JPH06330779A - Output control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To secure power performance corresponding to requirement of a driver by preventing deterioration of drivability following abrupt change of an output in case failure occurs in a vehicle running condition detecting means. CONSTITUTION:A sub-throttle valve 8 which is opened and closed by the operation of a step motor 11 and a link type main throttle valve 9 are serially arranged in an intake passage 2. A throttle ECU 52 performs slip-prevention control in case failure does not occur at speed sensors 39L, 39R, 40L, 40R of a respective vehicles and the slip-prevention control is required. In case slip- preventive control is normally completed, the sub-throttle valve 8 is opened in a comparatively speedy manner. In case failure occurs in one of the speed sensors 39L, 39R, 40L, 40R, the slip-preventive control is completed and the sub-throttle valve 8 is opened in a comparatively slow manner. It is thus possible to prevent an output of an engine from lowering at the time of failure, and also prevent the output from abruptly changing.

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 an internal combustion engine, and for example, drives and controls output adjusting means such as a throttle valve provided in an intake system of the internal combustion engine in accordance with a preset control pattern. The present invention relates to an output control device that controls the output of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as this type of technique, for example, one disclosed in Japanese Patent Laid-Open No. 3-111634 is known. This technology discloses an electronically controlled throttle valve system having two control patterns of constant speed traveling and slip traveling of a vehicle. Then, when slip is detected based on the detection result from the wheel speed sensor during the constant speed traveling as described above, the slip ratio is set according to the slip state at that time. Based on this slip ratio, the target opening of the throttle valve is set to be smaller than before, for example. As a result, the output of the engine is reduced, and an appropriate driving force is secured for the wheels.

[0003]

However, in general, in the case where the wheel speed sensor or the like fails, including the above-mentioned conventional technique, the above control is temporarily terminated. Then, the throttle valve is drive-controlled so as to have a predetermined opening degree for the time being so that the engine output becomes a predetermined value. At this time, when the throttle valve is controlled so that the engine output becomes relatively large, the driving speed of the throttle valve may be too fast, and the engine output, that is, the torque may suddenly change. In such a case, the driver may feel uncomfortable, and as a result, drivability may be deteriorated.

Further, when the throttle valve is controlled so that the engine output becomes relatively small, the output cannot be obtained even if the driver requests a high output characteristic. As a result, even if the accelerator pedal is strongly depressed, the power performance (acceleration feeling) required by the driver may not be obtained.

The present invention has been made in view of the above-mentioned circumstances, and an object of the first invention is to set a plurality of preset control patterns of an internal combustion engine based on the detection result of the vehicle running state detecting means. In an output control device for an internal combustion engine, which is used properly to obtain a control characteristic based on the control pattern, it is possible to prevent deterioration of drivability due to a sudden change in output even if the vehicle running state detection means fails. Another object of the present invention is to provide an output control device for an internal combustion engine.

A second object of the present invention is to use a plurality of preset control patterns of the internal combustion engine based on the detection result of the vehicle running state detecting means and obtain a control characteristic based on the control pattern. In an output control device for an internal combustion engine, the output control device for an internal combustion engine is capable of ensuring power performance that meets a driver's request even when the vehicle traveling state detection means fails. .

[0007]

In order to achieve the above object, in the first invention, as shown in FIG. 1, an output adjusting means M2 for adjusting the output of the internal combustion engine M1, and
Output adjustment drive means M3 that is drive-controlled to operate the output adjustment means M2, vehicle running state detection means M4 that detects the running state of a vehicle equipped with the internal combustion engine M1, and detection results of the vehicle running state detection means M4 Based on the above, by properly using a plurality of preset control patterns of the internal combustion engine M1,
In an output control device for an internal combustion engine, which comprises a drive control means M5 for controlling the output adjustment drive means M3 so as to obtain a control characteristic based on the control pattern, a failure detection means for detecting a failure of the vehicle running state detection means M4. M6, a failure time selection means M7 for selecting a predetermined control pattern from a plurality of control patterns when a failure is detected by the failure detection means M6, and a vehicle traveling state detection means M.
No. 4, at the time of failure, from the state in which the output adjustment drive means M3 is drive-controlled by a control pattern different from the control pattern selected by the failure time selection means M7, the failure time selection means M7
The output adjustment drive means M3 with the control pattern selected by
Output adjustment drive means M3 when changing to a state in which the drive control is performed.
The change speed of the output adjustment drive means M3 is controlled in a control pattern different from the control pattern selected by the failure time selection means M7 when the vehicle traveling state detection means M4 is not in a failure state. The gist is to provide the failure change speed reducing means M8 for making the speed smaller than the change speed of the output adjustment drive means M3 when the output adjustment drive means M3 is driven and controlled by the control pattern selected by M7. I am trying.

In the second aspect of the invention, as shown in FIG. 2, an output adjusting means M2 for adjusting the output of the internal combustion engine M1 and an output adjustment for drivingly controlling the output adjusting means M2. A drive means M3, a vehicle running state detecting means M4 for detecting a running state of a vehicle equipped with the internal combustion engine M1, and a plurality of preset control patterns of the internal combustion engine M1 based on the detection results of the vehicle running state detecting means M4. In the output control device of the internal combustion engine, which includes the drive control means M5 for controlling the output adjustment drive means M3 so as to obtain the control characteristic based on the control pattern. And a characteristic of the output of the internal combustion engine M1 having the largest output of the plurality of control patterns when the failure is detected by the failure detection means M6. And the as its gist that the control pattern is provided with the maximum output pattern selecting means M9 for selecting with.

[0009]

According to the structure of the first aspect of the invention described above, as shown in FIG. 1, the output adjusting means M2 operates by the drive control of the output adjusting drive means M3, and adjusts the output of the internal combustion engine M1. To do. Further, the traveling state of the vehicle is detected by the vehicle traveling state detecting means M4. Then, based on the detection result, the drive control means M5 selectively uses a plurality of preset control patterns of the internal combustion engine M1 to drive-control the output adjustment drive means M3. Therefore, the control characteristic based on the control pattern is obtained.

Here, when the vehicle traveling state detecting means M4 fails, the failure detecting means M6 detects the failure, and the failure selecting means M7 determines a predetermined control pattern among a plurality of control patterns. To be selected. At this time, when the vehicle traveling state detecting means M4 fails, the failure selecting means M7 selects from a state in which the output adjustment driving means M3 is driven and controlled by a control pattern different from the control pattern selected by the failure selecting means M7. The change speed of the output adjustment drive means M3 when changing to the state in which the output adjustment drive means M3 is driven and controlled by the different control pattern is determined by the failure change speed reduction means M8 by the vehicle traveling state detection means M4.
When there is no failure, the output adjustment drive means M3 is driven and controlled by a control pattern different from the control pattern selected by the failure selection means M7, and the output adjustment drive is performed by the control pattern selected by the failure selection means M7. It becomes smaller than the changing speed of the output adjustment driving means M3 at the time of changing to the state of controlling the driving of the means M3. Therefore, even if the vehicle traveling state detecting means M4 fails, the operating speed of the output adjusting means M2 becomes relatively low, and the sudden change in the output of the internal combustion engine M1 is suppressed.

In the second aspect of the invention, as shown in FIG. 2, when the vehicle traveling state detecting means M4 fails, the failure detecting means M6 detects the failure and the maximum output pattern selecting means M9. The control pattern having the largest output of the internal combustion engine M1 is selected from the plurality of control patterns. Therefore, even if the operating state detecting means M4 fails, the output does not become small and a large output characteristic can be obtained.

