JP2014072673A - Relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repeating device capable of relaying data for an ECU connected to a network to an external apparatus without the need for watching a load.SOLUTION: Provided is a relay device 100 for relaying data from an intra-vehicle node 12 to the outside of the vehicle via a connecting terminal. The relay device 100 comprises: reception storage means 32 for storing data received from the node; transmission storage means 31 for storing the data to be transmitted to the connecting terminal; data relay means 37 for relaying data from the reception storage means to the transmission storage means; a priority table 30 having information on data priority registered therein; overwrite detection means 34 for detecting that the data of the reception storage means is overwritten with the data transmitted from the node; and data thinning-out means 35 for thinning out the data to be relayed by the data relay means when the overwrite detection means has detected an overwrite and also increasing the data to be thinned-out in order beginning with the data having low priority each time the overwrite detection means detects an overwrite.

Description

  The present invention relates to a relay device that relays data from a plurality of nodes mounted on a vehicle to devices outside the vehicle.

  Many electronic control units (hereinafter referred to as ECU: Electronic Control Unit) are mounted on the vehicle, and each ECU can communicate via a network such as a CAN (Controller Area Network). There is a request to check the data transmitted from the ECU over the network and the stored information from the outside. Conventionally, the DLC (Data Link for connecting external devices (scan tools) to the network in the driver's seat of the vehicle, etc. Connecter) is placed.

  FIG. 1 is an example of a diagram schematically illustrating a conventional in-vehicle network and an ECU. Since a plurality of ECUs are connected to the DLC, the external device can receive data transmitted by the ECU simply by connecting the external device to the DLC. However, the network is divided into several buses by GWs (gateway devices) 1 and 2 in order to distribute the bus load, and it is difficult for the external device to receive data from the ECU ahead of GW1. Or, if not difficult, a complicated operation is required.

JP 2011-61415 JP 2006-287738 A

  Therefore, it is conceivable to newly provide a new relay device that relays data to an external device. FIG. 2 is an example of a diagram schematically illustrating the external device and the gateway ECU. The gateway ECU 100 is a relay device that transmits data from the plurality of buses 1 to n to the external device 200 and from the external device 200 to the buses 1 to n. By arranging the gateway ECU 100, the external device 200 can transmit and receive data as long as the ECU is connected to the gateway ECU 100.

  However, when the ECU of each bus is connected to one gateway ECU in this way, the load on the gateway ECU 100 increases. For such inconvenience, it is considered to select data to be relayed according to the load of the gateway ECU 100 (see, for example, Patent Document 1). Patent Document 1 discloses a communication relay device that selects an inspection process to be performed on data to be relayed among a plurality of inspection processes, depending on which stage the load of the arithmetic processing unit is. However, in this case, it is necessary to monitor the load of the arithmetic processing means, and there is a risk of pressing the original relay processing that the gateway ECU 100 should perform.

  Further, a technique for adjusting the bus load when the bus load becomes high instead of the gateway ECU 100 (see, for example, Patent Document 2). However, in this case, the processing for calculating the bus load is required, and the higher the bus load, the more likely the processing to calculate the bus load tends to be deprived of the ability.

  An object of the present invention is to provide a relay device that can relay data of an ECU connected to a network to an external device without monitoring a load.

  The present invention is a relay device that relays data from a plurality of nodes mounted on a vehicle to the outside of the vehicle via a connection terminal, and stores the data received from the node, and transmits the data to the connection terminal. Storage means for storing the data to be performed, data relay means for relaying the data from the storage means for reception to the storage means for transmission, a priority table in which priority information of the data is registered, and Overwrite detection means for detecting that the data in the storage means for reception is overwritten by the data transmitted from the node, and relay for relaying by the data relay means when the overwrite detection means detects overwriting The target data is thinned out, and each time the overwrite detection unit detects overwriting, the data to be thinned out in order from the lower priority data. And having a data thinning means to increase.

  It is possible to provide a relay device that can relay data of an ECU connected to a network to an external device without monitoring a load.

It is an example of the figure which shows the conventional vehicle-mounted network and ECU typically. It is an example of the figure which illustrates an external device and gateway ECU typically. It is an example of the figure explaining the relay of data by gateway ECU of this embodiment. It is an example of the hardware block diagram of gateway ECU. It is a figure which shows an example of a data frame. It is an example of a functional block diagram of a gateway ECU. It is a figure which shows an example of the transfer management table. It is an example of the flowchart figure which shows the procedure until a transfer process part starts a transfer process. It is a figure which shows an example of a priority table. It is an example of the flowchart figure which shows the transfer procedure of the CAN frame by gateway ECU. It is a figure which shows an example of a priority table etc. It is a figure which shows an example of a priority table. It is an example of the figure which illustrates typically the CAN frame received from an external device, and the CAN frame which gateway ECU transfers. It is an example of a functional block diagram of a gateway ECU. It is an example of the flowchart figure which shows the transfer procedure of the CAN frame by gateway ECU.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to this embodiment.

