JP5252374B2 - In-vehicle communication network system - Google Patents

Description

  The present invention relates to an in-vehicle communication network system.

JP 2007-28632 A JP 2004-320423 A JP 2003-124950 A JP 2002-325085 A JP-A-8-191485

  In recent years, many safety and comfort functions are installed in automobiles, and ECUs (electronic control units) that control these individual functions are connected via an in-vehicle network to perform cooperative operation. A typical example of such an in-vehicle network is a CAN (Controller Area Network), which is widely adopted as a standard serial communication network for powertrain, chassis, body, and information systems. CAN is a high-speed communication protocol in which the maximum data transfer rate is defined as 1 Mbps, the physical layer is a two-wire system (three wires including the ground), and the communication distance is a maximum of 1 km. All nodes are in an equal position and any node can be a master node. Although it is asynchronous (start-stop synchronization type), it achieves highly accurate inter-node synchronization such as resynchronization processing by edge detection and bit stuffing. In order to increase the noise margin, a differential transmission method using twisted pair wires is adopted, and in order to realize highly reliable multi-master communication such as bus arbitration and bus state transition using an error counter, Various ideas have been made.

  However, the above-mentioned features of CAN also have a side where network costs are likely to rise. For example, among body equipment classified as body systems, high-speed and detailed control such as electric door mirrors and power windows is possible. As a network for device control that is not so required, there is a drawback that it tends to become excessive specifications. Therefore, in order to make up for this drawback, LIN (Local Interconnect Network) has been proposed as a simple serial communication network, and actual implementation is proceeding (Patent Documents 1 to 5). LIN has a maximum data transfer rate of 19.2 kbps, uses a simple protocol based on half-duplex UART (Universal Asynchronous Receiver Transmitter) communication, and a single master node manages multiple slave nodes. To do. LIN is asynchronous (asynchronous type), similar to CAN, but it is a single master method. In response to this, LIN performs a master task in addition to a simple hardware configuration such as a node configuration by UART and a single wire bus. By adopting a simple synchronization protocol in which a synchronization frame is incorporated in the header and the slave baud rate is corrected by referring to the reference waveform for time correction, a significant cost reduction can be realized compared with CAN although the transmission rate is low.

  By the way, when constructing an in-vehicle communication network, CAN and LIN do not exist independently of each other, but there are overwhelming cases where they coexist on one vehicle. Specifically, a composite network is constructed in such a way that one of the nodes constituting the CAN cluster is used as a gateway and a LIN cluster is connected to the gateway. Since the LIN has a protocol of 1 master + multiple slaves, a system in which a CAN node forming a gateway operates as a LIN master node is generally employed. FIG. 22 shows an actual example in the body-system CAN cluster. The CAN nodes connected by the body-system trunk bus 103 (A), specifically, the body ECU 106 (A) and the A / C (air conditioner) ECU 106 (B). And P / W (power window) ECUs 104 (A) to 104 (D) (“D”, “P”, “RR”, “RL” are “driver's seat”, “passenger seat”, “rear right seat”, respectively. Two LIN clusters are formed with the slave node “indicating“ rear left seat ”).

  In FIG. 22, slave node groups including the same P / WECUs 104 (A) to 104 (D) are provided in a redundant manner corresponding to the body ECU 106 (A) and the A / CECU 106 (B) forming the master node. However, since the same slave node group is provided redundantly, it is difficult to avoid high cost. In this case, if one LIN cluster can be shared between the body ECU 106 (A) and the A / CECU 106 (B), waste can be saved. However, the LIN is a single master system and can be used on one LIN communication bus. It is not allowed in the protocol that there are two master nodes.

  On the other hand, as a connection method for sharing one slave node group by two master nodes without causing protocol inconsistency, a method as shown in FIG. 21 is possible. Here, body system ECU 106 (A) connected to body system main bus 103 (A) serves as one gateway, and travel system ECU 106 (B) connected to travel system dedicated bus 103 (A) serves as the other gateway. In these two gateways, a LIN cluster composed of four slave nodes 104 (A) to 104 (D) is shared. Specifically, the four slave nodes 104 (A) to 104 (D) control the seat ECU 104 (A) that controls the seat position adjusting mechanism and the tilt / telescopic mechanism that adjusts the vertical position or the front / rear position of the handle. It includes a chill tele ECU 104 (B), a pedal adjustment ECU 104 (C) that controls a pedal position adjustment mechanism for an accelerator and a brake, and a seat belt ECU 104 (D) that controls a seat belt position adjustment mechanism.

  Each of the slave nodes 104 (A) to 104 (D) includes two LIN transceivers, and is duplicated by two LIN communication buses 105 (A) and 105 (B) connected to different gateways. Connected. That is, each of the slave nodes 104 (A) to 104 (D) has the first LIN cluster (105 (A)) having the body system ECU 106 (A) as a master node and the traveling system ECU 106 (B) as the master node. It belongs to the second LIN cluster (105 (B)) that overlaps.

  For example, in a scene where user convenience and comfort are prioritized, the seat position, steering wheel position, pedal position or seat belt position is automatically adjusted to the LIN cluster to an appropriate position taking into account the ease of driving and getting on the user. It is preferable to perform control. On the other hand, in a scene where collision safety is important, it is preferable to perform control for automatically adjusting each position to an appropriate position in consideration of shock absorption when a car is likely to hit. However, the sensing infrastructure configuration and scene arrival determination conditions necessary for detecting the arrival of each scene, and the appropriate target position are all different, so the body ECU 106 (A) is used as the master node in the former and the traveling in the latter. The system ECU 106 (B) is used as a master node, and the same slave nodes 104 (A) to 104 (D) need to be dared to be separately controlled via different LIN communication buses.

Which CAN node is to be controlled as the master node for the slave nodes 104 (A) to 104 (D) is determined according to the contents of the incoming scene as described above. However, each of the CAN nodes (106 (A), 106 (B)) forming the gateway is an independent LIN master node, and depending on the scene contents, the plurality of CAN nodes may be the same slave node 104 (A)- It is possible to attempt to control 104 (D) simultaneously (ie, in competition). In this case, it is necessary to mediate which CAN node acquires the authority of the master node according to the contents of the scene. Correspondingly, the following problem occurs.
(1) It is necessary to provide a dedicated communication line for performing the arbitration between the CAN nodes. Even when these CAN nodes are on the same CAN cluster, the arbitration method defined in the CAN protocol is merely a first-come-first-served bus arbitration method based on the CSMA / CA method. Since arbitration is not performed on the basis of arrival, it is necessary to separately install CAN communication software for performing LIN master node arbitration even when a dedicated communication line is provided or not provided.
(2) All physical layers (communication lines and LIN transceivers in the nodes) of the LIN cluster must be made redundant, and the cost merit of the single-wire LIN is significantly hindered.

  An object of the present invention is to provide an in-vehicle communication network system including a LIN cluster in which a master node can be switched at any time without impairing the cost merit of a single-wire LIN.

Means for Solving the Problems and Effects of the Invention

The in-vehicle communication network system of the present invention includes a LIN cluster in which a plurality of LIN nodes are connected by a single LIN communication bus. In order to solve the above problem, two or more LIN nodes forming the LIN cluster are included. Is an attribute switchable node that can be switched between a master node and a slave node, and one of these attribute switchable nodes is the master node of the LIN cluster, and the remaining one is a slave of the LIN cluster. Each node is provided with a master / slave setting switching means for setting each switchable , and a message frame structure for data transmission in LIN communication includes a header transmitted as a master task and a response transmitted as a slave task. , Header transmission and reception and response transmission and reception Communication messages are exchanged in a repetitive manner, and the attribute switchable node has a header sending means for sending the header to the LIN communication bus when operating as the master node, and the response is also sent to the LIN communication bus. Response receiving means for receiving, header receiving means for receiving the header when operating as the slave node, and response sending means for sending the response to the communication bus are also provided .

  In the present invention, in an LIN cluster in which a plurality of LIN nodes are connected by a single LIN communication bus, two or more of the included LIN nodes can be switched between a master node and a slave node. There is provided a master / slave setting switching means for setting any one of these attribute switchable nodes to the master node of the LIN cluster and the remaining nodes to the slave nodes of the LIN cluster to be switchable. . Since the authority of the master node can be transferred at any time between the plurality of attribute-switchable nodes, the LIN node that is the master node can always be maintained at one moment, and does not violate the LIN protocol. Therefore, even though a plurality of LIN nodes that can serve as master nodes are provided for the same slave node group, there is a single LIN communication bus, and wasteful redundancy of the physical layer can be prevented. In addition, it is only necessary to perform arbitration between the attribute-switchable nodes as the master node via the LIN communication bus, so there is no need to provide a new communication line between the attribute-switchable nodes.

  Note that, even if the attribute switchable node is set to either the master node or the slave node, communication within the LIN cluster is performed using the same LIN communication bus, so each LIN including the attribute switchable node is included. The node may be configured as having only one LIN transceiver corresponding to the LIN communication bus. This further enhances the effect of preventing unnecessary redundancy of the LIN physical layer.

