JP2891019B2 - Vehicle driving force 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 for electrically controlling a throttle valve and a driving force control device for a vehicle equipped with an automatic transmission. The present invention relates to a driving force control device for a vehicle when a failure occurs.

[0002]

2. Description of the Related Art Conventionally, there is an electronic throttle control device for electrically controlling a throttle valve by a motor or the like.
In Japanese Patent Application Laid-Open No. 2-149734, when a failure occurs such that the electronic throttle control device cannot be opened, the failure is detected and an auxiliary air passage provided in an auxiliary air passage bypassing the throttle valve is detected. The air control valve (AAC valve) is opened.

In this conventional example, even when the electronic throttle control device fails to open, the auxiliary air control valve is opened to secure a certain level of driving force and enable self-sustaining traveling. As a result, it is possible to travel to the service station by itself for repair of a failure, and to evacuate from an intersection, an expressway, or the like by itself. Such a function that can ensure a certain level of running performance even at the time of failure is called a limp home function.

[0004]

However, when this conventional example is applied to a vehicle with an automatic transmission, there is a problem that a sufficient driving force is not always obtained, and it becomes difficult to travel independently. . This is for the following reason. In a normal automatic transmission, selection control of a transmission gear position is performed using the vehicle speed and the throttle opening as parameters, so that a driving force corresponding to the throttle opening is obtained. However, when the electronic throttle drive device fails to perform the opening operation, the throttle opening is always zero, completely different from the operation amount of the accelerator pedal (accelerator opening) which is the driver's intention to accelerate. Therefore, if the same shift control as in the normal state is performed, an optimum driving force cannot be obtained. Furthermore, since the engine output torque obtained only by the amount of auxiliary air that bypasses the throttle valve by opening the auxiliary air control valve is considerably limited, independent traveling is impossible unless the transmission is optimally controlled.

In the prior art, when the electronic throttle control device fails to open, the auxiliary air control valve is only opened, so that the vehicle speed is controlled only by the brake operation, which is inconvenient. There was a problem that it is. In view of such a conventional problem, the present invention can provide a sufficient driving force for enabling self-sustained traveling when an electronic throttle control device fails to open and can control vehicle speed. It is an object of the present invention to be able to more reliably perform the above.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a vehicle equipped with an electronic throttle control device for electrically controlling a throttle valve and an automatic transmission, as shown in FIG. The inoperable failure detecting means A for detecting that the control device has failed to perform the inoperable failure. When the inoperable failure of the electronic throttle control device is detected by the detecting means, the driver's intention to accelerate is determined. Means for discriminating driver's acceleration intention B, means for determining highest gear position for shifting gear based on the determined driver's intention to accelerate gear, and means C for determining highest gear position for shifting gear; A transmission gear position selecting means D for selecting a transmission gear position at which the maximum driving force is obtained from among the transmission gear positions below the transmission gear position, and an automatic transmission based on the selected transmission gear position. It provided the automatic transmission control unit E for controlling the transmission gear position of, constituting the vehicle driving force control apparatus.

Here, it is desirable that the driver acceleration intention determining means B is means for detecting the operation amount of the accelerator pedal (accelerator opening) by the driver.

[0008]

In the above configuration, when the electronic throttle control device has a failure in which the opening operation cannot be performed, when the failure is detected, first, the driver's intention to accelerate is determined. Determine the step position. And
A transmission gear position at which the maximum driving force is obtained is selected from among the transmission gear positions below the determined allowable transmission gear highest gear position. Then, the automatic transmission is controlled based on the selected shift gear position.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In this embodiment, a four-speed automatic transmission is connected to a four-cylinder engine with an electronic throttle control device. The driving force is controlled by a throttle controller, an engine controller, and an automatic transmission (A / T) controller. I have.

FIG. 2 is a system diagram of the present embodiment. A throttle valve 1 is provided in an intake passage of the engine, and the throttle valve 1 is controlled to be opened and closed by an electronic throttle control device. FIG. 3 shows details of the actuator structure of the electronic throttle control device.

In FIG. 3, a throttle valve 1 is provided with a throttle valve return spring 3 for urging the throttle valve 1 in a closing direction on a valve shaft 2 thereof.
At one end of a valve shaft 2 of the throttle valve 1, an accelerator drum 6 connected to an accelerator pedal 4 (see FIG. 2) via a wire 5 is rotatably supported. An accelerator drum return spring 7 for urging the accelerator drum 6 in the closing direction is acted on the accelerator drum 6.

