Engine control unit

Abstract

To provide a technology capable of inexpensively determining that a timing generating portion is abnormal without duplicating the timing generating portion generating false timing for executing engine control on the basis of a cam signal instead of a crank signal.SOLUTION: An engine control device 10 is equipped with actual false timing generating portions 54 and 56, a theory false timing generating portion 72, and an abnormality determining portion 72. The actual false timing generating portion generates actual false timing for executing engine control on the basis of a count number of an angle clock of a period generated by dividing an interval between current and previous cam signals with a multiplied number. The theory false timing generating portion generates a theory false timing of the actual false timing supposed to be generated by the actual false timing generating portion, on the basis of an interval between current and previous cam signals. The abnormality determining portion determines that the actual false timing generating portion is abnormal, when a difference between the actual false timing and the theory false timing is a predetermined value or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a technique for controlling an engine based on a cam signal instead of a crank signal. [Background technology]

[0002] When a crank signal, which is a pulse train generated at predetermined angular intervals in response to the rotation of the crankshaft, is normal, the vehicle engine control device generates an angle clock having a period obtained by dividing the pulse interval of the crank signal by a predetermined multiplication factor, and then controls the engine at a predetermined rotational angle position of the crankshaft indicated by the count number of the angle clock.

[0003] In response to this, there is known a technology in which, when the crank signal is abnormal, the engine is controlled based on a cam signal instead of the crank signal. When the engine is controlled based on the cam signal, for example, fail-safe engine control is performed to allow the vehicle to evacuate, rather than normal engine control.

[0004] In the technology described in Patent Document 1 below, when an abnormality occurs in the crank signal, an angle clock is generated by dividing the period of a cam signal instead of the crank signal by a multiplication factor, and engine control is performed according to the pseudo timing generated based on the count number of the angle clock. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4582252 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as a result of detailed investigation by the inventors, it was found that when an abnormality occurs in the timing generation unit, engine control is performed based on the pseudo timing generated by the abnormal timing generation unit.

[0007] If it can be determined that the timing generation unit that generates the pseudo timing is abnormal, appropriate action can be taken, such as halting engine control and stopping the vehicle. For example, by duplicating the timing generation unit and comparing the angle clock counts output by the two timing generation units, it can be determined that one of the timing generation units that generates the angle clock is abnormal. However, duplicating the timing generation unit that generates the angle clock to determine abnormality increases costs.

[0008] One aspect of the present disclosure is to provide a technology that can inexpensively determine that a timing generation unit is abnormal without duplicating the timing generation unit that generates pseudo timing to execute engine control based on a cam signal instead of a crank signal. [Means for solving the problem]

[0009] An engine control device according to one aspect of the present disclosure includes an actual pseudo timing generator (54, 56), a theoretical pseudo timing generator (72, S400 to S410, S434), and an abnormality determination unit (72, S420 to S432, S440, S470).

[0010] When the crank signal generated at a predetermined crank angle interval in response to the rotation of the engine crankshaft is abnormal, the actual pseudo timing generation unit generates an angle clock having a period obtained by dividing the interval between the current cam signal and the previous cam signal by a preset multiplication factor when the current cam signal is detected based on the cam signal generated at a predetermined cam angle interval in response to the rotation of the camshaft, and generates actual pseudo timing for engine control executed between the current cam signal and the next cam signal based on the count number of the angle clock.

[0011] In a cam interrupt process that is executed when a cam signal is detected, the theoretical pseudo timing generation unit generates theoretical pseudo timing of the actual pseudo timing that the actual pseudo timing generation unit is estimated to generate based on the number of angle clock counts, based on the interval between the current cam signal and the previous cam signal.

[0012] In a pseudo interrupt process started at the real pseudo timing generated by the real pseudo timing generation unit, the abnormality determination unit determines that the real pseudo timing generation unit is abnormal if the difference between the real pseudo timing and the theoretical pseudo timing generated by the theoretical pseudo timing generation unit is equal to or greater than a predetermined value.

