JP3042294B2 - Driving force control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force control device for controlling a driving force of a driving wheel, and more particularly to a driving force control device for controlling the output of an engine to control the driving force of each driving wheel. This is suitable for a driving force control device.

[0002]

2. Description of the Related Art When a driver attempts to accelerate a vehicle by depressing an accelerator pedal, a friction coefficient state (hereinafter simply referred to as μ) of the road surface is smaller than (lower than) μ assumed by the driver. ), Or when the total grip force (total friction force) as a tire characteristic is small, the drive wheels may slip, and sufficient acceleration and running stability may not be obtained. In order to avoid such a state, the driving force of the driving wheels, specifically, the driving force transmitted from the driving wheels to the road surface is controlled to prevent the driving wheels from slipping, thereby improving the vehicle's acceleration and Various driving force control devices have been developed to ensure running stability.

There are various mechanisms to be controlled by such a driving force control device and control amounts thereof, and one of them is to control the output of an engine. Specifically, for example, a throttle whose opening can be controlled by an actuator is separately provided in an intake system of the engine from a throttle valve (hereinafter also referred to as a main throttle valve) whose opening is directly or indirectly controlled by an accelerator pedal. A valve (hereinafter, also referred to as a sub-throttle valve) is provided. A slip state such as a slip amount or a slip ratio of a wheel is detected or calculated, and when the detected slip state value of the drive wheel becomes larger than a preset slip state, the opening degree of the normally open sub-throttle valve ( The engine output is temporarily reduced by controlling the opening of the drive wheel in the closing direction to thereby temporarily reduce the slip of the drive wheel. It is intended to reduce the state. At this time, the responsiveness of the engine output change control to the throttle opening control is relatively delayed for the purpose of improving the basic output and fuel efficiency of the engine developed in advance. In some cases, the throttle opening control is performed by combining control and feedback control. That is, when the slip state of the drive wheels increases to a certain extent, first, a predetermined throttle opening is performed by feedforward control so as to achieve an engine output such that a drive force of the drive wheels approximately corresponding to the road surface μ is obtained. The sub-throttle valve is closed to a degree, and then the throttle opening of the sub-throttle valve is finely adjusted by feedback control according to the increase or decrease of the slip state of the drive wheels. Generally, in the throttle opening control by the feedback control, it is considered that the slip state of the drive wheel and the throttle opening which is a control amount have a linear relationship.

The problem here is when to start the throttle opening control by the feedback control. For example, before the slip state of the drive wheel converges to a predetermined state, if the throttle state control by linear feedback control and the slip state of the drive wheel is started, the engine by the throttle degree control as described above is started. Due to the response delay of the output control, the slip state of the driving wheels has not yet decreased because the engine output has not yet sufficiently decreased. However, in the throttle opening degree control by the feedforward control, the throttle opening control according to the road surface μ is already performed. The throttle opening control by the feedback control achieves a sufficient throttle opening closing direction control amount. In the throttle opening control by the feedback control, the throttle opening is further closed in a linear manner only in the slip state of the drive wheel which has not yet sufficiently decreased. May try to control in the direction. For this reason, the output of the engine is further reduced (decreased) with a delay corresponding to the control response delay to the throttle opening control from the output for accelerating the vehicle according to the road surface μ. After the slip condition of the driving wheels converges to some extent and the vehicle shifts to the vehicle accelerating state, the vehicle does not actually accelerate, and conversely, the driver does not have enough acceleration to depress the accelerator pedal. The feeling of slowness may be felt as a feeling of deceleration.

In order to solve such a problem, for example, a driving force control device described in Japanese Patent Application Laid-Open No. 4-66336 has been proposed. This driving force control device reduces the engine output for a predetermined time after shifting from the throttle opening control by the feedforward control to the throttle opening control by the feedback control according to the slip state of the drive wheel. Side control gain, specifically, a control gain for calculating a control amount of the throttle opening in the closing direction by multiplying the slip state,
It is set smaller than the throttle opening control by the normal feedback control. According to this drive force control device, the control amount of the throttle opening in the closing direction after the throttle opening control by the feedback control is started is set to be small. The amount of decrease is suppressed to a small extent, and the feeling of deceleration felt by the driver can be suppressed at least after the slip state of the drive wheels converges to some extent and the vehicle shifts to the vehicle accelerating state.

Of course, as described above, there is also a type in which the throttle opening of the main throttle valve is directly controlled in accordance with the depression amount of the accelerator pedal and the reduction amount of the engine output without providing the sub throttle valve. However, the basic throttle opening degree control mode may be considered to be equivalent or almost equivalent to the above.

[0007]

By the way, in the throttle opening control by the feedback control of the driving force control device described in JP-A-4-66336,
The setting of the control gain to a small value and the predetermined time will be considered in detail. For example, as described in the publication, a predetermined time for setting the control gain to a small value is set to a time until the slip state of the drive wheels converges to a predetermined state. When the control gain for calculating the control amount of the throttle opening in the closing direction by multiplying the state is reduced to, for example, “0”, the throttle opening control by the feedback control is substantially performed by the drive wheel. Is not started until the slip state converges to a predetermined state, and during that time, the driving force of the drive wheels according to the road surface μ achieved by the throttle opening control by the feedforward control, that is, the engine output is maintained. become. At least when focusing only on the engine output, after the slip state of the drive wheels converges to some extent and shifts to the vehicle accelerating state,
Since the output of the engine is in accordance with the road surface μ set by the throttle opening control by the feedforward control, the vehicle may exhibit sufficient acceleration.

