JP2008190389A - Electronic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a deceleration shock or the like of a vehicle when an anomaly occurs, in relation to a device 1 for controlling the drive of a throttle valve, and inhibiting the drive of the throttle valve when the anomaly occurs. <P>SOLUTION: When an anomaly is detected by a device 5, a device 9 calculates a predetermined deceleration period based on a vehicle speed before the anomaly occurs stored in a device 7, and a generator 11 outputs a signal set high only in a calculated deceleration period to a switch (SW) 25. A pulse signal is inputted to a terminal (a) of the SW 25 from a device 15. A high signal outputted from a SW 23 when the anomaly occurs is inputted to a terminal (b) from the SW 23. The SW 25 outputs a pulse signal from the device 15 to a driver 80 as a block/feed signal representing inhibition when high, and permission when low by connecting it to the terminal (a) side only while the signal from the generator 11 is high. Thereby, the drive of a motor 82 is intermittently inhibited, and a vehicle speed is gently reduced by gradually closing the throttle valve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic control device that controls driving of a throttle valve of a vehicle.

  Conventionally, in a vehicle, an electronic control unit (hereinafter referred to as an ECU) detects an accelerator operation amount from a signal from an accelerator sensor, determines a target throttle opening according to the detected accelerator operation amount, An actuator for driving the throttle valve is controlled so that the opening degree matches the target throttle opening degree.

  In this type of throttle control system for controlling the driving of the throttle valve, the opening of the throttle valve is detected by a throttle sensor, and whether or not there is an abnormality is determined based on the detected opening of the throttle valve. For example, when the detected opening of the throttle valve differs from the target throttle opening by a predetermined value or more, it is determined that the throttle valve is not normally driven, that is, abnormal.

  Conventionally, when an abnormality is detected in the throttle control system, the ECU prohibits control of an actuator for driving the throttle valve. This is a so-called fail-safe function for preventing overrun of the vehicle. That is, when the control of the actuator is prohibited, the throttle valve returns to the initial position by the biasing force in the closing direction by the return spring. Here, the throttle valve also receives an urging force from the retracting travel spring in the opening direction, and the initial position is balanced by the urging force of the return spring and the urging force of the retracting travel spring. It is a position that is opened by a predetermined angle.

  On the other hand, if the control of the actuator is prohibited when an abnormality is detected in the throttle control system as described above, the intake air amount of the engine is suddenly reduced to cause a large deceleration shock or an engine stall, which is not preferable.

Therefore, in Patent Document 1, for example, when an abnormality is detected in the throttle control system, the fuel injection to the engine by the injector is intermittently cut so that the engine speed is equal to or less than a certain reference speed. I try to avoid shocks and engine stalls.
JP-A-6-330799

  However, even if the technique of Patent Document 1 is used, when an abnormality occurs in the fuel injection control system that controls fuel injection by the injector, fuel injection to the engine cannot be cut intermittently. It becomes impossible to avoid deceleration shock and engine stall when an abnormality occurs in the throttle control system.

  The present invention has been made in view of these problems, and provides a technique capable of using a conventional fail-safe function and avoiding a deceleration shock and an engine stall in an electronic control device that controls the driving of a throttle valve. For the purpose.

  In order to achieve the above object, an electronic control apparatus according to claim 1, wherein an abnormality of a throttle control system including a throttle drive means for driving a throttle valve provided in an intake system of an internal combustion engine and at least the throttle drive means is provided. An electronic control device is provided with an abnormality detecting means for detecting the presence or absence of the engine and a fail safe means for prohibiting the operation of the throttle driving means when at least an abnormality of the throttle control system is detected by the abnormality detecting means.

In particular, the fail-safe means intermittently prohibits the operation of the throttle drive means.
That is, in the electronic control device according to the first aspect, when an abnormality occurs in the throttle control system, the prohibition / permission of the operation of the throttle driving means is repeated. As an abnormality of the throttle control system, for example, an abnormality of a motor for driving the throttle valve, an abnormality of a driver for controlling the driving of the motor, a sensor for detecting the opening of the throttle valve, or an accelerator pedal There is an abnormality in the sensor that detects the operation amount.

  When the operation of the throttle driving means is prohibited, the throttle driving means cannot drive the throttle valve. For this reason, the throttle valve is moved to the initial position (as described in the background art section) by the urging force of the return spring. It tries to return to the position opened by an angle. On the other hand, when the operation of the throttle driving means is permitted, the throttle driving means can drive the throttle valve, and the throttle valve tries to open to a predetermined opening degree, for example, under the control of the throttle driving means.

  For this reason, the throttle valve repeats, for example, an operation of closing → opening → closing. Therefore, compared with the case where the throttle valve is immediately closed, the air amount to the internal combustion engine gradually decreases, and therefore the engine speed gradually decreases. Accordingly, the speed of the vehicle on which the internal combustion engine is mounted gradually decreases, and a sudden deceleration shock and engine stall can be avoided.

  By the way, for example, as the vehicle speed increases, the deceleration shock can be reduced by extending the period for decelerating the vehicle speed. Conversely, as the vehicle speed decreases, the period for decelerating the vehicle speed can be reduced.

  Accordingly, an electronic control device according to a second aspect is the electronic control device according to the first aspect, wherein the state detection means for detecting the number of revolutions of the internal combustion engine or the vehicle speed of the vehicle on which the internal combustion engine is mounted as a detection target, and abnormality detection Period calculating means for calculating a period during which the fail safe means intermittently prohibits the operation of the throttle driving means based on the detection result detected by the state detecting means immediately before the abnormality of the throttle control system is detected by the means. ing.

The fail-safe means intermittently prohibits the operation of the throttle driving means during the period calculated by the period calculating means.
The period calculating means includes, for example, a means for calculating a period with reference to a map stored in advance or calculating a period by a predetermined calculation.

  According to the electronic control device of the second aspect, for example, when the rotational speed of the internal combustion engine before the occurrence of an abnormality (immediately before) is a predetermined number or higher (high speed), or when the vehicle speed is a predetermined speed or higher (high speed). If the speed of the internal combustion engine before the occurrence of an abnormality (immediately before) is less than a predetermined number (low speed), or if the vehicle speed is When the speed is lower than a certain speed (low speed), the period during which the operation of the throttle driving means is intermittently prohibited can be reduced.

  Therefore, regardless of whether the rotational speed of the internal combustion engine before the abnormality occurs is high or low, the rotational speed of the internal combustion engine can be gradually decreased. Regardless of whether the vehicle speed before the occurrence is high or low, the vehicle speed can be gradually reduced.

  Next, an electronic control device according to a third aspect is the electronic control device according to the first and second aspects, wherein the throttle drive means supplies operating power to an actuator for adjusting the opening of the throttle valve, The fail-safe means intermittently prohibits the operation of the throttle drive means supplying operating power to the actuator.

  According to such an electronic control device of the third aspect, not all the operation of the throttle driving means is prohibited, but only the operation in which the throttle driving means supplies the operating power to the actuator is intermittently prohibited. In other words, since only the minimum operation of the operation of the throttle driving means is intermittently prohibited, it is possible to obtain the effect as described above, that is, the effect of avoiding the deceleration shock and the engine stall with a simpler configuration. it can.