[0013] With this configuration, an abnormality in the actual pseudo timing generation unit can be determined based on the difference between the actual pseudo timing generated by the actual pseudo timing generation unit and the theoretical pseudo timing generated by the theoretical pseudo timing generation unit, thereby making it possible to inexpensively determine an abnormality in the actual pseudo timing generation unit without duplicating the actual pseudo timing generation unit that generates the angle clock. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram showing the configuration of an engine control device according to a first embodiment. [Figure 2] FIG. 4 is a block diagram showing the configuration of a timer for a cam signal. [Figure 3] 10 is a flowchart showing a cam interrupt process. [Figure 4] 10 is a flowchart showing a pseudo interrupt process. [Figure 5] 4 is a time chart showing an abnormality in the angle clock generation circuit. [Figure 6] 10 is a flowchart showing a pseudo-interrupt process according to the second embodiment. [Figure 7] 6 is a time chart showing changes in an angle counter when the engine speed increases. [Figure 8] 10 is a flowchart showing a cam interrupt process according to a third embodiment. [Figure 9] 10 is a flowchart showing a pseudo interrupt process. [Figure 10] 6 is a time chart showing changes in an angle counter when the engine speed increases. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [1. First embodiment] [1-1.Configuration] 1 is used in an on-board ECU (Electronic Control Unit) for engine control such as injector injection control and fuel ignition control. ECU stands for Electronic Control Unit. The microcomputer 10 includes a free-running counter 20, timers 22 and 24, a timer circuit 30, an interrupt selector 60, and an engine controller 70.

[0016] The free-running counter 20 is a counter that measures time by counting clock signals with a fixed period. The count number of the free-running counter 20 returns to 0 when it overflows. The timers 22 and 24 form a dual system, and each receives a crank signal, which is a pulse train generated at predetermined angular intervals in response to the rotation of the crankshaft. The engine control unit 70 compares the outputs of the timers 22 and 24, and if they do not match, it determines that one of the timers 22 and 24 is abnormal. In this case, engine control is performed based on the cam signal instead of the crank signal.

[0017] The timers 22, 24 measure the crank signal interval, which is the period between pulse edges of the crank signal, and the crank timing when a pulse edge of the crank signal occurs, based on the count number of the free-running counter 20, and output the results to the engine control unit 70. In this embodiment, the crank angle interval, which represents the period of the crank signal, is 10° CA. CA is an abbreviation for Crank Angle.

[0018] The timer circuit 30 includes timers 40 and 50, an input switching unit 52, an angle clock generating circuit 54, and an angle timer 56. The timers 40 and 50 form a dual system. The engine control unit 70, which will be described later, compares the outputs of the timers 40 and 50, and if they do not match, it determines that one of the timers 40 and 50 is abnormal. In this case, appropriate fail-safe processing is performed, such as stopping the engine and stopping the vehicle.

[0019] A cam signal generated at a predetermined angular interval in response to the rotation of the camshaft is input to the timers 40, 50. In this embodiment, the cam angular interval representing the period of the cam signal is 180° CA. The timers 40, 50 output to the engine control unit 70 cam timing, which is the timing at which the rising or falling edge of the cam signal occurs, and a cam count, which is the number of counts of the rising or falling edges of the cam signal.

[0020] The timers 40 and 50 have substantially the same configuration, so the configuration will be described using the timer 40 as an example. Hereinafter, the rising edge or falling edge of the cam signal will also be referred to as a cam edge.

[0021] As shown in FIG. 2, the timer 40 includes an edge detection unit 42, a capture register 44, an increment unit 46, and an edge counter 48. The edge detection unit 42 detects a cam edge and outputs a detection signal of the cam edge as a cam interrupt request to the interrupt selection unit 60. When the edge detection unit 42 outputs the detection signal of the cam edge, the capture register 44 outputs the count number of the free-running counter 20 at that time as the cam timing.

