JP2007251722A - Communication device, on-vehicle system, data storing method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device for shortening time duration necessary for rewriting processing by reducing the number of data rewriting of a back-up memory. <P>SOLUTION: A control unit 23 for acquiring storing data of a node from the node connected to CAN bus, inserting the storing data and flag information for requiring return of storage data in a predetermined region in the frame data, and transmitting it to another node on CAN bus is provided. The storage data in a memory is not stored in a memory and is transmitted or received with another node, so the number of storage to the memory can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle system in which a plurality of electronic control devices and communication devices (hereinafter referred to as nodes) are connected to a communication bus.

  In vehicles, especially automobiles, computerization is progressing to meet market demands such as fuel saving, safety improvement, and convenience improvement. Along with this, various electronic devices such as control devices, information equipment, and audio equipment have been developed. Control units are being installed.

  These electronic control units (ECUs) are equipped with a backup memory so that the storage data is not lost when the power is turned off. However, when a backup memory is prepared for each electronic control unit, there are problems such as an increase in cost due to the mounting of a plurality of memories, a large leakage current for data storage, and a decrease in battery voltage. Further, a backup memory such as a flash memory has a problem that the number of guaranteed memory rewrites is limited, and data rewrite processing is required when the power is shut off.

  Therefore, Patent Documents 1 to 3 propose a technique for consolidating and storing backup data of each microcomputer in the memory of the main microcomputer when the power is shut down in a system including a plurality of microcomputers.

JP 2004-62406 A JP 2002-297207 A JP-A-6-138888

  However, even if the memory for backup is consolidated into one, the problem that the memory rewrite guarantee frequency is limited and the data rewrite process is required when the power is shut off cannot be solved.

  The present invention has been made in view of the above circumstances, and provides a communication node, an in-vehicle system, a data storage method, and a program that reduce the number of times of data rewriting to a backup memory and shorten the time required for rewriting processing. For the purpose.

In order to achieve such an object, the communication device of the present invention includes an acquisition means for acquiring storage data of the control device from the control device connected to the communication bus, the storage data, and a return of the storage data. Frame generating means for inserting flag information for requesting a predetermined area in a communication frame, transmission means for transmitting the communication frame to another control device connected to a communication bus, and returned from the other control device. Receiving means for receiving the communication frame and taking out the storage data.
As described above, the present invention can reduce the number of times data is stored in the memory by transmitting / receiving data to / from another control device without storing the data for storage in the memory. Further, since it is not necessary to provide a memory for each control device, the cost can be reduced. Furthermore, since it is not necessary to write the storage data to the memory every time the control device is turned off, the time required for the writing process can be shortened.

In the communication device, the storage data and the control device that has transferred the storage data are recognized based on the data storage position in the communication frame, and the frame generation unit is instructed to generate the communication frame including the storage data. It is good to have a control means to do.
Without inserting special information in the communication frame, it is possible to make the communication device recognize the storage data and from which control device.

In the communication device, the control unit may store the storage data in the storage unit when communication with all the control devices connected to the communication bus becomes impossible.
When all the control devices on the communication bus are unable to communicate, the storage data is written, so that the time for the writing process can be shortened.

The communication device may include a switching unit that switches power supply to the control device connected to the communication bus, and the control unit may stop power supply to the control device that has acquired the storage data. .
It is possible to stop the power supply to the control device that has acquired the storage data.

The communication device may include a monitoring unit that monitors a communication state of the communication bus, and the control unit may select a control device that stops power supply according to the communication state of the communication bus.
The power supply to the control device can be stopped according to the communication state of the communication bus.

In the communication apparatus, the communication apparatus may be a communication gateway apparatus that controls transfer of a communication frame between a plurality of communication buses.
In the communication gateway device, the storage data can be managed.

