JP6505482B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control unit mounted on a vehicle.

  For example, a network system such as CAN (Controller Area Network) is adopted in an electronic control unit mounted on a car (see, for example, Patent Document 1).

  By the way, inspection of the electronic control device (shipment inspection as an example) is performed by, for example, connecting the electronic control device and the inspection device by a communication line and using a communication protocol for control such as CAN. On the electronic control device side, it is necessary to avoid transitioning to processing other than the inspection before the end of the inspection during the inspection mode in which the inspection is performed. Therefore, in the electronic control device, for example, the inspection mode is held by alternately receiving arbitrary data (bit value) and its inverted value from the inspection device side.

JP, 2014-187445, A

  However, for example, if the transmission cycle of data transmitted from the inspection apparatus fluctuates due to a load on a central processing unit (CPU) of the inspection apparatus, acquisition of received data at a timing that should be originally received (dropping) ), And the inspection mode is canceled at an unexpected timing, as a result, it becomes easy for the misdiagnosis of the inspection to occur. Therefore, it becomes difficult to perform an inspection reliably. In the above example, the inspection mode has been described and explained, but the present invention is not limited to the inspection mode, and the suppression of the release of the mode at an unexpected timing under a state where the mode to execute predetermined processing should be maintained desirable.

  Therefore, in view of the problems of the prior art, an object of the present invention is to provide a technique for suppressing the release of the mode at an unexpected timing.

According to the present invention, the inspection which executes the processing of the inspection according to the command signal instructing the processing of the inspection regarding the vehicle, including the first signal and the second signal alternately outputted in the predetermined transmission cycle The electronic control unit for an automobile continues to maintain the inspection mode until the end of the inspection as long as the mode is switched to and the first signal and the second signal are alternately acquired without leakage , and at least during the execution of the inspection mode The command signal is obtained even if the transmission cycle fluctuates by sampling the first signal and the second signal at a cycle shorter than a time interval in which the first signal and the second signal alternately change. Control the acquisition leak of

  According to the present invention, it is possible to suppress the release of the mode at an unexpected timing.

It is a figure showing an example of the inspection system of the electronic control unit carried in vehicles, such as a car. It is a figure which shows the hardware structural example of ECU shown in FIG. It is a figure which shows the hardware structural example of the test | inspection apparatus shown in FIG. It is a figure explaining an example of the timing chart (comparative example) at the time of normal. It is a figure explaining an example of a timing chart (comparative example) when fluctuation occurs in a transmission cycle. It is a flowchart which shows an example of operation | movement of the inspection method in this embodiment. It is a flowchart which shows an example of operation | movement of the inspection method in this embodiment. It is a figure explaining an example of the timing chart at the time of normality in this embodiment. It is a figure explaining an example of a timing chart in the case of performing control processing which controls an acquisition omission of a test instruction signal in this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the following embodiments, an inspection system is described as an example, but the present invention is not limited thereto.
[Example of inspection system configuration]
FIG. 1 is a diagram showing an example of an inspection system of an electronic control unit (ECU: Electronic Control Unit) mounted on a vehicle such as a car.

  The ECU 1 to be inspected is detachably connected to the inspection device 3 via the network cable 2. This facilitates the inspection of the ECU 1. For example, a communication protocol of CAN can be used between the ECU 1 and the inspection device 3. The communication protocol is not limited to CAN, and may be another communication protocol such as FlexRay (registered trademark).

  The ECU 1 is an electronic device that controls various devices mounted on a vehicle such as a car, for example, a fuel injection valve, a transmission, an electric brake system, an ABS (Antilock Brake System), a variable valve timing mechanism, and a brushless motor. And a processor for executing arithmetic processing and the like.

  FIG. 2 is a diagram showing an example of a hardware configuration of the ECU 1 shown in FIG. The ECU 1 includes a processor 11, a communication circuit 12, a ROM (Read Only Memory) 13, a RAM (Random Access Memory) 14, and a bus 15. The processor 11, the communication circuit 12, the ROM 13 and the RAM 14 are connected to one another via a bus 15.