  FIG. 3 is an example of a diagram illustrating data relaying by the gateway ECU according to the present embodiment. As shown in FIG. 3 (a), each ECU 12 (in the case of distinction, “bus number-serial number” is assigned to the ECU) transmits data at an arbitrary timing. The gateway ECU 100 has at least one reception buffer for each bus, and transmits data stored in the reception buffer to the DLC side. Priorities are determined in advance for the ECU 12, data, or buses 1 to n. This priority order is a priority order for selecting data to be preferentially transmitted to the external device 200. Here, for the sake of simplicity, it is assumed that priorities are determined for each bus. The smaller the number, the higher the priority.

  As shown in FIGS. 3A and 3B, the bus load may increase due to an increase in the data transmission frequency of each ECU. Data is already stored in the reception buffer of each bus, and data that has not yet been transmitted is stored in the transmission buffer. For this reason, the data in the reception buffer may be overwritten before the data in the reception buffer is transferred to the transmission buffer. The gateway ECU 100 detects this overwriting and performs a data thinning process. The thinning process refers to not relaying data from the bus side to the DLC 11. Hereinafter, it may be simply referred to as “thinning”.

  The gateway ECU 100 performs the thinning process in order from the data with the lowest priority. In FIG. 3C, data n-1 and n-3 are thinned out. Regardless of the priority order, the relay processing performed by the gateway ECU 100 for one piece of data is the same, so that it is expected that the load is reduced and the frequency of overwriting the data in the reception buffer is reduced by thinning out the data. Thereafter, the gateway ECU increases the data to be thinned every time it detects overwriting of data in the reception buffer. Although there are various specific modes of the thinning process, the data on the bus 3 may be thinned every other time, or all the data on the bus 3 may be thinned out.

  In this way, by repeating the overwriting detection and the data thinning-out process, it is possible to gradually suppress an increase in load and reduce overwriting while preferentially transmitting high priority data to the external device 200. Further, since it is not necessary to monitor the processing load of the gateway ECU 100, it is possible to reduce the pressure on the transfer processing of the gateway ECU 100.

[Configuration example]
The in-vehicle system 300 according to the present embodiment will be described with reference to FIG. One or more ECUs 12 are connected to the buses 1 to n. Compared with the case where all ECUs 12 are compared with one bus, the bus load can be reduced. In the figure, a GW (gateway) responsible for data transfer between buses is not described separately from the gateway ECU 100, but a GW (not shown) is arranged, the gateway ECU 100 is also used, or a certain ECU 12 has a function of the GW. Also serves as.

  For example, an engine ECU, a smart key ECU, an airbag ECU, a body ECU, a power steering ECU, a meter ECU, a skid control ECU, and a power management ECU are connected to the bus 1. Note that not only the ECU 12 but also a sensor may be connected. For example, a driving support ECU, a parking support ECU, a seat belt ECU, a clearance warning ECU, a headlamp swivel ECU, and the like are connected to the bus 2. An engine ECU, a driving support ECU, and a skid control ECU are connected to the bus 3.

  Each ECU 12 has a difference in configuration due to a difference in processing capability, but has a CPU 22, a RAM 23, a ROM 24, a microcomputer having an I / O and a CAN controller, a power supply circuit, a connector for connecting a wire harness, and the like. .

  The DLC 11 is a connector in which a physical shape, an electrical signal, and a pin assignment for mounting the external device 200 are defined. For example, these are defined by OBD (On Board Diagnostic System) II. The OBDII further defines the data requested by the external device 200 as a CANID described later, and the external device 200 can receive the requested data from the ECU that has received the CANID. That is, the external device 200 can communicate with the ECU connected to the vehicle network via the DLC 11.