  In LIN communication, a message frame structure for data transmission is defined by a protocol. The message frame structure for data transmission in LIN communication is composed of a header transmitted as a master task and a response transmitted as a slave task. In the LIN protocol, communication messages are alternately repeated between header transmission and reception and response transmission and reception. Is exchanged. In the present invention, each attribute-switchable node includes a header sending means for sending a header to the LIN communication bus when operating as a master node, a response receiving means for receiving a response, and a header when operating as a slave node. Header receiving means for receiving, and response sending means for sending a response to the communication bus. In other words, since the conventional LIN node is fixedly set to either the master node or the slave node, only the header transmission means and the response reception means for the master node, and the header reception means and the response transmission for the slave node. Only means were provided. However, the attribute-switchable node of the present invention has all the above four means related to the transmission and reception of headers and responses, so that it can be switched at any time to either the master node or the slave node while being the same LIN node. It becomes possible.

  The master node authority transfer, that is, the node attribute switching mode, is that the master node authority from the attribute switching type node that is currently the master node to the other attribute switching type node that is currently the slave node Delegation-type transfer pattern for requesting delegation and request-type transfer in which an attribute switchable node that is currently a slave node requests the transfer of master node authority to another attribute switchable node that is currently a master node There are two types of patterns. In either case, the master node authority is actually transferred after obtaining the consent of the partner node to which the delegation or request is made. However, in the LIN based on the protocol of the message structure based on the header / response in which the slave node responds to the header from the master node as a response, a series of node attribute switching processing based on the LIN communication is performed by the slave. There is a request that must be terminated by sending a response from the node to the master node. Considering this point, the delegation-type transfer pattern in which the start side of the node attribute switching process is the master node has a simpler communication sequence, and the communication sequence of the request-type transfer pattern is a form that develops the communication sequence of the delegation-type transfer pattern. You can build with. This will be specifically described below.

First, in order to realize the delegation type transfer pattern, it is necessary to provide the following means for each attribute switchable type node.
-Master authority transfer offer notification means: When the switching condition is satisfied in the state set in the master node, it is associated with the switching condition among the other attribute switchable nodes set in the slave node. A master authority delegation notification for requesting master authority delegation to a designated one is performed via the LIN communication bus. This notification is made by sending a header from the master node according to the LIN protocol.
Master switching control means: When a master authority delegation notification is received in the state set in the slave node, it is determined whether or not to accept the master authority, and the determination result is returned. This reply is made by sending a response from the slave node according to the LIN protocol. Then, when it is determined to accept the authority, its own node setting is switched from the slave node to the master node (internal processing in the slave node).
・ Slave switching control means: When the above determination result is received in a state where the master node is set, and the determination result is affirmative with respect to authority acceptance, the own node setting is changed from the master node to the slave node. Switch (this is internal processing at the master node).

Now, in the LIN message structure, it is a protocol requirement to incorporate the following three fields as essential fields in the header.
Break field (Sync Break): indicates the start of a message. That is, it is an area transmitted by the master task for the purpose of notifying the start of the LIN message frame.
Sync field: A time correction reference waveform is incorporated. That is, a slave node that requires clock accuracy is an area for clock correction.
Identifier field (Ident Field): specifies a slave node as a communication destination. That is, this is an area for designating a slave task to which the master task sends a response.

Also, in the response, it is a protocol requirement to incorporate the following two fields as essential fields.
Data field (Data Field): The data to be transmitted is incorporated as it is designated as the communication destination by the identifier field of the header. That is, this is an area for the slave task to notify the master task of data.
Error check field (Check Sum): An area for determining whether the response of the slave task is normal or abnormal. Abnormality determination is performed by checksum.

On the other hand, the LIN protocol prohibits the above fields from being missing from the header or response, but does not specifically prohibit the inclusion of other fields. In the delegation-type transfer pattern, the master node authority is delegated from the master node side, and the master node authority delegation notification is sent by sending a header. Therefore, a new field is provided in the header for performing this delegation application notification. As a result, master authority delegation offer notification can be made consistent with the LIN protocol. Specifically, the following additional fields are incorporated into the header.
Delegation field: Specifies whether or not the attribute-switchable node serving as the master node performs master authority delegation. That is, this is an area where the master node delegates the authority of the master to the slave node (hereinafter also referred to as “Deletion_1 Field”).

In addition, in the slave node that is the target of the master authority delegation offer, by providing a new field in the response for notifying the master node of the determination result of whether or not to accept the offer from the master node by the delegation field, It becomes possible to notify whether or not to accept the delegation of master authority while conforming to the LIN protocol. Specifically, the following additional fields are included in the response.
Delegation approval field: Specifies whether or not the attribute switchable node serving as the slave node approves the master authority delegation indicated by the delegation field of the header. For example, it can be configured as an area (Slave Error Field) for returning error response contents for master authority delegation from the master node.

  When a plurality of slave nodes are included in the LIN cluster, the master node can exchange messages using headers / responses in a specified order with respect to each slave node by a so-called polling method. When the polling method is adopted, first, a communication order for prescribing a predetermined polling cycle is uniquely assigned to a plurality of LIN nodes including an attribute switchable node. When each attribute switchable node is set as a master node, the header transmission means and the response reception means send the header on the LIN communication bus to the response from the corresponding slave node. While alternating with reception, the slave node as the communication destination is repeatedly changed in accordance with the polling cycle.

  When the polling method is adopted in the present invention, the communication rank is given to all nodes including the attribute switchable node in the LIN cluster. On the other hand, the present invention is characterized in that a master node can be switched between a plurality of attribute switchable nodes in the same LIN cluster. Even when such a master node change occurs, it is desirable to maintain the fairness of participation of each slave node in the communication sequence so that the communication sequence according to the polling cycle is maintained as much as possible. .

  For example, with a master node that is a master authority delegation source as a delegation source node and a slave node that is a master authority delegation destination as a delegation destination node, in the delegation-type transfer pattern, the delegation source node communicates with the delegation destination node in the polling cycle. As the order arrives, a header in which the contents specifying the delegation destination node as the master authority delegation destination in the delegation field is transmitted as the delegation destination designation header. The delegation destination node receives the delegation destination designation header and determines whether or not to approve the delegation of the master authority, and if so, approves the response following the delegation destination designation header and approves the master authority delegation in the delegation approval field. Is sent as a delegation approval response describing the contents to be performed, and the own node is switched to the master node and set. In addition, the delegation source node receives the delegation approval response and switches its own node to the slave node. In this case, if it is determined that the master node after switching starts transmission of the header in the form of updating the polling cycle from the slave node whose communication order is determined next to its own node, the master node before switching The polling cycle can be taken over smoothly.

  On the other hand, when the master node is not switched, that is, after the delegation destination node receives the delegation destination designation header and does not approve the delegation of the master authority, the delegation destination node responds following the delegation destination designation header. Is described in the delegation approval field, the content not approving the master authority delegation is described and transmitted as a delegation non-approval response, and the own node is set and maintained in the slave node. On the other hand, the delegation source node receives the delegation non-approval response and sends the header specifying the slave node of the next rank of the delegation destination node while maintaining its own node as the master node. As a result, the polling cycle can be continued without causing any disturbance.

Next, in order to realize the request type transfer pattern, it is necessary to provide the following means for each attribute switchable type node.
Master delegation request notifying means: Master authority delegation that requests master authority delegation to other attribute switchable nodes set in the master node when the switching condition is satisfied in the state set in the slave node Request notification is performed via the LIN communication bus. This notification is made by sending a response from the slave node according to the LIN protocol.
Slave switching control means: When a master delegation request notification is received in a state set in the master node, it is determined whether to accept the delegation of the requested master authority, and the determination result is returned. This reply is made by sending a header from the master node. Then, when accepting the delegation, its own node setting is switched from the master node to the slave node (internal processing in the master node).
Master switching control means: When the above determination result is received in a state where the slave node is set, and the determination result is affirmative with respect to delegation of master authority, the own node setting is set from the slave node. Switch to master node (internal processing at slave node).

  Thus, in the request type transfer pattern, the communication sequence directly involved in the transfer of the master node authority is started from the response transmission of the slave node (attribute switchable type node) forming the delegation destination node. However, after that, a header (delegation field) for requesting transfer of master node authority from the delegation source node that approved the request follows, and the communication sequence is a response (delegation approval field) that the delegation destination node accepts the offer. Complete. That is, the communication sequence in the request type transfer pattern has a structure in which a response for the authority request is added prior to the header / response that forms the main part of the communication sequence in the delegation type transfer pattern.

That is, in the request-type transfer pattern, the master node authority is requested to be delegated from the slave node side, and the master node authority delegation request is made by sending a response. Therefore, a new field for making this delegation request is used as a response. By providing, it becomes possible to make a master authority delegation request consistent with the LIN protocol. Specifically, the following additional fields are included in the response.
Delegation request field: Specifies whether or not to request master authority delegation to an attribute switchable node that becomes a master node. In other words, this is an area for issuing a request to become a master node from a slave node (hereinafter also referred to as “Delegation_2 Field”).