The in-vehicle system of the present invention is an in-vehicle system that includes a control device connected to a plurality of communication buses and a communication gateway device that relays communication frames output from the control devices between the communication buses. The apparatus includes a transmission unit that inserts and transmits storage data in a communication frame before the power is cut off, and the communication gateway apparatus saves the control apparatus from a control apparatus connected to a communication bus. Acquisition means for acquiring data, frame generation means for inserting the storage data and flag information for requesting return of the storage data into a predetermined area in the communication frame, and connecting the communication frame to a communication bus A transmission means for transmitting to the other control apparatus, a reception means for receiving the communication frame returned from the other control apparatus and extracting the storage data; It is configured to have.
The other control device includes: a receiving unit that receives the communication frame; a frame generation unit that extracts the storage data from the communication frame and inserts the data into the communication frame to the communication gateway device; and the communication It is good to have a transmission means which transmits a flame | frame to the said communication gateway apparatus.

  The data storage method of the present invention includes a step of acquiring storage data of a control device from a control device connected to a communication bus, the storage data, and flag information requesting return of the storage data. Inserting the communication frame into a predetermined area; transmitting the communication frame to another control device connected to a communication bus; receiving the communication frame returned from the other control device; And taking out the data for storage.

  The data storage program of the present invention includes a process for acquiring storage data of the control device from the control device connected to the communication bus, the storage data, and flag information for requesting the return of the storage data. A process of inserting the communication frame into a predetermined area; a process of transmitting the communication frame to another control device connected to a communication bus; and receiving the communication frame returned from the other control device; It is good to make a computer perform the process which takes out the data for preservation | save.

  According to the present invention, the number of data rewrites to the backup memory can be reduced, and the time required for the rewrite process can be shortened.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First, a system configuration of an embodiment to which the present invention is applied will be described with reference to FIG.
In this embodiment, a plurality of nodes perform communication according to a CAN (Controller Area Network) protocol, and each node transmits and receives data via a CAN bus. The communication gateway device 1 plays a role of relaying data between these different CAN buses.

  A plurality of nodes are connected on one CAN bus, and the nodes on the same bus are connected by the same power supply line. The communication gateway device 1 also controls the power supply to each power line. In this embodiment, three buses, CAN bus_1, CAN bus_2, and CAN bus_3, are shown as CAN buses, but the number of buses is not limited to three. Further, the number of nodes connected to each CAN bus_1, _2, and _3 does not need to be the same, and can be arbitrarily provided.

  The communication system shown in FIG. 1 is mounted on a vehicle as shown in FIG. FIG. 3 shows a configuration when the communication system is mounted on a vehicle. Examples of nodes when mounted on a vehicle include an engine control ECU, a transmission EUC, a power supply control ECU, an air conditioner ECU, a body ECU, and a security ECU, and control information is communicated between these nodes.

  FIG. 4 shows a detailed configuration of the communication gateway device 1. The communication gateway device 1 includes a routing processing unit 20 and a power supply control unit 30 as shown in FIG. The routing processing unit 20 is a functional unit responsible for data routing, and includes a routing map storage unit 21, a routing unit 22, a control unit 23, and transmission buffers 24_ (1), 24_ provided for each communication channel. (2), 24_ (3), receive buffer 25_ (1), 25_ (2), 25_ (3), CAN controller 26_ (1), 26_ (2), 26_ (3), CAN transceiver 27_ (1), 27_ (2) and 27_ (3).

  The routing map storage unit 21 stores a map for routing and a map in which priorities are set. The priority order map is a map in which the order of nodes that preferentially process data is set when data transfer requests are received from a plurality of nodes. The routing unit 22 sets a CAN bus that outputs the received frame data with reference to these maps.

  The control unit 23 acquires the storage data transferred from the node from which power supply is stopped, and determines a transmission destination node of the storage data. Further, the frame data includes the storage data and flag information for instructing to return the storage data, and transmits the frame data to the destination node. Further, control is performed to extract the storage data from the frame data transmitted from the node and transfer it to the node again.

