JPH1148831A - Output control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform safe control on the transmission side, by sending torque signals of an engine power to a control device of a transmission, diagnosing existence of abnormality of a control device of an engine, and sending a signal which indicates unsteady state of engine power torque signals to the control device of the transmission if the abnormality exists. SOLUTION: A control unit inputs various sensor signals to control throttle opening and fuel injection amount, and sends signals to a transmission control device side for gear shift, control and line pressure control as cooperative control between an engine and a transmission. Vehicle speed, acceleration opening, engine power torque signals, or others are input into a control unit 33 for controlling the transmission and a gear shift control valve 32 and a line pressure control valve 31 are adjusted to control a gear ratio and line pressure. When torque control is abnormal, a torque maximum value side fixing value predetermined as torque unsteady state or net throttle opening is sent. On the transmission side, engine power torque is considered larger, the line pressure can be controlled large, and belt slip due to insufficient line pressure is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control device for a vehicle for performing cooperative control of an internal combustion engine and a transmission.

[0002]

2. Description of the Related Art Conventionally, in this type of vehicle output control device,
From the control device of the engine, to the control device of the transmission, transmit a throttle opening signal or a torque signal calculated from the intake air flow rate and the engine speed, and on the control device side of the transmission,
Based on this, the line pressure is controlled so that a line pressure corresponding to the engine output torque is obtained (see Japanese Patent Application Laid-Open No. Hei 8-
278212).

[0003]

However, for example, due to abnormality in so-called torque demand control using an electronically controlled throttle valve, the torque between the torque actually output from the engine and the torque transmitted to the control device of the transmission is reduced. Causes a difference between the line pressure for the transmission control with respect to the assumed torque amount and the actually required line pressure in the transmission side control, so that the belt slip due to insufficient line pressure. Etc. occur and affect transmission control.

The present invention has been made in view of the above-mentioned conventional problems, and when transmitting an engine output torque signal from an engine control device to a transmission control device, the signal becomes unreliable. It is another object of the present invention to provide a vehicle output control device capable of performing fail-safe control so that control on the transmission side can be made safe.

[0005]

According to the present invention, as shown in FIG. 1A, an engine output torque signal generating means for generating an engine output torque signal is provided to an engine control device. An engine output torque signal transmitting means for transmitting an engine output torque signal to a transmission control device, while receiving a diagnosis result of a diagnosis means for diagnosing the presence or absence of an abnormality in the engine control device, And a diagnostic signal transmitting means for transmitting a signal indicating that the engine output torque signal is in an indeterminate state to a control device of the transmission.

[0006] In the invention according to claim 2, the engine output torque signal transmitting means receives a diagnosis result of a diagnosis means for diagnosing the presence or absence of an abnormality in the engine control device, and transmits the engine output torque to be transmitted when there is an abnormality. It is characterized by comprising torque signal replacement means for replacing the torque signal with a signal for fail-safe. The invention according to claim 3 is characterized in that the fail-safe signal corresponds to a predetermined fixed value on the torque maximum value side.

According to a fourth aspect of the present invention, the engine output torque signal generating means converts the accelerator opening detected by the accelerator opening detecting means into a driver request torque as shown in FIG. Request torque conversion means, engine request torque calculation means for calculating an engine request torque independent of the driver request, target torque calculation means for adding the driver request torque and the engine request torque to calculate a target torque, and a target torque And a throttle opening equivalent value conversion means for converting the target torque into a throttle opening equivalent value, and transmits a throttle opening equivalent value of a target torque as an engine output torque signal.

In the invention according to claim 5, the engine output torque signal generating means converts the accelerator opening detected by the accelerator opening detecting means into a driver request torque as shown in FIG. 1 (B). Request torque conversion means, engine request torque calculation means for calculating an engine request torque independent of the driver request, target torque calculation means for adding the driver request torque and the engine request torque to calculate a target torque, and a target torque And a throttle opening equivalent value converting means for converting the throttle opening equivalent value of the target torque as an engine output torque signal. , Corresponding to the actual throttle opening.

In the invention according to claim 6, the diagnosis means detects at least a deviation between the target throttle opening and the actual throttle opening of the electronically controlled throttle valve, and when the difference is equal to or higher than a predetermined level, diagnoses that there is an abnormality. It is characterized by that. The invention according to claim 7 is characterized in that the transmission control device includes a line pressure control unit that controls a line pressure of the transmission based on an engine output torque signal.

[0010]

According to the first aspect of the present invention, when the engine output torque signal is transmitted from the engine control device to the transmission control device, the diagnosis result is received by the diagnosis means, Since the signal indicating that the engine output torque signal is in an indefinite state is transmitted, the abnormal condition handling process can be performed on the side of the transmission control device.