In addition, in the master node that is the target of the master authority delegation request, a new field is provided in the header for notifying the master node of the determination result of whether or not to accept the request from the slave node by the delegation request field. Thus, it is possible to notify whether or not to accept the master authority delegation request while conforming to the LIN protocol. Specifically, the following additional fields are incorporated into the header.
Delegation request approval field: Specifies whether or not the attribute switchable node serving as the slave node approves the master authority transfer request. For example, it can be configured as an area (Master Error Field) for returning an error response content to a master authority delegation request from a slave node.

  In the request-type transfer pattern, the delegation destination node sends a response in which a request in which the delegation destination node is a master authority delegation destination is described in the delegation request field as a delegation destination designation response, and the delegation source node sends the delegation destination designation response To determine whether to approve the delegation of master authority. Then, when the delegation source node approves the delegation, when the same sequence as the delegation type transfer pattern is adopted, the master node replacement timing is determined so that the communication order of the delegation destination node to be the next master node is already Since the time has passed, there is a waiting time of about one polling cycle until the communication order of the delegation destination node comes next. Of course, this method can also be employed in the present invention, but the following method is suitable for more quickly changing the master node.

  That is, when the delegation source node approves the delegation, the delegation source node that is currently the master node stops the polling cycle once it receives the delegation destination designation response from the delegation destination node. Then, the header following the delegation destination designation response is described in the delegation request approval field, the contents for approving the master authority delegation request, and in the delegation field, the header describing the contents for designating the delegation destination node as the master authority delegation destination As the delegation destination designation header, the polling cycle is restarted from the delegation destination node. That is, only in this case, the polling cycle is continued by repeating the communication order of the delegation destination node that should have already passed once. Thereby, shortening of said waiting time can be aimed at. After that, the delegation destination node receives the delegation destination designation header and determines whether or not to approve the delegation of master authority. If so, the response following the delegation destination designation header is transferred, and the master authority delegation is transferred to the delegation approval field. Is sent as a delegation approval response that describes the content to approve, and the own node is switched to the master node and the header is newly sent in the form of taking over the polling cycle from the slave node whose communication order is set next to the own node Start. In addition, the delegation source node receives the delegation approval response and switches its own node to the slave node.

  If the delegation source node receives the delegation destination designation response and rejects the master authority delegation request, describe the header following the delegation destination designation response and the contents to deny the master authority delegation request in the delegation request approval field. The delegation request rejection header is transmitted, the own node is set and maintained as the master node, and the polling cycle is continued by sending a header designating the slave node of the next rank of the delegation destination node. As a result, the polling cycle can be continued without causing any disturbance.

  If you want to build a message frame that can handle both delegation-type transfer patterns and request-type transfer patterns, both a delegation field and a delegation request approval field are included in the header, and a delegation approval field and a delegation request field are included in the response. Both will be provided. Each field of the header and response can be identified by fixing the position of the header or response from the beginning and the field length so that each field can be identified as long as the start and stop bits can be identified. Even if this area is not provided, it is possible to identify which field is currently being received on the receiving side without any problem.

  Next, in the in-vehicle communication network system of the present invention, a CAN cluster in which a plurality of CAN nodes are connected by a CAN communication bus, a plurality of LIN nodes are connected by a single LIN communication bus, and the CAN node is used as a gateway node. It can be configured as a composite in-vehicle communication network system composed of LIN clusters connected to CAN clusters. A plurality of CAN nodes can be used as gateway nodes, and one LIN communication bus constituting the LIN cluster can be distributed and connected to the plurality of gateway nodes, and each gateway node can be configured as an attribute-switchable node. .

  A configuration in which a CAN node is used as a gateway and this is operated as a LIN master node is simple and inexpensive in design, and if there are the necessary number of communication channels and CPU performance for the microcomputer used, a plurality of LIN communications can be performed on one gateway. Since the design to connect the bus is easy, it is widely used as a typical infrastructure form for in-vehicle communication network systems. However, this method is one of the major drawbacks when a CAN node serving as a gateway fails, the entire LIN cluster connected thereto may go down. For example, when all functions of a LIN node operate subordinately only with a command from a CAN cluster as a connection destination, in particular, when a target LIN cluster is functionally closed by itself (for example, The function that the switch and the lamp are connected to the slave node and the lamp is turned on when the switch is turned on) is functionally meaningless if the gateway fails, even if all other slave nodes are normal. In addition, the in-vehicle functions that the LIN cluster is responsible for may be lost at once.

  On the other hand, as a method that can protect the LIN cluster from the troubles of the gateway as described above, a method of operating a CAN node as a gateway as a LIN slave node has been put into practical use. For example, in LIN2.0, the disconnection of a failed node is defined by a protocol, and the reliability almost equal to that of CAN can be ensured for a gateway failure. However, since the gateway acts as a LIN slave node, the master node in the LIN cluster (which does not form a gateway) polls the LIN slave node that forms the gateway periodically to check messages from the CAN cluster side. There is a problem that requires additional functionality.

  In LIN, a simple synchronization protocol is adopted in which a synchronization frame is incorporated in a header constituting a master task, and a slave baud rate is corrected by referring to the time correction reference waveform. That is, every time data is transmitted, the slave node corrects the baud rate in accordance with the time correction reference waveform from the master node, and synchronizes. On the other hand, CAN is a multi-master serial communication protocol that can cope with a relatively high transmission rate, and has a more accurate inter-node synchronization mechanism such as resynchronization processing by edge detection and bit stuffing. Therefore, if a CAN node with high synchronization accuracy is adopted as a master node in the LIN cluster, the synchronization accuracy in the LIN cluster can be improved. However, if the CAN node is used as a slave node, it is difficult to achieve the same synchronization accuracy as long as the LIN master node separated from the CAN communication bus is adopted, even if it can be realized. Therefore, it is inevitable to increase the cost, such as higher performance of the oscillation circuit of the LIN master node and complicated synchronization method.

  However, as in the present invention, one LIN communication bus that constitutes a LIN cluster is distributed and connected to a plurality of gateway nodes that form CAN nodes, and each gateway node can be switched between attributes to enable master / slave switching. By configuring, even if the attribute switchable node that is currently the master node goes down, another live attribute switchable node can be switched to the master node. As a result, the fail-safe function of the LIN cluster is remarkably improved, and the reliability can be dramatically increased. In addition, since any attribute-switchable node that can be a master node is a CAN node, it is easy to ensure synchronization accuracy in the LIN cluster.

  The master / slave setting switching unit has a communication state monitoring unit that monitors the communication state of the CAN cluster or the LIN cluster, and can switch a plurality of attributes when a predetermined switching condition is satisfied in the communication state being monitored. It can be configured to switch the setting of the master node and the slave node in the type node. The communication state being monitored, that is, a node suitable for a scene among a plurality of attribute-switchable nodes can be switched to the master node at any time, and finer control is possible. In this case, for each predetermined type of communication state (scene), a priority order for setting a plurality of attribute switchable nodes as a master node can be determined, and master / slave setting switching means is established. The master node and the slave node can be switched based on the priority order corresponding to the communication state (scene). By determining the priority order for setting a master node for each scene, the master node switching determination algorithm can be greatly simplified.

  The plurality of gateway nodes to which the LIN communication bus is distributed and connected can be distributed and provided to a plurality of CAN clusters forming different control systems. The communication status monitoring means can be configured to monitor the control status of the corresponding control system based on the communication information acquired by each CAN cluster via the CAN communication bus, and the master / slave setting switching means can control the control status being monitored. When a predetermined switching condition is established, a gateway node belonging to a CAN cluster designated in advance in association with the control state can be set as a master node. By sharing one LIN cluster among CAN clusters having different control purposes, it is possible to remarkably expand the scenes to which the in-vehicle functions applied by the LIN cluster are applied, and to further effectively use the LIN cluster.

  On the other hand, one of the plurality of gateway nodes to which the LIN communication bus is distributed and connected is defined as a regular master node of the LIN cluster, while a slave node constituting the remaining gateway node is defined as at least a part of the function of the regular master node. It can also be determined as an alternative master node candidate that can be taken over. The communication status monitoring means monitors the operation status of the regular master node based on the communication information acquired by each CAN cluster via the CAN communication bus. The master / slave setting switching means is used to monitor the regular master node being monitored. When an abnormality having a predetermined content is detected in the operation state, a slave node that is an alternative master node candidate is set and switched to a master node. As a result, even if the regular master node of the LIN cluster goes down, the takeover by the alternative master node can be performed quickly, and the fail-safe function can be significantly improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration example of an in-vehicle communication network system according to the present invention. This in-vehicle communication network system 1 includes a LIN cluster 50 in which a plurality of LIN nodes 4 (A) to 4 (D), 6 (A), and 6 (B) are connected by a single LIN communication bus 5. Two or more of the LIN nodes 4 (A) to 4 (D), 6 (A), and 6 (B) forming the LIN cluster 50, that is, in this embodiment, the nodes 6 (A) and 6 (B). Are the attribute-switchable nodes 6 (A) and 6 (B) that can be switched between the master node and the slave node. Any one of these attribute-switchable nodes 6 (A) and 6 (B) is set to be a switchable node to the master node of the LIN cluster 50, and the remaining ones to the slave nodes of the LIN cluster 50.

