JP2910510B2 - Electronic throttle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic throttle control device, that is, a throttle valve based on a result of detecting an operation amount of an accelerator pedal and electronically calculating the detected value and various state signals of a vehicle. The present invention relates to a device for controlling an opening, and more particularly to a fail-safe technique.

[0002]

2. Description of the Related Art As a conventional electronic throttle control device, for example, there is one disclosed in Japanese Patent Application Laid-Open No. Hei 2-30933 or Japanese Patent Application Laid-Open No. 2-201037. this is,
It has a normally closed first electromagnetic clutch that is connected when non-energized, and a normally open second electromagnetic clutch that is non-connected when non-energized. A throttle mechanically connected to a clutch and a second electromagnetic clutch, a motor is mechanically connected to the other end of the second electromagnetic clutch, and an accelerator pedal is mechanically connected to the other end of the first electromagnetic clutch. It has an actuator. In a throttle control module (TCM) composed of a microcomputer, the throttle valve opening is calculated and an abnormality is determined in accordance with the operation amount of the accelerator pedal, the vehicle speed, and the like. Thus, the first electromagnetic clutch is disconnected and the second electromagnetic clutch is connected, and the throttle valve is controlled to be opened and closed by a motor. In the event of an abnormality, both electromagnetic clutches are de-energized. Clutch engaged,
The second electromagnetic clutch is disengaged, and the throttle valve is directly opened and closed by an accelerator pedal. In this conventional example, the throttle valve is opened and closed by the motor in a normal state, but if any failure occurs, the two electromagnetic clutches are turned off to open the throttle valve and the motor, and the throttle valve is opened. The valve and the accelerator pedal are mechanically connected. Therefore, in this device, even in the event of a failure, there is no fear that the engine rotation speed will increase against the driver's will, and traveling according to the accelerator operation can be maintained.

[0003]

However, in the conventional control system as described above, fail-safe control is performed by controlling the drive circuit of the electromagnetic clutch and the motor only by the throttle control module. Therefore, if a signal line from each sensor input to the throttle control module is disconnected, it may be impossible to detect an abnormality. Further, although it is considered that the possibility of occurrence is extremely low, there is a problem that the above control may not be possible even if the microcomputer constituting the throttle control module breaks down.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above, and is intended to be used when a signal line of a sensor is broken or when a microcomputer constituting a throttle control module breaks down. However, an object of the present invention is to provide an electronic throttle control device capable of performing fail-safe control reliably.

[0005]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as described in the claims. That is, in the invention described in claim 1, the throttle actuator and the throttle
A control module, an engine control module having an abnormality detection function of a throttle control and a function of shutting off power supply to an electromagnetic clutch and the like in addition to the original engine control function, and an electromagnetic clutch and a motor of a throttle actuator Are connected so that only one of the throttle control module and the engine control module can shut off the power supply to both of them. According to a second aspect of the present invention, in the electronic throttle control device according to the first aspect, at least a part of a requirement for judging abnormality detection of throttle control in the throttle control module and the engine control module. In addition, each is configured to include its own judgment requirements.

[0006]

