JP2007181061A - Electronic controller, can system and method for diagnosing failure of can system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform failure judgment according to operation environment of an electronic controller for diagnosis to exactly perform failure diagnosis of the electronic controller. <P>SOLUTION: In a CAN system constituted of ECUs 1-3 and a CAN bus line 4, an ECU 1 receives and stores operation characteristics data transmitted by an ECU 2. The ECU 1 determines permission/prohibition of diagnosis and adoption or rejection of a control parameter from the ECU 2 based on the stored operation characteristics data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic control device, a CAN (Controller Area Network) system, and a failure diagnosis method for a CAN system, and in particular, a vehicle system adopting CAN as a control information transmission means between on-vehicle electronic control devices such as an engine control device. The present invention relates to an electronic control device, a CAN system, and a failure diagnosis method for a CAN system.

  In an automobile or the like, a plurality of electronic control devices such as an engine electronic control device, a transmission electronic control device, a steering electronic control device, etc. Some are connected to a line and perform mutual communication between in-vehicle electronic control devices using a controller area network (hereinafter simply referred to as CAN) protocol that is a typical standard network protocol.

In such a CAN system (control system), a reception interval of data transmitted from a plurality of electronic control devices connected to the CAN bus line and forming a communication node is monitored, and a faulty electronic control device is specified. A technique is known (for example, Patent Document 1).
JP 2003-143164 A

  However, in a CAN system that performs such communication failure detection, failure determination is simply performed based on whether or not there is reception from an electronic control device connected to the CAN bus line. If the diagnosis is executed in a situation that is not in an environment that operates correctly, for example, in a situation where the battery voltage or the start-up time is not in a normal state, there is a possibility that a normal electronic control device is erroneously determined as a failure.

  In order to avoid such a situation, it is also possible to store and determine the operating environment range value to be diagnosed in the electronic control device that executes the diagnosis. However, since the operating environment range is different for each electronic control device, the operating environment range cannot be determined uniformly, and the electronic control device that executes diagnosis determines the operating environment range value of the diagnosis target electronic control device for each electronic control device. Need to be memorized individually.

  Even if the operating environment range value of the diagnosis target electronic control device is stored in the electronic control device that executes the diagnosis, if the operation environment range of the electronic control device that is the diagnosis target is changed, the electronic control device that executes the diagnosis It is also necessary to change the operating environment range value stored in. For this reason, the operating environment range value stored in the electronic control unit that executes diagnosis can only be set with a considerable margin, and the area in which failure determination can be performed is limited. For this reason, it is difficult for the conventional control system to accurately diagnose the failure of the electronic control device.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to perform failure determination in accordance with the operating environment of the electronic control device to be diagnosed and accurately diagnose failure of the electronic control device. It is an object to provide an electronic control device, a CAN system, and a failure diagnosis method thereof that can be performed.

  To achieve the above object, an electronic control device according to the present invention is an electronic control device connected to a CAN bus line and having means for acquiring data of the CAN bus line, and is connected to the same CAN bus line. It receives operation characteristic data from other electronic control units and stores the received operation characteristic data in its own memory.

  In the electronic control device according to the present invention, preferably, the memory for storing the received operation characteristic data is constituted by a memory for holding a stored value even when the power is stopped.

  The electronic control device according to the present invention further comprises means for monitoring the communication status of the other electronic control device connected to the same CAN bus line and diagnosing the abnormality, and using the operation characteristic data stored in the memory as a condition. Allow / prohibit abnormality diagnosis.

  The electronic control device according to the present invention preferably determines whether or not the received data from the other electronic control device connected to the same CAN bus line is accepted as the operating characteristic data condition stored in the memory.

  The electronic control device according to the present invention preferably uses temporary operation characteristic data set in advance until the operation characteristic data is received and the operation characteristic data is stored in the memory.

  To achieve the above object, an electronic control device according to the present invention is an electronic control device connected to a CAN bus line and having means for sending data to the CAN bus line. Data is sent to the CAN bus line.

