JP2007318199A - Relay connection unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relay connection unit with excellent reliability, which carries out relaying of a message at a high speed to the utmost extent and decreasing the relaying of wasteful messages as less as possible. <P>SOLUTION: The relay connection unit includes: a plurality of ports each comprising an in-vehicle LAN communication means respectively connected to a plurality of communication lines and transmitting/receiving messages; a buffer for sequentially storing the messages received via the ports in the unit of a bit; a relay information recording medium for recording a relationship between identification information of the message required to be relayed and relay destination ports; and a relay processing means that discriminates a relay destination port corresponding to identification information of the received message by comparing the identification information with the identification information recorded in the relay information recording medium at the point of time when the identification information of the received message is received, and relay-transmits the message sequentially stored in the buffer from a relay start point of time by determining the relay start point of time for starting relay transmission of the messages in the buffer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an in-vehicle relay connection unit, and more particularly to a relay connection unit capable of relaying messages transmitted and received using a plurality of communication lines at high speed and improving reliability.

  In recent years, a large number of electronic control units (ECUs) are mounted on automobiles, and the number thereof tends to increase. Each ECU is configured to be connected to each other via a communication line so that an in-vehicle LAN is constructed and messages can be transmitted and received between the ECUs. Furthermore, in order to reduce the amount of messages transmitted / received via each communication line, an ECU that connects a plurality of communication lines by a relay connection unit and is connected to one communication line (a single segment of the in-vehicle LAN) It has been done to reduce the number of.

  FIG. 14 is a diagram schematically showing a configuration of a conventional general relay connection unit 90 shown in “Introduction to CAN” of Non-Patent Document 1. That is, the relay connection unit 90 includes ports 92A and 92B made of in-vehicle LAN communication means connected to communication lines 91A and 91B made of wire harnesses, and a CPU (arithmetic processing unit) 93 connected to the ports 92A and 92B. And a memory 94 for recording relay information indicating the relationship between at least the identification information of the message to be relayed and the relay destination port.

  After receiving all the messages received via the ports 92A and 92B, the CPU 93 sequentially compares the identification information attached to the messages with the identification information included in the relay information recorded in the memory 94, and determines other ports. It is determined whether the message is to be relayed to 92B and 92A. If the CPU 93 determines that the message should be relayed, the message is relayed to the ports 92B and 92A.

Introduction to CAN Published: October 1, 2003 Publisher: Renesas Technology Internet (URL: http://www.renesas.com/jpn/products/mpumcu/specific/can_lin_mcu/candoc/rjj99z0001_entry_0400.pdf)

  However, like the relay connection unit 90 shown in Non-Patent Document 1, when the CPU 93 executes the series of processes related to message relay by software, there is a problem that the CPU 93 is required to have high processing capability. That is, there is a problem that the time until the message arrives at the receiving node is delayed as the amount of messages for determining whether it is necessary to perform relaying handled by the CPU 93 increases. In particular, since in-vehicle LANs tend to become more complex in recent years, a relay connection unit that relays three or more communication lines has become necessary, and the number of messages taken into the CPU 93 increases. Since this is unavoidable, there is a problem that the delay time for relaying becomes longer.

  Among the messages received by the relay connection unit 90, there is a message that contains an error due to a malfunction of the transmission source ECU. Moreover, it is possible that the thing which is not accurate by the influence of the noise mixed on communication line 91A, 91B etc. is also contained. In the conventional relay connection unit 90, when a message including an error is relayed, there may be a problem that the communication load in the relay destination communication line is unnecessarily increased.

  The present invention has been made in consideration of the above-mentioned problems, and is capable of relaying messages as fast as possible, and having excellent reliability that can reduce unnecessary message relays as much as possible. To provide a connection unit.

In order to solve the above problems, the present invention provides:
A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparison with the identification information recorded in the relay information recording means, and the message in the buffer for each relay destination port The relay start time for starting the relay transmission of the message is determined, and the message in the buffer is relayed and transmitted to a certain relay destination port after receiving the message and confirming the accuracy of the message. There is provided a relay connection unit comprising relay processing means for relaying and transmitting messages stored one by one in the buffer from the time when a relay destination port of a message being received can be determined.

  With the above-described configuration, the relay processing unit determines a relay start time for starting relay transmission of the message in the buffer for each relay destination port. Accordingly, the relay processing means completes reception of the message at a certain relay destination port and confirms the accuracy of the message, and then relays and transmits the message in the buffer, and the relay destination of the message being received is transmitted to another relay destination port. Messages stored one by one in the buffer can be relayed and transmitted from the time when the port can be identified.

  That is, it is possible to adjust the relay start time of the message to be relayed according to the communication status on the communication line connected to each relay destination port. In other words, when relaying to a communication line that is preferably relayed at high speed, the message reception from the relay source port and the message transmission to the relay destination port are processed in parallel, as much as possible. While high-speed message relay processing can be performed, when relaying to a communication line where an increase in the communication load factor is not desirable, confirm that the message received from the relay source port is accurate and then error Only messages without a message can be relayed to the relay destination port.

