JP2020012384A - Electronic control device - Google Patents

Abstract

To provide an electronic control device which can detect a failure of an actuator drive circuit in an earlier stage even if energization to an actuator is insufficient.SOLUTION: An electronic control device 102 comprises an actuator drive circuit 107 for switching energization and non-energization to an actuator 104, and a center arithmetic unit 108 for controlling the actuator 104 and the actuator drive circuit 107. The center arithmetic unit 108 comprises an actuator function abnormality detection part 110 for detecting a function abnormality of the actuator. When the function abnormality of the actuator is detected by the actuator function abnormality detection part 110, the control device controls the actuator drive circuit 107 so as to switch the energization and the non-energization to the actuator 104.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic control device, and more particularly to an electronic control device for a vehicle.

  2. Description of the Related Art In an electronic control unit of a vehicle, energization and non-energization of an actuator are controlled by an FET (Field Effect Transistor) in order to operate an actuator provided in various valves, a fuel injection device, an internal combustion engine, and the like. Actuator drive circuit is employed. In such an actuator drive circuit, if a circuit failure occurs, the actuator cannot operate as desired. Therefore, an electrical failure in the actuator drive circuit, for example, disconnection of an electrical connection, short to power (short circuit to the power supply side), or ground fault ( There is a case where a circuit failure detection unit for detecting a failure such as a short circuit on the ground side is provided.

  However, in the circuit failure detection unit provided in such an actuator drive circuit, whether or not a circuit failure can be detected depends on the on / off state of the FET. For example, when the FET is turned on and the actuator is energized, the flowing current is measured, and if the measured current is an overcurrent, a short-to-power fault can be detected. Since there is no circuit failure, it becomes impossible to detect a circuit failure. For this reason, in the case of an actuator having a small chance of turning on the FET (in other words, in a case where the energization to the actuator is small), it is difficult to early detect a circuit failure such as the above-described short-to-power fault. If early detection of a circuit failure becomes difficult, the function failure of the actuator is caused by the circuit failure, and there is a problem that the actuator cannot operate.

  In order to solve such a problem, a method of using each sensor arranged around the actuator and detecting a circuit failure based on a result detected by the sensor has been studied. For example, Patent Literature 1 below discloses a method of detecting a circuit failure at an early stage by controlling the ON / OFF state of the FET for detecting a circuit failure at a timing at which the driving performance and the exhaust performance of the vehicle are not adversely affected. ing.

JP 2010-121595 A

  However, depending on the actuator, there may be few opportunities to control the FET at a timing when the driving performance and exhaust performance of the vehicle are not adversely affected, or there may be no actuator at all. As a result, even if the method disclosed in Patent Document 1 is used, the above problem cannot be fundamentally solved.

  The present invention has been made in order to solve such a technical problem, and provides an electronic control device that can detect a failure in an actuator drive circuit at an early stage even when the power to the actuator is small. With the goal.

  An electronic control device according to the present invention includes: an actuator drive circuit that switches between energization and non-energization of an actuator; and a central processing unit that controls the actuator and the actuator drive circuit. An actuator function abnormality detection unit that detects a function abnormality of the actuator, and when the actuator function abnormality detection unit detects a function abnormality of the actuator, the actuator drive circuit switches between energization and non-energization of the actuator. Control.

  According to the present invention, when an actuator function abnormality detection unit detects an actuator function abnormality, the central processing unit controls the actuator drive circuit to switch between energization and non-energization of the actuator. The number of energizing opportunities can be increased. For this reason, even if the energization to the actuator is small, a failure in the actuator drive circuit can be detected early.

It is a lineblock diagram showing the control system provided with the electronic control unit concerning an embodiment. It is a schematic diagram which shows the vehicle internal combustion engine which is a control object apparatus. It is a flowchart which shows the control processing of an electronic control unit. 5 is a time chart related to control processing of the electronic control device.