  The transmission buffers 24_ (1), 24_ (2), and 24_ (3) are provided for each communication channel, and temporarily store the frame data routed by the routing unit 22. The reception buffers 25_ (1), 25_ (2), and 25_ (3) temporarily store the frame data captured by the CAN controllers 26_ (1), 26_ (2), and 26_ (3).

  The CAN controllers 26_ (1), 26_ (2), and 26_ (3) include a part of a microprocessor or a peripheral device, and interface with a CPU (not shown), filtering of frame data, protocol processing, and a CAN transceiver 27. It has functions such as interface. The CAN transceivers 27_ (1), 27_ (2), and 27_ (3) include a bus driver and a receiver, and output data to the CAN bus and input data from the CAN bus.

  Next, the configuration of the power supply control unit 30 will be described. The power supply control unit 30 includes a vehicle state detection unit 31, communication state detection units 32_ (1), 32_ (2), and 32_ (3) provided for each CAN bus, a power supply control determination unit 33, and a switching unit 34. And.

  The vehicle state detection unit 31 receives a switch signal output from an ECU, a sensor, an external connection device, or the like, and detects the state of the vehicle (whether the vehicle is running or stopped) by this signal. . The communication status detection units 32_ (1), 32_ (2), and 32_ (3) are provided for each CAN bus. Is it necessary to supply power to the nodes on the CAN bus by detecting the communication status of the CAN bus? Determine whether or not.

The power supply control determination unit 33 switches between supply and interruption of power to the power supply line according to the detection result of the vehicle state detection unit 31 and the communication state detection unit 32. The power control determination unit 33 switches between supply and stop of power to the power supply line by switching the switch connection of the switching unit 34.
The switching unit 34 switches on and off of the power supply line that supplies power from the power supply unit 10 in accordance with the control of the power supply control determination unit 33.

Next, the configuration of each node connected to the CAN bus will be described with reference to FIG.
The node is an ECU (electronic control unit) that performs communication in accordance with the CAN protocol. Like the communication gateway unit 1, the node is a CAN transceiver 51, a CAN controller 52, a transmission buffer 53, a reception buffer 54, and a control unit 55. And a power supply unit 56.

  When receiving the storage data acquisition request from the communication gateway device 1, the control unit 55 inserts the storage data into a predetermined area of the frame data and transmits it to the communication gateway device 1. Furthermore, in order to stop the operation of the node itself, the storage data is transmitted to the communication gateway device 1 in advance. If the frame data transmitted from the communication gateway apparatus 1 includes flag information indicating a return request for storage data, the control unit 55 extracts the storage data in a predetermined area and extracts the storage data from the communication gateway apparatus 1. Return to

  FIG. 6 shows a configuration of frame data transmitted / received between nodes. The frame configuration is a general configuration, and includes SOF (Start of frame), arbitration field, control field, data field, CRC field, ACK (acknowledgement), and EOF (end of frame) fields.

  In this embodiment, an area for inserting storage data (hereinafter referred to as a storage data insertion area) is provided in the data field. Each node outputs storage data to the communication gateway device 1 before shifting to the power-off state. As shown in FIG. 6, in the frame data, an area where storage data can be inserted is provided for each node. For this reason, the communication gateway device 1 can recognize from which node the data is stored and which node stops the operation. When the communication gateway device 1 acquires the storage data from the node, the communication gateway device 1 performs communication by including this data in the communication data to other nodes. Communication is performed by inserting storage data into a storage data insertion area in the frame data. At this time, the predetermined area in the frame data may include flag information indicating a return request for storage data. The node that has received the frame data inserts the storage data into the frame data and sends it back at the time of data transfer to the communication gateway device 1. Note that the communication gateway device 1 may issue a storage data transfer request to each node on the CAN bus for which power supply is stopped, and receive the storage data transfer from each node.