  The processor 11 is, for example, a CPU responsible for central processing of the system, and performs overall control of the ECU 1. The communication circuit 12 provides a communication interface for connecting to a network. The communication circuit 12 includes a bus controller (CAN controller) that implements a CAN communication protocol. Although CAN is employed in this embodiment, the details of the CAN communication protocol are known and will not be described. Here, the communication circuit 12 includes a connector (not shown) for detachably connecting the network cable 2.

  The ROM 13 is, for example, a non-volatile semiconductor memory such as a flash ROM or the like in which data is held even when the power supply is shut off. The RAM 14 is, for example, a memory serving as a temporary work area for data used for arithmetic processing and the like, and is a volatile memory in which stored contents disappear when power supply is interrupted. The RAM 14 may be, for example, a dynamic RAM or a static RAM. The bus 15 can be used for data transfer of CAN communication and the like.

  Further, the ECU 1 realizes various functions by cooperation of hardware such as the processor 11, the ROM 13 and the RAM 14 and software such as a control program stored in the ROM 13. The control program includes an inspection program that performs processing such as the inspection method of the present embodiment. Therefore, the processor 11 implements the processing of the inspection method of the present embodiment by executing the inspection program.

  FIG. 3 is a diagram showing an example of the hardware configuration of the inspection apparatus 3 shown in FIG. The inspection device 3 is configured by an electronic device such as a personal computer that instructs the ECU 1 to perform an inspection process on the vehicle by receiving a command input from the worker, and causes the ECU 1 to execute the inspection. Specifically, as shown in FIG. 3, the inspection apparatus 3 includes a processor 31 such as a CPU, a communication circuit 32 for connecting to a network such as a CAN, a storage 33 such as a hard disk drive, and a worker. It comprises an input / output device 34 serving as an interface and a bus 35.

  The processor 31, the communication circuit 32, the storage 33, and the input / output device 34 are connected to one another via a bus 35. Here, the communication circuit 32 includes, similarly to the communication circuit 12, a bus controller (CAN controller) and a connector (not shown) for detachably connecting the network cable 2. The input / output device 34 also includes a display such as a liquid crystal display (LCD), a keyboard, and a pointing device such as a mouse. The storage 33 may be, for example, a network attached storage (NAS) connected to a network, a storage of a server, or the like.

[Comparison with conventional example]
Here, in order to understand the technology disclosed in the present invention in more detail, a conventional example is applied to the present embodiment, and an example of inspection of the ECU 1 will be briefly described using a timing chart. This inspection is, for example, an inspection (shipment inspection mode) related to a vehicle performed before shipment to the factory, and specifically, an inspection related to operation check inside the ECU 1 for operating various devices mounted on the vehicle normally. It is.

  FIG. 4 is a diagram for explaining an example of a timing chart (comparative example) at the normal time. In FIG. 4, in the inspection of the ECU 1, the state in which the inspection command signal is output (transmitted) in time series at a predetermined transmission cycle (10 milliseconds [ms]) initialized from the inspection device 3 is illustrated. There is. In FIG. 4, the transmission cycle, the flow of data, the sampling cycle, the received data stored, and the state of the ECU 1 are shown by a timing chart. Here, the transmission cycle is an example of a time interval at which a test command signal changes, and the test command signal is an example of a command signal, and for example, a first signal consisting of a predetermined bit value of n-ary number and the bit This is a second signal consisting of a bit value obtained by inverting the value.

