JP2019183701A - ECU and exhaust brake control device - Google Patents

Abstract

To provide an electronic control device and an exhaust brake control device capable of efficiently diagnosing effectiveness at a signal line of redundancy in reference to a vehicle operation.SOLUTION: ECU (30) for cutting off a control signal (S1) in respect to an exhaust flap (19) in reference to a first signal (S41A) and a second signal (S51A) that are redundancy and operating the exhaust flap (19) to its opened position is constituted in such a way that CPU (31) of ECU (30) comprises a first processing part (311) for controlling an opening or closing operation of the exhaust flap (19), shuts off the control signal (S1) in reference to a first signal (S41A) got from the first processing part (311), then shuts off the control signal (S1) on the basis of a second signal (S51A) and judges effectiveness of redundancy in reference to a real opened position of each of the exhaust flaps (19) when it is shut off.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ECU and an exhaust brake control device, and is particularly suitable for application to a vehicle equipped with a diesel engine.

  In general, a vehicle equipped with a diesel engine includes an exhaust flap in an exhaust pipe. The exhaust flap operates in an open position for opening the exhaust pipe or a closed position for closing the exhaust pipe under the control of an electronic control unit (ECU).

  When the exhaust flap is moved to the closed position where the exhaust pipe is closed, the exhaust pressure in the exhaust pipe increases, so that the rotational resistance of the engine increases and the action of the engine brake is improved. A brake that closes the exhaust flap and improves the action of the engine brake is generally called an exhaust brake.

  Patent Document 1 discloses a technique related to an exhaust brake. Specifically, an exhaust brake is disclosed in which a hole is formed in a butterfly valve (exhaust flap) to ensure a constant exhaust flow rate even when the exhaust flap is in a fully closed position. According to the technique described in Patent Document 1, it is possible to reduce the cost required for managing the exhaust flow rate.

JP 2011-69321 A

  By the way, if the exhaust flap is unintentionally operated due to a malfunction or disconnection of the ECU, the engine brake is too effective depending on the road surface condition, and slip occurs. In this case, it is necessary to return the exhaust flap to the open position in order to ensure the safety of the vehicle. However, if there is any malfunction in the ECU or signal line, the exhaust flap may not be reliably moved to the open position.

  In such a case, as a method for surely operating the exhaust flap to the open position, for example, a method of duplicating the signal line for operating to the open position is conceivable.

  However, even if the signal lines are simply doubled, if one or both of the signal lines are defective, such as disconnection, it cannot be said that they are actually redundant, and the exhaust flap is reliably operated to the open position. I can't let you. Therefore, in order to realize redundancy, it is necessary to appropriately diagnose the doubled signal lines. It is desirable that the diagnosis be performed efficiently in consideration of vehicle operation.

  The present invention has been made in view of the above points, and proposes an electronic control device and an exhaust brake control device capable of efficiently diagnosing the effectiveness of redundant signal lines in consideration of vehicle operation. .

  In order to solve such a problem, in the present invention, the control signal (S1) for the exhaust flap (19) is shut off based on the redundant first signal (S41A) and second signal (S51A), In the ECU (30) that moves the exhaust flap (19) to the open position, the CPU (31) of the ECU (30) includes a first processing unit (311) that controls the opening / closing operation of the exhaust flap (19). The control signal (S1) is cut off based on the first signal (S41A) from the first processing unit (311) at the timing when the vehicle is not traveling, and then based on the second signal (S51A). The control signal (S1) is cut off, and the effectiveness of redundancy is determined based on the actual open position of each exhaust flap (19) when the control signal (S1) is cut off.

  According to the present invention, it is possible to efficiently diagnose the effectiveness of redundant signal lines in consideration of vehicle operation.

1 is an overall configuration diagram of an intake system and an exhaust system of a vehicle. It is an internal block diagram of an exhaust-brake control apparatus. It is an internal block diagram of ECU. It is a flowchart of a redundancy diagnosis process. It is an internal block diagram of another exhaust-brake control apparatus.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The following description is merely an embodiment of the present invention, and the technical scope of the present invention is not limited to this.

FIG. 1 shows the overall configuration of the intake system and exhaust system of the vehicle 1.
The intake system includes an intake pipe 11, a compressor 12 a, an intercooler 13, and an intake manifold 14. The intake air i passes through the intake pipe 11, is compressed by the compressor 12 a, is cooled by the intercooler 13, and is distributed to each cylinder by the intake manifold 14. The intake air i distributed to each cylinder is mixed with the fuel injected from the injector 15 and burned in the combustion chamber of each cylinder.

