JP5962441B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device that monitors whether or not a predetermined event repeatedly occurs.

  2. Description of the Related Art Conventionally, a technique for monitoring the operation of an electronic control device by another electronic control device is known. For example, in Patent Document 1, a monitoring program is started every predetermined cycle by a first microcomputer, and the monitoring program periodically monitors whether the second microcomputer to be monitored is operating normally. ing. In this way, if the monitoring program is started at every predetermined cycle, it can be monitored by the monitoring program whether or not a predetermined event repeatedly occurs in a device to be monitored.

Japanese Patent Laid-Open No. 2002-227661

  However, if the monitoring program is activated at a predetermined cycle regardless of whether a predetermined event has occurred, it is necessary to interrupt the execution of processes other than the monitoring process and execute the monitoring program. There is a problem that the load increases.

  The present invention has been made to solve the above-described problem, and an object thereof is to reduce the processing load of an electronic control device that monitors whether or not a predetermined event repeatedly occurs.

  According to the electronic control device of the present invention, when the measurement value by the timer that measures time by increasing or decreasing reaches a predetermined value, the notification unit outputs a notification signal to notify that the measurement value has reached the predetermined value. . The signal detection unit initializes the measurement value by the timer when the occurrence of the predetermined event is detected before the measurement value by the timer reaches the predetermined value based on the state signal indicating the occurrence state of the predetermined event that occurs repeatedly. If the occurrence of a predetermined event is not detected, the measurement value by the timer is not initialized.

  According to this configuration, when a predetermined event occurs before the measurement value by the timer reaches the predetermined value, the measurement value by the timer is initialized, and thus the measurement value does not reach the predetermined value. As a result, the notification signal is not output from the notification unit. On the other hand, if a predetermined event does not occur, the measured value by the timer is not initialized and reaches a predetermined value. As a result, the notification unit outputs a notification signal to notify that the measured value by the timer has reached a predetermined value.

As a result, it is not necessary to periodically start and execute the monitoring program in order to monitor whether or not a predetermined event repeatedly occurs, so that the processing load on the electronic control device is reduced.
Then, when a notification signal is output from the notification unit, a process set when a predetermined event does not occur may be executed.

The block diagram which shows the electronic controller by 1st Embodiment. The time chart which shows a monitoring process. The time chart which shows the monitoring process by a comparative example. The block diagram which shows the electronic control apparatus by 2nd Embodiment. The block diagram which shows the electronic control apparatus by 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
An electronic control unit (ECU) 10 shown in FIG. 1 executes engine control such as injection control of an injector 2 and discharge control of a fuel injection pump (not shown) in a vehicle equipped with, for example, a diesel engine. The microcomputer 20 is mainly composed of a microcomputer (hereinafter also referred to as “microcomputer”) 20 and an ASIC (Application Specific Integrated Circuit) 60.

  The microcomputer 20 is mainly composed of a hardware processing unit 30 and a software processing unit 50. The hardware processing unit 30 includes a pulse signal circuit 32, a timer unit 34, an edge detection unit 40, an abnormal signal output unit 42, and the like, and is a processing unit whose processing function is specified by a hardware configuration such as a circuit. is there.

  The pulse signal circuit 32 outputs a drive circuit control signal (S1) to the injector drive circuit 62 of the ASIC 60 in response to a command from the main process of the software processing unit 50. The drive circuit control signal is a pulse signal and defines the injection amount and injection timing of the injector 2.

  The timer unit 34 compares a predetermined value set in advance with a measured value by the timer 36, and outputs a notification signal when the measured value by the timer 36 reaches a predetermined value. The timer 36 may be a timer that monotonously increases by +1 in synchronization with the clock signal set to an appropriate frequency, or may be a timer that monotonously decreases by −1 in synchronization with the clock signal. .

  The edge detection unit 40 receives a state signal representing the injection state of the injector 2 from the ASIC 60, and when detecting that the injection has stopped, the edge detection unit 40 initializes the measurement value by the timer 36 to 0, for example. The status signal will be described later.

When the timer unit 34 outputs a notification signal, the abnormal signal output unit 42 outputs an emergency stop signal that instructs the injection of the injector 2 to be forcibly stopped.
The software processing unit 50 is a processing unit in which a processing function is specified by a CPU executing a program stored in a storage unit such as a ROM or a flash memory (not shown). The main processing of the software processing unit 50 executes injection control of the injector 2 and discharge control of the fuel injection pump.

