JP2008278403A - Monitoring apparatus and method of network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication apparatus in which even in a case where abnormality occurs on a communication bus line, a node wherein abnormality does not occur can be continuously operated and in a case where abnormality occurs in a node connected to the communication bus line, only the relevant node can be disconnected without disconnecting the communication bus line. <P>SOLUTION: The present invention relates to a monitoring apparatus 5 for monitoring a communication line 3 to which a plurality of nodes 4 are connected, including: a plurality of switching means for dividing the communication line 3 into two or more communication lines 3; and a control means in which, when abnormality occurs on the communication line 3, the switching means are controlled to specify a position at which the abnormality occurs, and the switching means are controlled to separate the communication line 3 to which the specified position at which the abnormality occurs, belongs from the other communication lines 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication device configured such that a plurality of nodes are connected to a communication bus line and each node can communicate with each other via the communication bus line.

  Generally, in a control system that controls a vehicle or the like, a communication network is constructed by connecting a plurality of nodes (electronic control units in the case of a vehicle) to each other via a communication line.

  Conventionally, in the communication network, a short circuit of the communication line due to the occurrence of an abnormality in a circuit provided in any node on the communication network or a short circuit due to contact with another line of the communication line itself has occurred. Then, all communications on the communication network were interrupted, and the entire control system was unusable.

  An example of the occurrence of an abnormality in the circuit is that the circuit is grounded or shorted to another line due to impact caused by a collision with an obstacle such as a vehicle or submergence of a vehicle due to heavy rain, etc. There is.

  In addition, as an example of a short circuit due to contact with the other line of the communication line itself, due to the cause such as the communication line being pinched by the door of the vehicle, the wire of the communication line is stripped off, There is a short circuit due to the wire coming into contact with another line.

In order to solve the above-described problem, Patent Document 1 discloses a determination circuit that determines an abnormal state of a communication line including a transmission power line and a transmission signal line, and a time period during which the communication line connected to the determination circuit is in an abnormal state. A detection device that performs detection, and a connection / disconnection mechanism that connects / disconnects the transmission power line and the transmission signal line by an output from the detection device that an abnormal state of the communication line continues for a predetermined time or more. In the communication line, a signal transmission device has been proposed that is capable of separating a portion in an abnormal state from a portion in a normal state.
Japanese Patent Laid-Open No. 2-10935

  However, in Patent Document 1, when the communication line is disconnected in the signal transmission device, all the nodes connected to the communication line on the disconnected side as being in an abnormal state are not disconnected as being in a normal state. It becomes impossible to communicate with the communication line on the side. That is, when an abnormality occurs in a certain node, only that node cannot be disconnected from the communication line.

  Further, in Patent Document 1, even if an abnormality occurs only at one of the nodes, the communication line itself is disconnected and all the nodes become inoperable. When an abnormality occurs in the unit), the engine cannot be stopped safely by continuing the operation only with the remaining electronic control units.

  In view of the above-described conventional problems, an object of the present invention is to continue operation of a node in which no abnormality has occurred even when an abnormality occurs in the communication bus line, and is connected to the communication bus line. The present invention is to provide a communication device capable of disconnecting only the node without disconnecting the communication bus line when an abnormality occurs in the node.

  In order to achieve the above object, a first characteristic configuration of the monitoring device according to the present invention is a monitoring device 5 for monitoring a communication line to which a plurality of nodes are connected, and the communication line is divided into two or more communication lines. A plurality of switching means to be divided, and when the abnormality occurs in the communication line, the switching means is controlled to identify an abnormality occurrence location, and the communication line to which the abnormality occurrence location identified by controlling the switching means belongs The control means for separating from the communication line is provided.

  According to the above-described configuration, when an abnormality in any one of the nodes or an abnormality in the communication line occurs, the monitoring device can detect only the node in which the abnormality has occurred or the communication line. Only the part where the abnormality has occurred is separated from the communication line.

  The second characteristic configuration is a monitoring device that monitors a communication line to which a plurality of nodes are connected, and branches the communication line from a first communication line to a second communication line. A plurality of switching means for dividing the line and the second communication line, and a control means for separating the node when an abnormality occurs in the node connected to the second communication line.

  According to the configuration described above, the monitoring device disconnects only the second communication line and the node connected to the second communication line where the abnormality has occurred from the first communication line.