However, the operation of the above-described conventional driving force control device will be considered for a vehicle equipped with a so-called automatic transmission in which the output of the engine is transmitted to driving wheels via a torque converter. As is known, such a torque converter has an operation region divided into a so-called converter region and a fluid coupling region. Of these, the fluid coupling area is directly or almost directly connected between the input and output shafts of the torque converter, whereas the converter area is characterized by the axial force (torque) of the output shaft of the torque converter compared to that of the input shaft. This is a connection state having a so-called torque amplification action. Therefore, if the normal throttle opening control based on the feedback control is started while the operation region of the torque converter is still in the converter region, for example, the output of the engine becomes the rotation speed or the rotation speed of the output shaft of the engine. The normal throttle opening control by the feedback control reduces the rotational state of the engine output shaft, assuming that the rotational state is linear with the rotational state of the motor. As a result, the speed difference between the input and output shafts of the torque converter disappears. Alternatively, the speed ratio may be increased, and the engine may be forcibly shifted to the fluid coupling region, thereby compensating for the torque amplifying effect of the torque converter. Output is an output that demonstrates sufficient vehicle acceleration in the fluid coupling region of the torque converter Because remote has decreased, resulting in becomes poor vehicle acceleration performance, there is a possibility that it will be felt as a feeling of deceleration to the driver.

The present invention has been developed in order to solve these problems. The present invention selects the engine output control by the feedforward control and the engine output control by the feedback control while detecting the operating region of the torque converter. Alternatively, by adjusting the control amount of the engine output control by the feedback control while detecting the torque amplifying action of the torque converter, it is possible to secure sufficient vehicle acceleration and prevent the driver from feeling deceleration. It is an object to provide a simple driving force control device.

[0010]

According to a first aspect of the present invention, there is provided a driving force control apparatus for controlling the output of an engine via a torque converter as shown in FIG. 1A. A driving wheel slip state detecting means for detecting a slip state of the driving wheel, an operating area detecting means for detecting an operating area of the torque converter, and a load of the driving wheel received from a road surface. A first output reduction amount calculating means for calculating a reduction amount of the engine output corresponding to the above, and a second output for calculating the reduction amount of the engine output in accordance with the slip state of the drive wheel detected by the drive wheel slip state detection means. One of the first output reduction amount calculation unit and the second output reduction amount calculation unit is selected according to the reduction amount calculation unit and the operation region of the torque converter detected by the operation region detection unit. And-option means, is characterized in that an engine output adjusting means for adjusting the output of the engine in accordance with the engine output reduction amount of any of the output reduction amount calculating means selected by said selecting means.

In the driving force control apparatus according to a second aspect of the present invention, as shown in the basic configuration diagram of FIG. It is characterized in that the first output reduction amount calculating means is selected when it is in the converter area, and the second output reduction amount calculating means is selected when it is in the fluid coupling area.

A driving force control apparatus according to a third aspect of the present invention is a vehicle in which the output of an engine is transmitted to driving wheels via a torque converter, as shown in a basic configuration diagram of FIG. A drive wheel slip state detecting means for detecting a slip state of the drive wheel, a torque increase amount detecting means for detecting a torque increase amount of the torque converter, and a reduction amount of the engine output corresponding to a load of the drive wheel received from a road surface. A first output reduction amount calculating means for calculating an engine output reduction amount using a predetermined control gain in accordance with a slip state of the drive wheel detected by the drive wheel slip state detection means.
Output reduction amount calculation means; and control gain setting means for setting the control gain of the second output reduction amount calculation means to be smaller as the torque increase amount of the torque converter detected by the torque increase amount detection means is larger. And an engine output adjusting means for adjusting the output of the engine according to the engine output reduction amount of any of the output reduction amount calculating means.

[0013]

In the driving force control device according to the first aspect of the present invention, as shown in the basic configuration diagram of FIG.
In a vehicle transmitted to a driving wheel via a torque converter inserted between the automatic transmission and the like, the driving wheel slip state detecting means detects, for example, a wheel speed of a driven wheel (a driven wheel). It is considered equivalent to the vehicle speed, and the slip amount of the drive wheel obtained from the vehicle speed, that is, the deviation between the wheel speed of the driven wheel and the wheel speed of the drive wheel, is detected as a slip state detection value of the drive wheel. Further, the operating area detecting means includes:
For example, based on the ratio of the rotational state of the input / output shaft of the torque converter, such as the number of revolutions or the rotational speed, or the ratio of the transmission torque of the input / output shaft of the torque converter, the operating region of the torque converter is, for example, the converter region. It detects whether it is a coupling region. As described above, for example, using the opening control amount in the closing direction of the normally open sub-throttle valve provided in the intake system of the engine (engine), the throttle opening control amount is reduced by the engine output reduction amount. The reduction amount of the engine output corresponding to the load of the driving wheel received from the road surface is a factor equivalent to the road surface μ such as the longitudinal acceleration or the lateral acceleration generated in the vehicle, that is, the direct driving wheel slip state. The first output reduction amount calculating means uses the vehicle state quantity and the input physical quantity which are irrelevant to the above. That is, the first output reduction amount calculation means corresponds to the engine output reduction amount calculation means of the throttle opening control by the conventional feedforward control. On the other hand, the throttle opening control amount of the sub-throttle valve is also referred to as an engine output reduction amount, and the engine output reduction amount is, for example, a drive wheel slip state detection value detected by the drive wheel slip state detection means. It is calculated by the second output reduction amount calculating means simply by multiplying by a predetermined control gain or the like. That is, the second output reduction amount calculating means corresponds to the engine output reduction amount calculating means of the throttle opening control by the conventional feedback control. Then, the selection means is provided, for example, when the operation area of the torque converter detected by the operation area detection means is a converter area, as described in a driving force control device according to claim 2 of the present invention. The first output reduction amount calculation means is selected, and the second output reduction amount calculation means is selected when the engine is in the fluid coupling region, and the engine output reduction of any of the output reduction amount calculation means selected by the selection means is selected. According to the amount, the engine output adjusting means adjusts the output of the engine by, for example, controlling the throttle opening of the sub-throttle valve. Therefore, when the first output reduction amount calculation means is selected by the selection means, the engine output reduction control by the conventional feedforward control is executed when the operation area of the torque converter is the converter area. Therefore, there is no compensation for the torque amplifying action of the torque converter depending on the slip state of the drive wheels. For example, the speed difference between the input and output shafts of the torque converter disappears or the speed ratio increases, and the fluid coupling region Will be migrated to
As a result, the output of the engine does not decrease below the output that exhibits sufficient vehicle acceleration in the fluid coupling region of the torque converter. Further, when the second output reduction amount calculation means is selected by the selection means, the engine output reduction control by the conventional feedback control is executed when the operating area of the torque converter is a fluid coupling area. Therefore, the torque converter is connected between its input and output shafts, that is, the engine and the driving wheels are directly or almost directly connected. At this time, the output of the engine is increased or decreased according to the increase or decrease of the slipping state of the driving wheels. If it is reduced, optimal driving force control according to the vehicle running state or road surface friction coefficient state at that time can be performed.