  Hereinafter, an embodiment of an electronic control device according to the present invention will be described with reference to the drawings. In the present embodiment, as described later, the actuator function abnormality detection unit determines whether or not there is a function abnormality of the actuator, and when it is determined that the function is abnormal, the function abnormality is detected. become. Therefore, determining that there is a functional abnormality has the same meaning as detecting a functional abnormality, and determining that there is no functional abnormality has the same meaning as not detecting a functional abnormality.

  FIG. 1 is a configuration diagram illustrating a control system including an electronic control device according to the embodiment. As shown in FIG. 1, the control system 100 mainly includes a control target device 101 and an electronic control device 102 that controls the control target device 101.

  The control target device 101 includes a power supply 103, an actuator 104 that is a detection target of a failure and a malfunction of a drive circuit, an electric load 105 built in the actuator 104, and a sensor 106 that detects a state of the actuator 104. I have. The power supply voltage of the power supply 103 is, for example, 15V.

  The electronic control unit 102 includes an actuator drive circuit 107 that switches between energization and non-energization of the actuator 104, and a central processing unit 108 that controls the actuator 104 and the actuator drive circuit 107. The central processing unit 108 further includes an actuator function abnormality detection unit 110 that detects a function abnormality of the actuator 104, an actuator drive circuit failure detection unit 111 that detects a failure of the actuator drive circuit 107, and a control method of the actuator drive circuit 107. An actuator control switching unit 112 to be switched, a normal actuator control unit 113 switched by the actuator control switching unit 112, and an actuator control unit 114 for circuit failure detection are provided.

  Here, the malfunction of the actuator 104 indicates that the function of the actuator 104 cannot be performed. For example, when the actuator is a valve, the valve is closed and fixed due to a power short or the like, and the valve cannot be opened or closed due to a clogged valve. And the like. Further, the closed and fixed state of the valve means that the valve is fixed in a closed state, in other words, a state where the valve cannot be opened even if the valve is to be opened.

  The actuator drive circuit 107 includes an FET 115, a current measuring device 116 for measuring a current flowing through the FET 115, an FET on / off command unit 117 for controlling on / off of the FET 115, and a current value measured by the current measuring device 116. And an overcurrent detection unit 118 that detects an overcurrent based on As shown in FIG. 1, the electric load 105 of the controlled device 101, the FET 115 of the actuator drive circuit 107, the current measuring device 116, and the ground 109 are electrically connected in series in this order.

  The FET 115 is connected to a power supply 120 via a pull-up resistor 119. A diode 121 is connected between the power supply 120 and the pull-up resistor 119. The power supply voltage of the power supply 120 is, for example, 2.5V. The FET on / off command unit 117 is connected to the actuator control switching unit 112 and controls on / off of the FET 115 based on a control command from the actuator control switching unit 112. On the other hand, when the overcurrent is detected by the overcurrent detection unit 118, the FET on / off command unit 117 ignores the control command from the actuator control switching unit 112 and forcibly turns off the FET 115, and Thus, the actuator driving circuit 107 is prevented from being damaged.

  Various devices such as a vehicle internal combustion engine, an inverter, and a motor are applied to the control target device 101. Here, an example in which the control target device 101 is the vehicle internal combustion engine 201 will be described with reference to FIG. .

  FIG. 2 is a schematic diagram illustrating a vehicle internal combustion engine that is a device to be controlled. As shown in FIG. 2, the vehicle internal combustion engine 201 includes an intake pipe 202 that takes in outside air (that is, air) into the interior of the vehicle internal combustion engine 201, a throttle valve 203 that controls the amount of air taken in the intake pipe 202, and A cylinder 204 for injecting fuel into the taken-in air to form an air-fuel mixture and compressing and burning the air-fuel mixture to extract combustion energy, and discharging the combustion gas obtained by the cylinder 204 to the outside of the vehicle internal combustion engine 201. An exhaust pipe 205, a turbocharger 206 that compresses and sends out air on the intake pipe 202 side by rotating a turbine using a flow rate of air passing through the exhaust pipe 205, and a pressure of intake air compressed by the turbocharger 206. Pipe pressure sensor 207 for detecting air pressure and the pressure of air compressed by the turbocharger 206. And a turbocharger bypass valve 208 to release from Bochaja 206 in front of the intake pipe 202.