  Specifically, in the present embodiment, as an example, a bit value of AAh in hexadecimal (binary: 10101010) and an inverted value 55h of AAh (binary: 01010101) are used. The inspection apparatus 3 alternately outputs the first signal (AAh) and the second signal (55h) in a transmission cycle (10 milliseconds) as an example of a command signal that changes according to a predetermined rule. Although the inspection command signal is communication data in accordance with the data format of the CAN communication protocol, it is denoted by AAh, 55h to make the description easy to understand. Further, the values of the first signal and the second signal are not limited to AAh and 55h, respectively, and may be different from each other. Furthermore, in the present embodiment, it is possible to apply as an inspection command signal if it follows a predetermined rule, such as an incrementing or decrementing number. The inspection command signal may be a regular value determined between the transmitting and receiving sides. Specifically, the inspection command signal may be, for example, a data string that repeats as 00h → 01h → 02h → 03h → 00h →.

  Further, in FIG. 4, the flow of data, the sampling cycle column is synchronized with the transmission cycle as an example via the network cable 2 on the ECU 1 side, and the inspection command signal is acquired at a sampling cycle (reception cycle) of 10 milliseconds. It illustrates the state of going on. Also, the column of the received data stored indicates data (a first signal (AAh) or a command signal of the second signal (55h)) stored in the RAM 14 at each sampling cycle. Furthermore, FIG. 4 shows the state of the ECU 1 (during standby for the shipping inspection mode, during shipping inspection mode).

  In the shipping inspection, the ECU 1 acquires (receives) the inspection command signal output from the inspection device 3 and further acquires the inspection command signal for the prescribed number of times set in advance, thereby checking the shipment from standby in the shipping inspection mode. Transition to mode and start inspection. And ECU1 performs an inspection, while acquiring an inspection command signal. In the ECU 1, the acquired inspection command signal is sequentially stored in the RAM 14, and the processor 11 switches from standby in the shipment inspection mode to the shipment inspection mode according to the data string of the inspection instruction signal, or shipment inspection from the shipment inspection mode. Switch during mode standby.

  In FIG. 4, the timing of the inspection command signals (AAh, 55h) alternately output from the inspection device 3 to the ECU 1 in a transmission cycle of 10 milliseconds, for example, is indicated by a vertically downward arrow. The width of each block shown in the data flow column indicates the interval of the transmission cycle, and the inspection command signal output from the inspection device 3 flows to the communication circuit 12 of the ECU 1 through the communication data bus of the network cable 2 The process is shown schematically.

  Further, each rectangle in the column of the sampling period schematically shows the reception processing at a sampling period of every 10 milliseconds in the ECU 1, and the vertically upward arrow pointing to each block of the data flow from each rectangle is that time It shows that the inspection command signal (one of 55h and AAh) is received at the timing. The width of each block shown in the column of the received data stored indicates the value of the received data stored in the RAM 14 in a time zone determined according to the transmission cycle. In FIG. 4, arrows pointing to each block of received data stored from the respective rectangles indicate timings at which the ECU 1 stores 55 h or AA h as received data in the RAM 14.

  Specifically, the processor 11 first determines whether the shipping inspection mode is in standby or in the shipping inspection mode, and when in the shipping inspection mode, inspection command signals of 55h and AAh in chronological order are determined. It is determined whether is alternately acquired. Furthermore, the processor 11 determines whether or not the number of acquisitions of the inspection command signal has reached a predetermined number set in advance. Subsequently, when the processor 11 reaches the specified number of times, the processor 11 transitions from waiting for the shipping inspection mode to the shipping inspection mode. Thereby, the processor 11 is in the shipping inspection mode, that is, while alternately acquiring the inspection command signals of 55h and AAh in time series, for example, inspection items of the ECU 1 predetermined by the self-diagnosis program or the like. , To check if it is normal or not.

  Here, the processor 11 can not alternately acquire the inspection command signals of 55h and AAh, and when the number of times of acquisition can not reach the specified number, the shipment inspection mode should normally be continued, and the shipment inspection It misjudges as the end of mode and makes transition while waiting for shipment inspection mode. In other words, the processor 11 continues to maintain the shipping inspection mode until the end of the inspection as long as 55h and AAh are alternately and normally acquired without leakage as inspection instruction signals even after transition to the shipment inspection mode.