  The port transmits and receives messages that comply with various in-vehicle LAN standards such as CAN, Flex-Ray, and LIN, and the buffer is a memory configured to read and write messages to be transmitted and received in bit units. A collection of bit storage elements such as flip-flops is preferred. Similarly, it is preferable that the relay information recording means is a memory configured to be readable at a high speed, and has a bus capable of accessing at high speed a part storing the identification information in the buffer. Further, the relay processing means is preferably a logic circuit configured to be able to access the buffer and the relay information recording means at high speed, and a comparator for comparing the identification information in the buffer and the identification information recorded in the relay information recording means It is preferable to have such a logic circuit. The relay start time includes at least the time when the identification information is received and the relay destination port can be confirmed, and the time when the message is received to the end and the accuracy is confirmed.

Communication load factor monitoring means for monitoring the communication load factor in the communication line connected to each port,
Preferably, the relay processing means relays the message after confirming the accuracy of the message when a port connected to a communication line having a high communication load factor is used as a relay destination port.

  With the above configuration, it is possible to monitor the communication load factor in each communication line, and relay the message after confirming the accuracy of the message when a port connected to a communication line with a high communication load factor is used as a relay destination port. Is possible. As a result, a message that has been abnormally received due to an abnormality in the transmission source or an abnormality in the communication line can be deleted in the relay connection unit, and unnecessary increase in the communication load factor can be prevented by relaying unnecessary messages. In addition, since the relay connection unit does not need to set the relay start time for each port from the beginning, the information to be set in the relay connection unit is reduced, and the environment of the in-vehicle LAN in which the relay connection unit is arranged is flexible. Can be adapted to.

Furthermore, the present invention provides
A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparison with the identification information recorded in the relay information recording means, and relay transmission is started for each identification information The relay start time is determined, and the message in the buffer is relayed and transmitted after confirming the correctness of the message for the message of certain identification information, while the message of another identification information is being received. There is provided a relay connection unit comprising relay processing means for relaying and transmitting a message in the buffer from the time when a message relay destination port can be determined.

  With the above-described configuration, the relay processing means defines a relay start time for starting relay transmission of the message in the buffer for each message identification information. Therefore, the relay processing means completes reception of the message for a certain identification information and confirms the accuracy of the message, and then relays and transmits the message in the buffer, while the message being received for another identification information message. It is possible to relay and transmit the messages stored in the buffer one by one from the time when the relay destination port can be determined.

  That is, it is possible to adjust the relay start time of the message to be relayed according to the request such as the importance level and the worst delay time of each message. In other words, for messages that are preferably relayed at a higher speed, the message reception process from the relay source port and the message transmission to the relay destination port are processed in parallel, thereby enabling the message relay process as fast as possible. On the other hand, for messages where reliability of the message is more important than shortening the delay time, after confirming that the message received from the relay source port is accurate, only the error-free message is relayed. Can be relayed to the port. The relay start time includes at least the time when the identification information is received and the relay destination port can be confirmed, and the time when the message is received to the end and the accuracy is confirmed.

  The port transmits and receives messages that comply with various in-vehicle LAN standards such as CAN, Flex-Ray, and LIN, and the buffer is a memory configured to read and write messages to be transmitted and received in bit units. A collection of bit storage elements such as flip-flops is preferred. Similarly, it is preferable that the relay information recording means is a memory configured to be readable at a high speed, and has a bus capable of accessing at high speed a part storing the identification information in the buffer. Further, the relay processing means is preferably a logic circuit configured to be able to access the buffer and the relay information recording means at high speed, and a comparator for comparing the identification information in the buffer and the identification information recorded in the relay information recording means It is preferable to have such a logic circuit.

  After the message is received, the accuracy of the message is confirmed to monitor the relationship between the identification information of the message and the error rate, and after confirming that the message having the identification information with a high error rate has been received correctly It is preferable to include an error rate monitoring unit that can dynamically adjust the relay start time so as to relay the message.

  With the above configuration, for a message having identification information with a high error rate, after confirming that this message has been received correctly, the relay start time can be dynamically adjusted so that the message is relayed. Therefore, when receiving a message originating from an ECU that frequently sends an error message, confirm the accuracy of this message and relay it to the relay destination port to relay unnecessary messages. This can prevent the wasteful increase of the communication load factor. In addition, since the relay connection unit does not need to set the relay start time for each piece of identification information from the beginning, the information to be set in the relay connection unit is reduced, and the in-vehicle LAN environment in which the relay connection unit is arranged is reduced. It can be flexibly adapted.

Furthermore, the present invention provides
A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparing with the identification information recorded in the relay information recording means, and the relay source port and the relay destination of the message Provided is a relay connection unit comprising relay processing means for determining a relay start time for starting relay transmission in accordance with a ratio of port communication speeds and relaying the message in the buffer to a relay destination port. ing.

  With the above configuration, messages being received via each port can be stored in the buffer one by one. Further, the relay processing means can determine the relay destination port of the message using the identification information already stored in the buffer even when the message is being received, and relay the message in the buffer to the relay destination port. Send it. Therefore, the relay processing means can perform in parallel the process of receiving messages from the relay source port and storing them one by one in the buffer, and the process of relaying and transmitting the messages in the buffer to the relay destination port.

  Further, the relay processing means determines a relay start time at which relay transmission is started in accordance with the ratio of the communication speeds of the message relay source port and the relay destination port. Here, the relay start time includes at least the time when the identification information is received and the relay destination port can be confirmed, and the time when the message is received to the end. When the communication speed of the relay destination port is faster than the communication speed of the relay source port, the time when the message is received to the end is set as the relay start time, and the communication speed of the relay destination port is less than the communication speed of the relay source port. In some cases, it is preferable that the relay start time is the time when the identification information is received and the relay destination port is confirmed.