  In order to achieve the above object, a CAN system according to the present invention includes a plurality of electronic control units having the same CAN having means for sending data to the CAN bus line and means for obtaining data on the CAN bus line. In the CAN system connected to the bus line, the electronic control device to be diagnosed among the electronic control devices sends operating characteristic data indicating its operating environment to the CAN bus line, and Among them, the electronic control unit that executes the diagnosis receives the operation characteristic data sent to the CAN bus line from the electronic control unit to be diagnosed, stores the received operation characteristic data in its own memory, and stores it in the memory Based on the obtained operation characteristic data, the permission / prohibition of the diagnosis is determined, and the failure of the electronic control device to be diagnosed is detected.

  In order to achieve the above object, according to the failure diagnosis method of a CAN system according to the present invention, a plurality of electronic control units for transmitting data to the CAN bus line and acquiring the data of the CAN bus line have the same CAN bus line. A failure diagnosis method for a CAN system connected to the electronic control device, wherein the electronic control device to be diagnosed among the electronic control devices sends operating characteristic data indicating its own operating environment to the CAN bus line, and An electronic control unit that executes diagnosis among the devices receives the operation characteristic data sent to the CAN bus line from the electronic control unit to be diagnosed, stores the received operation characteristic data in its own memory, and the memory Based on the operation characteristic data stored in the above, the permission / prohibition of the diagnosis is determined, and the failure of the electronic control device to be diagnosed is detected.

  According to the present invention, an electronic control device that executes diagnosis receives operating environment parameters (operation characteristic data) of another electronic control device (electronic control device to be diagnosed) connected to the same CAN bus line, Since the received operation characteristic data is stored in its own memory, in the failure determination of the electronic control device that is connected to the CAN bus line and transmits the data, the diagnosis is performed in accordance with the operating environment of the electronic control device to be diagnosed Can do. Even if the operating environment of the electronic control unit to be diagnosed is changed, it is not necessary to change the electronic control unit that executes the diagnosis. Is possible.

  As a result, it is possible to make a failure determination in accordance with the operating environment of the electronic control device to be diagnosed and accurately perform a failure diagnosis of the electronic control device.

  An embodiment of an electronic control device and a CAN system according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the CAN system of this embodiment includes an engine control ECU 1 (hereinafter referred to as ECU 1) and an AT control ECU 2 (hereinafter referred to as ECU 2) as an electronic control device (hereinafter referred to as ECU) mounted on a vehicle. ) And the meter control ECU 3 (hereinafter, ECU 3) are connected to a common CAN bus line 4 as communication notes. Each of the ECUs 1 to 3 enables transmission / reception of information through a CAN bus line 4 and a communication method defined in the CAN communication specification.

  Each of the ECUs 1 to 3 is of a computer type and includes a CPU 10, a CAN controller 11, a transceiver 12, a ROM 13, and a RAM 14, as shown in FIG.

  The transceiver 12 is connected to the CAN bus line 4 and the CAN controller 11 and has a role of converting a differential signal of the CAN bus line 4 into a digital signal composed of binary values of 0V and 5V that can be recognized by the CAN controller 11.

  The CAN controller 11 is connected to the CPU 10 and expands the data instructed from the CPU 10 into a data format defined in the CAN communication specification, and then sends the data to the CAN bus line 4 via the transceiver 12 and transmits it to another ECU. To do. Further, the CAN controller 11 selects and acquires necessary data from data sent to the CAN bus line 4 by other ECUs, and notifies the CPU 10 of the selected data. As a result, the CAN controller 11 serves as means for sending data to the CAN bus line 4 and means for obtaining data on the CAN bus line 14.

The ROM 13 is used for storing programs and control data.
The CPU 10 performs calculation of parameters necessary for control according to a program and control data stored in the ROM 13, and controls the CAN controller 11 to transmit and receive parameters.

  The RAM 14 is used for storing calculation results of the CPU 10 and information acquired from the CAN controller 11.

