JPH10299526A - Creep running control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a creep running control device capable of ensuring a creep speed almost agreeing with a driver's requirement. SOLUTION: In an intake passage 11 of an engine 1, a bypass passage 22 is provided, which bypasses a throttle valve 19 to make its upstream/downstream communicate with each other, in the halfway thereof, an idle speed control valve (ISCV) 23 is provided. In an electronic control device (ECU) 51, when acceleration operation is released, brake operation is released and an input/ output shaft of a transmission are connected, vehicle performs creep running, based on an output of the engine 1. Here, in the ECU 51, in accordance with a shift position, expected control of the ISCV 23 is performed, thereafter, so that an actual car speed obtains a target creep speed, the ISCV 23 is feedback controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a creep traveling control device, and more particularly, to an internal combustion engine when an accelerator operation and a brake operation are released and an input shaft and an output shaft of a transmission are connected. The present invention relates to a creep traveling control device for controlling the creep traveling of a vehicle based on the output of the vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been known a control for converging an idle speed of an engine to a target speed during idling of the engine. In this technology,
The accelerator pedal is not depressed by controlling the opening of an idle speed control valve (ISCV) provided in a bypass passage bypassing the throttle valve and connecting the upstream side and the downstream side of the throttle valve. In this state, the intake air amount of the engine is controlled to control the idle speed.

[0003] In addition, in Japanese Patent Application Laid-Open No. 60-19933, in addition to the above technique, when an input shaft and an output shaft of an automatic transmission are connected,
By increasing the engine speed from the target speed,
It is disclosed that the engine speed is reduced to a target speed at a constant rate thereafter. For example, when the shift position is set to the D (drive) range, a load is applied to the engine. The above technology takes that into account,
By performing the above-described control of increasing the engine speed, a decrease in the engine speed is suppressed, and the rotation speed is prevented from becoming unstable.

[0004]

However, the above prior art has the following problems. That is, when the shift position is set to, for example, the D (drive) range (in the case of gear-in), when the brake operation is released, the output accompanying the rotation of the engine is transmitted to the vehicle, and the vehicle is creeped. Start running. Such creep traveling is performed, for example, when the driver tries to gradually start the stopped vehicle. At this time, if only the engine speed is controlled as in the above technique, the creep running speed may be different depending on the operating state of the engine or the situation of the vehicle at that time. Was.

[0005] For example, when the vehicle is on an uphill, the creep speed becomes almost zero, and when the vehicle is on a downhill, there is a possibility that the creep speed exceeds a speed expected by the driver. Was. In addition, when the shift position is set to the R (reverse) range, there is a possibility that the creep speed may be higher than when the shift position is set to the D range. Further, in a vehicle equipped with a manual transmission, the traveling speed is different between the case of creeping at the first speed and the case of creeping at the second speed. There was even fear of. As described above, the traveling speed differs depending on the state at that time, and as a result, there is a possibility that the creep traveling requested by the driver may be hindered.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a creep traveling control device capable of securing a creep speed substantially in accordance with a driver's request.

[0007]

According to a first aspect of the present invention, an accelerator operation is released, a brake operation is released, and a transmission mounted on a vehicle is provided. A creep travel control device for controlling the creep travel of the vehicle based on the output of the internal combustion engine when the input shaft and the output shaft of the internal combustion engine are coupled to each other for adjusting the output of the internal combustion engine. Output adjusting means, detecting means for detecting a parameter corresponding to the traveling speed of the vehicle, and controlling the output adjusting means based on the parameters detected by the detecting means so as to obtain a substantially constant target creep speed. The gist of the present invention is to provide an output control unit that performs the control.

According to a second aspect of the present invention, in the creep traveling control device according to the first aspect, the output control means controls the output so as to obtain a substantially constant target creep speed based on a parameter. The gist is that feedback control of the adjusting means is performed.

Further, according to the third aspect of the present invention, in the creep traveling control device according to the second aspect,
A state detecting means for detecting an operating state of the internal combustion engine or a running state of the vehicle at that time, and the output control means changes a target creep speed based on a detection result of the state detecting means. The gist is that

According to a fourth aspect of the present invention, in the creep traveling control device according to the third aspect, the output control means detects the detection result of the state detection means in a stage before executing the feedback control. The gist is that the output adjustment means is prospectively controlled based on the above.

