node preferably checks the presence or absence of an ACK bit on the communication bus, and if no ACK is detected, attempts to transmit again.

  The end of frame indicates the end position of the data frame or the remote frame. The end-of-frame is composed of 7 bits, and all bit levels are “recessive”.

  The data field of the transmission signal from the first communication node 100 notifies the other communication nodes that the first communication node 100 is in a state where it cannot enter the sleep state (hereinafter referred to as “sleep impossible state”). In some cases, a bit (hereinafter referred to as a “sleep disable bit”) SLNG as broadcast information is included.

  When the first communication node 100 is in a state where some control must be performed, or when the first communication node 100 controls an actuator or the like, the first communication node 100 is in a sleep disabled state. Judgment is made, and the sleep disable bit SLNG is set to active (in this embodiment, “1”) indicating that the sleep disable state is transmitted.

  Even if the first communication node 100 is in the sleep capable state, the first communication node 100 enters the sleep state if the sleep disable bit SLNG attached to the frame transmitted from another communication node is active. Does not migrate.

  In addition, when the first communication node 100 does not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or more from another communication node, all the communication nodes including the first communication node are in the sleep state. It is determined that it is possible to enter the sleep state, and the normal state is shifted to the sleep state.

<Fifth communication node 500>
FIG. 4 shows an embodiment of the fifth communication node 500. FIG. 5 mainly shows the hardware configuration of the fifth communication node 500.

  The fifth communication node 500 includes a first communication transceiver 502, a first communication circuit 504, a first communication bus fixing circuit 506, a second communication transceiver 508, and a second communication circuit 510. , A second communication bus fixing circuit 512, and a CPU 514.

  The first communication transceiver 502 is connected to the first communication bus 10 and transmits data from the first communication circuit 504 to the first communication bus 10 under the control of the communication driver. Data from 10 is received and input to the first communication circuit 504. When transmitting data, the first communication transceiver 502 sends an inverted signal to CANH and CANL. When receiving data, the first communication transceiver 502 determines whether the data on the first communication bus 10 is “1” or “0” from the voltage difference between CANH and CANL. .

  The first communication circuit 504 is connected to the first communication transceiver 502 and performs serial communication with other communication nodes via the first communication bus 10. The first communication circuit 504 transmits the transmission data from the CPU 514 from the first communication transceiver 502 and inputs the reception data from the first communication transceiver 502 to the CPU 106.

  The first communication bus fixing circuit 506 fixes the first communication bus 10 to the dominant side in accordance with a signal from the CPU 514 (hereinafter referred to as “first abnormal wakeup signal”). In the example illustrated in FIG. 4, the first communication bus fixing circuit 506 includes an npn transistor 5062, a first resistor 5064, and a second resistor 5066. The collector of the npn transistor 5062 is connected to the first communication bus 10, the emitter is grounded, and the base is connected to the first resistor 5064. Another terminal different from the terminal connected to the npn transistor 5062 of the first resistor 5064 is connected to the CPU 514. Further, the base and emitter of npn transistor 5062 are connected via a second resistor 5066. The first communication bus fixing circuit 506 may be configured with a configuration different from the example shown in FIG.

  The CPU 514 outputs a first abnormal wakeup signal to the first communication bus fixing circuit 506 in a predetermined case. The npn transistor 5062 is turned on by the first abnormal wakeup signal from the CPU 514, and a current flows from the collector of the npn transistor 5062 toward the emitter. As a result of the current flowing from the collector of npn transistor 5062 toward the emitter, first communication bus 10 is fixed to the dominant.

  The second communication transceiver 508 is connected to the second communication bus 20 and transmits data from the second communication circuit 510 to the second communication bus 20 under the control of the communication driver. 20 is received and input to the second communication circuit 510. When transmitting data, the second communication transceiver 508 sends an inverted signal to CANH and CANL. When receiving data, the second communication transceiver 508 determines whether the data on the second communication bus 20 is “1” or “0” from the voltage difference between CANH and CANL. .

  The second communication circuit 510 is connected to the second communication transceiver 508 and performs serial communication with other communication nodes via the second communication bus 20. The second communication circuit 510 transmits the transmission data from the CPU 514 from the second communication transceiver 508 and inputs the reception data from the second communication transceiver 508 to the CPU 514.