  FIG. 4 shows an example of a hardware configuration diagram of the gateway ECU 100. The gateway ECU 100 is connected to the bus 28, the CPU 22, the RAM 23, the ROM 24, and a plurality of CAN controllers 21, 25 to 27 (hereinafter, CAN controllers connected to the buses 1 to n are connected to the CAN controllers 1 to n and DLC, respectively. The prepared CAN controller is called a CAN controller S). Configurations not used in this embodiment are omitted. The CPU 22 expands and executes the program stored in the ROM 24 in the RAM 23 and executes processing such as data thinning described later. The CAN controllers 1 to n are provided for each bus. The CAN bus transmits two logic lines H and L as a pair and transmits a logic level (H or L) by the differential voltage. The same differential voltage is transmitted to all ECUs 12 connected to the buses 1 to n. Further, the ECU 12 that has transmitted the data can monitor (receive) its own data being transmitted.

  The CAN controller performs control related to data transmission. At the time of reception, the CAN controller converts the differential voltage flowing through the buses 1 to n into a digital signal by a transceiver (not shown). The CAN controllers 1 to n perform reception judgment, ACK response, error detection, and the like on this digital signal. During transmission, the CAN controller sets CANID, creates a CAN frame, arbitrates, and the like, and the transceiver converts the logic level to a differential voltage.

<CAN frame>
Data flowing through the CAN is called a CAN frame, and there are four types of data frames, remote frames, error frames, and overload frames, each of which has a predetermined format. Mainly used are a data frame for transmitting data and a remote frame for requesting data.

  FIG. 5 is a diagram illustrating an example of a data frame. SOF indicates the head of the CAN frame. CANID is an identifier for identifying data, and is also used when arbitrating the right to use the bus. RI, TDr, and RE0 are control bits and are fixed values. DLC 11 indicates the length of data stored in the data frame. Data to be transmitted is stored in DATA. CRC is a cyclic redundancy code for error detection. The next 1 bit of the CRC is called a CRC delimiter and is a delimiter bit. The ACK slot is 1 bit for the reception side ECU to transmit normal reception. When the transmission-side ECU transmits the ACK slot recessively (1: recessive), the reception-side ECU sets a dominant (0: dominant) in the ACK slot. In some cases, this dominant setting returns an ACK. The ACK delimiter is 1 bit for delimiter. EOF indicates completion of transmission. The remote frame is the same as the data frame except that there is no DLC 11 and DATA.

  In each CAN controller register, a CANID to be received when the gateway ECU 100 is activated is registered. The CAN controller monitors the CAN ID of the CAN frame flowing through the buses 1 to n, and receives it when it is a registered CAN ID. At this time, the ACK slot is set to dominant. Thereby, the ECU on the transmission side can detect that the CAN frame has been normally received.

  When the CAN controllers 1 to n receive the CAN frame, the necessary fields are extracted from the CAN frame and stored in the reception buffer. The field to be extracted is, for example, CANID to CRC, but the data stored in the reception buffer is also referred to as a CAN frame.

[About functions]
FIG. 6 shows an example of a functional block diagram of the gateway ECU 100. It has a reception buffer 32 (hereinafter referred to as reception buffers 1 to n when distinguished) and a transmission buffer 31 (hereinafter referred to as transmission buffers 1 to n when distinguished). The reception buffer 32 is an area of a predetermined address in the RAM 23 or a memory prepared in the CAN controllers 1 to n. As many reception buffers as the number of CAN controllers 1 to n are prepared. A plurality of transmission buffers 31 are provided in consideration of the number of reception buffers 32. In the figure, the number is equal to the number of buses 1 to n, but may be less than n or more than n.

  The reception detection unit 33, the overwrite determination unit 34, the data thinning unit 35, and the transfer processing unit 37 are realized by the CPU 22 executing a program in cooperation with hardware such as a DMAC (Direct Memory Access Controller) or an interrupt controller. The

  The reception detection unit 33 detects that the CAN controller has received the CAN frame by using the reception interrupt to notify the CPU 22 that the CAN controllers 1 to n have received the CAN frame. At the time of interruption, the reception detection unit 33 determines the bus number from the identification information of the CAN controllers 1 to n. The reception detection unit 33 notifies the detection of the interruption and the bus number to the overwrite determination unit 34 and the transfer processing unit 37.

  The overwrite determination unit 34 refers to the transfer management table 36 and determines whether or not the transfer of the CAN frame of each reception buffer received in the past is completed.

  FIG. 7 is a diagram illustrating an example of the transfer management table 36. An untransfer flag is registered in association with the bus number. The untransfer flag is “1” until transfer and becomes “0” by transfer. The overwrite determination unit 34 determines that the overwrite has occurred when the untransfer flag of the bus number notified from the reception detection unit 33 is “1”. When the untransfer flag of the bus number notified from the reception detection unit 33 is “0”, it is not determined that overwriting has occurred and the untransfer flag is set to “1”. The overwrite determination unit 34 notifies the data thinning unit 35 when overwriting is detected. A plurality of reception buffers 32 may be prepared for one bus.