According to the second aspect of the present invention, the engine output torque signal to be transmitted is replaced with a signal for fail-safe when there is an abnormality in response to the diagnosis result of the diagnosis means. The abnormality handling process can be performed only on the control device side of the engine without performing any special process on the side. According to the third aspect of the invention, the fail-safe signal corresponds to the fixed value on the torque maximum value side, so that the control amount shortage on the transmission side can be resolved.

According to the present invention, when the engine output torque signal is generated, the accelerator opening is converted into the driver request torque, and the engine request torque irrelevant to the driver request is calculated and added. By calculating the target torque, the engine output torque can be accurately grasped in an internal combustion engine in which the engine output torque is not uniquely determined with respect to the throttle opening, and the target torque is set to a value corresponding to the throttle opening. By converting and transmitting this as the engine output torque signal, there is an advantage that the conventional control based on the throttle opening on the transmission side can be used as it is.

According to the fifth aspect of the present invention, when generating the engine output torque signal, the accelerator opening is converted into the driver required torque, and the engine required torque irrelevant to the driver request is calculated and added. By calculating the target torque, the engine output torque can be accurately grasped in an internal combustion engine in which the engine output torque is not uniquely determined with respect to the throttle opening, and the target torque is set to a value corresponding to the throttle opening. By converting and transmitting this as the engine output torque signal, there is an advantage that the conventional control based on the throttle opening on the transmission side can be used as it is. Furthermore,
By setting the fail-safe signal to correspond to the actual throttle opening, the actual throttle opening is larger than the throttle opening equivalent value of the target torque, so that the control amount shortage on the transmission side can be resolved.

According to the present invention, the deviation between the target throttle opening and the actual throttle opening of the electronically controlled throttle valve is detected, and when the difference is equal to or higher than a predetermined level, it is diagnosed that there is an abnormality. Diagnosis is possible. Claim 7
According to the present invention, by applying the present invention to line pressure control of a transmission, belt slippage due to insufficient line pressure and further hardware failure due to this can be avoided.

[0015]

Embodiments of the present invention will be described below. FIG. 2 is a system diagram of a direct injection spark ignition type internal combustion engine showing an embodiment. First, this will be described.
Air is sucked into the combustion chamber of each cylinder of the internal combustion engine 1 mounted on the vehicle from the air cleaner 2 through the intake passage 3 under the control of the electronically controlled throttle valve 4.

The opening of the electronically controlled throttle valve 4 is controlled by a step motor or the like operated by a signal from the control unit 10. An electromagnetic fuel injection valve (injector) 5 is provided so as to directly inject fuel (gasoline) into the combustion chamber. The fuel injection valve 5 is energized by a solenoid in response to an injection pulse signal output in the intake stroke or the compression stroke from the control unit 10 in synchronization with the engine rotation, opens the valve, and injects fuel adjusted to a predetermined pressure. It has become. The injected fuel diffuses into the combustion chamber in the case of the intake stroke injection to form a homogeneous mixture, and in the case of the compression stroke injection, forms a stratified mixture around the ignition plug 6. On the basis of an ignition signal from the control unit 10, the fuel is ignited by the ignition plug 6 and burns (homogeneous combustion or stratified combustion). The combustion method is a combination of air-fuel ratio control and homogeneous stoichiometric combustion.
It is divided into homogeneous lean combustion and stratified lean combustion.

Exhaust gas from the engine 1 is discharged from an exhaust passage 7, and an exhaust purification catalyst 8 is interposed in the exhaust passage 7. The control unit 10 includes a CPU, a ROM, an R
A microcomputer including an AM, an A / D converter, an input / output interface, and the like is provided, and signals are input from various sensors.

The various sensors include a crank angle sensor 1 for detecting rotation of a crankshaft or a camshaft of the engine 1.
1 and 12 are provided. When the number of cylinders is n, these crank angle sensors 11 and 12 provide a crank angle 720
The reference pulse signal RE at a predetermined crank angle position (a predetermined crank angle position before the compression top dead center of each cylinder) at every ° / n.
F and outputs the unit pulse signal PO every 1-2 °.
S is output, and the engine speed Ne can be calculated from the period of the reference pulse signal REF and the like.