According to the first aspect of the present invention, an abnormal condition of the throttle control is detected by the engine control module which originally controls the engine operation according to the same vehicle state signal as the throttle control module, and the abnormal condition is detected. In some cases, a means is provided for interrupting the power supply to the electromagnetic clutch and the motor of the throttle actuator so that the power supply to both the electromagnetic clutch and the motor can be interrupted by only one of the throttle control module and the engine control module. Connected to. Therefore, fail-safe control is reliably performed even when a signal line input to one of the throttle control module and the engine control module is broken or a microcomputer constituting one of the modules breaks down. I can do it. Since microcomputer failures are extremely rare, it is unlikely that microcomputers of two modules will fail simultaneously. Further, in the invention described in claim 2, the throttle control module and the engine control module are configured to detect the abnormality of the throttle control based on their own judgment requirements, so that only the same sensor output is provided. The abnormality determination can be performed more accurately than when the abnormality detection is performed based on the same determination requirements based on the determination. For example, when an abnormality is detected based on only the same sensor output based on the same determination requirement, the accelerator sensor 3 and the throttle sensor 4
If both fail and a special abnormality occurs in which both values are fixed at the value at the time of idling, there is a fear that the abnormality cannot be detected and the fail-safe function cannot be operated. is there. However, when both modules make an abnormality judgment based on their own judgment requirements, even if the above-mentioned special abnormality occurs, the abnormality can be reliably detected and the fail-safe function can be activated. In addition, since the engine control module originally used for engine control is configured to be used also for abnormality detection of throttle control, it can be configured at a lower cost than providing a dedicated abnormality determination module in duplicate, The engine parameters originally input to the engine control module can be effectively used for detecting an abnormality in the throttle control, and the accuracy of the abnormality determination can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a sectional view of a throttle actuator. First, in FIG. 1, reference numeral 1 denotes a throttle valve for adjusting an intake air amount of an engine, and reference numeral 2 denotes a DC motor. Reference numeral 3-1 denotes a first accelerator sensor for detecting a rotation angle of an accelerator drum, and reference numeral 3-2 denotes a depression angle of an accelerator pedal (accelerator opening).
Is a second accelerator sensor that detects a step angle based on an output voltage of a potentiometer. In the case where there is no particular need to distinguish between them, the above 3-1 and 3-2 are collectively referred to as an accelerator sensor 3. Reference numeral 4 denotes a throttle sensor, which detects a throttle opening by an output voltage of a potentiometer. An accelerator limit sensor 5 is turned off when the accelerator pedal is not operated. In FIG. 1, the first accelerator sensor 3-1, the second accelerator sensor 3-2, the throttle sensor 4, and the accelerator limit sensor 5 are located apart from the structural installation location and the wiring position. , Are duplicated in both positions. Reference numeral 6 denotes a throttle control module (T) for driving and controlling a throttle actuator.
CM), and is composed of the following blocks 7, 8, and 9. That is, reference numeral 7 denotes a one-chip microcomputer which has a built-in CPU, RAM, ROM, digital port, A / D port, and various timers. Reference numeral 8 denotes a motor drive bridge circuit that drives the DC motor 2 and shuts off the motor power supply according to a control signal of the microcomputer 7. Reference numeral 9 denotes a circuit for driving an electromagnetic clutch.
The first and second electromagnetic clutch power sources, which will be described later, can be shut off by the control signal of (1). Also,
10 is an engine control module (ECM)
And is composed of the following blocks 11, 12, and 13. That is, reference numeral 11 denotes a one-chip microcomputer having a built-in CPU, RAM, ROM, digital port, A / D port, and various timers. Reference numeral 12 denotes a motor drive power supply cutoff circuit, and reference numeral 13 denotes an electromagnetic clutch drive power supply cutoff circuit. It should be noted that the engine control module 10 is a module that originally controls the engine, and has various input signals and output signals therefor, but the display is omitted for parts unrelated to the present invention. The signals of the accelerator sensor 3 and the throttle sensor 4 are input to the throttle control module 6 and the engine control module 10. The power supply for the motor, the power supply cutoff circuit 13 for the motor drive, the accelerator limit sensor 5, the bridge circuit 8 for the motor drive, and the DC motor 2 are connected in series. The circuit 13, the electromagnetic clutch driving circuit 9, the first
The electromagnetic clutch and the second electromagnetic clutch are connected in series.

Next, the apparatus shown in FIG. 2 will be described. 2 is an electronic type in which a normally closed first electromagnetic clutch is disposed between an accelerator pedal and a throttle valve 1 and a normally open second electromagnetic clutch is disposed between a throttle valve 1 and a motor 2. It is a throttle actuator. 2, the throttle valve return spring 21 for urging the throttle valve 1 in the closing direction and the accelerator drum return spring 23 for urging the accelerator drum 22 connected to the accelerator pedal 1 with a wire in the closing direction are provided. Have been placed. An accelerator sensor 3 for measuring a rotation angle of the accelerator drum 22;
A throttle sensor 4 for measuring the rotation angle of the throttle shaft is arranged at a predetermined position. Further, in the electromagnetic clutch, a black portion is a throttle-side clutch plate, which is movable in the throttle axial direction by turning on / off the energization. In the first electromagnetic clutch, this clutch plate is always urged by a spring in the direction of connection with the accelerator drum 22, and in the second electromagnetic clutch, this clutch plate is always urged by the spring in the direction of non-connection with the motor 2. It is being rushed. In this embodiment, a DC motor is used as the motor 2.