<Transfer processing>
Returning to FIG. 6, the transfer processing unit 37 starts the transfer process when detecting that the external device 200 is connected. When the external device 200 is connected, the transfer processing unit 37 performs a transfer process of specifying the reception buffers 1 to n by the bus number notified from the reception detection unit 33 and transmitting the stored CAN frame to the DLC side. Do.

  FIG. 8 is an example of a flowchart illustrating a procedure until the transfer processing unit 37 starts the transfer process.

  The transfer processing unit 37 periodically transmits a test signal from the DLC side (S10). The test signal has a CANID that can be received by the external device 200, and if the external device 200 is connected, the external device 200 may be a CAN frame that sets a dominant in the ACK slot (returns ACK). That is, it is not necessary (may be stored) to store data to be transmitted to DATA. The transfer processing unit 37 designates such a CANID and makes a transmission request to the CAN controller S. Thereby, the CAN controller S creates a CAN frame and transmits it to the DLC side.

  The transfer processing unit 37 determines whether or not the CAN controller S detects ACK (S20). When ACK is not detected (No in S20), nothing is connected to the DLC 11, and therefore the transfer processing unit 37 repeats the processes of S10 and S20.

  When the CAN controller S detects ACK (Yes in S20), the transfer processing unit 37 determines that the external device 200 is connected to the DLC 11 (S30).

  As a result, the transfer processing unit 37 starts relaying data stored in the reception buffers 1 to n (S40). From the viewpoint of the user using the external device 200, data can be received simply by connecting the external device 200 to the DLC 11, so that the operability of the external device 200 is improved. A data transmission request may be transmitted from the external device 200 to the gateway ECU 100, and the transfer processing unit 37 may start data relay when the transmission request is received. In this way, power consumption can be reduced.

  The relay process is performed, for example, by specifying the CAN ID of the CAN frame stored in the reception buffers 1 to n to the CAN controller S, storing the data in DATA in the transmission buffers 1 to n, and instructing transmission. . If necessary, the data in DATA may be processed, or CANID conversion may be performed. In this case, the transfer processing unit 37 has a correspondence table of CANIDs before and after conversion.

  Further, the transfer processing unit 37 may authenticate the external device 200. For example, when the external device 200 stores the license information, it is determined that the authentication is established, and when the authentication is established, the CAN frame is relayed. Alternatively, the CAN frame to be relayed may be limited when authentication is not established.

  When the transfer processing unit 37 relays the CAN frame from the reception buffers 1 to n to the transmission buffers 1 to n, the transfer processing unit 37 sets “0” in the untransfer flag of the transfer management table 36. Thus, since the untransfer flag indicates whether or not the transfer has been completed, the overwrite determination unit 34 can determine whether or not there is an overwrite.

<Thinning out CAN frame>
The data thinning unit 35 instructs the transfer processing unit 37 to thin the CAN frame when overwriting is detected. In order to determine data to be thinned out, the transfer processing unit 37 can refer to the priority table 30.

  FIG. 9 shows an example of a priority table. In the priority table 30, bus numbers are associated with priorities. That is, the CAN frame of bus 1 has the highest priority, and the CAN frame of bus n has the lowest priority.

The transfer processing unit 37 thins out the CAN frame by sequentially excluding the CAN frame of the bus having the lower priority order from the relay target in accordance with the overwrite frequency. The rules for determining the CAN frame to be thinned are as follows.
(i) 1 level for increasing the priority of the CAN frame to be thinned every time overwriting is detected (first overwriting detection) → 2 levels for thinning every other CAN frame of bus n (second overwriting detection) → Thin out every other CAN frame on bus n-1:
n level (n-th overwriting detection) → n + 1 level of thinning out every CAN frame of bus 1 (n + 1 overwriting detection) → thinning out CAN frame of bus n twice in 3 times:
Alternatively, the CAN frame of the entire bus can be thinned out 1 level (first overwriting detection) → 2 levels not transmitting all CAN frames of bus n (second overwriting detection) → all CAN frames of bus n−1 Do not send:
n level (nth overwriting detection) → Do not send all CAN frames on bus 1
(ii) Every time overwriting is detected, the frequency of thinning out from a low priority bus is increased, and when the frequency of thinning exceeds a threshold value, the frequency of thinning out is increased for the bus with the next highest priority (1 (Overwrite detection at the second time) → Two levels of thinning out every CAN frame of bus n (second overwriting detection) → Three levels of thinning out CAN frame of bus n twice every three times (third overwriting detection) → 4 levels to thin out CAN frame of bus n 3 times 4 times (4th overwriting detection) → 5 levels to thin out every other CAN frame of bus n-1 (5th overwriting detection) → bus n-1 Thinning out CAN frames twice in 3 times:
In both cases (i) and (ii), at the k level, the CAN frame defined by the level of k-1 or lower is continuously thinned out.

