JP6365876B2 - node - Google Patents

Description

  The present invention relates to a node connected to a communication bus.

  ECUs (also referred to as “nodes”) mounted on each part of the vehicle and connected via a communication bus such as an in-vehicle LAN have unique IDs even if the ECUs have the same function because of communication management needs. Is granted.

  In a communication network system composed of one master and two or more slaves connected to a communication bus, even if the number of slaves connected to the bus increases, the network is not increased without increasing the number of necessary signal lines. There has been devised an ID assignment method for a communication network system that can reliably assign different IDs (see Patent Document 1).

  In a slave used in a communication network configured by daisy chaining one master and a plurality of slaves with a pair of communication buses on the high potential side and the low potential side, on the downstream side of the high potential bus A communication slave has been devised in which an ID for communicating with the master is set in accordance with the level of the potential difference between the upstream terminal of the inserted resistance element and the low potential bus (see Patent Document 2).

JP 2005-229561 A JP 2011-155356 A

  In the prior art, when the IDs of some nodes become abnormal due to a temporary disturbance such as noise in the communication network system, the failure of the nodes or the trouble of the operation of other normal nodes There is a risk of becoming. Also, with the conventional technology, the return operation can be performed only during a specific operation such as when the engine is started, and even in this case, the normal ID node also reassigns the ID, so that the ID of another node can be abnormal. There is also sex.

  Both Patent Documents 1 and 2 are configured to have one master node and a plurality of slave nodes. However, the present invention is not applicable to a configuration in which a master node does not exist, such as determining and setting the node ID by software or connected hardware (wire harness or the like).

  Against the background of the above problems, the present invention provides a node that enables automatic resetting of an ID by a simple method that suppresses cost increase.

  A node for solving the above problem is a node connected to a communication bus, an ID acquisition unit that acquires an ID for identifying the node, a communication unit that performs data communication via the communication bus, A monitoring unit that monitors the communication state of the data, and an ID determination unit that determines whether or not the acquired ID is appropriate based on the communication state of the monitored data. When it is determined that is not appropriate, the ID acquisition unit reacquires the ID.

  If the ID becomes abnormal, not only does the operation of the node become abnormal, but it may also affect other normal nodes. In the present invention, automatic recovery of ID can be performed on a node-by-node basis by detecting at each node a communication error that is expected to occur due to an abnormal ID. As a result, the influence of the node having the abnormal ID on the node having the normal ID can be reduced, and the communication network system (including the communication bus and the node connected to the communication bus) can be trusted. Can be expected. Further, in order to recover the ID from an abnormal state, it has been conventionally necessary to stop the engine or reconnect the battery. However, in the present invention, since the automatic recovery is performed, these operations are unnecessary.

The figure which shows the connection structural example of a node. The figure which shows another example of the connection structure of a node. The figure which shows the structural example of a node. The flowchart which shows ID acquisition processing. The figure which shows the example at the time of ID acquisition abnormality. The figure which shows another example at the time of ID acquisition abnormality. The flowchart which shows another example of ID acquisition processing.

  FIG. 1 shows a communication network system 1 in a vehicle, for example, in which a node of the present invention is connected to a communication bus 60. The master node 10 and the nodes 20, 30, 40, 50 are connected to the communication bus 60. A node (generic name for 20, 30, 40, and 50, the same applies hereinafter) corresponds to a slave node. In FIG. 1, each node performs communication according to the LIN protocol. The nodes 20, 30, 40, and 50 are assigned A, B, C, and D as IDs for identifying the nodes, respectively.

  The LIN protocol uses a master-slave system in which the master node 10 controls the entire communication. The master node 10 controls communication of the entire LIN network based on the LIN schedule in which the ID to be transmitted, the order of transmission, and the time interval for transmission are defined. The master node 10 transmits a transmission request “token” to the communication bus 60 based on the LIN schedule. The node monitors the token transmitted from the master node 10, and according to the “token”, the node that transmits data transmits data after the token.

  The above configuration is “a master node is connected to the communication bus, the node operates as a slave node, and the communication unit communicates with the master node according to the LIN protocol”. With this configuration, the configuration of the present invention can be applied to a master-slave type communication network system using the LIN protocol.