In addition, an air flow meter 13 for detecting an intake air flow rate Qa upstream of the throttle valve 4 in the intake passage 3,
Accelerator sensor 14 for detecting accelerator opening (accelerator pedal depression amount) ACC, opening TV of throttle valve 4
A throttle sensor 15 for detecting O (including an idle switch that is turned on when the throttle valve 4 is fully closed), a water temperature sensor 16 for detecting the cooling water temperature Tw of the engine 1, and a rich / lean exhaust air-fuel ratio in the exhaust passage 7. An O ₂ sensor 17 that outputs a signal according to the air conditioner, an air conditioner switch 18 and the like are provided.

Here, the control unit 10 as a control device of the engine receives signals from the various sensors and receives signals from the built-in microcomputer.
A predetermined calculation process is performed to control the throttle opening by the electronically controlled throttle valve 4, the fuel injection amount and injection timing by the fuel injection valve 5, and the ignition timing by the spark plug 6. Regarding the throttle control (control of the electronically controlled throttle valve 4), the target throttle opening tTVO is set according to the target torque of the engine set from the accelerator opening ACC and the engine speed Ne.
Is set, and the opening degree is controlled by driving the motor of the electronically controlled throttle valve 4 so as to obtain this.

For the fuel injection control (control of the fuel injection valve 5), a combustion method is set according to the engine operating conditions, and the fuel injection amount and the injection timing by the fuel injection valve 5 are controlled in accordance with the combustion method. More specifically, a map in which the combustion method is determined by using the engine speed Ne and the basic fuel injection amount Tp as parameters,
A plurality of water temperature Tw, time after starting, etc. are provided for each condition,
From the map selected from these conditions, the combustion method is set to one of homogeneous stoichiometric combustion, homogeneous lean combustion, or stratified lean combustion according to the parameters of the actual engine operating state.

In the case of homogeneous stoichiometric combustion as a result of the determination of the combustion method, the fuel injection amount is set to a value corresponding to the stoichiometric air-fuel ratio (14.6), and the air-fuel ratio feedback control by the O ₂ sensor 17 is performed. To the intake stroke,
Perform homogeneous stoichiometric combustion. In the case of the homogeneous lean combustion, the fuel injection amount is set to a value corresponding to the lean air-fuel ratio of the air-fuel ratio of 20 to 30, and the open control is performed, while the injection timing is set to the intake stroke to perform the homogeneous lean combustion. In the case of stratified lean combustion, the fuel injection amount is set to a value corresponding to a lean air-fuel ratio of about 40, and the open control is performed, while the injection timing is set to the compression stroke to perform the stratified lean combustion. .

Regarding the ignition control (control of the ignition plug 6),
The ignition timing ADV is set and controlled by referring to a map using the engine speed Ne and the basic fuel injection amount Tp as parameters for each combustion method. Further, the control unit 10 as a control device of the engine executes the torque signal generation routine of FIG. 3 and the torque signal transmission routine of FIG. As a result, signals for shift control and line pressure control are transmitted to the control device side of the transmission.

The torque signal generation routine shown in FIG. 3 will be described. This routine corresponds to engine output torque signal generation means. In S1, the accelerator opening ACC is detected based on a signal from the accelerator sensor 14. This part, together with the accelerator sensor 14, corresponds to an accelerator opening detecting means.

At S2, a driver request torque T1 corresponding to the accelerator opening is calculated. In other words, the detected accelerator opening ACC is converted to the driver request torque T1 corresponding to the accelerator opening ACC.
Convert to Specifically, the accelerator opening ACC is regarded as the throttle opening as it is, the throttle opening area at the throttle opening is obtained, and this throttle opening area may be treated as the driver required torque. Using the opening area conversion table, the accelerator opening degree ACC is converted into the driver required torque T1.
This part corresponds to the driver required torque conversion means.

At S3, an engine request torque T2 irrelevant to the driver request is calculated. Specifically, the correction torque at the time of cooling is set with reference to the table according to the engine cooling water temperature Tw. In addition, ON / OF of the air conditioner switch 18
In accordance with F, an auxiliary load correction torque is set. And
The correction torque for the cold engine and the correction torque for the auxiliary load torque are added, and the result is set as the engine required torque T2. This part corresponds to the engine required torque calculating means. It should be noted that the engine required torque may include an idle-up amount, an overheat-response amount, and the like in addition to the cold-time correction torque and the auxiliary device load correction torque.

In S4, the driver required torque T1 and the engine required torque T2 are added, and the target torque tTRQ = T
1 + T2 is calculated. This part corresponds to a target torque calculating means. In S5, the target torque equivalent throttle opening V
Calculate TVO. That is, the calculated target torque t
TRQ is converted into a throttle opening VTVO corresponding to this. Specifically, the target torque tTRQ is treated as a throttle opening area, and the throttle opening at the throttle opening area may be obtained. Therefore, the conversion table for the throttle opening-opening area is used in reverse to obtain the target torque tTRQ.
Q is converted into a throttle opening VTVO. This portion corresponds to the throttle opening equivalent value conversion means. Here, the target torque equivalent throttle opening TVO can also be referred to as a target torque equivalent accelerator opening.