  FIG. 5 is a diagram for explaining an example of a timing chart (comparative example) when fluctuations occur in the transmission cycle. When the transmission cycle fluctuates, a deviation occurs between the sampling cycle. Even in the shipping inspection mode, it is necessary to obtain an inspection command signal normally without leakage. However, when the fluctuation of the transmission cycle occurs on the inspection device 3 side, the above-mentioned deviation occurs, and as a result, for example, an acquisition leak occurs in which the inspection command signal can not be acquired alternately.

  Note that the acquisition omission is not limited to the case where the inspection command signal can not be acquired alternately, such as a lack of received data, but in the present embodiment, the inspection command signal can not be acquired alternately to make the explanation easy to understand. Do. Therefore, it goes without saying that the present embodiment is also applicable to the loss of received data.

  In FIG. 5, the block width of the data flow is different between AAh and 55h because the fluctuation of the transmission cycle is schematically shown. The processor 11 acquires 55h at time t1 but does not acquire AAh at time t2 and stores it in the RAM 14 although 55h is acquired at time t1 when acquiring data in sampling cycles every 10 milliseconds.

  Subsequently, the processor 11 obtains 55h at time t3 of the next sampling cycle. However, when the processor 11 already stores the same value (55h) in the RAM 14 at the previous time t2 for the convenience of processing, the data storage processing is not performed, and the reception state of the data continues. To be. That is, since the processor 11 can not alternately acquire the values 55h and AAh, it indicates that an acquisition leakage has occurred. Note that the dotted upward arrow from the rectangle in the column of the sampling period shown in FIG. 5 indicates that the processor 11 reads (acquires) data but does not execute writing (storage) to the RAM 14 .

  Here, when the number of acquisition leaks of the inspection command signal reaches a specified number due to the fluctuation of the transmission cycle, the processor 11 abnormally ends the shipment inspection mode and makes transition in the shipment inspection mode waiting. As a result, as described above, the shipping inspection mode at an unexpected timing is canceled, and a false diagnosis of the inspection tends to occur, making it difficult to reliably execute the inspection.

Therefore, in the following embodiment, a technique for suppressing the release of the shipping inspection mode at an unexpected timing will be described.
[Operation processing of this embodiment]

  FIG. 6 is a flowchart showing an example of the operation of the inspection method in the present embodiment. This flowchart exemplifies processing up to transition to the shipping inspection mode, and the processor 11 executes the processing of the flowchart shown in FIG. 6 as, for example, a job of a fixed cycle every 10 milliseconds. The other conditions are the same as those shown in FIG.

  Step S101: The processor 11 determines whether or not the shipping inspection mode is on standby. When the shipping inspection mode is in standby (step S101: Yes), the process proceeds to step S102. When the shipping inspection mode is not in standby (step S101: No), the shipping inspection mode is already in progress. The processing of the flowchart shown is ended.

  As described later, during the shipping inspection mode, the processor 11 executes the processing of the flowchart shown in FIG. Therefore, every time the processor 11 starts the processing of the flowchart shown in FIG. 6 as a job of a fixed cycle in parallel processing, the determination processing of the negative side is performed in step S101, and thus the processing of steps S102 to S104 described below Exit without executing.

  Step S102: The processor 11 determines whether the first signal (AAh) and the second signal (55h) are being received alternately each time the processing of the flowchart shown in FIG. 6 is repeated. When the first signal (AAh) and the second signal (55h) are being received alternately (Step S102: Yes), the process proceeds to Step S103, and when not being received (Step S102: No), FIG. The processing of the flowchart shown is ended.

  Step S103: The processor 11 determines whether the specified number has been reached. Specifically, the processor 11 determines whether or not the first signal (AAh) and the second signal (55h) are alternately and continuously received a specified number of times. If this determination condition is satisfied (step S103: Yes), the process proceeds to step S104. When this determination condition is not satisfied (step S103: No), the processing of the flowchart shown in FIG. 6 is ended.