[0012]

【Example】

(First Embodiment) A first embodiment of the output control device for an internal combustion engine according to the present invention will be described below in detail with reference to FIGS.

FIG. 3 is a schematic configuration diagram showing a gasoline engine system in which the output control device for an internal combustion engine according to the present invention is applied to throttle valve control of a front engine / rear drive system (FR system) vehicle. An engine 1 as an internal combustion engine mounted on a vehicle includes an intake passage 2 that constitutes an intake system and an exhaust passage 3 that constitutes an exhaust system. An air cleaner 4 is provided on the inlet side of the intake passage 2. The downstream side of the intake passage 2 is communicated with each cylinder (four cylinders in this embodiment) of the engine 1 through a branched intake manifold 2a. An injector 5 for fuel injection is provided near the intake manifold 2a.
A, 5B, 5C and 5D are provided corresponding to the respective cylinders. As is well known, the injectors 5A to 5D are supplied with fuel at a predetermined pressure from a fuel tank (not shown) by the operation of a fuel pump. Further, spark plugs 6A, 6B, 6C and 6D are provided in each cylinder of the engine 1. On the other hand, the exhaust passage 3 is connected to each cylinder of the engine 1 through a branched exhaust manifold 3a. A catalytic converter 7 including a three-way catalyst is provided on the outlet side of the exhaust passage 3.

In the above structure, the engine 1 takes in outside air through the air cleaner 4 and the intake passage 2. At the same time as the intake of the outside air, fuel is injected from the injectors 5A to 5D to the vicinity of the intake manifold 2a, so that the mixture of the fuel and the outside air is taken into the combustion chamber of each cylinder. Then, the taken-in air-fuel mixture explodes and burns in each combustion chamber due to the operation of the ignition plugs 6A to 6D, so that a piston, a crankshaft, and the like (not shown) operate to drive the engine 1.
That is, the engine output is obtained. Further, the burned gas after being burnt in each combustion chamber is guided to the exhaust passage 3 as exhaust gas, purified by the catalytic converter 7, and then discharged to the outside.

As shown in FIGS. 3 and 4, in the middle of the intake passage 2, a linkless type sub-throttle valve 8 and a link type main throttle valve 9 are arranged in series from the upstream side thereof. The main throttle valve 9 is mechanically connected to an accelerator pedal 10 provided in the driver's seat by an accelerator link.
It is opened and closed in conjunction with the operation of. The main throttle valve 9 is always biased in the closing direction by a return spring (not shown). As shown in FIG. 5, in this embodiment, the opening of the main throttle valve 9, that is, the main throttle opening TAM, is a linear opening characteristic unique to the operation amount of the accelerator pedal 10, that is, the accelerator opening ACCP. Is set to have. On the other hand, the sub-throttle valve 8 constitutes an output adjusting means in this embodiment, and is opened / closed by the operation of a step motor 11 as an output adjusting driving means provided in the vicinity thereof.
The support shaft of the sub-throttle valve 8 is connected to the output shaft of the step motor 11. The sub-throttle valve 8 is always urged in the opening direction by a return spring (not shown). As shown in FIG. 5, in this embodiment,
The opening of the sub throttle valve 8, that is, the sub throttle opening T
AS is set with two types of non-linear opening characteristics (for high μ road and low μ road) with respect to accelerator opening ACCP. Each of these nonlinear opening characteristics is selectively used according to various operating conditions. Here, the non-linear opening characteristic for high μ roads is selectively used to improve the accelerator controllability during normal running of the vehicle on a slippery road surface. Further, the non-linear opening characteristic for low μ roads is selectively used to realize good accelerator controllability even on slippery road surfaces.
Then, by opening and closing the main throttle valve 9 and the sub-throttle valve 8 with the respective opening characteristics as described above, the intake air amount Q taken into each cylinder through the intake passage 2
Is adjusted to control the engine output.

In this embodiment, the accelerator pedal 10 is operated under various driving conditions in order to improve the operability of the vehicle.
The engine output corresponding to the manipulated variable is optimally set by the cooperation of the opening characteristics of both throttle valves 8 and 9 as described above. That is, the sub-throttle valve 8 is controlled in the closing direction by the step motor 11 while the engine 1 is operating, so that the intake air amount Q that is uniquely adjusted by the main throttle valve 9 that is interlocked with the accelerator pedal 10 is further reduced. . As a result, the engine output is suppressed, the engine output characteristic for the operation of the accelerator pedal 10 is appropriately set under various operating conditions, and good accelerator controllability is realized over the entire operating range. Furthermore,
In this embodiment, since it is a two-valve type throttle,
Even if the sub-throttle valve 8 fails (fails), the driver returns the accelerator pedal 10,
The main throttle valve 9 is closed and the engine 1 can be decelerated without delay. When the sub-throttle valve 8 fails at the fully open position, the driver arbitrarily operates the accelerator pedal 10 to open the main throttle valve 9 and control the engine output arbitrarily. Is. As a result, the vehicle can be evacuated when the vehicle fails.

As a sensor for detecting various operating states of the vehicle and the engine 1, in the vicinity of the main throttle valve 9,
A main throttle sensor 31 for detecting the main throttle opening TAM is provided. A sub throttle sensor 32 for detecting the sub throttle opening TAS is provided near the sub throttle valve 8. Further, an accelerator sensor 33 for detecting the accelerator opening degree ACCP is provided near the accelerator pedal 10. In addition, in the intake passage 2, an intake pressure sensor 34 for detecting the intake pipe negative pressure PiM is provided downstream of both throttle valves 8 and 9. In addition, an oxygen sensor 35 for detecting the oxygen concentration Ox in the exhaust, that is, the exhaust air-fuel ratio in the exhaust passage 3 is provided in the middle of the exhaust passage 3. Further, the engine 1 is provided with a water temperature sensor 36 for detecting the temperature of the cooling water, that is, the cooling water temperature THW.

The ignition signal distributed by the distributor 12 is applied to the ignition plugs 6A to 6D provided in each cylinder of the engine 1. The distributor 12 is for distributing the high voltage output from the igniter 13 to each ignition plug 6A-6D in synchronization with the crank angle of the engine 1. The ignition timing of each of the spark plugs 6A to 6D is determined by the high voltage output timing from the igniter 13.

The distributor 12 is provided with a rotation speed sensor 37 for detecting the rotation speed NE (engine rotation speed) NE of the engine 1 from the rotation of a rotor (not shown). Further, the distributor 12 is provided with a cylinder discrimination sensor 38 for detecting a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor. In this embodiment, it is assumed that the crankshaft makes two revolutions for a series of strokes (intake stroke, compression stroke, expansion stroke, exhaust stroke) in the engine 1, and the cylinder discrimination sensor 38 determines the crank angle at a rate of 360 ° CA. To detect.

In this embodiment, a pair of left and right drive wheels 14L and 14R are provided on the rear side of the vehicle, and a pair of left and right driven wheels 15L and 15R are provided on the front side of the vehicle. Both drive wheels 14L and 14R are rotationally driven by the driving force from the engine 1. Therefore, the transmission 16 is drivingly connected to the crankshaft of the engine 1, and the transmission 16 includes the propeller shaft 17, the differential gear 18, and the pair of left and right drive shafts 19L and 19R.
The driving wheels 14L and 14R on the left and right sides are drivingly connected to each other. On the other hand, the driven wheels 15L and 15R rotate together with the traveling of the vehicle, and are also steering wheels that are operated by operating a steering wheel (not shown) to steer the vehicle.

In this embodiment, the left and right drive wheels 14
L and 14R are provided with drive wheel speed sensors 39L and 39R for detecting their rotational speeds, that is, the left drive wheel rotational speed VWNRL and the right drive wheel rotational speed VWNRR, respectively. The left and right driven wheels 15L and 15R have their rotational speeds, that is, the left driven wheel rotational speed VWNF.
L and driven wheel speed sensors 40L and 40R for detecting the right driven wheel rotation speed VWNFR are respectively provided. These speed sensors 39L, 39R, 40L, 40
Each R is composed of a gear 20 and a pickup coil 21.

Further, in this embodiment, the transmission 16 is provided with a vehicle speed sensor 41 for detecting the vehicle speed (vehicle speed) SPD. This vehicle speed sensor 41 is a transmission 1
This is a system in which a reed switch is driven by a magnet that is rotated by rotation of a gear No. 6 and outputs a pulse signal corresponding to the vehicle speed SPD.

Further, the transmission 16 is set to 1 by shifting the shift lever 22 provided in the driver's seat.
It is possible to shift to each shift speed of 2nd speed, 3rd speed, 4th speed, 5th speed and 6th speed, and also to shift for neutral and reverse (in particular, in the case of a manual transmission in this embodiment). I will explain mainly). Then, in the vicinity of the shift lever 22, each shift speed and each shift position of neutral and reverse are detected and output as a shift position signal SPS (for example, in the case of the first speed, the shift position signal SPS is "1"). A shift position sensor 42 is mounted.

The rotation speed sensor 37, the cylinder discrimination sensor 38, the speed sensors 39L, 39R, 40L, 40R,
The vehicle speed sensor 41 and the shift position sensor 42 also constitute sensors that detect various driving states.

Further, as shown in FIG. 6, in this embodiment, the instrument panel 2 in front of the driver's seat of the vehicle is used.
3 is provided with a slip control off switch 43. The switch 43 is operated so that the driver can arbitrarily prohibit the operation of a slip control described later. That is, the operation of the slip control is prohibited when the switch 43 is pressed only once. Further, when the switch 43 is pressed again from this prohibition state, the operation of the slip control is permitted.

In addition, in the meter 24 having the instrument panel 23, two types of indicators 44 and 45 are provided.
Is provided. One of them is a slip control off indicator 44, and the other is a slip control operation indicator 45. The slip control off indicator 44 is turned on when the slip control off switch 43 is pressed only once (operation of the slip control is prohibited), and the switch 43 is pressed once more (operation of the slip control is activated). Is allowed), it goes out. Further, the indicator 44 is designed to blink when an abnormality such as a sensor failure occurs.

Further, the slip control operation indicator 45 is turned off, turned on or blinked depending on the control contents of the slip control. More specifically, the road friction coefficient should be estimated and the high μ road nonlinear control should be performed. When it is determined that the road is a high μ road, it is determined that the control for slip control is not performed, and the slip control operation indicator 45 is turned off. To be done. The operation indicator 45 blinks while the slip amount exceeds the predetermined amount and the slip suppression control is being executed. Further, when the slip cannot be suppressed even further, that is, when it is determined that the low μ road should be subjected to the low μ road nonlinear control, the operation indicator 45 is turned on. Therefore, the driver
Regarding the slip control, one of the above-mentioned three controls can be recognized by one slip control operation indicator 45 at present. In addition, the driver uses one lip control off indicator 44 to indicate whether slip control is activated, deactivated, or abnormal.
Can recognize two states. Therefore, the slip control control state can be sufficiently recognized without adding many indicators in the meter 24.

In this embodiment, a main throttle sensor 31, a sub throttle sensor 32, an accelerator sensor 33, an intake pressure sensor 34, an oxygen sensor 35, a water temperature sensor 35, a rotation speed sensor 37, a cylinder discrimination sensor 38, a vehicle speed sensor 41 and a shift. The position sensor 42 is connected to an engine electronic control unit (hereinafter referred to as “engine ECU”) 51. Further, the injectors 5A to 5D and the igniter 13 are connected to the engine ECU 51, respectively. The engine ECU 51 uses various sensors 31 to 31.
Based on various signals input from 38, 41, 42, the operations of the injectors 5A to 5D, the igniter 13 and the like are suitably controlled in order to execute the fuel injection amount control and the ignition timing control of the engine 1. In addition, the engine ECU 51
Is the sub throttle valve 8 based on various input signals.
Performs a fail-safe operation required when failing.

While the engine ECU 51 is a device that controls fuel injection amount control and ignition timing control, in this embodiment, a throttle electronic control device (hereinafter "throttle ECU") that controls the opening and closing of the sub-throttle valve 8 is used. 52) is provided. This throttle ECU 5
2 is connected to the engine ECU 51, and both 51,
Signals are exchanged between 52. In addition, the throttle ECU 52 includes drive wheel speed sensors 39L, 39R,
The driven wheel speed sensors 40L and 40R and the slip control off switch 43 are connected. In addition, the throttle ECU 52 is connected with the slip control off indicator 44, the slip control operation indicator 45, and the step motor 11. Of the various signals input to the engine ECU 51,
Various signals such as a main throttle opening TAM, a sub-throttle opening TAS, an accelerator opening ACCP, an engine speed NE, a vehicle speed SPD, a shift position signal SPS and the like necessary for controlling the opening and closing of the sub-throttle valve 8 are output to the engine ECU 51.
Is input to the throttle ECU 52. Further, the throttle ECU 52 includes the speed sensors 39L, 39R, 40
The left drive wheel rotation speed VWNRL, the right drive wheel rotation speed VWNRR, the left driven wheel rotation speed VWNFL, and the right driven wheel rotation speed VWNFR and the on / off signal of the slip control off switch 43 are input from L and 40R. Then, the throttle ECU 52 suitably controls the step motor 11 to control the sub-throttle valve 8 according to the operating state of the engine 1, that is, the sub-throttle control based on various input signals. Further, the throttle ECU 52 preferably controls the slip control off indicator 44 and the slip control operation indicator 45 according to the control content.

FIG. 7 is a block diagram showing the electrical construction of the engine ECU 51 and the throttle ECU 52. The engine ECU 51 includes a central processing unit (CPU) 53 that also has a counter function, a read-only memory (ROM) 54 that stores a predetermined control program and the like in advance, and a CPU 5
Random access memory (RAM) 55 for temporarily storing the calculation result of 3 and the like, backup RAM 56 for storing previously stored data, and the like. The engine ECU 51 is configured as a logical operation circuit in which these units 53 to 56, the external input / output circuit 57, and the like are connected by a bus 58. The external input / output circuit 57 includes a main throttle sensor 31, a sub throttle sensor 32, an accelerator sensor 33, an intake pressure sensor 34, an oxygen sensor 35,
Water temperature sensor 36, rotation speed sensor 37, cylinder discrimination sensor 3
8, a vehicle speed sensor 41 and a shift position sensor 42 are connected to each other. Further, the injectors 5A to 5D and the igniter 13 are connected to the external input / output circuit 57. In addition, the above-mentioned throttle ECU 52 is connected to the external input / output circuit 57.

The CPU 53 has an external input / output circuit 57.
Various signals input from the respective sensors 31 to 38, 41, 42 via the are read as input values. The CPU 53 executes fuel injection amount control, ignition timing control, etc. based on the control program stored in the ROM 54 based on the input values. Further, the CPU 53 is a ROM based on the input value.
A fail-safe operation is executed based on the control program stored in 54. Further, among various signals input via the external input / output circuit 57, various signals required for sub-throttle control are output to the throttle ECU 52.