  In the configuration of FIG. 1, a plurality of CAN nodes (2 (A), 6 (A)..., 2 (B), 6 (B)...) Are respectively connected to CAN communication buses 3 (A) and 3 (B). To form CAN clusters 100 (A) and 100 (B). Of these, the CAN nodes 6 (A) and 6 (B) are used as gateway nodes (hereinafter also referred to as gateway nodes 6 (A) and 6 (B)), and the LIN cluster 50 is connected to the CAN clusters 100 (A), 100 (B), a composite in-vehicle communication network system is configured. The single LIN communication bus 5 constituting the LIN cluster 50 is distributedly connected to the plurality of gateway nodes 6 (A) and 6 (B), and each gateway node 6 (A) and 6 (B) has attributes. It is configured as a switchable node.

  Of the LIN nodes 4 (A) to 4 (D), 6 (A), and 6 (B), the remaining 4 (A) to 4 (A) to 4 (A) to 4 (A) to 4 (A) are excluded except for the attribute switchable nodes 6 (A) and 6 (B) (D) can function only as a slave node of LIN. As shown in FIG. 2, each has a UART controller 41 mainly composed of, for example, an 8-bit microcomputer (or a 16-bit microcomputer), The LIN transceiver 42 is connected to the LIN communication bus 5 made of a single metal wire.

  On the other hand, of the CAN nodes (2 (A), 6 (A)... And 2 (B), 6 (B)...), The remaining ones except for the attribute switchable nodes 6 (A) and 6 (B). As shown in FIG. 2, each of the products 2 (A) and 2 (B) has a CAN controller 41 mainly composed of, for example, a 32-bit microcomputer (may be a 16-bit microcomputer or an 8-bit microcomputer), and a CAN transceiver 42 is provided. To the CAN communication bus 3 including a twisted pair line.

  Each of the gateway nodes 6 (A) and 6 (B) has a CAN / LIN gateway processor 61 mainly composed of, for example, a 32-bit microcomputer, and is further connected to the CAN communication bus 3 via the CAN transceiver 22. 42 to the LIN communication bus 5.

  In the present invention, the CAN / LIN gateway processor 61 operates as software such as data buffering, timing control, and protocol conversion between LIN and CAN in addition to operating as a LIN master node, a LIN slave node, and a CAN node. Necessary. FIG. 3 illustrates the main software modules required along with their interrelationships.

LIN driver 609: software for realizing LIN communication. It has a master driver 622 for operating as a LIN master node, a slave driver 623 for operating as a LIN slave node, and an attribute switching unit 621. The attribute switching unit 621 transmits the message via the message scheduler 607. Then, either the master driver 622 or the slave driver 623 is operated according to the description content of the LIN message frame (header or response) described later. As a result, communication is performed while controlling the UART, timer, etc. in the microcomputer as either the LIN master node or the LIN slave node.
CAN driver 610: Software for realizing CAN communication. It communicates by controlling the CAN controller in the microcomputer.

ID mapping table 606 / message filter 603: Controls protocol conversion. The ID mapping table 606 stores ID (identifier) conversion information of LIN and CAN. When the ID requires gateway communication, the message filter 603 converts the CAN protocol ID and the LIN protocol ID according to the ID mapping table 606. In addition, message transmission / reception requests are stored in the LIN message buffer 604 and the CAN message buffer 605.
Error handler 608: Controls error control. Error processing including errors from the LIN driver 609, the CAN driver 610, or the gateway itself is performed.

LIN message buffer 604 / CAN message buffer 605: It manages data buffering. It consists of a FIFO (first-in first-out) ring buffer and stores message transmission / reception requests to the LIN or CAN. It is composed of independent buffers for LIN and CAN.
Message scheduler 607: It manages timing control and provides a timing function for inquiring each message buffer 604, 605. Also, a transmission / reception request is acquired from the LIN message buffer 604 or the CAN message buffer 605, and the transmission / reception data is transferred to the LIN driver 609 and the CAN driver 610.

Gateway API (Application Programming Interface) 602: In addition to data forwarding from each node, the gateway itself has a transmission / reception function. The basic API is, for example, a transmission request to the CAN network, a reception request to the CAN network (above master / slave common), a reception request to the LIN master node (header reception + response transmission: when functioning as a slave node), LIN It consists of a transmission request to the slave node (only header transmission), a reception request from the LIN slave node (header transmission + response reception), LIN sleep command transmission, LIN wakeup transmission (when functioning as a master node).
User application 601: As will be described later, it administers a master / slave switching command corresponding to a scene and a higher-level control command at each slave node.

  In the system configuration of FIG. 1, the gateway nodes to which the LIN cluster 50 is connected are the body system ECU 6 (A) and the travel system ECU 6 (B), and these gateway nodes are respectively different CAN clusters as attribute-switchable nodes. It is provided on 100A and 100B. A single LIN communication bus 5 constituting the LIN cluster 50 is distributedly connected to these two gateway nodes 6 (A) and 6 (B), and four slave nodes 4 (A) to 4 (D) are connected to the CAN. It is shared by the clusters 100A and 100B.

  Specifically, the four slave nodes 4 (A) to 4 (D) control the seat ECU 4 (A) that controls the seat position adjusting mechanism and the tilt / telescopic mechanism that adjusts the vertical position or the front / rear position of the handle. It includes a tilt tele ECU 4 (B), a pedal adjustment ECU 4 (C) that controls a pedal position adjustment mechanism for an accelerator and a brake, and a seat belt ECU 4 (D) that controls a seat belt position adjustment mechanism.

  In a scene where user convenience and comfort are prioritized, the LIN cluster 50 automatically adjusts the seat position, the handle position, the pedal position, or the seat belt position to an appropriate position in consideration of the user's ease of driving and boarding. Take control. On the other hand, in a scene where collision safety is important, control is performed to automatically adjust each position to an appropriate position in consideration of shock absorption when a car is likely to hit. In the former, the body ECU 6 (A) is a master node and the traveling ECU 6 (B) is a slave node as shown in FIG. 4, and in the latter, the traveling ECU 6 (B) is as shown in FIG. Is the master node, and the body ECU 6 (A) is the slave node, and control is performed while switching the node attributes. Hereinafter, when it is necessary to display the node attribute setting status separately, "'(dash)" is added to the gatewayed code set for the slave node, and the gatewayed set for the master node. By not attaching “'(dash)” to the reference numeral, they are displayed separately.

  Each gateway node 6 (A), 6 (B) configured as an attribute switchable node includes both a master driver 622 and a slave driver 623 as shown in FIG. 2 (for example, the slave in FIG. 1). The nodes 4 (A) to 4 (D) are provided with only the slave driver 623. When operating as a master node, the header of the LIN message frame is sent (header sending means) and the response is received (response reception). means). On the other hand, when operating as the slave node 4, the header is received (header receiving means) and the response is sent (response sending means).

There are the following two types of node attribute switching patterns between the gateway nodes 6 (A) and 6 (B), that is, master node authority transfer patterns.
Delegation-type transfer pattern: For the gateway node (the body system ECU 6 (A) ′ in FIG. 4) that the gateway node (the traveling system ECU 6 (B) in FIG. 4) is the current slave node. Apply for delegation of master node authority from yourself.
Request type transfer pattern: The gateway node (body ECU 6 (A) ′ in FIG. 4) that is currently a slave node is changed to the gateway node (travel ECU 6 (B) in FIG. 4) that is currently the master node. Request surrender of master node authority. In either case, the master node authority is actually transferred after obtaining the consent of the partner node to which the delegation or request is made.

  The LIN protocol is basically based on a message frame structure in which a slave node returns a response to a header from a master node. Therefore, there is a request that the sequence related to the node attribute switching process must be terminated by sending a response from the slave node to the master node.

In the present invention, as shown in FIG. 7, by incorporating a new field for realizing a master authority transfer sequence in the LIN message structure while maintaining a field essential for the protocol, the master / master of the same node is incorporated. Slave attribute switching is realized. The following fields are provided in the header. All fields except for the start bit and stop bit,
Break field (Sync Break): An area transmitted by the master task for the purpose of notifying the start of the LIN message frame.
Synchronization field (Sync Field): An area for a slave node that requires clock accuracy to perform clock correction.
Identifier field (Ident Field): This is an area for the master task to specify a slave task that performs response transmission.
Delegation field (Delegation_1 Field): specifies whether or not the gateway node serving as a master node performs master authority delegation. That is, this is an area where the master node delegates the authority of the master to the slave node.
Delegation request approval field (Master Error Field): Specifies whether or not the attribute switchable node serving as the slave node approves the master authority transfer request. It is configured as an area that returns error response contents for master authority delegation requests from slave nodes.

