JP2015149563A - Network control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set transmission timing in a multiplex communication system having a plurality of communication nodes.SOLUTION: A network control device which is provided in each of a plurality of communication nodes to compose an event-driven network; in which the plurality of communication nodes compose one or a plurality of groups and each communication node transmits a message with information of a group to which each communication belongs and an identifier of the communication node; and which is mounted on one communication node of the plurality of communication nodes and has a control part for setting, with reference to the information of the group to which each communication node belongs and the identifier of each communication node, a transmission order of one communication node in a group based on the identifier of the one communication node and the identifiers of communication nodes other than the one communication node, which belong to the group to which the one communication node belongs.

Description

  The present invention relates to a network control apparatus that controls a network.

  In an event-driven network such as a controller area network (CAN), each node transmits a message at the transmission timing of its own node. When a plurality of nodes transmit messages at the same timing, arbitration is performed, and messages are transmitted in order from the highest priority message.

  When adding an in-vehicle unit to CAN, a technology is known that detects the ID of the in-vehicle unit, compares it with the ID of the operation list of the in-vehicle unit, and reconfigures the network if assignment is not performed according to the operation list. (For example, refer to Patent Document 1).

JP 2006-295426 A

  When a communication node is newly added to the network, it is necessary to design the transmission timing of the message transmitted by the communication node so as not to collide with the message transmitted by the existing communication node. For this reason, every time a communication node is added to the network, the number of man-hours for designing the transmission timing of the communication node increases, and the cost for the design occurs.

  An object of the present invention is to automatically set the transmission timing of a communication node in a multiplex communication system having a plurality of communication nodes.

A network control apparatus according to an embodiment of the disclosure is:
A network control device included in each of a plurality of communication nodes constituting an event-driven network,
After the network is activated, the plurality of communication nodes constitute one or a plurality of groups, and each communication node transmits a message accompanied by an identifier of the communication node and group information to which the communication node belongs,
A network control device mounted on one communication node of the plurality of communication nodes,
Based on the group information to which each communication node belongs and the identifier of each communication node, based on the identifier of the one communication node and the identifier of another communication node other than the one communication node belonging to the group to which the one communication node belongs And a control unit for setting the order of transmission by the one communication node in the group.

  According to the disclosed embodiment, it is possible to automatically set the transmission timing of a communication node in a multiple 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 functional block diagram which shows one Example of a 1st communication node. It is a figure which shows one Example (the 1) of transmission timing. It is a figure which shows one Example (the 2) of transmission timing. It is a figure which shows one Example of operation | movement of a communication system. It is a flowchart which shows one Example of operation | movement of a 1st communication node. It is a figure which shows an example of a transmission timing. It is a figure which shows an example of a transmission timing.

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 an event-driven network such as CAN is applied. The communication system can be applied to information LAN, powertrain LAN, body LAN, and the like.

  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 to the fifth communication node 500 are connected by wire through the communication bus 10.

  Although FIG. 1 shows a case where a communication system is constituted by five communication nodes, it may be constituted by two to four communication nodes, or may be constituted by six or more communication nodes.

  When CAN is applied to the communication system, the communication bus 10 includes 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 the communication bus 10. In FIG. 3, CANH and CANL are represented by a single solid line.

  The first communication node 100 to the fifth communication node 500 are assigned identifiers that uniquely identify the communication nodes.

  Further, when the communication system is activated, the first communication node 100 to the fifth communication node 500 spontaneously form a group. For example, a first group is configured by the first communication node 100 to the third communication node 300, and a second group is configured by the fourth communication node 400 to the fifth communication node 500.

  Each communication node transmits a message accompanying the group information to which the communication node belongs (hereinafter referred to as “group information loading message”) together with the identifier of the communication node. CANID or the like may be used as the identifier of the communication node, or may be set separately in the message. However, it is a unique value within the group. Each communication node can recognize the number of communication nodes other than the own communication node belonging to the group to which the own communication node belongs by receiving the group information loading message transmitted from the other communication node. Further, each communication node recognizes the transmission order in the group to which the own communication node belongs.

  Each communication node sets a plurality of transmission timings, and assigns the own communication node to each transmission timing based on the group to which the own communication node belongs and the identifier of the own communication node.

<First communication node 100>
FIG. 2 shows an embodiment of the first communication node 100. In FIG. 2, the hardware configuration and the software configuration of the first communication node 100 are mainly shown separately. FIG. 2 can also be applied to the hardware configuration and software configuration of the second communication node 200 to the fifth communication node 500.