Next, the operation of the apparatus shown in FIGS. 1 and 2 will be described. First, when the signals of the accelerator sensor 3 and the throttle sensor 4 input to the microcomputer 7 in the throttle control module 6 and the microcomputer 11 in the engine control module 10 are normal, the engine control module 10 Neither the power supply for the electromagnetic clutch nor the power supply for the motor is shut off on either the side or the throttle control module 6 side. Therefore, in this case, the first electromagnetic clutch is disconnected, the second electromagnetic clutch is connected, and the motor 2 is driven, so that the throttle valve 1 is electronically controlled to open and close. On the other hand, when the input signals of the accelerator sensor 3 and the throttle sensor 4 are abnormal (details will be described later), both the engine control module 10 side and the throttle control module 6 side
The power supply for the electromagnetic clutch and the power supply for the motor are cut off. As described above, the engine control module 10 and the throttle control module 6 are connected in series between the electromagnetic clutch power supply and the electromagnetic clutch and the motor power supply and the motor, respectively.
If at least one of the two modules is shut off, the two power supplies are surely shut off. Therefore, the power supply to the electromagnetic clutch and the power supply to the motor by one of the microcomputers is interrupted due to the disconnection of the signal line from the sensor input to the microcomputers in both modules or the failure of the microcomputers in both modules. Even in the case where it is not possible, the power supply can be reliably shut off by the microcomputer which operates normally. Therefore, when an abnormality occurs, the fail-safe function of stopping the electronic control of the throttle valve and switching to the mechanical opening / closing control from the accelerator pedal can be more reliably operated.

FIG. 3 is a flowchart showing the processing in the above embodiment. This flowchart shows only the part of the abnormality determination and the fail-safe processing at the time of abnormality.

In FIG. 3, steps P1 to P5 are flow charts on the engine control module side,
Steps Q1 to Q5 are flowcharts on the throttle control module side. First, at P1, the accelerator opening Acc is read from the signal of the accelerator sensor 3. At P2, the actual throttle opening Tvo corresponding to the actual throttle valve opening from the signal of the throttle sensor 4
Read. At P3, a value of the throttle opening Tv1 corresponding to the value of the accelerator opening Acc is calculated based on a data map stored in advance. Here, the relationship between the accelerator opening Acc and the throttle opening Tv1 is stored as a characteristic as shown in FIG. 5, for example. This property is
This is set in advance in consideration of the drive system characteristics and the drivability of the vehicle. At P4, the throttle opening Tv1 calculated at P3 is compared with the actual throttle opening Tvo, and if they match, the routine goes to return.
Proceed to P5. At P5, the electromagnetic clutch drive power supply shutoff circuit 12 and the motor drive power supply shutoff circuit 13 are operated to shut off the electromagnetic clutch power supply and the motor power supply, thereby stopping the electronic control of the throttle. Also in the flowcharts Q1 to Q5 on the throttle control module side, the same processing as P1 to P5 is performed to determine normal / abnormal and control.
As described above, in the flowchart of FIG. 3, when the value of the throttle opening Tv1 obtained from the accelerator opening Acc of the accelerator sensor 3 does not match the value of the actual throttle opening Tvo actually measured by the throttle sensor 4, Is determined to be abnormal.