  Further, since only the minimum operation is prohibited, when the operation of the throttle driving means is permitted, the throttle driving means can quickly drive the throttle valve, and the throttle valve does not drive at a desired timing. The occurrence of such inconveniences can be prevented. For this reason, the rotational speed of the internal combustion engine or the vehicle speed of the vehicle on which the internal combustion engine is mounted can be reduced more smoothly.

  According to a fourth aspect of the present invention, there is provided an electronic control device according to the first aspect, further comprising: a state detection unit that detects the number of revolutions of the internal combustion engine or the vehicle speed of the vehicle on which the internal combustion engine is mounted as a detection target. Yes.

  The fail-safe means sets a target value to be detected when an abnormality in the throttle control system is detected by the abnormality detection means so that the detection result detected by the state detection means becomes the set target value. The operation of the throttle driving means is intermittently prohibited. Further, the target value is changed to a small value step by step.

  In the electronic control device according to the fourth aspect, the operation of the throttle driving means is not merely prohibited intermittently, but the actual detection result (the rotational speed, the vehicle speed) is set to the set target value. The operation of the throttle drive means is intermittently prohibited. In this case, more specifically, feedback control may be performed. That is, the ratio of the time for prohibiting the operation of the throttle driving means per unit time may be changed one by one so that the actual detection result becomes the set target value.

  Furthermore, in claim 4, since the fail safe means is adapted to change the target value to a small value in a stepwise manner, it is possible to prevent a sudden decrease in the rotational speed or the vehicle speed of the internal combustion engine. . Therefore, the rotational speed of the internal combustion engine or the vehicle speed can be gradually reduced more reliably.

  Next, the electronic control device according to claim 5 is the electronic control device according to claim 2 or 3, wherein the fail safe means sets a target value to be detected when an abnormality of the throttle control system is detected by the abnormality detection means. The operation of the throttle drive means is intermittently prohibited during the period calculated by the period calculation means so that the detection result detected by the state detection means becomes the set target value. The target value is changed to a small value step by step.

  In this electronic control device according to claim 5, the operation of the throttle drive means is intermittently prohibited especially during the period calculated by the period calculation means. According to this claim 5, claim 4 is described. The same effect can be obtained.

  Next, an electronic control device according to a sixth aspect is the electronic control device according to any one of the first to fifth aspects, wherein a signal (hereinafter referred to as a brake operation signal) indicating an operation state of a brake pedal provided in a vehicle on which the internal combustion engine is mounted. The fail-safe means determines whether or not the brake pedal has been operated based on the brake operation signal when the abnormality detection means detects an abnormality in the throttle control system, and the brake pedal When it is determined that is operated, the operation of the throttle driving means is continuously prohibited.

  According to such an electronic control device of the sixth aspect, when an abnormality occurs in the throttle control system, the operation of the throttle driving means is continuously prohibited when the brake pedal is operated. Yes. That is, the brake pedal operation by the driver, in other words, the intention of the driver is reflected. For this reason, the intention of the driver matches the behavior of the vehicle. Therefore, vehicle control that does not give the driver a sense of incongruity can be realized.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
First, FIG. 1 is a schematic configuration diagram of an engine control system, and this system includes an electronic control device (hereinafter referred to as a throttle ECU) 1 for throttle control to which the present invention is applied.

An engine 10 as an internal combustion engine mounted on a vehicle includes an intake passage 12 constituting an intake system. A throttle valve 90 is disposed in the intake passage 12.
The throttle valve 90 is always urged in the closing direction by a return spring (not shown). On the other hand, it is always urged in the opening direction by a retreat travel spring (not shown). Hereinafter, a position where the urging force of the return spring and the urging force of the retreat travel spring are balanced and the throttle valve 90 is opened by a predetermined angle is referred to as an initial position of the throttle valve 90.

  The throttle valve 90 is opened and closed by driving a motor 82 (for example, a servo motor) as an actuator provided in the vicinity thereof, and a support shaft of the throttle valve 90 is connected to an output shaft of the motor 82.

  The driver 80 outputs a drive signal to the motor 82 in accordance with an instruction from the throttle ECU 1 to control the drive of the motor 82. Specifically, the driver 80 controls the direction of rotation and the amount of rotation of the output shaft of the motor 82 by controlling the energization direction and the amount of power to a coil (not shown) of the motor 82.

  A throttle position sensor 92 for detecting the opening degree of the throttle valve 90 is provided in the vicinity of the throttle valve 90. A signal from the throttle position sensor 92, that is, a signal indicating the opening of the throttle valve 90 (hereinafter referred to as a throttle sensor signal) is input to the throttle ECU 1.

  The accelerator operation amount detector 31 detects the operation amount of the accelerator pedal 32 of the vehicle. For example, an accelerator pedal sensor 33 (see FIG. 2) for detecting an operation amount of the accelerator pedal 32 corresponds to the accelerator operation amount detection unit 31. A detection signal indicating the amount of operation of the accelerator pedal 32 (hereinafter referred to as an accelerator position signal) is input to the throttle ECU 1.

  The vehicle speed detection unit 41 detects the speed of the vehicle on which the engine 10 is mounted. For example, a vehicle speed sensor (not shown) corresponds to the vehicle speed detection unit 41. Then, a detection signal indicating the vehicle speed (hereinafter referred to as a vehicle speed signal) is input to the throttle ECU 1.

  The engine speed detector 51 outputs a signal corresponding to the engine speed (NE) of the engine 10. For example, an engine speed sensor (not shown) provided on the crankshaft of the engine 10 corresponds to the engine speed detector 51. A signal representing the engine speed (hereinafter referred to as NE signal) is input to the throttle ECU 1. More specifically, the NE signal is a signal in which a rising edge occurs every time the crankshaft of the engine rotates by a predetermined angle (for example, 10 °).

  Each cylinder of the engine 10 is provided with an injector (not shown) for fuel injection and an ignition plug (not shown). The output controller 70 controls the fuel injection amount to each cylinder of the engine 10 by controlling energization of each injector, and controls the ignition timing by controlling energization of each spark plug.

Next, the throttle ECU 1 will be described.
The throttle ECU 1 includes a power amount control unit 20, a required torque calculation unit 30, a power supply control unit 40, an abnormality determination unit 50, and an actual torque detection unit 60.

  First, an accelerator position signal from the accelerator operation amount detector 31 is input to the required torque calculator 30. The required torque calculation unit 30 takes into account the operation amount of the in-vehicle device (air conditioner, audio, etc.), the shift position or the status of shift change, in addition to the operation amount of the accelerator pedal 32 indicated by the accelerator position signal, The required torque is calculated by calculation. This required torque is the torque required to drive the vehicle as intended by the driver (in other words, according to the amount of operation of the accelerator pedal 32).

  A signal indicating the required torque calculated by the required torque calculating unit 30 (hereinafter, the description of “signal indicating” is omitted as appropriate) is an electric energy control unit 20, an abnormality determination unit 50, and an output control unit 70. Is output.