  As described above, according to the present invention, even when an abnormality occurs in the communication bus line, the operation of the node in which no abnormality has occurred can be continued, and the node connected to the communication bus line has an abnormality. When this occurs, it is possible to provide a communication device that can disconnect only the node without disconnecting the communication bus line.

  Hereinafter, an embodiment in which a communication device according to the present invention is applied to a vehicle control system as a network system in which a plurality of electronic control units cooperate to control a predetermined control target will be described.

  As shown in FIG. 1, the vehicle control system 1 includes a communication device 2, and the communication device 2 connects a plurality of nodes 4 to a communication bus line 3 as a communication line, and each node 4 is connected to the communication bus line 3. Communication with each other via the communication bus line 3 is possible.

  The node 4 is an electronic control that controls each part of the vehicle or performs input processing from a sensor (for example, a yaw G sensor that senses a skid of a brake or a steering angle sensor that detects a steering angle of a steering wheel). The HV-ECU 41 is configured by a unit (hereinafter referred to as an ECU), for example, and performs hybrid control for distributing engine control, travel control amount to engine control, electric motor control, and brake control according to vehicle conditions and user requests. An EPS-ECU 42 (Electric Power Steering ECU) that controls electric power steering, a gateway ECU 43 that relays data communication between networks, an ECB-ECU 44 (Electric Control Break ECU) that controls electric brakes, It is composed of a back guide monitor ECU45 for controlling the rectangular monitor.

  Each of the ECUs 4 includes a communication interface circuit for enabling transmission and reception of communication data with other ECUs 4, a ROM for storing a control program, and a RAM as a working area used for data processing. The CPU is connected to the input / output interface circuit, the ROM, and the RAM via an internal bus and executes the control program, and is repeatedly executed by the occurrence of a preset cycle or event. A predetermined function is implemented based on the control program and the built-in data.

  The communication bus line 3 only needs to be capable of appropriately transmitting and receiving data between the plurality of ECUs 4. In the present embodiment, the communication bus line 3 is a CAN (Controller Area Network) bus generally used in a vehicle, that is, a pair of signal lines (for example, as shown in FIGS. 1 and 2, a CANH line). 31 and the CANL line 32) will be described with respect to the case where the communication bus line is constituted by a differential signal system that transmits and receives data by transmitting signals of opposite phases.

  When an abnormality occurs in the communication bus line 3, the communication device 2 divides the plurality of nodes 4 (ECU 4) into groups with the abnormality occurrence point as a boundary, and performs communication within each group of the communication bus line 3. The bus monitoring unit 5 is configured to enable the above. That is, the bus monitoring unit 5 is configured as a monitoring device that monitors the communication bus line 3 to which a plurality of nodes 4 are connected.

  The bus monitoring unit 5 is configured such that the communication bus line 3 is covered with an insulating coating, and a control circuit as a control unit and a switch circuit as a switching unit described below are provided inside the coating unit. It is configured with.

  More specifically, the bus monitoring unit 5 controls a plurality of switch circuits that divide the communication bus line 3 into two or more communication bus lines 3 and the switch circuit when an abnormality occurs in the communication bus line 3. Thus, it is configured to include a control means for specifying an abnormality occurrence location and controlling the switch circuit to separate a communication line to which the identified abnormality occurrence location belongs from other communication lines.

  Specifically, as shown in FIG. 1, the bus monitoring unit 5 is provided at a connection portion between the main line 33 and the branch line 34 of the communication bus line 3, and as shown in FIG. A control circuit 52 that controls the switching circuit 53 based on the voltage of the line 3 to switch the short circuit of the communication bus line 3 to the main line 33 and the connection to the termination resistors R1 and R2 as termination circuits; The switch circuit 53 is disposed on the bus line 3 and is controlled to be switched by the control circuit 52. A terminator is a resistor that is inserted to prevent noise from appearing on the signal due to reflection due to impedance mismatch, and is an important configuration for improving the reliability of data transmission in a network such as CAN. is there.

  The switch circuit 53 includes two switches 531 for disconnecting the main line 33 of the communication bus line 3 on one side (for example, the right side) from the other side (for example, the left side) as viewed from the bus monitoring unit 5; When the main line 33 is disconnected by the switch 531, a termination resistor R1 that replaces the termination resistance provided on the disconnected main line 33 and the other side (for example, the left side) of the bus monitoring unit 5 Two switches 532 for disconnecting the main line 33 of the communication bus line 3 from one side (for example, the right side) and the main line 33 that was disconnected when the main line 33 was disconnected by the switch 532 were provided. And a termination resistor R2 that replaces the termination resistor.