Next, a second embodiment of the present invention will be described. In FIG. 1, the microcomputer 11 in the engine control module 10 originally controls the engine. Therefore, various microcomputers controlling the engine other than the signals from the accelerator sensor 3 and the throttle sensor 4 are used. Handles signals and parameters.
Therefore, it is possible to determine the abnormality of the throttle actuator from these parameters and the like. For example, the engine output torque is estimated from the intake air amount and the engine speed or the fuel injection amount and the engine speed input to the engine control module 10, and the information from the accelerator sensor 3 and the throttle sensor 4 and the engine speed are estimated. And the required output torque of the driver obtained from
If the comparison value deviates by a predetermined value or more, it may be determined that the throttle actuator is abnormal. On the throttle control module 6 side, the throttle control module 6
A self-diagnosis function can be provided within the system. For example, when the value of the accelerator sensor 3 (for example, the average value of the values indicated by the first accelerator sensor 3-1 and the second accelerator sensor 3-2) indicates an idling state, the accelerator limit sensor 5 (normally turned off when idling) Switch) indicates an ON value, that is, a value that is not idling, it can be determined that the accelerator limit sensor 5 has failed. As mentioned above, the throttle control
Module 6 and engine control module 1
If 0, the throttle / actuator abnormality is detected based on the unique determination requirement, and if it is determined that each is abnormal, the power supply for the electromagnetic clutch and the power supply for the motor can be independently shut off. . In this case, as described above, the engine control module 10 and the throttle control module 6 are connected in series between the electromagnetic clutch power supply and the electromagnetic clutch and the motor power supply and the motor, respectively.
If at least one of the two modules is shut off, the two power supplies are surely shut off. Therefore, the power supply to the electromagnetic clutch and the power supply to the motor by one of the microcomputers is interrupted due to the disconnection of the signal line from the sensor input to the microcomputers in both modules or the failure of the microcomputers in both modules. Even in the case where it is not possible, the power supply can be reliably shut off by the microcomputer which operates normally. Therefore, when an abnormality occurs, the fail-safe function of stopping the electronic control of the throttle valve and switching to the mechanical opening / closing control from the accelerator pedal can be more reliably operated. For example, in the first embodiment shown in the flowchart of FIG. 3, when the accelerator sensor 3 and the throttle sensor 4 both fail and a special abnormality occurs in which both values are fixed at the idling value. Include steps P4 and Q in FIG.
4 are both determined to be normal, and the fail-safe function cannot be operated. In this regard, in the second embodiment, as shown in the flowchart of FIG.
Since both modules make an abnormality judgment based on their own judgment requirements, even if the above special abnormality occurs,
An abnormality can be reliably detected and the fail-safe function can be activated. As described above, in the case where the throttle control module 6 and the engine control module 10 detect an abnormality of the throttle actuator based on their own judgment requirements, all judgment requirements are different between the two modules. It may be something,
Only some of the judgment requirements may be different. For example, as described in the first embodiment, both modules may include a portion that performs abnormality detection based on the same determination requirement, and may further include portions having different determination requirements.

FIG. 4 is a flowchart showing the processing in the second embodiment of the present invention as described above. In FIG. 4, steps P1 to P8 correspond to engine control
Flowchart of module 10 side, steps Q1 to Q
7 is a flowchart on the throttle control module 6 side. In the flowchart of FIG. 4, P1 to P5 and Q1 to Q5 are the same as the steps in FIG. First, at P1, the accelerator opening Acc is read from the signal of the accelerator sensor 3. P
In step 2, the actual throttle opening Tvo corresponding to the actual throttle valve opening is read from the signal of the throttle sensor 4. At P3, a value of the throttle opening Tv1 corresponding to the value of the accelerator opening Acc is calculated based on a data map stored in advance. Here, accelerator opening A
The relationship between cc and the throttle opening Tv1 is stored as a characteristic as shown in FIG. 5, for example. This characteristic is set in advance in consideration of the drive system characteristic and the drivability of the vehicle. In P4, the throttle opening Tv calculated in P3
1 is compared with the actual throttle opening Tvo. If they do not match, the process proceeds to P5, and if they match, the process proceeds to P6.
On the other hand, at P6, the intake air amount and the engine speed input to the engine control module 10 and calculated,
Alternatively, the actual output torque TRQ0 of the engine is estimated from the fuel injection amount and the engine speed based on a data map stored in advance. Here, the actual engine output torque TR corresponding to the fuel injection amount and the engine speed is
The characteristics of Q0 are stored, for example, as characteristics shown in FIG. The characteristics of the actual engine output torque TRQ0 corresponding to the intake air amount and the engine speed are also the same as those in FIG. Next, at P7, the required output torque TRQ1 of the driver is estimated from the accelerator opening and the engine speed input to the engine control module 10 based on a data map stored in advance. Here, the characteristics of the driver's required output torque TRQ1 corresponding to the accelerator opening and the engine speed are stored, for example, as characteristics shown in FIG. At P8, the engine output torque TRQ0 calculated at P6 and P7 and the required output torque TRQ
If the error is larger than the predetermined value TRQf, the process proceeds to P5. At P5, the electromagnetic clutch drive power supply shutoff circuit 12 and the motor drive power supply shutoff circuit 13 are operated to shut off the electromagnetic clutch power supply and the motor power supply, thereby stopping the electronic control of the throttle. Next, in the flowchart on the throttle control module side, steps Q1 to Q5
Same as 1 to P5. Next, in Q6,
A self-diagnosis in the control module 6 is performed.
For example, when the value of the accelerator sensor 3 (for example, the average value of the values indicated by the first accelerator sensor 3-1 and the second accelerator sensor 3-2) indicates an idling state, the accelerator limit sensor 5 (normally turned off when idling) Switch) indicates an ON value, that is, a value that is not idling, it is determined that the accelerator limit sensor 5 has failed. In Q7, when it is determined in Q6 that there is a failure, the process proceeds to Q5. In Q5, the power supply for the electromagnetic clutch and the power supply for the motor are shut off by the motor drive bridge circuit 8 and the electromagnetic clutch drive circuit 9, and the electronic control of the throttle is stopped.