Also, in the response, it is a protocol requirement to incorporate the following two fields as essential fields.
Data field (Data Field): The data to be transmitted is incorporated as it is designated as the communication destination by the identifier field of the header. That is, this is an area for the slave task to notify the master task of data.
Error check field (Check Sum): An area for determining whether the response of the slave task is normal or abnormal. Abnormality determination is performed by checksum.
Delegation approval field (Slave Error Field): Specifies whether or not the gateway node serving as the slave node approves the master authority transfer indicated by the delegation field of the header. It is configured as an area for returning error response contents for master authority delegation from the master node.
Delegation request field (Delegation_2 Field): specifies whether or not to request master authority delegation to the gateway node as the master node. That is, it is an area for issuing a request to become a master node from a slave node.

  That is, in contrast to the conventional LIN message frame structure shown in FIG. 7, in this embodiment, a delegation field (Delegation_1 Field) and a delegation request approval field (Master Error Field) are included in the header, and a delegation approval field (Slave Error). A unique message frame structure in which a field) and a delegation request field (Delegation_2 Field) are respectively added to the response is adopted, and thereby, both a delegation type transfer pattern and a request type transfer pattern can be supported.

  Since the structures of the break field, the synchronization field, the identifier field, the data field, and the error check field are well known, detailed description thereof will be omitted. On the other hand, examples of the configuration of four new fields unique to the present invention are shown in FIGS. In any field, a start bit is given at the beginning and a stop bit is given at the end, as in the known field.

  FIG. 8 shows a configuration example of the delegation field (Delegation_1 Field), and each of a predetermined number of bits (4 in this embodiment) that specifies the ID of the delegation source node (master) and the delegation destination node (slave). Bit) code area is formed.

  FIG. 9 shows an example of the configuration of a delegation request approval field (Master Error Field). As an error response content to a master authority delegation request from a slave node, a predetermined number of bits that specify an error type (8 bits in this embodiment). ) Code region is formed. The error type identification code described in the area is described so that the approval and non-approval of the “master authority delegation request” can be distinguished from each other (for example, when the specific bit (for example, the first bit (ID0)) is “1”. (“Approve”, “0” means non-approval, etc. At this time, the remaining bits can be freely used for description of error details, etc.).

  FIG. 10 shows an example of the configuration of a delegation approval field (Slave Error Field), and a predetermined number of bits (8 bits in this embodiment) that specify an error type as an error response content to the master authority delegation offer from the master node. The code region is formed. The error type identification code described in the area is described so that the approval and non-approval of “master authority transfer offer” can be distinguished from each other (for example, when the specific bit (for example, the first bit (ID0)) is “1”. (“Approve”, “0” means non-approval, etc. At this time, the remaining bits can be freely used for description of error details, etc.).

  FIG. 11 shows an example of the configuration of the delegation request field (Delegation_2 Field), and each of a predetermined number of bits (in this embodiment, each identifying the delegation source node (master) ID and delegation destination node (slave) ID). (4 bits) code area is formed.

  Hereinafter, a specific operation mode of the in-vehicle communication network system 1 of FIG. 1 will be described. Referring to FIG. 6, when the body system ECU 6 (A) is set as a master node, the master node 6 (A) includes a plurality of slave nodes 4 (A) to 4 in the LIN cluster 50. For (D) and 6 (B) ′, messages are exchanged sequentially by header / response in the order specified by the polling method. Specifically, a communication order for defining a polling cycle for a plurality of LIN nodes 6 (A), 6 (B), 4 (A) to 4 (D) including a gateway node (attribute switchable type node). (For example, 6 (A) → 6 (B) → 4 (A) → 4 (B) → 4 (C) → 4 (D) (→ 6 (A)): , Hereinafter referred to as the base cycle). When each gateway node 6 (A), 6 (B) is set as a master node (for example, 6 (A)), the gateway node 6 (A), 6 (B) polls what is excluded from the base cycle. As a cycle (6 (B) → 4 (A) → 4 (B) → 4 (C) → 4 (D) (→ 6 (B)), the transmission of the header on the LIN communication bus 5 While repeating the reception of the response from the node, the slave node as the communication destination is repeatedly changed in accordance with the polling cycle.

  In the LIN cluster 50, the LIN nodes 4 (A) to 4 (D) other than the gateway nodes 6 (A) and 6 (B) are shared by the gateway nodes 6 (A) and 6 (B) as described above. In this case, in this case, of the two gateway nodes 6 (A) and 6 (B), the main gateway that normally serves as the master node for the LIN nodes 4 (A) to 4 (D) The node 6 (A) and the sub-gateway node 6 (B) that becomes a master node only when a predetermined master authority transfer condition is established can be determined. Then, it is determined on the side of the secondary gateway node 6 (B) whether or not the master authority transfer condition is satisfied. If it is satisfied, a request for delegating the master authority from the secondary gateway node 6 (B) to the main gateway node 6 (A). When the master authority is transferred to the secondary gateway node 6 (B) by the request type transfer pattern for performing the master authority transfer condition and then the established state of the master authority transfer condition is canceled, the secondary gateway node 6 (B) to the primary gateway node 6 If the master authority is returned from the secondary gateway node 6 (B) to the primary gateway node 6 (A) by the delegation-type transfer pattern in which the master authority delegation application is performed in (A), smoother control becomes possible. .

  For example, in the example shown in FIG. 4, four slave nodes 4 (A) to 4 (D) are provided with a seat position adjusting mechanism, a tilt / telescopic mechanism for adjusting the vertical position or front / rear position of the steering wheel, and the accelerator / brake pedal position. Each control ECU of the adjustment mechanism and the seat belt position adjustment mechanism is configured. These mechanisms are functions that are normally required to adjust the seat position, handle position, pedal position, or seat belt position to an appropriate position in consideration of ease of driving and boarding by the user (that is, This corresponds to a scene where user convenience and comfort are prioritized). Therefore, the body system ECU 6 (A) is determined as the main gateway node, and normally serves as a master node for the four slave nodes 4 (A) to 4 (D), and supervises the upper control of each mechanism. The body system ECU 6 (A) acquires appropriate values related to the seat position, the handle position, the pedal position, or the seat belt position from the other CAN nodes 2 (A)... Constituting the CAN cluster 100 (A) of FIG. Alternatively, based on output information of a sensor group that measures the user's body size (also acquired from the CAN cluster 100 (A)), appropriate locations at the respective positions are autonomously created, and LIN communication is performed. Transmit to slave nodes 4 (A) to 4 (D).

  On the other hand, the traveling ECU 6 (B), which is normally a slave node, is determined as a sub-gateway node and receives collision information (for example, a collision) from other CAN nodes 2 (B) constituting the CAN cluster 100 (B). The output value of the acceleration sensor for detection) is acquired to determine the presence or absence of a collision. If it is determined that there is a collision, control for adjusting the seat position, the handle position, the pedal position, or the seat belt position to an appropriate position in consideration of shock absorption when the car is likely to hit is performed by the slave node 4 ( Implement in an emergency response via A) to 4 (D). In this case, the traveling system ECU 6 (B) can function as a master node for the slave nodes 4 (A) to 4 (D) by temporarily taking over the master authority from the traveling system ECU 6 (B). .

  FIG. 12 shows a polling sequence in this case, where the traveling system ECU 6 (B) is the delegation destination node and the body system ECU 6 (A) is the delegation source node. First, the traveling system ECU 6 (B) describes a request to make itself a master authority delegation destination in the delegation request field (Delegation_2 Field: FIG. 11) in response to the preceding header HP from the body system ECU 6 (A). Is sent as a delegation destination designation response RB. The body ECU 6 (A), which is the delegation source node, receives the delegation destination designation response RB and determines whether or not to approve the delegation of the master authority (because it has urgency in the case of collision, the traveling system It is desirable that the master authority delegation request from the ECU 6 (B) is accepted in the form of the highest priority).

  When the body system ECU 6 (A) (delegation source node) approves the delegation, the body system ECU 6 (A), which is the current master node, performs a polling cycle from the traveling system ECU 6 (B) (delegation destination node). Once the delegation destination designation response RB is received, it is terminated once. Then, in the header following the delegation destination designation response RB, the contents for approving the master authority delegation request (that is, the content of the error type identification code = “normal”) are described in the delegation request approval field (Master Error Field: FIG. 9). In addition, in the delegation field (Delegation_1 Field: FIG. 8), the contents specifying the traveling system ECU 6 (B) as the master authority delegation destination (and the body system ECU 6 (A) as the master authority delegation source) are described. This is sent out as a delegation destination designation header HA. The traveling system ECU 6 (B), which is the delegation destination node, receives the delegation destination designation header HA, determines whether or not to approve delegation of master authority, and if so, a response following the delegation destination designation header HA In the delegation approval field (Slave Error Field: FIG. 10), the contents for approving the master authority delegation (contents of error type identification code = “normal”) are described and transmitted as a delegation approval response RA and the own node Switch to the master node. Then, the header transmission is newly started in the form of taking over the polling cycle from the slave node (the seat ECU 2 (A) in FIG. 12) whose communication order is determined next to the own node. On the other hand, the body ECU 6 (A), which is the delegation source node, receives the delegation approval response RA and switches and sets its own node to the slave node.