  The software processing unit 50 generates an interrupt in response to a notification signal output from the timer unit 34 of the hardware processing unit 30, interrupts the main process, and executes an interrupt process. The software processing unit 50 returns to the interrupted main process when the abnormal process is terminated as the interrupt process.

The ASIC 60 is mainly composed of an injector drive circuit 62, a voltage value monitoring circuit 64, and a state signal generation circuit 66.
The injector drive circuit 62 is a drive circuit control signal (S1) output from the microcomputer 20.
Based on the above, an injection control signal (S2) is output to the injector 2. The injection control signal (S2) controls, for example, the driving voltage applied to the injector 2 by switching the transistor on and off.

The voltage value monitoring circuit 64 monitors the voltage value of the drive voltage applied to the injector 2 according to the injection control signal and outputs it to the state signal generation circuit 66.
The state signal generation circuit 66 converts the voltage value acquired from the voltage value monitoring circuit 64 into a pulse signal based on a predetermined threshold value, and generates and outputs a state signal indicating injection and stop of the injector 2.

(Monitoring process)
Next, monitoring is performed to monitor whether or not a predetermined event repeatedly occurs, with the predetermined event being the stop of injection according to the command of the drive control signal (S1) from the state in which the injector 2 is injecting fuel. The processing will be described based on the time chart of FIG.

  As described above, the hardware processing unit 30 of the microcomputer 20 outputs the drive circuit control signal (S1) from the pulse signal circuit 32 to the ASIC 60 in order to control the fuel injection of the injector 2. When the drive circuit control signal (S1) falls and the stop of fuel injection from the injector 2 is commanded, the timer unit 34 starts measurement by the timer 36 set to an initial value.

When the injection control signal ( S2 ) output from the injector drive circuit 62 is turned on based on the drive circuit control signal (S1), the energy charged in the capacitor (not shown) is released and applied to the injector 2. When the voltage value of the drive voltage applied to the injector 2 rises above a predetermined threshold value, fuel is injected from the injector 2.

  When the injection control signal (S2) is turned off, energization from the capacitor (not shown) to the injector 2 is stopped. And if the voltage value of the drive voltage applied to the injector 2 falls below a predetermined threshold value, the fuel injection from the injector 2 stops.

The voltage value monitoring circuit 64 acquires the voltage value (S3) applied to the injector 2 and outputs it to the state signal generation circuit 66.
The state signal generation circuit 66 compares the voltage value (S3) applied to the injector 2 with a predetermined threshold value, and falls when the voltage value (S3) rises above the threshold value and the injector 2 starts fuel injection. When the value (S3) falls below the threshold value and fuel injection stops, a state signal (S4) that rises is generated.

When the edge detection unit 40 detects the rising edge of the state signal (S4), the edge detection unit 40 outputs an initialization signal to the timer unit 34.
As described above, the timer 36 starts measurement at the timing when the drive circuit control signal (S1) falls and the stop of fuel injection from the injector 2 is commanded. When the initialization signal is output from the edge detection unit 40 before the measurement value reaches the predetermined value, the timer unit 34 stops the measurement by the timer 36 and initializes the measurement value to 0, for example.

  If the initialization signal is not output from the edge detection unit 40 before the measured value by the timer 36 reaches the predetermined value, and the measured value by the timer 36 reaches the predetermined value, the timer unit 34 indicates that the measured value by the timer 36 is the predetermined value. A notification signal for notifying that the value has been reached is output.

When the notification signal is output from the timer unit 34, the abnormal signal output unit 42 outputs an emergency stop signal (S5) to the injector drive circuit 62 of the ASIC 60.
When the emergency stop signal (S5) is output from the abnormal-time signal output unit 42, the injector drive circuit 62 performs a process such as forcibly stopping the energization of the injector 2 that is abnormal in injection, For the injector 2, an abnormal time process such as limiting the injection amount or stopping the fuel injection from a part of the injectors 2 and performing a reduced-cylinder operation is performed.

  In the software processing unit 50, when a notification signal is output from the timer unit 34, an abnormal time process corresponding to an abnormality in which the fuel injection of the injector 2 is not stopped and the fuel injection is continued is executed as an interrupt process.

  As the abnormal process executed by the software processing unit 50, for example, the discharge amount of the fuel injection pump is limited, or the ECU 2 other than the ECU 10 that controls the engine is notified of the injection abnormality of the injector 2 through communication such as CAN. It is possible. When the abnormal process is terminated, the software processing unit 50 returns to the interrupted main process.