  The second communication bus fixing circuit 512 fixes the second communication bus 20 to the dominant side in accordance with a signal from the CPU 514 (hereinafter referred to as “second abnormal wakeup signal”). In the example illustrated in FIG. 4, the second communication bus fixing circuit 512 includes an npn transistor 5122, a first resistor 5124, and a second resistor 5126. The collector of the npn transistor 5122 is connected to the second communication bus 20, the emitter is grounded, and the base is connected to the first resistor 5124. Another terminal different from the terminal connected to the npn transistor 5122 of the first resistor 5124 is connected to the CPU 514. Furthermore, the base and emitter of npn transistor 5122 are connected via a second resistor 5126. The second communication bus fixing circuit 512 may be configured with a configuration different from the example shown in FIG.

  The CPU 514 outputs a second abnormal wakeup signal to the second communication bus fixing circuit 512 in a predetermined case. By the second abnormal wakeup signal from the CPU 514, the npn transistor 5122 is turned on, and a current flows from the collector of the npn transistor 5122 toward the emitter. As a result of the current flowing from the collector of npn transistor 5122 toward the emitter, second communication bus 20 is fixed to the dominant.

  The CPU 514 is connected to the first communication circuit 504 and the second communication circuit 510, and executes communication processing executed by the first communication circuit 504 and processing for controlling the fifth communication node 500. The CPU 514 is supplied with battery power (+ B power) and an IG (ignition) signal. The CPU 514 receives an IG OFF signal as an IG signal when the IG is turned off, and an IG ON signal as an IG signal when the IG is turned on.

  The CPU 514 controls the operation state of the fifth communication node 500. The operation state of the fifth communication node 500 is a normal state when the CPU 514 is operating in the normal mode. When the CPU 514 enters the sleep state, the power consumption associated with the operation of the CPU 514 is reduced and the first communication is performed. Since the power supply to the circuit 504 is interrupted, a sleep state in which power consumption is low is entered.

  The CPU 514 includes a timer that measures a specified time and one or more counters that count the number of transmission operations. Each counter is associated with a communication node. The CPU 514 performs the following process after the IG OFF signal is input and the sleep state is entered until the IG ON signal is input.

  When the IG OFF signal is input to the CPU 514 and the sleep state is entered, the first communication bus 10 enters the bus sleep state, which is the Hi state. When there is no communication data, the communication bus 10 is in a Hi state.

  The CPU 514 determines whether a transmission operation has been performed for each communication node during a specified time. The specified time is preferably longer than the period of transition to the sleep state, and may be, for example, about 1 hour. The CPU 514 detects the edge of the first communication bus 10 to identify the communication node that has performed the transmission operation. An edge is detected when the communication bus 10 changes from the Hi state to the Lo state. The CPU 514 counts up a counter corresponding to the communication node that performed the transmission operation, and determines whether or not the count value exceeds a predetermined threshold value. The threshold value may be the same value regardless of the communication node, or may be a different value depending on the communication node. When the CPU 514 determines that the count value has exceeded a predetermined threshold value, the CPU 514 inputs a first abnormal wakeup signal to the first communication bus fixing circuit 506. On the other hand, when the CPU 514 determines that the count value of the number of transmission operations is equal to or less than a predetermined threshold, the CPU 514 executes processing corresponding to the transmission operation and shifts to the sleep state.

  When the first abnormal wakeup signal is input to the first communication bus fixing circuit 506, the first communication bus 10 is fixed to the dominant. Since the first communication bus 10 is fixed to a dominant state, the first communication node 100 and the second communication node 200 cannot receive data. When the first communication node 100 and the second communication node 200 are in a sleep-enabled state, the first communication node 100 and the second communication node 200 do not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or more from other communication nodes. It is determined that all the communication nodes including the second communication node 200 and the second communication node 200 can shift to the sleep state, and shift from the normal state to the sleep state.

  When the IG OFF signal is input to the CPU 514 and the sleep state is entered, the second communication bus 20 enters the bus sleep state.

  The CPU 514 determines whether a transmission operation has been performed for each communication node during a specified time. The CPU 514 detects the edge of the second communication bus 20 to identify the communication node that has performed the transmission operation. The CPU 514 counts up a counter corresponding to the communication node that performed the transmission operation, and determines whether or not the count value exceeds a predetermined threshold value. When the CPU 514 determines that the count value exceeds a predetermined threshold value, the CPU 514 inputs a second abnormal wakeup signal to the second communication bus fixing circuit 512. On the other hand, when the CPU 514 determines that the count value of the number of transmission operations is equal to or less than a predetermined threshold, the CPU 514 executes processing corresponding to the transmission operation and shifts to the sleep state.