  In the bus monitoring unit 5, the termination resistors R1 and R2 respectively provided in the switch circuit 53 are shared by the two switch circuits 53 as a seed end resistor R12 as shown in FIG. 4A. It may be configured.

  The control circuit 52 is configured by an integrated circuit such as an ASIC (Application Specific Integrated Circuit), and receives power supply from an external power source 60 that is converted into a predetermined voltage by using power from a vehicle battery via a regulator. The predetermined functions described below are realized. Note that the control circuit 52 is configured to be able to switch power supply between the external power supply 60 and the bus monitoring unit 5 or by turning on / off a power supply switch 61 provided in the external power supply 60. ing.

  Hereinafter, predetermined functions of the control circuit 52 will be described. The control circuit 52 inputs the voltage level of CANH, which is a signal on the CANH line 31, and the voltage level of CANL, which is a signal on the CANL line 32, at a constant cycle, and the input voltage level is outside a preset proper range. If it exists or if the state outside the appropriate range continues for a predetermined time or more, it is determined that an abnormality such as disconnection has occurred in the communication bus line 3.

  For example, the CAN bus is a differential signal system and is configured by a two-wire line. Of these two-wire lines, a signal to be transmitted is transmitted as a binary signal to one line with a positive DC voltage. Further, a signal to be transmitted is transmitted as a binary signal to the other line with a negative DC voltage. As described above, if the signal is discriminated based on the polarity instead of the voltage level, the signal can be reliably transmitted without being affected by noise. In addition, there are two voltage levels in the CAN bus, dominant and recessive. Transmit and receive signals have one of these voltage levels, and dominant level signals are not modified by recessive level signals, but recessive level signals are modified by dominant level signals. The In other words, the dominant level signal has a higher priority than the recessive signal. In the normal state, the vehicle control system 1 has a recessive level where the CANH voltage level and the CANL voltage level are both 2.5 (V) and the difference is 0 (V), and the dominant level is the CANH voltage level. Is 3.5 (V), the voltage level of CANL is 1.5 (V), and the difference is 2.0 (V), the voltage level of at least one of the CANH line 31 and the CANL line 32 is caused by disconnection. When the voltage becomes approximately 0 (V) due to grounding or the like, the control circuit 52 determines that an abnormality has occurred in the communication bus line 3.

  That is, when the communication bus line 3 is a differential signal type bus line, the bus monitoring unit 5 is provided with termination resistors R1 and R2 as termination circuits at the node 4 connected to the communication bus line 3. The terminal resistors R1 and R2 of the communication bus line 3 are switched.

  When the control circuit 52 determines that an abnormality such as disconnection has occurred in the communication bus line 3, the control circuit 52 switches and controls the switch circuit 53, thereby generating an abnormality in the communication bus line 3 in which the abnormality has occurred. Disconnect from the communication bus line 3 that is not connected. More specifically, when an abnormality occurs in the communication bus line 3, the plurality of control circuits 52 on the communication bus line 3 have their own switches 531 so that the communication bus line 3 is divided into predetermined small groups. 532 is controlled. Thereafter, each of the control circuits 52 executes the abnormality detection process again. The group in which the short has occurred is identified from the result of the abnormality detection process. The control circuit 52 controls the switches 531 and 532 so as to be configured into an abnormality occurrence group and a group in which no abnormality has occurred so as to isolate the specified abnormality occurrence group.

  As another example, when an abnormality occurs in the communication bus line 3, each of the control circuits 52 controls the switches 531 and 532 to switch the communication bus line 3 to termination resistors R1 and R2 one side at a time. There is a method of determining which side of the communication bus line 3 is abnormal as viewed from the control circuit 52. More specifically, when the control circuit 52 determines that an abnormality such as disconnection has occurred in the communication bus line 3, only one of the switch 531 and the switch 532 (for example, the switch 532) is the main line 33. The connection is switched from the short circuit to the terminal resistor R2.

  In this state, the control circuit 52 determines whether or not the input voltage level has returned to a normal level, and if the voltage level has returned to a normal level, the abnormality has been resolved. The current state (that is, the state in which the switch 532 is switched to the connection to the termination resistor R2 and the switch 531 is switched to the short circuit to the main line 33) is maintained.