  The electric energy control unit 20 calculates the opening degree of the throttle valve 90 for obtaining the required torque input from the required torque calculation unit 30 so that the opening degree of the throttle valve 90 is controlled to the calculated opening degree. Control signal (control signal for controlling the driver 80) to output to the driver 80. Further, as shown in FIG. 1, a throttle sensor signal is also input to the electric energy control unit 20, and the electric energy control unit 20 also considers the opening of the throttle valve 90 represented by the throttle sensor signal. Thus, a control signal is output to the driver 80. That is, the opening degree of the throttle valve 90 is feedback-controlled.

  Next, the NE signal from the engine speed detector 51 is input to the actual torque detector 60. The actual torque detector 60 calculates torque (hereinafter referred to as actual torque) obtained from the gear ratio of the transmission, the differential gear ratio, the tire outer diameter, and the like in addition to the engine speed indicated by the NE signal. . In other words, the actual torque detector 60 calculates the torque that the vehicle tire actually transmits to the road surface by calculation. The actual torque calculated by the actual torque detection unit 60 is input to the abnormality determination unit 50.

  The abnormality determination unit 50 compares the required torque with the actual torque and determines whether there is an abnormality in the control of the throttle valve 90. For example, when the difference between the required torque and the actual torque is greater than a predetermined value, it is determined that an abnormality has occurred.

  Further, as shown in FIG. 1, a throttle sensor signal is also input to the abnormality determination unit 50. The abnormality determination unit 50 determines whether or not the throttle position sensor 92 is abnormal based on the throttle sensor signal. To do.

  The abnormality determination unit 50 outputs a signal indicating the determination result (hereinafter referred to as an abnormality determination signal) to the power supply control unit 40 and the output control unit 70. The output level of the determination signal is changed from an output level that indicates normality (low level in this example) to an output level that indicates abnormality (high level in this example).

  When the output level of the abnormality determination signal from the abnormality determination unit 50 becomes a high level, the power supply control unit 40 controls the drive of the motor 82 to the driver 80 by a cutoff / supply signal described later output to the driver 80. Prohibit or allow. Specifically, the output level of the cutoff / supply signal is periodically set to a high level indicating prohibition (shutdown) or a low level indicating permission (supply). On the other hand, when the abnormality determination signal is at the low level, that is, when it is normal, the output level of the cutoff / supply signal is continuously at the low level indicating permission. Here, the interruption / supply signal is a signal for specifically interrupting the voltage supply from the driver 80 to the motor 82 or permitting the voltage supply from the driver 80 to the motor 82.

  Here, when the output level of the cutoff / supply signal is a low level indicating permission, the driver 80 outputs a drive signal to the motor 82 in accordance with the control signal from the electric energy control unit 20 and outputs the drive signal of the motor 82. Execute drive control. On the other hand, when the output level of the cutoff / supply signal is a high level indicating cutoff, the drive control of the motor 82 is stopped by stopping the output of the drive signal to the motor 82.

  The output control unit 70 performs a predetermined fail sale process when the abnormality determination signal from the abnormality determination unit 50 becomes a high level indicating abnormality. For example, a fail-safe process is conceivable in which energization of an injector (not shown) is controlled and fuel injection to the engine by the injector is cut intermittently.

Next, FIG. 2 is a configuration diagram showing a specific configuration of the throttle ECU 1 and its periphery.
As shown in FIG. 2, the throttle ECU 1 includes a required torque calculation device 3, an abnormality determination device 5, a vehicle speed storage device 7, a gate output time generation device 9, a gate pulse generator 11, and a system clock generation device 13. And a system clock frequency dividing device 15 and logic switches 21, 23, 25.

  Here, if correspondence with FIG. 1 is described, the required torque calculation device 3 corresponds to the required torque calculation unit 30 and the electric energy control unit 20, and the abnormality determination device 5 corresponds to the abnormality determination unit 50 and the actual torque detection unit 60. The vehicle speed storage device 7, the gate output time generation device 9, the gate pulse generator 11, the system clock generation device 13, the system clock frequency divider 15, and the logic switches 21, 23, 25 are controlled to supply power. Corresponds to the portion 40.

  The required torque calculation device 3 has the function of the required torque calculation unit 30 and the function of the electric energy control unit 20 as described above. For example, a control signal for controlling the driver 80 is output from the required torque calculation device 3 to the driver 80, and the required torque is output to the abnormality determination device 5. Since other points have already been described, detailed description is omitted here.

  The abnormality determination device 5 has the function of the abnormality determination unit 50 and the function of the actual torque detection unit 60 as described above. The abnormality determination device 5 outputs the abnormality determination signal as described above to the logic switches 21 and 23. Since other points have already been described, detailed description is omitted here.

  The vehicle speed storage device 7 stores the vehicle speed. Specifically, a vehicle speed signal is input to the vehicle speed storage device 7 via the logic switch 21, and the vehicle speed storage device 7 periodically updates and stores the vehicle speed represented by the input vehicle speed signal. It is supposed to be.

  Here, the logic switch 21 switches connection / disconnection, and is in a closed state (connection state) in a normal state where no abnormality has occurred (when the output level of the abnormality determination signal is a low level indicating normal). ). That is, at the normal time, the vehicle speed signal is always input to the vehicle speed storage device 7.

  On the other hand, when the output level of the abnormality determination signal becomes a high level indicating abnormality, the logic switch 21 is in an open state (non-connected state). That is, at the time of abnormality, the vehicle speed signal is not input to the vehicle speed storage device 7.

According to this, for example, when a transition is made from a normal state to an abnormal state, the vehicle speed storage device 7 holds the vehicle speed before the abnormality is detected (for example, immediately before).
Next, the logic switch 23 includes input terminals a and b and an output terminal c, and the output terminal c is connected to either the input terminal a or the input terminal b. The logic switch 25 is the same. A signal having a high output level is always input to the input terminal a, and a signal having a low output level is always input to the input terminal b. Hereinafter, in the logic switch 23, the input terminal a side is also referred to as a high side, and the input terminal b side is also referred to as a low side.

  In a normal state (normal state), the logic switch 23 is connected to the low side and outputs a low level signal from the output terminal c. On the other hand, while the output level of the abnormality determination signal from the abnormality determination device 5 is high level indicating abnormality, the high level signal is output from the output terminal c by connecting to the high side. A signal output from the output terminal c of the logic switch 23 is input to the input terminal b of the logic switch 25.

  When the output level of the abnormality determination signal from the abnormality determination device 5 becomes a high level, the gate output time generation device 9 calculates a gate output time described later based on the vehicle speed stored in the vehicle speed storage device 7. Specifically, the gate output time information is stored in advance in a memory (for example, ROM) not shown in association with the vehicle speed information, and the gate output time generation device 9 refers to the memory to store the vehicle speed. The gate output time corresponding to the vehicle speed stored in the device 7 is read and acquired. Here, the gate output time represents a period during which a signal output from the system clock frequency divider 15 described later is input to the driver 80 as a cutoff / supply signal.