  Thus, every time overwriting is detected in the thinned state, the thinning level increases and the number of CAN frames to be thinned increases. (i) (ii) Which rule is adopted is set in the transfer processing unit 37 based on the CAN frame flowing through the bus. The rules for thinning out are arbitrary, such as combining (i) and (ii), adopting (ii) for any bus, and adopting (i) for other buses.

  The data thinning unit 35 instructs the transfer processing unit 37 on the above level. The transfer processing unit 37 instructed to thin out the CAN frame determines the bus number to be thinned out and the CAN frame according to the level. Since the bus to be thinned and the thinning frequency are determined depending on the level, when the CAN controller connected to the bus to be thinned receives a CAN frame, the number is counted. When thinning out every other number, the non-transfer flag of the transfer management table 36 is set to “0” without relaying only when the number is an odd number. Thus, the thinning frequency can be controlled according to the level. Note that such a count is not necessary when the CAN frame of the entire bus is thinned out.

  FIG. 10 is an example of a flowchart illustrating a CAN frame relay procedure performed by the gateway ECU 100. The process of FIG. 10 starts when the transfer processing unit 37 receives an ACK from the external device 200.

  For example, every time the reception detection unit 33 detects reception of a CAN frame, the data thinning unit 35 determines whether overwriting of the CAN frame has occurred (S110). If no overwriting has occurred (No in S110), the transfer processing unit 37 relays the CAN frame (S140).

  When overwriting occurs (Yes in S110), the data thinning unit 35 increases the variable i by one (S120). The variable i is an integer indicating the level of decimation, and “0” means no decimation.

  Next, the transfer processing unit 37 performs i-level thinning (S130). That is, the transfer processing unit 37 determines the buses 1 to n from which CAN frames are thinned out according to the level determined by the variable i and the frequency thereof, and thins the CAN frames by not performing relaying.

  Next, the data thinning unit 35 determines whether or not a predetermined time has elapsed since the last change of level (S150). Here, it is determined whether or not the CAN frame decimation level is restored. If a predetermined time has elapsed since the last increase in level, it means that the predetermined time has elapsed since overwriting is no longer detected, so the thinning-out level is returned to one on a trial basis. Further, when a predetermined time has passed since the level was lowered last, overwriting is not detected at that level, so the thinning-out level is returned to one on a trial basis.

  Therefore, when the predetermined time has elapsed since the level was last changed (Yes in S150), the data thinning unit 35 decreases the variable i by one (S160). As a result, if overwriting is detected, the variable i is increased by one and the thinning level is increased. If the state in which no overwriting is detected is detected for a predetermined time, the variable i is further decreased by one and the thinning level is decreased. In this way, if the bus load decreases, the variable i returns to zero, and the thinning process can be completed.

[Another example of priority group and thinning processing]
Although it has been described above that the priority is determined for each bus, the priority can be set with various granularities.

A. When Priorities are Assigned to Each ECU FIG. 11A shows an example of the priority table 30 when priorities are assigned to each ECU. In FIG. 11A, one or more ECU numbers are associated with the priority order. The ECU number is, for example, unique identification information that does not overlap on a model number or CAN that identifies the ECU.

  When priorities are set in this way, CAN frames of ECUs having different priorities are stored in the same reception buffer. However, since the ECU number is not included in the CAN frame recorded in the reception buffer, the transfer processing unit 37 cannot determine the priority order of the CAN frame in the reception buffer.

  Therefore, the transfer processing unit 37 has an ECU transmission CANID table as shown in FIG. In the ECU transmission CANID table, the CANID transmitted by each ECU is registered. Therefore, the transfer processing unit 37 can specify the ECU number and CANID that are to be thinned out based on the level notified from the data thinning unit 35.