[0022] When the edge detection unit 42 outputs a detection signal of a cam edge, the increment unit 46 increments the value of the edge counter 48 by 1 and sets the value in the edge counter 48. The edge counter 48 outputs the count number of the cam edge as the cam count number.

[0023] 1, input switching unit 52 receives crank timing from timer 22 and cam timing from timer 40. When the crank signal is normal, input switching unit 52 selects crank timing and outputs it to angle clock generation circuit 54, and when the crank signal is abnormal, input switching unit 52 selects cam timing and outputs it to angle clock generation circuit 54.

[0024] When crank timing is output from the input switching unit 52, the angle clock generation circuit 54 generates an angle clock having a period obtained by dividing the time interval between the current crank timing and the previous crank timing by a multiplier corresponding to the crank signal. When cam timing is output from the input switching unit 52, the angle clock generation circuit 54 generates an angle clock having a period obtained by dividing the time interval between the current cam timing and the previous cam timing by a multiplier corresponding to the cam timing.

[0025] Therefore, when the engine speed increases, the period of the angle clock becomes shorter, and when the engine speed decreases, the period of the angle clock becomes longer. For example, when the output of the input switching unit 52 is crank timing, the angle clock generation circuit 54 generates an angle clock with a period corresponding to 1° CA, which is the time interval of the crank timing divided by 10. When the output of the input switching unit 52 is cam timing, the angle clock generation circuit 54 generates an angle clock with a period corresponding to 1° CA, which is the time interval of the cam timing divided by 180.

[0026] The angle counter of the angle clock generation circuit 54 counts the number of clocks of the angle clock and outputs the count number. The angle timer 56 compares the count number of the angle counter output from the angle clock generation circuit 54 with a comparison value, which is the count number of the angle counter corresponding to 30° CA. When the count number of the angle counter matches the comparison value, the angle timer 56 outputs a match signal to the interrupt selection unit 60 as a pseudo interrupt request every 30° CA.

[0027] Furthermore, when the count number of the angle counter matches the comparison value, the angle timer 56 outputs the value of the free-run counter 20 at that time to the engine control unit 70 as the actual pseudo timing at which a pseudo event (described later) is executed every 30° CA. This generates the actual pseudo timing of the engine control executed between the current cam signal and the next cam signal.

[0028] The comparison value to be compared with the count number of the angle counter is set in a register or the like by the interrupt control unit 72. The interrupt selection unit 60 receives the interrupt requests in order from the earliest one among the cam interrupt requests every 180° CA output from the timer 40, the pseudo interrupt requests every 30° CA output from the angle timer 56, and the interrupt requests output from another microcomputer (not shown). The interrupt selection unit 60 outputs the received interrupt requests to the engine control unit 70.

[0029] The engine control unit 70 is mainly composed of a CPU and semiconductor memories such as RAM and ROM. The engine control unit 70 includes an interrupt control unit 72, an injector control unit 74, an ignition control unit 76, and the like, as functional components realized by the CPU executing programs stored in the semiconductor memory.

[0030] The interrupt control unit 72 executes a cam interrupt process, which will be described later, when a cam interrupt request is output from the interrupt selection unit 60 every 180° CA. The interrupt control unit 72 executes a pseudo interrupt process, which will be described later, when a pseudo interrupt request is output from the interrupt selection unit 60 every 30° CA, as a pseudo event.

[0031] When the pseudo-interrupt request is output from the interrupt selection unit 60, the injector control unit 74 executes injection control of the injector as a pseudo-event executed every 30° CA. When the pseudo-interrupt request is output from the interrupt selection unit 60, the ignition control unit 76 executes ignition control of fuel as a pseudo-event executed every 30° CA.

[0032] When the crank signal is normal, the injector control unit 74 and the ignition control unit 76 execute normal engine control in response to a pseudo interrupt request generated every 30° CA based on the crank signal.