The gate output time calculated by the gate output time generator 9 is input to the gate pulse generator 11.
The gate pulse generator 11 outputs a signal to the logic switch 25, and sets the output level of the signal to a high level for a period corresponding to the gate output time calculated by the gate output time generator 9. More specifically, as shown in FIG. 2, the abnormality determination signal is input to the gate pulse generator 11, and the output level of the abnormality determination signal indicates abnormality in the gate pulse generator 11. When the level is high, the output level of the signal to the logic switch 25 is set to high level, and the high level is maintained for the gate output time. Hereinafter, a signal (pulse) output from the gate pulse generator 11 to the logic switch 25 is referred to as a gate pulse, and a period during which the output level of the signal is high is referred to as a pulse period.

The system clock generator 13 generates a clock that is used by each unit of the throttle ECU 1 as a reference for operation.
Further, the system clock frequency dividing device 15 outputs a signal obtained by dividing the clock input from the system clock generating device 13 to the input terminal a of the logic switch 25.

  Next, as described above, the logic switch 25 includes the input terminals a and b and the output terminal c, and the signal from the system clock frequency divider 15 is input to the input terminal a and the input terminal b is input. A signal from the logic switch 23 is input. The output terminal c is connected to the driver 80. As described above, the signal output from the output terminal c of the logic switch 25 is input to the driver 80 as a cutoff / supply signal.

The logic switch 25 is connected to the input terminal a side during the pulse period of the gate pulse, and is connected to the input terminal b side during other than the pulse period.
According to this, during the pulse period of the gate pulse, the signal output from the system clock frequency divider 15 is input to the driver 80 as a cutoff / supply signal via the logic switch 25, and except for the pulse period of the gate pulse, A signal output from the logic switch 23 is input to the driver 80 as a cutoff / supply signal via the logic switch 25.

Next, FIG. 3 is a flowchart showing an abnormality determination process executed by a microcomputer (not shown) of the throttle ECU 1.
In the abnormality determination process of FIG. 3, first, in S110, it is determined whether or not the value obtained by subtracting the required torque from the actual torque is greater than a predetermined value. If it is determined that the subtraction value is equal to or smaller than the predetermined value (S110: NO), it is determined that the difference between the actual torque and the required torque is within the allowable range, or the actual torque is smaller than the required torque (under torque). Then, the process proceeds to S160.

In S160, the output level of the cutoff / supply signal is set to a low level indicating permission.
Here, in this embodiment, when the actual torque is smaller than the required torque (under torque) as in S110: NO → S160, the drive control of the motor 82 by the driver 80 is not prohibited. This is because if it is prohibited, there is a concern that an undertorque state is further promoted. For example, if the fuel injection control system that controls fuel injection to the engine 10 (see FIG. 1) or the ignition control system that controls ignition (for example, the output control unit 70 in FIG. 1) or the like has an abnormality, the torque is too small. In this case, it is not preferable to prohibit the drive control of the driver 80 because of the above concerns.

  Next, when it is determined in S110 that the subtraction value of the actual torque-requested torque is larger than the predetermined value (S110: YES), it is determined that there is an abnormality (excessive torque), the process proceeds to S120, and the vehicle speed (vehicle speed storage device 7) is determined. The gate output time corresponding to the vehicle speed stored in the

  Next, it progresses to S130 and it is determined whether it is the pulse period of a gate pulse. If it is determined that it is a pulse period (S130: YES), the process proceeds to S140, and the signal from the system clock frequency divider 15 is output as a cutoff / supply signal. Then, after S140, the process returns to S130.

  If it is determined in S130 that it is not a pulse period (S130: NO), the process proceeds to S150, and the output level of the cutoff / supply signal is set to a high level indicating prohibition. Specifically, the signal from the logic switch 23 is output as a cutoff / supply signal. Thereafter, the process is terminated.

Next, FIG. 4 is a time chart showing the operation of the throttle ECU 1. FIG. 4 shows an example of transition from a normal state to an abnormal state.
In FIG. 4, the first stage represents a clock generated by the system clock generator 13.

The second level represents a frequency-divided signal from the system clock frequency divider 15.
The third level represents a signal output from the output terminal c of the logic switch 23 to the input terminal b of the logic switch 25.

  The fourth stage represents a signal (gate pulse) output from the gate pulse generator 11 to the logic switch 25. Here, in particular, it is an example at a low vehicle speed (here, for example, a low vehicle speed of less than 60 km / h assumed on a general road is used).

The fifth level represents a cutoff / supply signal output from the output terminal c of the logic switch 25 to the driver 80. In particular, this is an example at a low vehicle speed.
The sixth stage, like the fourth stage, represents a gate pulse, and here is an example particularly at a high vehicle speed (here, for example, 60 km / h or more assumed on a highway is a high vehicle speed).

The seventh stage, like the fifth stage, represents a cut-off / supply signal, and here is an example particularly at a high vehicle speed.
Here, first, the case of the low vehicle speed, that is, the first to fifth stages will be described.

  In FIG. 4, in the normal period, the output terminal c of the logic switch 23 is connected to the input terminal b side, and a low level signal is output from the output terminal c of the logic switch 23 as shown in the third stage. The

  As shown in the fourth stage, the gate pulse is at a low level (other than the pulse period). In this case, the logic switch 25 is connected to the input terminal b side (logic switch 23 side). Therefore, a low level signal from the logic switch 23 is output from the output terminal c of the logic switch 25.

That is, as shown in the fifth stage, the output level of the cutoff / supply signal is the same low level as the output level of the logic switch 23.
When an abnormality is detected at time T1, the output level of the abnormality determination signal (see FIG. 2) becomes a high level indicating the abnormality.

  Then, the logical switch 21 switches from a connected state to a non-connected state. As a result, the vehicle speed stored in the vehicle speed storage device 7 before the abnormality is detected (immediately before) is held in the vehicle speed storage device 7.

  The logic switch 23 is connected to the input terminal a side (high side). As a result, as shown in the “abnormal period” in the third stage, a high level signal is output from the output terminal c of the logic switch 23.

The gate output time generation device 9 calculates the gate output time based on the vehicle speed before the abnormality held in the vehicle speed storage device 7 is detected.
As shown in the fourth stage, the gate pulse generator 11 changes the output level of the output signal at the timing when the abnormality is detected (the timing when the output level of the abnormality determination signal becomes high) (low level). The high level is maintained for a period corresponding to the gate output time calculated by the gate output time generator 9.

  The logic switch 25 is connected to the system clock frequency divider 15 side (input terminal a side) in the pulse period of the gate pulse. Therefore, a signal from the system clock frequency divider 15 is output from the output terminal c of the logic switch 25.

That is, as shown in the “abnormal period” in the fifth stage, in the pulse period of the gate pulse, the signal from the system clock frequency divider 15 is output as a cutoff / supply signal.
Further, the signal output from the system clock frequency divider 15 is a pulse signal whose output level changes between a high level and a low level as shown in the second stage. For this reason, the driver 80 intermittently performs drive control of the motor 82.

  Then, at the end of the pulse period (time t1), the connection in the logic switch 25 is switched to the logic switch 23 side (input terminal b side), and as shown in the fifth stage, after time t1, the connection from the logic switch 23 is performed. The signal is output as a cut-off / supply signal. Since the logic switch 23 is connected to the high side during the abnormal period, the output level of the cutoff / supply signal is maintained at the high level after time t1.