  On the other hand, if the input voltage level does not return to a normal level, the control circuit 52 determines that the abnormality has not been resolved, switches the switch 532 to a short circuit to the main line 33, and switches the switch 531. Is switched to the connection to the terminating resistor R1.

  In this state, the control circuit 52 determines whether or not the input voltage level has returned to a normal level, and if the voltage level has returned to a normal level, the abnormality has been resolved. The current state (that is, the state where the switch 531 is switched to the connection to the termination resistor R1 and the switch 532 is switched to the short circuit to the main line 33) is maintained.

  On the other hand, when the input voltage level does not return to a normal level, the control circuit 52 determines that the abnormality has not been resolved, and switches the switch 532 to connection to the termination resistor R2. In this case, the bus monitoring unit 5 is disconnected from the main line 33 of the communication bus line 3 on both sides thereof.

  The control circuit 52 determines that an abnormality such as disconnection has occurred in the communication bus line 3, and switches the switches 531 and 532 from short-circuiting to the main line 33 to connecting to the terminating resistors R1 and R2, respectively. Whenever a predetermined time elapses, the switches 531 and 532 are again switched to short circuit to the main line 33 to detect the voltage level of the communication bus line 3. If the detected voltage level is within the proper range, the control circuit 52 maintains that state (the state switched to the short circuit to the main line 33), and if it is out of the proper range, switches to the terminal resistor again. . Note that switching to the short circuit is performed a predetermined number of times.

  Accordingly, even when all of the switches provided in the plurality of bus monitoring units 5 are switched to the connection to the termination resistor by the control circuit 52 when an abnormality occurs, the connection to the main line 33 is performed every time a predetermined time elapses. Switch to short circuit. At this time, the switch 531 or 532 on the abnormality occurrence location side of the bus monitoring unit 5 located closest to the communication bus line 3 where the abnormality has occurred is switched to a short circuit to the main line 33 without the abnormality being resolved. (To be precise, it is switched to the short circuit to the main line 33 a predetermined number of times, but it is switched to the connection to the termination resistor again), so that the bus that is at the closest position on both sides of the place where the abnormality finally occurred Only the switch on the abnormality occurrence side of the monitoring unit 5 is connected to the termination resistor, and the other switches are restored to the short circuit to the main line 33 from the state connected to the termination resistor.

  The bus monitoring unit 5 divides the vehicle control system 1 into a plurality of groups by switching control of the switch circuit 53 by the control circuit 52 described above.

  For example, in the vehicle control system 1 shown in FIG. 1, when the main line 33 of the communication bus line 3 is disconnected at the point A, the bus monitoring unit 5A and the bus monitoring unit 5B connect the communication bus line 3 including the point A to the A By separating from the communication bus line 3 that does not include a point, the vehicle control system 1 is divided into two groups as shown in FIG.

  In this case, one group constitutes the vehicle control system 11 including the HV-ECU 41, the EPS-ECU 42, and the gateway ECU 43, and the other group includes the ECB-ECU 44, the back guide monitor ECU 45, and the The vehicle control system 12 including the steering angle detection unit 47 is configured.

  Each vehicle control system 11, 12 continues to operate as two independent vehicle control systems 1.

  According to the above-described configuration, even if the communication bus line 3 is separated and divided, a unique vehicle control system 1 is constructed for each group of divided ECUs 4 and each vehicle control system 1 continues to operate independently. Therefore, it is possible to avoid a situation in which the vehicle control system suddenly stops during traveling of the vehicle or the like.

  For example, even if the engine is stopped due to an abnormality in the HV-ECU 41, the operation of the light ECU that controls the lighting continues, so that the user can I can know the situation. Further, even when the engine is stopped due to an abnormality in the HV-ECU 41, the operation of the door ECU for controlling the opening / closing of the door, the on / off of the key lock, etc. continues, so that the user ignites the engine. You can try to escape from the vehicle before it explodes. Furthermore, even when the electric power steering cannot be operated due to an abnormality in the EPS-ECU 42, the vehicle can be stopped by operating the brake.

  Further, according to the above-described configuration, even if the termination resistor is required for the ECU 4 or the communication bus line 3 that has not been terminated until then, the bus monitoring unit 5 is disconnected. By switching to a state in which the termination resistor is connected, it is possible to avoid a state in which the termination resistor is not provided in the ECU 4 or the communication bus line 3 that requires the termination resistor.