  Furthermore, as the relay start time point, it is possible to select a time point when the reception completion bit number of the message received from the relay source port becomes a predetermined number (a bit number with a constant ratio of the reception completion message length to the message length). preferable. That is, when the relay processing means transmits a message being received from the relay source port to the relay destination port by determining the relay start time at which relay transmission is started according to the ratio of the communication speed of the relay source port and the relay destination port. It is possible to prevent the bit information stored in the buffer from being exhausted.

  The port transmits and receives messages that comply with various in-vehicle LAN standards such as CAN, Flex-Ray, and LIN, and the buffer is a memory configured to read and write messages to be transmitted and received in bit units. A collection of bit storage elements such as flip-flops is preferred. Similarly, it is preferable that the relay information recording means is a memory configured to be readable at a high speed, and has a bus capable of accessing at high speed a part storing the identification information in the buffer. Further, the relay processing means is preferably a logic circuit configured to be able to access the buffer and the relay information recording means at high speed, and a comparator for comparing the identification information in the buffer and the identification information recorded in the relay information recording means It is preferable to have such a logic circuit.

  The relay start time is a time when the relay destination port can be identified by receiving the identification information when the communication speed of the relay destination port is equal to or lower than the communication speed of the relay source port. When the communication speed is higher than the communication speed of the relay source port, the time when the message transmission completion time to the relay destination port is adjusted to be later than the time when the message reception from the relay source port is completed It is preferable that

  That is, when the communication speed of the relay destination port is faster than the communication speed of the relay source port, the message transmission completion time to the relay destination port is later than the message reception completion time from the relay source port. By setting the time adjusted so as to be the relay start time, it is possible to reliably prevent the bit information stored in the buffer from being exhausted when a message being received from the relay source port is transmitted to the relay destination port.

Furthermore, in the present invention,
Buffer management means for managing the storage area in the buffer divided into a plurality of slot areas;
Transmission management means for relaying and transmitting a message corresponding to the transmittable port using a buffer management means when each port is in a transmittable state,
The buffer management means includes
When a message to be stored in the buffer is received from each port, the slot area in which an empty space is generated is searched, information indicating that the slot area is in use is stored, and then the slot area is stored. While storing the message being received one by one, and storing the relay destination port and the relay start time of the message determined by the relay processing means when the identification information of the message has been stored,
When receiving a request for relay transmission of a message from the transmission management means, a slot area for storing a message to be output to a relay destination port that is in a transmittable state by sequentially tracing each slot area in use After searching and relaying the message stored in the slot area to the relay destination port, the relay destination port information in the slot area is deleted, and
It is preferable that when there is no relay destination port stored in the slot area, it is stored that the slot area is an empty slot and the slot area is released.

  With the above configuration, when a message is input via a port, the buffer management means secures an empty slot area in the buffer, and the message is stored in this empty slot area. When the identification information is received, the relay processing means compares the identification information with the identification information stored in the relay information recording means, and the relay destination port and the relay start time are determined. The relay start time is stored in the slot area. When the relay destination port is not set, reception of this message is interrupted, and the buffer management means stores that the slot area is an empty slot and releases the slot area.

  Next, when the port is in a transmittable state, a message corresponding to the transmittable port is selected using the output destination information stored in the slot area, and output to the port. That is, it is possible to relay a message being received when the identification information is received.

  The information indicating that the slot area is in use or free is stored in each slot area in use by sequentially storing information indicating the position of the next slot area, thereby sequentially linking the slot areas in use. It is preferable that the information be linked to the chain structure and managed. As a result, a large number of slot areas shared by each port can be integrated and managed. It is also possible to check the usage status of each slot area using flag information.

  The relay connection unit of the present invention does not involve a CPU that is operated by software such as an operation program as in the prior art, and uses a port, buffer, and relay information recording means that can be realized by simple hardware for relaying messages. It is possible to execute processing. Therefore, in comparison with the conventional case where processing is performed mainly by a CPU that operates by software, the relay processing means that executes processing by hardware performs input / output processing of bit information by each electronic circuit distributed for each port. Can be pipelined in parallel, there is almost no processing delay due to an increase in the number of ports. In addition, since processing delay due to an increase in messages is less likely to occur than in the past, it is possible to cope with an increase in nodes due to multifunctionalization of automobiles.

  If the relay start time for starting relay transmission of the message in the buffer can be adjusted by the identification information of the relay destination port and / or relay target message, the error message is deleted by the relay connection unit and each communication is performed. It is possible to prevent an increase in the communication load factor on the line, and to relay and transmit a message as quickly as possible. That is, both improvement in reliability and reduction in relay delay can be achieved.

  In addition, when the relay start time for starting relay transmission can be adjusted according to the communication speed ratio between the relay source port and the relay destination port, when a message being received from the relay source port is relayed to the relay destination port. Therefore, it is possible to reliably prevent the bit information stored in the buffer from being exhausted, so that it is possible to relay a message as fast as possible between communication lines having a speed difference while improving reliability.