  The first communication node 100 includes a transceiver 102 and a microcomputer 104. The microcomputer 104 includes a controller 106, a driver 108, an interface 110, a COM 112, and an application 114. Here, the controller 106 is hardware, and includes a transmission message box (MBOX: Message BOX) 1062 and a reception MBOX 1064. The driver 108 is software, and includes a transmission buffer 1082 and a reception buffer 1084. The interface 110 is software. The COM 112 is software and has two signal buffers 1122 and 1124. The COM 112 does not necessarily have two buffers, and may have one signal buffer 1124. The application 114 is software.

  The transceiver 102 is connected to the communication bus 10 and transmits a group information loading message from the transmission MBOX 1062 of the controller 106 to the communication bus 10 and receives the group information loading message from the communication bus 10 under the control of the driver 108. Input to the reception MBOX 1064 of the controller 106. The transceiver 102 sends an inverted signal to CANH and CANL when transmitting a group information loading message, and receives a group information loading message from the voltage difference between CANH and CANL. It is determined whether it is “1” or “0”.

  The controller 106 is connected to the transceiver 102 and performs serial communication with other communication nodes via the communication bus 10. The group information loading message from the driver 108 is input to the transmission MBOX 1062, and the group information loading message from the transceiver 102 is input to the reception MBOX 1064. The controller 106 transmits the group information loading message input to the transmission MBOX 1062 from the transceiver 102 and outputs the group information loading message input to the reception MBOX 1064 to the reception buffer 1084 of the driver 108.

  The driver 108 temporarily stores the group information loading message input via the interface 110 in the transmission buffer 1082, and temporarily stores the group information loading message from the reception MBOX 1064 in the reception buffer 1084.

  The interface 110 is an interface between the COM 112 and the driver 108.

  The COM 112 is positioned above the driver 108 via the interface 110. The COM 112 creates a PDU of a group information mounting message to be transmitted to another communication node. The COM 112 is supplied with a signal transmitted from the application 114 to another communication node and a message identifier such as a message ID indicating a group information loading message. The COM 112 temporarily stores a signal to be transmitted to another communication node in the signal buffer 1124. The COM 112 creates a PDU accompanied by a signal to be transmitted to another communication node and a message identifier, and stores the PDU in the transmission buffer 1082. An existing message can be applied by preparing a message identifier representing a group information loading message. Also, a new group information loading message may be defined and used. The COM 112 notifies the controller 106 by an interrupt process or a reception flag when transmitting the created PDU.

  Further, the PDU of the group information loading message is input to the COM 112 from the reception buffer 1084. The COM 112 extracts a signal attached to the input PDU of the group information loading message and stores it in the signal buffer 1124. A message identifier such as a message ID for determining a message from the application 114 is input to the COM 112. The controller 106 operates according to the application by receiving an activation signal when the communication system is powered on.

  When the activation signal is input to the controller 106, the COM 112 starts the filtering process of the PDU of the group information loading message input from the reception buffer 1084. The COM 112 stores a signal acquired by the filtering process in the signal buffer 1124 and notifies the controller 106 by an interrupt process or a reception flag.

  The application 114 is positioned above the COM 112. The application 114 is software that causes the controller 106 to function as the first communication node 100.

<Function of First Communication Node 100>
FIG. 3 is a functional block diagram showing the first communication node 100. FIG. 3 mainly shows processing executed by the transceiver 102 of the first communication node 100 and the controller 106 of the microcomputer 104. 3 can also be applied to the functional blocks of the second communication node 200 to the fifth communication node 500.

  The first communication node 100 functions as a reception unit 1022, a transmission unit 1024, a group configuration recognition unit 1068, a transmission timing adjustment unit 1070, and a group information loading message creation unit 1072.

  The functions of the reception unit 1022 and the transmission unit 1024 are executed by the transceiver 102. The functions of the group configuration recognition unit 1068, the transmission timing adjustment unit 1070, and the group information loading message creation unit 1072 are executed by the controller 106.

  The CPU mounted on the controller 106 operates in accordance with the application 114, thereby functioning as a group information mounting message creation unit 1072. The group information loading message creation unit 1072 creates a group information loading message with the identifier of the first communication node and the group information to which the first communication node belongs. For example, the group information mounting message creating unit 1072 creates a group information mounting message and inputs it to the transmission unit 1024 in response to an activation signal input when the communication system is turned on.