  When the second abnormal wakeup signal is input to the second communication bus fixing circuit 512, the second communication bus 20 is fixed to the dominant. As the second communication bus 20 is fixed to the dominant, the third communication node 300 and the fourth communication node 400 cannot receive data. When the third communication node 300 and the fourth communication node 400 are in the sleep-enabled state, the third communication node 300 and the fourth communication node 400 do not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or longer from the other communication nodes. It is determined that all the communication nodes including the communication node 4 and the fourth communication node 400 can shift to the sleep state, and shift from the normal state to the sleep state.

  When the fifth communication node 500 is in a state where some control must be performed, or when the fifth communication node 500 controls an actuator or the like, the fifth communication node 500 is in a sleep disabled state. Judgment is made, and the sleep disable bit SLNG is set to active (in this embodiment, “1”) indicating that the sleep disable state is transmitted.

  Even if the fifth communication node 500 is in a sleep capable state, the fifth communication node 500 enters the sleep state if the sleep disable bit SLNG attached to the frame transmitted from another communication node is active. Does not migrate.

  Further, when the fifth communication node 500 does not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or more from another communication node, all the communication nodes including the fifth communication node 500 sleep. It is determined that the state can be changed, and the normal state is changed to the sleep state.

<Operation of communication system>
<Operation of First Communication Node 100>
5 and 6 show the operation of the first communication node 100. FIG. 5 and 6 can also be applied to the operations of the second communication node 200 to the fourth communication node 400.

  FIG. 5 shows the operation (part 1) of the first communication node 100.

  In step S502, the first communication node 100 determines whether or not it is in a state where it can shift to the sleep state. If it is determined that the first communication node 100 is not in the sleep disabled state, the first communication node 100 determines that the state can be shifted to the sleep state.

  If it is determined that the sleep state can be entered, the process returns to step S502.

  In step S504, if it is determined in step S502 that the first communication node 100 is not in a state capable of shifting to the sleep state, the first communication node 100 transmits a frame in which the sleep disable bit SLNG is set to active. By transmitting a frame in which the sleep disable bit SLNG is set to be active, it is possible to notify other communication nodes that the first communication node 100 cannot enter the sleep state.

  FIG. 6 shows the operation (part 2) of the first communication node 100.

  In step S602, the first communication node 100 determines whether or not it is in a state where it can shift to the sleep state. If it is determined that the first communication node 100 is not in a sleep-disabled state, the first communication node 100 determines that the state can be shifted to the sleep state.

  In step S604, if it is determined in step S602 that the first communication node 100 is ready to enter the sleep state, whether or not the first communication node 100 has received a frame in which the sleep disable bit SLNG is set active from another communication node is determined. judge. By determining whether or not a frame in which the sleep disable bit SLNG is set to active has been received from another communication node, it is possible to determine whether or not the other communication node cannot enter the sleep state.

  If it is determined that a frame in which the sleep disable bit SLNG is set to active has been received from another communication node, the process returns to step S602. When a frame in which the sleep disable bit SLNG is set to active is received from another communication node, the first communication node 100 receives data from another communication node that cannot shift to the sleep state. judge.

  In step S606, if the first communication node 100 determines in step S604 that it does not receive a frame in which the sleep disable bit SLNG is set to be active from another communication node, it determines whether or not a predetermined time has elapsed. . It is determined whether a predetermined time has passed without receiving a frame in which the sleep disable bit SLNG is set to be active from another communication node after entering the sleep state. Even when the communication state can be shifted to the sleeve state, when communication data is transmitted from another communication node, it is necessary to receive the communication data, so that it waits until a predetermined time elapses.

  If it is determined that the predetermined time has not elapsed without receiving a frame in which the sleep disable bit SLNG is set to be active from another communication node, the process returns to step S604.

  In step S608, when it is determined in step S606 that a predetermined time has passed without receiving a frame in which the sleep disable bit SLNG is set active from another communication node, the first communication node 100 shifts to the sleep state. To do. By determining whether or not a predetermined time has passed without receiving a frame in which the sleep disable bit SLNG is set to active from another communication node, it is possible to determine whether or not all communication nodes have shifted to the sleep state. .