  FIG. 2 shows another example of the configuration of the communication network system 1. The example of FIG. 2 is a “multi-master method” that enables equal bus access to nodes (20, 30, 40, 50) connected to the communication bus 60 in a line structure such as a CAN (Controller Area Network). Is used. Also, ID assignment is the same as in FIG. This configuration is “the node and the communication bus constitute a multi-master communication network system”. With this configuration, the configuration of the present invention can be applied to a multi-master communication network system.

  FIG. 3 shows a configuration example of the node 20. The node 20 includes an operation unit 21 (ID acquisition unit, monitoring unit, ID determination unit of the present invention), input circuit 22, driver circuit 23, communication I / F 24 (communication unit, monitoring unit, ID acquisition unit of the present invention), A memory 25 and an ID setting unit 26 are included.

  The arithmetic unit 21 may include a CPU and peripheral circuits, or may be configured in hardware as one or a plurality of ICs or ASICs including a logic circuit or the like.

  The input circuit 22 performs signal processing such as waveform shaping and A / D conversion of input signals from the switch group 27 and the sensor group 28. The driver circuit 23 drives and controls the actuator group 29. The communication I / F 24 is a communication interface circuit for performing data communication with other nodes via the communication bus 60. The memory 25 includes, for example, a flash memory that is a nonvolatile storage medium, and stores data necessary for the operation of the node 20.

  The ID setting unit 26 is for acquiring an ID based on the state of the hardware, and includes, for example, a dip switch group or a resistance element connected to the power supply side or the ground side. The ID setting unit 26 is connected to the ID setting terminal of the calculation unit 21, and the calculation unit 21 detects the state of the ID setting unit 26 to acquire the ID. For example, since switching is set in two ways, short (connected to the ground side) or open (connected to the power supply side) for each ID setting terminal, nodes corresponding to the square of the number of ID setting terminals can be identified.

  The above-described configuration is “including an ID setting unit for setting an ID, and the ID acquisition unit acquires an ID from the ID setting unit”. With this configuration, it is possible to reliably acquire an ID regardless of the configuration form of the communication network system and regardless of the operating state of other nodes.

  The node 20 is connected to a switch group 27 on which a user inputs an operation, for example, a sensor group 28 including a rotation sensor, a pressure sensor, a temperature sensor, and the like, for example, an actuator group 29 including a motor, a solenoid, and the like.

  With the above configuration, the node 20 receives the control command from the master node 10 received via the communication bus 60 or data acquired from another node, the switch group 27 acquired via the input circuit 33, the sensor group 28, and the actuator. An operation control command value is calculated based on the operation state of the group 29, and drive control of the actuator group 29 is performed via the driver circuit 23.

  The nodes (30, 40, 50) have substantially the same configuration as that of the node 20, but the configuration (the presence or absence of the switch group, sensor group, actuator group, or configuration content) differs depending on the function realized by the node.

  FIG. 4 shows an ID acquisition process included in the control program stored in the memory 25 of the node 20 (the same applies to other nodes) and executed by the arithmetic unit 21. First, when the node 20 is connected to the battery, when the ignition switch for turning on the motor (engine or motor) of the vehicle is turned on, or when the node 20 is connected to the communication bus 60 (ie, ID acquisition timing), an ID is acquired using any of the following methods (S11). The acquired ID is stored in a predetermined area of the memory 25.

(Acquire ID based on hardware status)
As described above, the calculation unit 21 acquires the ID by detecting the state of the ID setting unit 26.

(Acquire ID by software)
An ID is stored in advance in the memory 25 and is read out and acquired at the ID acquisition timing. In this case, the memory 25 corresponds to the ID setting unit of the present invention.
In the configuration of FIG. 1, the ID of each node is stored in the master node 10. The node 20 transmits node information (for example, manufacturer information and function information) to the master node 10 at the ID acquisition timing, and receives and acquires the ID of the own node from the master node 10. This configuration is “the ID acquisition unit acquires an ID from the master node”. With this configuration, the node (slave node) does not need to hold its own ID, and an ID setting unit is not necessary. In addition, the degree of freedom of ID setting for the nodes on the communication network system is increased, and the master node can appropriately set (including change) the ID of the slave node.

  Next, the timer A for monitoring the data transmission state and the timer B for monitoring the data reception state are reset (zero cleared), and measurement is started (S12).