Hereinafter, embodiments of the relay connection unit 1 of the present invention will be described with reference to the drawings.
1 to 7 are diagrams for explaining a first embodiment of the present invention. FIG. 1 shows a relay connection unit 1 according to the first embodiment (hereinafter, the relay connection unit 1 of the first embodiment is denoted by reference numeral 1a). 2 is a block diagram conceptually showing the interior of the relay connection unit 1a, FIG. 3 is a block diagram showing the internal configuration of the relay connection unit 1a, and FIG. 4 is a slot in the buffer. FIG. 5 is a diagram illustrating an example of a region management method, FIG. 5 is a diagram illustrating an example of relay information, and FIGS. 6 and 7 are diagrams illustrating an example of relay using the relay connection unit 1a.

  In FIG. 1, 2 is an ECU connected to the relay connection unit 1a (hereinafter, reference numerals 2A, 2B,... Are used to distinguish between the ECUs 2), and 3 is a communication for connecting each ECU 2 to the relay connection unit 1a. Lines (hereinafter, reference numerals 3A, 3B... Are used when the communication lines 3 are described separately).

  The ECU 2 ... has an input / output means 2a for messages ma, mb ... compliant with the CAN standard, for example, the communication line 3 is a twisted pair cable compliant with the CAN standard, and the communication lines 3A, 3B are 500 kps, The communication line 3C transmits and receives messages at a communication speed of 1 Mbps, and the communication line 3D at 250 kbps. Each of the communication lines 3A, 3B,... May constitute an in-vehicle LAN that conforms to various standards such as LIN, CAN, FlexRay (registered trademark), MOST, D2B, IDB1394, Ethernet (registered trademark), and the like. Good. Moreover, the vehicle-mounted LAN based on a different standard for every communication line 3 may be comprised.

  Each communication line 3A, 3B, 3C, 3D is connected to a group of ECUs 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, respectively, and each of the segments Sa, Sb, Sc, Sd (hereinafter, these are simply referred to as segments Sa to Sd), and the relay connection unit 1a relays the message m (that is, any one of the messages ma, mb...) Between the plurality of segments Sa to Sd. Thus, the in-vehicle LAN network 4 configured to be able to communicate with each other is formed. Needless to say, a single ECU 2 may be connected to each of the segments Sa to Sd to perform more reliable communication.

  As shown in FIG. 2, the relay connection unit 1a according to the present embodiment is connected to a plurality of communication lines 3A to 3D and transmits and receives a message m (hereinafter referred to as ports 10a to 10d). A port 10), a relay processing unit 11 connected to these ports 10 a to 10 d for relaying the message m, a CPU 12 for controlling the relay processing unit 11 to manage the relay processing, and an operation of the CPU 12 And a recording unit 13 in which setting values of the program and the relay processing unit 11 are recorded. In the present embodiment, the configuration of the relay connection unit 1a is described assuming that the number of the ports 10 is 4, but it goes without saying that the number of the ports 10 is not limited to the present invention.

  The ports 10a to 10d are in-vehicle LAN communication means that enable transmission and reception of the message m according to the in-vehicle LAN communication protocol in each segment Sa to Sd formed using the communication lines 3A to 3D, respectively. Are configured to be operable. However, the ports 10a to 10d may be physically provided in one in-vehicle LAN communication means.

  The relay processing unit 11 includes a memory-embedded logic IC such as an FPGA (Field Programmable Gate Array) in which a logic circuit for relaying the message m is recorded, and a plurality of functional blocks formed by writing necessary information ( IP (Intellectual Property), and relays a plurality of messages m in parallel. Also, the functional block constituting the relay processing unit 11 relays to the relay destination port being received after the relay connection unit 1a has received the message m being received up to its identification information and the relay destination port can be determined. Select freely the cut-and-through relay that starts transmission and the store-and-forward relay that relays the message m that has been received after the relay connection unit 1a has received the message m to the relay destination port. It is configured to be able to do.

  In the present embodiment, the relay processing unit 11 is formed by using FPGA to enhance its versatility. However, the relay processing unit 11 uses a custom IC such as an application specific integrated circuit (ASIC). The functional block may be fixedly formed. Further, the port 10, the relay processing unit 11, the CPU 12, and the ROM 13 may be formed in one IC. The detailed configuration of the functional block will be described later.

  For example, the CPU 12 writes data for forming the functional block in the memory-embedded logic IC when the relay connection unit 1a is started (or reset), so that the memory-embedded logic IC is appropriately relayed by hardware. It functions as the relay processing unit 11 that performs processing. Further, the communication status by the port 10 is monitored and relaying by the relay processing unit 11 is managed. Further, the CPU 12 may partially relay the message m in conjunction with the relay processing unit 11.

  The recording means 13 is a non-volatile ROM. The ROM 13 is a functional block written in a hardware description language or the like that is read by the CPU 12 at the time of startup or the like and written into the relay processing unit 11. Is recorded as a setting value of the relay processing unit 11. The ROM 13 stores a management program for causing the CPU 12 to manage the communication status of the port 10 and the relay processing unit 11. However, if the formation of the functional block is fixed at the time of manufacture and the functional block is not formed when the relay connection unit 1a is activated in the memory-embedded logic IC, the ROM 13 uses the memory-embedded logic IC as the relay processing unit 11. There is no need to have data to make it work.