  Here, in the above-described configuration, after the vehicle control system 1 is divided into a plurality of groups, control data from the ECU 4 included in another vehicle control system 1 is required when a certain vehicle control system 1 operates. In some cases, the control data cannot be received, which may hinder the normal operation of the vehicle control system 1.

  Therefore, in the communication device 2, the connection positions of the ECUs 4 are set along the communication bus line 3 so that highly relevant ECUs 4 among the plurality of ECUs 4 are grouped.

  For example, in order to increase the possibility that the HV-ECU 41, the EPS-ECU 42, the ECB-ECU 44, etc., which are ECUs related to braking of the vehicle, become the same group at the time of division, they are connected to each other in close proximity, The airbag ECU that controls the bag and the various sensors that the airbag ECU refers to are connected to each other in close proximity to increase the possibility that they will be in the same group when divided.

  This avoids a situation in which the operation of the brake becomes impossible because the ECB-ECU 42 does not exist in the same group even though the engine is driven by the control of the HV-ECU 41. In addition, since at least one of the various sensors does not exist in the group to which the airbag ECU belongs at the time of group division, a situation in which the airbag does not operate can be avoided.

  That is, according to the above-described configuration, even when the communication bus line 3 is disconnected and the ECU 4 is divided, it is highly possible that the highly relevant ECU 4 belongs to the same group. The possibility of stopping the operation of the group due to the absence of the ECU 4 in the own group can be reduced.

  In addition, the communication device 2 is configured to include a return control unit that joins the plurality of divided groups to the original state when the cause of the abnormality of the communication bus line 3 where the abnormality has occurred is resolved.

  More specifically, the return control unit is realized by adding the following functions to the control circuit 52.

  That is, the control circuit 52 includes the return control unit, so that all the power supply switches 61 are once switched off at the start of maintenance of the communication device 2 and then the power supply switch 61 at the end of the maintenance. When the switch is switched from off to on, the initial state, that is, both the switches 531 and 532 return to the state shorted to the main line 33 of the communication bus line 3.

  According to the above configuration, when the vehicle control system 1 is divided into a plurality of groups by disconnecting the communication bus line 3 or the like, the user temporarily stops the power supply to the vehicle control system 1 and the communication When the power supply to the bus monitoring unit 5 is re-supplied after performing maintenance such as a return operation from the disconnected state of the bus line 3, the return control unit automatically returns the switch circuit 53 to the initial state. However, it is not necessary to manually return the switch circuit 53 to the initial state.

  Hereinafter, the disconnection of the communication bus line 3 by the communication device 2 and the return of the communication bus line 3 will be described based on the flowchart shown in FIG.

  When the bus monitoring unit 5 determines that an abnormality such as disconnection has occurred in the communication bus line 3 based on the voltage of the communication bus line 3 in a state where power is supplied (SA1), the communication bus line 3 The part determined to be abnormal is separated from the other parts (SA3).

  In step SA1, if the bus monitoring unit 5 is not powered (SA1), and the communication bus line 3 has been disconnected in step SA3 in the past (SA4), the user has been disconnected. Maintenance such as line connection processing is performed (SA5).

  When the user switches the power supply from OFF to ON after the maintenance is completed (SA6), the return control unit switches the switch circuit 53 to the initial state so that the disconnected communication bus line 3 is not disconnected. Switch (SA7).

  Hereinafter, another embodiment will be described. In the above-described embodiment, when an abnormality occurs in the communication bus line 3, the communication device 2 divides the plurality of nodes 4 into groups with the abnormality occurrence point as a boundary, and within each group of the communication bus line 3. Although the configuration including the bus monitoring unit 5 that enables communication has been described, the communication device 2 is configured in addition to or in place of the above-described embodiment as illustrated in FIG. In addition, the bus monitoring unit 5 branches the communication bus line 3 from the first communication bus line 33 as the first communication line as the main line to the second communication bus line 34 as the second communication line as the branch line. The bus monitoring unit 5 may be configured to disconnect the node 4 when an abnormality occurs in the node 4 connected to the second communication bus line 34.

  That is, the bus monitoring unit 5 monitors the communication bus line 3 to which a plurality of nodes 4 are connected, branches the communication bus line 3 from the first communication bus line 33 to the second communication bus line 34, When an abnormality occurs in the plurality of switch circuits 53 that divide the first communication bus line 33 and the second communication bus line 34 and the node 4 connected to the second communication bus line 34, the node 4 is provided with a control circuit 52 for separating 4.