  Next, the data transmission state is monitored to determine whether or not the data transmission is performed correctly. The transmission data is stored in the buffer 24 a (data storage unit of the present invention) included in the communication I / F 24 and transmitted to the communication bus 60. The communication I / F 24 or the arithmetic unit 21 checks the difference between the transmission data stored in the buffer 24a and the data sampled on the communication bus 60 (that is, the data actually transmitted). Is determined not to be performed correctly.

  The above-described configuration is as follows: “The communication unit includes a data storage unit that stores data for transmission, and monitoring is performed by comparing the state of the communication bus at the time of data transmission with the data for transmission stored in the data storage unit. By doing so, it is monitored whether or not data transmission is properly performed. " With this configuration, when the so-called communication unit has a bit monitoring function, it is possible to determine whether or not the acquired ID is appropriate using the bit monitoring function.

  When the data transmission is correctly performed (S13: yes), the timer A is reset (S14), and the process proceeds to step S15. The timer A restarts measurement from zero. On the other hand, when the data transmission is not performed correctly (S13: no), the process proceeds to step S15 without doing anything.

  In step S15, it is determined whether or not data from the master node 10 or another node (30, 40, 50) is correctly received. CRC check, form check, staff check, etc. are performed, and only normal data is determined. Also, data having a plurality of nodes as transmission destinations, such as broadcast frames, is not determined, and only data having only the own node as a transmission destination is determined.

  The above-described configuration is “the monitoring unit monitors whether or not data is properly received based on whether or not data whose destination is only a node has been received”. Data having a plurality of or unspecified nodes as transmission destinations may differ in data configuration from data having a specific node as a transmission destination, and may be received even by a node having an abnormal ID. With this configuration, it is possible to more reliably monitor whether or not the data is properly received by limiting the transmission destination to data of only itself.

  When the data is correctly received (S15: yes), the timer B is reset (S16), and the process proceeds to step S17. Timer B resumes measurement from zero. On the other hand, when the data transmission is not correctly performed (S15: no), the process proceeds to step S17 without doing anything.

  In step S17, it is determined whether or not the timer A has timed out (a predetermined time has elapsed). When the timer A times out, that is, when the state in which data transmission is not performed properly continues beyond a predetermined time (S17: yes), the process returns to step S11 to acquire the ID again.

  The above-mentioned configuration is that “the monitoring unit monitors whether or not the data transmission is properly performed, and the ID determination unit determines that the state in which the data transmission is not performed properly is a predetermined time. When it continues beyond, it is determined that the acquired ID is not appropriate. " With this configuration, it is possible to determine whether or not the acquired ID is appropriate at the time of data transmission without adding a monitoring circuit or the like separately. Further, by appropriately setting the time for determination, it is possible to prevent a temporary transmission error due to noise or the like from being misidentified as being due to an improper ID.

  On the other hand, when the timer A has not timed out (S17: no), it is determined whether or not the timer B has timed out. When the timer B times out, that is, when the state in which data is not properly received continues for a predetermined time (S18: yes), the process returns to step S11, and the ID is acquired again. On the other hand, when the timer B has not timed out (S18: no), the process returns to step S13.

  The above configuration is “the monitoring unit monitors whether or not the data is properly received, and the ID determination unit exceeds the predetermined time when the data is not properly received. The acquired ID is not appropriate ”. With this configuration, it is possible to determine whether or not the acquired ID is appropriate at the time of data reception without adding a monitoring circuit or the like. Further, by appropriately setting the time for determination, it is possible to prevent a temporary reception error due to noise or the like from being misidentified as being due to an improper ID.

  The timeout determination values of timer A and timer B are set to relatively long values such as several seconds, for example. This is to prevent re-acquisition of the ID due to a sudden and non-continuous communication error that occurs due to a reason other than that the ID is not appropriate, such as noise.

  The flow of the ID acquisition process when the ID acquisition is abnormal will be described with reference to FIGS. FIG. 5 is a master-slave method, and when the ID of the node 30 that is originally “B” becomes the same “C” as the node 40, that is, a plurality of nodes having the same ID are connected to the communication bus 60. It is in a state.

  When the node 30 tries to transmit data based on a command from the master node 10, the node 40 having the same ID (this is the correct ID) also transmits the data almost simultaneously, so a data collision occurs and the data is transmitted. Can not. Therefore, in the above bit monitoring, transmission data and data sampled on the communication bus 60 are different, so data transmission fails. In the ID acquisition process of FIG. 4, the timer A is not reset through step S13: no.