  When the body ECU 6 (A) (delegation source node) receives the delegation destination designation response RB and rejects the master authority delegation request, the header following the delegation destination designation response RB as shown in FIG. Is transmitted as a delegation request rejection header HA ′ in which the content for rejecting the master authority delegation request (the content of the error type identification code = “abnormal”) is described in the delegation request approval field. Then, the own node is set and maintained as the master node, and the slave node (in FIG. 13) of the next rank of the traveling system ECU 6 (B) (which is a “delegation destination node” as a request but is not actually delegated authority) The polling cycle is continued by sending out a header designating the seat ECU 2 (A). Eventually, it can be seen that the polling cycle is continued without causing a jump or duplication of communication order.

  In this state, when the collision detection state is canceled and the collision corresponding control of the seat position, the handle position, the pedal position, and the seat belt position is not necessary, the host control related to the slave nodes 4 (A) to 4 (D). It is necessary to promptly return the main body, that is, the master node to the body system ECU 6 (A) that is the main gateway node as usual. Since the traveling system ECU 6 (B) continues to detect the collision, when the collision detection state is resolved, the traveling system ECU 6 (B) becomes the delegation source node and the body system ECU 6 (A) becomes the delegation destination node. The master authority is transferred / returned to the body system ECU 6 (A) by the delegation-type transfer pattern.

  FIG. 12 shows a polling sequence in this case. The traveling system ECU 6 (B), which is the delegation source node, enters the body in the delegation field (Delegation_1 Field: FIG. 8) as the communication order of the body system ECU 6 (A), which is the delegation destination node, arrives in the polling cycle. The contents specifying the system ECU 6 (A) as the master authority delegation destination (and the traveling system ECU 6 (B) as the master authority delegation source) are described, and this is transmitted as the delegation destination designation header HA. The body system ECU 6 (A) receives the delegation destination designation header HA and determines whether or not to approve the delegation of the master authority, and if so, in the response following the delegation destination designation header HA, the delegation approval field ( In Slave Error Field: FIG. 10), the content for authorizing master authority delegation (error type identification code content = “normal”) is described, and this is transmitted as delegation approval response RA, and the own node is switched to the master node and set. . The traveling ECU 6 (B) receives the delegation approval response RA and switches the own node to the slave node. The body-system ECU 6 (A), which is the master node after switching, updates the polling cycle by updating the polling cycle from the slave node (the traveling system ECU 6 (B) in FIG. 14) whose communication order is determined next to its own node. Start sending.

  On the other hand, when the master node is not switched, that is, when the body ECU 6 (A) does not approve the delegation of the master authority after receiving the delegation destination designation header HA, as shown in FIG. In the response following the delegation destination designation header HA, the system ECU 6 (A) describes the content not approving the master authority delegation (content of the error type identification code = “abnormal”) in the delegation approval field (Slave Error Field: FIG. 10). Then, it is transmitted as a delegation non-approval response RA ′ and the own node is set and maintained as a slave node. On the other hand, the traveling system ECU 6 (B) receives the delegation non-approval response RA ′ and maintains its own node as a master node while maintaining the slave node (seat ECU 2 (A) in FIG. 15) next to the delegation destination node. Send the specified header.

  In the above embodiment, as shown in FIG. 7, the LIN message frame can correspond to both the delegation-type transfer pattern and the request-type transfer pattern, so that a delegation field (Delegation_1 Field) and a delegation are included in the header. Both a request approval field (Master Error Field) and a response include both a delegation approval field (Slave Error Field) and a delegation request field (Delegation_2 Field). Whether or not to transfer the master authority is sufficient if it is possible to specify the description contents of the delegation field included in the header and the description contents of the delegation approval field included in the response in the delegation-type transfer pattern. It is sufficient that the description contents of the delegation request field included in the response and the description contents of the delegation request approval field included in the header can be specified (these fields are hereinafter referred to as “valid fields”). Therefore, the delegation request approval field and the delegation request field in the delegation-type transfer pattern, and the delegation field and the delegation approval field in the request-type transfer pattern, respectively, seem to be unnecessary at first glance. "). However, if it is determined whether a delegation-type transfer pattern or a request-type transfer pattern is being implemented, and redundant fields in each transfer pattern are deleted each time, what are the additional fields in the header or response? In order to identify whether the field is an additional field, complicated internal processing including determination of the transfer pattern type is required. Therefore, regardless of which transfer pattern is being implemented, the field configuration in the header or response is always constant, and additional fields that are redundant fields in each transfer pattern are not specifically deleted. Yes.

  According to the configuration of the in-vehicle communication network system 1 of the above embodiment, in the LIN cluster 50, the attribute switching that enables switching of a plurality of LIN nodes (gateway nodes) 6 (A) and 6 (B) between a master node and a slave node. This is configured as a possible type node, and any one of the attribute switchable type nodes is set as a master node of the LIN cluster 50, and the remaining one is set as a slave node of the LIN cluster 50 according to the scene (master). / Slave setting switching means). Since the authority of the master node can be transferred at any time between these attribute switchable type nodes 6 (A) and 6 (B), the LIN node 4 that is the master node can always be maintained at one at a certain moment. Not against the protocol. Therefore, even though a plurality of LIN nodes 6 (A) and 6 (B) that can serve as master nodes are provided for the same slave node group, the LIN communication bus 5 is single, and the physical layer is wasted. Redundancy can be prevented. Further, arbitration as to which of the attribute-switchable nodes (A) and 6 (B) becomes the master node may be performed via the LIN communication bus 5, so both nodes (A) and 6 (B). There is no need to provide a new communication line 107 as shown in FIG.

  The attribute-switchable nodes (gateway nodes) 6 (A) and 6 (B) communicate with each other in the LIN cluster 50 via the same LIN communication bus 5 regardless of whether the node is set as a master node or a slave node. To do. Therefore, as shown in FIG. 2, each LIN node (only 6 (A), 6 (B), 4 (A) is shown in FIG. 2) has one LIN transceiver corresponding to the LIN communication bus 5. It can be configured as having only. Thereby, the effect of preventing unnecessary redundancy of the LIN physical layer is further enhanced.

  Next, one LIN communication bus 5 constituting the LIN cluster 50 is distributedly connected to a plurality of gateway nodes 6 (A) and 6 (B) forming CAN nodes, and the gateway nodes 6 (A) and 6 (B ) As an attribute switchable type node so that master / slave switching is possible. Therefore, even if the attribute switchable type node (for example, body system ECU 6 (A)) that is the current master node goes down, Another living attribute switchable node (for example, traveling system ECU 6 (B)) can be switched to the master node. Thereby, the fail-safe function of the LIN cluster 50 is remarkably improved, and the reliability can be dramatically increased. Further, since the gateway nodes (attribute switchable nodes) 6 (A) and 6 (B) that can be master nodes are both CAN nodes, it is easy to ensure synchronization accuracy in the LIN cluster 50.

  In this case, the body system ECU 6 (A) is determined as a regular master node of the LIN cluster 50, and the travel system ECU 6 (B) is defined as at least a part of the functions of the regular master node, for example, the seat position, the handle position, the pedal position, or the seat. The function of automatically adjusting the belt position to the set value (when comfort is prioritized) may be determined as alternative master node candidates that can be taken over.

  As described with reference to FIG. 4, the body system ECU 6 (A) and the traveling system ECU 6 (B), which are attribute-switchable nodes, have user convenience and comfort according to the communication state being monitored by each node. The priority scene (that is, normal time) and the safety priority scene (that is, when a collision is detected) are determined and detected, and each scene suitable node, that is, the body ECU 6 (A) in the former, In the latter, since the traveling system ECU 6 (B) is switched to the master node as needed, fine control according to the scene is possible. Note that the body node ECU 6 (A) is set as the master node in the scene (communication state) where user convenience and comfort are prioritized, and the driving system ECU 6 (B) is set as the master node in the scene (communication state) where safety is prioritized. It is also clear that the priority order is set high, and the master node and the slave node are switched based on the priority order corresponding to each scene.

  Further, as shown in FIG. 1, a plurality of gateway nodes 6 (A) and 6 (B) to which the LIN communication bus 5 is distributed and connected are a plurality of CANs forming different control systems (that is, a body system and a traveling system). Clusters 100 (A) and 100 (B) are provided separately. By sharing one LIN cluster 50 between the CAN clusters 100 (A) and 100 (B) having different control purposes, the in-vehicle functions that the LIN cluster 50 plays (in FIG. 1, seat position, handle position, pedal position) Or, the seat belt position automatic adjustment function) can be applied to not only the comfort / convenience priority scenes of the body system, but also the safety priority scenes of the traveling system, and the LIN cluster 50 can be used more effectively. It is illustrated.