In addition, according to the invention described in claim 5, in the creep traveling control device according to any one of claims 1 to 4, the state detected by the state detecting means includes a gear position of the transmission, a road position, and a road. The gist is that it is at least one of a gradient, a road surface condition, and a load applied to the internal combustion engine.

Furthermore, in the invention according to claim 6,
6. The creep running control device according to claim 1, wherein the output adjusting unit adjusts an intake air amount of the internal combustion engine, a unit that adjusts a fuel injection amount of the internal combustion engine, and the internal combustion engine. The gist of the invention is that it is constituted by at least one of means for adjusting the ignition timing of the engine.

According to the first aspect of the present invention, the accelerator operation is released, the brake operation is released, and the input shaft and the output shaft of the transmission mounted on the vehicle are connected. If so, the vehicle performs creep running based on the output of the internal combustion engine.

In the present invention, the detection means detects a parameter corresponding to the running speed of the vehicle. Then, the output control means controls the output adjusting means based on the detected parameters, and a substantially constant target creep speed is obtained.

According to a second aspect of the present invention, in addition to the operation of the first aspect, the output control means controls the substantially constant target creep speed based on the detected parameter. The output adjustment means is feedback controlled so as to obtain Therefore, a more stable creep speed can be obtained.

Further, according to the third aspect of the present invention,
In addition to the effect of the invention described in claim 2, the operating state of the internal combustion engine and the running state of the vehicle at that time are further detected by the state detecting means. Then, the target creep speed is changed by the output control means based on the detection result of the state detection means. Therefore, an appropriate creep speed according to the state at that time can be obtained.

Further, according to the invention described in claim 4,
In addition to the effect of the third aspect of the present invention, in a stage before executing the feedback control, the output control means first performs prospective control on the output adjustment means based on the detection result of the state detection means. Therefore, an appropriate creep speed according to the state at that time can be obtained earlier.

[0018] In addition, according to the invention of claim 5,
In addition to the operation of the invention as set forth in claims 1 to 4, the creep speed is controlled in accordance with the conditions such as the gear position of the transmission, road gradient, road surface condition, and the load applied to the internal combustion engine.

According to a sixth aspect of the present invention, in addition to the function of any one of the first to fifth aspects, means for adjusting the intake air amount of the internal combustion engine, By controlling at least one of the means for adjusting the fuel injection amount and the means for adjusting the ignition timing of the internal combustion engine, the creep speed is controlled.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of a creep traveling control device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a creep traveling control device in an engine system as an internal combustion engine mounted on a vehicle (automobile) in the present embodiment.
An engine 1 mounted on an automobile has a plurality of cylinders, and a cylinder block 2 constituting the engine 1 has cylinder bores 3 corresponding to the number of cylinders. Cylinder block 2
A cylinder head 4 is mounted on the upper side of the cylinder so as to close each cylinder bore 3. A piston 5 is provided in each cylinder bore 3 so as to be vertically movable, and the piston 5 is connected to a crankshaft (not shown) via a connecting rod 6. Further, inside the cylinder bore 3, a space surrounded by the piston 5 and the cylinder head 4 is a combustion chamber 7.

The cylinder head 4 is provided with an ignition plug 8 corresponding to each of the combustion chambers 7. Also,
The cylinder head 4 is provided with an intake port 9 and an exhaust port 10 communicating with each combustion chamber 7, respectively. An intake passage 11 and an exhaust passage 12 are connected to each of the ports 9, 10, respectively. And the intake port 9
And an intake passage 11 and the like constitute an intake system. Furthermore, an opening / closing intake valve 13 and an exhaust valve 14 are provided at each open end of the intake port 9 and the exhaust port 10 communicating with the combustion chamber 7. The intake valve 13 and the exhaust valve 14 are opened and closed in conjunction with the rotation of a crankshaft by a valve train including a camshaft (not shown). The opening and closing timings of these valves 13 and 14 are opened and closed in synchronization with the rotation of the crankshaft.

An air cleaner 1 is provided on the inlet side of the intake passage 11.
5 are provided. In the middle of the intake passage 11,
A surge tank 16 for smoothing the pulsation of the air passing through the passage 11 is provided. Further, on the downstream side of the surge tank 16, in the vicinity of the intake port 9 for each cylinder, an injector 17 as a fuel injection means is provided. Fuel of a predetermined pressure is supplied to these injectors 17 from a fuel tank (not shown) by a fuel pump. On the other hand, on the outlet side of the exhaust passage 12, a catalytic converter 18 having a built-in three-way catalyst for purifying exhaust gas is provided.