  Although the ECUs 1 to 3 in the present embodiment are described as having the same configuration, for example, the ECU 1 does not necessarily include the ECU 2 and the ECU 3 such as using an IC in which the CPU 10, the CAN controller 11, the ROM 13 and the RAM 14 are in one package. It is not necessary to have the same configuration as

  FIG. 3 shows an example of operation characteristics of the ECUs 1 to 3. FIG. 3A shows the operating voltage, and FIG. 3B shows the CAN communication startable time after power-on as an example.

  FIG. 3A shows that the ECU 1 can operate in the range of 6V to 18V, the ECU 2 can operate in the range of 8V to 16V, and the ECU 3 can operate in the range of 5V to 16V. FIG. 3B shows a time period during which CAN communication can be performed after power-on. ECM1 is 200 ms, ECM2 is 250 ms, and ECM3 is 150 ms.

  As described above, it is assumed that the operation characteristics of the ECU connected to the CAN bus line 4 are different, and information obtained from the ECU is also limited within the range of the operation characteristics.

The exchange of the operation characteristic data of the ECU will be described with reference to FIG.
The ECU 2 to be diagnosed stores the operable voltage lower limit data 213a, operable voltage upper limit data 213b, and CAN communication startable time data 213c of the ECU 2 as its operating environment parameters (operation characteristic data) in the ROM 213. Yes. The ECU 2 sends these operation characteristic data to the CAN bus line 4 via the CPU 210, the CAN controller 211, and the transceiver 212.

  The ECU 1 that executes the diagnosis acquires operating characteristic data from the CAN bus line 4 via the transceiver 112, the CAN controller 111, and the CPU 110, and operates in an operable voltage lower limit value area 114a and an operable voltage provided in the RAM 114 in the ECU 1. Operable voltage lower limit data 213a, operable voltage upper limit data 213b, and CAN communication startable time data 213c from the ECU 2 are stored in the upper limit value area 114b and the CAN communication startable time value area 114c. Thereby, ECU1 which performs a diagnosis can recognize the operation characteristic data of ECU2 used as a diagnostic object.

  Note that the RAM 114 that stores the operation characteristic data is preferably a memory that is backed up so that the stored value can be held even when the power of the ECU 1 is stopped, or a nonvolatile memory that can be electrically rewritten, such as an EEPROM. This is because the operation characteristic data must be received from other ECUs by CAN communication, and until the operation characteristic data is received, the data received and stored until the previous time is held. This is so that the ECU 1 can be used immediately after the power is turned on.

  The ECU 1 that executes the diagnosis stores the temporary operable voltage lower limit data 113a, the temporary operable voltage upper limit data 113b, and the temporary CAN communication startable time data 113c of the ECU 2 in the ROM 113.

  Next, a method for using the received / stored operation characteristic data will be described with reference to the flowchart shown in FIG. Here, in FIG. 4, ECU 1 diagnoses ECU 2 that has sent operating characteristic data (operable voltage lower limit data 213 a, operable voltage upper limit data 213 b, CAN communication start possible time data 213 c), and control data received from ECU 2. This will be described with reference to an example of determining whether to accept or reject. Since the present invention is not an invention related to a diagnostic method, a detailed description of the diagnostic method is omitted.

  As described above, the operation characteristic data sent out by the ECU 2 is stored in the RAM 114 in the ECU 1. When the power is turned on, the ECU 1 executes the processing of the flowchart shown in FIG. 5 at a predetermined cycle (for example, every 10 ms).

  In this process, first, the timer Ton is counted to measure time (step S101). This time measurement value corresponds to the time after the power is turned on.

  Next, the measured time (timer Ton) is compared with the CAN communication startable time value written in the CAN communication startable time value area 114c (step S102). If it is determined that the CAN communication startable time / not yet elapsed, the diagnosis process (step S104) is skipped. That is, the diagnosis process is prohibited and the diagnosis process is not executed.