  This will be described in detail below. In the vehicle control system 1 including the communication device 2 according to the present embodiment, as shown in FIG. 1, the first communication bus line 33 branches to the second communication bus line 34 in the bus monitoring unit 5, The branched second communication bus line 34 is connected to each node 4.

  Then, as shown in FIG. 6A, the bus monitoring unit 5 sets the voltage level of the second communication bus line 34 and the value of a sensor that detects an abnormality of the node 4 such as the submergence sensor 41. Based on the control circuit 52, the control circuit 52 for controlling the connection between the short-circuit and the open-circuit of the second communication bus line 34 by controlling the switch circuit 53, and the control circuit arranged on the second communication bus line 34. And a switch circuit 53 including two switches whose state is controlled to be switched by the switch 52.

  Specifically, the control circuit 52 determines whether the voltage level of CANH or CANL of the second communication bus line 34 is within a preset appropriate value range, and the node 4 When the submergence is detected, the switch circuit 53 is turned off.

  Here, the submergence sensor 41 is a sensor that is provided in the node 4 and detects that the node 4 is submerged. The submergence sensor 41 includes counter electrodes. If water adheres between the counter electrodes, the submergence sensor 41 includes water. A known sensor is used in which an electric current is generated between both electrodes due to impurities and salt content.

  For example, the submergence sensor 41 provided in the node 4 is connected to the control circuit 52 by a circuit as shown in FIG. 6B, and when the node 4 is not submerged, the submergence sensor 41 is connected. In the control circuit 52, the input voltage is at a low level due to the pull-down resistor R4, but the node 4 is submerged and water adheres between the counter electrodes of the submergence sensor 41. When the continuity is established, the input voltage of the control circuit 52 becomes high level by the power supply VDD.

  The control circuit 52 determines whether an abnormality (in this case, submergence) has occurred in the node 4 depending on whether the input voltage from the submergence sensor 41 is at a low level or a high level.

  In addition, when the node 4 connected to the bus monitoring unit 5 has a termination resistor and plays a role of termination in the vehicle control system 1, the bus monitoring unit 5 is configured as shown by a broken line in FIG. In addition to the control circuit 52 and the switch circuit 53, a termination resistor R3 is provided as an alternative when the node 4 is disconnected from the bus monitoring unit 5.

  When the bus monitoring unit 5 includes the termination resistor R3, the state of the switch circuit 53 is not short-circuited or opened to the second communication bus line 34, but short-circuited to the second communication bus line 34. This is connected to the termination resistor R3.

  According to the above-described configuration, the communication device 2 disconnects only the node 4 where the abnormality has occurred and the second communication bus line 34 connected to the node 4 from the first communication bus line 33. One communication bus line 33 itself is not separated and divided, and the vehicle control system 1 configured by the other normal nodes 4 and the first communication bus line 33 can be maintained.

  Note that in this embodiment as well as in the above-described embodiment, the bus monitoring unit 5 is disconnected from the second communication bus line 34 when the cause of the abnormality of the node 4 where the abnormality has occurred is resolved. A configuration including a return control unit that reconnects the node 4 to the second communication bus line 34 may be employed.

  The return control unit in the present embodiment is realized by adding the following functions to the control circuit 52. That is, the control circuit 52 includes a memory for storing the disconnection of the node 4, and continues to input the signal CANH and the signal CANL even after the node 4 is disconnected. Is within the appropriate value range set in advance, or when the state within the appropriate value range continues for a predetermined time or more, it is determined that the abnormality that has occurred in the node 4 has been resolved. Then, the information indicating that the node 4 stored in the memory is disconnected is deleted.

  Then, the control circuit 52 switches the state of the two switches of the switch circuit 53 from the connection to the termination resistor R3 to the short circuit to the second communication bus line 34, so that the node in which the abnormality is eliminated 4 is reconnected to the communication bus line 3.

  According to the above configuration, when the abnormality is temporary and the abnormal state is resolved, the return control unit returns the vehicle control system 1 to the original state. Can be recovered from an unstable state divided into a plurality of groups at an early stage, and the possibility of an abnormal operation occurring due to the unstable state continuing for a long time can be reduced.