[0033] When the crank signal is abnormal, the injector control unit 74 and the ignition control unit 76 execute an evacuation driving process to evacuate the vehicle to a safe place as engine control in response to a pseudo interrupt request generated every 30° CA based on the cam signal.

[0034] When the crank signal is abnormal, the interrupt control unit 72 calculates the theoretical timing of the aforementioned pseudo event that is executed every 30° CA based on the cam signal interval, which is the time interval corresponding to 180° CA calculated by the cam interrupt processing.

[0035] [1-2. Processing] (1) Cam interrupt processing The cam interrupt process executed by the microcomputer 10 will be described with reference to the flowchart of Fig. 3. The cam interrupt process shown in Fig. 3 is executed every 180° CA in accordance with the rotation of the camshaft when the interrupt selector 60 outputs a cam interrupt request.

[0036] In S400, the interrupt control unit 72 acquires the current cam timing from the timer 40 if the cam timings output by the timers 40 and 50 match. In S402, the interrupt control unit 72 calculates the time interval of the cam signal, which is the interval between the current cam timing and the previous cam timing, from the following equation (1).

[0037] Cam signal time interval = current cam timing - previous cam timing (1) The interrupt control unit 72 obtains the cam timing as the count number of the free-running counter 20, and therefore the time interval of the cam signal calculated by the formula (1) is calculated as the difference in the count number of the free-running counter 20.

[0038] In S404, the interrupt control unit 72 calculates the 1° CA time from the following equation (2): In this embodiment, the angle interval of the cam signal in equation (2) is 180° CA. 1° CA time = time interval of cam signal / angle interval of cam signal (2) If the angle clock generation circuit 54 is functioning normally, the 1° CA time calculated in S404 will match the period of the angle clock generated by the angle clock generation circuit 54 at the current cam edge.

[0039] In S406, the interrupt control unit 72 calculates the theoretical pseudo timing of the pseudo 30° CA to be executed after the cam timing of the currently detected cam edge using the following equation (3): The theoretical pseudo timing calculated using equation (3) is the theoretical timing of the actual pseudo timing that is estimated to be generated by the angle timer 56 based on the number of angle clock counts.

[0040] Theoretical pseudo timing = current cam timing + 1° CA time × offset angle up to pseudo 30° CA (3) In equation (3), the offset angle up to the pseudo 30° CA is the angle difference between the CA of the next pseudo event to be executed and the CA of the current cam edge.

[0041] In S408, the interrupt control unit 72 sets the comparison value, which is compared with the count number of the angle counter in the angle timer 56, to a value corresponding to the theoretical pseudo timing calculated in S406. As a result, when the count number of the angle counter matches the comparison value, a pseudo interrupt request for the next pseudo event of the current cam edge is output from the angle timer 56.

[0042] In S410, the interrupt control unit 72 sets the current cam timing as the previous cam timing. (2) Pseudo interrupt processing The pseudo-interrupt process executed by the microcomputer 10 every 30° CA will be described with reference to the flowchart of Fig. 4. The pseudo-interrupt process shown in Fig. 4 is executed when the interrupt selection unit 60 outputs a pseudo-interrupt request.

[0043] In S420, the interrupt control unit 72 obtains the actual pseudo timing from the angle timer 56. If the timer circuit 30 including the angle clock generation circuit 54 and the angle timer 56 is normal, the difference between the theoretical pseudo timing and the actual pseudo timing will be equal to or less than a predetermined value.

[0044] In S422, the interrupt control unit 72 calculates a predetermined value for determining the difference between the theoretical pseudo timing and the actual pseudo timing from the following equation (4): The predetermined value is a value obtained by converting a predetermined angle into a predetermined time.

[0045] Predetermined value = Predetermined angle x 1°CA time...(4) 5, if an abnormality in the timer circuit 30 causes the angle clock generation circuit 54 to malfunction and the count rate of the angle counter in the angle clock generation circuit 54 increases, the actual pseudo timing deviates from the theoretical pseudo timing, resulting in a timing difference. If the actual pseudo timing deviates from the theoretical pseudo timing, engine control such as injector control and ignition control cannot be performed at the appropriate timing.