  As shown in the sixth and seventh stages, the pulse period (gate output time) is longer at high vehicle speeds than at the fourth and fifth stage low vehicle speeds. . This is because more time is required to reduce the vehicle speed to a constant speed when the vehicle speed is high. In other words, more time for deceleration is taken to mitigate the deceleration shock.

Next, FIG. 5 is a diagram showing a change in the drive current value flowing through the motor 82. FIG. 5 shows an example of transition from a normal state to an abnormal state, as in FIG.
In FIG. 5, the first level is the same as the first level in FIG. 4, and represents a clock generated by the system clock generation device 13.

The second level is the same as the fifth level in FIG. In other words, it represents a cut-off / supply signal output from the output terminal c of the logic switch 25, and is particularly an example at a low vehicle speed.
The third level represents a change in the value of the drive current flowing through the motor 82 at low vehicle speeds.

The fourth level is the same as the seventh level in FIG. That is, it represents a cutoff / supply signal output from the output terminal c of the logic switch 25, and is an example at a high vehicle speed.
The fifth level represents a change in the value of the drive current flowing through the motor 82 at a high vehicle speed.

Here, first, the case of the low vehicle speed, that is, the first to third stages will be described.
In the example of FIG. 5, during a normal period, the vehicle is cruising at a constant speed, and the drive current changes at a substantially constant value. For example, before the time T1 when an abnormality occurs, in this example, the drive of the motor 82 (the opening / closing drive of the throttle valve 90) is controlled, and the drive current value increases.

  However, when an abnormality is detected at time T1, the output level of the cutoff / supply signal changes, and here, the output level of the cutoff / supply signal first becomes high, and drive control of the motor 82 is prohibited. . That is, the power supply from the driver 80 to the motor 82 is interrupted. For this reason, a drive current value falls.

  On the other hand, when the output level of the cutoff / supply signal becomes low level and the drive control of the motor 82 is permitted, the drive control of the motor 82 by the driver 80 is resumed. For this reason, a drive current value becomes large. Thereafter, such an operation is repeated in accordance with the cutoff / supply signal between time T1 and time t1. In this case, the throttle valve 90 (see FIG. 1) repeats closing → opening → closing, and the intake air amount gradually decreases.

  For example, when the drive control of the motor 82 is prohibited and the throttle valve 90 is closed, if the throttle valve 90 is closed halfway rather than to the initial position, the intake air path to the engine 10 is narrowed and the intake air amount is reduced. At the same time, when the drive control of the motor 82 is permitted and the throttle valve 90 is opened, the intake air amount increases again. For example, it is conceivable that the intake air amount gradually decreases. In such a case, it is conceivable that the throttle valve 90 gradually returns to the initial position, for example.

  Further, when the drive control of the motor 82 is prohibited and the throttle valve 90 is closed, air in the intake passage from the vicinity of the throttle valve 90 to the engine 10 is supplied to the engine 10 by inertia even if the throttle valve 90 is closed to the initial position. Then, it is conceivable that the intake air amount gradually decreases, for example, when the drive control of the motor 82 is permitted and the throttle valve 90 is opened, the intake air amount increases again.

  As shown in the second stage, when the cutoff / supply signal goes high after time t1, the drive control of the motor 82 is completely prohibited, and the drive current value decreases as shown in the third stage. Approximately 0.

In the case of high vehicle speed, the period (pulse period) in which the drive control of the motor 82 is intermittently prohibited is different from that in the low vehicle speed except that the other period is the same as in the low vehicle speed. is there.
Next, FIG. 6 is a graph showing the effect of this embodiment. Specifically, the relationship between time (horizontal axis) and vehicle speed (vertical axis) is shown. In the graph of FIG. 6, a solid line represents an example of the present embodiment, and a wavy line represents a conventional example to which the present invention is not applied.

  In the conventional example indicated by the wavy line, when an abnormality is detected at time T1, the drive control of the motor 82 is completely prohibited, so the throttle valve 90 immediately returns to the initial position, and the intake air amount rapidly decreases. For this reason, the number of revolutions of the engine is abruptly decreased, and the vehicle speed is also rapidly decreased.

  On the other hand, in the example of the present embodiment indicated by the solid line, when an abnormality is detected at time T1, first, the drive control of the motor 82 is intermittently prohibited as described above. For this reason, as described above, the intake air amount gradually decreases, the engine speed gradually decreases, and the vehicle speed also gradually decreases as compared with the conventional example.

  As described above, according to the present embodiment, when an abnormality occurs in the throttle control system that drives opening / closing of the throttle valve 90, the driver 80 prohibits the drive control of the throttle valve 90 (motor 82) by the vehicle. In this case, in particular, the driving control of the driver 80 is intermittently prohibited. For this reason, the throttle valve 90 repeats closing → opening → closing, and the amount of intake air to the engine 10 is gradually reduced to prevent overrun of the vehicle and avoid deceleration shock and sudden engine stall. be able to. Accordingly, it is possible to realize safer vehicle control while not causing discomfort to the driver.

  In addition, the period during which the drive control of the driver 80 is intermittently prohibited is made different between, for example, a low engine speed and a high engine speed. Specifically, in the case of high rotation, the prohibited period is made longer. Therefore, regardless of whether the engine speed is low or high, the engine speed, and hence the vehicle speed, can be gradually and efficiently reduced. Accordingly, it is possible to more reliably avoid a deceleration shock and a sudden engine stall.

  In the present embodiment, the required torque calculation device 30 and the driver 80 correspond to throttle driving means, and the configuration shown in FIG. 2 (and the portion excluding the output control unit 70 in FIG. 1) corresponds to the throttle control system. The abnormality determination device 5 corresponds to an abnormality detection means and outputs a cutoff / supply signal. Specifically, the vehicle speed storage device 7, the gate output time generation device 9, the gate pulse generator 11, the system clock generation device 13, and the system The clock frequency divider 15 and the logic switches 21, 23, 25 correspond to fail-safe means, the gate output time generation device 9 corresponds to period calculation means, the accelerator operation amount detection unit 31, the vehicle speed detection unit 41, and the engine The rotation speed detection unit 51 corresponds to state detection means.

Note that the first embodiment may be configured as in the following modifications.
<Modification>
FIG. 7 is a schematic configuration diagram of a modified engine control system.

In the present modification, in addition to the configuration of FIG. 1, the abnormality determination unit 50 further determines whether there is an abnormality in the driver 80, the motor 82, and the output control unit 70.
Specifically, a signal for detecting whether or not the driver 80 and the motor 82 are abnormal (hereinafter, referred to as a driver abnormality detection signal) is output from the driver 80 to the abnormality determination unit 50. For example, referring to FIG. 2, when the present modification is applied, a driver abnormality detection signal is output from the driver 80 to the abnormality determination device 5.

  In addition, a signal for detecting whether or not the output control unit 70 is abnormal is output from the output control unit 70 to the abnormality determination unit 50. The output control unit 70 is not originally included in the throttle control system that drives opening and closing of the throttle valve 90, but may be considered to be included in the throttle control system in a broad sense.

  Here, for example, abnormalities assumed for the driver 80 and the motor 82 are abnormalities in which excessive current flows in the driver 80 (overcurrent abnormality), and abnormalities in which the current value flowing in the driver 80 continues at a maximum value for a predetermined time or more ( Full power abnormality).