  The throttle valve 203 and the turbocharger bypass valve 208 are connected to the electronic control unit 102, and their opening and closing operations are controlled by the electronic control unit 102. The turbocharger bypass valve 208 corresponds to the above-described actuator 104, and the opening and closing of the valve body is performed by driving the actuator 104. In the following description, the turbocharger bypass valve 208 may be called the actuator 104.

  This turbocharger bypass valve 208 releases the excess pressure supercharged by the turbocharger 206 to the intake pipe 202 before the turbocharger 206 when the throttle valve 203 is rapidly closed, so that the throttle valve 203 This is a device for preventing an excessive load from being generated in the turbocharger 206. Here, the operation of the turbocharger bypass valve 208 in the direction of releasing the excess pressure by the valve is defined as opening, and the operation in the opposite direction is defined as closing.

  Normally, the turbocharger bypass valve 208 is controlled so as to be opened for a short time when releasing the excess pressure, so that the time for closing the valve is overwhelmingly long. For this reason, the turbocharger bypass valve 208 can be said to be the dominant actuator. In addition, the turbocharger bypass valve 208 is an actuator that has extremely few chances that the FET 115 is turned on, as described later.

  The intake pipe pressure sensor 207 is connected to the electronic control device 102 and outputs a result of the detected pressure to the electronic control device 102. The intake pipe pressure sensor 207 corresponds to the sensor 106 of the control target device 101 described above.

  Here, as an example of the failure detection of the actuator drive circuit 107 by the actuator drive circuit failure detection unit 111, an example of detecting a short-to-power fault will be described.

  As described above, since the electric load 105, the FET 115, and the current measuring device 116 are electrically connected in series between the power supply 103 and the ground 109, when the FET 115 is turned on, these connections are made conductive, and The electric load 105 is energized. Thus, the electric load 105 applies a driving force to the valve body of the turbocharger bypass valve 208 so as to open the turbocharger bypass valve 208.

  If the electric connection between the actuator drive circuit 107 and the electric load 105 is normal, the FET 115 is turned on to conduct electricity through the impedance of the electric load 105, so that the overcurrent is measured by the current measuring device 116. It will not be done. On the other hand, when a short-to-power fault occurs, even if the FET 115 is turned on, the current is supplied in a state where the impedance is substantially zero without passing through the impedance of the electric load 105, and thus the overcurrent is measured by the current measuring device. At this time, the overcurrent detection section 118 detects an overcurrent based on the current value measured by the current measuring device 116 and outputs the detection result to the actuator drive circuit failure detection section 111.

  The actuator drive circuit failure detection unit 111 determines whether or not an overcurrent is present based on the detection result input from the overcurrent detection unit 118. When it is determined that the current is an overcurrent, the actuator drive circuit failure detection unit 111 determines that a power supply fault has occurred and detects the power supply failure as a failure of the actuator drive circuit 107. On the other hand, when the current is not measured by the current measuring device 116 when the FET 115 is turned on, the actuator drive circuit failure detection unit 111 determines that there is no overcurrent. When the FET 115 is turned off, the current does not flow, so that the current is not measured by the current measuring device 116. Therefore, the actuator drive circuit failure detection unit 111 cannot determine whether a failure occurs in the actuator drive circuit 107 or not.

  When a short-to-power fault occurs, as described above, the FET on / off command unit 117 forcibly turns off the FET 115 in order to prevent damage to the circuit due to overcurrent. Further, in the electric load 105 at the time of occurrence of the short-to-power fault, no current flows because the voltage across the load is the same level as the power supply. Therefore, the turbocharger bypass valve 208 is fixed in a closed state.

  At this time, the actuator function abnormality detecting unit 110 detects that the turbocharger bypass valve 208 is closed and fixed as a function abnormality of the actuator 104.