The accelerator drum 6 and the valve shaft 2
And a first electromagnetic clutch 8 is interposed therebetween. First
The electromagnetic clutch 8 includes a clutch plate 8a attached to the accelerator drum 6, and a clutch plate 8b which rotates integrally with the valve shaft 2 and is slidable in the axial direction. In the first electromagnetic clutch 8, the clutch plate 8b is always urged by the spring 8c in the connection direction with the clutch plate 8a, and is in a connected state when the coil 8d is not energized, and is opened when the coil 8d is energized (normally closed). ).

A motor drum 11 driven by a DC motor 9 via a reduction gear 10 is rotatably supported on the other end of the valve shaft 2 of the throttle valve 1. A second electromagnetic clutch 12 is interposed between the motor drum 11 and the valve shaft 2. Second electromagnetic clutch 12
Has a clutch plate 12a attached to the motor drum 11, and a clutch plate 12b that rotates integrally with the valve shaft 2 and is slidable in the axial direction. In the second electromagnetic clutch 12,
The clutch plate 12b is always urged by a spring 12c in the direction of opening with the clutch plate 12a, and is in an open state when the coil 12d is not energized and in a connected state when energized (normally open).

Here, the first and second electromagnetic clutches 8 and 12 and the DC motor 9 are controlled by a throttle controller 13 (see FIG. 2) described later. The system diagram of FIG. 2 will be further described. An auxiliary air passage 14 is formed in the intake passage of the engine bypassing the throttle valve 1, and an electromagnetic auxiliary air control valve 15 is interposed in the auxiliary air passage 14.

An electromagnetic fuel injection valve 16 is provided for each cylinder downstream of a branch portion of the intake passage of the engine to each cylinder. Here, the fuel injection valve 16 and the auxiliary air control valve 15
Is controlled by an engine controller 17 described later.
Although the illustration of the automatic transmission (A / T) is omitted, it is controlled by an A / T controller 18 described later.

The throttle controller 13 is constituted by using a chip microcomputer, which includes a CPU, a ROM, a RAM, a digital port, an A / D
Built-in port and various timers. Explaining the control contents, when the system is normal, an instruction to energize the first and second electromagnetic clutches 8 and 12 is made, only the second electromagnetic clutch 12 is connected, and the throttle valve 1 is driven by the DC motor 9. To do it. Then, the target throttle opening is calculated based on various sensor signals, and the drive voltage to the DC motor 9 is controlled so that the actual throttle opening matches the target throttle opening.

The engine controller 17 is also configured using a one-chip microcomputer, and calculates the fuel injection amount corresponding to the intake air amount based on various sensor signals.
A fuel injection pulse signal is output to the fuel injection valve 16 of each cylinder in synchronization with the engine rotation to perform fuel injection control. Also,
The number of fuel injection cylinders is controlled based on the maximum allowable driving force obtained from the accelerator opening and the vehicle speed. Further, under the idling operation condition, the auxiliary air control valve 15 is duty-controlled to control the auxiliary air amount so as to control the idle speed to the target idle speed. In addition, according to the flowchart of FIG. 7 described later, an opening failure of the electronic throttle control device is detected, and in that case, the auxiliary air amount control at the time of the opening failure is performed.

The A / T controller 18 is also formed using a one-chip microcomputer, and normally performs a shift control corresponding to the vehicle speed and the throttle opening based on various sensor signals. In addition, according to a flowchart of FIG. 4 described later, an opening failure of the electronic throttle control device is detected, and in that case, a shift control at the time of the opening failure is performed.

For these controls, various sensors are provided, and sensor signals are input to appropriate controllers 13, 17, and 18. Reference numerals 19 and 20 denote accelerator sensors (double system), which detect the accelerator opening ACC based on the output voltage of the potentiometer. Reference numeral 21 denotes a throttle sensor, which detects a throttle opening TVO based on an output voltage of a potentiometer. Reference numeral 22 denotes a vehicle speed sensor, which detects the vehicle speed V by an electromagnetic pickup or the like provided on the transmission output shaft.
A pulse signal having a frequency proportional to SP is output. Reference numeral 23 denotes a pressure sensor which outputs a voltage corresponding to the intake negative pressure Pa, and is used for measuring an intake air amount. Reference numeral 24 denotes a crank angle sensor which outputs a reference crank angle signal and a unit crank angle signal in synchronization with the rotation of the crankshaft, and is used for detecting the crank angle and calculating the engine speed Ne.