  Step S104: The processor 11 shifts to the shipping inspection mode. That is, the processor 11 switches from waiting for the shipping inspection mode to the shipping inspection mode. Then, the processor 11 ends the processing of the flowchart shown in FIG. 6 and executes the processing of the flowchart shown in FIG. 7 as processing of the shipping inspection mode.

  FIG. 7 is a flowchart showing an example of the operation of the inspection method in the present embodiment. FIG. 8 is a diagram for explaining an example of a timing chart at the normal time in the present embodiment. FIG. 9 is a diagram for explaining an example of a timing chart in the case of performing control processing to suppress the release of the shipping inspection mode at an unexpected timing in the present embodiment.

  The processor 11 executes the processing of the flowchart shown in FIG. 6 as, for example, a job of a fixed cycle every 10 ms, but the sampling cycle is shorter than the transmission cycle (10 ms) and shown in FIG. The processing of the flowchart is executed as, for example, a 2 millisecond fixed cycle job. That is, in the present embodiment, the sampling cycle is set to 1/2 or less of the transmission cycle. In this case, as shown in FIG. 9, it is possible to suppress an acquisition leak of the inspection command signal.

  Step S201: The processor 11 determines whether or not the shipping inspection mode is in progress. Specifically, the processor 11 reads the data of the inspection command signal output from the inspection device 3 and stored in the RAM 14 in time series, and determines whether or not the shipping inspection mode is in progress based on the data string. When the shipping inspection mode is in progress (step S201: Yes), the process proceeds to step S202. On the other hand, when the shipping inspection mode is not in progress (step S201: No), the processing of the flowchart shown in FIG. 7 is ended. That is, in this case, it means that the processor 11 is switched from the shipping inspection mode to the shipping inspection mode standby state.

  Step S202: The processor 11 determines whether or not the first signal (AAh) and the second signal (55h) are being alternately received. When the first signal (AAh) and the second signal (55h) are being received alternately (step S202: Yes), the processing of the flowchart shown in FIG. 7 is ended. On the other hand, when it is not receiving (step S202: No), it transfers to the process of step S203.

  Step S203: The processor 11 determines whether the specified number has been reached. Here, when the shipping inspection mode is normally ended from the inspection device 3 side, for example, only the first signal (AAh) is continuously output. Accordingly, when the processor 11 receives the first signal (AAh) a prescribed number of times, the processor 11 proceeds to the process of step S204 as a case where the determination condition is satisfied (step S203: Yes). When this determination condition is not satisfied (step S203: No), the processing of the flowchart shown in FIG. 7 is ended.

  Step S204: The processor 11 makes a transition again while waiting for the shipping inspection mode. Then, the processor 11 ends the processing of the flowchart shown in FIG. 7 and executes the processing of the flowchart shown in FIG. 6 again. Hereinafter, the inspection method according to the present embodiment will be described with reference to the timing charts of FIGS.

  When the processor 11 is switched from the standby state in the shipping inspection mode to the shipping inspection mode in the normal state shown in FIG. 8, the processor 11 acquires the inspection command signal by shortening the sampling period with respect to the initially set transmission period. In FIG. 8, since the first signal (AAh) and the second signal (55h) can be alternately acquired even if the sampling period is thus shortened, the processor 11 can normally perform the inspection process in the shipping inspection mode. It can be done.

  Further, as shown in FIG. 9, even when the transmission cycle fluctuates, the sampling cycle is shortened with respect to the initially set transmission cycle, so that the acquisition omission of the inspection command signal does not occur. The first signal (AAh) and the second signal (55h) can be alternately acquired. Therefore, the processor 11 can normally execute the process of inspection in the shipping inspection mode.

  In the present embodiment, the minimum value of the sampling cycle may be set to 1/2 or more of the settable minimum transmission cycle of the communication protocol. Even in the case of such a condition, in the present embodiment, the release of the shipping inspection mode at an unexpected timing can be suppressed.

  Further, in the above-described embodiment, switching of the shipping inspection mode is illustrated to simplify the description, but the shipping inspection mode may be switched from among a plurality of modes.