In the driving force control device according to the third aspect of the present invention, as shown in the basic configuration diagram of FIG. 1B, the torque converter in which the output of the engine is interposed between the automatic transmission and the like is used. In the vehicle transmitted to the drive wheels via the vehicle, the drive wheel slip state detecting means considers that the wheel speed of the driven wheel (driven wheel) is equivalent to the vehicle speed, and this vehicle speed, that is, the driven wheel The slip amount of the drive wheel obtained from the deviation between the wheel speed of the drive wheel and the wheel speed of the drive wheel is detected as a slip state detection value of the drive wheel. Further, the torque increase amount detecting means detects the torque increase amount of the torque converter from, for example, the ratio of the transmission torque of the input and output shafts of the torque converter. As described above, for example, using the opening control amount in the closing direction of the normally open sub-throttle valve provided in the intake system of the engine (engine), the throttle opening control amount is reduced by the engine output reduction amount. The reduction amount of the engine output corresponding to the load of the driving wheel received from the road surface is a factor equivalent to the road surface μ such as the longitudinal acceleration or the lateral acceleration generated in the vehicle, that is, the direct driving wheel slip state. The first output reduction amount calculating means uses the vehicle state quantity and the input physical quantity which are irrelevant to the above. In other words, the first output reduction amount calculation means corresponds to the engine output reduction amount calculation means of the throttle opening control by the conventional feedforward control. On the other hand, similarly, the throttle opening control amount of the sub-throttle valve is defined as an engine output reduction amount, and the engine output reduction amount is, for example, a drive wheel slip state detection value detected by the drive wheel slip state detection means. It is calculated by the second output reduction amount calculating means simply by multiplying by a predetermined control gain or the like. That is, the second output reduction amount calculating means corresponds to the engine output reduction amount calculating means of the throttle opening control by the conventional feedback control. The control gain setting means may control the second output so that the set value decreases as the torque increase amount of the torque converter detected by the torque increase amount detection means increases. The control gain of the reduction amount calculating means is set small. Then, according to the engine output reduction amount of any of the output reduction amount calculation units, the engine output adjustment unit adjusts the output of the engine by performing, for example, throttle opening control of the sub-throttle valve. Therefore, for example, immediately after executing the engine output reduction control according to the engine output reduction amount of the first output reduction amount calculation means corresponding to the engine output reduction amount calculation means of the throttle opening degree control by the feedforward control, When the engine output reduction control is started according to the engine output reduction amount of the second output reduction amount calculation means corresponding to the engine output calculation means of the throttle opening control by the feedback control, the torque of the input / output shaft by the torque converter If the amount of increase is large, that is, if the operating region of the torque converter is still in the converter region, the larger the amount of increase in torque of the torque converter, the smaller the control gain is set. Becomes smaller, and compensates for the torque amplifying action in the converter region of the torque converter. The amount is reduced, for example, the speed difference is gone or the speed ratio between the input and output shafts of the torque converter becomes small,
To prevent the engine output from being forcibly shifted to the fluid coupling region, and as a result, the output of the engine is not reduced below the output that provides sufficient vehicle acceleration in the fluid coupling region of the torque converter. Can be.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing the first embodiment of the present invention, and shows a case of a rear-wheel drive vehicle. In the figure, 10
FL, 10FR are front left wheels, front right wheels, and 10
RL and 10RR indicate a rear left wheel and a rear right wheel serving as drive wheels.
That is, the output (rotational driving force) of the engine (engine) 20
Is the automatic transmission 1 via the existing torque converter 18.
The transmission is transmitted to the automatic transmission 14 and is automatically reduced by the automatic transmission 14 at the selected gear ratio, whereby the driving torque is adjusted. The vehicle is branched to the axle 12, and its rotational driving force is transmitted from both rear wheels 10RL and 10RR to the road surface.

An intake pipe (specifically, an intake manifold) 36 of the engine 20 has an accelerator pedal 4
6, a main throttle valve 48 whose degree of opening from normally closed to open is adjusted and controlled in accordance with the amount of stepping, and a step motor 45 as an actuator. And a sub-throttle valve 44 whose opening is adjusted and controlled. Accordingly, the output (rotational driving force) of the engine 20 is increased by the throttle opening adjustment control in the opening direction of the main throttle valve 48, and the output (engine rotation) of the engine 20 is controlled by the throttle opening adjustment control in the closing direction of the sub throttle valve 44. The rotational driving force may be considered to be reduced (of course, this is not always the case due to the output characteristics of the engine 20, but the description of the present embodiment proceeds in accordance with this basic principle).

The main throttle valve 48 is mechanically linked with the depression amount of an accelerator pedal 46 or an engine controller (not shown) according to a depression amount detection value of an accelerator sensor 47 for detecting the depression amount of the accelerator pedal 46. Is electrically controlled to adjust the throttle opening in the opening direction. The number of steps (rotation angle) of the step motor 45 of the sub-throttle valve 44 is adjusted and controlled by a drive signal from the controller 30 described later, and the throttle opening in the closing direction is adjusted according to the rotation angle. . The sub-throttle valve 44 is provided with a throttle sensor 42. Based on the throttle opening detection value TH detected by the throttle sensor 42, the step motor 4
The number of steps of 5 is feedback-controlled in principle.
Further, the depression amount detection value A of the accelerator sensor 47 is also output to the controller 30.