On the other hand, the throttle ECU 52 is the engine E.
It has basically the same configuration as the CU51, and has a CPU 6
1, ROM 62, RAM 63, backup RAM 6
4, an external input / output circuit 65, a bus 66 and the like. The drive wheel speed sensors 39L and 39R, the driven wheel speed sensors 40L and 40R, and the slip control off switch 43 are connected to the external input / output circuit 65, respectively. Further, the external input / output circuit 66 is connected to the slip control off indicator 44, the slip control operation indicator 45, and the step motor 11. Further, the ROM 62 stores in advance a control program and the like for sub-throttle control.

The CPU 61 is the engine ECU 51.
Also, various signals input from the speed sensors 39L, 39R, 40L, 40R and the switch 43 via the external input / output circuit 65 are read as input values. Further, the CPU 61 suitably controls the step motor 11 and both indicators 44, 45 based on the control program stored in the ROM 62 based on the input values.

Next, the processing operation for the opening / closing control of the sub-throttle valve 8 executed by the above-mentioned throttle ECU 52 will be described with reference to the flowcharts shown in FIGS. In this embodiment, the opening / closing control of the sub-throttle valve 8 when performing the slip suppression control will be mainly described.

By the way, the flow chart shown in FIG.
The "slip suppression flag and fail flag setting routine" for setting the slip suppression flag XDLTAV and the fail flag XFAIL, which is executed by the throttle ECU 52, is shown. This routine is executed by a regular interrupt every predetermined time, for example, "32 ms".

Further, the flow chart shown in FIG. 9 shows the sub-throttle valve 8 executed by the throttle ECU 52.
Throttle opening final required value TTA02 which is the target opening of
The "throttle opening final required value setting routine" for setting is shown. This routine is executed every predetermined time, for example, "96 ms".

Now, when the processing shifts to the "slip suppression flag and fail flag setting routine" shown in FIG.
First, in step 101, the drive wheel speed sensor 39
Left and right drive wheel rotation speeds VNRRL, V by L, 39R
While reading RNRR, driven wheel speed sensor 40
Left and right driven wheel rotation speeds VWNFL, V by L, 40R
Read WNFR. Further, the on / off signal of the slip control off switch 43 is read.

Next, in step 102, the drive wheel average rotation speed VWNRM, which is the average value of the left and right drive wheel rotation speeds VRNRL and VRNRR, is calculated. Similarly, the left and right driven wheels rotating speed VWNFL,
Based on VWNFR, average driven speed VWNFM of both wheels is calculated.

Subsequently, at step 103, it is determined whether or not the left and right driving wheel speed sensors 39L and 39R and the left and right driven wheel speed sensors 40L and 40R have a failure. The condition for this determination is, for example, “when the larger value of the left and right driven wheel rotation speeds VWNFL and VWNFR is 11 km / h or more, the rotation speed of a certain wheel (any wheel may be 0 km / h). Whether it is h ”
Etc. When this determination condition is satisfied, the speed sensors 39L, 39R, 40 are broken due to disconnection, short circuit, or the like.
It is estimated that at least one of L and 40R is out of order. Then, the process proceeds to step 104, and the fail flag XFAIL is set to "1".

In the following step 105, the slip control off indicator 44 blinks. Then, in the next step 106, the slip suppression flag XDLTAV is set to "0". Finally, step 1
Slip control operation indicator 4 at 07
5 is turned on or off, and the subsequent processing is temporarily terminated.
Here, the slip control operation indicator 45
Is turned off when at least one of the speed sensors 39L, 39R, 40L, 40R is out of order or when the high μ road nonlinear control (see the second embodiment) is performed. Further, when the low μ road non-linear control (see the second embodiment) is performed, the slip control operation indicator 45 is turned on.

On the other hand, if it is determined in step 103 that the left and right driving wheel speed sensors 39L and 39R and the left and right driven wheel speed sensors 40L and 40R have not failed, the routine proceeds to step 108. In step 108,
The fail flag XFAIL is set to "0".

In the following step 109, it is judged whether or not the slip control off switch 43 is in the on state based on the on / off signal read this time. Then, when the slip control off switch 43 is in the on state, it is determined that the slip suppression control is prohibited by the driver, and the process proceeds to step 118,
The slip control off indicator 44 is turned on. Then, the processing of step 106 and step 107 is executed, and the subsequent processing is once ended.

If the slip control off switch 43 is in the off state in step 109, it is determined that the slip suppression control is not prohibited by the driver, and the process proceeds to step 110. Step 1
At 10, the slip control off indicator 44 is turned off.

Next, at step 111, the drive wheel average rotation speed VWNRM and the driven wheel average rotation speed VWNF.
It is determined whether the deviation from M is larger than the predetermined speed a. Deviation of this rotation speed (VWNRM-VWNFM)
Corresponds to the slip amount of the drive wheels 14L and 14R. In this step 111, not only the slip amount but also the slip ratio may be taken into consideration. For example, it may be considered whether or not the deviation of the rotation speed (VWNRM-VWNFM) is larger than a value obtained by multiplying the average driven speed of the driven wheels VWNFM by a predetermined rate. Then, when the deviation of the rotation speed (VWNRM-VWNFM) is larger than the predetermined speed a, it is determined that the slip suppression control needs to be performed, and the processes of step 112 and step 113 are executed. That is, in step 112, the step suppression flag XDLTAV is set to "1". Also,
In step 113, the slip control operation indicator 45 is blinked. Then, the process proceeds to the next step 114. Further, in step 111, the deviation of the rotation speed (VWNRM-VWNFM) is the predetermined speed a.
In the following cases, it is determined that it is not necessary to perform the slip suppression control, and the process of step 112 and step 113 is not executed and the process jumps to step 114.

In step 114, which is a transition from step 111 or step 113, it is determined whether or not the deviation of the rotational speed (VWNRM-VWNFM) is smaller than a predetermined speed b (smaller than the predetermined speed a). .
In step 114 as well, as in step 111, not only the slip amount but also the slip ratio may be taken into consideration. Then, the deviation of the rotation speed (VWNRM-VW
If NFM) is not smaller than the predetermined speed b, the count value of the slip suppression counter CDLTA is cleared to "0", and the subsequent processing is temporarily terminated. When the deviation of the rotation speed (VWNRM-VWNFM) is smaller than the predetermined speed b, the routine proceeds to step 116, where the count value of the slip suppression counter CDLTA is incremented. In this case, "32 ms" is added.

Then, in step 117, the count value of the slip suppression counter CDLTA is "1.0 s".
ec ”is exceeded. Then, when the count value does not exceed "1.0 sec",
The subsequent processing is once ended. When the count value exceeds "1.0 sec", it is determined that it is not necessary to perform the slip suppression control, the process proceeds to step 106, and the slip suppression flag XDLTAV is set to "0". Then, in step 107, the slip control operation indicator 45 is turned on or off, and the subsequent processing is temporarily terminated.

As described above, in the "slip suppression flag and fail flag setting routine", the slip suppression flag XDLTAV and the fail are determined based on the deviation (VWNRM-VWNFM) of the rotational speed and the ON / OFF signal of the switch 43 at that time. The flag XFAIL is set. Also, depending on the setting contents, both indicators 4
4, 45 are controlled to be turned on, turned off or blinking.