  The first communication node 100 executes both the flowchart shown in FIG. 5 and the flowchart shown in FIG. 6 in parallel.

  FIG. 7 shows the operation of the fifth communication node 500. FIG. 7 shows an example in which communication is performed between the first communication node 100 connected to the first communication bus 10 and the second communication node 200. FIG. 7 can also be applied to the case where communication is performed between the third communication node 300 connected to the second communication bus 20 and the fourth communication node 400.

  In step S702, the fifth communication node 500 determines whether or not it is time to shift to the first sleep state after IG OFF. The fifth communication node 500 determines that the state can be shifted to the sleep state when the state that is not the sleep disabled state continues for a predetermined period after the IG is turned off. If it is determined that the sleep state cannot be entered, the process returns to step S702.

  In step S704, the fifth communication node 500 resets a counter, a timer, and the like when it is determined in step S702 that the state can be shifted to the sleep state. A new measurement is started by resetting the counter and timer.

  In step S <b> 706, the fifth communication node 500 wakes up by detecting the edge of the first communication bus 10. For example, when the first communication node 100 or the second communication node 200 transmits data, it sends an inverted signal to CANH and CANL. The fifth communication node 500 detects the edge of the first communication bus 10 caused by the inverted signal sent out by the first communication node 100 or the second communication node 200.

  In step S708, the fifth communication node 500 determines whether a specified time has elapsed. The fifth communication node 500 determines whether or not the timer value reset in step S704 has passed a specified time. By determining whether or not the timer value has passed the specified time, the number of communication operations can be counted by waking up during the specified time.

  In step S710, if the fifth communication node 500 determines that the specified time has elapsed in step S708, the fifth communication node 500 resets the counter and the timer, and returns to step S702.

  In step S712, the fifth communication node 500 determines the communication node that has transmitted the inverted signal to the first communication bus 10 when it is determined in step S708 that the specified time has not elapsed. The fifth communication node 500 determines the communication node that has transmitted the inverted signal based on the ID of the frame transmitted to the first communication bus 10.

  In step S714, the fifth communication node 500 increments the counter associated with the communication node determined in step S712.

  In step S716, the fifth communication node 500 determines whether or not the count value of the counter exceeds a predetermined threshold value. By determining whether or not the count value of the counter exceeds a predetermined threshold value, it is determined whether or not the communication node that transmitted the signal is abnormal.

  In step S718, when the fifth communication node 500 determines that the count value of the counter exceeds a predetermined threshold value, the fifth communication node 500 fixes the first communication bus 10 to dominant. If it is determined that the count value of the counter exceeds a predetermined threshold, it is determined that the communication node that transmitted the signal is abnormal. When it is determined that the communication node that has transmitted the signal is abnormal, the fact that the abnormality has been detected may be stored in the diagnosis. By storing the fact that an abnormality has been detected, it can be used when a failure occurs.

  When it is determined that the communication node that has transmitted the signal is abnormal, the first communication bus 10 is fixed to be dominant so that data cannot be transmitted from the communication node that has transmitted the signal.

  After the first communication bus 10 is fixed to the dominant, when the IG is turned on, the fixing to the dominant is released.

  In step S720, when the fifth communication node 500 determines that the count value of the counter does not exceed the predetermined threshold value, the fifth communication node 500 executes processing according to the transmission data from the first communication bus 10. When it is determined that the count value of the counter does not exceed the predetermined threshold, it is determined that the communication node that transmitted the signal is not abnormal.

  In step S722, the fifth communication node 500 determines whether it is time to shift to the sleep state. If it is determined that it is not time to enter the sleep state, the process returns to step S722.

  In step S724, if it is determined in step S722 that it is the timing to shift to the sleep state, the process shifts to the sleep state.

  A communication node that has shifted to the sleep state after being turned off may wake up when the communication bus is waked up by another communication node. When the user does not start the vehicle, the necessary information is transmitted and then the sleep state is entered again. However, it is assumed that the same communication node continues to wake up the communication bus due to an unintended software bug or a rare case that is not expected at the development stage. In this case, it is assumed that the battery is discharged in a short time when the other communication nodes are in the wake state, and the battery is raised by being left for several days.

  According to an embodiment of the communication system, the gateway device, when the communication node wakes up the communication bus during a predetermined period during IG OFF exceeds the predetermined number of times when the communication node wakes up the communication bus. Forced to the dominant side.