The rules for determining the CAN frame determined by the data thinning unit 35 may be the same as the above (i) and (ii).
(i) 1 level to increase the priority of the ECU group to be thinned out every time overwriting is detected (first overwriting detection) → 2 levels to thin out every other CAN frame of the ECU group with priority n (the second time) Overwrite detection)-> Every other CAN frame of the ECU group with priority n-1 is thinned out:
n level (n-th overwriting detection) → n + 1 level (n + 1-th overwriting detection) thinning out every other CAN frame of the priority 1 ECU group → 2 CAN frames of the priority n ECU group twice , Thin out:
(ii) One level of increasing the frequency of thinning out from the lower priority ECU group every time overwriting is detected, and increasing the frequency of thinning out from the next higher priority ECU group when the frequency of thinning exceeds a threshold (First overwriting detection) → Two levels of thinning out every other CAN frame of the priority n ECU group (second overwriting detection) → Thinning out the CAN frame of the priority n ECU group twice in three times 3 level (3rd overwriting detection) → 3 times in 4 CAN frames of ECU group with priority n, 4 levels to be thinned out (4th overwriting detection) → 1 CAN frame of ECU group with priority n-1 5 levels to be thinned out every other time (fifth overwriting detection) → thinned out CAN frames of ECU group with priority n-1 twice in 3 times:
For example, in the case of (i), the transfer processing unit 37 performs CAN frame thinning as follows.
In the case of the 1st level Since the CAN frame of the ECU group of the priority order n is thinned out at the 1st level, the transfer processing unit 37 specifies the ECU number from the priority order table 30. In this case, ECU1-3, ECU2-3, and ECU3-3 are specified. Next, the CANID is specified with reference to the ECU transmission CANID table. Accordingly, at the first level, 006, 009, and 010 (the ECU2-3 CANID is omitted) are CAN frame CANIDs to be thinned. Therefore, the transfer processing unit 37 checks the CAN ID of the CAN frame stored in the reception buffer, and if it is 006, 009 or 010, it thins out every other one (relays only once every two times).
-In the case of the 2nd level In the 2nd level, the CAN frames of the priority order n-1 and the priority order n are thinned out. In level 2, ECU1-2, ECU2-2, and ECU3-2 are specified. Next, the CANID is specified with reference to the ECU transmission CANID table. Therefore, in the second level, 003, 004, and 005 (CANIDs of ECUs 2-2 and 3-2 are omitted) are CAN IDs of CAN frames to be thinned.

  Accordingly, the transfer processing unit 37 confirms the CAN ID of the CAN frame stored in the reception buffer, and if it is 003, 004 or 005, it thins out every other one (relays only once every two times). Further, since the level 1 thinning process is continued, if it is 006, 009 or 010, every other one is thinned out (relayed only once every two times).

  By doing so, data can be thinned out in units of ECUs. Since the ECU has a function of the same system such as a function of controlling the engine, the CAN frames transmitted from the same ECU may have the same priority. Therefore, the priority order of the CAN frames can be easily managed by assigning the priority order to each ECU.

B. When Priorities are Assigned to Each CANID FIG. 12 shows an example of the priority table 30 when priorities are assigned to each CANID. In FIG. 12, CANID groups are associated with priorities. By associating CANIDs with priorities instead of ECUs, different priorities can be assigned to a plurality of CAN frames transmitted by the same ECU.

  Since the rule for determining the CAN frame determined by the data thinning unit 35 is the same as (i) and (ii) above, the description thereof is omitted.

For example, in the case of (i), the transfer processing unit 37 performs CAN frame thinning as follows.
In the case of the 1st level Since the CAN frame of the CANID group of the priority order n is thinned out at the 1st level, the transfer processing unit 37 specifies the CANID from the priority order table 30. Therefore, in the first level, 009 and 010 are CAN IDs of CAN frames to be thinned out. Therefore, the transfer processing unit 37 checks the CAN ID of the CAN frame stored in the reception buffer, and if it is 009 or 010, it thins out every other frame (relays only once every two times).
In the case of the 2nd level In the 2nd level, CAN frames of the CANID groups with the priority order n-1 and the priority order n are thinned out. In level 2, 008 is the CAN ID of the CAN frame to be thinned.

  Accordingly, the transfer processing unit 37 confirms the CAN ID of the CAN frame stored in the reception buffer, and if it is 008, it thins out every other one (relays only once every two times). Further, since the level 1 thinning process is continued, if it is 009 or 010, every other one is thinned out (relayed only once every two times).

  In this way, data can be thinned out in CANID units. By setting priorities for each ECU, finer data thinning control becomes possible.