  The transmission unit 1024 is connected to the group information mounting message creation unit 1072. The transceiver 102 functions as the transmission unit 1024 by operating according to the driver 108. The transmission unit 1024 transmits the group information mounting message from the group information mounting message creation unit 1072 to the communication bus 10.

  The group information loading message transmitted from the first communication node 100 is received by the second communication node 200-the fifth communication node 500.

  On the other hand, the first communication node 100 receives the group information loading message transmitted by the second communication node 200-the fifth communication node 500.

  The transceiver 102 operates according to the driver 108 to function as the receiving unit 1022. The receiving unit 1022 receives the group information loading message transmitted by the second communication node 200-the fifth communication node 500. The receiving unit 1022 inputs the received group information loading message transmitted by the second communication node 200 to the fifth communication node 500 to the group configuration recognition unit 1068.

  Group configuration recognizing unit 1068 is connected to receiving unit 1022. The CPU mounted on the controller 106 operates according to the application 114 to function as the group configuration recognition unit 1068. Based on the group to which the first communication node belongs and the group information attached to the group information loading message from the second communication node 200 to the fifth communication node 500, the group configuration recognition unit 1068 The number of communication nodes belonging to the group to which the communication node belongs is recognized.

  Further, the group configuration recognition unit 1068 determines the transmission order based on the identifier of the first communication node and the identifiers of other communication nodes other than the first communication node belonging to the group to which the first communication node belongs. recognize. For example, the group configuration recognizing unit 1068 arranges the identifier of the first communication node and the identifiers of other communication nodes belonging to the group to which the first communication node belongs in ascending or descending order. Recognize the order in which communication nodes transmit. Here, the descending order or ascending order is an example, and can be set as appropriate. For example, the transmission order may be calculated by performing a predetermined calculation. The group configuration recognition unit 1068 inputs, to the transmission timing adjustment unit 1070, group information to which the first communication node 100 belongs and information indicating the order in which the first communication node 100 transmits.

  Transmission timing adjustment section 1070 is connected to group configuration recognition section 1068. The CPU mounted on the controller 106 functions as the transmission timing adjustment unit 1070 by operating according to the application 114. Based on the group information to which the own first communication node 100 belongs and the information indicating the order in which the own first communication node 100 transmits, the transmission timing adjustment unit 1070 is input by the group configuration recognition unit 1068. The transmission unit 1024 is controlled so that transmission can be performed at the transmission timing of the communication node.

  FIG. 4 shows a transmission timing setting example (part 1).

  In the transmission timing setting example (part 1), the transmission timing is set in the time axis direction according to the number of communication nodes belonging to the group.

  In the example shown in FIG. 4, the transmission timing 1-3 is set by equally dividing the time axis direction into a plurality of times, and a communication node is assigned to each transmission timing. For example, when three communication nodes belong to the same group, the second communication node 200, the third communication node 300, and the first communication node 100 are assigned to each of the transmission timings 1-3. The intervals of the transmission timings 1-3 may be biased by dividing the time axis direction unevenly.

  FIG. 5 shows a transmission timing setting example (part 2).

  In the transmission timing setting example (part 2), the transmission timing is set by dividing the time axis direction into a plurality of pieces in advance.

  In the example shown in FIG. 5, transmission timing 1-6 is set by dividing the time axis direction equally, and a communication node is assigned to each transmission timing. For example, when three communication nodes belong to the same group, the second communication node 200, the third communication node 300, and the first communication node 100 are respectively transmitted at the transmission timings 1-3 of the transmission timings 1-6. Assigned. In this case, at the transmission timing 4-6, since there is no communication node to be allocated, nothing is transmitted and nothing is transmitted. The intervals of the transmission timings 1-6 may be biased by dividing the time axis direction unevenly.

<Operation of communication system>
FIG. 6 shows an embodiment of the operation of the communication system.

  In the example shown in FIG. 6, the transmission timing of each communication node is set in the communication system described with reference to FIG. 1.

  In step S602, the communication system is powered off.

  In step S604, when the communication system is powered on, the group information loading message creation unit 1072 of each communication node creates a group information loading message and inputs it to the transmission unit 1024. The transmission unit 1024 transmits the group information mounting message input from the group information mounting message creation unit 1072 to the communication bus 10. An example of information attached to the group information loading message transmitted from the first communication node 100 to the fifth communication node 500 is shown below.