  As shown in FIG. 2, when the master-slave system is not used, that is, when each node transmits data spontaneously, data collision can occur. Once data collision occurs, data retransmission is attempted. Furthermore, the possibility of data collision increases and data transmission fails. Therefore, timer A is not reset.

  On the other hand, the reception of data at the node 30 is normally performed because the transmission source transmits the data to the node 40 and receives the data. As a result, the timer B is reset, but the timer A times out, and in the ID acquisition process of FIG. 4, the ID is reacquired through step S17: yes.

  At this time, since the data transmission also fails in the node 40, the ID is reacquired similarly to the node 30. Since the operations of the nodes 20 and 50 are not affected, these two nodes do not re-acquire the ID.

  As described above, even if the configuration of the communication network system 1 is either the master-slave method (FIG. 1) or the multi-master method (FIG. 2), the duplicate ID is acquired when the node ID is duplicated. The ID is reacquired at the node that has been selected.

  FIG. 6 shows a master-slave system, where the ID of the node 30 that is originally “B” is “E”, that is, in a state where a node having an ID that cannot exist is connected to the communication bus 60. is there.

In FIG. 6, at the time of data transmission, the following two situations can be considered.
When the node 30 transmits data based on the command from the master node 10, the command for ID “E” is not transmitted, and therefore no data is transmitted. If it is determined that the data transmission is unsuccessful when no data is transmitted, the timer A is not reset.
Data can be transmitted from the master node 10 when an event trigger frame used for an event with a low occurrence frequency that can process transmissions from a plurality of nodes by LIN is transmitted. The master node 10 determines that the data is not proper, but the data is transmitted normally. At this time, timer A is reset.
As shown in FIG. 2, when the master-slave system is not used, that is, when each node transmits data voluntarily, it is different from the IDs of other nodes, so there is a possibility that data transmission is normally performed. is there. At this time, timer A is reset.

  Therefore, at the time of data transmission, the timer A may or may not be reset depending on the network configuration.

  On the other hand, since the data addressed to the ID “E” is not transmitted from the master node 10 and other nodes, the data reception at the node 30 is not performed at all. Therefore, in the ID acquisition process of FIG. 4, the timer B is not reset through step S15: no. As a result, the timer B times out, and in the ID acquisition process of FIG. 4, the process passes through step S18: yes, and the node 30 re-acquires the ID. The other nodes (20, 40, 50) Do not acquire.

  FIG. 7 shows another example of the ID acquisition process. Since this process is a modification of FIG. 4, the same reference numerals are given to the same process steps as those in FIG. 4, and detailed description thereof will be omitted. The difference from FIG. 4 is that counter A is used instead of timer A.

  After acquiring the ID in step S11, the counter A is reset (zero cleared) (S11A). Next, only timer B (timer A is not used) is reset and measurement is started (S12A).

  Next, when the data transmission from the node is successful (S13: yes), the counter A is decremented (a predetermined value such as 1 is subtracted from the current counter value) (S14A). On the other hand, when data transmission from the node fails (S13: no), the counter A is incremented (a predetermined value such as 8 is added to the current counter value) (S14B). The added value and the subtracted value may be the same value or different values, but it is desirable to make the added value larger than the subtracted value in order to ensure error determination.

  After determining whether or not the data has been successfully received (steps S15 and S16), in step S17A, it is determined whether or not the value of the counter A has exceeded a predetermined threshold value. For example, the threshold value is determined so that the number of failures (ten times to several tens times) that cannot occur in normal time is obtained.

  When the value of the counter A exceeds the threshold value (S17A: yes), the process returns to step S11, and the ID is reacquired. On the other hand, when the value of the counter A does not exceed the threshold value (S17A: no), the process proceeds to step S18 and the timer B is determined.