  The communication node connected to the gateway device via the communication bus is in the sleep state when it detects a dominant with the communication bus fixed to Lo level or when it does not receive a frame for which the sleep disable bit SLNG is active for a certain period of time. Migrate to For this reason, it is possible to prevent the power from being consumed and the battery from being increased by continuously wake-up the gateway device.

<Modification (Part 1)>
FIG. 8 shows a modification of the communication system.

  The communication system shown in FIG. 8 includes a sixth communication node 600 to a tenth communication node 1000 instead of the first communication node 100 to the fifth communication node 500 of the communication system shown in FIG. Is.

  The sixth communication node 600 to the tenth communication node 1000 are connected to the battery 50 through fuses 650, 750, 850, 950, and 1050, respectively.

<Sixth communication node 600>
FIG. 9 shows an embodiment of the sixth communication node 600. FIG. 9 mainly shows the hardware configuration of the sixth communication node 600. For the hardware configuration of the seventh communication node 700 to the ninth communication node 900, FIG. 9 or FIG. 2 may be applied.

  The sixth communication node 600 includes a communication transceiver 602, a communication circuit 604, a third communication bus fixing circuit 606, and a CPU 608.

  The communication transceiver 602 is connected to the first communication bus 10 and transmits communication data from the communication circuit 604 to the first communication bus 10 under the control of the communication driver, and communication data from the first communication bus 10. Is input to the communication circuit 604. When transmitting data, the communication transceiver 602 sends an inversion signal to CANH and CANL. When receiving data, the communication transceiver 602 determines whether the data on the first communication bus 10 is “1” or “0” from the voltage difference between CANH and CANL.

  The communication circuit 604 is connected to the communication transceiver 602 and performs serial communication with other communication nodes via the first communication bus 10. The communication circuit 604 transmits transmission data from the CPU 608 from the communication transceiver 602 and inputs reception data from the communication transceiver 602 to the CPU 608.

  The third communication bus fixing circuit 606 fixes the first communication bus 10 to the dominant side in accordance with a signal from the CPU 608 (hereinafter referred to as “third abnormal wakeup signal”). In the example illustrated in FIG. 9, the third communication bus fixing circuit 606 includes an npn transistor 6062, a first resistor 6064, and a second resistor 6066. The collector of the npn transistor 6062 is connected to the first communication bus 10, the emitter is grounded, and the base is connected to the first resistor 6064. Another terminal different from the terminal connected to the npn transistor 6062 of the first resistor 6064 is connected to the CPU 608. Further, the base and emitter of npn transistor 6062 are connected via a second resistor 6066. The third communication bus fixing circuit 606 may be configured with a configuration different from the example shown in FIG.

  The CPU 608 outputs a third abnormal wakeup signal to the third communication bus fixing circuit 606 in a predetermined case. By the third abnormal wakeup signal from the CPU 608, the npn transistor 6062 is turned on, and a current flows from the collector of the npn transistor 6062 toward the emitter. As a result of the current flowing from the collector of npn transistor 6062 toward the emitter, first communication bus 10 is fixed to the dominant.

  The CPU 608 is connected to the communication circuit 604 and executes communication processing executed by the communication circuit 604 and processing for controlling the sixth communication node 600. The CPU 608 is supplied with battery power (+ B power) and an IG signal.

  The CPU 608 controls the operation state of the sixth communication node 600. The operation state of the sixth communication node 600 is a normal state when the CPU 608 is operating in the normal mode. When the CPU 608 enters the sleep state, power consumption associated with the operation of the CPU 608 is reduced and the communication circuit 604 is connected. Since the power supply is interrupted, the sleep state, which is a state of low power consumption, is entered.

  The CPU 608 includes a timer that measures a specified time and one or more counters that count the number of transmission operations. Each counter is associated with a communication node. The CPU 608 performs the following processing after the IG OFF signal is input and the sleep state is entered until the IG ON signal is input.

  When the IG OFF signal is input to the CPU 608 and the sleep state is entered, the first communication bus 10 enters the bus sleep state.

  The CPU 608 determines whether a transmission operation has been performed by waking up for each communication node during a specified time. The CPU 608 detects the edge of the first communication bus 10 to identify the communication node that has performed the transmission operation by waking up. The CPU 608 counts up a counter corresponding to the communication node that has performed the transmission operation, and determines whether or not the count value exceeds a predetermined threshold value. When the CPU 608 determines that the count value exceeds a predetermined threshold, the CPU 608 inputs a third abnormal wakeup signal to the third communication bus fixing circuit 606. On the other hand, when the CPU 608 determines that the count value of the number of transmission operations is equal to or less than a predetermined threshold value, the CPU 608 executes processing corresponding to the transmission operation and shifts to the sleep state.