The torque converter 18 has the same or almost the same configuration as a so-called existing one. An input shaft 18i connected to an output shaft (specifically, a crankshaft) of an engine 20 (not shown) includes: A so-called pump impeller 18b is provided, a so-called turbine liner 18a is provided on the output shaft 18o, and a stator 18c is provided between the two.
Are arranged. As is known, when the rotation speed of the turbine liner 18a is lower than the rotation speed of the pump impeller 18b before the stator 18c starts to idle, as is known, the so-called input / output shafts 18i, 1
There is a torque amplifying action between 8o, and this state or this operation region is called a converter region. On the other hand, when the rotation speed of the turbine liner 18a is equal to or slightly lower than the rotation speed of the pump impeller 18b after the stator 18c starts idling, the so-called input / output shafts 18i and 18o are connected in a directly or almost directly connected state. Alternatively, this operation region is referred to as a fluid coupling region.
In this embodiment, in order to detect such an operation region of the torque converter 18, the input shaft 18i of the torque converter 18 is provided with an input shaft rotation speed sensor 39a, and the output shaft 18o is provided with an output shaft rotation speed sensor 39b. Is provided. Each of these rotation speed sensors 39a and 39b outputs a pulse signal corresponding to the rotation speed of the detection object, as in the existing rotation speed sensor, to an input shaft rotation speed detection value N _in and an output shaft rotation speed detection value N, respectively. _Out is output to a controller 30 described later.

The automatic transmission 14 has the same or almost the same configuration as that of the existing automatic transmission. The automatic transmission 14 drives the actuator unit 32 by a control signal or a drive signal from an automatic transmission control device 34. Transmission 1
The gear ratio in 4 is controlled such that an optimum vehicle reduction ratio according to the engine speed (engine speed) is achieved by using the vehicle speed and the throttle opening as variables in principle. In the present embodiment, the automatic transmission control device 34 exchanges information with the engine controller (not shown) to perform optimization control during normal running of the engine 20 and the automatic transmission 14. The automatic transmission control device 34 outputs the current gear ratio i and the engine rotation speed Ne to the controller 30 described later.

Further, each wheel 10FL~10RR is provided with wheel cylinders 52FL~52RR operated by hydraulic pressure P _M from the brake master cylinder 51 according to the depression force of the brake pedal 50, corresponding wheel by the operation of the wheel cylinder Are individually braked. Thus, the hydraulic pressure control valves 54 for traction control are respectively provided in the brake hydraulic systems of the rear wheels 10RL and 10RR which are the drive wheels.
L and 54R are inserted, and these hydraulic pressure control valves 54L and 54R are inserted.
R have the same specifications and structure as each other, and the spool 55 is pressed to the leftmost position shown in the figure by the return spring 56,
The plunger 57 has a configuration in which the plunger 57 is pressed to the leftmost position shown in the figure by the return spring 58.

[0021] The pressure control valve 54L, 54R are each, outlet port 60 as the wheel cylinder side hydraulic pressure P _M in the master cylinder side of the inlet port 59 in the state shown
Output to the corresponding wheel cylinder, spool 55
When the plunger 57 moves to the right, the communication hole is closed.
Thus, by shutting off the ports 59 and 60, the hydraulic pressure to the wheel cylinder is increased by reducing the volume of the pressure chamber, and the rising hydraulic pressure of the wheel cylinder is maintained when the spool 55 stops moving to the right.

The rightward movement and the stoppage of the spool 55 are controlled by the pressure in the chamber 61, and this pressure is individually controlled by solenoid valves 70L and 70R, respectively. These solenoid valves 70L, 70R also have the same configuration, and when the solenoid 71 is in the off state, it is at the port connection position indicated by the symbol (A), and connects the pressure chamber 61 to the drain circuit 72 and cuts off from the accumulator 73. When the solenoid 71 is turned on by a small current, the port 71 becomes the connection position between the ports as indicated by the symbol (B) and the pressure chamber 61 is connected to the drain circuit 72 and the accumulator 7.
When the solenoid 71 is turned on due to the large current of the solenoid 71, the pressure chamber 61 is cut off from the drain circuit 72 and communicates with the accumulator 73 when the solenoid 71 is turned on due to the large current.

Then, at the position (A) of the solenoid valves 70L and 70R, the pressure chamber 61 is in a non-pressure state, and the spool 55 is brought to the position shown in the drawing.
Is a constant pressure P _C is supplied in the accumulator 73 by the right in the drawing movement of the spool 55, the solenoid valves 70L, the 70R (B)
In the position, the pressure chamber 61 stops supplying and discharging the pressure and the spool 5
5 is held at the right movement position at that time.

Further, the accumulator 73, and accumulator via a check valve 76 the hydraulic pressure from the pump 75 driven by a motor 74, when the accumulated pressure value of the accumulator 73 is in a constant pressure P _C, detects this The controller 30 stops the motor 74 (pump 75) as described later in response to a signal from the pressure switch 77 which is turned off.
The solenoids 71 of the solenoid valves 70L and 70R are similarly driven and controlled by the controller 30.

The wheels 10FL to 10RR are provided with wheel speed sensors 28FL to 28RR, respectively.
Pulse signal corresponding to the rotation speed of the FL~10RR is output to the controller 30 to be described later as a wheel speed detection value Vw _{j (j} = FL~RR). Further, the vehicle is provided with a longitudinal acceleration sensor 40 for detecting longitudinal acceleration generated on the vehicle and a lateral acceleration sensor 26 for detecting lateral acceleration occurring on the vehicle.
Controller Of these, the longitudinal acceleration sensor 40, that regardless of the forward or backward movement of the vehicle, will be described later longitudinal acceleration detection value X _G consisting of a positive a voltage value corresponding to the magnitude of the acceleration acting toward the longitudinal direction of the vehicle Output to 30. Further, the lateral acceleration sensor 26 detects a lateral acceleration detection value Y _G consisting of a positive voltage value according to the magnitude of the acceleration acting in the lateral direction of the vehicle, regardless of whether the vehicle is turning right or left, as will be described later. Output to the controller 30 to be executed.