  Here, the comparative example shown in FIG. 3 will be compared with the first embodiment. In the comparative example, unlike the first embodiment, the edge detection unit 40 turns on the edge detection signal instead of initializing the measurement value by the timer 36 at the time of normal detection of the rising edge of the state signal (S4). . When the edge detection unit 40 does not detect the rising edge of the state signal (S4), the edge detection signal remains off.

  In the comparative example, even if the injector 2 normally stops fuel injection before the measured value by the timer 36 reaches a predetermined value, the measured value by the timer 36 is detected even if the edge detector 40 detects the rising edge of the state signal (S4). Is not initialized, an interrupt is generated in the software processing unit 50 every time the measured value by the timer 36 reaches a predetermined value. When the interruption occurs, the software processing unit 50 interrupts the main process and executes the monitoring process.

  In the monitoring process of the comparative example, when the edge detection unit 40 detects the rising edge of the state signal and the edge detection signal is ON, the software processing unit 50 determines that the fuel injection has stopped normally, and the measured value by the timer 36 is obtained. Initialization is performed, the edge detection signal is turned off, and the process returns to the main process.

  On the other hand, in the monitoring process of the comparative example, when the edge detection unit 40 does not detect the rising edge of the state signal and the edge detection signal is OFF, the software processing unit 50 determines that the fuel injection has not stopped normally. In this case, the software processing unit 50 outputs an emergency stop signal (S5) to the injector drive circuit 62, and executes the abnormality processing of the first embodiment described above.

  Thus, in the comparative example, every time the measured value by the timer 36 reaches a predetermined value, an interrupt is generated in the software processing unit 50 and the monitoring process is executed, so that the processing load on the ECU 10 increases. Furthermore, since the main process of the software processing unit 50 is interrupted every time an interrupt occurs, the execution of the main process is hindered.

  In the first embodiment, only when the initialization signal is not output from the edge detection unit 40 before the measured value by the timer 36 reaches a predetermined value because of an injection abnormality that does not stop the fuel injection in the injector 2, software processing is performed. An interrupt occurs in the unit 50. Therefore, the processing load of the ECU 10 as a whole is reduced. Further, since the main process is not interrupted while the fuel injection of the injector 2 is normal, the processing amount of the main process increases as compared with the comparative example.

  When the edge detection unit 40 of the hardware processing unit 30 detects an abnormality in fuel injection from the state signal, the emergency stop signal of the injector 2 is output from the abnormality signal output unit 42 of the hardware processing unit 30. Only the circuit configuration of the processing unit 30 can quickly stop the fuel injection of the injector 2 with an abnormal injection.

[Second and Third Embodiments]
The ECU 12 of the second embodiment shown in FIG. 4 includes a pulse signal circuit 32, a timer unit 34, an edge detection unit 40, an abnormal signal output unit 42, a software processing unit 50, an injector drive circuit 62, a voltage value monitoring circuit 64, and a state. Of the components constituting the ECU 12 such as the signal generation circuit 66, only the software processor 50 is constituted by the microcomputer 70. The other components other than the software processing unit 50 are configured by one ASIC 80.

  According to this configuration, since the microcomputer 70 can be configured by only the software processing unit 50 that executes the main processing and the interrupt processing described in the first embodiment, a general-purpose microcomputer can be used.

  The configuration of the second embodiment other than the configuration unit other than the software processing unit 50 configured by one ASIC 80 is substantially the same as that of the first embodiment. The same reference numerals are given. Therefore, the same effect as in the first embodiment is also produced in the second embodiment.

  The ECU 14 of the third embodiment shown in FIG. 5 is obtained by realizing the configurations of the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 4 with a single integrated circuit. Thereby, ECU14 can be reduced in size.

  The configuration of the third embodiment except that the ECU 14 is realized by one integrated circuit is substantially the same as that of the first embodiment, and the same components are denoted by the same reference numerals as those of the first embodiment. Therefore, the same effect as that of the first embodiment also occurs in the third embodiment.

[Other Embodiments]
In the above embodiment, when the measured value measured by the timer 36 reaches a predetermined value, the notification signal is output from the timer unit 34 to the software processing unit 50, and the injector drive circuit 62 is output from the abnormal time signal output unit 42 based on the notification signal. An emergency stop signal for stopping the fuel injection of the injector 2 was output. On the other hand, only one of the notification signal for the software processing unit 50 or the emergency stop signal for the injector 2 for the injector drive circuit 62 may be output.