  Hereinafter, control processing of the turbocharger bypass valve 208 by the electronic control device 102 will be described with reference to FIG. FIG. 3 is a flowchart showing a control process of the electronic control unit. The control process described in the flowchart of FIG. 3 is repeatedly executed at a cycle of, for example, 10 ms.

  First, in step S301, the actuator function abnormality detection unit 110 determines whether there is an actuator function abnormality. Here, the malfunction of the actuator 104 will be described with reference to the above-described closing of the turbocharger bypass valve 208.

  The cause of the occurrence of the sticking of the turbocharger bypass valve 208 due to the short-to-power failure of the actuator drive circuit 107 described above, as well as various factors such as clogging of the valve. It is ideal to directly check the open / closed state of the turbocharger bypass valve 208 in order to reliably determine whether or not there is a lock due to various factors including a short-to-power fault. It is difficult to directly monitor the open / closed state of the charger bypass valve 208. Therefore, the actuator function abnormality detection unit 110 indirectly determines whether or not the turbocharger bypass valve 208 is closed and fixed using the opening degree of the throttle valve 203, the detection result of the intake pipe pressure sensor 207, and the like.

  Hereinafter, a method of indirectly determining whether or not there is a lock will be described in detail with reference to FIG. FIG. 4 is a time chart related to the control processing of the electronic control unit. 4, the horizontal axis represents time, FIG. 4 (a) shows the open / closed state of the throttle valve 203, FIG. 4 (b) shows the detection signal of the intake pipe pressure sensor 207, and FIG. FIG. 4D is a circuit failure detection actuator control signal from the circuit failure detection actuator control unit 114, FIG. 4E is an actual operation of the turbocharger bypass valve 208, 4F shows a function abnormality counter signal of the actuator 104, FIG. 4G shows a failure counter signal of the actuator drive circuit 107, and FIG. 4H shows an actuator control switching signal from the actuator control switching unit 112.

  In the example shown in FIG. 4, it is assumed that a short-to-power fault occurs in the actuator drive circuit 107 at time t2. Therefore, after time t2, the turbocharger bypass valve 208 is fixed in the closed state regardless of the on / off switching of the FET 115. For example, at time t3, a command to turn on the FET 115 (that is, open the turbocharger bypass valve 208) is output by a normal actuator control signal (see FIG. 4C) from the normal actuator control unit 113. However, the actual operation of the turbocharger bypass valve 208 (see FIG. 4E) remains closed.

  During a normal period from time t1 to t2, the detection signal (see FIG. 4B) of the intake pipe pressure sensor decreases after the throttle valve 203 is fully closed in conjunction with the opening of the turbocharger bypass valve 208. Nevertheless, from time t2 to t4, it can be seen that no pressure drop has occurred in conjunction with the opening of the turbocharger bypass valve 208. Therefore, at time t3, a pressure exceeding the threshold value (see the dashed line in FIG. 4B) at which the pressure is determined to be abnormal by the intake pipe pressure sensor detection signal is detected.

  As described above, the actuator function abnormality detecting unit 110 determines whether the turbocharger bypass valve 208 is closed and fixed based on the open / closed state of the throttle valve 203, the open / closed state of the turbocharger bypass valve 208, and the detection result of the intake pipe pressure sensor 207. It can be indirectly determined whether there is.

  Further, in the present embodiment, in order to prevent erroneous detection due to the influence of electric noise or the like in the actuator drive circuit 107 and to determine that the close fixation determined by the above-described method has definitely occurred, The actuator function abnormality detecting unit 110 is configured to determine the final closed lock when the number of times of the event determined to be the closed lock exceeds a predetermined value. Specifically, as shown in FIG. 4 (f), when it is determined that the actuator is abnormally closed at time t3, the actuator function abnormality detection unit 110 counts up the actuator function abnormality counter and increases the number of times of the actuator function abnormality counter. It is further determined whether or not the value exceeds a predetermined value. Then, when it is determined that the number of times of the actuator function abnormality counter exceeds a predetermined value (see time t4 shown in FIG. 4F), the actuator function abnormality detection unit 110 determines the final closing fixation.