  Therefore, in the relay connection unit 1a configured as described above, the CPU 12 determines the relay start time of the message m for each of the ports 10a to 10d, as indicated by arrows Va to Vd, and the ports 10a to 10d. The message m can be relayed from an appropriate relay processing start time according to the communication status. In the initial state in the present embodiment, for relay processing using the ports 10a, 10b, and 10d as relay destination ports, the relay processing start time is set so that priority is given to increasing the relay speed by the cut-and-through relay. With regard to the relay processing in which the port 10c is set as a relay destination port, the relay processing start time is set so that priority is given to performing reliable relay over the relay speed by the store-and-forward relay.

  Next, the configuration of the relay connection unit 1a of the present embodiment will be described in more detail with reference to FIG. The functional blocks formed in the relay processing unit 11 are roughly divided into a buffer 20 for storing the messages m received via the port 10 one by one in units of bits, and a storage area in the buffer 20 is divided into a plurality of slot areas SL. A buffer management means 21 that manages the information separately, a relay information recording means 22 that records the relationship between the identification information of the message m that needs to be relayed and the relay destination port, and the relay of the message m stored in the buffer 20 Relay processing means 23 for performing processing.

  The CPU 12 monitors the communication load factor in the communication lines 3A to 3D connected to the ports 10a to 10d from the states of the ports 10a to 10d from the program P0 for initial setting of the relay processing unit 11 described in detail above. A communication load factor monitoring program P1 that realizes a load factor monitoring unit and a transmission management unit that relays and transmits a message m that can be transmitted using the buffer management unit 21 when the ports 10a to 10d are in a transmittable state. The transmission management program P2 to be executed is executed.

  These programs P1 to P2 are recorded in the ROM 13 that can be read by the CPU 12, but are executed by the CPU 12 to function as communication load factor monitoring means and transmission management means. Further, these means P1 and P2 may be configured not only by software executed by the CPU 12 but also by hardware functional blocks. In this case, the memory embedded logic IC configuring the relay processing unit 11 is included in the means. It is also possible to form. Therefore, in the following description, they are expressed as communication load factor monitoring means P1 and transmission management means P2, respectively.

  The buffer 20 is a memory configured such that a message m to be transmitted / received can be read / written in bit units, and is formed by aggregating memory cells (bit storage elements) such as flip-flops. It is a functional block configured to be able to read and write bit information simultaneously. However, even if the RAM having the number of address buses corresponding to the number of the ports 10 is formed, the RAM formed to have a plurality of address buses in a pseudo manner by time division processing, and these Any of the RAMs having the required number of address buses may be used depending on the combination.

  When receiving the message m from each port 10, the buffer management means 21 searches the slot area SL where there is a free space and uses it as a reception buffer, and records the message m being received one by one. The slot region SL in the middle is also used as a transmission buffer for the message m to be output to the relay destination port 10, and the bit information in the slot region SL is output at a speed required by each port 10a to 10d. When the received message m is received up to the identification information and recorded in the corresponding slot area SL, the identification information reception completion signal r1 is output to the relay processing means 23, and the relay destination port of the message input from the relay processing means 23 The relay channel information Ch including 10 and the relay start time is recorded in the slot area SL.

  In addition, when storing the received message m in the empty slot area SL, the buffer management means 21 stores information indicating that this is in use for the slot area SL, and relaying is performed after the relay transmission of the message m. The information of the completed relay destination port is deleted, and the slot area of the message m in which the relay destination port has disappeared is released as an empty slot.

  FIG. 4 is a view showing a management state of the slot area SL by the buffer management means 21. As shown in FIG. As shown in FIG. 4, in each slot area SL1, SL2,..., The position information Bs of the previous slot area and the position information Ns of the next slot area are recorded in addition to the message m and the relay channel information Ch. The slot areas SL in use (SL9 → SLA → SL2 →... → SLx in the example of FIG. 4) are managed so as to be connected in a chain. Also, unused slot areas SL (SL1 → SL3 → SL4 →... In the example of FIG. 4) are managed so as to be linked in a similar manner. In the slot area SL0 that manages these slot areas SL, the leading position Ts, the trailing position Ls, the leading position Fs of the empty slot area SL, and the like are recorded.

  The relay information recording means 22 is a memory configured so as to be readable at high speed, and has a bus that can be accessed at high speed with a portion storing identification information in the buffer 21.

  FIG. 5 is a diagram showing an example of the relay information T recorded in the relay information recording means 22. As shown in FIG. 5, the relay information T stores relay channel information Ch in which relay instructions Cha to Chd to the relay destination ports 10a to 10d are recorded in association with the identification information ID of each message m. Each relay instruction Cha to Chd includes information indicating the relay start time.

  For example, in FIG. 5, the message m having the identification information ID “0001” or “0002” is relayed using the ports 10a, 10c, and 10d as relay destinations, and is the fastest relay to the relay destination ports 10a and 10d. In contrast to the cut-and-through relay, the relay destination port 10c is set to perform relay after completion of reception, that is, store-and-forward relay. Further, since the port 10b is the port 10 that receives this message m, it is set not to be relayed. On the other hand, the message m having the identification information ID “0003” is set so that only the port 10c is the relay destination.

  As shown in this embodiment, by recording only the identification information ID of the message m to be relayed as the relay information T, the capacity of the relay information recording means 22 can be reduced, but the relay information recording means 22 The relay channel information Ch of all identification information IDs may be recorded in In this case, it is possible to extract the relay channel information Ch using the identification information ID as a direct memory address.