Next, the set slip suppression flag XD is set.
The processing operation for setting the throttle opening final required value TTA02 based on LTAV and the fail flag XFAIL will be described. When the processing shifts to the "throttle opening final required value setting routine" shown in FIG. 9, first,
In step 201, it is determined whether or not the fail flag XFAIL is "0". Then, when the fail flag XFAIL is "0", it is determined in step 202 whether the slip suppression flag XDLTAV is "0". When the slip suppression flag XDLTAV is not "0", the speed sensors 39L, 39R,
It is assumed that 40L and 40R have not failed and that slip suppression control needs to be performed, and the process proceeds to step 203. Then, in step 203, slip suppression control is executed.

The slip suppression control is a technique proposed by the applicant of the present application in Japanese Patent Application No. 3-294650. That is, in a state in which the driving force is transmitted to both the drive wheels 14L and 14R after the engine 1 is started, the actual rotational acceleration of the drive wheels 14L and 14R is the target drive obtained by using the accelerator opening ACCP as one parameter. The step motor 11 is driven so as to achieve wheel rotation acceleration. By performing this control, the opening / closing control of the sub-throttle valve 8 is performed and the output control of the engine 1 is performed.

Therefore, the rotational accelerations of the drive wheels 14L and 14R are always adjusted according to the acceleration operation amount of the accelerator pedal 10. As a result, even when a slip occurs, the driver can intentionally control the rotational accelerations and rotational speeds of the drive wheels 14L and 14R, thereby realizing a highly responsive driving without a feeling of rattling or discomfort. It becomes possible.

If the slip suppression flag XDLTAV is "0" in step 202, the speed sensors 39L, 39R, 40L, 40R have not failed and the slip suppression control need not be performed. Assuming that the control is completed, the process proceeds to step 204. In step 204, a value obtained by adding "c °" to the throttle opening final required value TTA02 in the previous routine is set as the throttle opening final required value TTA02.

On the other hand, when the fail flag XFAIL is not "0" at the step 201, at least one of the speed sensors 39L, 39R, 40L and 40R is set.
Assuming that one of them has failed, the process proceeds to step 205. In step 205, the throttle opening final required value TTA02 in the previous routine is set to "d ° (where d <
c) ”is added to the throttle opening final required value TTA
Set as 02.

Then, steps 205, 203 and 204
Then, in step 206, it is determined whether or not the set throttle opening final required value TTA02 is “e °” or more. Then, when the final required throttle opening value TTA02 is not equal to or greater than "e °", the subsequent processing is temporarily terminated.

Further, the throttle opening final required value TTA0
When 2 is equal to or larger than "e °", the final throttle opening required value TTA02 is set to "e °" uniformly, and the subsequent processing is temporarily terminated. Then, the step motor 11 is drive-controlled so that the sub throttle opening TAS matches the throttle opening final required value TTA02. Thus, this "throttle opening final required value setting routine"
In, the throttle opening final required value TTA02 is set according to the fail flag XFAIL and the slip suppression flag XDLTAV. That is, when the speed sensors 39L, 39R, 40L, 40R are not out of order and the slip suppression control needs to be executed, the slip suppression control is executed (step 203). Further, as shown in FIG. 10, each speed sensor 39L, 39R, 40
When the L and 40R are not broken and the slip suppression control is completed, the sub throttle valve 8 is opened at a relatively high speed of "c ° / 96 ms" (broken line in FIG. 10). Furthermore, each speed sensor 39L, 39R, 40L,
If one of the 40Rs fails, "d ° / 96
The sub throttle valve 8 is opened at a relatively slow speed of "ms" (solid line in FIG. 10).

As described above, since it is possible to detect that there is no slip during normal operation, there is no problem because slip suppression control is executed even if slip occurs if the sub-throttle valve 8 is opened at a high speed. Also, the speed sensor 3
When 9L, 39R, 40L, 40R fails, it is desired to end the slip suppression control so as not to sacrifice the acceleration performance, but the slip state cannot be detected, which makes control difficult. Therefore, by slowly opening the sub-throttle valve 8, it is possible to prevent slippage and prevent output reduction, and it is possible to ensure excellent drivability at the time of failure.

Further, in this embodiment, the driving speed of the step motor 11 when the sub-throttle valve 8 is opened at the time of failure is slower than the driving speed of the motor 11 at the normal time. Therefore, it is possible to reliably prevent a sudden change in the output of the engine 1 when a failure occurs. As a result, each speed sensor 39L, 39R, 40
Even if one of L and 40R fails, it is possible to reliably prevent deterioration of drivability due to a sudden change in output.

Further, in this embodiment, since the slip control off switch 43 is provided,
The driver can arbitrarily prohibit the slip suppression control. In addition, in this embodiment, a slip control off indicator 44 and a slip control operation indicator 45 are provided. Therefore, when the slip control off switch 43 is turned on, the slip control off indicator 44 is turned on. Therefore, the driver can easily recognize the current operating state of the switch 43. The slip control operation indicator 45 is turned off, turned on, or blinked depending on the control content of the slip control. Therefore, the driver can easily recognize what kind of control is currently being performed regarding the slip control by means of the indicator 45.

(Second Embodiment) Next, a second embodiment embodying an output control device for an internal combustion engine according to the present invention will be described with reference to FIG.
~ It demonstrates based on FIG. The basic structure of the device in the second embodiment is almost the same as that in the first embodiment. Therefore, in the second embodiment, differences from the first embodiment will be described below.

In this embodiment, the throttle EC
Two types of maps are stored in advance in the ROM 62 of the U52. These maps show the main throttle opening TA
The characteristics of the target opening value of the sub-throttle valve 8 with respect to M (corresponding to the accelerator opening ACCP) are defined. One characteristic is a non-linear opening characteristic for a high μ road for obtaining a relatively large engine output in order to improve the accelerator controllability on a slippery road surface. The other characteristic is a non-linear opening degree characteristic for a low μ road for suppressing the engine output so as to realize a good accelerator controllability even on a slippery road surface.

The throttle ECU 52 (CPU 61)
Based on the running state of the vehicle and the operating state of the engine 1 at that time, two types of maps (non-linear opening characteristic for high μ road and non-linear opening characteristic for low μ road) stored in the ROM 62 are stored. Select one. Further, based on the characteristics of the selected map, the target opening values of the sub-throttle valve 8 corresponding to the main throttle opening TAM (throttle opening required value TTAH for high μ road, throttle opening required value TTA for low μ road).
L) is calculated. Then, the calculated required opening value is set to the target opening of the sub-throttle valve 8 (throttle opening final required value TTA
01), and the drive of the step motor 11 is controlled so that the opening of the sub-throttle valve 8 (sub-throttle opening TAS) matches that value.

Further, when the throttle ECU 52 is executing control according to one characteristic and selects the other characteristic, the throttle opening request values TTAH and TTAL obtained from two types of maps are interpolated and the throttle opening request values TTAH and TTAL are calculated. The calculated value (correction value) is used as the throttle opening final required value TTA.
01.

Next, the processing operation for the opening / closing control of the sub-throttle valve 8 executed by the throttle ECU 52 will be described with reference to the flowcharts shown in FIGS. In this embodiment, the sub-throttle valve 8 is mainly used when performing non-linear control for each road surface.
The open / close control will be described. The description of the slip control off switch 43 described in the first embodiment will be omitted for convenience.

By the way, the flowchart shown in FIG. 12 shows that the throttle opening final required value T, which is the target opening of the sub-throttle valve 8 executed by the throttle ECU 52.
The "throttle opening final required value setting routine" for setting TA01 is shown. This routine is executed every predetermined time, for example, every "8 ms".