[0026] The controller 30, as shown in FIG. 3, the frequency converting the pulse signal Vw _FL ~Vw _RR corresponding to the wheel speed from the respective wheel speed sensors 28FL~28RR voltage - voltage converter 81FL~81RR A / D converters 82FL-82RR for converting the conversion outputs of these converters 81FL-81RR into digital signals, and A / D converters for converting the lateral acceleration detection value Y _G of the lateral acceleration sensor 26 into digital values. 83A and the longitudinal acceleration sensor 4
A converting 0 of the longitudinal acceleration detection value X _G into a digital value
A / D converter 83D and an A / D converter 8 for converting the depression amount detection value A and throttle opening detection value TH of the accelerator sensor 47 and the throttle sensor 42 into digital values, respectively.
3B, 83C and a frequency converting the pulse signals N _in in accordance with the input shaft rotational speed of the input shaft rotation speed sensor 39a of the torque converter 18 to the voltage - voltage converter 81a
An A / D converter 83E for converting a conversion output of the converter 81a into a digital signal;
8: a frequency-voltage converter 81b that converts a pulse signal _Nout corresponding to the output shaft rotation speed from the output shaft rotation speed sensor 39b into a voltage, and an A / D converter that converts the conversion output of the converter 81b into a digital signal. A converter 83F and each A / D
A microcomputer 84 to which conversion output signals of the converters 82FL to 82RR and 83A to 83F, an output signal of the pressure switch 77, and a signal from the automatic transmission control device 34 are input, and a solenoid valve 70L output from the microcomputer 84. , 70R, and D / A converters 87L and 87R for converting command values to analog values, and conversion outputs of these D / A converters are input. Based on these, excitation currents for solenoids of solenoid valves 70L and 70R are determined. i _SL,
solenoid drive circuits 88L and 88R that output i _SR ,
Motor drive circuits 89 and 90 for rotating the step motor 45 and the motor 74 in accordance with the motor drive signal output from the microcomputer 44 are provided.

Here, the microcomputer 84 includes at least an input interface circuit 84a, an output interface circuit 84b, an arithmetic processing unit 84c, and a storage device 8
4d, and the arithmetic processing unit 84c includes a wheel speed detection value Vw _FL ... From the wheel speed sensors 28FL to 28RR.
Wheels 10RL After a drive wheel with Vw _RR, slip ratio 10RR S _L, S _R and its change rate V _SL, calculates V _SR, the rear wheel slip ratio S _L, S _R and its change rate V _SL, rear wheel is the drive wheel based on the V _SR 10RL,
10RR side of the wheel cylinders 52RL, and controls the hydraulic fluid pressure 52RR (brake fluid pressure), from the torque converter input shaft rotational speed detection value N _in and the output shaft rotational speed sensor 39b from the input shaft rotational speed sensor 39a detects actuation region of the torque converter 18 based on the torque converter output shaft rotation speed detection value n _out, wheels 10RL after a drive wheel simultaneously calculates or detects the current amount of slip S _(n) of the 10RR, the current Slip amount S
_{When (n)} exceeds a predetermined value S ₀ , the longitudinal acceleration detection value X _G from the longitudinal acceleration sensor 40, the lateral acceleration detection value Y _G from the lateral acceleration sensor 26, and the current automatic transmission 1
The required target output (target driving torque) T ^* _(n) of the engine 20 is calculated based on the gear ratio i of the sub-throttle valve 44 based on the target driving torque T ^* _(n) and the engine speed Ne. The target throttle opening θ ^* is calculated, and a rotation drive signal for achieving the target throttle opening θ ^* is output to the step motor 45, that is, by feedforward control that does not respond only to a so-called slip state of the drive wheels. Start throttle opening control, and then
The throttle opening control by the feed-forward control for the predetermined period, eventually the ratio of the torque converter input shaft rotational speed detection value N _in and the output shaft rotational speed detection value N _out N
Is larger than a predetermined value N ₀ , it is determined that the operation region of the torque converter 18 has become the fluid coupling region, and the rear wheels 10 RL and 10, which are the drive wheels, are determined.
When the current slip amount S _{(n) of} RR exceeds the peak and becomes equal to or less than a predetermined value S ₂ , the front-rear acceleration detection value X _G and the lateral acceleration detection value Y _G and the average front wheel speed V equivalent to the vehicle body speed are obtained.
Wheels 10RL After a drive wheel based on _F, and calculates the target slip amount S ^* of 10RR, the target slip amount S ^* and the current slip amount S _(n) and the previous amount of slip S
_(n-1) and using a predetermined proportional control gain K _P and the integral control gain K _I calculates the current engine driving torque decrease amount [Delta] T _(n) using this current engine drive torque decrease amount [Delta] T _{(n ) And the} previous target drive torque T ^* _(n-1) to calculate a target drive torque T ^* _(n) . Based on the target drive torque T ^* _(n) and the engine speed Ne, the sub-throttle valve Throttle opening control by feedback control according to a so-called driving wheel slip state, which calculates a target throttle opening θ ^* and outputs a rotation drive signal for achieving the target throttle opening θ ^* to the step motor 45. Is started, and the output reduction control of the engine is executed.

The storage device 84d includes an arithmetic processing device 84
with previously stores a processing program required for the calculation of c, sequentially stores the processing result of the arithmetic processing unit, and wheel 10RL after the a driving wheel, the slip ratio S _L of 10RR, S _R and its change Rate (slip rate change speed) V _SL ,
Solenoid valve and a V _SR 70L, previously stores a control mode conversion map that sets the control mode of the 70R.