  The above-described configuration is “the monitoring unit monitors whether or not data transmission is properly performed, and the ID determination unit includes a determination counter and determines when data transmission is not performed properly. Counter is added when the data is properly transmitted, and when the value of the determination counter exceeds a predetermined threshold, the acquired ID is not appropriate. Judgment ". Also with this configuration, it is possible to determine whether or not the acquired ID is appropriate at the time of data transmission without adding a monitoring circuit or the like separately. In addition, by appropriately setting a threshold value for determination, it is possible to prevent a temporary transmission error due to noise or the like from being misidentified as being due to an inappropriate ID.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

1 communication network system 10 master node 20, 30, 40, 50 node (slave node)
21 operation part (ID acquisition part, monitoring part, ID determination part)
24 Communication I / F (communication unit, monitoring unit, ID acquisition unit)
24a buffer (data storage unit)
25 Memory (ID setting part)
26 ID setting part 60 Communication bus

Claims (12)

A node connected to a communication bus,
The node is
An ID acquisition unit for acquiring an ID for identifying the node;
A communication unit for communicating data via the communication bus;
A monitoring unit for monitoring a communication state of the data;
An ID determination unit that determines whether or not the acquired ID is appropriate based on the monitored communication state of the data;
With
The ID determination unit, when the acquired ID is determined not intended proper, the ID acquisition unit reacquires the ID,
The monitoring unit monitors whether or not the transmission of the data is properly performed,
The ID determination unit determines that the acquired ID is not appropriate when a state where the transmission of the data is not properly performed continues for a predetermined time. . A node connected to a communication bus,
The node is
An ID acquisition unit for acquiring an ID for identifying the node;
A communication unit for communicating data via the communication bus;
A monitoring unit for monitoring a communication state of the data;
An ID determination unit that determines whether or not the acquired ID is appropriate based on the monitored communication state of the data;
With
The ID determination unit, when the acquired ID is determined not intended proper, the ID acquisition unit reacquires the ID,
The monitoring unit monitors whether the data is properly transmitted,
The ID determination unit includes a determination counter,
When the transmission of the data is not properly performed, the determination counter is added,
When the transmission of the data is properly performed, the determination counter is subtracted,
A node characterized in that when the value of the determination counter exceeds a predetermined threshold value, the acquired ID is determined to be inappropriate. A node connected to a communication bus,
The node is
An ID acquisition unit for acquiring an ID for identifying the node;
A communication unit for communicating data via the communication bus;
A monitoring unit for monitoring a communication state of the data;
An ID determination unit that determines whether or not the acquired ID is appropriate based on the monitored communication state of the data;
With
The ID determination unit, when the acquired ID is determined not intended proper, the ID acquisition unit reacquires the ID,
The monitoring unit monitors whether the data is properly received,
The node, wherein the ID determination unit determines that the acquired ID is not appropriate when a state in which the data is not properly received continues for a predetermined time. The monitoring unit monitors whether or not the transmission of the data is properly performed,
The ID determination unit, a state in which transmission of the data has not been properly is, when continued beyond a predetermined time, according to judges claim 3 and the acquired ID is not one proper node. The monitoring unit monitors whether or not the transmission of the data is properly performed,
The ID determination unit includes a determination counter,
When the transmission of the data is not properly performed, the determination counter is added,
When the transmission of the data is properly performed, the determination counter is subtracted,
The node according to claim 3 , wherein when the value of the determination counter exceeds a predetermined threshold, the acquired ID is determined not to be appropriate. The communication unit includes a data storage unit that stores data for transmission,
The monitoring unit monitors whether or not the data is properly transmitted by comparing the state of the communication bus at the time of data transmission and the data for transmission stored in the data storage unit. The node according to any one of claims 1, 2, 4, and 5 . The monitoring unit monitors whether the data is properly received,
The ID determination unit, wherein when the state reception is not performed properly in the data has continued beyond a predetermined time, the acquired ID is proper ones not the judges claim 1 or claim 2 Node described in. The node according to claim 3 or 7 , wherein the monitoring unit monitors whether or not data is properly received based on whether or not data whose destination is only the node is received. . A master node is connected to the communication bus,
The node acts as a slave node;
The node according to claim 1 , wherein the communication unit communicates with the master node according to a LIN protocol. The node according to claim 9 , wherein the ID acquisition unit acquires the ID from the master node. An ID setting unit for setting the ID;
The node according to claim 1 , wherein the ID acquisition unit acquires the ID from the ID setting unit. A node connected to a communication bus,
The node is
An ID acquisition unit for acquiring an ID for identifying the node;
A communication unit for communicating data via the communication bus;
A monitoring unit for monitoring a communication state of the data;
An ID determination unit that determines whether or not the acquired ID is appropriate based on the monitored communication state of the data;
With
When the ID determination unit determines that the acquired ID is not appropriate, only the ID acquisition unit of the node determined that the ID is not appropriate acquires the ID again. Node to perform.

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