[0014]

As described above, according to the first aspect of the present invention, the engine control module that originally controls the operation of the engine is provided with the same abnormality determination function as the throttle control module, and The configuration is such that the power supply to both the electromagnetic clutch and the motor can be interrupted by only one of the throttle control module and the engine control module. Fail-safe control can be reliably performed even when a disconnection occurs or when a microcomputer constituting one of the modules fails. Also,
According to the second aspect of the present invention, the throttle control module and the engine control module are configured to detect the abnormality of the throttle control by their own judgment requirements, so that only the same sensor output is used. Abnormality determination can be performed more accurately than when abnormality detection is performed with the same determination requirements. Also, by using the engine control module that is originally used for engine control for detecting abnormality in throttle control, it is possible to configure the system more cheaply than providing a dedicated abnormality determination module in duplicate, and to use the engine control module. Thus, it is possible to effectively utilize the engine parameters originally input to the ECU to detect an abnormality in the throttle control, thereby improving the accuracy of the abnormality determination.

[Brief description of the drawings]

FIG. 1 is an embodiment diagram showing the overall configuration of the present invention.

FIG. 2 is a cross-sectional view of one embodiment of a throttle actuator.

FIG. 3 is a flowchart showing a calculation process according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a calculation process according to a second embodiment of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between a throttle opening and an accelerator opening.

FIG. 6 is a characteristic diagram showing characteristics of an engine output torque corresponding to a fuel injection amount and an engine speed.

FIG. 7 is a characteristic diagram showing characteristics of a required output torque corresponding to an accelerator opening and an engine speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Throttle valve 2 ... DC motor 3-1 ... 1st accelerator sensor 3-2 ... 2nd accelerator sensor 4 ... Throttle sensor 5 ... Accelerator limit sensor 6 ... Throttle control module (TCM) 7 ... Microcomputer 8 ... Motor Drive bridge circuit 9 ... Electromagnetic clutch drive circuit 10 ... Engine control module (ECM) 11 ... Microcomputer 12 ... Motor drive power cutoff circuit 13 ... Electromagnetic clutch drive power cutoff circuit 21 ... Throttle valve return spring 22 … Accelerator drum 23… return spring for accelerator drum

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 9/02 F02D 11/02 F02D 41/22 F02D 45/00

Claims (2)

(57) [Claims] A first electromagnetic clutch of a normally closed type which is in a connected state when not energized, and a second electromagnetic clutch of a normally open type which is in a non-connected state when not energized; One end of the first electromagnetic clutch and one end of the second electromagnetic clutch are connected, a motor is connected to the other end of the second electromagnetic clutch, and accelerator operating means is connected to the other end of the first electromagnetic clutch. And
Normally, the first electromagnetic clutch is disconnected and the second electromagnetic clutch is connected to control the opening and closing of the throttle valve by the motor. A throttle valve configured to de-energize the electromagnetic clutch to connect the first electromagnetic clutch and to disconnect the second electromagnetic clutch to control opening and closing of the throttle valve by the accelerator operating means. An actuator, controlling the throttle actuator in accordance with a vehicle state signal including at least an operation amount signal of the accelerator operation means, and detecting an abnormal state of the throttle control; A throttle control module with means for blocking An engine that controls engine operation and detects an abnormal state of throttle control in response to the same vehicle state signal as the throttle control module, and shuts off the power to both the electromagnetic clutches and the motor when abnormal. A control module, and the power supply to both the electromagnetic clutch and the motor is connected so that only one of the throttle control module and the engine control module can be disconnected. Electronic throttle control device. 2. The electronic throttle control device according to claim 1, wherein at least a part of a condition for judging abnormality detection of throttle control in the throttle control module and the engine control module includes a unique condition. An electronic throttle control device comprising a judgment requirement.