  As described above, the gateway ECU 100 according to the present embodiment gradually thins out a CAN frame having a low priority every time overwriting is detected, so that a CAN frame having a high priority can be reliably detected without monitoring the processing load and the bus load. Can be relayed to.

  As described above, the external device 200 may transmit a CAN frame to the gateway ECU 100 in some cases. In this case, when the bus load of the buses 1 to n is high, it is expected that it becomes difficult to transmit the CAN frame to the buses 1 to n.

  FIG. 13 is an example of a diagram schematically illustrating a CAN frame received from the external device 200 and a CAN frame relayed by the gateway ECU 100. In the present embodiment, the constituent elements denoted by the same reference numerals in the first embodiment perform similar functions, and therefore, only the main constituent elements of the present embodiment may be mainly described.

  The CAN frame transmitted by the external device 200 to the buses 1 to n is, for example, a request for data transmission to a specific ECU by a remote frame, or an active test to request the result. The gateway ECU 100 relays the CAN frame transmitted from the external device 200 to all of the buses 1 to n. This is because it is unclear to which bus 1 to n the ECU that responds to the CAN frame transmitted by the external device 200 is connected. For this reason, the bus load of the buses 1 to n increases. Although it is possible for the gateway ECU 100 to associate the CAN ID of the CAN frame received from the external device 200 with the destination bus, the processing load increases by determining the destination.

  Therefore, when receiving the CAN frame from the external device 200, the gateway ECU 100 according to the present embodiment stops the transfer process from the buses 1 to n to the external device 200. Alternatively, thinning is performed as in the first embodiment. On the other hand, since the CAN frame transmitted from the external device 200 and transmitted by the ECU 12 should be transmitted to the external device 200, the CAN frame transmitted to the gateway ECU 100 in response to the ECU is transmitted to the external device 200. By doing so, the external device 200 can reliably transmit the CAN frame to the ECUs of the buses 1 to n and can receive a response.

  FIG. 14 shows an example of a functional block diagram of the gateway ECU 100. 6, a reception buffer 40 is provided on the DLC side, a transmission buffer 41 is provided on the buses 1 to n side, and an external reception detection unit 38 and a bus transmission control unit 39 are provided. The external reception detection unit 38 detects that the CAN controller S has received a CAN frame from the external device 200 by a reception interrupt that has received the CAN frame. Since the external reception detection unit 38 notifies the transfer processing unit 37 and the bus transmission control unit 39 of the reception, the transfer processing unit 37 cancels the relay of the CAN frames of the buses 1 to n or whether or not there is an overwrite. Start thinning regardless of

  When the thinning process is performed instead of canceling the relay, the level can be designated according to the reception amount per unit time of the CAN frame received from the external device 200 instead of the level of the first embodiment.

The bus transmission control unit 39 relays the CAN frame of the reception buffer 40 on the DLC side to the buses 1 to n by storing the CAN frame in the transmission buffer 41. In this case, by transmitting the CAN frames in the order of the buses 1 to n, the gateway ECU 100 can relay the CAN frame transmitted by the ECU that should respond to the CAN frame. For example, the control is performed as follows.
1. The CAN frame is transmitted to the bus 1 in a state where the relay from the buses 2 to n to the external device 200 is stopped. When the ACK is received, the CAN frame is received from the bus 1 and the transfer processing unit 37 is permitted only to relay the bus 1. When ACK is not received, the same transmission process is performed on the bus 2.
2. The CAN frame is transmitted to the bus 2 in a state where the relay from the buses 1, 3 to n to the external device 200 is stopped. When the ACK is received, the CAN frame is received from the bus 2 and only the relay of the bus 2 is permitted to the transfer processing unit 37. When ACK is not received, the same transmission processing is performed on the bus 3.

  When the thinning process is performed instead of stopping the relay, the thinning process is continued except for the bus to which the bus transmission control unit 39 transmits the CAN frame, and the presence / absence of ACK is similarly determined for the bus transmitting the CAN frame. do it.

  FIG. 15 is an example of a flowchart illustrating a CAN frame relay procedure performed by the gateway ECU 100. The process in FIG. 15 starts when the transfer processing unit 37 receives an ACK from the external device 200.

  The external reception detection unit 38 determines whether a CAN frame has been received from the external device 200 (S210). It may be determined that only one CAN frame has been received, or it may be determined that a CAN frame has been received when a predetermined number or more of CAN frames have been received per unit time.