First, the wheel cylinders 52RL on the rear wheels 10RL, 10RR, which are drive wheels, are executed by the arithmetic processing unit 84c of the microcomputer 84.
The calculation process for controlling the hydraulic fluid pressure (brake fluid pressure) of 52RR will be described with reference to FIGS. In addition,
The arithmetic processing for the brake fluid pressure control is performed by the drive force control device for enabling the drive force control described in Japanese Patent Application Laid-Open No. 4-274914 previously proposed by the present applicant. This is an excerpt of the arithmetic processing, and the content of the arithmetic processing will be briefly described with reference to the publication as required. The control mode of the hydraulic pressure control valves 54L and 54R used for outputting the control command value of the solenoid valves 70L and 70R for the brake hydraulic pressure control is retrieved from a control map of FIG. The map is stored in the storage device 84d in advance. The control map will be described briefly.
Slip ratio changing speed V _SL calculated from the wheel speeds detected value Vw _j detected in 8FL~28RR, V _SR and the slip ratio S _L, by a S _R, rapid decompression, gentle vacuum, holding pressure, Yuruzo圧5 modes are set.

This arithmetic processing is executed by the microcomputer 84 as a timer interrupt for every predetermined time ΔT of, for example, about 5 msec. First, in step S101, each wheel speed detection value Vw from each wheel speed sensor 28FL-28RR.
_j (j = FL to RR) is read.

Next, the flow shifts to step S102, where an output signal from the pressure switch 77 is read. Next, the process proceeds to step S103, based on the wheel speed detection values Vw _{FL to} Vw _RR read in step S101, the driving wheels for the front left and right wheels 10FL and 10FR, which are driven wheels equivalent to the vehicle speed. From the ratio of the deviation between the rear left and right wheels 10RL, 10RR, the following formulas 1 and 2 are operated to calculate the current values S _{L (n)} , S of the slip ratios of the rear wheels 10RL, 10RR to be the driving wheels.
Calculate _{R (n)} .

[0032] _{S L (n) = (V} RL -V FL) / V FL ......... (1) S R (n) = (V RR -V FR) / V FR ......... (2) Next step Proceeding to S104, the step S10
3. The current values S _{L (n)} and S _{R (n) of} the slip rate calculated in Step 3 and the previous value S of the slip rate calculated during the previous timer interrupt processing.
_{Using L (n-1)} and SR _(n-1) , the following equations 3 and 4 are operated to calculate the slip rate change speeds _VSL and _VSR .

V _SL = S _{L (n)} -S _{L (n-1)} (3) V _SR = S _{R (n)} -S _{R (n-1)} (4) Next step Proceeding to S105, the step S10
3 and the current value of the slip ratio S _{L (n)} calculated in S104,
Based on S _{R (n)} and the slip rate change speeds V _SL , V _SR ,
The control mode of the hydraulic pressure control valves 54L, 54R is set with reference to the braking pressure control mode conversion map of FIG. 5, and then the process proceeds to step S106, where the command value corresponding to the control mode set in step S105 is set. Drive circuits 88L, 88
After outputting to R, the process proceeds to step S107.

In the step S107, it is determined whether or not the switch signal of the pressure switch 77 read in the step 102 is in an ON state. When the switch signal is in the ON state, the accumulated pressure of the accumulator 73 becomes lower than a set value. It is determined that the motor 7
For example, after outputting a drive signal having a logical value of “1” to drive the motor 4 to the motor drive circuit 90, terminating the timer interrupt processing and returning to the predetermined main program, and when the switch signal is in the OFF state, the accumulator 73 Is determined to be greater than or equal to the set value, and the process proceeds to step S109.
For example, a drive signal of a logical value “0” for stopping the motor 74 is output to the motor drive circuit 90, and then the timer interrupt process is terminated and the process returns to the predetermined main program.

Therefore, assuming that the vehicle is stopped with the engine idling, the wheel speed detection values Vw _{FL to} Vw _RR are zero in this state. slip rate of the current value _{S L (n), S R} (n) also becomes zero, and the step S1
Since the slip rate change speeds V _SL and V _SR calculated in step 04 are also zero, the slow pressure reduction mode is set in step S105 with reference to the map shown in FIG. A current command value that alternates with zero every predetermined time is output to the D / A converters 87L and 87R, respectively. Thereby, the solenoid driving circuits 88L, 88
An exciting current that alternately repeats a small current value and zero from R is output to the solenoid 71 of the solenoid valves 70L and 70R, and these solenoid valves 70L and 70R are switched to their switching positions (A) and (B).
The pressure chambers 61 of the hydraulic pressure control valves 54L and 54R are communicated with the tank at predetermined time intervals, so that the pressure is gradually reduced. At this time, when the pressure in the pressure chamber 61 is at or near atmospheric becomes a state where the spool 55 is shifted leftward by the return spring 56 as shown in FIG. 2, the hydraulic pressure P _M from the brake master cylinder 50 Wheel cylinders 52RL, 5 of rear wheels 10RL, 10RR
Becomes ready supply to 2RR, when the time that depress the brake pedal 50, the brake fluid pressure P _M is the rear wheel side wheel cylinders 52RL generated in the brake master cylinder 51 at that time, the braking state is supplied to 52RR maintain.