[0046] An abnormality in the timer circuit 30 may also occur in the angle timer 56. In this case, the actual pseudo timing output from the angle timer 56 may also deviate from the theoretical pseudo timing.

[0047] In S424, the interrupt control unit 72 determines whether the difference between the theoretical pseudo timing and the actual pseudo timing is equal to or greater than a predetermined value. The theoretical pseudo timing compared with the actual pseudo timing in S424 is the value set in S406 of Fig. 3 or S434 of Fig. 4. If the determination in S424 is Yes, the interrupt control unit 72 proceeds to S428.

[0048] If the determination in S424 is No, in S426 the interrupt control unit 72 determines that the timer circuit 30 is normal, clears the abnormality counter, and moves the process to S434. In S428, the interrupt control unit 72 increments the abnormality counter that counts the number of provisional abnormalities in the timer circuit 30. In S430, the interrupt control unit 72 determines whether the value of the abnormality counter is equal to or greater than a predetermined number.

[0049] The abnormality counter is cleared when the determination in S424 is No. Therefore, the value of the abnormality counter reaches or exceeds the predetermined number of times when the determination in S424 is Yes for a predetermined number of consecutive times or more, that is, when the timer circuit 30 is determined to be temporarily abnormal for a predetermined number of consecutive times or more.

[0050] If the determination in S430 is No, the process proceeds to S434. If the determination in S430 is Yes, in S432, the interrupt control unit 72 determines that the timer circuit 30 is seriously abnormal, and ends this process. As a result, S434 and S436 are not executed, and the theoretical pseudo timing for starting the next pseudo event is not set, so engine control for running the vehicle, such as injector control and ignition control, and this process are not executed. As a result, the vehicle stops.

[0051] In S434, the interrupt control unit 72 calculates the next theoretical pseudo timing from the following equation (5): The 1° CA time used in equation (5) is the value calculated in S404 of Fig. 3. The theoretical pseudo timing calculated by equation (5) is a theoretical value of the actual pseudo timing that is estimated to be generated by the angle timer 56 based on the number of angle clock counts.

[0052] Theoretical pseudo timing = current theoretical pseudo timing + 1°CA time × 30°CA ···(5) In S436, the interrupt control unit 72 sets the count number of the angle counter corresponding to the theoretical pseudo timing calculated in S434 as a comparison value in the angle timer 56. This causes the next pseudo event to be started at the theoretical pseudo timing calculated in S434. After processing S436, this processing ends.

[0053] In the first embodiment described above, the microcomputer 10 corresponds to the engine control device, the timers 40 and 50 correspond to the cam timing detection unit, the angle clock generation circuit 54 and the angle timer 56 correspond to the actual pseudo timing generation unit, and the interrupt control unit 72 corresponds to the theoretical pseudo timing generation unit and the abnormality determination unit.

[0054] [1-3.Effects] According to the first embodiment described above, the following effects can be obtained. (1a) Abnormalities in the timer circuit 30, which includes the angle clock generation circuit 54 and the angle timer 56, can be determined using a single microcomputer 10, without duplicating the microcomputer 10 and comparing the outputs of the two timer circuits 30. This allows for inexpensive determination of abnormalities in the timer circuit 30.

[0055] (1b) If it is determined that the timer circuit 30 is abnormal, the next pseudo event is not initiated, so abnormal running of the vehicle can be suppressed and the vehicle can be stopped. (1c) If the timer circuit 30 is determined to be temporarily abnormal a predetermined number of times in succession, the timer circuit 30 is determined to be permanently abnormal, thereby preventing the timer circuit 30 from being mistakenly determined to be abnormal due to a temporary abnormality.

[0056] [2. Second Embodiment] [2-1. Differences from the first embodiment] The second embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference will be made to the preceding description.