  In step S301 shown in FIG. 3, when the actuator function abnormality is determined as described above, the actuator function abnormality detection unit 110 determines that there is an actuator function abnormality, and performs a turbocharger bypass to make it easier to find the cause of the abnormality. An abnormality code corresponding to the valve 208 being closed and fixed is stored. Thereafter, the control process proceeds to step S303, and an abnormal time FET control signal is output. At this time, the actuator control switching unit 112 switches to the circuit failure detection actuator control unit 114 and outputs an actuator control switching signal shown in FIG. The switched circuit failure detection actuator control unit 114 outputs the circuit failure detection actuator control signal shown in FIG.

  As shown in FIG. 4D, the actuator control signal for detecting a circuit failure is output at the timing when the closing of the turbocharger bypass valve 208 is fixed (see FIG. 4F) (that is, at time t4). In order to detect a short-to-power fault at 107, an on / off signal is repeatedly output. That is, at this time, the central processing unit 108 controls the actuator drive circuit 107 so as to repeatedly switch between energization and non-energization of the turbocharger bypass valve 208.

  This circuit failure detection actuator control signal is turned on for a longer time than the normal actuator control signal shown in FIG. 4C, in other words, the number of times that the actuator 104 is energized is increased. It is possible to detect a short-circuit failure at an early stage.

  The actuator control signal for detecting a circuit failure is output so as to repeatedly turn on and off the FET 115 regardless of the controllability. However, the turbocharger bypass valve 208 remains closed (see FIG. 4E). Also, as shown in FIG. 4D, the reason for repeatedly outputting ON / OFF of the actuator control signal for detecting a circuit failure is to prevent heat generation due to continuous energization of the turbocharger bypass valve 208. Note that if the heat generation is within the allowable range, the control signal for ON only may be continuously output without repeatedly outputting ON / OFF of the control signal.

  On the other hand, if it is determined in step S301 that there is no abnormality in the actuator function, the control process proceeds to step S302, and a normal-time FET control signal is output. At this time, switching to the normal actuator control unit 113 is performed by the actuator control switching unit 112, and the switched normal actuator control unit 113 outputs the normal actuator control signal shown in FIG. 4C. As described above, the normal-state actuator control signal is used to release the excess pressure in the intake pipe 202 due to the full-close operation of the throttle valve 203 and to prevent an excessive load from being applied to the throttle valve 203 and the turbocharger 206. This is the output signal.

  In step S304 following steps S302 and S303, the actuator drive circuit failure detection unit 111 determines whether the actuator drive circuit failure has been determined. More specifically, the actuator drive circuit failure detection unit 111 makes the determination based on the result of the determination of the circuit failure in step S312 described below. Then, when it is determined that the actuator drive circuit failure has been determined, the control process proceeds to step S306. In step S306, the FET on / off command unit 117 forcibly turns off the FET 115 irrespective of the detection of the overcurrent. As a result, it is possible to prevent the actuator drive circuit 107 from being damaged or fired due to a short-to-power fault, and to protect the actuator drive circuit 107. Then, when step S306 ends, a series of processing ends.

  On the other hand, if it is determined in step S304 that the actuator drive circuit failure has not been determined, the control process proceeds to step S305. In step S305, the actuator drive circuit failure detection unit 111 determines whether the FET 115 is on. When it is determined that the FET 115 is not on (in other words, the FET 115 is off), a series of processing ends. On the other hand, if it is determined that the FET 115 is on, the control process proceeds to step S307.

  In step S307, the actuator drive circuit failure detection unit 111 determines whether or not the current is an overcurrent based on the current value detected via the current measuring device 116 and the overcurrent detection unit 118. If it is determined that the current is not an overcurrent, the control process proceeds to step S308, and the actuator drive circuit failure detection unit 111 clears the actuator drive circuit failure counter. When step S308 ends, a series of processing ends.

  On the other hand, if it is determined in step S307 that the current is an overcurrent, the actuator drive circuit failure detection unit 111 determines that the power supply failure has occurred while detecting the power supply failure as a circuit failure. Thereafter, the control processing proceeds to step S309. In step S309, the FET on / off command unit 117 turns off the FET 115 from the end of the control processing shown in FIG. By turning off the FET 115 in this manner, it is possible to prevent the actuator drive circuit 107 from being damaged due to continuous overcurrent flowing.