  Note that the in-vehicle communication network system 1 in FIG. 1 can be operated as follows. Specifically, this is a mode in which the attributes of the gateway nodes (attribute switchable nodes) 6 (A) and 6 (B) are switched according to the key switch position during parking. It is assumed that a well-known smart entry function is implemented in the vehicle. The fact that the vehicle is parked can be identified by the fact that the detection value of the vehicle speed sensor is 0 and the shift position sensor detects parking (P). As shown in FIG. 5, when the IG signal indicates the OFF state and the battery voltage + B is being received, the body system ECU 6 (A) is set as the master node, and the traveling system ECU 6 (B) stops operating ( That is, the power is turned off. In this state, the body system ECU 6 (A) detects, for example, the approach of a key (wireless portable device), detects and collates the key ID, and issues a control command for door lock locking / unlocking control.

  Next, as shown in FIG. 6, when the IG signal is ON and no occupant is detected in the passenger compartment, the traveling system ECU 6 (B) starts operating as a node, but is in a parking state. This is detected by the body system ECU 6 (A), and the body system ECU 6 (A) requests the traveling system ECU 6 (B) to set the slave node (that is, stop the master function). When the occupant can be identified from the key ID, the seat position, the handle position, the pedal position, or the seat belt position, which the occupant has set and registered in advance in consideration of ease of driving and boarding, is set to an appropriate position. Adjust automatically.

  In this state, when the vehicle speed increases to a certain level or more and shifts to the driving detection state, the adjustment of each position giving priority to comfort has already been completed, so the driving system ECU 6 (B) is requested to delegate master authority. Thus, the traveling system ECU 6 (B) is switched to the master node of the LIN cluster 50 related to the position adjustment mechanism. The traveling system ECU 6 (B) controls each position necessary for absorbing the impact at the time of a collision (or sudden acceleration, rapid deceleration, etc.) with each position set by the body ECU 6 (A) as a basic position. Do.

  Next, FIG. 16 shows an application example of the present invention to another control system. In this example, the body ECU 6 (A) and the A / C (air conditioner) ECU 6 (B) are attribute-switchable type nodes (each is a gateway node provided on a CAN cluster not shown). Further, the remaining slave nodes 4 (A) to 4 (D) of the LIN cluster 50 are respectively connected to P / W (power window) ECUs 104 (A) to 104 (D) (“D”, “P”, “RR”, “RL”). "Represents" driver's seat "," passenger seat "," rear right seat ", and" rear left seat ").

  The above configuration is intended to control the power window in association with the air conditioner in order to operate the air conditioner more efficiently. As shown in the upper part of FIG. 16, the body system ECU 6 (A) determines whether the vehicle is in the parking state by referring to the door lock, the state of the IG signal, the detection state of the shift position sensor, and the like, and the A / C ECU 6 ( Information relating to the determination result is transmitted to B). At this time, the body system ECU 6 (A) is set as a master node, and the A / CECU 6 (B) is set as a slave node.

  When the air conditioner control by the A / CECU 6 (B) is started in this state, when the scene determination information of the body system ECU 6 (A), for example, the freezing sensor provided in the window detects the frozen state, the body system ECU 6 ( A master authority transfer application is made from A) to A / CECU 6 (B), and the master node is switched to A / CECU 6 (B). FIG. 17 shows a polling sequence including node attribute switching in this case, but since the basic flow is exactly the same as FIG. 14, detailed description is omitted (FIG. 19 shows A / CECU 6 (B)). Shows the polling sequence when refusing the delegation offer: the basic flow is exactly the same as in FIG. 15). When the power window is controlled by the A / CECU 6 (B) as a master node, even if the power window switch is manually operated by the user, for example, a specific seat (for example, other than the driver's seat) until the frozen state is eliminated. A mode in which the power window operation of all seats) is prohibited can be exemplified. On the other hand, when the frozen state is eliminated and the cooperation with the air conditioner control becomes unnecessary, a request for delegating master authority is made from the body system ECU 6 (A) to the A / CECU 6 (B), and the master node is assigned to the day system ECU 6 (A ). FIG. 18 shows a polling sequence including node attribute switching in this case, but since the basic flow is exactly the same as FIG. 12, detailed description thereof is omitted.

  In addition to the time of freezing, for example, when the air conditioner is operated in a parking state under a hot sun, a control mode can be exemplified in which the power window is operated in the opening direction to accelerate the release of hot air inside the vehicle interior. In this case, when the vehicle interior temperature rises abnormally, the master node is switched from the body system ECU 6 (A) to the A / CECU 6 (B). At this time, the A / CECU 6 (B) performs control to automatically open the power window of a specific seat (for example, all seats) even if the power window switch is not manually operated by the user. When the vehicle interior temperature falls below a certain level and the cooperation control is no longer necessary, the body system ECU 6 (A) is returned to the master node.

  Next, in FIG. 20, in the LIN cluster 50 forming the power window control system, the body ECU 6 (A) is a regular master node of the LIN cluster 50, and the management ECU 6 (on the same CAN cluster as the body ECU 6 (A)) B) (normally a slave node) is defined as an alternative master node candidate capable of taking over at least a part of the functions of the regular master node. The management ECU 6 (B) monitors the operating state of the body system ECU 6 (A), which is a regular master node, based on communication information acquired by each CAN cluster 100 via the CAN communication bus 3. If an abnormality of a predetermined content is detected in the operating state of the body ECU 6 (A) (regular master node) being monitored, the management ECU 6 (B) that constitutes an alternative master node candidate is set as the master node. Switch. Thereby, even if the regular master node of the LIN cluster 50 goes down, the takeover by the alternative master node can be performed quickly, and the fail-safe function can be remarkably improved.

  In this case, the management ECU 6 (B) attempts to communicate with the body ECU 6 (A) by, for example, CAN communication, and switches to the master node of the LIN cluster 50 when communication becomes impossible. At this time, the body system ECU 6 (A), which is a regular master node, has a high possibility that the master authority transfer sequence via the LIN frame is not executable. The body ECU 6 (A) is disconnected from the LIN communication bus 5 and the management ECU 6 (B) is switched to the master node.

  In the embodiment described above, the number of attribute switchable nodes included in one LIN cluster is two. However, this may be three or more. In this case, one of the three or more attribute-switchable nodes is set as a master node, and the remaining one is set as a slave node or separated from the LIN cluster. Further, the attribute switchable node is not necessarily a CAN node (that is, a gateway node). For example, the concept of the present invention can be applied to a LIN cluster independent of a CAN cluster. Alternatively, only some of the plurality of attribute-switchable nodes may be configured as gateway nodes, and the remaining nodes may be configured as LIN nodes that do not configure gateway nodes.

The schematic block diagram which shows the 1st structural example of the vehicle-mounted communication network system of this invention. The figure which shows the principal part of the vehicle-mounted communication network system of FIG. 1 with the internal block of each node. The block diagram which shows an example of the software module structure of a gateway node. FIG. 3 is a first operation explanatory diagram of the in-vehicle communication network system of FIG. 1. The 2nd operation explanatory view of the in-vehicle communication network system of Drawing 1. FIG. 4 is a third operation explanatory diagram of the in-vehicle communication network system of FIG. 1. FIG. 2 is an explanatory diagram showing a LIN frame structure used in the in-vehicle communication network system of FIG. 1 in comparison with a conventional LIN frame structure. Explanatory drawing which shows the structural example of a delegation field. Explanatory drawing which shows the structural example of a delegation request | requirement approval field. Explanatory drawing which shows the structural example of a transfer approval field. Explanatory drawing which shows the structural example of a delegation request | requirement field. The figure which shows the polling sequence in the request type | mold transfer pattern in the vehicle-mounted communication network system of FIG. 1 (at the time of normal). The figure which shows the polling sequence in the request type | mold transfer pattern in the vehicle-mounted communication network system of FIG. 1 (at the time of abnormality). The figure which shows the polling sequence in the same delegation type transfer pattern (at the time of normal). The figure which similarly shows the polling sequence in a delegation type transfer pattern (at the time of abnormality). The schematic block diagram which shows the 2nd structural example of the vehicle-mounted communication network system of this invention. The figure which shows the polling sequence in the transfer type transfer pattern in the vehicle-mounted communication network system of FIG. 16 (at the time of normal). The figure which similarly shows the polling sequence by a request type | mold transfer pattern (at the time of normal). The figure which similarly shows the polling sequence in a delegation type transfer pattern (at the time of abnormality). The schematic block diagram which shows the 3rd structural example of the vehicle-mounted communication network system of this invention. The 1st block diagram which shows the structure of the conventional vehicle-mounted communication network system. The 2nd block diagram which shows the structure of the conventional vehicle-mounted communication network system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 In-vehicle communication network system 2 CAN node 3 CAN communication bus 5 LIN communication bus 4 LIN node (slave node)
6 Gateway node (attribute switching type node)
HA Delegation destination designation header RA Delegation approval response RB Delegation destination designation response