  If it is determined that the CAN communication startable time has elapsed, then the battery voltage recognized by the ECU 1 is compared with the operable voltage lower limit value written in the operable voltage lower limit value area 114a. . If it is determined that the battery voltage is lower than the operable voltage lower limit value, the diagnostic process (step S104) is skipped. That is, the diagnosis process is prohibited and the diagnosis process is not executed.

  When it is determined that the battery voltage is higher than the operable voltage lower limit value, the diagnosis process is permitted, and the diagnosis process for monitoring the CAN reception data of the ECU 2 is executed (step S104).

  Thus, compared with the parameters generated in the ECU 1, diagnosis is prohibited before the ECU 2 can start CAN communication or when the current battery voltage is lower than the operable voltage of the ECU 2. In the vehicle, by operating the key switch, a voltage using the battery as a power source is simultaneously applied to the ECU 1 and the ECU 2. Therefore, the time measured by the ECU 1 can be compared with the CAN communication startable time value of the ECU 2. The battery voltage detected by the ECU 1 can be compared with the operable voltage value of the ECU 2.

  Next, the battery voltage is compared with the operable voltage lower limit value written in the operable lower limit value region 114a and the operable voltage upper limit value written in the operable upper limit value region 114b, and the battery voltage is within a predetermined range. (Step S105). If the battery voltage is not within the predetermined range, the CAN data adoption process (step S106) is skipped. When it is determined that the battery voltage is within the predetermined range, a CAN data adoption process that employs the control data received from the ECU 2 is performed (step S106).

  Thereby, in the area where the operation of the ECU 2 cannot be guaranteed, the control data received from the ECU 2 is discarded, and the malfunction of the process executed based on the control data of the ECU 2 is prevented.

  The CAN system of the present embodiment is characterized in that, in failure diagnosis, the operation characteristic data of the ECU 2 to be diagnosed is a value received and stored from the CAN by the ECU 1 that executes the diagnosis.

  Here, for example, even when the ECU 2 is changed due to a model change or the like and the operation characteristic data is changed, the ECU 1 can make a determination by using new operation characteristic data transmitted from the changed ECU 2. The ECU 2 can be model changed without affecting the ECU 1.

  As described above, in the CAN system of the present embodiment, the operating environment parameters (characteristic data; for example, the minimum operating voltage, the startup time from power-on, are connected to the ECU connected to the CAN bus line 4 via the CAN bus line 4. When the operating environment parameters are received from other ECUs, they are stored in the memory, so that the ECU executing the diagnosis can grasp the operating environment of the ECU to be diagnosed. As a result, for example, when performing diagnosis (failure detection) by monitoring data sent to the CAN bus line 4, it is possible to determine whether or not to permit diagnosis based on the operating environment parameters stored in the memory. It is possible to prevent erroneous determination due to. Further, even when the ECU is changed for some reason and the operating environment parameter is changed, the new operating environment parameter corresponding to the changed ECU can be known, so that the influence on other ECUs can be suppressed.

  If the vehicle is broken, for example, if the CAN bus line 4 is disconnected, the operating characteristic data cannot be received. On the other hand, provisional characteristic data (provisional operable voltage lower limit data 113a, provisional operable voltage upper limit data 113b, provisional CAN communication startable time data 113c having sufficient allowance for the operation characteristic data of the ECU 2 is provided. ) Is previously stored in the ROM 113 of the ECU 1, and the initial process of the ECU 1 shown in FIG. 6 is executed.

  In the initial process, first, it is determined whether or not there is a reception history of operation characteristic data from the ECU 2 (step S110). If it is determined that there is no reception history, the temporary characteristic data (temporary operable voltage lower limit data 113a, temporary operable voltage upper limit data 113b, temporary CAN communication startable time data 113c) stored in the ROM 113 are stored in the RAM 114, respectively. Copy to the operable voltage lower limit value area 114a, the operable voltage upper limit value area 114b, and the CAN communication startable time value area 114c (step S111).