  When the notification signal is output only to the software processing unit 50, an emergency stop signal for stopping the fuel injection of the injector 2 may be output to the injector drive circuit 62 in the interrupt processing of the software processing unit 50.

  The electronic control device of the present invention includes at least a timer unit 34 and an edge detection unit 40. When the edge detection unit 40 detects that a predetermined event does not occur and the timer 36 is not initialized, the timer 36 It is sufficient that the timer unit 34 can notify that the measurement value to be measured has reached a predetermined value by the notification signal. The notification signal output from the timer unit 34 may be used in any way.

  Therefore, for example, only the timer unit 34 and the edge detection unit 40, only the microcomputer 20 of the first embodiment, or any of the ECUs 10, 12, and 14 may be used as the electronic control device of the present invention. Each electronic control device of the present invention may be realized by an integrated circuit.

In the present invention, the circuit constituting the ASIC 60 of the first embodiment or the ASIC 80 of the second embodiment may be configured as an individual circuit instead of a single ASIC.
Further, even if the edge detection unit 40 detects a fall instead of a rise and outputs an initialization signal with respect to the state signal (S4), even if the injector 2 monitors an abnormality that does not cause the fuel injection to stop while monitoring Good.

  Further, as a signal detection unit for detecting whether or not a predetermined event has occurred based on the state signal, instead of the edge detection unit 40 for detecting the rising or falling of the state signal, it is based on the level of the state signal. A signal detector that detects whether or not a predetermined event has occurred may be used.

  In the above embodiment, an example in which the present invention is applied to an electronic control device that executes engine control of a diesel engine vehicle has been described. In addition to this, the present invention may be applied to an electronic control device for a vehicle using a gasoline engine vehicle or other fuel. The present invention is not limited to an electronic control device mounted on a vehicle, and may be applied to an electronic control device used in any field as long as it is monitored whether a predetermined event has repeatedly occurred.

  As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

2: injector (control target), 10, 12, 14: ECU (electronic control device), 20: microcomputer (electronic control device), 30: hardware processing unit (electronic control device), 34: timer unit (notification unit) , 36: timer, 40: edge detection unit (signal detection unit), 50: software processing unit, 60, 80: ASIC, 62: injector drive circuit (control unit), 66: status signal generation unit

Claims (6)

A timer (36) that starts increasing or decreasing each time the occurrence of a predetermined event is commanded by a control signal and measures the time;
When the measurement value measured by the timer reaches a predetermined value, a notification unit (34) for outputting and notifying that the measurement value has reached the predetermined value;
Based on the state signal representing the state of occurrence of said predetermined event repeatedly occurs, the measured value by the timer to detect the occurrence of the predetermined event before the measurement value reaches the predetermined value is initialized, the predetermined A signal detection unit (40) that does not initialize the measurement value by the timer unless the occurrence of the event is detected,
An electronic control device (10, 12, 14, 20, 30) comprising: The electronic control device according to claim 1,
A control unit (62) for controlling the controlled object;
A state signal generation unit (66) for generating the state signal representing the occurrence state of the predetermined event in the controlled object, based on an operating signal representing the operating state of the controlled object;
Further comprising
When the notification unit outputs the notification signal, the control unit performs control that is set when the predetermined event does not occur before the measurement value reaches the predetermined value on the control target. ,
An electronic control device (10, 12, 14) characterized by that. The electronic control device according to claim 1 or 2,
A software process that generates an interrupt when the notification unit outputs the notification signal, and executes an interrupt process that is set when the predetermined event does not occur before the measured value reaches the predetermined value A part (50),
An electronic control device (10, 12, 14, 20) characterized by that. The electronic control device according to claim 3,
Of the constituent parts (32, 34, 40, 42, 50, 62, 64, 66) constituting the electronic control device according to claim 3, the software processing part is constituted by a microcomputer (70).
An electronic control device (12) characterized by the above. The electronic control device according to claim 4,
The other configuration units (32, 34, 40, 42, 62, 64, 66) other than the software processing unit are configured by an ASIC (80).
An electronic control device (12) characterized by the above. The electronic control device according to any one of claims 1 to 3,
Composed of integrated circuits,
An electronic control device (14) characterized by the above.

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