First communication node 100 Group: 1 Identifier (ID): 4
Second communication node 200 Group: 1 Identifier (ID): 2
Third communication node 300 Group: 1 Identifier (ID): 7
Fourth communication node 400 Group: 2 Identifier (ID): 8
Fifth communication node 500 Group: 2 Identifier (ID): 5
Each communication node receives a group information loading message transmitted by another communication node other than its own communication node.

  The group configuration recognition unit 1068 of each communication node includes a group to which the own communication node belongs based on the group to which the own communication node belongs and the group information attached to the group information loading message from the communication node other than the own communication node. Recognize the number of communication nodes belonging to.

  Further, the group configuration recognition unit 1068 recognizes the order of transmission based on the identifier of the own communication node and the identifier of a communication node other than the own communication node belonging to the group to which the own communication node belongs. For example, the group configuration recognition unit 1068 recognizes the order of transmission by the communication node by arranging the identifier of the communication node and the identifiers of other communication nodes belonging to the group to which the communication node belongs.

  A process from when the communication system is turned on until each communication node recognizes the group to which the communication node belongs and recognizes the order of transmission of the communication node in the group is referred to as a “group configuration phase”.

  In step S606, each communication node adjusts the transmission timing based on the group to which the communication node belongs and the order in which the communication node transmits in the group recognized in step S604.

  FIG. 6 shows an example of setting the transmission timing of group 1 in accordance with the transmission timing setting example (part 1) described with reference to FIG.

  The group 1 belongs to the first communication node 100 to the third communication node 300, and the transmission order set between the first communication node 100 and the third communication node 300 (second communication node). 200, first communication node 100, and third communication node 300 in this order), the transmission timing is adjusted. That is, the transmission timing adjustment unit 1070 of the first communication node 100 assigns its own first communication node 100 to the transmission timing 2, and the transmission timing adjustment unit of the second communication node 200 assigns its second communication to the transmission timing 1. The node 200 is assigned, and the transmission timing adjustment unit of the third communication node 300 assigns the third communication node 300 to the transmission timing 3.

  For the fourth communication node 400 to the fifth communication node 500 belonging to the group 2, the transmission order set between the fourth communication node 400 and the fifth communication node 500 (the fifth communication node 500, the fifth communication node 500, The transmission timing is adjusted according to the order of communication node 400 of 4).

  The process that each communication node assigns to the transmission timing is called a “transmission timing adjustment phase”.

  FIG. 7 shows an example of the operation of the first communication node 100. FIG. 7 mainly shows the group configuration phase. The flowchart of FIG. 7 can also be applied to the second communication node 200-the fifth communication node 500.

  In step S702, the communication system is activated.

  In step S704, the group configuration phase is started. When the communication system is activated, an activation signal is input to the controller 106, whereby the group configuration phase is started.

  In step S706, the first communication node 100 enters a message reception waiting state.

  In step S708, the first communication node 100 determines whether a message has been received.

  In step S710, if the group information loading message is not received from the second communication node 200 to the fifth communication node 500 in step S708, it is determined whether or not to end the group configuration phase. When the receiving unit 1022 does not receive the group information loading message from the second communication node 200 to the fifth communication node 500, the group configuration recognition unit 1068 determines whether to end the group phase. If the group configuration phase is not terminated, the process returns to step S706. That is, it returns to the state of waiting for message reception.

  In step S712, when the group configuration phase is terminated in step S710, the first communication node 100 sets the transmission timing of the first communication node 100 from the number of communication nodes in the group and the transmission order. When no message is received and the group configuration phase is terminated, it is assumed that the number of communication nodes in the group and the order in which the first communication node transmits are already set. Therefore, the transmission timing adjustment unit 1070 sets the transmission timing of the first communication node 100 based on the number of communication nodes in the group and the order in which the first communication node 100 transmits.

  In step S714, when receiving a message from the second communication node 200 to the fifth communication node 500 in step S708, the first communication node 100 determines whether or not the received message is a group information loading message. Determine. If it is not a group information loading message, the process returns to step S706.

  In step S716, if it is a group information mounting message in step S714, it is determined whether or not the group represented by the group information attached to the group information mounting message is the same as the first communication node 100 itself. To do. If it is not the same as the first communication node 100, the process returns to step S706.

  In step S718, when the same as the first communication node 100 in step S716, the number of communication nodes belonging to the group to which the first communication node 100 belongs is increased by one.

  In step S720, the first communication node 100 determines whether or not the identifier of the communication node attached to the group information loading message is smaller than the identifier of the first communication node 100 itself. If it is greater than or equal to the identifier of the first communication node 100, the process returns to step S706.