  When the third abnormal wakeup signal is input to the third communication bus fixing circuit 606, the first communication bus 10 is fixed to the dominant. Since the first communication bus 10 is fixed to the dominant state, the seventh communication node 700 and the tenth communication node 1000 cannot transmit data to the first communication bus 10. When the seventh communication node 700 and the tenth communication node 1000 are in the sleep capable state, the other communication nodes send frames in which the sleep disable bit SLNG is active via the first communication bus 10 for a predetermined time or more. Since it is not continuously received, it is determined that all the communication nodes including the seventh communication node 700 and the tenth communication node 1000 can shift to the sleep state, and shift from the normal state to the sleep state.

  The signal frame structure shown in FIG. 3 can be applied to the frame structure of signals transmitted and received by the sixth communication node 600.

  The data field of the transmission signal from the sixth communication node 600 is accompanied by a sleep disable bit SLNG as notification information for notifying other communication nodes that the sixth communication node 600 is in a sleep disabled state. There is also a case.

  When the sixth communication node 600 is in a state where some control must be performed, or when the sixth communication node 600 controls an actuator or the like, the sixth communication node 600 is in a sleep disabled state. Judgment is made, and the sleep disable bit SLNG is set to active (in this embodiment, “1”) indicating that the sleep disable state is transmitted.

  Even if the sixth communication node 600 is in the sleep capable state, the sixth communication node 600 goes to the sleep state if the sleep disable bit SLNG attached to the frame transmitted from another communication node is active. Does not migrate.

  Further, when the sixth communication node 600 does not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or more from another communication node, all the communication nodes including the sixth communication node 600 are in the sleep state. It is determined that the state can be changed, and the normal state is changed to the sleep state.

<Tenth communication node 1000>
FIG. 10 shows an embodiment of the tenth communication node 1000. FIG. 10 mainly shows the hardware configuration of the tenth communication node 1000.

  The tenth communication node 1000 includes a first communication transceiver 1002, a first communication circuit 1004, a second communication transceiver 1008, a second communication circuit 1010, and a CPU 1014.

  The first communication transceiver 1002 is connected to the first communication bus 10 and transmits transmission data from the first communication circuit 1004 to the first communication bus 10 under the control of the communication driver. Received data from the bus 10 is input to the first communication circuit 1004. When transmitting data, the first communication transceiver 1002 sends an inverted signal to CANH and CANL. When receiving data, the first communication transceiver 1002 determines whether the data on the first communication bus 10 is “1” or “0” from the voltage difference between CANH and CANL. .

  The first communication circuit 1004 is connected to the first communication transceiver 1002 and performs serial communication with other communication nodes via the first communication bus 10. The first communication circuit 1004 transmits the transmission data from the CPU 1014 from the first communication transceiver 1002 and inputs the reception data from the first communication transceiver 1002 to the CPU 1014.

  The second communication transceiver 1008 is connected to the second communication bus 20 and transmits communication data from the second communication circuit 1010 to the second communication bus 20 under the control of the communication driver. Communication data from the bus 20 is received and input to the second communication circuit 1010. When transmitting data, the second communication transceiver 1008 sends an inverted signal to CANH and CANL. When receiving data, the second communication transceiver 1008 determines whether the data on the second communication bus 20 is “1” or “0” from the voltage difference between CANH and CANL. .

  The second communication circuit 1010 is connected to the second communication transceiver 1008 and performs serial communication with other communication nodes via the second communication bus 20. The second communication circuit 1010 transmits communication data from the CPU 1014 from the second communication transceiver 1008 and inputs communication data from the second communication transceiver 1008 to the CPU 1014.

  The CPU 1014 is connected to the first communication circuit 1004 and the second communication circuit 1010, and controls communication processing executed by the first communication circuit 1004 and the second communication circuit 1010 and the tenth communication node 1000. Execute the process. The CPU 1014 is supplied with battery power (+ B power) and an IG signal.