  When the CAN frame is received (Yes in S210), the transfer processing unit 37 stops relaying the CAN frames of the buses 1 to n or starts thinning out (S220). Thereafter, the bus transmission control unit 39 relays the CAN frame stored in the reception buffer 40 on the DLC side to the transmission buffers 41 of the buses 1 to n. In response to this relay, the CAN frames received from the ECUs of the buses 1 to n are relayed to the external device 200.

  When the external reception detection unit 38 has not received the CAN frame (No in S210), the transfer processing unit 37 relays the CAN frames of the buses 1 to n to the DLC side (S230). If overwriting is detected in this relay process, the thinning process is performed as in the first embodiment.

  As described above, when the gateway ECU 100 according to the present embodiment receives a CAN frame from the external device 200, the external device 200 can transmit data into the vehicle by canceling the relay process.

11 DLC
12 ECU
21, 25-27 CAN controller 31 Transmission buffer 32 Reception buffer 34 Overwrite determination unit 35 Data decimation unit 37 Transfer processing unit 100 Gateway ECU
200 External equipment

Claims (8)

A relay device that relays data from a plurality of nodes mounted on a vehicle to the outside of the vehicle via connection terminals,
Receiving storage means for storing the data received from the node;
Storage means for storing the data to be transmitted to the connection terminal;
Data relay means for relaying the data from the reception storage means to the transmission storage means;
A priority table in which priority information of the data is registered;
Overwrite detection means for detecting that the data in the storage means for reception is overwritten by the data transmitted from the node;
When the overwriting detection unit detects overwriting, the data relay unit relays the data to be relayed, and every time the overwriting detection unit detects overwriting, the data is thinned out in descending order of priority. Data thinning means for increasing the data of interest;
A relay apparatus comprising: The data relay means periodically transmits test data to the connection terminal, and starts relaying the data when the reception response of the test data is obtained.
The relay apparatus according to claim 1. In the priority table, one or more identifiers of the data are registered in one priority information,
The data thinning means increases the thinning frequency of one or more of the data associated with the same priority information every time the overwriting detection means detects overwriting, and one stage when the thinning frequency exceeds a threshold, Initiate decimation of one or more of the data associated with high priority information, or
Each time the overwriting detection means detects overwriting, while continuing the thinning out of the data that had been thinned out before the detection, one step than before the detection, one or more of the one or more associated with higher priority information Start decimation of data,
The relay apparatus according to claim 1 or 2, characterized in that A plurality of buses are connected to the relay device, and one or more nodes are connected to each bus,
In the priority table, one or more identifiers of the bus are registered in one priority information,
The data thinning means increases the thinning frequency of the data received from one or more buses associated with the same priority information every time the overwriting detection means detects overwriting, and the thinning frequency has a threshold value. If exceeded, start decimation of one or more of the data associated with high priority information, or
Each time the overwriting detection means detects overwriting, the data received from the bus that had been thinned out before the detection is continuously thinned out, and is associated with higher priority information by one level than before the detection. Initiating decimation of one or more of the data received from the bus;
The relay apparatus according to claim 1 or 2, characterized in that In the priority table, one or more identifiers of the nodes are registered in one priority information,
A node data conversion table in which identifiers of the data transmitted by the nodes are registered;
The data thinning-out means reads out the identifier of the node associated with the priority information from the priority table when the overwrite detection means detects overwriting, and further identifies the identifier of the node from the node / data conversion table. Determining an identifier of the data associated with
The data thinning means increases the data thinning frequency determined from the priority information every time the overwrite detection means detects overwriting, and corresponds to high priority information when the thinning frequency exceeds a threshold value. Start decimation of one or more of the attached data, or
Each time the overwriting detection means detects overwriting, the data that has been thinned out before the detection is continuously thinned out, and one level of the data determined from higher priority information than before the detection. Start thinning,
The relay apparatus according to claim 1 or 2, characterized in that The data thinning-out means, when the time during which the overwriting detection means does not detect overwriting continues for a predetermined time or longer, excludes the data from thinning objects in order from the data with a higher priority.
The relay device according to claim 1, wherein the relay device is a relay device. In-vehicle transmission storage means for storing the data received from the connection terminal and relayed to the node;
Data reception detecting means for detecting that the data has been received from the connection terminal;
When the data reception detecting means detects that the data has been received, the relay control means for stopping the data relay by the data relay means or reducing the data to be relayed,
The relay apparatus according to claim 1, comprising: Even when the relay control means specifies the node that receives the data stored in the in-vehicle transmission storage means and stops relaying the data by the data relay means, the data relay means Permitting relaying of response data to which the node has received the data stored in the in-vehicle transmission storage means to the connection terminal;
The relay device according to claim 7.

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