  Hereinafter, the communication device 2 includes the bus monitoring unit 5 that branches the communication bus line 3 from the first communication bus line 33 that is a main line to the second communication bus line 34 that is a branch line, and the second communication bus line When an abnormality occurs in the node 4 connected to the bus 34, the bus monitoring unit 5 is configured to disconnect the node 4 and disconnect the communication bus line 3 and return the communication bus line 3. This will be described based on the flowchart shown in FIG.

  When the bus monitoring unit 5 detects that the submergence sensor 41 provided in the node 4 detects submergence (SB1) and determines that a communication abnormality has occurred in the communication bus line 3 based on the voltage of the communication bus line 3 ( SB2), the node 4 where the occurrence of the abnormality is detected is disconnected from the communication bus line 3 (SB3).

  When the disconnected node 4 includes a termination resistor (SB4), the bus monitoring unit 5 connects to the termination resistor R3 provided therein instead of the termination resistor (SB5).

  In step SB1 or step SB2, when the bus monitoring unit 5 does not recognize that an abnormality has occurred in the node 4 (SB1, SB2), the return control unit is a node connected to the bus monitoring unit 5 4 is the node 4 previously disconnected in step SB3 (SB6), at a timing when the communication bus line 3 passing through the bus monitoring unit 5 is not used for communication of other nodes 4 (SB7). Then, the following return processing is performed.

  That is, when the disconnected node 4 includes a termination circuit (SB8), the return control unit cancels the connection with the termination resistor R3 connected in step SB5 (SB9), and disconnects the node. 4 is returned (SB10), and when the disconnected node 4 does not include the termination resistor (SB8), the termination resistor R3 is not connected in step SA5, and thus the termination resistor is not connected. The disconnected node 4 is returned as it is (SB10).

  Similar to the above-described embodiment, the communication device 2 includes the bus monitoring unit 5 that disconnects the communication bus line 3 with the abnormality occurrence point as a boundary when an abnormality occurs in the communication bus line 3. The monitoring unit 5 may have the following configuration.

  In other words, the bus monitoring unit 5 monitors the communication bus line 3 to which the ECUs as the plurality of nodes 4 are connected, and when the abnormality occurs in the communication bus line 3, the communication bus line is defined with the abnormality occurrence point as a boundary. 3 may be configured such that the ECU disposed outside the passenger compartment is disconnected from the communication bus line 3 when submergence of the communication bus line 3 is detected. Here, “outside the vehicle compartment” means, for example, an engine room.

  This will be described in detail below. The vehicle control system 1 provided with the communication device 2 in the present embodiment has the same configuration as that shown in FIG. That is, the ECU 4 connected to the bus monitoring unit 5 includes a submergence sensor 41, and the control circuit 52 included in the bus monitoring unit 5 is configured to have a voltage level of CANH or CANL of the communication bus line 3. Is within the range of the preset appropriate value, and the submersion sensor 41 detects that the ECU 4 is submerged, the switch circuit 53 is switched to a state where it is not connected to the ECU 4.

  For example, in the case of the vehicle control system 1 illustrated in FIG. 1, when any of the bus monitoring units 5 provided in the vehicle control system 1 detects the submergence of the communication bus line 3, the vehicle control system 1 is disposed in the engine room. The bus monitoring unit 5C connected to the HV-ECU 41 which is the ECU 4 disconnects the HV-ECU 41 from the communication bus line 3 regardless of whether or not the bus monitoring unit 5 has detected submersion.

  Since the vehicle is a moving means, it is difficult to avoid part or all of the vehicle being submerged during heavy rain or when it is necessary to move in a flooded area. Further, in a vehicle, there is a higher possibility that the outside of the passenger compartment will be submerged than in the passenger compartment. Therefore, by quickly disconnecting the ECU 4 arranged outside the passenger compartment, the failure of the other ECU 4 due to the failure of the submerged ECU 4 can be prevented. be able to.

  In the configuration described in the above embodiment, that is, when an abnormality occurs in the communication bus line 3, the nodes 4 are divided into groups with the abnormality occurrence point as a boundary, and communication is performed within each group of the communication bus line 3. And a bus monitoring unit that branches the communication bus line 3 from the first communication bus line 33 to the second communication bus line 34. The bus monitoring unit 5 may be combined with a configuration in which the node 4 is disconnected when an abnormality occurs in the node 4 connected to the second communication bus line 34.