The flowchart shown in FIG. 13 shows a "μ road determination routine" for setting the road surface μ determination flag XMUE among the processes executed by the throttle ECU 52. This routine is executed every predetermined time, for example, every "32 ms". Road μ judgment flag X
The MUE is for determining whether or not the road surface is slippery, and its initial value is "0". The road surface μ determination flag XMUE is basically set to “1” when the road surface is a low μ road and reset to “0” when the road surface is a high μ road. Further, the processing of the “μ road determination routine” is executed based on the high μ road determination counter CHIMUE. High μ road determination counter CHIMU
E is for determining the high μ road when the count value is “1.0 sec” or more.

In addition, the flow chart shown in FIG.
The "count value setting routine" for setting the count value of the road surface μ transition counter CMUETRN is shown. This count value setting routine is executed every predetermined time, for example, every 32 ms. The count value of the road surface μ transition counter CMUETRN takes a value between “0 and 1.0” and is set based on the road surface μ determination flag XMUE. In addition, this count value is the throttle opening final required value TTA01.
It has a great influence on the setting of.

Now, when the processing shifts to the "throttle opening final required value setting routine" shown in FIG. 12, first, at step 301, the throttle opening required value for each road surface set by a separate routine, that is, the high throttle opening required value is set. The throttle opening request value TTAH for μ road and the throttle opening request value TTAL for low μ road are read.

Subsequently, at step 302, a road surface μ transition counter CM set by a separate routine is set.
Read the count value of UETRN. Then, in step 303, the throttle opening request value TTAH for the high μ road, the throttle opening request value TTAL for the low μ road, and the road μ transition counter CMUET read in this routine.
A throttle opening final required value TTA01 is set based on the count value of RN. That is, the high μ road throttle opening request value TTAH is set to the road μ transition counter CMUETR.
The value obtained by multiplying the count value of N and "1.0"
A sum of a value obtained by subtracting the count value of the transition counter CMUETRN and a value obtained by multiplying the low μ road throttle opening request value TTAL is set as the throttle opening final request value TTA01 (see the following calculation formula (1)). Then, the subsequent processing is temporarily terminated.

TTA01 = CMUETRN * TTAH + (1.0-CMUETRN) * TTAL (1) Then, the step motor 11 is drive-controlled so that the sub-throttle opening TAS matches the throttle opening final required value TTA01. .

As described above, the throttle opening request value TTAH for the high μ road and the throttle opening request value TTAL for the low μ road are two types of maps corresponding to the main throttle opening TAM and the engine NE. Is set in a separate routine. However, description of the processing operation is omitted here.

Further, the road surface μ transition counter CMUETRN
Is also set in a separate routine. Next, a process for setting the road surface μ determination flag XMUE used when setting the count value of the road surface μ transition counter CMUETRN will be described. When the processing shifts to the “μ road determination routine” shown in FIG. 13, first, at step 401, the left and right driving wheel rotation speeds VNRRL and VNRRR are read by the driving wheel speed sensors 39L and 39R, and the driven wheel speed sensors 40L and 40R are read. The left and right driven wheel rotational speeds VWNFL and VWNFR are read. Further, the main throttle opening degree TAM from the main throttle sensor 31 and the shift position signal SPS from the shift position sensor 42 are read.

Next, in step 402, the drive wheel average rotation speed VWNRM, which is the average value of the left and right drive wheel rotation speeds VNRRL and VRNRR, is calculated. Similarly, the left and right driven wheels rotating speed VWNFL,
Based on VWNFR, average driven speed VWNFM of both wheels is calculated.

Subsequently, in step 403, the drive wheel average rotation speed VWNRM is set to a predetermined speed f.
It is determined whether or not the above, and in step 104,
Driving wheel average rotation speed VWNR and driven wheel average rotation speed V
It is determined whether or not the deviation from WNFM is less than a predetermined speed g. This rotation speed deviation (VWNRM-VWNF
M) corresponds to the slip amount of the drive wheels 14L and 14R. In this step 403, not only the slip amount but also the slip ratio may be taken into consideration as described in the first embodiment.

When both the judgment conditions of steps 403 and 404 are satisfied (VWNRRM ≧ f, and
(VWNRM-VWNFM) <g), the process proceeds to step 405. On the other hand, if both the determination conditions of steps 403 and 404 are not satisfied (VWNRM <f and / or (VWNRM <f
WNRM-VWNFM) ≧ g), the process proceeds to step 407.

In step 405, the high μ road determination throttle opening KTAM is calculated. That is, the ROM 62
The high μ road determination throttle opening degree KTAM is stored in advance in each gear stage of the transmission 16. In this embodiment, as the shift speed becomes higher, the high μ road determination throttle opening K
The TAM is set to a large value. Then, the high μ road determination throttle opening KTAM corresponding to the shift position signal SPS at that time is obtained.

Next, at step 406, the main throttle opening TAM at step 401 is set to the high μ.
It is determined whether or not the road determination throttle opening is less than KTAM. When the determination condition in step 406 is satisfied (TAM <KTAM), or the above step 4
If either of the judgment conditions 03, 404 is not satisfied (VWNRM <f and / or (VWNR
For M-VWNFM) ≧ g), it is determined that there is a high possibility that the vehicle is traveling on a low μ road having a low road friction coefficient μ and the drive wheels 14L and 14R are slipping. And step 4
At 07, the count value of the high μ road determination counter CHIMUE is cleared to "0".

On the other hand, when the determination condition of step 406 is not satisfied (TAM ≧ KTAM), the vehicle is traveling on a slippery high μ road having a high road surface friction coefficient μ and the drive wheels 14
It is determined that there is a high possibility that L and 14R are gripping the road surface, and the count value of the high μ road determination counter CHIMUE is incremented. In this case, "32 ms" is added.

Step 407 or Step 40
In step 409 after shifting from 8, it is determined whether or not the left and right driving wheel speed sensors 39L and 39R and the left and right driven wheel speed sensors 40L and 40R have a failure. When this determination condition is satisfied, it is estimated that at least one of the speed sensors 39L, 39R, 40L, 40R has failed due to a disconnection, a short circuit, or the like.

If the determination condition in step 409 is not satisfied, it is determined in step 410 whether or not the road surface μ determination flag XMUE in the previous control cycle is "1". When the determination condition in step 410 is not satisfied (XMUE = "0"), that is, when the high μ road determination is performed in the previous control cycle, the process proceeds to step 411. In step 411, it is determined whether or not the deviation (slip amount) between the drive wheel average rotation speed VWNRM and the driven wheel average rotation speed VWNFM is equal to or greater than a predetermined speed h. When the determination condition of step 411 is satisfied ((VWNRM-VWNFM) ≧ h), the road surface has a low μ.
Judge as the road. Then, in step 412, the road surface μ determination flag XMUE is set to “1”. Further, in step 413, the slip control operation indicator 45 is turned on, and the subsequent routine is once ended. On the other hand, when the determination condition of step 411 is not satisfied ((VWNRM-VWNFM) <
In h), it is determined that the road surface is a high μ road, and the subsequent routine is once ended. Therefore, in this case, the road surface μ determination flag XMUE is held at “0”.

On the other hand, if the determination condition in step 410 is satisfied (XMUE = 1), that is, if the low μ road determination is made in the previous control cycle, step 4
Move to 14. In step 414, it is determined whether or not the count value of the high μ road determination counter CHIMUE in step 408 is equal to or longer than the predetermined time i. When the determination condition of step 414 is not satisfied (CH
For IMUE <i), it is determined that the road surface is a low μ road, and the subsequent processing is temporarily terminated. Therefore, in this case, the road surface μ determination flag XMUE is held at “1”.