Claims (14)

An in-vehicle communication network system including a LIN cluster in which a plurality of LIN nodes are connected by a single LIN communication bus,
Two or more of the LIN nodes forming the LIN cluster are attribute-switchable nodes that can be switched between a master node and a slave node, and any one of these attribute-switchable nodes is designated as the LIN cluster. Master / slave setting switching means is provided in the master node, so that the remaining ones can be switched to the slave nodes of the LIN cluster, respectively .
The message frame structure for data transmission in LIN communication consists of a header transmitted as a master task and a response transmitted as a slave task, and communication messages are exchanged by alternately repeating header transmission / reception and response transmission / reception. And
The attribute-switchable node includes a header sending means for sending the header to the LIN communication bus when operating as the master node, a response receiving means for receiving the response, and a slave node. The vehicle-mounted communication network system further comprises: a header receiving unit that receives the header; and a response sending unit that sends the response to the communication bus . The attribute switchable node includes
When the switching condition is satisfied in the state set in the master node, the other attribute-switchable type nodes set in the slave node are designated in advance in association with the switching condition. A master authority delegation notification means for performing a master authority delegation notification for applying for a master authority delegation to the existing person via the LIN communication bus;
When the master authority transfer offer notification is received in the state set in the slave node, it is determined whether or not to accept the master authority, the determination result is returned, and the determination to accept the authority is performed. A master switching control means for switching the node setting of the own node from the slave node to the master node,
Slave switching for switching the node setting of the master node from the master node to the slave node when the determination result is received in the state set in the master node and the determination result is positive with respect to the authority acceptance Control means;
The in-vehicle communication network system according to claim 1, comprising: The header includes a break field indicating the start of a message, a synchronization field incorporating a time correction reference waveform, an identifier field for specifying a slave node as a communication destination, and an attribute switchable node as the master node. And a delegation field for specifying whether to perform the master authority delegation,
On the other hand, in the response, as specified as the communication destination by the identifier field of the header, a data field incorporating data to be transmitted, an error check field, and an attribute switchable type serving as the slave node node, wherein the vehicle communication network system according to claim 1, wherein the delegation authorization field specifying whether or not to approve the master authority delegation is incorporated indicated by the delegation field of the header. A communication order for prescribing a predetermined polling cycle is uniquely given to the plurality of LIN nodes including the attribute switchable node,
When each of the attribute switchable nodes is set as the master node, the header transmission unit and the response reception unit transmit the header on the LIN communication bus to the corresponding slave node. It is performed repeatedly while changing the slave node as a communication destination sequentially according to the polling cycle while alternating with the reception of the response from
The master node that is the delegation source of the master authority is the delegation source node, the slave node that is the delegation destination of the master authority is the delegation destination node,
As the communication order of the delegation destination node arrives in the polling cycle, the delegation source node has a delegation destination designation header including a description describing the delegation field as a master authority delegation destination in the delegation field Send out as
The delegation destination node receives the delegation destination designation header, determines whether to approve the delegation of the master authority, and if so, sends a response following the delegation destination designation header in the delegation approval field to the master The header is transmitted in the form of transmitting as a delegation approval response describing the contents for authorizing the authority delegation and switching the own node to the master node and updating the polling cycle from the slave node whose communication order is determined next to the own node. While starting to send
4. The in-vehicle communication network system according to claim 3, wherein the delegation source node receives the delegation approval response and switches and sets its own node to a slave node. After the delegation destination node receives the delegation destination designation header, if the master authority delegation is not approved, a response following the delegation destination designation header is described, and the delegation approval field describes the content that does not approve the master authority delegation And send it as a delegation non-approval response and maintain the own node as a slave node,
The delegation source node receives the delegation non-approval response and maintains its own node as a master node, and continues the polling cycle by sending a header designating the slave node of the next rank of the delegation destination node. The in-vehicle communication network system according to claim 4 . The attribute switchable node includes
When the switching condition is satisfied in the state set in the slave node, a master authority delegation request notification for requesting master authority delegation is sent to the other attribute switchable node set in the master node. Master delegation request notifying means for performing via the LIN communication bus;
When the master delegation request notification is received in the state set in the master node, it is determined whether or not to accept the delegation of the requested master authority, and the determination result is returned and the delegation is accepted. Slave switching control means for switching its own node setting from the master node to the slave node,
When the determination result is received in a state where the slave node is set, and the determination result is positive with respect to the delegation of the master authority, the node setting is switched from the slave node to the master node. Master switching control means;
The in-vehicle communication network system according to any one of claims 2 to 5 , comprising: Comprising the requirements of claim 3 ;
The response incorporates a delegation request field that specifies whether or not to request the master authority delegation to the attribute switchable node that is the master node,
The in-vehicle communication network system according to claim 6 , wherein the header incorporates a delegation request approval field for specifying whether or not the attribute switchable node serving as the slave node approves the master authority delegation request. . A communication order for prescribing a predetermined polling cycle is uniquely given to the plurality of LIN nodes including the attribute switchable node,
When each of the attribute switchable nodes is set as the master node, the header transmission unit and the response reception unit transmit the header on the LIN communication bus to the corresponding slave node. It is performed repeatedly while changing the slave node as a communication destination sequentially according to the polling cycle while alternating with the reception of the response from
The delegation destination node sends out a response describing a request that designates the delegation destination node as a master authority delegation destination in the delegation request field as a delegation destination designation response,
The delegation source node receives the delegation destination designation response, determines whether to approve the delegation of the master authority, and if so, receives the delegation destination designation response from the delegation destination node. At the stage, the header following the delegation destination designation response is described, the contents for approving the master authority delegation request are described in the delegation request approval field, and the delegation destination node is set as the master authority delegation destination in the delegation field Sending out the polling cycle from the delegation destination node as a delegation destination designation header with the header describing the contents to be specified,
The delegation destination node receives the delegation destination designation header, determines whether to approve the delegation of the master authority, and if so, sends a response following the delegation destination designation header in the delegation approval field to the master Sending as a delegation approval response describing the contents of approval of authority delegation, switching the own node to the master node, and taking over the polling cycle from the slave node whose communication order is determined next to the own node While starting a new transmission,
8. The in-vehicle communication network system according to claim 7, wherein the delegation source node receives the delegation approval response and switches and sets its own node to a slave node. When the delegation source node receives the delegation destination designation response and rejects the master authority delegation request, the master authority delegation request is rejected in the delegation request approval field with a header following the delegation destination designation response. The delegation request rejection header describing the contents to be transmitted, the own node is set and maintained in the master node, and the polling cycle is continued by sending a header designating the next-ranked slave node of the delegation destination node. Item 9. The in-vehicle communication network system according to Item 8 . A CAN cluster in which a plurality of CAN nodes are connected by a CAN communication bus, and a plurality of the LIN nodes are connected by a single LIN communication bus, and the LIN cluster is connected to the CAN cluster by using the CAN node as a gateway node It is configured as a composite in-vehicle communication network system consisting of
A plurality of the CAN node and said gateway node, wherein with one of the LIN communication bus constituting the LIN cluster is dispensed connected to the plurality of gateway nodes, are configured each gateway node as the attribute switchable type node The in-vehicle communication network system according to any one of claims 1 to 9 . The master / slave setting switching unit includes a communication state monitoring unit that monitors a communication state of the CAN cluster or the LIN cluster, and when a predetermined switching condition is satisfied in the communication state being monitored, The in-vehicle communication network system according to claim 10, wherein setting switching of the master node and the slave node in the attribute switchable node is performed. For each predetermined type of the communication state, a priority order for setting a plurality of the attribute switchable type nodes as the master node is determined, and the master / slave setting switching means is set to the established communication state. The in-vehicle communication network system according to claim 11 , wherein setting switching of the master node and the slave node is performed based on the corresponding priority order. The plurality of gateway nodes to which the LIN communication bus is distributed and connected are provided to be distributed to a plurality of CAN clusters forming different control systems,
The communication status monitoring means monitors the control status of the control system corresponding to each CAN cluster based on communication information acquired via the CAN communication bus, and the master / slave setting switching means when the control state in is satisfied a predetermined switching condition, claim 11 or claim a gateway node belonging to the pre-designated cAN clusters in a manner that associates with the control state is to set the master node 12. The in-vehicle communication network system according to 12 . One of the plurality of gateway nodes to which the LIN communication bus is distributed and connected is defined as a regular master node of the LIN cluster, while a slave node constituting the remaining gateway node is at least a part of the function of the regular master node As an alternative master node candidate that can take over,
The communication state monitoring means monitors the operating state of the regular master node based on communication information acquired by each CAN cluster via the CAN communication bus, and the master / slave setting switching means is under monitoring. The in-vehicle communication according to claim 13 , wherein when an abnormality having a predetermined content is detected in an operation state of the regular master node, a slave node that is a candidate for the alternative master node is switched to the master node. Network system.

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