As described above, in the present embodiment, by suppressing the acquisition omission of the inspection command signal, the release of the shipping inspection mode at an unexpected timing can be suppressed, and the reliability of the inspection can be enhanced. Thereby, inspection accuracy can be improved. Furthermore, the technology of the present disclosure is not limited to the shipping inspection mode in the technical idea, and the scope of application can be extended to a system that suppresses the release of the mode at an unexpected timing.
[Supplementary matter of the above embodiment]
Technical ideas other than claims which can be grasped from the above embodiment will be described together with effects below.
(A) The electronic control unit and the inspection unit for supplying the command signal communicate using a CAN or FlexRay (registered trademark) communication protocol,
3. The electronic control unit according to claim 2, wherein the minimum value of the sampling period of the command signal is equal to or more than 1/2 of the settable minimum transmission period of the communication protocol.
According to the above technical idea, by setting the sampling cycle to the above condition, it is possible to suppress the release of the mode at an unexpected timing.
The electronic control device according to any one of claims 1 to 3, wherein the predetermined mode is ended when the command signal is not obtained by a specified number of times during execution of the mode. .
According to the above technical idea, the mode can be ended normally by ending the mode according to the prescribed number of times.
(C) During the execution of the mode, the mode is ended when a state in which an interval for sampling the command signal is twice or more of the time interval continues for a prescribed number of times. The electronic control unit according to any one of the above.
According to the above technical idea, the mode can be ended normally by ending the mode according to the prescribed number of times.
(D) The command signal is composed of a first signal consisting of a predetermined bit value of n base number and a second signal consisting of a bit value obtained by inverting the bit value, and the first signal and the second signal 4. The electronic control device according to claim 3, wherein the external device alternately outputs at intervals of time from the external device.
According to the above technical idea, the command signal can be simplified to maintain the mode.
(E) A method of testing an electronic control unit for a motor vehicle that switches to a predetermined mode according to a command signal that changes according to a predetermined rule, and maintains the predetermined mode while the command signal continues. The inspection method characterized in sampling the command signal at a cycle shorter than a time interval at which the command signal changes, at least while the predetermined mode is being executed.
According to the above technical idea, by executing the above-described process, it is possible to provide an inspection method which suppresses the release of the mode at an unexpected timing.
(F) A program of an electronic control unit for an automobile, which is switched to a predetermined mode according to a command signal which changes according to a predetermined rule, and which maintains the predetermined mode while the command signal is continuous, A program for executing processing of sampling the command signal at a cycle shorter than a time interval at which the command signal changes at least while the predetermined mode is being executed.
According to the above technical idea, by causing the program to execute the above process, it is possible to suppress the release of the mode at an unexpected timing.

  As mentioned above, although embodiment indicated to this matter was explained using a specification, a drawing, etc., art of this indication is not limited to the above-mentioned embodiment, and various change in the range which does not deviate from the meaning of the present invention Is possible.

1 ... ECU
2 ... Network cable 3 ... Inspection device 11, 31 ... Processor 12, 32 ... Communication circuit 13 ... ROM
14 ... RAM
15, 35: Bus 33: Storage 34: I / O device

Claims (3)

Switching to an inspection mode in which the processing of the inspection is performed according to a command signal including a first signal and a second signal alternately output in a predetermined transmission cycle and instructing processing of the inspection regarding the vehicle, The electronic control unit for a car continues to maintain the inspection mode until the end of the inspection as long as the first signal and the second signal are alternately acquired without leakage .
The transmission by sampling the first signal and the second signal at a period shorter than a time interval at which the first signal and the second signal alternately change at least while the inspection mode is being performed. Even if the cycle fluctuates, it is possible to suppress acquisition of the command signal,
Electronic control unit for automobiles characterized by The sampling period of the command signal is not more than half of the time interval,
The electronic control unit according to claim 1, characterized in that: The command signal is supplied from an external device that is detachably connected via a network cable.
The electronic control device according to claim 1 or 2, characterized in that: