Electronic control device

Abstract

To provide an electronic control device capable of determining whether the period is abnormal before the ignition switch is turned off last time, even if BIST is not executed when the ignition switch is turned on next time.SOLUTION: A BIST circuit 19 executes BIST of a diagnosis target circuit 20 of a power supply monitoring circuit 18 at least during the period when a main relay 5 is held ON from an OFF state of the ignition switch until the main relay transitions to the OFF state (t1-t3), and after starting by a soak timer T1 from the OFF state of the ignition switch (t4). A microcomputer 13 diagnoses normality or abnormality based on the execution result of the BIST circuit 19.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic control device. [Background technology]

[0002] For example, an electronic control unit mounted on a vehicle has a power supply circuit. This power supply circuit generates multiple power supplies to supply power to a microcomputer and peripheral circuits in response to power supplied from the vehicle battery. Since the power supply voltages output from these power supplies must be at a predetermined rated value, the power supply circuit is equipped with a power supply monitoring circuit that monitors whether the power supply voltages are at the rated value.

[0003] Conventionally, electronic control devices have been known that have a hardware self-test (hereinafter referred to as BIST) function for this power supply monitoring circuit (see, for example, Patent Document 1). This proposes a technology that re-runs a diagnosis if the power supply monitoring circuit determines that there is an abnormality, and concludes that there is an abnormality if the circuit determines that there is an abnormality a predetermined number of times in succession. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-154993 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, BIST is executed when the ignition switch is turned from off to on, or while the main relay is held on from when the ignition switch is turned off until the main relay is turned off. If BIST is executed when the ignition switch is turned from off to on, a problem occurs in that it takes a long time for the microcomputer to be released from reset and start operating.

[0006] Furthermore, if the BIST execution unit executes BIST between the time the ignition switch is turned off and the time the main relay is turned off while the main relay is being held on, the operation delay time can be reduced by not executing BIST the next time the ignition switch is turned on. However, when the technology described in Patent Document 1 is applied, if BIST is not executed the next time the ignition switch is turned on, a problem occurs in that it is not clear whether an abnormality occurred between then and the time the ignition switch was turned off the previous time.

[0007] The present invention has been made in consideration of the above circumstances, and its purpose is to provide an electronic control device that can determine whether there is an abnormality between the time the ignition switch is last turned off and the time the ignition switch is last turned on, without having to execute a BIST the next time the ignition switch is turned on. [Means for solving the problem]

[0008] The invention of claim 1 is directed to an electronic control device having a hardware self-test (hereinafter referred to as BIST) function of a power supply monitoring function by a power supply monitoring device. According to the invention described in claim 1, the BIST execution unit executes BIST of the circuit to be diagnosed at least while the main relay is held on from the off state of the ignition switch until the main relay transitions to the off state, and when started by a soak timer from the off state of the ignition switch (hereinafter referred to as soak start), and the diagnosis unit performs normal / abnormal diagnosis based on the execution result of the BIST execution unit.

[0009] Because the BIST execution unit executes the BIST of the circuit to be diagnosed at soak startup, the diagnostic unit can perform a normal / abnormal diagnosis in advance before the next ignition switch is turned on. This makes it possible to determine whether there is an abnormality before the ignition switch is turned off, eliminating the need to execute the BIST the next time the ignition switch is turned on, and shortening the operation time at the next startup. [Brief explanation of the drawings]

[0010] [Figure 1] A functional block diagram showing the configuration of an electronic control device according to a first embodiment. [Figure 2] 1 is a time chart outlining the flow of diagnostic operations in the first embodiment; [Figure 3] Flowchart 1 for explaining the flow of diagnostic operations in the first embodiment [Figure 4] Flowchart 2 for explaining the flow of diagnostic operations in the first embodiment [Figure 5] Flowchart 1 for explaining the flow of diagnostic operations in the first embodiment [Figure 6] 10 is a time chart for explaining the flow of a diagnostic operation in the second embodiment; [Figure 7] 10 is a time chart for explaining the flow of a diagnostic operation in the third embodiment; [Figure 8] 10 is a flowchart illustrating the flow of a diagnostic operation in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the electronic control device will be described with reference to the drawings. In each embodiment, substantially the same or similar parts are designated by the same or similar reference numerals, and descriptions thereof may be omitted as necessary.

[0012] (First embodiment) A first embodiment will be described below with reference to Figures 1 to 5. The ECU 1 shown in Figure 1 controls, for example, an engine mounted on a vehicle. The ECU 1 has a BATT terminal 3 and a +B terminal 4 as power supply terminals for receiving power from an on-board battery 2. The BATT terminal 3 is directly connected to the positive side of the on-board battery 2. The +B terminal 4 is connected to the positive side of the on-board battery 2 via a switch 6 of a main relay 5. The ECU 1 corresponds to an electronic control device.

[0013] In addition to a BATT terminal 3 and a +B terminal 4, the ECU 1 is also equipped with a J1 terminal 7, a J2 terminal 8, and a J3 terminal 9. The J1 terminal 7 is directly connected to the positive side of the vehicle battery 2. The J2 terminal 8 is connected to ground via a coil 10 of the main relay 5. The J3 terminal 9 is connected to the positive side of the vehicle battery 2 via a switch 11 that turns on and off in response to a signal from an ignition switch IGSW. The on state of the switch 11 is not limited to vehicles having an engine, but also includes the power on state of electric vehicles and hybrid vehicles, for example.

[0014] The ECU 1 includes a power supply circuit 12, a microcomputer 13, and a relay control circuit 14. The microcomputer 13 corresponds to the control circuit. The input terminals of the power supply circuit 12 are connected to a BATT terminal 3 and a +B terminal 4, and power can be supplied from the vehicle battery 2 via the BATT terminal 3 and the +B terminal 4. The power supply circuit 12 generates multiple power sources in response to the power supply from the vehicle battery 2.

[0015] Although detailed explanation will be omitted here, the power supply circuit 12 generates four types of power supply voltages: a power supply voltage for the main power supply of the microcontroller 13 and the relay control circuit 14, a power supply voltage for the main power supply of the core that constitutes the microcontroller 13, a power supply voltage for the standby power supply of the relay control circuit 14, and a power supply voltage for the standby power supply of the microcontroller 13.

[0016] The power supply circuit 12 has a so-called power-on reset function that outputs a reset signal to the microcomputer 13 until its output power supply voltage stabilizes. The microcomputer 13 has a processor such as a CPU (not shown), and memories such as ROM and RAM, and executes various control programs for controlling the engine that are stored in the ROM. The memory refers to a non-transitory tangible storage medium that non-temporarily stores computer-readable programs and data. The non-transitory tangible storage medium is realized by a semiconductor memory or the like.

[0017] The relay control circuit 14 includes an input circuit 15, an OR circuit 16, and a switching element 17. The input terminal of the input circuit 15 is connected to the J3 terminal 9, and the output terminal is connected to the input terminal of the microcomputer 13. The input terminal of the OR circuit 16 is connected to the input circuit 15 and the output terminal of the microcomputer 13. One end of the switching element 17 is connected to the J1 terminal 7, and the other end is connected to the J2 terminal 8. The switching element 17 is controlled to be turned on / off in accordance with the output from the OR circuit 16.

[0018] The power supply circuit 12 is equipped with a power supply monitoring circuit 18. The power supply monitoring circuit 18 is equipped with a BIST circuit 19 that determines whether a circuit 20 to be diagnosed by the power supply monitoring circuit 18 is normal or abnormal. Here, BIST stands for hardware self-test, and the power supply monitoring circuit 18 is equipped with a hardware self-test function thanks to the BIST circuit 19. The circuit 20 to be diagnosed by the power supply monitoring circuit 18 is, for example, a comparator for voltage comparison or a digital circuit that constitutes the power supply circuit 12. The BIST circuit 19 determines whether the logic operation of the circuit to be diagnosed 20 and the voltages of each component are abnormal, and stores the BIST execution results in a predetermined storage area such as an internal register or non-volatile memory. The stored BIST execution results are obtained from the microcontroller 13 after the microcontroller 13 starts up. The microcontroller 13 functions as a diagnostic unit that performs normal / abnormal diagnosis based on the BIST execution results of the BIST circuit 19.

[0019] <Operation when the ignition switch IGSW transitions from the on state to the off state> The operation when the ignition switch IGSW is turned from on to off to stop the engine after the engine has started will be described with reference to Figures 2 and 3. As shown in Figure 2, when the ignition switch IGSW is turned from on to off, the soak timer T1 starts counting (timing t1).

[0020] When switch 11 is turned off in response to operation of ignition switch IGSW, this information is input to microcomputer 13 via input circuit 15, and microcomputer 13 executes shutdown processing from timing t1. When executing shutdown processing, microcomputer 13 finally turns off switch 6 of main relay 5 (see timing t3). For this reason, microcomputer 13 does not turn off switch 6 of main relay 5 immediately after starting shutdown processing at timing t1.

[0021] When the microcomputer 13 executes the shutdown process, it sends a BIST execution command to the power supply monitoring circuit 18 of the power supply circuit 12. Then, the BIST circuit 19 executes the BIST while the main relay 5 continues to be on (see timing t2). In the following explanation, the execution result of the BIST performed while the main relay 5 continues to be on after the ignition switch IGSW has changed from on to off will be referred to as "BIST execution result A."

[0022] The power supply monitoring circuit 18 acquires the BIST execution result A and stores it in a predetermined storage area. The microcomputer 13 acquires the BIST execution result A and stores it in a predetermined internal storage area. After that, when the microcomputer 13 completes the shutdown process, it controls the switching element 17 via the OR circuit 16 to change the power supply state to the coil 10 and turn off the switch 6 of the main relay 5 (timing t3). The vehicle battery 2 stops power supply to the +B terminal 4. The microcomputer 13 transitions to a standby state.

[0023] The soak timer T1 continues counting even while the ignition switch IGSW is not turned on. After a predetermined time has elapsed, the count value of the soak timer T1 reaches a predetermined threshold value. When the count value of the soak timer T1 reaches the predetermined threshold value, the main relay 5 is turned on at timing t4. This causes the supply of power from the vehicle battery 2 to the +B terminal 4 of the power supply circuit 12, and the power supply circuit 12 begins generating power.

[0024] 3, the power supply circuit 12 determines whether the BIST diagnostic flag is off (S101), and if the BIST diagnostic flag is off, the BIST circuit 19 of the power supply circuit 12 executes BIST (BIST execution result F1: S102). If the BIST diagnostic flag is on, the process skips S102 and proceeds to S103. After that, when power is supplied to the microcomputer 13 and the microcomputer 13 starts up, the software is initialized for soak processing (S103 in FIG. 3).

[0025] After that, when the microcomputer 13 has completed booting, it determines by software whether the BIST diagnostic flag is off (S104). If the BIST diagnostic flag is off, the microcomputer 13 acquires the BIST execution result F1 (S105). The microcomputer 13 then stores the BIST execution result F1 in a predetermined internal storage area. Note that the soak timer T1 stops counting when it reaches a threshold value.

[0026] The microcomputer 13 executes the BIST normal / abnormal diagnosis (S106). At this time, as shown in Fig. 4, the microcomputer 13 refers to the BIST execution result A and the BIST execution result F1, and if it determines that both are normal in S151, it determines that the power supply monitoring circuit 18 is normal and regards the BIST diagnosis result as normal (S152).

[0027] If the microcomputer 13 determines that the power supply monitoring circuit 18 is normal, it turns on the BIST diagnostic flag (timing t4a in FIG. 2: S108 in FIG. 3). The microcomputer 13 writes data to a predetermined storage area inside the power supply monitoring circuit 18 so that the BIST will not be executed the next time the ignition switch is turned on after being turned off.

[0028] Conversely, if either the BIST execution result A or the BIST execution result F1 is abnormal in S151 of Fig. 4, or if either the BIST execution result A or F1 is not recorded, the microcomputer 13 determines that the power supply monitoring circuit 18 is abnormal and determines that the BIST diagnosis is abnormal (S153).The microcomputer 13 determines that the BIST diagnosis is abnormal in S107 of Fig. 3, and keeps the BIST diagnosis flag off (S109 of Fig. 3).

[0029] Thereafter, the microcomputer 13 performs soak control and performs shutdown processing, and then turns off the power (S110 to S112 in FIG. 3). During the series of processing steps S110 to S112, the count of the soak timer T1 is cleared at timer clear timing t5. Also during the series of processing steps, the microcomputer 13 turns off the main relay 5 and returns to the standby state (timing t6 in FIG. 2). Thereafter, when the ignition switch IGSW is turned on from the off state, the power supply circuit 12 starts up and the main relay 5 is turned on. Then, the processing shown in FIG. 5 is executed.

[0030] <If the BIST execution result at the previous soak start was normal> If the BIST execution result at the previous soak startup was normal, a BIST diagnostic flag is stored as ON in a predetermined storage area inside the power supply monitoring circuit 18. In this case, when the power supply circuit 12 generates power, the BIST circuit 19 of the power supply monitoring circuit 18 determines whether the BIST diagnostic flag is OFF (S201). In this case, the BIST circuit 19 determines NO in S201 and therefore does not execute BIST.

[0031] After that, when the microcomputer 13 starts up, it performs software initialization (S203). The microcomputer 13 determines whether the BIST diagnostic flag is off (S204) by software. The microcomputer 13 references the BIST diagnostic flag and determines NO in S204. In this case, the microcomputer 13 proceeds to S207 without acquiring the BIST result, and executes normal control in S207. Note that the BIST execution result A, the BIST execution result F1, and the BIST diagnostic flag are cleared by the microcomputer 13 in processing after turning on the ignition switch IGSW (timing t7 in FIG. 2).

[0032] <If the BIST execution result at the previous soak startup was abnormal> Conversely, the operation when the BIST execution result at the previous soak start-up was abnormal will be described. The BIST diagnostic flag is stored as OFF in a predetermined storage area inside the power supply monitoring circuit 18. In this case as well, the power supply circuit 12 generates power, and the BIST circuit 19 determines whether the BIST diagnostic flag is OFF (S201). The power supply circuit 12 determines YES in S201 and executes BIST for the power supply monitoring circuit 18. The BIST execution result executed when the ignition switch IGSW is turned ON from the OFF state will be referred to below as "BIST execution result B."

[0033] When the microcomputer 13 starts up, it performs software initialization (S203). The microcomputer 13 determines whether the BIST diagnosis flag is off in software (S204). The microcomputer 13 determines YES in S204, obtains BIST execution result B from the internal storage area of ​​the power supply monitoring circuit 18 (S205), and stores BIST execution result B in a predetermined internal storage area of ​​the microcomputer 13. The microcomputer 13 then performs normal / abnormal BIST diagnosis (S206).

[0034] The microcomputer 13 performs a BIST normal / abnormal diagnosis based on the BIST execution result B acquired in S205, the previous BIST execution result A executed while the main relay 5 was held on, and the BIST execution result F1 at soak startup (S206). At this time, the microcomputer 13 performs a normal / abnormal diagnosis on the three (multiple) BIST execution results. The microcomputer 13 may diagnose the device as normal only if all three (multiple) BIST execution results are normal. The microcomputer 13 then stores the normal / abnormal diagnosis results in a predetermined storage area.

[0035] Thereafter, the microcomputer 13 performs normal control (S207) until the ignition switch IGSW is turned off (S208). After the shutdown process (S209), the microcomputer 13 executes BIST (S210), stores BIST execution result A in a predetermined internal storage area (S211), and turns off the power (S212).

[0036] <Summary of this embodiment> In this embodiment, the BIST circuit 19 of the power supply monitoring circuit 18 executes BIST while the main relay 5 is held on from the off state of the ignition switch IGSW until the main relay 5 transitions to the off state, and at soak startup. In this case, if both are normal, the startup BIST is not executed the next time the ignition switch IGSW is turned on from off.

[0037] In the specific flow described above, if the BIST diagnosis flag is on in S201, normal / abnormal diagnosis of the power supply monitoring circuit 18 has already been completed, eliminating the need to execute BIST in S202. This reduces the operational delay time of the microcomputer 13 when the ignition switch IGSW is turned on after being turned off, thereby shortening the startup time of the ECU 1. In other words, because normal / abnormal diagnosis can be performed in advance, it is not necessary to execute BIST when the ignition switch IGSW is turned on, thereby reducing the startup time of the microcomputer 13. The power supply voltage generated by the power supply circuit 12 tends to become unstable when it is started up, but this eliminates the need to execute BIST when the power supply circuit 12 is started up, allowing for stable acquisition of BIST execution results.

[0038] Furthermore, even when the BIST circuit 19 executes BIST (S202) when it is determined in S201 that the BIST diagnostic flag is off, diagnosis can be performed by comparing the BIST execution result A executed in advance from when the ignition switch IGSW is turned off until the main relay 5 is turned off with the BIST execution result F1 at the time of soak startup.

[0039] When the ignition switch IGSW is turned on, the engine starts. While the engine is running, a relatively large amount of electrical noise is generated. Therefore, if the BIST circuit 19 determines an abnormality based on a single abnormality determination, robustness against misdiagnosis due to electrical noise is reduced. According to the operation of this embodiment, robustness can be maintained high by performing BIST determination multiple times. Even in this case, the execution time of BIST can be shortened compared to when BIST is performed multiple times upon startup of the power supply circuit 12. As a result, the operational delay time of the microcomputer 13 can be shortened, and the startup time of the ECU 1 can be shortened.

[0040] After the ignition switch IGSW is turned off, the microcomputer 13 checks the BIST execution result A, which is executed during the soak timer T1 activation while the main relay 5 is held on until it is turned off, and the BIST execution result F1 at soak activation. If either the BIST execution result A or F1 indicates an abnormality, or if the BIST execution result A or F1 does not exist, the microcomputer 13 determines that an abnormality has occurred and executes the BIST the next time the ignition switch IGSW transitions from an off state to an on state. Compared to executing the BIST multiple times at startup, normal / abnormal diagnosis can be performed while reducing the number of BIST executions. This allows for a shorter startup time while maintaining robustness.

[0041] (Second embodiment) A second embodiment will be described with reference to Fig. 6. In the second embodiment, a case will be described in which a relatively long period of time elapses between when the ignition switch IGSW is turned off and the engine is stopped, and when the ignition switch IGSW is turned on again. As in the previous embodiments, once the engine is stopped, the microcomputer 13 is activated by the soak timer T1 at predetermined intervals (for example, every few hours, every day, or every week), and soak control is executed each time.

[0042] In such a case, processing is performed as shown in Fig. 6. The power supply circuit 12 and the microcomputer 13 perform processing for the first soak control in the same manner as in the first embodiment, as shown at timings t1 to t6 in Fig. 6. Here, as shown in Fig. 6, the explanation will be given assuming that the microcomputer 13 acquires a BIST execution result A as an abnormality at timing t2 before the main relay 5 is turned off, and acquires a BIST execution result F2 as a normality at timing t4 when the soak is started.

[0043] Thereafter, as shown at timings t14 to t16 in Figure 6, at the time of the second soak startup, the microcomputer 13 holds the BIST execution result F2 from the first soak startup along with the BIST execution result A. At this time, if the BIST normal / abnormal diagnosis result is normal, the BIST diagnostic flag is on and the BIST is not executed even at the soak startup. However, in the case shown in Figure 6, the BIST execution result A is abnormal, so the microcomputer 13 holds the BIST diagnostic flag off and executes the BIST at the second soak startup (timing t14: BIST execution result F3).

[0044] At timing t14a, the microcomputer 13 performs a normal / abnormal diagnosis based on the BIST execution results A, F2, and F3 acquired up to that point. At this time, the microcomputer 13 may diagnose the device as normal if the BIST execution result A and all of the BIST execution results F2 and F3 executed at soak startup are normal.

[0045] However, particularly when the BIST is executed multiple times after the ignition switch IGSW is turned off and before it is turned on again, it may be determined that the system is normal if the most recent predetermined number of executions are normal. In this case, if the most recent BIST execution results F2 and F3 are normal, the microcomputer 13 may determine that the system is normal and turn on the BIST diagnosis flag.

[0046] In the case of FIG. 6 , the microcomputer 13 turns on the BIST diagnostic flag at timing t14a because the two most recent BIST execution results F2 and F3 are normal. In the case shown in FIG. 6 , the BIST execution results F2 and F3 are normal twice during soak startup. However, this is not limited to two BIST executions, and the number of BIST executions may be three or more. For example, if soak startup occurs five times between the time the ignition switch IGSW is turned off and the time it is turned on again, the microcomputer 13 may refer to the most recent two, three, or four BIST execution results and obtain the normal / abnormal BIST results. Note that the BIST execution result A, the BIST execution results F2 and F3, and the BIST diagnostic flag are cleared by the microcomputer 13 after the ignition switch IGSW is turned on (timing t17 in FIG. 6 ). The remaining flow is similar to that of the previous embodiment, and therefore will not be described further.

[0047] According to this embodiment, when the soak timer T1 is used to repeatedly start the power supply circuit 12, the BIST circuit 19 of the power supply circuit 12 executes a BIST at each soak start. The microcomputer 13 then performs a normal / abnormal diagnosis based on the BIST execution results F2 and F3 from the most recent predetermined number of soak start times. Even if the BIST execution result A is abnormal or no BIST execution result (e.g., A) is recorded, the microcomputer 13 can execute the BIST at each soak start to increase the number of diagnostic attempts. Therefore, if the microcomputer 13 can determine that the normal / abnormal diagnosis result at soak start is normal, the microcomputer 13 can omit the execution of the BIST the next time the ignition switch IGSW is turned on, thereby shortening the startup time of the microcomputer 13 the next time the ignition switch IGSW is turned on.

[0048] (Third embodiment) A third embodiment will be described with reference to Figures 7 and 8. In the third embodiment, a configuration will be described in which the results of BIST execution are not used for diagnosis if a predetermined time has elapsed since the execution of BIST. Also, a configuration will be described in which BIST is executed between the end timing of the soak process executed at soak startup and the time when the main relay 5 is turned off at soak startup. In this embodiment, the power supply circuit 12 further includes another timer T2 in addition to the soak timer T1.

[0049] 7, when the ignition switch IGSW is turned off at timing t1, the soak timer T1 starts counting (timing t1). After that, while the main relay 5 is kept on, the BIST circuit 19 executes the BIST (timing t2: BIST execution result A).

[0050] At timing t2, the power supply circuit 12 starts counting a timer T2, which is provided to determine whether a predetermined time has elapsed since the previous BIST execution result (e.g., A) was obtained.

[0051] This timer T2 is set to reach a predetermined threshold at timing ta after a predetermined period of time when the soak timer T1 starts the soak and during startup of the microcomputer 13. After the BIST circuit 19 executes the BIST, the switch 6 of the main relay 5 is turned off (BIST execution result A: timing t3). Then, the microcomputer 13 acquires the BIST execution result A and stores it in a predetermined storage area, then performs a shutdown process and transitions to a standby state.

[0052] Thereafter, when the count value of the soak timer T1 reaches the threshold value, the main relay 5 is turned on. The power supply circuit 12 starts generating power and supplies it to the microcomputer 13. The BIST circuit 19 of the power supply circuit 12 determines whether the BIST diagnostic flag is off (S301 in FIG. 8). If the BIST diagnostic flag is on, the BIST circuit 19 of the power supply circuit 12 executes BIST (S302: BIST execution result F4).

[0053] When the microcomputer 13 starts up, it initializes the software for soak processing (S303). After that, when the microcomputer 13 completes startup, it determines by software whether the BIST diagnostic flag is off (S304). If the BIST diagnostic flag is off, the microcomputer 13 acquires the BIST execution result F4 from a predetermined storage area in the power supply monitoring circuit 18 (S305). The microcomputer 13 then stores the BIST execution result F4 in a predetermined internal storage area. Note that the soak timer T1 stops counting up once it reaches the threshold value.

[0054] The microcomputer 13 executes a BIST normal / abnormal diagnosis (S306). At this time, the same process as in Fig. 4 is executed. The microcomputer 13 refers to the BIST execution result A and the BIST execution result F4, and if it determines that both are normal in S151 of Fig. 4, it determines that the power supply monitoring circuit 18 is normal and regards the BIST diagnosis result as normal (S152 of Fig. 4).

[0055] 4, if either the BIST execution result A or the BIST execution result F1 is abnormal, or if either the BIST execution result A or the BIST execution result F1 is not recorded, the microcomputer 13 determines that the diagnosis target circuit 20 of the power supply monitoring circuit 18 is abnormal and determines that the BIST diagnosis is abnormal (S153). The microcomputer 13 keeps the BIST diagnosis flag off.

[0056] Thereafter, the microcomputer 13 executes soak control (S307) and then performs shutdown processing (S308), as shown in FIG. 8. During this series of processing, the microcomputer 13 determines whether the BIST execution result A and the normal / abnormal diagnosis result by F4 are normal. It also determines whether a certain predetermined time has passed since the previous BIST execution result (e.g., A) was obtained. This determination is made by determining whether the count value of timer T2 has reached a threshold value.

[0057] If the final diagnosis result by the BIST execution result A and F4 is abnormal, or if the timer T2 has already reached the threshold value, it is determined as NO in S309, and in case of an abnormality, the BIST is executed again by the BIST circuit 19 (S311: BIST execution result F5).

[0058] <In S309, when the diagnosis result by the BIST execution result A and F4 is determined to be abnormal> When the diagnosis result by the BIST execution result A and F4 is abnormal, that is, when any of the BIST execution results A and F4 is abnormal, or when the BIST execution result A or F4 is not recorded, the microcomputer 13 commands the power supply monitoring circuit 18 to execute the BIST, and the BIST circuit 19 executes the BIST. Then, the microcomputer 13 acquires the BIST execution result F5 from the BIST circuit 19 (S312).

[0059] The microcomputer 13 refers to the BIST execution result A when the previous main relay 5 was held on, the BIST execution result F4 at the time of soak start, and the BIST execution result F5 acquired in S312 as necessary, and executes a normal-abnormal diagnosis (S313).

[0060] The microcomputer 13 refers to the diagnosis result in S314. If the microcomputer 13 determines the diagnosis result as normal by determining that the BIST execution results F4 and F5 for the two most recent times are normal, it turns on the BIST diagnosis flag in S310 and writes to a predetermined storage area inside the power supply monitoring circuit 18 so that the next BIST execution is not performed. In this case, there is no need to execute the BIST at the next startup. As a result, the operation delay time of the microcomputer 13 when the ignition switch IGSW is turned on next time can be shortened, and the startup time of the ECU1 can be shortened.

[0061] If, for example, when the microcomputer 13 refers to the BIST execution results A, F4, and F5 for three times and determines that the diagnostic result is abnormal if any one of them is abnormal, the diagnostic result is determined to be abnormal. If the diagnostic result is abnormal, the BIST diagnostic flag is turned off in S315, and then the power is turned off (S316). In this case, when the next ignition switch IGSW is turned on, the BIST circuit 19 of the power supply monitoring circuit 18 executes BIST.

[0062] Thereby, the microcomputer 13 performs normal / abnormal diagnosis based on the BIST execution result A when the previous main relay 5 was held on and the BIST execution result F4 at the time of soak startup. Even if the diagnostic result is abnormal, by executing BIST again at the time of soak startup and obtaining the BIST execution result F5, a highly robust diagnosis can be performed.

[0063] <If the timer T2 has already reached the threshold value in S309> Also, if the timer T2 has reached the threshold value in S309, that is, if a predetermined time has elapsed since the BIST execution timing (for example, timing t2), the reliability of the BIST execution result A is considered low. In this case, the microcomputer 13 commands the BIST circuit 19 to execute BIST again (timing tb in FIG. 7). At this time, the BIST circuit 19 executes BIST again between the end timing of the soak process by the microcomputer 13 and turning off the main relay 5. The microcomputer 13 can perform a highly robust diagnosis by performing normal / abnormal diagnosis using the BIST execution results (for example, only F4 and F5) executed within a predetermined time close to the present.

[0064] Thereafter, the microcomputer 13 performs a normal / abnormal diagnosis, and if it determines that the ECU 1 is normal, it turns on the BIST diagnosis flag and writes this to a predetermined storage area in the power supply monitoring circuit 18 so that the BIST will not be executed the next time the ECU 1 is started (timing t24a). In this case, it is not necessary to execute the BIST the next time the ECU 1 is started. As a result, the operational delay time of the microcomputer 13 when the ignition switch IGSW is turned on the next time can be shortened, and the startup time of the ECU 1 can be shortened.

[0065] In this embodiment, the flow shown in Figure 7 shows a form in which two BIST execution results F4 and F5 are obtained at the time of soak startup to obtain a diagnostic result, but it is also possible to obtain three or more BIST execution results and determine the diagnostic result.

[0066] In this embodiment, if the microcomputer 13 determines that the normal / abnormal diagnosis result is abnormal, the BIST circuit 19 executes BIST while the main relay 5 is kept on from the time the soak is started until the main relay 5 is turned off, and the microcomputer 13 executes normal / abnormal diagnosis based on the execution result of BIST. This allows for highly robust diagnosis.

[0067] (Other embodiments) This embodiment is not limited to the above-described embodiment, and for example, the following modifications or extensions are possible. In the above description, when the soak timer T1 is started a predetermined number of times, a normal / abnormal diagnosis is performed based on the results of the BIST execution (e.g., A, F1 to F5, B) performed the most recent predetermined number of times while the ignition switch IGSW remains in the off state, but the present invention is not limited to this. For example, even if the ignition switch IGSW is turned on and off multiple times, the results of the BIST execution during that time may be stored in a non-volatile manner, and a normal / abnormal diagnosis may be performed based on the results of the BIST execution during that time.

[0068] In addition to the content set forth in the claims, the present disclosure also includes the following disclosure content. [1] An electronic control device having a hardware self-test (hereinafter referred to as BIST) function of a power supply monitoring function by a power supply monitoring device, a BIST execution unit (19) that executes a BIST of the circuit to be diagnosed at least while the main relay is held on from the off state of the ignition switch until the main relay transitions to the off state, and when the ignition switch is activated by a soak timer from the off state (hereinafter referred to as soak activation time); a diagnostic unit (13) that performs a normal / abnormal diagnosis based on the execution result of the BIST execution unit; An electronic control device comprising:

[0069] [2] The diagnostic unit After the ignition switch is turned off, the execution result (A) of the BIST execution unit executing the BIST during the activation of the soak timer while the main relay is kept on until the main relay is turned off is confirmed, and the execution result (F1) of the BIST execution unit at the time of the soak activation is confirmed. If the execution result of any of the BIST execution units indicates an abnormality, or if there is no execution result of the BIST execution unit, it is determined to be abnormal, and the BIST execution unit executes BIST the next time the ignition switch transitions from an off state to an on state [1].

[0070] [3] If the diagnostic unit determines that an abnormality has occurred, the BIST execution unit executes a BIST while the main relay is kept on from the time the soak is started until the main relay is turned off, and the diagnostic unit performs a normal / abnormal diagnosis based on the results of the BIST execution.

[0071] [4] When the soak timer is used to repeatedly start the electronic control device multiple times, the BIST execution unit executes the BIST at each of the multiple soak start times, and the diagnosis unit performs a normal / abnormal diagnosis based on the results of the BIST execution for the most recent predetermined number of times among the multiple times.

[0072] [5] If a predetermined time has passed since the previous execution of the BIST, the diagnostic unit does not use the results of the execution of the BIST for diagnosis, but executes the BIST by the BIST execution unit between the end of the soak process executed when the soak is started and the time when the main relay is turned off, and the diagnostic unit performs a normal / abnormal diagnosis based on the results of the BIST execution.

[0073] [6] An electronic control device according to any one of [1] to [5], wherein after the diagnostic unit diagnoses normality or abnormality, the results of the BIST executed while the main relay is kept on from the time the ignition switch is turned off until the main relay is turned off, and the results of the BIST executed at the time of soak startup are erased.

[0074] The techniques described in this disclosure may be implemented by a special purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the techniques described in this disclosure may be implemented by a special purpose computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the techniques described in this disclosure may be implemented by one or more special purpose computers configured with a processor comprising one or more hardware logic circuits in combination with a processor and memory programmed to perform one or more functions. Furthermore, a computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0075] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0076] In the drawing, 1 is an ECU (electronic control unit), 13 is a microcomputer (diagnostic unit), 18 is a power supply monitoring circuit (circuit to be diagnosed), and 19 is a BIST circuit (BIST execution unit).

Claims

1. An electronic control device having a hardware self-test (hereinafter referred to as BIST) function of a power supply monitoring function by a power supply monitoring device, a BIST execution unit (19) that executes a BIST of the circuit to be diagnosed at least while the main relay is held on from the off state of the ignition switch until the main relay transitions to the off state, and when the ignition switch is activated by a soak timer from the off state (hereinafter referred to as soak activation time); a diagnostic unit (13) that performs normal / abnormal diagnosis based on the execution result of the BIST execution unit; An electronic control device comprising:

2. The diagnostic unit After the ignition switch is turned off, an execution result (A) of the BIST execution unit executing the BIST during the activation of the soak timer while the main relay is kept on until the main relay is turned off is confirmed, and an execution result (F1) of the BIST execution unit at the time of activation of the soak timer is confirmed.

2. The electronic control device according to claim 1, wherein if any execution result of the BIST execution unit indicates an abnormality, or if there is no execution result of the BIST execution unit, it is determined to be abnormal, and the BIST execution unit executes a BIST the next time the ignition switch transitions from an off state to an on state.

3. 3. The electronic control device according to claim 2, wherein, when the diagnostic unit determines that an abnormality has occurred, the BIST execution unit executes a BIST while the main relay is kept on from the time the soak is started until the main relay is turned off, and the diagnostic unit performs a normal / abnormal diagnosis based on the results of the BIST execution.

4. 4. An electronic control device according to claim 2 or 3, wherein when the soak timer is used to repeatedly start the device multiple times, the BIST execution unit executes a BIST at each of the multiple soak start times, and the diagnosis unit performs a normal / abnormal diagnosis based on the results of the BIST execution for the most recent predetermined number of times among the multiple times.

5. 4. An electronic control device according to claim 2 or 3, wherein if a predetermined time has elapsed since the previous execution of the BIST, the diagnostic unit does not use the results of the execution of the BIST for diagnosis, and executes the BIST by the BIST execution unit between the end timing of the soak processing executed when the soak is started and the time when the main relay is turned off, and the diagnostic unit performs a normal / abnormal diagnosis based on the results of the BIST execution.

6. 4. The electronic control device according to claim 2, wherein after the diagnostic unit diagnoses normality or abnormality, the results of the BIST executed while the main relay is held on from the time the ignition switch is in the off state until the main relay is turned off, and the results of the BIST executed at the time of soak startup are erased.

Images