  The frame data is received by the CAN transceiver 27 (51), and is temporarily stored in the reception buffer 25 (54) after processing such as filtering by the CAN controller 26 (52). When the control unit 23 (55) extracts the storage data from the storage data insertion area for the frame data, the control unit 23 (55) inserts the storage data into the frame data to be transferred to the counterpart node. It is inserted into the area prepared for each node. This frame data is temporarily stored in the transmission buffer 24 (53) and transmitted to the partner node or the communication gateway device 1 via the CAN controller 26 (52) and the CAN transceiver 27 (51).

  Further, when a node in a power-off state returns from this state, it outputs a storage data acquisition request to the communication gateway device 1. Alternatively, the communication gateway device 1 may output the storage data together with the power when the power supply to the node in the power-off state is resumed.

  Further, the communication gateway device 1 includes a memory for storing storage data. When the power supply to all nodes is stopped, the storage gateway device 1 writes the storage data in this memory and shuts off the power.

  As described above, in this embodiment, when the power is shut down, the storage data of each node is not stored in the memory every time, but the storage data is transmitted / received between the communication gateway device 1 and the communicable node, The number of times of saving to the memory can be reduced. Further, since it is not necessary to provide a memory for each node, the apparatus cost can be reduced. Furthermore, since it is not necessary to write the storage data to the memory every time the node is powered off, the time required for the writing process can be shortened.

FIG. 7 shows a flow in which the communication gateway device 1 requests a node on the same power line to transfer storage data, and cuts off the power supply to the power line after the storage data is acquired.
When the communication gateway device 1 detects the state of the vehicle based on the detection signal of the vehicle state detection unit 31 and detects a power supply line that can stop power supply (step S1 / YES), the communication gateway device 1 stores it in each node on the power supply line. A request is made to output data (step S2). Each node that has received the output request sequentially outputs the data for storage to the communication gateway device 1 (step S3). Upon receiving the storage data transfer from the node, the communication gateway device 1 determines whether another CAN bus is busy, and transmits the received frame data including the storage data to a node on the vacant CAN bus. (Step S4). Thereafter, the communication gateway device 1 repeats the transfer of back data data to and from this node. The selection of the communication path for outputting the storage data may be determined according to the availability of the communication path, the frequency of communication, the priority, and the like. When a plurality of nodes are connected on the power supply line from which power supply is stopped, the communication gateway device 1 receives the storage data from the plurality of nodes. In such a case, the communication gateway device 1 may insert storage data of two or more nodes in the same frame data, or perform transmission / reception of frame data with the storage data inserted therein to a plurality of nodes. Also good.

  When the storage data is acquired from all nodes on the power supply line whose power supply is to be stopped (step S5), the communication gateway device 1 stops power supply to the target power supply line (step S6).

In FIG. 8, the communication gateway device 1 does not request the node to transfer storage data, but monitors the data transferred from the node, and stores the storage data from all the nodes on the same power line. When transfer is accepted, a flow for stopping power supply to the corresponding power supply line is shown.
When receiving the transfer of the frame data from the node, the communication gateway device 1 determines whether or not the storage data is included in the frame data (step S10). If it is determined that storage data is inserted in a predetermined area in the frame data (step S10 / YES), the communication gateway device 1 transmits the acquired storage data during communication with a node on another channel ( Step S11). Thereafter, the communication gateway device 1 repeats the transfer of back data data to and from this node.

  Next, the communication gateway device 1 determines whether or not there is a power supply line that has received storage data transferred from all connected nodes (step S12). If it is determined that there is no power supply line that is receiving storage data transfer from all connected nodes (NO in step S12), the process returns to step S10 to continue monitoring the frame data transferred from each node. Do. If it is determined that there is a power line (step S12 / YES), the communication gateway device 1 stops the power supply to the power line (step S13).

  It should be noted that the present invention can also be realized by storing a program for performing control according to the procedure shown in FIG. 7 or FIG. 8 in the control unit 23 and transmitting / receiving storage data by program control.

The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
For example, in the above-described embodiment, a case where communication is performed between nodes connected to the CAN bus has been described as an example. Can do.