The torque signal transmission routine shown in FIG. 4 will be described. In S11, various diagnoses are performed. As a specific example, the target throttle opening degree t of the electronically controlled throttle valve 4 is given.
A deviation between TVO and the actual throttle opening TVO is detected, and when it is equal to or higher than a predetermined level, it is diagnosed that there is an abnormality (NG).
Further, a fluctuation state of the engine speed Ne is detected, and even when the target torque does not change and a large rotation fluctuation occurs, it is diagnosed that there is an abnormality (NG). This part corresponds to a diagnosis unit.

In S12, the result of the diagnosis is determined, and the
In the case of K), S13 to S15 are executed, and in the case of abnormality (NG), S16 to S18 are executed. In the case of normal (OK), in S13, the accelerator opening ACC detected in S1
Is transmitted to the transmission as an accelerator opening signal. In S14, the target torque equivalent throttle opening VTVO calculated in S5 is transmitted to the transmission as an engine output torque signal. This part corresponds to the engine output torque signal transmitting means.

In step S15, an undefined state flag FNGTRQ = 0 (normal state) is transmitted as a diagnostic signal. In the case of abnormality (NG), in S16, the accelerator opening ACC detected in S1 is transmitted to the transmission as an accelerator opening signal. Further, in S17, instead of the throttle opening VTVO corresponding to the target torque calculated in S5, a predetermined fixed value MAXTVO on the torque maximum value side or the actual throttle opening TVO is sent to an engine output torque signal (fail-safe signal). Signal) to the transmission. This part corresponds to the engine output torque signal transmitting means and the torque signal replacing means.

In step S18, an undefined state flag FNGTRQ = 1 is transmitted as a diagnostic signal to indicate that the engine output torque signal is in an undefined state. This part corresponds to a diagnostic signal transmitting unit. FIG. 5 is a system diagram on the transmission side. A continuously variable transmission (CVT) 23 is connected to the output shaft 21 side of the engine via a clutch 22.

The continuously variable transmission 23 has a primary pulley 25 whose effective diameter on the input shaft 24 side can continuously change and a secondary pulley 27 whose output diameter on the output shaft 26 side (the differential side) can continuously change. , A belt 28 wound between these pulleys 25 and 27, a primary pressure (shift speed) is input, and a primary side cylinder 29 which acts on the primary pulley 25 in a radially increasing direction, and a line pressure is input. And a secondary side cylinder 30 acting on the secondary pulley 27 in the radially expanding direction.

Here, the line pressure input to the secondary side cylinder 30 is generated by a line pressure control valve 31 having a relief function using the hydraulic pressure of a hydraulic source such as an oil pump as a source pressure. The primary pressure input to the primary cylinder 29 is generated by the shift control valve 32 having a relief function using the line pressure as the original pressure.

Therefore, although the primary pressure is always lower than the line pressure, the pressure receiving area of the primary cylinder 29 is set to be larger than the pressure receiving area of the secondary cylinder 30, so that the ratio of the primary pressure to the line pressure (primary pressure / line pressure) By controlling the pressure, the pulley ratio can be changed, and the speed ratio can be changed steplessly. The duty of the line pressure control valve 31 and the shift control valve 32 is controlled by a control unit 33 as a control device of the transmission.

For this control, a signal is input to the transmission control unit 33 from a vehicle speed sensor 34 for detecting the vehicle speed VSP and the like, and an accelerator opening signal (from the engine control unit 10 via a communication line). ACC) and an engine output torque signal (VTVO or its fail-safe signal). The transmission control control unit 33 controls the transmission control valve 32 and the line pressure control valve 31 based on these signals by a built-in microcomputer according to the transmission control routine of FIG. Control.

The transmission control routine of FIG. 6 will be described. In S21, a target gear ratio is calculated based on the accelerator opening ACC and the vehicle speed VSP with reference to a gear shift map. In S22, the duty ratio of the shift control valve 32 is controlled so as to obtain the target gear ratio, and the primary pressure is controlled.

In step S23, a target line pressure is calculated by referring to a predetermined table based on the target torque equivalent throttle opening TTVO (or its fail-safe signal) as an engine output torque signal. In S24, the line pressure is controlled by duty-controlling the line pressure control valve 31 so as to obtain the target line pressure. Steps S23 and S24 correspond to the line pressure control means.