FIG. 4 shows a part of a control operation performed by the microcomputer in the A / T controller 18 (a shift control routine for a failure in which a throttle opening operation cannot be performed) for a predetermined time (for example, 10 ms).
c) is executed every time. In step 1 (denoted as S1 in the figure, the same applies hereinafter), the accelerator opening ACC is detected based on signals from the accelerator sensors 19 and 20.

In step 2, the throttle opening TVO is detected based on the signal from the throttle sensor 21.
In step 3, the electronic throttle control device is diagnosed based on the detected accelerator opening ACC and throttle opening TVO, and it is determined whether or not there is a failure to disable the opening operation. Specifically, when "the state of TVO = 0 (deg) and ACC> 5 (deg) continues for 500 msec or more", it is determined that the electronic throttle control device does not allow the opening operation and the failure is determined. After that, "TVO> 5 (deg) and | TVO-ACC | <
2 (deg) status continues for 500 msec or more ”
Do not return judgment.

In step 4, based on the diagnosis result in step 3, if there is no failure, this routine is terminated, and if there is a failure, steps 5 to 8 are executed. In step 5,
Based on the accelerator opening ACC detected in step 1 as the driver's intention to accelerate, the allowable maximum gear position (minimum gear ratio) is determined. This is for limiting the reaching vehicle speed, and the use of up to a higher transmission gear position where the reaching vehicle speed is higher is permitted as the accelerator opening is larger (the driver's intention to accelerate is larger). Specifically, as shown in FIG. 5, the maximum allowable gear position (nth speed) is determined according to the accelerator opening ACC.

In step 6, the throttle valve is fully closed, which is obtained when the transmission gear positions are equal to or lower than the maximum allowable gear position (first to n-th gears if the maximum allowable gear position is n-speed). (TVO = 0) and the driving force of the vehicle when the auxiliary air control valve is fully opened is obtained. For example, based on a vehicle driving force characteristic map when the throttle valve is fully closed and the auxiliary air control valve is fully opened in consideration of engine characteristics, automatic transmission characteristics, and the like, as shown in FIG. Sensor
Estimated driving forces F (1) to F (n) are determined for each shift gear position from the current vehicle speed VSP detected by 22.

In step 7, the estimated driving forces F (1) to F (n) at each shift gear position below the maximum allowable gear position obtained in step 6 are compared with each other to obtain the largest drive force. The gear position to be changed. Step 8
Then, the automatic transmission hydraulic valve control output port is rewritten in accordance with the transmission gear position determined in step 7, and this routine ends.

Here, the portion from step 1 to step 4 corresponds to the opening operation impossible failure detecting means. Step 1
Corresponds to the driver's acceleration intention determination means.
Corresponds to the permissible transmission gear position determining means, the steps 6 and 7 correspond to the transmission gear position selecting means for achieving the maximum driving force, and the step 8 corresponds to the transmission control means.

FIG. 7 shows a part of a control operation performed by the microcomputer in the engine controller 17 (an auxiliary air control valve control routine for a failure in which a throttle opening operation cannot be performed), which is executed at regular intervals (for example, every 10 msec). Steps 11 to 14 are the same as steps 1 to 4 in FIG.
Whether the electronic throttle control device has an open operation failure is diagnosed based on the accelerator opening and the throttle opening, and the process proceeds to step 15 only when it is determined that there is an open operation failure.

At step 15, the auxiliary air control valve 15 is forcibly fully opened in order to cope with the failure of the electronic throttle controller to make the opening operation impossible, and this routine is terminated. Next, the operation will be described. If the electronic throttle control device fails to open, the throttle valve 1 remains fully closed no matter how much the driver steps on the accelerator pedal 4. In this case, the output of the engine in the idle state is not sufficient for self-sustained traveling. Therefore, the engine output is obtained to some extent by fully opening the auxiliary air control valve 15 (see FIG. 6A).

On the other hand, as shown in FIG. 6 (b), the order of magnitude of the vehicle driving force F obtained at each shift gear position differs depending on the vehicle speed VSP. In other words, 1 near vehicle speed zero
When the vehicle speed is increased, the driving force becomes the largest. However, as the vehicle speed increases, the transmission gear position at which the maximum driving force can be obtained changes to the second, third, and fourth speeds. Therefore, in the present embodiment, the gear position at which the maximum driving force is obtained is selected according to the vehicle speed. In other words, the vehicle accelerates along the upper limit value of the driving force line corresponding to each shift speed in FIG. 6B, and if the upshift is allowed up to the fourth speed, the running resistance and the driving resistance at the point D are reduced. driving force and is in agreement reaches a certain vehicle speed V _4.