  The relay processing means 23 is a functional block of a logic circuit configured to be able to access the buffer 20 and the relay information recording means 23 at high speed. When receiving the identification information reception completion signal r1 from the buffer management means 21, the relay processing means 23 And a logic circuit such as a comparator for comparing the identification information of the message m and the identification information recorded in the relay information T in the relay information recording means 22. Thereby, the relay processing means 23 is configured to be able to search the identification information of the received message m from the identification information ID recorded in the relay information T at high speed and determine whether or not this is a relay target. Yes. Further, the relay processing means 23 is configured to use the relay information T to determine the relay start time at the relay destination port 10 and the ports 10a to 10d.

  The communication load factor monitoring unit P1 monitors the communication load factor in the communication lines 3A to 3D connected to the ports 10a to 10d, and indicates that the load factor is excessive when the communication load factor exceeds a threshold value. The warnings Wta to Wtd are output to the relay processing means 23. The transmission management means P2 outputs transmission request signals Rsa to Rsd to the buffer management means 21 when the ports 10a to 10d are in a transmittable state.

  Next, the operation of the relay connection unit configured as described above will be described with reference to FIGS. The examples shown in FIGS. 6 and 7 show an example in which reception of the message m including the data D1 is started via the port 10b at the time point t0. When the port 10b receives the message m from the communication line 3B, the buffer management means 21 secures one of the empty slot areas SL and registers it as in use. That is, the position information Bs of the previous slot area and the position information Ns of the next slot area are stored so as to be added to the chain of in-use slot areas SL shown in FIG. 4, and the pieces of information Ts, Ls and Fs are adjusted as necessary.

  Next, at the time t1 when the reception of the identification information ID (“0001” in the example of FIG. 6) of the received message m is completed, the buffer management unit 21 outputs the identification information reception completion signal r1 to the relay processing unit 23 and relays it. The processing means 23 searches the identification information ID in the slot area SL and the relay information T shown in FIG. 5 and outputs the relay channel information Ch to the buffer management means 21. Here, the buffer management means 21 can record the relay channel information Ch in the slot area SL.

  On the other hand, the transmission management means P2 monitors the states of the ports 10a to 10d and outputs the transmission request signals Rsa to Rsd when they are in a transmittable state. As for the relay destination ports 10a and 10d for which "" is set, transmission is started as soon as the relay channel information Ch is recorded in the slot area SL. That is, relay to the relay destination ports 10a and 10d is performed from the relay start time t1 as early as possible, and the message m being received is relayed and transmitted sequentially to the relay destination ports 10a and 10d by parallel processing (cut and through method). ).

  However, for the relay destination port 10c, the relay management means 23 sets “relay after completion of reception”, so that the relay to the relay destination port 10c receives the message m to the end and receives it at the end of the message m. Only the correctly received message is relayed at time t2 when error detection is performed using the error detection code CRC. In other words, the relay to the relay destination port 10c is performed from the relay start time t2 after confirming that the message m has been correctly received (store and forward method).

  Here, as further enlarged in FIG. 7, the message m received via the port 10b cannot be received correctly due to the influence of noise N or the like, and the data D1 included in the message m is inaccurate data D1! Therefore, the relay to the relay destination ports 10a and 10d is performed by the cut-and-through method, so that inaccurate data D1! The message m including is relayed as it is. On the other hand, since the relay to the relay destination port 10c is performed by the store & forward method, the data D1 determined to be inaccurate at the relay start time t2 is not relayed.

  Therefore, inaccurate data D1! Since a useless message m including “” is not transmitted, it is possible to prevent the communication load factor in the communication line 3C connected to the port 10c from being raised unnecessarily. As described above, since the relay start points t1 and t2 are set for each of the ports 10a to 10d by the relay processing unit 23, the relay start point can be adjusted according to the communication status of each of the communication lines 3A to 3D. In the case of the communication line 3C that needs to reduce the communication load factor rather than improving the relay speed, it is possible to perform store-and-forward relaying.

  The relay start time may be dynamically adjusted according to the communication status of each of the communication lines 3A to 3D. That is, when the communication load factor in the communication line 3A connected to the port 10a temporarily increases as in the example shown in FIG. 6, the communication load factor monitoring unit P1 monitors the increase in the communication load factor. Then, by outputting the load factor warning Wta to the relay processing unit 23, the relay of the message m temporarily using the relay destination port 10a is performed by the store & forward method instead of the cut & through method. It is also possible to set the start time from time t4 when the identification information can be received to time t5 when the entire message m can be received.

  By using the relay connection unit 1a configured as described above, it is possible to relay the communication line 3 with an increased communication load factor after confirming that the message m to be relayed is accurate. Thus, it is possible to prevent a situation in which the waiting time of the other ECU 2 that transmits and receives the message m using this communication line is lengthened.

  Since the buffer 20 has a common reception buffer and transmission buffer, it is only possible to prevent the size of the buffer 20 from increasing proportionally even if the number of ports 10 provided in the relay connection unit 1a increases. In addition, it is possible to perform relay transmission of the message m being received by parallel processing without waste. Further, since the functional blocks constituting the buffer management means 21 manage the slot areas SL and the empty slot areas in use so as to connect the slot areas SL in a chained manner, the hardware functional blocks enable high speed operation. In addition, each slot area SL can be appropriately managed.