[0057] In the first embodiment described above, whether or not the timer circuit 30 is abnormal is determined based on the difference between the theoretical pseudo timing and the actual pseudo timing. In contrast, in the second embodiment, whether or not the timer circuit 30 is abnormal is determined in consideration of changes in engine speed, which is different from the first embodiment.

[0058] [2-2. Processing] The pseudo-interrupt process of the second embodiment, which is executed by the microcomputer 10 every 30° CA, will be described with reference to the flowchart of Fig. 6 and the time chart of Fig. 7. The pseudo-interrupt process shown in Fig. 6 is executed every time a pseudo-event is started.

[0059] 3 of the first embodiment is also executed in the second embodiment. Also, the pseudo interrupt process of the first embodiment in FIG. 4 is executed according to the determination result in the pseudo interrupt process of FIG.

[0060] If the engine speed increases during evacuation travel in which engine control is performed based on the cam signal, the count speed of the angle counter increases, as shown in Figure 7. It is normal for the engine speed to increase and the count speed of the angle counter to increase during evacuation travel.

[0061] However, if the pseudo-interrupt processing of FIG. 4 of the first embodiment is executed without executing the pseudo-interrupt processing of FIG. 6, when the engine speed increases, there is a risk that the timer circuit 30 will be determined to be abnormal by the judgment of S424 of FIG. 4.

[0062] Even if the engine speed increases, if the determination in S424 in Fig. 4 is made based on the theoretical pseudo timing set based on the interval between the current cam timing and the previous cam timing, the determination in S424 will be No. In other words, the timer circuit 30 will not be determined to be abnormal.

[0063] However, the pseudo interrupt process, which is started by the actual pseudo timing generated by the timer circuit 30 based on the interval between the current cam timing and the previous cam timing, may be executed before the cam interrupt process executed by the current cam edge. This occurs, for example, when the current cam edge occurs, and the cam interrupt is masked for other interrupt processes, causing the cam interrupt process to wait.

[0064] In this case, as shown in FIG. 7, if the engine speed increases between the previous cam edge and the current cam edge, the execution interval of the actual pseudo timing generated by the timer circuit 30 becomes shorter than the execution interval generated based on the interval between the cam edge before the previous one and the previous cam edge.

[0065] On the other hand, if the current cam edge does not cause the cam interrupt process to be executed before the pseudo interrupt process, the theoretical pseudo timing remains the same as the theoretical pseudo timing generated based on the interval between the cam edge two before the previous one and the previous cam edge. In this case, the determination in S424 of FIG. 4 may be Yes, and the timer circuit 30 may be determined to be abnormal.

[0066] Therefore, in S440, the interrupt control unit 72 determines whether the current cam timing matches the latest cam timing obtained from the timers 40 and 50. The current cam timing is obtained in S400 in the cam interrupt process of FIG.

[0067] If the determination in S440 is Yes, this indicates that the cam interrupt process was executed when the current cam edge was detected and the current cam timing was updated to the latest value. In this case, the interrupt control unit 72 executes the pseudo-interrupt process of FIG. 4 described in the first embodiment.

[0068] If the determination in S440 is No, this indicates that the cam interrupt process was not being executed when the current cam edge was detected, and the current cam timing has not been updated to the latest value. In this case, the interrupt control unit 72 does not execute the pseudo-interrupt process of FIG. 4, and ends this process.

[0069] Then, the awaited cam interrupt process is executed, and the pseudo interrupt process in Fig. 4 is not executed until the latest cam timing and the current cam timing match, i.e., the abnormality determination process in S424 in Fig. 4 is not executed.

[0070] When the awaited cam interrupt process is executed, the determination in S424 in Fig. 4 is made based on the theoretical pseudo timing generated from the interval between the previous cam edge and the current cam edge, which is set according to the increase in engine speed. In this case, the determination in S424 is No.

[0071] [2-3. Effects] According to the second embodiment described above, in addition to the effects (1a) to (1c) of the first embodiment described above, the following effects can be obtained.