  In step S722, when the identifier is less than the identifier of the first communication node 100 in step S720, the group configuration recognition unit 1068 increments the transmission order of the first communication node 100 by one, and the process returns to step S706.

<Effect of the communication system of the present embodiment>
FIG. 8 shows an example (part 1) of network reconfiguration.

  The left diagram in FIG. 8 shows the network before reconfiguration. The network before reconfiguration is composed of a communication node 1 and a communication node 2.

  A communication node 3 is newly added to the network composed of the communication nodes 1 and 2. Before reconfiguring the network, the communication node 1 sends a message 1 after the time represented by the offset 1 from a certain reference time, and the communication node 2 after the time represented by the offset 2 from the certain reference time. Send message 2. Before reconfiguring the network, message 1 and message 2 do not collide.

  When the network is reconfigured, the transmission timing of the message 3 transmitted by the communication node 3 is designed so as not to collide with the communication message 1 and the communication message 2.

  The right diagram in FIG. 1 shows the network after reconfiguration. The communication node 3 is designed to transmit the message 3 after the time represented by the offset 3 has elapsed from a certain reference time. In the example shown in the right diagram of FIG. 1, the offset 3 is a time between the offset 1 and the offset 2.

  In this way, since the transmission timing offset is set in the newly added communication node 3 so as not to collide with the messages from the communication node 1 and the communication node 2, it takes a design man-hour.

  Depending on an example of network reconfiguration (part 1), when the transmission timing of a newly added communication node cannot be adjusted, it is necessary to change the transmission timing of an existing communication node.

  FIG. 9 shows an example (part 2) of network reconfiguration.

  The left diagram in FIG. 9 shows the network before reconfiguration. The network before reconfiguration is composed of a communication node 1 and a communication node 2.

  A communication node 3 is newly added to the network composed of the communication nodes 1 and 2. Before reconfiguring the network, the communication node 1 sends two messages after the time represented by the offset 1 from a certain reference time, and the communication node 2 passes the time represented by the offset 2 from the certain reference time. Message 2 is sent later. Since the message 2 is transmitted between two messages transmitted from the communication node 1, the message 1 and the message 2 do not collide before the network is reconfigured.

  The middle diagram of FIG. 9 is obtained by applying the method of the example of network reconfiguration (part 1) in the case of the left diagram of FIG. 9 to perform reconfiguration.

  When the method of the example of network reconfiguration (part 1) is applied, the transmission timing of the communication node 3 is designed so as not to collide with the message 1 and the message 2. However, there is no time in which message 3 can be transmitted when there is no collision with message 1 and message 2. That is, the transmission offset of message 3 cannot be set so as not to collide with message 1 and message 2.

  The right diagram in FIG. 9 shows the network after reconfiguration. The transmission timing is changed so that the communication node 2 transmits the message 2 after elapse of the time represented by the offset time 2 ′ from the reference time. In the example shown in the right diagram of FIG. 9, the offset 2 ′ is shifted from the offset 2 to the second transmission time side in the message 1 transmitted from the communication node 1. As described above, when the transmission timing of the communication node 3 cannot be designed so as not to collide with the message 1 and the message 2, the design change is performed by shifting the transmission timing of the message 2, and then the communication node 1 and Since an offset of transmission timing is set so as not to collide with a message from the communication node 2, a cost for design change occurs.

  On the other hand, according to one embodiment of the communication system, when performing time synchronization using an event-driven network, each communication node does not spontaneously collide with other communication nodes other than the own communication node after the start of communication. The transmission timing can be calculated and set. For this reason, when a communication node is newly added to the communication system, setting of transmission timing such as design of offset time of the added communication node and change of transmission timing of an existing communication node can be eliminated.

  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 10 Communication bus 100 1st communication node 102 Transceiver 104 Microcomputer 106 Controller 108 Driver 110 Interface 112 COM
114 Application 200 Second communication node 300 Third communication node 400 Fourth communication node 500 Fifth communication node

Claims (1)

A network control device included in each of a plurality of communication nodes constituting an event-driven network,
After the network is activated, the plurality of communication nodes constitute one or a plurality of groups, and each communication node transmits a message accompanied by an identifier of the communication node and group information to which the communication node belongs,
A network control device mounted on one communication node of the plurality of communication nodes,
Based on the group information to which each communication node belongs and the identifier of each communication node, based on the identifier of the one communication node and the identifier of another communication node other than the one communication node belonging to the group to which the one communication node belongs And a control unit that sets an order of transmission of the one communication node in the group.

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