  In step S310 following step S309, the actuator drive circuit failure detection unit 111 counts up the number of counters for determining the actuator drive circuit failure. In the present embodiment, in order to prevent erroneous detection due to the influence of noise or the like as in the case of the above-described actuator function abnormality, and to surely determine that a circuit failure has occurred, the actuator drive circuit failure detection unit 111 If the number of events determined to be current exceeds a predetermined value, a final short-to-power fault is determined. The counter signal for determining the actuator drive circuit failure is as shown in FIG.

  In step S311, following step S310, the actuator drive circuit failure detection unit 111 determines whether the number of circuit failure counters exceeds a predetermined value. When it is determined that the number of times of the counter does not exceed the predetermined value, a series of processing ends. On the other hand, when it is determined that the number of times of the counter exceeds the predetermined value, the control process proceeds to step S312, and the actuator drive circuit failure detection unit 111 finally determines the actuator drive circuit failure. Then, when step S312 ends, a series of control processing ends.

  Hereinafter, the determination of the actuator drive circuit failure (here, short-to-supply fault) in the above-described control processing will be described in chronological order with reference to a time chart shown in FIG.

  In the above-described control processing, it is assumed that a short-to-power fault occurs at time t2, and the FET 115 is turned off at time t2 as indicated by the normal-state actuator control signal in FIG. 4C. For this reason, since it is determined in step S305 that the FET is not on, the processing after step S307 is not executed, and the control processing ends. In this case, as the actuator drive circuit failure counter signal (see FIG. 4G), the value at the end of the previous control processing is continuously adopted.

  Next, at time t3, as indicated by the normal-state actuator control signal, the FET 115 is turned on at short intervals (see FIG. 4C). For this reason, the FET 115 is determined to be on in step S305 described above, and the overcurrent is determined in step S307, so that the processes in step S309 and thereafter are executed. At time t3, the counter of the circuit failure indicated by the actuator drive circuit failure counter signal slightly increases, but since the time during which the FET 115 is turned on is short, it does not lead to the determination of the short-to-power fault.

  Next, at time t4, since it is determined in step S301 that there is an actuator function abnormality, as shown by the actuator control switching signal (see FIG. 4H), the circuit failure detection actuator control unit 114 Switching is performed, and in step S303, a circuit failure detection actuator control signal is output as a pulse (see FIG. 4D). Since the circuit failure detection actuator control signal is turned on more frequently than the normal-state actuator control signal (see FIG. 4C), the circuit failure between the times t4 and t5 is smaller than that between the times t3 and t4. Counter rises faster.

  Next, at time t5, it is determined in step S311 that the actuator drive circuit failure counter signal (see FIG. 4G) has exceeded a predetermined value, and finally in step S312, a short-to-power fault is determined. When the short-to-power fault is determined, the actuator drive circuit fault detecting unit 111 stores a fault code corresponding to the short-to-power fault so that the fault code can be easily confirmed when the cause of the fault is determined.

  Further, the electronic control device 102 of the present embodiment further has a self-diagnosis function for determining whether or not the cause is a circuit failure when a malfunction of the actuator occurs. Specifically, the electronic control unit 102 performs a self-diagnosis by determining that the cause of the above-described closed fixation is due to a short-to-power fault and not due to damage to the turbocharger bypass valve 208 itself or clogging of the valve. .

  Then, when it is determined that the cause of the lock is due to a short-to-power fault, the actuator function abnormality detection unit 110 withdraws the previously stored abnormality code of the lock of the turbocharger bypass valve 208 that has already been stored. To withdraw here means to delete the memorized closing of the turbocharger bypass valve 208. Then, by withdrawing the function abnormality detected by the actuator function abnormality detection unit 110 in this way, it is possible to clarify the failure of the actuator drive circuit 107 which is the cause of the function abnormality. It can be easier.