  Thus, the determinations in steps S102, S103, and S105 shown in FIG. 5 may be executed using the temporary operating characteristic data. Thereafter, when it becomes possible to receive the operation characteristic data from the ECU 2, if each value is overwritten in each area of the RAM 114 in the received data adoption process (step S106), the determination based on the operation characteristic data of the ECU 2 is performed. It can be done continuously.

  In addition, although ECU1 and ECU2 were demonstrated to the example among ECU connected to the CAN bus line 4, it can implement | achieve similarly also about other ECUs, for example, combination like ECU1 and ECU3.

1 is a network diagram showing an embodiment of a CAN system including an electronic control device according to the present invention. The block diagram which shows one Embodiment of the electronic control apparatus by this invention. (A) is a graph which shows the example of operable voltage of each ECU in a CAN system, (b) is a graph which similarly shows the example of CAN communication start possible time. The block diagram which shows the detail of one Embodiment of the electronic control apparatus and CAN system by this invention. The flowchart which shows operation | movement of one Embodiment of the electronic control apparatus by this invention. The flowchart which shows the initial process of one Embodiment of the electronic control apparatus by this invention.

Explanation of symbols

1-3 Electronic control unit (ECU)
4 CAN bus line 10 CPU
11 CAN controller 12 Transceiver 13 ROM
14 RAM
110 CPU built in ECU1
111 CAN controller 112 built in ECU1 112 transceiver 113 built in ECU1 ROM built in ECU1
114 RAM built in ECU1
210 CPU built in ECU2
211 CAN controller 212 built in ECU 2 Transceiver 213 built in ECU 2 ROM built in ECU 2
214 RAM built in ECU 2

Claims (8)

An electronic control device connected to a CAN (Controller Area Network) bus line and having means for acquiring data of the CAN bus line,
An electronic control device that receives operation characteristic data from another electronic control device connected to the same CAN bus line and stores the received operation characteristic data in its own memory.   The electronic control device according to claim 1, wherein the memory that stores the received operation characteristic data is configured by a memory that retains a stored value even when the power is stopped.   A means for monitoring the communication status of the other electronic control devices connected to the same CAN bus line and diagnosing the abnormality is provided, and abnormality diagnosis is permitted / prohibited based on the operation characteristic data stored in the memory. The electronic control device according to claim 1 or 2.   4. The acceptance / rejection of received data from the other electronic control unit connected to the same CAN bus line is determined based on the operation characteristic data stored in the memory. The electronic control device according to item.   The temporary operating characteristic data set in advance is used until the operating characteristic data is received and stored in the memory. The electronic control device described. An electronic control device having means for sending data to the CAN bus line, connected to a CAN (Controller Area Network) bus line,
An electronic control device, characterized in that operating characteristic data indicating its own operating environment is sent to the CAN bus line. A CAN system in which a plurality of electronic control units having means for sending data to a CAN (Controller Area Network) bus line and means for obtaining data on the CAN bus line are connected to the same CAN bus line,
The electronic control device to be diagnosed among the electronic control devices sends operating characteristic data indicating its own operating environment to the CAN bus line,
The electronic control unit that executes diagnosis among the electronic control units receives the operation characteristic data sent from the electronic control unit to be diagnosed to the CAN bus line, and stores the received operation characteristic data in its own memory. A CAN system that judges permission / prohibition of diagnosis based on operation characteristic data stored in the memory, and detects a failure of an electronic control device to be diagnosed. A failure diagnosis method for a CAN system in which a plurality of electronic control units that transmit data to a CAN (Controller Area Network) bus line and acquire data on the CAN bus line are connected to the same CAN bus line,
The electronic control device to be diagnosed among the electronic control devices sends operating characteristic data indicating its own operating environment to the CAN bus line,
The electronic control unit that executes diagnosis among the electronic control units receives the operation characteristic data sent from the electronic control unit to be diagnosed to the CAN bus line, and stores the received operation characteristic data in its own memory. A failure diagnosis method for a CAN system, wherein permission / prohibition of diagnosis is determined based on operation characteristic data stored in the memory, and failure detection of an electronic control device to be diagnosed is performed.

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