As described above, by controlling the line pressure on the transmission side based on the throttle opening TTVO corresponding to the target torque as the engine output torque signal, the line pressure control of the transmission can be ensured. it can. When the torque demand control is abnormal, the throttle opening TTVO corresponding to the target torque as the engine output torque signal may be in an indeterminate state. However, the engine sets an indeterminate state flag FNGTRQ indicating the indeterminate state. Not only is the transmission value transmitted to the transmission side, but also a predetermined fixed value MAXTVO on the maximum torque value side or the actual throttle opening TVO is replaced with the engine output torque instead of the throttle opening VTVO corresponding to the target torque. Since the signal is transmitted to the transmission as a signal (fail-safe signal), the transmission output can be regarded as a larger engine output torque, the line pressure can be controlled to be relatively large, and belt slippage due to insufficient line pressure can be avoided.

Although the actual throttle opening TVO is larger than the throttle opening TTVO corresponding to the target torque, the difference becomes remarkable especially in stratified combustion.

[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 of an internal combustion engine showing an embodiment of the present invention.

FIG. 3 is a flowchart of an engine-side torque signal generation routine.

FIG. 4 is a flowchart of an engine-side torque signal transmission routine.

FIG. 5 is a system diagram on the transmission side.

FIG. 6 is a flowchart of a transmission control routine.

[Explanation of symbols]

 Reference Signs List 1 internal combustion engine 4 electrically controlled throttle valve 5 fuel injection valve 6 ignition plug 10 control unit for engine control 11, 12 crank angle sensor 13 air flow meter 14 accelerator sensor 16 water temperature sensor 18 air conditioner switch 21 engine output shaft 22 clutch 23 stepless transmission (CVT) 25 Primary pulley 27 Secondary pulley 29 Primary side cylinder 30 Secondary side cylinder 31 Line pressure control valve 32 Shift control valve 33 Control unit for transmission control 34 Vehicle speed sensor

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/04 310 F02D 41/04 310G 41/22 310 41/22 310Z F16H 59/16 F16H 59/16

Claims (7)

[Claims] 1. An output control device for a vehicle for cooperatively controlling an internal combustion engine and a transmission, comprising: an engine output torque signal generating means for generating an engine output torque signal; An engine output torque signal transmitting means for transmitting an engine output torque signal is provided. On the other hand, a diagnosis result of the diagnosis means for diagnosing the abnormality of the engine control device is received. On the other hand, an output control device for a vehicle is provided with a diagnostic signal transmitting means for transmitting a signal indicating that an engine output torque signal is in an indeterminate state. 2. The engine output torque signal transmitting means receives a diagnosis result of a diagnosis means for diagnosing the presence or absence of an abnormality in a control device of the engine. 2. A torque signal replacing means for replacing the torque signal with the signal of (1).
The output control device for a vehicle as described in the above. 3. The output control device for a vehicle according to claim 2, wherein the fail-safe signal corresponds to a predetermined fixed value on the maximum torque value side. 4. The engine output torque signal generating means includes: a driver required torque converting means for converting an accelerator opening detected by an accelerator opening detecting means into a driver required torque; and an engine required torque irrelevant to the driver required. Means for calculating required engine torque, means for calculating target torque by adding the required driver torque and required engine torque, and means for converting throttle opening equivalent value to convert the target torque to a throttle opening equivalent value. The vehicle output control according to any one of claims 1 to 3, wherein a throttle opening equivalent value of a target torque is transmitted as an engine output torque signal. apparatus. 5. The engine output torque signal generating means includes a driver required torque converting means for converting an accelerator opening detected by an accelerator opening detecting means into a driver required torque, and an engine required torque irrelevant to the driver required. Means for calculating required engine torque, means for calculating target torque by adding the required driver torque and required engine torque, and means for converting throttle opening equivalent value to convert the target torque to a throttle opening equivalent value. And transmitting a throttle opening equivalent value of a target torque as an engine output torque signal, wherein the fail-safe signal corresponds to an actual throttle opening. The output control device for a vehicle according to claim 2. 6. The diagnostic means detects at least a deviation between a target throttle opening and an actual throttle opening of the electronically controlled throttle valve, and diagnoses that there is an abnormality when the difference is equal to or higher than a predetermined level. The vehicle output control device according to any one of claims 1 to 5, characterized in that: 7. The transmission control device according to claim 1, further comprising a line pressure control means for controlling a line pressure of the transmission based on an engine output torque signal. The output control device for a vehicle according to any one of the preceding claims.