[0036] From this stopped state, when releasing the depression of the brake pedal 50, the brake fluid pressure P _M that is generated in the brake master cylinder 51 is at or near atmospheric, the front wheel side and rear wheel side wheel Cylinder 5
The pressure of 2FL to 52RR becomes the atmospheric pressure or almost the atmospheric pressure, and the braking state is released. When the accelerator pedal 46 is depressed from this state, the output (rotational driving force) of the engine increases, and this output is used as the driving force as the rear wheel 10R.
L, 10RR, the vehicle enters a starting state. Thus, when the vehicle is in the starting state, each wheel 10
FL-10RR starts rotating, and each wheel speed sensor 28F
The wheel speed detection values Vw _{FL to} Vw _RR of L to 28RR increase. At this time, when the vehicle starts slowly on a high-μ road surface such as a dry asphalt road surface or a concrete road surface, the rear wheels 10FL and 10RR serving as the drive wheels do not cause much slip, and the drive wheels calculated in step S103 are not slipped. The current values S _{L (n)} and S _{R (n)} of the slip rates are values near zero, and the slip rate change speeds V _SL and V _SR calculated in step S104 are also small values.
L and 70R also maintain the slow pressure reduction mode while maintaining the hydraulic pressure control valve 54.
The spool 55 of L, 54R is held at the left movement position. At this time, if the brake pedal 46 is not depressed, the brake hydraulic pressure P generated by the brake master cylinder 51
_M becomes the atmospheric pressure or almost the atmospheric pressure, and in this state, the solenoid valves 70L, 70R and the hydraulic pressure control valves 54L, 54R set in the gentle pressure reduction mode operate the front wheel side and rear wheel side wheel cylinders 52FL-52RR. The pressure becomes the atmospheric pressure or almost the atmospheric pressure, and no braking force is applied to the wheels 10FL to 10RR.

When the vehicle starts slowly on a low μ road such as a frozen road, a snowy road, or a rainy road, or suddenly starts on a high μ road such as a dry road, the vehicle slowly starts on the high μ road. compared with the left and right rear wheels 10RL serving as a driving wheel, the 10RR, increased slip slightly from the traction loss caused by the driving force, thus then wheel speed detected value Vw _RL, in the step S103 with increasing Vw _RR As the current values S _{L (n)} and S _{R (n) of the} calculated slip ratios increase, step S10
When the slip rate change speeds V _SL and V _SR calculated in step 4 increase in the positive direction, the slow pressure increase mode (or the rapid pressure increase mode) is set in step S105, and accordingly, the electromagnetic pressure is increased in step S106 in step S106. The command value for instructing the large excitation current and the zero command value for the valves 70L, 70R are alternately repeated (or the command value for instructing the large excitation current is continuously output) to the solenoid drive circuits 88L, 88R. As a result, a large excitation current is output from these drive circuits 88L and 88R to the solenoid valves 70L and 70R, and these solenoid valves are switched to the position (C). Therefore, the pressure P _A in the accumulator 73 is the electromagnetic valve 70L, hydraulic pressure control valve 54L via 70R, since it is supplied to the pressure chamber 61 of the 54R, the spool 55 is moved rightward against the return spring 56. When the right end of the spool 55 contacts the left end of the plunger 57, the input port 59 and the output port 60 are cut off.
When the plunger 57 moves rightward, the pressure in the pressure chamber on the side of the plunger 57 increases.
L, 10RR side wheel cylinders 52RL, 52RR
And a braking force acts on the rear wheels 10RL, 10RR, whereby the rear wheels 10RL, 1 serving as driving wheels
Since the slip of 0RR is suppressed, the driving force to the rear wheels 10RL and 10RR, which are the driving wheels, is regulated to a necessary size at the time of the start, and the total driving force of the entire vehicle is improved.

Further, when the vehicle attempts to start suddenly on the low μ road surface as described above, it becomes a drive wheel as compared with when the vehicle suddenly starts on the high μ road surface or when the vehicle starts slowly on the low μ road surface. Left and right rear wheels 1
At 0RL and 10RR, the slip is further increased due to the traction loss due to the driving force, so that the wheel speed detection values Vw _RL and Vw _RR are increased thereafter in step S10.
The current values S _{L (n)} and S _{R (n)} of the slip rates calculated in Step 3 increase, and the slip rate change speeds V _SL and V _SR calculated in Step S104 increase in the positive direction. In step S105, the rapid pressure increase mode is set,
In response to this, in step S106, the solenoid valves 70L, 70
By continuously outputting a command value for instructing the large excitation current to R to the solenoid drive circuits 88L and 88R, the large excitation current is output from these drive circuits 88L and 88R to the solenoid valves 70L and 70R. These solenoid valves are switched to the position (C). Therefore, the pressure P _{A of the} accumulator 73 is supplied to the pressure chambers 61 of the hydraulic pressure control valves 54L, 54R via the solenoid valves 70L, 70R, so that the spool 55 moves rightward against the return spring 56,
When the right end of the spool 55 abuts on the left end of the plunger 57, the input port 59 and the output port 60 are cut off, and the spool 55 and the plunger 57 move rightward while maintaining this cut off state, so that the plunger 57 side The pressure in the pressure chamber increases, and this is the left and right rear wheels 10RL, 10RR.
Is transmitted to the side wheel cylinders 52RL, 52RR, and a braking force acts on the rear wheels 10RL, 10RR.
As a result, the slip of the rear wheels 10RL, 10RR serving as the drive wheels is suppressed, so that the rear wheels 10R serving as the drive wheels are suppressed.
The driving force to L, 10RR is regulated to a necessary size at the time of the start, and the total driving force of the entire vehicle is improved.

However, when the vehicle starts on a so-called split road in which the left half of the running road is, for example, a dry high μ road surface and the right half is, for example, a frozen low μ road surface, the left driving wheel 1
Drive wheel 10 on the right side with respect to wheel speed detection value Vw _{RL of} 0RL
Since the wheel speed detection value Vw _{RR of RR} becomes a large value, FIG.
The current values S _{L (n)} and S _{R (n) of the} drive wheel slip ratios calculated in step S103 of the above calculation process are also set to the right with respect to the current value S _{L (n) of the} left rear wheel side slip ratio. Rear wheel slip ratio S
_{R (n)} becomes a large value, and the slip rate change rate V _SR on the right rear wheel side becomes larger than the slip rate change rate V _SL on the left rear wheel side calculated in step S104.
Therefore, in step S105, the brake hydraulic pressure control mode of the hydraulic pressure control valve 54L for the wheel cylinder 52RL of the left rear wheel 10RL is set to, for example, a gentle pressure reduction mode, whereas the wheel cylinder 52RR of the right rear wheel 10RR is set. The brake hydraulic pressure control mode of the hydraulic pressure control valve 54R is set to, for example, a rapid pressure increase mode, and the wheel cylinder 52 to the drive wheel on the low μ road surface side, here, the right rear wheel 10RR, is set.
The braking fluid pressure on the RR is relatively greater than the braking fluid pressure on the drive wheels on the high μ road surface, in this case, the wheel cylinder 52RL on the left rear wheel 10RL, and as a result, on the low μ road surface side where slip is likely to occur. Since the braking force of the driving wheel is increased and the driving force of the driving wheel is reduced, and the braking force of the driving wheel on the high μ road surface which is hard to slip is reduced, the traction loss between the two μ road surfaces is canceled out. The driving force required for the road surface μ is transmitted to the driving wheels, and as a result, the total driving force of the entire vehicle is improved.