When the determination condition of step 414 is satisfied (CHIMUE ≧ i), it is determined that the road surface is a high μ road, and the road surface μ determination flag XMUE is determined in step 415.
Is set to "0". Then, in step 416, the slip control operation indicator 45 is turned off, and the subsequent routine is temporarily terminated.

By the way, when the judgment condition of the step 409 is satisfied, that is, the left and right driving wheel speed sensors 39L and 39R and the left and right driven wheel speed sensors 40L and 4 respectively.
Even if any one of 0R is out of order, the process proceeds to step 415. Then, in step 415, the road surface μ determination flag XMUE is set to "0", in step 416, the slip control operation indicator 45 is turned off, and the subsequent processing is temporarily terminated.

In this way, the drive wheel average rotational speed VW
The road surface μ determination flag XMUE is “0 (high μ road)” based on the deviation between the NRM and the average driven speed VWNFM of the driven wheels.
Alternatively, it is set to “1 (low μ road)”. Further, the slip control operation indicator 45 is turned on or off according to the road surface μ determination flag XMUE.

Next, the "count value setting routine" for setting the count value of the road surface μ transition counter CMUETRN based on the road surface μ determination flag XMUE set in the "μ road determination routine" will be described.

When the processing shifts to the "count value setting routine" shown in FIG. 14, first in step 501,
It is determined whether or not the road surface μ determination flag XMUE is “0”.
When the road surface μ determination flag XMUE is “0”, it is temporarily determined that the road surface on which the vehicle is currently traveling is a high μ road, and the process proceeds to the next step 502.

In step 502, it is determined whether the fail flag XFAIL is "0". When the fail flag XFAIL is "0", it is assumed that there is no failure in the speed sensors 39L, 39R, 40L, 40R, and the throttle opening increase ratio transition speed KTINC is set to a relatively small "64" in step 503.
ms ”. On the other hand, if the fail flag XFAIL is not "0", that is, "1", at least 1 of the speed sensors 39L, 39R, 40L, 40R is selected.
Assuming that one failure has occurred, in step 504, the throttle opening increase ratio transition speed KTINC is set to a relatively large “2048 ms”.

After shifting from step 503 or step 504, in step 505, the count value of the increase ratio shift counter TINC is incremented. In this case, in this case, "32 ms" is added.

Subsequently, in step 506, it is judged whether or not the count value of the incremented increase ratio transition counter TINC is equal to or greater than the throttle opening increase ratio transition speed KTINC set in step 503 or step 504. The increase ratio transition counter TI
When the count value of NC is still smaller than the throttle opening increase ratio transition speed KTINC, the subsequent processing is temporarily terminated.

Further, the count value of the increase ratio transition counter TINC is the throttle opening increase ratio transition speed KT.
If it is greater than or equal to INC, the process proceeds to step 507. Therefore, if there is no failure in the speed sensors 39L, 39R, 40L, 40R, the condition of step 506 is satisfied by going through the control cycle twice. On the other hand, if the speed sensor 39L, 39R, 40L, 40R has a failure, the condition of step 506 is finally satisfied by passing the control cycle 64 times.

Next, at step 507, the road surface μ
The count value of the transition counter CMUETRN is incremented. In this case, "0.005" is added. Next, at step 508, the road surface μ transition counter C
It is determined whether or not the count value of MUETRN exceeds “1.0”. Then, the road surface μ transition counter CMUETR
If the count value of N does not exceed "1.0",
Jump to step 510. That is, step 5
The value incremented in 07 is set as the count value of the road surface μ transition counter CMUETRN. Further, the count value of the road surface μ transition counter CMUETRN is “1.
If it exceeds 0 ”, the road surface μ transition counter CMUET
The count value of RN is set to "1.0", and the routine goes to the subsequent Step 510.

Then, step 508 or step 50
After shifting from 9, the count value of the increase ratio shift counter TINC is cleared to "0" in step 510, and the subsequent processing is temporarily ended. Further, when the count value of the road surface μ transition counter CMUETRN exceeds “1.0”, the count value of the road surface μ transition counter CMUETRN is set to “1.0”, and the subsequent processing is temporarily terminated.

On the other hand, when the road surface μ determination flag XMUE is not "0" in step 501, it is determined that the road surface currently running is a low μ road, and in step 511, the count value of the road surface μ transition counter CMUETRN. Is set to "0", and the subsequent processing is temporarily terminated.

Thus, the "count value setting routine"
In the above, the count value of the road surface μ transition counter CMUETRN is set in the range of “0 to 1.0”. More specifically, the count value is set to “0” when it is determined that the road surface is a low μ road. Further, the count value is set to be gradually increased when it is determined that the road surface is a high μ road, and is set to “1.0” after a lapse of a predetermined time. Furthermore, if there is a failure in the speed sensor 39L, 39R, 40L, 40R, after a considerable time has elapsed (“2
048 ms "), the count value is gradually incremented.

As described above, according to the output control device of this embodiment, when the road surface μ determination flag XMUE is not “0”, it is determined that the road surface currently running is a low μ road, The count value of the μ transition counter CMUETRN is set to “0” (step 51).
1). Therefore, when the road surface is a low μ road, the throttle opening final request value TTA01 is set to the low μ road throttle opening request value TTAL. Therefore, when traveling on a low μ road, it is possible to quickly obtain a stable output suitable for the road surface.

On the other hand, the road surface μ determination flag XMUE is "0".
If the road surface is currently running, it is determined that the road surface is currently on a high μ road, and the count value of the road surface μ transition counter CMUETRN is gradually incremented and set (step 507). Then, the road surface μ transition counter C
When the count value of MUETRN becomes larger than "1.0", the count value is uniformly set to "1.0". Therefore, when traveling from the low μ road to the high μ road, the throttle opening final required value TTA
Since 01 is gradually increased, the sudden increase in the output of the engine 1 is suppressed. Therefore, it is possible to prevent the sudden acceleration of the vehicle, the sudden increase of the slip associated therewith, and the occurrence of the vibration due to the rapid increase of the output. Further, as shown in FIG. 15, the throttle opening final required value TTA01 linearly increases, and as a result, the sub-throttle opening TAS is linearly interpolated. Therefore, the output of the engine 1 is
Immediately after the characteristic change, it will change promptly,
Good responsiveness is obtained. More specifically, when changing from a low output characteristic to a high output characteristic, the output (torque) increases rapidly and evenly. Furthermore, the increase rate of the output is higher immediately after the switching is started, and the increase rate decreases with the passage of time (see FIG. 15). Therefore, the driver can immediately experience an increase in torque immediately after the start of the switching, and as a result, can experience good drivability.

Also, in this embodiment, the speed sensor 39
When there is a failure in L, 39R, 40L, 40R (XF
When AIL = 1), after a considerable time has passed (“2048 ms”), the road surface μ transition counter CMUE
The count value of TRN is gradually incremented. Therefore, in the event of a failure, the sub throttle valve 8
As a result, the driving speed of the stepping motor 11 when the motor is opened is slower than the driving speed of the motor 11 at the normal time. Therefore, similar to the first embodiment,
It is possible to reliably suppress a sudden change in the output of the engine 1 when a failure occurs. As a result, even if one of the speed sensors 39L, 39R, 40L, 40R fails, it is possible to reliably prevent deterioration of drivability due to a sudden change in output. Further, similarly to the first embodiment, each speed sensor 39L, 39R, 40L, 40
Even if one of the Rs fails, the sub-throttle valve 8 is controlled to open. Therefore, in this case, the output of the engine 1 does not decrease, but on the contrary, the output increases. As a result, it is possible to reliably obtain the power performance required by the driver without causing acceleration failure even at the time of failure.

The present invention is not limited to the above-described embodiment, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In each of the above embodiments, the sub-throttle valve 8 is used as the output adjusting means, but in the case of the one-valve type, it may be applied to the control of the (main) throttle valve driven by the actuator. Good. Further, the present invention may be embodied in controlling the fuel injection amount of a fuel injection pump in a diesel engine as long as the output of the internal combustion engine can be controlled. At the same time, it can be applied to output control of electric vehicles and the like.

(2) In the first embodiment, the speed sensor 3
At the time of failure of 9L, 39R, 40L, 40R, the step motor 11 is controlled so that the throttle opening final required value TTA01 is increased, that is, the high output characteristic is obtained, but only in the first invention. In view of the above, it can be embodied in the opposite case, that is, in the case of controlling so as to obtain a low output characteristic. More specifically, as shown in FIG. 11, when the final throttle opening required value is minimized at the end of control, as in constant speed traveling (auto drive) control, the degree of decrease in the output of the engine 1 is made slow. Good as a thing. With such control, it is possible to prevent the rapid deceleration of the vehicle.

(3) In each of the above embodiments, the speed sensor 39
Although it has been embodied in the case of failure of L, 39R, 40L, 40R, it can be embodied in the case of failure of other sensors.

[0099]

As described in detail above, according to the first aspect of the invention, a plurality of preset control patterns of the internal combustion engine are selectively used based on the detection result of the vehicle running state detecting means.
In the output control device of the internal combustion engine, which is configured to obtain the control characteristics based on the control pattern, when a failure is detected by the failure detection unit, a predetermined control pattern is selected, and a control pattern at the time of failure is set. The change speed of the output adjustment drive means when changing from the state in which the output adjustment drive means is drive-controlled by different control patterns to the state in which the output adjustment drive means is drive-controlled by the control pattern at the time of failure I tried to make it smaller than the speed. Therefore, even if the vehicle traveling state detecting means fails, it is possible to prevent the drivability from being deteriorated due to the sudden change in the output. In addition, it is possible to prevent deterioration of vehicle behavior due to a sudden increase in slip.

According to the second aspect of the invention, the control pattern having the largest characteristic of the output of the internal combustion engine is selected from the plurality of control patterns when the failure of the vehicle running state detecting means is detected. I chose Therefore, even if the vehicle traveling state detecting means fails, it is possible to ensure the power performance that meets the driver's demand.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram showing a basic conceptual configuration of a first invention.

FIG. 2 is a conceptual configuration diagram showing a basic conceptual configuration of a second invention.

FIG. 3 is a schematic configuration diagram showing a schematic configuration of an output control device for an internal combustion engine in a first embodiment embodying the first and second inventions.

FIG. 4 is a schematic cross-sectional view showing an arrangement state and the like of both throttle valves in the middle of the intake passage in the first embodiment.

FIG. 5 is a graph showing the relationship between the main throttle opening and the sub throttle opening with respect to the accelerator opening in the first embodiment.

FIG. 6 is a schematic front view showing an instrument panel in the first embodiment.

FIG. 7 is a block diagram showing configurations of an engine ECU and a throttle ECU in the first embodiment.

FIG. 8 is a flowchart showing a “slip suppression flag and fail flag setting routine” executed by the throttle ECU in the first embodiment.

FIG. 9 is a “throttle opening final required value setting routine” executed by the throttle ECU in the first embodiment.
It is a flowchart showing.

FIG. 10 is a graph showing a relationship of a throttle opening final required value with respect to time in the first embodiment.

FIG. 11 is a graph showing a relationship of a throttle opening final required value with respect to time in another embodiment in which the first invention is embodied.

FIG. 12 is a second embodiment of the first invention and the second invention.
3 is a flowchart showing a "throttle opening final required value setting routine" executed by a throttle ECU in the embodiment.

FIG. 13 is a flowchart showing a “μ road determination routine” executed by a throttle ECU in the second embodiment.

FIG. 14 is a flowchart showing a “road surface μ transition counter setting routine” executed by the throttle ECU in the second embodiment.

FIG. 15 is a diagram showing an operation when the characteristic shifts from a low μ road to a high μ road in one embodiment, and is a graph showing a relationship between a throttle opening final required value and an engine output with respect to time.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as internal combustion engine, 8 ... Sub-throttle valve as output adjusting means, 11 ... Step motor as output adjusting driving means, 31 ... Main throttle sensor constituting vehicle running state detecting means, 32 ... Vehicle running state detection A sub-throttle sensor constituting the means 33 ... An accelerator sensor constituting the vehicle traveling state detecting means 34 ... An intake pressure sensor constituting the vehicle traveling state detecting means 35 ... An oxygen sensor constituting the vehicle traveling state detecting means 36 ... Water temperature sensor constituting vehicle traveling state detecting means, 37 ... Rotation speed sensor constituting vehicle traveling state detecting means, 38 ... Cylinder discrimination sensor constituting vehicle traveling state detecting means, 39L, 39R
... A drive wheel speed sensor that constitutes vehicle running state detection means,
40L, 40R ... Driven wheel speed sensor constituting vehicle traveling state detecting means, 41 ... Vehicle speed sensor constituting vehicle traveling state detecting means, 42 ... Shift position sensor constituting vehicle traveling state detecting means, 52 ... Drive control means, Failure detection means,
A throttle ECU that constitutes failure selecting means, failure changing speed reducing means, and maximum output pattern selecting means.

Claims (2)

[Claims] 1. An output adjusting means for adjusting the output of an internal combustion engine, an output adjusting driving means for drivingly controlling the output adjusting means, and a running state of a vehicle equipped with the internal combustion engine. Based on the detection result of the vehicle running state detecting means, the plurality of preset control patterns of the internal combustion engine are selectively used, and the output adjustment is performed so that the control characteristic based on the control pattern is obtained. In an output control device of an internal combustion engine comprising a drive control means for driving and controlling a drive means, a failure detection means for detecting a failure of the vehicle traveling state detection means, and when a failure is detected by the failure detection means, When a failure time selection unit that selects a predetermined control pattern from the plurality of control patterns, and when the vehicle running state detection unit fails, A state in which the output adjustment driving means is driven and controlled by a control pattern selected by the failure selecting means from a state in which the output adjustment driving means is driven and controlled by a control pattern different from the control pattern selected by the failure selecting means. The change speed of the output adjusting drive means when the output adjusting drive means is different from the control pattern selected by the failure selecting means when the vehicle running state detecting means is not in failure. From the drive control state,
And a failure change speed reduction means for reducing the speed of change of the output adjustment drive means to a state in which the output adjustment drive means is driven and controlled by the control pattern selected by the failure time selection means. An output control device for an internal combustion engine, comprising: 2. An output adjusting means for adjusting the output of the internal combustion engine, an output adjusting drive means which is drive-controlled to operate the output adjusting means, and a traveling state of a vehicle equipped with the internal combustion engine is detected. Based on the detection result of the vehicle running state detecting means, the plurality of preset control patterns of the internal combustion engine are selectively used, and the output adjustment is performed so that the control characteristic based on the control pattern is obtained. In an output control device of an internal combustion engine comprising a drive control means for driving and controlling a drive means, a failure detection means for detecting a failure of the vehicle traveling state detection means, and when a failure is detected by the failure detection means, And a maximum output pattern selecting means for selecting a control pattern having the largest output characteristic of the internal combustion engine from among the plurality of control patterns. The output control device for an internal combustion engine, characterized in that.