  8-10 is a figure explaining the structure of the relay connection unit 1 which concerns on 2nd Embodiment (Hereinafter, the relay connection unit 1 of 2nd Embodiment is represented by the code | symbol 1b.). The second embodiment shown in FIGS. 8 to 10 is different from the first embodiment shown in FIGS. 1 to 7 in that the relay processing means 23 relays not for each port 10a to 10d but for each identification information ID of each message m. A point that determines a starting time point, and when each message m is received in the relay processing unit 11, the accuracy of the message is confirmed to monitor the relationship between the identification information of the message m and the error rate, An error rate monitoring means 24 is provided that enables the relay start time to be dynamically adjusted so that a message having identification information with a high error rate can be relayed after confirming that the message has been correctly received.

  The error rate monitoring means 24 can adjust the relay start time for each identification information ID by changing the relay information T recorded in the relay information recording means 22 already described in detail with reference to FIG. .

  Therefore, for example, as shown in FIG. 9, even when the reception of the message m from the port 10b is started at the time point t0 and the relay is started for the relay destination ports 10a and 10d at the relay start time point t1, Incorrect data D1 in this message m! Is included, the error rate monitoring unit 24 monitors the error rate for the identification information ID of the message m, and changes the relay information T when the error rate is equal to or greater than a predetermined threshold.

  Therefore, when the message m having the same identification information ID is received at the time t3 after the relay information T is adjusted, the relay start time to all the relay destination ports 10a, 10c, 10d is the time when the reception of the message m is completed. It is changed to t5. In the example shown in FIG. 9, since it is determined that there is an error in the message m at time t5, relay transmission is not performed for any of the relay destination ports 10a, 10c, and 10d.

  As described above, according to the relay connection unit 1b of the present embodiment, in the case of the message m that needs to be relayed as soon as possible according to the type of the message m, the cut-and-through fastest relay is performed, If accuracy is a priority, store-and-forward forwarding can be performed. Further, by monitoring the error rate for each identification information ID by the error rate monitoring means 24 and adjusting the relay start time, when relaying the message m from the ECU 2 frequently sending the error message, It is also possible to relay after confirming the accuracy, and the reliability of the relay connection unit 30 can be improved.

  In the present embodiment, the relay processing means 23 determines the relay start time for each identification information ID of each message m, not for each port 10a to 10d so that the gist of the invention becomes clear. The relay processing means 23 may determine a relay start time for each port 10a to 10d or / and for each identification information ID of the message m. That is, the relay connection unit 1b of the second embodiment and the relay connection unit 1a of the first embodiment can be realized by one relay connection unit 1.

  FIGS. 10-12 is a figure explaining the relay connection unit 1 which concerns on 3rd Embodiment (Hereinafter, the relay connection unit 1 of 3rd Embodiment is represented using the code | symbol 1c). In this embodiment, the difference from the first embodiment and the second embodiment shown in FIGS. 1 to 9 is that the relay processing means 23 starts the relay according to the ratio of the communication speed of the relay source port and the communication speed of the relay destination port. The point is to adjust the time. Further, as shown in FIG. 10, the buffer management means 21 is configured to output reception completion signals r1, r2,... At a plurality of stages according to the reception status of the message m to the buffer 20.

  FIG. 11 shows an example of the relay information T ′ recorded in the relay information recording means 22. The relay information T ′ shown in FIG. 11 differs from the relay information T shown in FIG. 5 in that the relay start time when the message m having the identification information ID “0007” is relayed to the relay destination port 10 b is “50% reception relay”. It is a point. This is a relay start time setting in accordance with the communication speed of the relay destination port 10b being double the communication speed of the relay source port 10d.

  FIG. 12 is a diagram for explaining the operation when the message m having the identification information ID “0007” is received from the port 10d. When reception of the message m is started at time t6, reception of the identification information ID of the message m is completed at time t7. However, as indicated by a virtual line, when relay to the relay destination ports 10b and 10c is started from this time t7, there arises a problem that reception of the message m to be relayed is not in time for relay transmission.

  Therefore, when relaying to the port 10b having the double communication speed, the relay processing unit 23 can set “50% reception relay” with the relay start time after time t8 when reception of 50% or more of all messages m is completed. It is configured. That is, the relay start time is time t7 when the identification information is received when the communication speed of the relay destination port is equal to or lower than the communication speed of the relay source port, and the communication speed of the relay destination port is When the communication speed of the relay source port is faster, the time when the message transmission completion time t9 to the relay destination port is adjusted to be after the message reception completion time t10 from the relay source port (see FIG. In the case of 12, the time is 50% reception time t8 or later).

  Further, since the relay destination port 10c has a communication speed four times faster than the relay source port 10d, the relay start port 10d is set in the buffer 20 by setting the relay start time to the relay destination port 10d after the reception completion time t10. The relay transmission is started after the message m to be relayed is secured.

FIG. 13 is a diagram showing the relationship between the communication speed ratio of the relay destination port to the relay source port and the minimum reception amount [%] at the relay start time. As shown in FIG. 13, in order for the message transmission completion time to the relay destination port to be later than the message reception completion time from the relay source port, the relay destination for the communication speed of the relay source port is used. It can be seen that the relay start time can be determined from the ratio of the communication speeds of the ports. Further, the curve portion in FIG. 13 has the relationship shown in the equation (1).
Received amount at start of relay [%] = 100 (1- (relay destination transfer rate) / (relay source transfer rate)) (1)

  By using the relay connection unit 1c configured as described above, it is possible to perform relay transmission in a state where the message m to be relayed is reliably stored in the buffer 20, so that the reliability of the relay connection unit 1 is improved. Message m can be relayed as fast as possible. Further, the relay connection unit 1c shown in the third embodiment can also be realized by one relay connection unit 1 in combination with the relay connection units 1a and 1b of the first embodiment and the second embodiment.

It is a block diagram of the vehicle-mounted LAN using the relay connection unit of this invention. It is a block diagram of the relay connection unit which concerns on 1st Embodiment. It is a block diagram which shows the structure of the said relay connection unit. It is a figure explaining the management of the buffer in the said relay connection unit. It is a figure which shows an example of relay information. It is a figure explaining the example of communication using the said relay connection unit. It is a figure which shows the detail in the example of the said communication. It is a figure explaining the structure of the relay connection unit which concerns on 2nd Embodiment. It is a figure explaining the example of communication using the said relay connection unit. It is a figure explaining the structure of the relay connection unit which concerns on 3rd Embodiment. It is a figure which shows the example of the relay information in the said relay connection unit. It is a figure explaining the example of communication using the said relay connection unit. It is a figure which shows the relationship between the communication speed ratio of a relay source and a relay destination, and a relay start time. It is a figure which shows the structure of the conventional relay connection unit.

Explanation of symbols

1 (1a, 1b, 1c) Relay connection unit 2 (2A, 2B ...) ECU
3 (3A, 3B...) Communication line 10 (10a, 10b...) Port 20 Buffer 21 Buffer management means 22 Relay information recording means 23 Relay processing means 24 Error rate monitoring means P1 Communication load rate monitoring means P2 Transmission management means ID identification information T, T ′ relay information t1, t2, t4, t5, t8 Relay start time t10 Reception completion time SL (SL1, SL2...) Slot area

Claims (7)

A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparison with the identification information recorded in the relay information recording means, and the message in the buffer for each relay destination port The relay start time for starting the relay transmission of the message is determined, and the message in the buffer is relayed and transmitted to a certain relay destination port after receiving the message and confirming the accuracy of the message. A relay connection unit, comprising: relay processing means for relaying and transmitting messages stored in the buffer one by one from the time when a relay destination port of a message being received can be determined. Communication load factor monitoring means for monitoring the communication load factor in the communication line connected to each port,
2. The relay according to claim 1, wherein the relay processing means relays the message after confirming the accuracy of the message when a port connected to a communication line having a high communication load factor is used as a relay destination port. Connection unit. A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparison with the identification information recorded in the relay information recording means, and relay transmission is started for each identification information The relay start time is determined, and the message in the buffer is relayed and transmitted after confirming the correctness of the message for the message of certain identification information, while the message of another identification information is being received. A relay connection unit, comprising: a relay processing unit that relays and transmits a message in the buffer from the time when a message relay destination port can be determined.   After the message is received, the accuracy of the message is confirmed to monitor the relationship between the identification information of the message and the error rate, and after confirming that the message having the identification information with a high error rate has been received correctly The relay connection unit according to claim 3, further comprising an error rate monitoring unit that dynamically adjusts the relay start time so as to relay the message. A plurality of in-vehicle LAN communication means connected to a plurality of communication lines to transmit and receive messages; and
A buffer for storing messages received via the port bit by bit;
A relay information recording means for recording the relationship between the identification information of the message that needs to be relayed and the relay destination port;
When the identification information of the received message is received, the relay destination port corresponding to the identification information is determined by comparing with the identification information recorded in the relay information recording means, and the relay source port and the relay destination of the message A relay connection unit comprising: a relay processing unit that determines a relay start time for starting relay transmission in accordance with a ratio of communication speeds of ports, and relays and transmits a message in the buffer to a relay destination port.   The relay start time is a time when the identification information is received and the relay destination port can be determined when the communication speed of the relay destination port is equal to or lower than the communication speed of the relay source port. When the communication speed is higher than the communication speed of the relay source port, the time when the message transmission completion time to the relay destination port is adjusted to be later than the time when the message reception from the relay source port is completed The relay connection unit according to claim 5, wherein Buffer management means for managing the storage area in the buffer divided into a plurality of slot areas;
Transmission management means for relaying and transmitting a message corresponding to the transmittable port using a buffer management means when each port is in a transmittable state,
The buffer management means includes
When a message to be stored in the buffer is received from each port, the slot area in which an empty space is generated is searched, information indicating that the slot area is in use is stored, and then the slot area is stored. While storing the message being received one by one, and storing the relay destination port and the relay start time of the message determined by the relay processing means when the identification information of the message has been stored,
When receiving a request for relay transmission of a message from the transmission management means, a slot area for storing a message to be output to a relay destination port that is in a transmittable state by sequentially tracing each slot area in use After searching and relaying the message stored in the slot area to the relay destination port, the relay destination port information in the slot area is deleted, and
The slot area is released by storing that the slot area is an empty slot when there is no relay destination port stored in the slot area. The relay connection unit described.

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