  The CPU 1014 controls the operation state of the tenth communication node 1000. The operating state of the tenth communication node 1000 becomes a normal state when the CPU 1014 is operating in the normal mode. When the CPU 1014 enters the sleep state, power consumption associated with the operation of the CPU 1014 is reduced and the first communication is performed. Since the power supply to the circuit 1004 and the second communication circuit 1010 is cut off, the sleep state in which the power consumption is low is entered.

  The tenth communication node 1000 transmits and receives signals between the sixth communication node 600 and the ninth communication node 900.

  When the tenth communication node 1000 is in a state where some control must be performed, or when the tenth communication node 1000 controls an actuator or the like, the tenth communication node 1000 is in a sleep disabled state. Judgment is made, and the sleep disable bit SLNG is set to active (in this embodiment, “1”) indicating that the sleep disable state is transmitted.

  Even if the tenth communication node 1000 is in a sleep capable state, the tenth communication node 1000 enters the sleep state if the sleep disable bit SLNG attached to the frame transmitted from another communication node is active. Does not migrate.

  Further, when the tenth communication node 1000 does not continuously receive a frame in which the sleep disable bit SLNG is active for a predetermined time or more from another communication node, all the communication nodes including the tenth communication node 1000 sleep. It is determined that the state can be changed, and the normal state is changed to the sleep state.

<Operation of communication system>
<Operation of Sixth Communication Node 600>
The flowchart described with reference to FIG. 7 can be applied to the operation of the sixth communication node 600.

<Operation of Tenth Communication Node 1000>
The operations described with reference to FIGS. 5 and 6 can be applied to the operation of the tenth communication node 1000.

  However, in step S504, the tenth communication node 1000 transmits a frame in which the sleep disable bit SLNG is set to active to the first communication bus 10 and the second communication bus 20.

  According to one modification of the communication system, the communication node, in a predetermined period during IG OFF, when the number of times that the communication node or gateway device wakes up by wake up the communication bus exceeds a predetermined number of times, Force the communication bus to the dominant side.

  The gateway device connected to the communication node via the communication bus, the communication node detects a dominant in which the communication bus is fixed at the Lo level, or does not receive a frame in which the sleep disable bit SLNG is active for a certain period of time. Enter sleep mode. For this reason, it is possible to prevent the battery from being consumed due to the power consumption due to the gateway device and the communication node continuing to wake up.

<Modification (Part 2)>
One modification of the communication system is configured by combining the fifth communication node 500 according to the above-described embodiment and the sixth communication node according to the above-described modification.

  In the communication system according to the above-described embodiment, the fifth communication node 500 can detect an abnormality of another communication node, but cannot detect an abnormality of the fifth communication node 500 itself.

  Further, in the communication system according to the above-described modification, the sixth communication node 600 can detect an abnormality of another communication node, but cannot detect an abnormality of the sixth communication node 600 itself.

  Therefore, by configuring the communication system by combining the fifth communication node 500 and the sixth communication node 600, the fifth communication node 500 detects an abnormality in the sixth communication node 600, and the sixth communication node The node 600 can detect an abnormality in the fifth communication node 500.

  Although the present invention has been described above with reference to specific embodiments and modifications, each embodiment and modification is merely illustrative, and those skilled in the art will recognize various modifications, modifications, alternatives, and substitutions. You will understand examples. For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be implemented in hardware, software, or a combination thereof. The present invention is not limited to the above-described embodiments, and various variations, modifications, alternatives, substitutions, and the like are included without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 50 Battery 10 1st communication bus 20 2nd communication bus 100 1st communication node 102 Communication transceiver 104 Communication circuit 106 CPU
150 fuse 200 second communication node 250 fuse 300 third communication node 350 fuse 400 fourth communication node 450 fuse 500 fifth communication node 502 first communication transceiver 504 first communication circuit 506 first communication bus Fixing circuit 508 Second communication transceiver 510 Second communication circuit 512 Second communication bus fixing circuit 514 CPU
550 Fuse 600 Sixth communication node 602 Communication transceiver 604 Communication circuit 606 Third communication bus fixing circuit 608 CPU
650 fuse 700 seventh communication node 750 fuse 800 eighth communication node 850 fuse 900 ninth communication node 950 fuse 1000 tenth communication node 1002 first communication transceiver 1004 first communication circuit 1008 second communication transceiver 1010 Second communication circuit 1050 Fuse 1014 CPU

Claims (10)