  In the above-described embodiment, the case where the storage data is transmitted and received between the communication gateway apparatus 1 and the node has been described as an example. However, the storage data may be transmitted between the nodes. In this case, a main node is set for each CAN bus, and storage data is transmitted and received between the main node and other subnodes.

It is a block diagram which shows a system configuration. It is a figure which shows the case where the system shown in FIG. 1 is mounted in a vehicle. It is a figure which shows the structural example at the time of mounting the system shown in FIG. 1 in a vehicle. It is a block diagram which shows the structure of a communication gateway apparatus. It is a block diagram which shows the structure of a node. It is a figure which shows the structure of frame data. It is a flowchart which shows the process sequence of a communication gateway apparatus. It is a flowchart which shows the process sequence of a communication gateway apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication gateway apparatus 10 Power supply part 20 Routing process part 21 Routing map storage part 22 Routing part 23 Control part 24 Transmission buffer 25 Reception buffer 26 CAN controller 27 CAN transceiver 30 Power supply control part 31 Vehicle state detection part 32 Communication state detection part 33 Power supply Control judgment unit 34 switching unit

Claims (10)

Acquisition means for acquiring storage data of the control device from the control device connected to the communication bus;
Frame generating means for inserting the storage data and flag information for requesting the return of the storage data into a predetermined area in a communication frame;
Transmitting means for transmitting the communication frame to another control device connected to a communication bus;
Receiving means for receiving a communication frame returned from the other control device and extracting the storage data;
A communication apparatus comprising:   It has control means for recognizing storage data and the control device that transferred the storage data according to the data storage position in the communication frame, and instructing the frame generation means to generate a communication frame including the storage data. The communication apparatus according to claim 1.   3. The communication device according to claim 2, wherein the control unit stores the storage data in a storage unit when communication with all control devices connected to the communication bus becomes impossible. Switching means for switching power supply to the control device connected to the communication bus;
The communication apparatus according to claim 2, wherein the control unit stops power supply to the control apparatus that has acquired the storage data. Monitoring means for monitoring the communication state of the communication bus;
4. The communication apparatus according to claim 2, wherein the control unit selects a control apparatus that stops power supply according to a communication state of the communication bus.   The communication device according to claim 1, wherein the communication device is a communication gateway device that controls transfer of a communication frame between a plurality of communication buses. An in-vehicle system equipped with a control device connected to a plurality of communication buses and a communication gateway device that relays communication frames output from the control devices between the communication buses,
The control device has transmission means for inserting and transmitting storage data in a communication frame before the power is cut off,
The communication gateway device, from a control device connected to a communication bus, acquisition means for acquiring data for storage of the control device;
Frame generating means for inserting the storage data and flag information for requesting the return of the storage data into a predetermined area in a communication frame;
Transmitting means for transmitting the communication frame to another control device connected to a communication bus;
Receiving means for receiving the communication frame returned from the other control device and extracting the storage data;
An in-vehicle system characterized by comprising: The other control device includes a receiving unit that receives the communication frame;
Frame generating means for taking out the storage data from the communication frame and inserting it into the communication frame to the communication gateway device;
Transmitting means for transmitting the communication frame to the communication gateway device;
The vehicle-mounted system according to claim 7, further comprising: Obtaining storage data of the control device from the control device connected to the communication bus;
Inserting the storage data and flag information requesting return of the storage data into a predetermined area in a communication frame;
Transmitting the communication frame to another control device connected to a communication bus;
Receiving the communication frame returned from the other control device, and extracting the storage data;
A data storage method characterized by comprising: A process of acquiring data for storage of the control device from the control device connected to the communication bus;
Processing for inserting the storage data and flag information for requesting return of the storage data into a predetermined area in a communication frame;
Processing for transmitting the communication frame to another control device connected to a communication bus;
Receiving the communication frame returned from the other control device, and extracting the storage data;
A data storage program for causing a computer to execute.

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