Further, in this embodiment, the accelerator opening AC
Since the maximum allowable gear position is selected in accordance with C, it is possible to select the reached vehicle speed by the accelerator opening. For example, if the accelerator opening is 0 (deg), 1
Since Hayashi either not permitted, will coincide with the running resistance at point A, it reaches the vehicle speed becomes V _1. Accelerator opening is 50 (deg)
In the case of, upshifts up to 3rd gear are allowed,
Consistent with the running resistance at the point C, it reaches the vehicle speed becomes V _3.

As described above, even when the engine output state is low when the throttle is fully closed, the vehicle can be smoothly accelerated in order to obtain the maximum driving force, so that the vehicle can be accelerated smoothly. Can be operated step by step. In this embodiment, A / T
The controller 18 and the engine controller 17 detect the failure to open the electronic throttle control device, but the throttle 13 detects the failure to operate the opening by self-diagnosis, and the A / T controller 18 and the engine controller A configuration may be made in which the failure control 17 is required.

When the electronic throttle control device fails to open, the auxiliary air control valve 15 does not always need to be fully opened, and reaches the vehicle speed required for self-sustained traveling at least in four speeds at the time of failure. What is necessary is just to fix to the opening which can obtain the possible level of engine output.

[0032]

As described above, according to the present invention, when it is detected that the electronic throttle control device has failed to perform the opening operation, the maximum allowable transmission gear determined according to the driver's intention to accelerate is determined. From among the gear positions below the gear position,
The automatic transmission is controlled by selecting the transmission gear position where the maximum driving force can be obtained, so even if the electronic throttle control device fails to open, it accelerates as smoothly as possible, Vehicle speed.

Further, if the accelerator opening is detected as the driver's intention to accelerate and the maximum gear position of the permissible transmission gear is determined accordingly, it is possible to operate the reaching vehicle speed stepwise by operating the accelerator. Therefore, even at the time of failure, the vehicle speed can be controlled by the accelerator operation and the brake operation, and the vehicle can run more safely.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram showing one embodiment of the present invention.

FIG. 3 is a diagram showing an actuator structure of an electronic control throttle device.

FIG. 4 is a flowchart showing a shift control routine for a failure in which a throttle opening operation cannot be performed;

FIG. 5 is a diagram showing an accelerator opening-allowable transmission gear highest gear position correspondence map;

FIG. 6 is a diagram showing a map of engine output torque and vehicle driving force characteristics when the throttle valve is fully closed and the auxiliary air control valve is fully opened.

FIG. 7 is a flowchart showing an auxiliary air control valve control routine for a failure in which a throttle opening operation cannot be performed;

[Explanation of symbols]

 Reference Signs List 1 throttle valve 4 accelerator pedal 8 first electromagnetic clutch 9 DC motor 12 second electromagnetic clutch 13 throttle controller 14 auxiliary air passage 15 auxiliary air control valve 16 fuel injection valve 17 engine controller 18 A / T controller 19, 20 accelerator sensor 21 Throttle sensor 22 Vehicle speed sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-272634 (JP, A) JP-A-3-89070 (JP, A) JP-A-2-3544 (JP, A) JP-A-63-1988 103742 (JP, A) JP-A-1-120464 (JP, A) JP-A-63-246425 (JP, A) JP-A-1-116359 (JP, A) JP-A-2-195070 (JP, A) JP-A-5-272635 (JP, A) JP-A-5-301535 (JP, A) (58) Fields studied (Int. Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16 -61/24 F16H 63/40-63/48 B60K 41/00-41/28 F02D 29/00-29/06 F02D 41/00-41/40 F02D 45/00

Claims (2)

(57) [Claims] An inoperable failure in a vehicle including an electronic throttle control device for electrically controlling a throttle valve and an automatic transmission detects that the electronic throttle control device has failed to open. Detecting means, driver acceleration intention determining means for determining the driver's intention to accelerate when the electronic throttle control device detects that the electronic throttle control device cannot be opened, and based on the determined driver acceleration intention. Transmission gear highest gear position determining means for determining the maximum allowable transmission gear position and a transmission gear position at which the maximum driving force is obtained from among the transmission gear positions equal to or less than the determined allowable transmission gear maximum gear position. It is characterized in that a transmission gear position selecting means for achieving the maximum driving force and automatic transmission control means for controlling the transmission gear position of the automatic transmission based on the selected transmission gear position are provided. Driving force control device for vehicle. 2. The vehicle driving force control device according to claim 1, wherein the driver acceleration intention determination means is means for detecting an operation amount of an accelerator pedal by the driver.