  As described above, the electronic control device 102 of the present embodiment includes the actuator drive circuit 107 that switches between energization and non-energization of the actuator 104, and the central processing unit 108 that controls the actuator 104 and the actuator drive circuit 107. It is. In addition, the central processing unit 108 includes an actuator function abnormality detection unit 110 that detects a function abnormality of the actuator 104. When the function abnormality of the actuator 104 is detected by the actuator function abnormality detection unit 110, the central processing unit 108 preferably controls the actuator drive circuit 107 so as to switch between energization and non-energization of the actuator 104. Further, the central processing unit 108 preferably includes an actuator drive circuit failure detection unit 111 that detects a failure of the actuator drive circuit 107 when the actuator drive circuit 107 switches between energization and non-energization of the actuator 104. .

  More specifically, as described above, when the actuator function abnormality detection unit 110 detects that the turbocharger bypass valve 208 is closed and closed, the central processing unit 108 switches the energization and non-energization of the actuator 104 By controlling the drive circuit 107, the chance of energizing the actuator 104 can be increased. This makes it possible to detect a failure of the actuator drive circuit 107 at an early stage, even when the energization to the actuator 104 is small.

  Further, when the function abnormality of the actuator 104 is detected by the actuator function abnormality detection unit 110, the central processing unit 108 preferably controls the actuator drive circuit 107 so as to repeatedly switch between energization and non-energization of the actuator 104. . This makes it possible to detect a short-to-power fault of the actuator drive circuit 107 earlier, and to prevent heat generation due to continuous energization of the turbocharger bypass valve 208 (that is, the actuator 104).

  When the actuator drive circuit failure detection unit 111 detects a circuit failure, it is desirable that the actuator drive circuit 107 de-energizes the actuator 104. Specifically, as described in step S309, when a short-to-supply fault is detected by the actuator drive circuit fault detection unit 111, the FET on / off command unit 117 turns off the FET 115 to de-energize the actuator 104. To This can prevent the actuator drive circuit 107 from being damaged due to continuous overcurrent.

  Further, when a circuit failure is detected by the actuator drive circuit failure detection section 111, the actuator function abnormality detection section 110 desirably withdraws the function abnormality detected by the actuator function abnormality detection section 110. Specifically, as described above, when a short-to-power fault is detected by the actuator drive circuit failure detection unit 111, the actuator function abnormality detection unit 110 withdraws the previously detected and stored closed-stuck abnormality code. By doing so, it is possible to clarify the failure of the actuator drive circuit 107, which is the cause of the malfunction, so that it is possible to find the cause more quickly and easily.

  Furthermore, this makes it possible to quickly implement protection measures according to the failure mode when a circuit failure occurs, and to reduce the number of repair man-hours in the aftermarket after the failure based on the stored failure code. Become. Further, by clarifying the failure of the actuator drive circuit 107 which causes the functional abnormality in this way, it is possible to prevent erroneous replacement of a component that has not failed.

  The actuator 104 is preferably the turbocharger bypass valve 208 of the vehicle internal combustion engine 201. This makes it possible to detect a failure of the turbocharger bypass valve 208 at an early stage even if the turbocharger bypass valve 208 has an extremely small chance of the FET 115 being turned on.

  In the present embodiment, an example in which a short-to-power fault is detected as an example of fault detection of the actuator drive circuit 107 has been described. However, the present invention relates to detection of disconnection of electrical connection and detection of a ground fault in the actuator drive circuit 107. Also applicable to