  As the former overcurrent abnormality, for example, an example in which an excessive current flows due to a circuit failure in the driver 80 can be considered. More specifically, the circuit failure includes, for example, a failure in which a drain and a source are short-circuited in a transistor constituting an H-bridge circuit for switching the energization direction to the motor 82. Further, as the latter full power abnormality, for example, when the throttle valve 90 is driven in the opening direction, the driving is obstructed by, for example, some obstacle (foreign matter) or the like. An example where the full power state continues to approach the degree is conceivable.

According to this modified example in which the presence / absence of abnormality of the driver 80, the motor 82, and the output control unit 70 is also detected, the safety is further improved.
[Second Embodiment]
Next, a second embodiment will be described.

FIG. 8 is a configuration diagram illustrating a specific configuration of the throttle ECU 1 according to the second embodiment and the periphery thereof.
In the first embodiment, when an abnormality occurs, the drive control of the motor 82 is merely intermittently prohibited (in other words, the vehicle speed is controlled in an open loop). In the second embodiment, the vehicle speed is controlled in a closed loop when an abnormality occurs. (Feedback control) is different.

  Specifically, the throttle ECU 1 of the second embodiment shown in FIG. 8 includes an upper limit vehicle speed determination device 35 and a DUTY selection device 37, as compared with the throttle ECU 1 of FIG. 2 (first embodiment). In addition, a PWM device 39 is provided instead of the system clock frequency dividing device 15.

  Further, a difference is that a microcomputer (not shown) of the throttle ECU 1 executes the abnormality determination process of FIG. 9 instead of the abnormality determination process of FIG. Furthermore, the microcomputer is different in that the PWM cycle trigger process of FIG. 10 is periodically executed.

Hereinafter, the different points will be specifically described.
First, the upper limit vehicle speed determination device 35 is inputted with an abnormality determination signal, a gate pulse from the gate pulse generator 11, and a PWM signal from a PWM device 39 to be described later. Further, the upper limit vehicle speed determination device 35 can read and acquire, for example, the vehicle speed before the occurrence of an abnormality (hereinafter referred to as the vehicle speed before the abnormality) stored in the vehicle speed storage device 7 from the vehicle speed storage device 7. .

  Then, when the output level of the abnormality determination signal becomes a high level indicating abnormality, the upper limit vehicle speed determination device 35 acquires the vehicle speed before the abnormality from the vehicle speed storage device 7 and calculates the target vehicle speed after deceleration. Further thereafter, during the pulse period of the gate pulse, the target vehicle speed is calculated at a constant period synchronized with the period of the PWM signal. Here, the target vehicle speed is referred to as the upper limit vehicle speed. The upper limit vehicle speed calculated by the upper limit vehicle speed determination device 35 at a constant cycle is input to the DUTY selection device 37 every time it is calculated.

In addition to the upper limit vehicle speed, the DUTY selection device 37 receives a vehicle speed signal, a gate pulse, and a PWM signal.
Then, the DUTY selection device 37 sets the cutoff / supply signal high based on the vehicle speed represented by the vehicle speed signal (that is, the actual vehicle speed, hereinafter referred to as the actual vehicle speed) and the upper limit vehicle speed in the pulse period of the gate pulse. And the ratio of low, that is, the DUTY (duty) ratio. Specifically, a map for determining the DUTY ratio from the actual vehicle speed and the upper limit vehicle speed is stored in a memory (not shown) such as a ROM, and the DUTY selection device 37 refers to the map to determine the DYTU ratio. Is to decide. The DUTY ratio determined by the DUTY selection device 37 is input to the PWM device 39.

  The PWM device 39 outputs a PWM signal that matches the DUTY ratio determined by the DUTY selection device 37 to the input terminal a of the logic switch 25. The PWM signal is also output to the upper limit vehicle speed determination device 35 and the DUTY selection device 37 as described above.

  Here, the upper limit vehicle speed determination device 35 does not execute the process for calculating the upper limit vehicle speed except during the pulse period of the gate pulse, and the DUTY selection device 37 performs the process for determining the DUTY ratio. Do not run. This is because the logic switch 25 is connected to the input terminal b side except during the pulse period of the gate pulse, so that the PWM signal from the PWM device 39 is not output as a cutoff / supply signal via the logic switch 25. Because. In this way, it is possible to prevent unnecessary processing from being executed, thereby reducing the load on the throttle ECU 1 (for example, the load on the CPU of the microcomputer) and suppressing power consumption.

Next, FIG. 9 will be described.
The abnormality determination process of FIG. 9 differs from the abnormality determination process of FIG. 3 (first embodiment) in that the process of S210 is executed instead of the process of S140. In the abnormality determination process of FIG. 9, the same steps as those of the abnormality determination process of FIG.

  Specifically, in FIG. 9, when it is determined in S130 that it is the pulse period of the gate pulse (S130: YES), the process proceeds to S210, and the PWM signal from the PWM device 39 is output as a cutoff / supply signal. Specifically, the PWM device 39 outputs a PWM signal to the input terminal a of the logic switch 25, and the pulse period of the gate pulse is connected to the input terminal a side in the logic switch 25. And after the process of S210, it returns to S130 again.

Next, the PWM cycle trigger process of FIG. 10 will be described.
In the PWM cycle trigger process of FIG. 10, first, in S310, it is determined whether or not the subtraction value of the actual torque and the required torque is larger than a predetermined value. If it is determined that the subtraction value is equal to or less than the predetermined value (S310: NO), the process is terminated as it is.

On the other hand, if it is determined in S310 that the subtraction value is larger than the predetermined value (excess torque) (S310: YES), the process proceeds to S320, and it is determined whether or not it is the pulse period of the gate pulse.
If it is determined in S320 that it is not a pulse period (S320: NO), the process is terminated as it is.

  On the other hand, if it is determined in S320 that it is a pulse period (S320: YES), the process proceeds to S330, and it is determined whether or not the previous abnormality determination result is “normal”. The abnormality determination result is stored in a predetermined memory (for example, RAM) for each determination, and in S330, information on the abnormality determination result stored in the memory is referred to.

If it is determined in S330 that the previous abnormality determination result is “normal” (S330: YES), it is determined that the normal state has changed to the abnormal state, and the process proceeds to S340.
In S340, the vehicle speed (pre-abnormal vehicle speed) stored in the vehicle speed storage device 7 is acquired from the vehicle speed storage device 7, and the acquired abnormal vehicle speed is set as the upper limit vehicle speed. Then, the process proceeds to S360.

  On the other hand, if it is determined in S330 that the previous abnormality determination result is not “normal”, that is, “abnormal” (S330: NO), it is determined that the abnormal state continues, and the process proceeds to S350.

  In S350, a vehicle speed obtained by subtracting a predetermined speed from the upper limit vehicle speed calculated last time (at least calculated in S340 when an abnormality occurs) is set as a new upper limit vehicle speed. Then, the process proceeds to S360.