  More specifically, the bus monitoring unit 5 in the present embodiment has a configuration as shown in FIG. That is, the bus monitoring unit 5 is configured to include a control circuit 52 and three switch circuits 53, and the control circuit 52 includes the voltage of the communication bus line 3 and the submersion provided in the node 4. The three switch circuits 53 are controlled based on the sensor 41.

  The bus monitoring unit 5 has a configuration in which the termination resistors R5 provided in the three switch circuits 53 are shared by the three switch circuits 53 as shown in FIG. 4B. There may be.

  In the above-described embodiment, the configuration in which the communication bus line 3 is a differential signal system has been described. However, the communication bus line 3 is not limited thereto. For example, the communication bus line 3 may be configured by Ethernet (registered trademark of Xerox Corporation) or LIN (Local Interconnect Network).

  In the above-described embodiment, the configuration has been described in which the node 4 includes the submergence sensor 41 and copes with submergence of a vehicle or the like. For example, the structure which copes with a fire by detecting high temperature with temperature sensors, such as a thermistor, may be sufficient.

  In the above-described embodiment, the configuration in which the node 4 is an ECU that controls each part of the vehicle has been described. However, the node 4 is not limited to this and may be a personal computer or the like.

  In the above-described embodiment, the communication device 2 has been described as being applied to the vehicle control system 1 in which a plurality of electronic control units 4 cooperate to control a predetermined control target. However, the communication device 2 is applied. This is not limited to the vehicle control system 1 and can be applied to, for example, control systems for various electronic devices.

  The embodiment described above describes an example for realizing the present invention, and the specific configuration of each part should be appropriately changed and designed according to the system to be constructed as long as the effects of the present invention are achieved. Is possible.

Block diagram of a vehicle control system to which the communication device of the present invention is applied Illustration of the bus monitoring unit Illustration of the vehicle control system divided into two groups (A) shows the bus monitoring unit sharing the termination resistance in FIG. 2, and (b) is an explanatory diagram showing the bus monitoring unit sharing the termination resistance in FIG. Flowchart for explaining disconnection and return of communication bus line in a configuration in which a plurality of nodes are divided into groups (A) shows the bus monitoring part of the structure which isolate | separates a node, (b) is explanatory drawing which shows the connection of a submergence sensor and a control circuit. Flowchart for explaining node disconnection and recovery in a node disconnection configuration Explanatory diagram of the bus monitoring unit that combines a configuration that divides multiple nodes into groups and a configuration that separates nodes

Explanation of symbols

1: Vehicle control system 2: Communication device 3: Communication bus line (communication line)
33: First communication bus line 34: Second communication bus line 4: Node (electronic control unit)
5: Bus monitoring unit (monitoring device)

Claims (5)

A monitoring device for monitoring a communication line to which a plurality of nodes are connected,
A plurality of switching means for dividing the communication line into two or more communication lines;
Control means for controlling the switching means to identify an abnormality occurrence location when an abnormality occurs in the communication line, and for controlling the switching means to separate the communication line to which the identified abnormality occurrence location belongs from other communication lines A monitoring device comprising: A monitoring device that monitors a communication line to which a plurality of nodes are connected, and branches the communication line from a first communication line to a second communication line,
A plurality of switching means for dividing the first communication line and the second communication line;
A monitoring device comprising control means for disconnecting a node connected to the second communication line when an abnormality occurs.   2. The communication circuit according to claim 1, wherein the communication line is a bus line based on a differential signal system, and the termination circuit of the communication line is switched when a termination circuit is provided at a node connected to the communication line. 2. The monitoring device according to 2. A monitoring device that monitors a communication line to which a plurality of nodes are connected, and disconnects the communication line with an abnormality occurrence point as a boundary when an abnormality occurs in the communication line,
The monitoring device characterized in that the node is composed of an electronic control unit that controls each part of the vehicle, and the electronic control unit arranged outside the passenger compartment is separated from the communication line when the submergence of the communication line is detected. A monitoring method for a network system comprising a plurality of monitoring devices according to any one of claims 1 to 4, wherein a plurality of nodes are connected to a communication line, and each node can communicate with each other via the communication line. There,
When an abnormality occurs in the communication line or any one of the nodes, each monitoring device identifies an abnormality occurrence location and separates the communication line to which the identified abnormality occurrence location belongs from the other communication lines How to monitor the system.

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