The engine 1 has an air cleaner 15.
Is taken in through the intake passage 11 including the surge tank 16. Further, when fuel is injected from each injector 17 simultaneously with the introduction of the outside air, a mixture of the outside air and the fuel is taken into the combustion chamber 7 in synchronization with the opening of the intake valve 13 in the intake stroke. Further, when the air-fuel mixture taken into the combustion chamber 7 is ignited by the spark plug 8, the air-fuel mixture explodes and burns, so that the engine 1 can obtain a driving force. The exhaust gas after the explosion and combustion is guided to the exhaust passage 12 in synchronization with the opening of the exhaust valve 14 in the exhaust stroke, and is discharged from the exhaust passage 12 to the outside through the catalytic converter 18 and the like.

An upstream side of the surge tank 16 is provided with a throttle valve 19 that opens and closes in response to operation of an accelerator pedal (not shown). By opening and closing the throttle valve 19, the amount of outside air taken into the intake passage 11, that is, the intake air amount Q is adjusted.
In the vicinity of the throttle valve 19, a throttle sensor 31 for detecting the opening of the valve 19, that is, the throttle opening TA is provided. This throttle sensor 31 outputs a signal of the throttle opening degree TA. A fully closed switch 42 is provided adjacent to the throttle sensor 31. The fully closed switch 42 outputs an ON signal only when the throttle valve 19 is at the fully closed position. On the downstream side of the air cleaner 15, there is provided an air flow meter 32 for detecting an intake air amount Q to the intake passage 11. Air cleaner 1
Between the air flow meter 5 and the air flow meter 32, an intake air temperature sensor 33 for detecting the temperature of the air taken into the intake passage 11, that is, the intake air temperature THA is provided.

Further, an oxygen sensor 34 for detecting the oxygen concentration in the exhaust gas, that is, for detecting the exhaust air-fuel ratio in the exhaust gas passage, is provided in the exhaust passage 12. Further, the cylinder block 2 is provided with a water temperature sensor 35 for detecting the temperature of the cooling water of the engine 1, that is, the cooling water temperature THW.

The ignition signal distributed by the distributor 20 is applied to the ignition plug 8 for each cylinder. The distributor 20 distributes the high voltage output from the igniter 21 to each ignition plug 8 in synchronization with the rotation of the crankshaft, that is, the crank angle. The ignition timing of each ignition plug 8 is determined by the high voltage output timing from the igniter 21.

The distributor 20 has a built-in rotor (not shown) that rotates in conjunction with the rotation of the crankshaft. And the distributor 20
A rotation speed sensor 36 for detecting the rotation speed of the engine 1, that is, the engine rotation speed NE from the rotation of the rotor is provided. Similarly, the distributor 20 is provided with a cylinder discrimination sensor 37 that detects a crank angle reference signal GP of the engine 1 at a predetermined rate according to the rotation of the rotor. In this embodiment, the crankshaft makes two rotations for a series of strokes in the engine 1,
The rotation speed sensor 36 detects the crank angle at a rate of 30 ° CA per pulse. The cylinder discrimination sensor 37 is 1
The crank angle is detected at a rate of 360 ° per pulse.

Further, the vehicle is provided with an automatic transmission (not shown) that can be drivingly connected to the engine 1. When an input shaft and an output shaft of the transmission are connected, the output of the engine 1 is transmitted to the vehicle. The transmitted and positive running of the vehicle is allowed. The automatic transmission is provided with a vehicle speed sensor 38 for detecting the speed of the vehicle, that is, a vehicle speed SPD (in the present embodiment, a means for detecting a parameter corresponding to the vehicle speed is configured by the vehicle speed sensor 38). ing). Similarly, the automatic transmission is provided with a shift position sensor 40 for detecting a shift position (D range, R range, N (neutral) range, etc.) at that time.

In the present embodiment, the intake passage 11 bypasses the throttle valve 19 and
Passage 2 that connects the upstream side and the downstream side to each other
2 are provided. In the middle of the bypass passage 22, a well-known linear solenoid type idle speed control valve (ISCV) 23 is provided. The ISCV 23 is driven and controlled based on a predetermined control signal, so that the bypass passage 22 is opened and closed. The ISCV 23 is operated to stabilize the idling of the engine 1 when the throttle valve 19 is fully closed at the time of idling, and constitutes an intake air amount adjusting means in the present embodiment. Therefore, when the opening of the ISCV 23 and the valve opening time thereof are controlled when the engine 1 is idling,
By performing the SC control, the amount of air flowing through the bypass passage 22 is adjusted, and the amount Q of intake air to the combustion chamber 7 is adjusted.
As a result, the engine output including the engine speed NE is adjusted.

The engine 1 is provided with a starter 24 for applying a rotational force to the engine 1 by cranking at the time of starting. The starter 24 has a starter switch 39 for detecting its operation / non-operation.
Is provided. The starter switch 39 is turned on / off by the operation of an ignition switch (not shown). Since the starter 24 is operated while the ignition switch is being operated, the starter switch 39 outputs an “ON” starter signal. STS is output.

Further, a brake sensor 41 is provided on the brake pedal 25. The brake sensor 41
Outputs an ON signal when the brake pedal 25 is depressed or the side brake is operated.

Each injector 17, igniter 21, and ISCV 23 are connected to an electronic control unit (hereinafter simply referred to as “EC
U ”) 51, and their drive timing is controlled by the operation of the ECU 51. This ECU 51 constitutes output control means,
Reference numeral 51 denotes the aforementioned throttle sensor 31, air flow meter 32, intake air temperature sensor 33, oxygen sensor 34, water temperature sensor 35, rotation speed sensor 36, cylinder discrimination sensor 37, vehicle speed sensor 38, starter switch 39, shift position sensor 40, brake The sensor 41 and the fully closed switch 42 are respectively connected. The ECU 51 controls each injector 17, the igniter 21, and the ISC based on output signals from the sensors 31 to 42 and the like to control the ignition timing of the engine 1, the fuel injection amount, the ISC control, and the like.
V23 is suitably driven and controlled.

Next, the electrical configuration of the ECU 51 will be described with reference to the block diagram of FIG. The ECU 51 includes a central processing unit (CPU) 52, a read-only memory (ROM) 53 in which a predetermined control program and the like are stored in advance, and a random access memory (RA) for temporarily storing the calculation results of the CPU 52 and the like.
M) 54, Backup R for storing stored data
An AM 55, a timer counter 56, and the like, and a logical operation circuit formed by connecting these components to an external input circuit 57, an external output circuit 58, and the like via a bus 59.
In the present embodiment, the ROM 53 stores in advance control programs such as a “creep speed control routine” described later, a map of ignition timing, injection timing control, and the like. The timer counter 56 outputs an interrupt signal every predetermined time and simultaneously performs a plurality of counting operations.

The external input circuit 57 includes the above-described throttle sensor 31, air flow meter 32, and intake air temperature sensor 3.
3, oxygen sensor 34, water temperature sensor 35, rotation speed sensor 3
6. Cylinder discrimination sensor 37, vehicle speed sensor 38, starter switch 39, shift position sensor 40, brake sensor 4
1 and a fully closed switch 42 are connected to each other.
Further, the injector 17, the igniter 21, the ISCV 23, and the like are connected to the external output circuit 58.

Then, the CPU 52 reads, as input values, signals from the sensors 31 to 42 and the like input via the external input circuit 57. Further, the CPU 51 suitably controls the driving of the injectors 17, the igniter 21, the ISCV 23 and the like based on the read input values.

The ISCV 23 is controlled by an electromagnetic solenoid driven by a duty control signal.
The opening area is controlled, and the adjustment of the intake air amount in the present embodiment is performed by using the ISCV 23. Then, the ECU 51
Number of rotations of engine 1 (engine output in the present embodiment)
To control the opening of the ISCV 23 (ISC opening AISC)
As a result, a duty ratio for controlling the ISCV 23 based thereon is calculated.

Next, the contents of control in the creep running control device configured as described above will be described with reference to the flowchart shown in FIG. That is, the flowchart shown in FIG. 3 shows the “creep speed control routine” executed by the ECU 51, and is executed by interruption every predetermined crank angle. Note that the ECU 51
At the timing of an interrupt signal output from the timer counter 56 at predetermined time intervals, signals from the various sensors 31 to 42 and the like are repeatedly read.

When the processing shifts to this routine, the ECU
51 determines in step 101 whether or not the fully closed switch 42 outputs an ON signal. That is, it is determined whether the driver has depressed the accelerator pedal. Then, when the accelerator pedal is operated, it is determined that creep running has not been requested, and the subsequent processing is temporarily terminated.

On the other hand, when the accelerator pedal is not depressed (when the fully-closed switch 42 outputs an ON signal), in the next step 102, based on the detection signal from the brake sensor 41, It is determined whether or not a brake operation has been performed. Then, even when the brake operation is performed, it is determined that the creep running is not requested, and the subsequent processing is temporarily ended.

On the other hand, if the brake operation has not been performed, as long as the input shaft and the output shaft of the transmission are connected, it is determined that creep running has been requested, and the routine proceeds to step 103. Step 1
In 03, based on the detection signal of the shift position sensor 40, it is determined whether or not the current shift position is in the D range. If the current shift position is in the D range, it is determined that creep running ahead of the vehicle has been requested, and the process proceeds to step 104.

Then, at step 104, the ECU
Reference numeral 51 denotes an ISC opening AI for the time being to perform prospect control.
SC is set to a predetermined value α. After that, Step 1
At 05, the ISCV 23 is feedback-controlled so that the actual vehicle speed SPD becomes the target creep speed S1 for the D range, and the subsequent processing is temporarily terminated.

If the current shift position is not in the D range in step 103, step 10
At 6, it is determined whether or not the current shift position is in the R range. If the current shift position is in the R range, it is determined that creep running backward of the vehicle has been requested, and the routine proceeds to step 107.

Then, at step 107, the ECU
Reference numeral 51 denotes an ISC opening AI for the time being to perform prospect control.
SC is set to a predetermined value β. The predetermined value β is smaller than the predetermined value α, so that the opening of the ISCV 23 becomes smaller when the current shift position is in the R range than in the D range. , The engine speed NE and, consequently, the vehicle speed SPD are small.
Thereafter, in step 108, the actual vehicle speed S
PD is the target creep speed S2 for the R range (S2 <S
ISCV 23 is feedback-controlled so as to satisfy 1),
Thereafter, the processing is temporarily terminated.

Further, in step 106, if the current shift position is not in the R range, it is determined that creep running is not particularly requested, and the subsequent processing is temporarily terminated without performing any processing. .

As described above, in the "creep speed control routine", when creep running is requested, prospective control of the vehicle speed SPD according to the shift position at that time and feedback control thereafter are executed.

Next, the operation and effect of this embodiment will be described. In the present embodiment, when the accelerator operation is released, the brake operation is released, and the input shaft and the output shaft of the transmission are connected, the vehicle is controlled based on the output of the engine 1. Perform creep running. In particular, in the present embodiment, the actual vehicle speed SPD is D
The ISCV 23 is feedback-controlled to achieve the target creep speeds S1 and S2 for the range or the R range. Therefore, creep traveling can be performed at a creep speed corresponding to each shift position. As a result, it is possible to secure a creep speed substantially in accordance with the driver's request.

In the present embodiment, the target creep speed is changed according to the shift position at that time. That is, feedback control is performed so that the vehicle speed SPD becomes the target creep speed S1 in the D range, and the vehicle speed SPD becomes the target creep speed S2 in the R range. Therefore, it is possible to obtain an appropriate creep speed according to the state at that time.

Further, at the stage before executing the feedback control, first, the anticipation control is executed. That is, in the case of the D range, the ISC opening AISC is equal to the predetermined value α.
In the case of the R range, the ISC opening AISC is set to a predetermined value β. Therefore, an appropriate creep speed according to the state at that time can be obtained earlier. Also, at the time of anticipation control, the ISC opening AISC is made different depending on the shift position. Therefore, an appropriate creep speed according to the state at that time can be obtained more quickly.

(Second Embodiment) Next, a second embodiment of the present invention will be described. However, since the configuration and the like of this embodiment are the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof is omitted. And, below, the first
The following description focuses on differences from the first embodiment.

In the above-described first embodiment, the ISCV 23 is used as a means for adjusting the intake air amount of the engine 1, and this is used as the output adjustment means of the engine 1. On the other hand, in the present embodiment, not only the above ISCV23,
The injector 17 as the means for adjusting the fuel injection amount and the igniter 21 as the means for adjusting the ignition timing also differ from the first embodiment in that they constitute the output adjusting means. That is, the present embodiment is characterized in that the output adjusting means is selectively used in accordance with the creep running speed after performing the prospective control in the first embodiment.

FIG. 4 is a flowchart showing a "creep speed control routine" executed by the ECU 51, which is executed by interruption every predetermined crank angle. In addition,
This flowchart shows the control contents after performing the prospective control (step 104) of the first embodiment, for example, when the shift position is in the D range for convenience.

After performing the anticipation control, the ECU 51 determines in step 201 the target creep speed S1 in the D range and the current vehicle speed SPD after a predetermined time has elapsed since the anticipation control was performed (or may be immediately after the anticipation control). Is determined.

Next, in step 202, it is determined whether or not the deviation ΔSPD obtained this time is larger than, for example, “5 km / h”. The deviation ΔSPD is “5 km
/ H ”, the target creep speed S
It is determined that the distance from 1 is large, and step 203
, The opening of the ISCV 23 is feedback-controlled so that the actual vehicle speed SPD becomes the target creep speed S1. Then, the subsequent processing ends once.

If it is determined in step 202 that the deviation ΔSPD obtained this time is not larger than “5 km / h”, the process proceeds to step 204. In step 204, the deviation ΔSPD obtained this time is, for example, “3 km /
It is determined whether it is within the range of not less than “h” and not more than “5 km / h”. If the deviation ΔSPD is within the above range, it is determined that the distance from the target creep speed S1 is medium, and in step 205, the actual vehicle speed SP
The fuel injection amount TA such that D becomes the target creep speed S1
U, that is, feedback control of the injector 17 is performed. Then, the subsequent processing ends once.

Further, in step 204, the deviation ΔSPD obtained this time is not less than “3 km / h” and “5 km / h”.
If not, the process proceeds to step 206. In step 206, the deviation ΔSP determined this time
D is less than “3 km / h” and the target creep speed S
It is determined that the distance from 1 is small.
, The ignition timing advance amount θ, that is, the igniter 2 so that the actual vehicle speed SPD becomes the target creep speed S1.
1 is feedback-controlled. Then, the subsequent processing ends once.

As described above, in the present embodiment, the output adjustment means to be controlled is selectively used based on the deviation ΔSPD between the vehicle speed SPD after performing the prospective control and the target creep speed S1.

Here, as shown in FIGS. 5 (a), 5 (b) and 5 (c), generally, changing the fuel injection amount TAU is better than changing the ignition timing advance amount θ. The effect on the engine output T is large. That is, the engine output T fluctuates more greatly when the fuel injection amount TAU is changed to the maximum than when the advance angle θ is changed to the maximum. Also, rather than changing the fuel injection amount TAU, the ISC opening AIS
Changing C has a greater effect on engine output T. That is, the engine output T tends to fluctuate more greatly when the ISC opening AISC is changed to the maximum than when the fuel injection amount TAU is changed to the maximum.

For this reason, as described above, when the deviation ΔSPD is large in the feedback control, the actual vehicle speed SPD becomes the target creep speed S1 earlier by performing the feedback control of the ISC opening AISC. Further, when the deviation ΔSPD is large, more delicate control is possible by performing feedback control of the advance angle θ.
Therefore, according to the present embodiment, it can be said that controllability can be further improved.

The present invention is not limited to the above-described embodiment, but may be implemented as follows, with a part of the configuration being appropriately changed without departing from the spirit of the invention. (1) In each of the above embodiments, the present invention is embodied in a vehicle equipped with an automatic transmission. However, the present invention may be embodied in a vehicle equipped with a manual transmission.

(2) In the first embodiment, if the shift position is in the D range and the R range, the ISC opening AISC when performing the prospective control and the target creep speeds S1 and S2 in the feedback control are different. I tried to make it. On the other hand, other shift positions (for example, 2nd range) may be considered. In a vehicle equipped with a manual transmission as in (1) above, the control amount may be made different depending on the first speed, the second speed, and the like.

(3) Further, in the above-mentioned embodiment, the control other than the control in accordance with the shift position is not mentioned. However, besides the above, the road gradient (uphill / downhill) and the road surface condition (low μ road)・ High μ road), other loads applied to the engine 1 (electric loads such as air conditioners and headlights, loads due to power steering, etc.), or the engine speed NE immediately before creeping.
The control amount (expected control amount, target creep speed at the time of feedback control) may be changed according to the above. In addition, these factors may be appropriately combined and considered.

(4) In the above embodiment, the prospective control is executed as a stage prior to the feedback control. However, such control may be omitted. (5) In the second embodiment, based on the deviation ΔSPD between the vehicle speed SPD after performing the prospective control and the target creep speed S1, the target of the feedback control is set to the advance amount θ of the ignition timing, the fuel injection Amount TAU, ISC opening AI
Although the SCs are selectively used, actuators other than the SCs may be controlled. For example, in the case of a type having an electronically controlled throttle valve, the above I
Instead of the SCV 23, the opening of the throttle valve can be controlled.

Further, various actuators may be appropriately combined. By employing such a combination, delicate control can be further performed according to the state of the engine and the like.

(6) In the above embodiment, the vehicle speed sensor 3
8, the vehicle speed SPD is directly detected. However, a parameter corresponding to the vehicle speed may be obtained indirectly from the engine speed NE and the gear ratio, and control may be performed based on this.

[0066]

As described in detail above, the creep traveling control device of the present invention has an unprecedented excellent effect that a creep speed substantially in accordance with the driver's request can be secured.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a creep traveling control device in an engine system mounted on an automobile.

FIG. 2 is a block diagram showing an electrical configuration of an ECU.

FIG. 3 is a flowchart illustrating a “creep speed control routine” executed by an ECU in the first embodiment.

FIG. 4 is a flowchart illustrating a part of a “creep speed control routine” executed by an ECU according to the second embodiment.

FIG. 5 is a graph showing the amount of change in engine output for each control object in the second embodiment, where (a) is an ISC;
The relationship between the engine output and the opening degree is shown, (b) shows the relationship between the engine output and the fuel injection amount, and (c) shows the relationship between the engine output and the advance amount of the ignition timing.

[Explanation of symbols]

1. Engine as internal combustion engine, 8. Spark plug, 17
... injector, 19 ... throttle valve, 21 ... igniter, 22 ... bypass passage, 23 ... idle speed control valve (ISCV), 25 ... brake pedal, 31 ... throttle sensor, 32 ... air flow meter, 33 ... intake air temperature sensor, 34 ... Oxygen sensors 34, 35
... water temperature sensor, 36 ... rotation speed sensor, 37 ... cylinder discrimination sensor, 38 ... vehicle speed sensor, 39 ... starter switch, 4
0: shift position sensor, 41: brake sensor, 42:
Fully closed switch, 51 ... ECU.

Claims (6)

[Claims] When an accelerator operation is released, a brake operation is released, and an input shaft and an output shaft of a transmission mounted on a vehicle are connected, based on an output of an internal combustion engine. A creep traveling control device for controlling creep traveling of the vehicle, an output adjusting unit for adjusting an output of the internal combustion engine; a detecting unit for detecting a parameter corresponding to a traveling speed of the vehicle; Based on the parameters detected by the detection means,
Output control means for controlling the output adjusting means so as to obtain a substantially constant target creep speed. 2. The creep according to claim 1, wherein the output control means performs feedback control of the output adjustment means based on a parameter such that a substantially constant target creep speed is obtained. Travel control device. 3. The creep traveling control device according to claim 2, further comprising state detection means for detecting an operating state of the internal combustion engine or a traveling state of the vehicle at that time, and the output control means. Is a device for changing a target creep speed based on a detection result of the state detecting means. 4. The creep traveling control device according to claim 3, wherein the output control means controls the output adjustment means based on a detection result of the state detection means at a stage before executing the feedback control. A creep travel control device characterized by performing 5. The state detected by the state detecting means is at least one of a gear position of the transmission, a road gradient, a road surface condition, and a load applied to the internal combustion engine. 5. The creep travel control device according to any one of 1 to 4. 6. The output adjusting means includes at least one of a means for adjusting an intake air amount of the internal combustion engine, a means for adjusting a fuel injection amount of the internal combustion engine, and a means for adjusting an ignition timing of the internal combustion engine. The creep traveling control device according to any one of claims 1 to 5, wherein