In S360, it is determined whether the actual vehicle speed is higher than the upper limit vehicle speed calculated in S340 or S350.
If it is determined in S360 that the actual vehicle speed is greater than the upper limit vehicle speed (S360: YES), the process proceeds to S380, and a DUTY ratio is selected such that the current actual vehicle speed is reduced. In this example, the DUTY ratio is, for example, 50%, but this DUTY ratio can take various values depending on the vehicle speed and various other conditions.

  On the other hand, if it is determined in S360 that the actual vehicle speed is equal to or lower than the upper limit vehicle speed (S360: NO), the process proceeds to S370, and a DUTY ratio that maintains the current actual vehicle speed is determined. In this example, the DUTY ratio is 25%, for example, but as described above, the DUTY ratio can take various values depending on various conditions.

Then, after the process of S370 or S380, the process ends.
Next, FIG. 11 is a time chart showing the operation of the throttle ECU 1. FIG. 11 shows an example of transition from a normal state to an abnormal state.

In FIG. 11, the first to third stages are the same as the first to third stages in FIG. 4.
In FIG. 11, the fourth level represents a PWM signal output from the PWM device 39 to the input terminal a of the logic switch 25.

The fifth level represents a cutoff / supply signal output from the output terminal c of the logic switch 25 to the driver 80.
The sixth row represents the actual vehicle speed and the upper limit vehicle speed. In the sixth stage, the solid line represents the actual vehicle speed, and the wavy line represents the upper limit vehicle speed.

  First, as shown in the fourth stage, the PWM device 39 outputs a pulse signal having a period S, for example, and the DUTY ratio of the pulse signal is determined by the DUTY selection device 37 in the pulse period of the gate pulse. Set to DUTY ratio.

As shown in the fifth stage, the cutoff / supply signal is a PWM signal output from the PWM device 39 in the pulse period of the gate pulse.
As shown in the sixth stage, when an abnormality is detected at time T1, an upper limit vehicle speed is set. The first upper limit vehicle speed, that is, the upper limit vehicle speed immediately after the abnormality is detected, is the same as the vehicle speed stored in the vehicle speed storage device 7 (S330: YES → S350 in FIG. 10). In other words, this means that when an abnormality occurs, the actual vehicle speed does not exceed at least the vehicle speed immediately before the abnormality occurs. In the normal period, the upper limit vehicle speed is not calculated (in this example, it is 0 km / h, for example).

  In this example, the actual vehicle speed is slightly higher than the upper limit vehicle speed around time T1. Then, as described above, in FIG. 10, S360: YES → S380, and the DUTY ratio is, for example, 50%. Thereafter, at time t2, the abnormal state continues (S330: NO), and a vehicle speed obtained by subtracting a predetermined speed from the previous upper limit vehicle speed calculated at time T1 is set as a new upper limit vehicle speed ( S350).

In this example, the actual vehicle speed is slightly below the upper limit vehicle speed at time t2. In this case, the DUTY ratio is, for example, 25% (S360: NO → S370).
Since it is the same thereafter, detailed description will be omitted. For example, at time t3, the DUTY ratio is set to 25%, and at time t4, the DUTY ratio is set to 50%.

  Actually, the actual vehicle speed between time T1 and time t1, more specifically between time T1 and time t1, time t1 to time t2, time t2 to time t3, and time t4 to time t1. Accordingly, the duty ratio is determined at a smaller cycle, and feedback control is performed so that the actual vehicle speed approximates the upper limit vehicle speed.

  As described above, according to the second embodiment, when an abnormality occurs, the upper limit vehicle speed is determined in stages, and feedback control is performed so that the actual vehicle speed approximates the upper limit vehicle speed. Smoothly decelerate. Therefore, it becomes possible to avoid the deceleration shock and the engine stall more reliably.

In the second embodiment, the vehicle speed storage device 7, the gate output time generation device 9, the gate pulse generator 11, the system clock generation device 13, the logical switches 21, 23, 25, the upper limit vehicle speed determination device 35, and the DUTY selection device. 37 and the PWM device 39 correspond to the fail-safe means of claims 4 and 5.
[Third Embodiment]
Next, a third embodiment will be described.

FIG. 12 is a configuration diagram illustrating a specific configuration of the throttle ECU 1 according to the third embodiment and the periphery thereof.
The throttle ECU 1 in FIG. 12 is different from the throttle ECU 1 in FIG. 2 (first embodiment) in that a logic switch 27 is provided between the logic switch 25 and the driver 80.

Further, a difference is that a microcomputer (not shown) of the throttle ECU 1 periodically executes the brake interlocking process of FIG. 13 in addition to the process of FIG.
First, the logic switch 27 includes input terminals a and b and an output terminal c. A signal from the logic switch 25 is input to the input terminal a, and a signal whose output level is high is input to the input terminal b. Is always input. Furthermore, a signal (hereinafter referred to as a brake signal) indicating the amount of operation of the brake pedal 62 is input to the logic switch 27 from the brake pedal sensor 63 of the vehicle.

  When the abnormality determination device 5 detects an abnormality, the logic switch 27 operates while the output level of the brake signal is an output level (for example, a low level) indicating that the brake pedal 62 is not operated. Connect to the switch 25 side. In this case, a signal output from the output terminal c of the logic switch 25 is output to the driver 80 as a cutoff / supply signal via the logic switch 27. Here, the signals output from the logic switch 25 are as described in the first embodiment.

  On the other hand, the logic switch 27 is connected to the high side when the output level of the brake signal becomes an output level (for example, high level) indicating that the brake pedal 62 is operated. Therefore, a high level signal is output to the driver 80 as a cutoff / supply signal.

  That is, when an abnormality is detected by the abnormality determination device 5, when the brake pedal 62 is operated, the drive control of the motor 82 by the driver 80 is immediately prohibited, and the prohibition continues. .

Next, the brake interlocking process in FIG. 13 will be described.
In the brake interlocking process of FIG. 13, first, in S410, it is determined based on the brake signal whether or not the brake pedal 62 has been operated. If it is determined that the brake pedal 62 has not been operated (S410: NO), the processing is terminated as it is.

On the other hand, if it determines with the brake pedal 62 having been operated by S410 (S410: YES), it will transfer to S420.
In S420, the output level of the cutoff / supply signal is set to a high level. Specifically, the connection in the logic switch 27 is switched to the high side. Thereafter, the process is terminated.

Next, FIG. 14 is a time chart showing the operation of the throttle ECU 1 of the third embodiment.
In FIG. 14, the first to fourth stages are the same as the first to fourth stages in FIG. 4.

Further, in FIG. 14, the fifth row represents a brake signal.
The sixth row represents a cutoff / supply signal output from the output terminal c of the logic switch 27 to the driver 80.

  As shown in FIG. 14, when an abnormality is detected at time T1, the gate pulse rises as described above, and the output from the output terminal c of the logic switch 25 is the signal from the system clock frequency dividing device 15. become. The logic switch 27 is connected to the input terminal a side (logic switch 25 side). That is, the cutoff / supply signal is a signal output from the output terminal c of the logic switch 25, that is, a frequency division signal from the system clock frequency divider 15.

  In the example of FIG. 14, the output level of the brake signal is changed from the low level to the high level at time T2. That is, the brake pedal 62 is operated at time T2.