  The exhaust system includes an exhaust manifold 16, an exhaust pipe 17, an exhaust gas recirculation (EGR) device 18, a turbine 12b, an exhaust flap 19, and an exhaust purification device 20. The exhaust e discharged from the combustion chamber of each cylinder is integrated by the exhaust manifold 16 and then branched into exhaust flowing in the direction of the EGR device 18 and exhaust flowing in the direction of the turbine 12b through the exhaust pipe 17.

  The exhaust e flowing in the direction of the EGR device 18 passes through the EGR pipe 18a, is cooled by the EGR cooler 18b, the flow rate is adjusted by the EGR valve 18c, and is again distributed to each cylinder by the intake manifold 14. Exhaust gas e distributed to each cylinder is reused for combustion.

  On the other hand, the exhaust e that is not reused for combustion flows in the direction of the turbine 12b. The exhaust e rotates the compressor 12a connected to the turbine 12b via the turbine 12b. As a result of the intake air i being compressed by the rotational drive of the compressor 12a, combustion in the combustion chamber is promoted. The compressor 12a and the turbine 12b are generally referred to as a turbocharger 12.

  The flow rate of the exhaust e that has passed through the turbine 12 b is adjusted by the exhaust flap 19. Although details of the operation of the exhaust flap 19 will be described later, the exhaust flap 19 operates in the open position during normal operation, and operates in the closed position during exhaust brake operation. The exhaust e whose flow rate is adjusted by the exhaust flap 19 passes through the exhaust purification device 20 and is then discharged to the outside.

  The exhaust purification device 20 includes a DPF (Diesel Particulate Filter) device 20a and a urea SCR (Selective Catalytic Reduction) device 20b. The DPF device 20a collects and removes particulate matter contained in the exhaust e. The urea SCR device 20b reduces nitrogen oxides contained in the exhaust gas e to nitrogen or water vapor that is harmless to the human body using an aqueous urea solution.

The vehicle 1 also includes an exhaust brake control device 100.
The exhaust brake control device 100 includes an electronic control unit (ECU) 30, a relay 40, an external ECU 50, and an exhaust flap 19.

  The ECU 30 receives signals from various sensors (not shown) installed in each part of the vehicle 1 and transmits control signals to various devices (not shown) installed in each part of the vehicle 1. The operation of the vehicle 1 is comprehensively controlled.

  In particular, here, the ECU 30 transmits a control signal S <b> 1 via the relay 40 to an actuator (not shown) that operates the exhaust flap 19. As a result, the ECU 30 can normally move the exhaust flap 19 in the open position to the closed position during the exhaust brake operation. The closed position includes an intermediate position where the exhaust pipe 17 is partially closed and a fully closed position where the exhaust pipe 17 is entirely closed.

  ECU 30 is connected to relay 40 through a signal line different from the signal line for transmitting control signal S1. The ECU 30 transmits a cutoff signal S4 to the relay 40 when blocking the control signal S1. As a result, the relay 40 operates and the exhaust flap 19 can be moved to the open position regardless of whether or not the control signal S1 is transmitted.

  The exhaust flap 19 includes a spring member such as a return spring (not shown), and maintains the open position by the action of the spring force of the return spring during normal times when the control signal S1 is not transmitted. On the other hand, the exhaust flap 19 operates to the closed position against the spring force of the return spring during the exhaust brake operation in which the control signal S1 is transmitted.

  The exhaust flap 19 includes a position sensor (not shown), and transmits a position signal S2 indicating an open position or a closed position to the ECU 30. The ECU 30 appropriately controls the operation of the exhaust flap 19 based on the position signal S2.

  The relay 40 is disposed between the ECU 30 and the exhaust flap 19 and connects the ECU 30 and the exhaust flap 19 so that they can communicate with each other. The relay 40 is connected to the ECU 30 and the exhaust flap 19 by an independent signal line different from the signal line between the ECU 30 and the exhaust flap 19. Under the control of the ECU 30, the relay 40 operates to make the signal line conductive during normal operation and transmit the control signal S <b> 1, while blocking the signal line during slipping.

  The external ECU 50 is an ECU in a separate housing from the ECU 30, and is specifically an ABS (Antilock Brake System) device or an ESP (Electronic Stability Control) device. When the external ECU 50 detects a slip of the vehicle 1, it generates a slip detection signal S <b> 3 and transmits it to the ECU 30. When the ECU 30 receives the slip detection signal S3, the ECU 30 transmits a shut-off signal S4, and shuts off the control signal S1 to move the exhaust flap 19 to the open position.

FIG. 2 shows the internal configuration of the exhaust brake control device 100.
The exhaust brake control device 100 includes the ECU 30, the relay 40, the external ECU 50, and the exhaust flap 19 as described above. The ECU 30 includes a CPU (Central Processing Unit) 31, an H bridge circuit 32, and a switch circuit 33.

  The CPU 31 comprehensively controls the operation of the ECU 30. Here, in order to control the operation of the exhaust flap 19, the CPU 31 receives the position signal S2 from the exhaust flap 19, and if the opening / closing position of the exhaust flap 19 is to be controlled based on the position signal S2, the CPU 31 sends the signal to the H bridge circuit 32. A control request signal S11 is transmitted.

  Further, the CPU 31 transmits a cutoff request signal S41 to the H-bridge circuit 32 when it is necessary to move the exhaust flap 19 to the open position regardless of the position signal S2 (regardless of the opening / closing position of the exhaust flap 19). A cutoff request signal S51 is transmitted to the switch circuit 33.

  The H bridge circuit 32 transmits a control signal S1 for controlling the opening / closing position of the exhaust flap 19 based on the control request signal S11 from the CPU 31. The control signal S1 is transmitted to an actuator (not shown) via the relay 40. Based on the control signal S1, the actuator moves the exhaust flap 19 to the closed position when it is in the open position.

  The H bridge circuit 32 transmits to the relay 40 a cutoff signal S4 for controlling the operation of the relay 40 based on the cutoff request signal S41 from the CPU 31. In this case, the relay 40 blocks the signal line connecting the ECU 30 (H bridge circuit 32) and the exhaust flap 19 regardless of whether or not the control signal S1 is transmitted, and controls from the H bridge circuit 32. The signal S1 is cut off. As a result, the exhaust flap 19 is moved to the open position by the action of the spring force of the return spring.

  Actually, the H-bridge circuit 32 includes a high-side switch, and when the high-side switch receives the cutoff request signal S41 from the CPU 31, it is turned on and a current flows through the coil of the relay 40. When a current flows through the coil, the relay 40 operates to cut off the control signal S1.

  The switch circuit 33 is a circuit different from the H bridge circuit 32 and is connected to the CPU 31 and the relay 40 through a path independent of the H bridge circuit 32.

  The switch circuit 33 controls the operation of the relay 40 based on the cutoff request signal S51 from the CPU 31. Regardless of whether or not the control signal S1 is transmitted, the relay 40 cuts off the signal line connecting the ECU 30 (H bridge circuit 32) and the exhaust flap 19 and receives the control signal S1 from the H bridge circuit 32. Cut off. As a result, the exhaust flap 19 is moved to the open position by the action of the spring force of the return spring.

  Actually, the switch circuit 33 is, for example, a low-side switch. When the low-side switch receives the cutoff request signal S51 from the CPU 31, the low-side switch is turned on, and a current flows through the coil of the relay 40. When a current flows through the coil of the relay 40, the relay 40 operates to cut off the control signal S1.

  The external ECU 50 is an ECU that detects a slip of the vehicle 1 and is, for example, ABS or ESP. When detecting the slip of the vehicle 1, the CPU 51 of the external ECU 50 transmits a slip detection signal S <b> 3 to the CPU 31. When receiving the slip detection signal S3, the CPU 31 generates a cutoff request signal S41 or S51 and transmits it to the H bridge circuit 32 or the switch circuit 33. Thereby, the control signal S1 from the H bridge circuit 32 can be cut off.

  FIG. 3 shows the internal configuration of the ECU 30. The ECU 30 includes the CPU 31, the H bridge circuit 32, and the switch circuit 33 as described above. Here, in particular, the internal configuration of the CPU 31 will be described.

The CPU 31 includes three processing areas of levels 1 to 3.
Level 1 is a processing area that substantially controls the opening / closing operation of the exhaust flap 19, and includes a first processing unit 311. The first processing unit 311 transmits a control request signal S 11 to the H bridge circuit 32, and controls the opening / closing operation of the exhaust flap 19 via the H bridge circuit 32.

  Further, when the first processing unit 311 receives the slip detection signal S3 from the external ECU 50, the first processing unit 311 detects that a slip has occurred in the vehicle 1. In this case, the first processing unit 311 generates a blocking request signal S41A or S51A based on the slip detection signal S3 and transmits it to the H bridge circuit 32 or the switch circuit 33.

  Level 2 is a processing area for monitoring level 1 processing, and includes a second processing unit 312. When the second processing unit 312 receives the slip detection signal S3 from the external ECU 60, the second processing unit 312 detects that the vehicle 1 has slipped. In this case, the second processing unit 312 generates a blocking request signal S61A based on the slip detection signal S3, and transmits this to the first processing unit 311.

  Even if the first processing unit 311 has not received the slip detection signal S3 to be received, or has not generated the blocking request signal S41A or S51A to be generated based on the slip detection signal S3, the first processing unit 311 A cutoff request signal S41A or S51A is generated based on the cutoff request signal S61A from the second processing unit 312 and transmitted to the H bridge circuit 32 or the switch circuit 33.

  As a result, even if a partial malfunction occurs in the first processing unit 311 or a malfunction occurs in the connection between the first processing unit 311 and the external ECU 50, the vehicle 1 When slip occurs, the exhaust flap 19 can be reliably moved to the open position.

  In addition, the second processing unit 312 monitors the presence / absence of the blocking request signal S41A or S51A from the first processing unit 311, and despite having transmitted the blocking request signal S61A to the first processing unit 311, When the cutoff request signal S41A or S51A is not transmitted from the first processing unit 311, the cutoff request signal S61B is generated and transmitted to the third processing unit 313.

  Level 3 is a processing area for monitoring level 2 processing, and includes a third processing unit 313. When the third processing unit 313 receives the cutoff request signal S61B from the second processing unit 312, the third processing unit 313 generates a cutoff request signal S41B or S51B and transmits it to the H bridge circuit 32 or the switch circuit 33.

  As a result, when the malfunction occurs in the first processing unit 311 and the shutoff request signal S41A or S51A is not transmitted and the vehicle 1 slips, the exhaust flap 19 is reliably operated to the open position. Can be made.

  FIG. 4 shows a flowchart of the redundancy diagnosis process. The redundancy diagnosis process is a process for determining the effectiveness of redundancy, and specifically is a process for determining the effectiveness of the blocking request signal S41A and the blocking request signal S51A by the first processing unit 311. Hereinafter, the CPU 31 of the ECU 30 will be described as a processing subject.

  First, the CPU 31 determines whether or not it is a timing when the vehicle 1 is not traveling (SP1). The timing when the vehicle 1 is not traveling is, for example, the timing when a series of driving cycles from when the ignition is turned on and the engine is started to when the ignition is turned off and the engine is stopped are finished.

  Processing performed at the timing just before the end of the driving cycle is called an after-run process. The more detailed timing of the after-run process is the timing from when the ignition is turned off until the power of the ECU 30 is turned off.

  Here, it is assumed that the redundancy diagnosis process is executed in the after-run process. However, the present invention is not limited to this, and it may be any timing when the vehicle 1 is not traveling. For example, the vehicle 1 waits for a signal. The timing may be.

  When the CPU 31 obtains a negative result in the determination at step SP1 (SP1: N), it determines whether it is a timing when the vehicle 1 is not continuously running. On the other hand, when the CPU 31 obtains a positive result in the determination at step SP1 (SP1: Y), the CPU 31 blocks the control signal S1 based on the blocking request signal S41A from the first processing unit 311 (SP2).

  Specifically, the CPU 31 generates a control request signal S11 in the first processing unit 311 and transmits the control request signal S11 to the H bridge circuit 32 to temporarily move the exhaust flap 19 to the closed position. This is for securing a reference position (for example, a position where the opening degree is 0%).

  Thereafter, the CPU 31 generates a cutoff request signal S41A in the first processing unit 311 and transmits it to the H bridge circuit 32 to cut off the control signal S1.

  Based on the position signal S2 from the exhaust flap 19, the CPU 31 determines whether or not the exhaust flap 19 has actually moved to the open position (SP3). When determining whether or not it has moved to the open position, the CPU 31 determines that it has moved to the open position when a certain amount of opening operation has been confirmed (for example, when the opening degree has changed from 0% to 10%). .

  Thus, by making a determination when the exhaust flap 19 moves in the opening direction even a little, the diagnosis time can be shortened.

  Next, when the CPU 31 obtains a positive result in the determination at step SP3 (SP3: Y), the CPU 31 shuts off the control signal S1 based on the shut-off request signal S51A from the first processing unit 311 (SP4), and the exhaust flap 19 It is determined whether or not it has moved to the open position (SP5). Since the processing contents in steps SP4 and SP5 are the same as those in steps SP2 and SP3 described above, description thereof will be omitted.

  When the CPU 31 obtains a positive result in the determination at step SP5 (SP5: Y), it determines that redundancy is effective (SP6), and ends this process.

  On the other hand, if the CPU 31 obtains a negative result in the determination at step SP3 or SP5 (SP3: N, SP5: N), it determines that the redundancy is not effective (SP7), and ends this process. When it is determined that redundancy is not effective, for example, an error display may be performed.

  FIG. 5 shows an internal configuration of another exhaust brake control device 100B. 2 is different from the exhaust brake control device 100 of FIG. 2 in that the high side switch 34 and the low side switch 35 are provided and the relay 40 is not provided. Hereinafter, the same components as those in the exhaust brake control device 100 are denoted by the same reference numerals, description thereof is omitted, and different points will be described.

  The high side switch 34 and the low side switch 35 transmit a control signal S1 for controlling the opening / closing position of the exhaust flap 19 based on a control request signal S11 from the CPU 31. An actuator (not shown) is operated by the control signal S1, and the exhaust flap 19 is moved to the closed position.

  The high-side switch 34 and the low-side switch 35 switch the internal switches to OFF based on the cutoff request signals S61 and S71 from the CPU 31. Accordingly, the high side switch 34 and the low side switch 35 can block the signal line connected to the exhaust flap 19 and block the control signal S <b> 1 for the exhaust flap 19.

  When the signal line connected to the exhaust flap 19 is cut off, the high side switch 34 and the low side switch 35 transmit a response signal S81 indicating this cut-off state (open load) to the CPU 31. The CPU 31 determines that the exhaust flap 19 has actually moved to the open position based on the response signal S81. The diagnosis time can be shortened by determining the opening operation based on the response signal S81 indicating the open road.

  As described above, according to the present embodiment, the validity of the redundant cutoff request signal S41A and cutoff request signal S51A is determined at the timing when the vehicle 1 is not traveling. Further, when the exhaust flap 19 has moved in the opening direction even a little, or when it is predicted to operate in the opening direction, it is determined that the exhaust flap 19 has actually moved to the open position. In this case, redundancy is effective. Judgment was made. As a result, the effectiveness of the redundant signal lines can be efficiently diagnosed.

1 Vehicle 19 Exhaust flap 30 ECU
32 H bridge circuit 33 Switch circuit 31 CPU
311 First processing unit 312 Second processing unit 313 Third processing unit 40 Relay 50 External ECU
100 exhaust brake control device S1 control signal S11 control request signal S4 shut-off signal S41 shut-off request signal S51 shut-off request signal

Claims (6)

An ECU that cuts off the control signal (S1) for the exhaust flap (19) based on the redundant first signal (S41A) and second signal (S51A), and moves the exhaust flap (19) to the open position. (30)
The CPU (31) of the ECU (30)
A first processing unit (311) for controlling the opening / closing operation of the exhaust flap (19);
At a timing when the vehicle is not traveling, the control signal (S1) is cut off based on the first signal (S41A) from the first processing unit (311), and then the second signal (S51A). The control signal (S1) is cut off based on the ECU, and the effectiveness of redundancy is determined based on the actual open position of each exhaust flap (19) when the control signal (S1) is cut off. ). The CPU (31)
2. The ECU according to claim 1, wherein an after-run process timing from when the ignition is turned off until the ECU (30) is turned off is determined as a timing when the vehicle is not traveling. 30). The CPU (31)
Determining the actual open position of the exhaust flap (19) based on a position signal (S2) indicating the actual position of the exhaust flap (19) or a response signal (S81) indicating an open road. ECU (30) according to claim 1 or 2, characterized in that The CPU (31)
After the exhaust flap (19) is once moved to the closed position by the control signal (S1), the control signal (S1) is cut off by the first signal (S41A) or the second signal (S51A). The ECU (50) according to any one of claims 1 to 3, characterized in that. The CPU (31)
A second processing unit (312) for monitoring the first processing unit (311);
5. A third processing unit (313) that controls an opening / closing operation of the exhaust flap (19) based on an instruction from the second processing unit (312). The ECU (50) according to claim 1. An ECU that cuts off the control signal (S1) for the exhaust flap (19) based on the redundant first signal (S41A) and second signal (S51A), and moves the exhaust flap (19) to the open position. In the exhaust brake control device (100) provided with (30),
The CPU (31) of the ECU (30)
A first processing unit (311) for controlling the opening / closing operation of the exhaust flap (19);
At a timing when the vehicle is not traveling, the control signal (S1) is cut off based on the first signal (S41A) from the first processing unit (311), and then the second signal (S51A). The control signal (S1) is cut off based on the exhaust brake control, and the effectiveness of redundancy is judged based on the actual open position of each exhaust flap (19) when the control signal (S1) is cut off. Device (100).

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