  That is, it is desirable that the actuator drive circuit failure detection unit 111 detects a disconnection of the electrical connection of the actuator drive circuit 107. As shown in FIG. 1, the FET 115 is connected to a power supply 120 via a pull-up resistor 119 and a diode 121, and the power supply voltage of the power supply 120 (here, 2.5 V) is applied to the pull-up resistor 119. Has become. In a state where the electric connection between the FET 115 and the power supply 103 is not broken, when the FET 115 is off, the FET 115 is connected to the power supply 103, so that the potential at the point A shown in FIG. The potential is 103 (here, 15 V). On the other hand, when the electric connection is broken between the FET 115 and the power supply 103 (in other words, when the electric connection of the actuator drive circuit 107 is broken), the FET 115 is connected to the power supply 103 in a state where the FET 115 is turned off. Since there is no potential, a potential of 2.5 V is input to the point A by the pull-up resistor 119. Therefore, by measuring the potential at the point A, it is possible to detect whether or not the electrical connection in the actuator drive circuit 107 is broken based on the value of the measured potential. In this way, disconnection of the electrical connection in the actuator drive circuit 107 can be detected at an early stage.

  Further, it is desirable that the actuator drive circuit failure detection unit 111 detects a ground fault of the actuator drive circuit 107. In the case of a ground fault, the portion connected to the power supply 103 is connected to the side of the ground 109, so that the FET 115 is de-energized, so that the potential at the point A becomes 0V. The ground fault can be detected based on this. In this way, a ground fault of the actuator drive circuit 107 can be detected early.

  As mentioned above, although one Embodiment of this invention was described in detail, this invention is not limited to said Embodiment. In addition, each component is not limited to the above configuration as long as the characteristic function of the present invention is not impaired. For example, in the above-described embodiment, the example in which the actuator 104 is the turbocharger bypass valve 208 has been described. However, the present invention is also applied to valves other than the turbocharger bypass valve 208.

REFERENCE SIGNS LIST 100 Control system 101 Control target device 102 Electronic control device 103 Power supply 104 Actuator 105 Electric load 106 Sensor 107 Actuator drive circuit 108 Central processing unit 109 Ground 110 Actuator function abnormality detection unit 111 Actuator drive circuit failure detection unit 112 Actuator control switching unit 113 Normal actuator control unit 114 Circuit failure detection actuator control unit 115 FET
116 Current measuring instrument 117 FET on / off command section 118 Overcurrent detecting section 119 Pull-up resistor 120 Power supply 121 Diode 201 Vehicle internal combustion engine 202 Intake pipe 203 Throttle valve 204 Cylinder 205 Exhaust pipe 206 Turbocharger 207 Intake pipe pressure sensor 208 Turbocharger Bypass valve

Claims (9)

An actuator drive circuit for switching between energization and non-energization of the actuator,
A central processing unit that controls the actuator and the actuator drive circuit,
The central processing unit,
An actuator function abnormality detection unit for detecting a function abnormality of the actuator, wherein the actuator drive unit switches between energization and non-energization of the actuator when the actuator function abnormality detection unit detects a function abnormality of the actuator. An electronic control unit that controls the circuit.   2. The actuator according to claim 1, wherein the central processing unit includes an actuator drive circuit failure detection unit that detects a failure of the actuator drive circuit when the actuator drive circuit switches between energization and non-energization of the actuator. 3. Electronic control unit.   3. The actuator according to claim 2, wherein the central processing unit controls the actuator drive circuit so as to repeatedly switch between energization and non-energization of the actuator when the actuator function abnormality detection unit detects a function abnormality of the actuator. Electronic control unit.   4. The electronic control device according to claim 2, wherein the actuator drive circuit de-energizes the actuator when a circuit failure is detected by the actuator drive circuit failure detection unit. 5.   The method according to any one of claims 2 to 4, wherein when the actuator drive circuit failure detection unit detects a circuit failure, the actuator function abnormality detection unit cancels the function abnormality detected by the actuator function abnormality detection unit. Electronic control unit.   The electronic control device according to any one of claims 2 to 5, wherein the actuator drive circuit failure detection unit detects a power supply failure of the actuator drive circuit.   The electronic control device according to any one of claims 2 to 5, wherein the actuator drive circuit failure detection unit detects a disconnection of an electrical connection of the actuator drive circuit.   The electronic control device according to claim 2, wherein the actuator drive circuit failure detection unit detects a ground fault of the actuator drive circuit.   The electronic control device according to claim 1, wherein the actuator is a turbocharger bypass valve of a vehicle internal combustion engine.

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