  Then, the connection in the logic switch 27 is switched to the input terminal b side (high side). For this reason, the output level of the cutoff / supply signal from the output terminal c of the logic switch 27 becomes a high level. Therefore, in this case, the drive control of the motor 82 by the driver 80 is prohibited.

  As described above, according to the third embodiment, the operation of the brake pedal 62 by the driver, in other words, the intention of the driver is reflected, so that the intention of the driver matches the behavior of the vehicle. It becomes like this. Therefore, it is possible to realize vehicle control that avoids a deceleration shock and an engine stall and at the same time does not give the driver a sense of incongruity.

  In the third embodiment, the vehicle speed storage device 7, the gate output time generating device 9, the gate pulse generator 11, the system clock generating device 13, the system clock frequency dividing device 15, and the logic switches 21, 23, 25, 27. Corresponds to the fail-safe means of claim 6.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various form can be taken within the technical scope of this invention.
For example, in the above embodiment, the driver 80 may be packaged in an IC package and the driver 80 may be mounted on the throttle ECU 1.

  In the above embodiment, the drive control of the motor 82 by the driver 80 can be prohibited even when the torque is too small (S110: NO in FIG. 3). Furthermore, in this case, if the under torque is caused by an abnormality in the throttle control system, the drive control of the driver 80 can be prohibited. For example, it is assumed that the throttle valve 90 is erroneously operating in the closing direction due to an abnormality in the throttle control system, or the throttle valve 90 does not operate in the opening direction. In this case, the drive control of the driver 80 is prohibited. It is effective to do.

  In the above embodiment, the gate output time generation device 9 reads out and obtains the gate output time corresponding to the vehicle speed stored in the vehicle speed storage device 7 from the memory. You may comprise so that the gate output time may be calculated based on a predetermined arithmetic expression using the stored vehicle speed data.

  In the above-described embodiment, not only a period (gate output time) in which drive control of the motor 82 is intermittently prohibited, but also an intermittent pattern may be set based on the vehicle speed before the occurrence of an abnormality. In this case, an intermittent pattern is determined in advance according to the vehicle speed, and an intermittent pattern is selected according to the vehicle speed before the occurrence of an abnormality when an abnormality occurs, and the drive control of the motor 82 is intermittently performed with the selected pattern. Should be prohibited. That is, the vehicle speed may be controlled open.

  Further, a configuration unique to the third embodiment that includes the logic switch 27 and controls the output of the cutoff / supply signal based on the brake signal may be applied to the second embodiment.

It is a schematic block diagram of the engine control system of 1st Embodiment. It is a block diagram showing the specific content of throttle ECU1 of 1st Embodiment. It is a flowchart of the abnormality determination process performed in throttle ECU1 of 1st Embodiment. 3 is a time chart showing the operation of the throttle ECU 1; 6 is a time chart showing a change in drive current value in a motor 82 that drives a throttle valve 90; It is a graph showing the effect of this embodiment. It is a schematic block diagram of the engine control system of 2nd Embodiment. It is a block diagram showing the specific content of throttle ECU1 of 2nd Embodiment. It is a flowchart of the abnormality determination process performed in throttle ECU1 of 2nd Embodiment. It is a flowchart of the PWM period trigger process performed in throttle ECU1 of 2nd Embodiment. It is a time chart showing the effect | action of throttle ECU1 of 2nd Embodiment. It is a block diagram showing the specific content of throttle ECU1 of 3rd Embodiment. It is a flowchart of the brake interlocking process performed in throttle ECU1 of 3rd Embodiment. It is a time chart showing the effect | action of throttle ECU1 of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Throttle ECU, 3 ... Request torque calculating device, 5 ... Abnormality determination device, 7 ... Vehicle speed memory | storage device, 9 ... Gate output time generation device, 10 ... Engine, 11 ... Gate pulse generator, 12 ... Intake passage, 13 ... System clock generator, 15 ... system clock frequency divider, 20 ... power amount control unit, 21, 23, 25, 27 ... logic switch, 30 ... required torque calculation unit, 31 ... accelerator operation amount detection unit, 32 ... accelerator pedal 33 ... Accelerator pedal sensor, 35 ... Upper limit vehicle speed determination device, 37 ... DUTY selection device, 39 ... PWM device, 40 ... Power supply control unit, 41 ... Vehicle speed detection unit, 50 ... Abnormality determination unit, 51 ... Engine speed detection , 60 ... actual torque detector, 62 ... brake pedal, 63 ... brake pedal sensor, 70 ... output controller, 80 ... driver, 82 ... motor, 9 ... throttle valve, 92 ... throttle position sensor.

Claims (6)

Throttle drive means for driving a throttle valve provided in the intake system of the internal combustion engine;
At least abnormality detecting means for detecting the presence or absence of an abnormality in a throttle control system including the throttle driving means;
An electronic control device comprising a fail safe means for prohibiting the operation of the throttle drive means when at least an abnormality of the throttle control system is detected by the abnormality detection means,
The electronic controller according to claim 1, wherein the fail-safe means intermittently prohibits the operation of the throttle driving means. The electronic control device according to claim 1.
A state detecting means for detecting, as a detection target, the rotational speed of the internal combustion engine or the vehicle speed of the vehicle on which the internal combustion engine is mounted;
Based on the detection result detected by the state detection unit immediately before the abnormality detection unit detects an abnormality of the throttle control system, the period during which the fail safe unit intermittently prohibits the operation of the throttle drive unit is calculated. A period calculation means for
The electronic controller according to claim 1, wherein the fail safe means intermittently prohibits the operation of the throttle driving means during the period calculated by the period calculating means. The electronic control device according to claim 1 or 2,
The throttle drive means supplies operating power to an actuator for adjusting the opening of the throttle valve,
The electronic controller according to claim 1, wherein the fail-safe means intermittently prohibits the operation of the throttle drive means for supplying operating power to the actuator. The electronic control device according to claim 1.
A state detecting means for detecting, as a detection target, the rotational speed of the internal combustion engine or the vehicle speed of a vehicle in which the internal combustion engine is mounted;
The fail-safe means sets a target value of the detection target when an abnormality of the throttle control system is detected by the abnormality detection means, and a detection result detected by the state detection means is set with the set target value. As described above, the electronic control device is characterized in that the operation of the throttle driving means is intermittently prohibited and the target value is gradually changed to a smaller value. The electronic control device according to claim 2 or claim 3,
The fail-safe means sets a target value of the detection target when an abnormality of the throttle control system is detected by the abnormality detection means, and a detection result detected by the state detection means is set with the set target value. As described above, the operation of the throttle driving means is intermittently prohibited during the period calculated by the period calculating means, and the target value is gradually changed to a smaller value. An electronic control device characterized by that. The electronic control device according to any one of claims 1 to 5,
A signal indicating the operation state of a brake pedal provided in a vehicle equipped with the internal combustion engine (hereinafter referred to as a brake operation signal) is input.
The fail-safe means determines whether or not the brake pedal has been operated based on the brake operation signal when an abnormality of the throttle control system is detected by the abnormality detection means, and the brake pedal is operated. An electronic control device characterized in that, if it is determined, the operation of the throttle driving means is continuously prohibited.

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