A communication node mounted on a vehicle and connected to a plurality of communication buses, and a gateway device connected between the plurality of communication buses and relaying communication between the communication nodes connected to different communication buses A communication system comprising:
The gateway device is
A receiving unit for receiving data transmitted by a communication node connected to one communication bus of the plurality of communication buses;
A communication node that transmits data from the one communication bus is specified, and a count value of a transmission counter that counts the number of transmissions of data associated with the communication node that transmits the data is increased. A control unit that disables data communication through the one communication bus when the count value is equal to or greater than a threshold value,
The control unit specifies a communication node that transmits data received by the receiving unit after the ignition of the vehicle is turned off and the gateway device enters a sleep state.
The communication node connected to the one communication bus is:
A communication unit for transmitting data to the one communication bus and receiving data from the one communication bus;
A control unit that determines that the local communication node can enter the sleep state and that does not receive data from another communication node for a predetermined period of time; A communication system mounted on a vehicle and having a plurality of communication nodes connected to a communication bus,
One communication node of the plurality of communication nodes is:
A receiving unit for receiving data transmitted by another communication node other than one communication node of the plurality of communication nodes;
When the other communication node is specified, the count value of the transmission number counter that counts the number of transmissions of data associated with the other communication node is increased, and the count value of the transmission number counter is equal to or greater than a threshold value A control unit for disabling data communication via the communication bus,
The control unit specifies a communication node that transmits data received by the reception unit after the ignition of the vehicle is turned off and the communication node shifts to a sleep state,
The other communication node is:
A communication unit for transmitting data to the communication bus and receiving data from the communication bus;
A control unit that determines that the local communication node can enter the sleep state and that does not receive data from another communication node for a predetermined period of time; A gateway device mounted on a vehicle, connected between a plurality of communication buses, and relaying communication between communication nodes connected to different communication buses,
A receiving unit for receiving data transmitted by a communication node connected to one communication bus of the plurality of communication buses;
A communication node that transmits data from the one communication bus is specified, and a count value of a transmission counter that counts the number of transmissions of data associated with the communication node that transmits the data is increased. A control unit that disables data communication through the one communication bus when the count value is equal to or greater than a threshold value,
The said control part is a gateway apparatus which specifies the communication node which transmits the data received by the said receiving part, after the ignition of the said vehicle is turned off and the self-gateway apparatus transfers to a sleep state.   The gateway device according to claim 3, wherein the control unit fixes the communication bus to a dominant voltage when the count value is equal to or greater than a threshold value.   The gateway device according to claim 3 or 4, wherein when the ignition of the vehicle is turned on, the control unit enables data communication through the one communication bus. A communication node mounted on a vehicle and connected to a communication bus.
A receiving unit for receiving data transmitted by a communication node other than one of the plurality of communication nodes connected to the communication bus;
When the other communication node is specified, the count value of the transmission number counter that counts the number of transmissions of data associated with the other communication node is increased, and the count value of the transmission number counter is equal to or greater than a threshold value A control unit for disabling data communication via the communication bus,
The said control part is a communication node which specifies the communication node which transmits the data received by the said receiving part, after the ignition of the said vehicle is turned off and a self-communication node transfers to a sleep state.   The communication node according to claim 6, wherein the control unit fixes the communication bus to a dominant-side voltage when the count value is equal to or greater than a threshold value.   The communication node according to claim 6 or 7, wherein when the ignition of the vehicle is turned on, the control unit enables data communication through the communication bus. A communication control method in a gateway device that is mounted on a vehicle and connected between a plurality of communication buses and relays communication between communication nodes connected to different communication buses,
When the ignition of the vehicle is turned off and the gateway device shifts to a sleep state, it receives data transmitted by a communication node connected to one communication bus of the plurality of communication buses,
Identifying a communication node that transmits the data;
Increase the count value of the transmission number counter that counts the number of transmissions of data associated with the communication node that transmits the data,
A communication control method for disabling data communication through the one communication bus when a count value of the transmission number counter is equal to or greater than a threshold value. A communication control method in one communication node of a plurality of communication nodes mounted on a vehicle and connected to a communication bus,
When the ignition of the vehicle is turned off and the own communication node shifts to a sleep state, it is transmitted by a communication node other than one of the plurality of communication nodes connected to the communication bus. Receive data,
Identifying the other communication node;
Increase the count value of the transmission number counter that counts the number of transmissions of data associated with the other communication node,
A communication control method for disabling data communication via the communication bus when a count value of the transmission number counter is equal to or greater than a threshold value.

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