[0072] (2a) Even if the engine speed increases and the pseudo-interrupt process executed based on the actual pseudo timing generated from the interval between the previous cam edge and the current cam edge is executed before the cam interrupt process activated by the current cam edge, it is possible to prevent the system from determining that an abnormality has occurred.

[0073] 3. Third Embodiment [3-1. Differences from the second embodiment] The third embodiment has the same basic configuration as the second embodiment, and therefore the differences will be described below. Note that the same reference numerals as those in the second embodiment indicate the same configuration, and reference will be made to the preceding description.

[0074] In the second embodiment described above, the interrupt control unit 72 determined whether to execute the pseudo-interrupt processing of Figure 4 based on whether the latest cam timing obtained from the timers 40 and 50 matches the current cam timing.

[0075] In contrast, in the third embodiment, the interrupt control unit 72 differs from the second embodiment in that it determines whether to execute the pseudo-interrupt processing of Figure 4 based on whether the latest cam count number obtained from the timers 40 and 50 matches the current cam count number.

[0076] [3-2. Processing] (1) Cam interrupt processing In the cam interrupt process shown in FIG. 8 executed by the microcomputer 10, steps S450 and S454 to S462 are substantially the same as steps S400 to S410 in FIG. 3, and therefore a description thereof will be omitted. The cam interrupt process shown in FIG. 8 is executed every 180° CA in accordance with the rotation of the camshaft when the interrupt selector 60 outputs a cam interrupt request.

[0077] In S452, the interrupt control unit 72 obtains the cam count number of the current cam edge from the timer 40 if the cam count numbers output by the timers 40 and 50 match. In S464, the microcomputer 10 sets the current cam count number as the previous cam count number, and ends this process.

[0078] (2) Pseudo interrupt processing 9, the interrupt control unit 72 determines whether the latest cam count number obtained from the timers 40 and 50 matches the current cam count number. The current cam count number is obtained in S452 in the cam interrupt processing in FIG.

[0079] If the determination in S470 is Yes, this means that the cam interrupt process was executed when the current cam edge was detected, and the current cam timing and current cam count were updated to the latest values. In this case, the interrupt control unit 72 executes the pseudo-interrupt process of FIG. 4 described in the first embodiment.

[0080] If the determination in S470 is No, this means that the execution of the cam interrupt process is delayed due to another interrupt process when the current cam edge is detected, and the current cam timing and current cam count number have not been updated to the latest values, as shown in Figure 10. In this case, the interrupt control unit 72 does not execute the pseudo-interrupt process of Figure 4, and ends this process.

[0081] Then, the awaited cam interrupt process is executed, and the pseudo interrupt process in Fig. 4 is not executed until the latest cam count number and the current cam count number match, i.e., the abnormality determination process in S424 in Fig. 4 is not executed.

[0082] When the awaited cam interrupt process is executed, the determination in S424 in Fig. 4 is made based on the theoretical pseudo timing generated from the interval between the previous cam edge and the current cam edge, which is set according to the increase in engine speed. In this case, the determination in S424 is No.

[0083] In the third embodiment described above, the timers 40 and 50 correspond to the cam count measurement unit. [3-3. Effects] According to the third embodiment described above, it is possible to obtain the same effects as those of the second embodiment described above.

[0084] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modifications.

[0085] (4a) In the above-described embodiment, the crank signal has an angular interval of 10° CA and the cam signal has an angular interval of 180° CA, but this is not limited to this. Furthermore, the crank signal angular interval of 10° CA is divided by 10, and the cam signal angular interval of 180° CA is divided by 180 to generate angular clocks each having a period of 1° CA, but this is not limited to this. The angular interval of the angle clock is set appropriately depending on the required performance.

[0086] (4b) The microcomputer 10 and the methods described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the microcomputer 10 and the methods described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the microcomputer 10 and the methods described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. The methods for implementing the functions of each unit included in the microcomputer 10 do not necessarily need to include software; all of the functions may be implemented using one or more hardware components.

[0087] (4c) Multiple functions of one component in the above-described embodiments may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above-described embodiments may be omitted. Also, at least part of the configuration of the above-described embodiments may be added to or substituted for the configuration of another of the above-described embodiments.

[0088] (4d) In addition to the engine control device whose functions are realized by the aforementioned microcomputer 10, the present disclosure can also be realized in various forms, such as a system having the engine control device as a component, a program for causing a computer to function as the engine control device, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and an engine control method. [Explanation of symbols]

[0089] 10: Microcomputer (engine control device), 40, 50: Timer (cam timing detection unit, cam count measurement unit), 54: Angle clock generation circuit (actual pseudo timing generation unit), 56: Angle timer (actual pseudo timing generation unit), 72: Interrupt control unit (theoretical pseudo timing generation unit, abnormality determination unit)

Claims

1. an actual pseudo timing generating unit (54, 56) configured to generate an angle clock having a period obtained by dividing the interval between the current cam signal and the previous cam signal by a preset multiplication factor when a crank signal generated at a predetermined crank angle interval in response to the rotation of a camshaft of an engine is abnormal and, when the current cam signal is detected based on the cam signal generated at the predetermined cam angle interval in response to the rotation of the camshaft, generate an actual pseudo timing of engine control executed between the current cam signal and the next cam signal based on the count number of the angle clock; a theoretical pseudo timing generation unit (72, S400 to S410, S434) configured to generate theoretical pseudo timing of the actual pseudo timing that is estimated to be generated by the actual pseudo timing generation unit based on the count number of the angle clock in a cam interrupt process that is executed when the cam signal is detected, based on an interval between the current cam signal and the previous cam signal; an abnormality determination unit (72, S420 to S432, S440, S470) configured to determine that the actual pseudo timing generation unit is abnormal when a difference between the actual pseudo timing and the theoretical pseudo timing generated by the theoretical pseudo timing generation unit is equal to or greater than a predetermined value in a pseudo interrupt process started by the actual pseudo timing generated by the actual pseudo timing generation unit; An engine control device comprising:

2. 2. The engine control device according to claim 1, The abnormality determination unit (S440, S470) is configured not to determine that the actual pseudo timing generation unit is abnormal if the pseudo interrupt process, which is started at the actual pseudo timing generated by the actual pseudo timing generation unit when the current cam signal is detected, is executed before the cam interrupt process, which is executed when the current cam signal is detected. Engine control device.

3. 3. The engine control device according to claim 2, Further provided is a cam timing detection unit (40, 50) configured to detect the cam timing at which the cam signal is generated, the theoretical pseudo timing generating unit (S400) is configured to set the cam timing currently detected by the cam timing detecting unit as the current cam timing in the cam interrupt processing, The abnormality determination unit (S440) is configured not to determine that the actual pseudo timing generation unit is abnormal when the latest cam timing detected by the cam timing detection unit does not match the current cam timing set by the theoretical pseudo timing generation unit in the cam interruption processing in the pseudo interruption processing. Engine control device.

4. 3. The engine control device according to claim 2, The vehicle further includes a cam count measuring unit (40, 50) configured to measure the cam count number of the cam signal every time the cam signal is generated, the theoretical pseudo timing generating unit (S452) is configured to set the cam count number currently measured by the cam count measuring unit as the current cam count number in the cam interrupt processing, The abnormality determination unit (S470) is configured not to determine that the actual pseudo timing generation unit is abnormal if the latest cam count number measured by the cam count measurement unit does not match the current cam count number set by the theoretical pseudo timing generation unit in the cam interruption process in the pseudo interruption process. Engine control device.

5. 5. The engine control device according to claim 1, The abnormality determination unit (S430, S432) is configured to determine that the actual pseudo timing generation unit is abnormal when the actual pseudo timing generation unit is determined to be temporarily abnormal a predetermined number of times in succession. Engine control device.

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