In addition, the same braking force control as described above, that is, the driving force control is executed in accordance with the slippage of each driving wheel generated during turning, but the deviation of the rotation speed of the inner and outer turning wheels is determined as follows. Since the slip rate and the slip rate change rate of the drive wheel are calculated using the wheel speed of the corresponding front wheel as a reference value, the slip state in which the deviation of the magnitude of the turning radius, that is, the rotation speed of the inner and outer turning wheels is removed. The driving force improvement control can be performed by the optimal braking force control depending on the driving force.

Next, the basic principle of the driving force control by the throttle opening control of the sub-throttle valve 44 executed in this embodiment will be described. Also in the throttle opening control of the present embodiment, feedforward control that does not consider the slip state of the drive wheels, specifically, controls the throttle opening based on a physical quantity or the like generated or acting on the vehicle,
In consideration of the slip state of the drive wheels, feedback control for controlling the throttle opening based on the detected slip state value is also used. Of these, the throttle opening control based on the feedback control based on the detected value of the slip state of the drive wheel can be easily understood from the fact that the vehicle motion is basically controlled by a feedback control system involving a driver. On the other hand, throttle opening control by feedforward control that does not consider the slip state of the drive wheels
As described above, the basic design philosophy of the engine 20 is at least emphasis on power enhancement and fuel efficiency improvement at least now. For example, even if the throttle opening of the sub-throttle valve 44 is controlled in the closing direction, it is substantially It takes a little time before the output of the engine 20 decreases, that is, the control response is slow, whereas the excessive slip state of the drive wheels in an actual vehicle means that not only the acceleration performance but also the vehicle behavior, This is executed in order to achieve both the contradictory purpose and the effect that the slip state of the drive wheel must be suppressed as quickly as possible because it is related to the running stability.

Specifically, in the present embodiment, in the throttle opening control by the feedforward control, first, the longitudinal acceleration detection value X _G from the longitudinal acceleration sensor 40 and the lateral acceleration detection value Y _G from the lateral acceleration sensor 26 are detected. Using the current gear ratio i of the automatic transmission 14 and the current value Tf _(n) of the engine drive torque for achieving the current vehicle behavior on the road surface, based on the following equation (5 ₎ , Calculation is performed in accordance with a predetermined function f set in consideration of the tire characteristics, and the current value Tf _(n) of the driving torque is set to the current value T ^* _(n) of the target driving torque. The current value Tf _(n) of the drive torque is calculated and set by a control map search or the like according to, for example, each variable, that is, the longitudinal acceleration detection value X _G , the lateral acceleration detection value Y _G , and the gear ratio i. Is also good.

Tf _(n) = (1 / i) · f (X _G , Y _G ) (5) On the other hand, in the throttle opening control by the feedback control, first, as will be described in detail later, the vehicle speed is controlled. the average front wheel speed V _F and the longitudinal acceleration sensor 4, which is calculated as an equivalent value
Longitudinal acceleration detection value from 0 X _G and the lateral acceleration sensor 26
, The target slip amount S ^* is calculated according to the following equation (6) using the lateral acceleration detection value Y _G from the following equation. Where K ₁ ,
K ₂ and K ₃ are proportional constants set in advance.

S ^* = K ₁ · V _F + K ₂ · X _G + K ₃ · Y _G (6) Next, feedback control of the target slip amount S ^* and the driving force as described in detail later. the target physical quantity rear wheels is calculated drive wheel as 10RL, current value S of the wheel slip amount after obtained from the deviation between the average rear wheel speed V _R of 10RR and the average front wheel speed V _{F (n),} and the previous The previous value S of the rear wheel slip amount calculated during calculation and updated and stored
_{Using (n-1)} , the present value ΔT _(n) of the increase / decrease of the driving torque of the engine is calculated according to the following equation (7 ₎ . In the equation, K _P
Is a proportional control gain, and K _I is an integral control gain. In the present embodiment, a predetermined value K _P0 and a predetermined value K _{I0 are} respectively set in advance.
It should be understood that it is equal to.

ΔT _(n) = K _P (S _(n) −S _(n−1) ) + K _I (S _(n) −S ^* ) (7) Next, this drive torque increase / decrease The previous value T ^{* of the} value ΔT _(n) and the updated and stored target drive torque of the engine ^.
_{Using (n-1)} , the current value T ^* _(n) of the target drive torque is calculated according to the following equation (8 ₎ . T ^* _(n) = T ^* _(n-1) + ΔT _(n) (8) Then, the present value T ^* _{(n) of} the target drive torque calculated by the above equation (5) or (8) and the current state of the engine Rotation speed Ne
_{Using (n)} , the present value θ ^* _(n) of the target throttle opening in the closing direction of the normally open sub-throttle valve 44 is set in advance in consideration of vehicle characteristics and tire characteristics according to the following equation (9 ₎ . It is calculated according to a predetermined function g. The current value θ ^* _(n) of the target throttle opening is set to “0” when the sub-throttle valve 44 is fully opened, and increases in the forward direction as a control amount in the closing direction.

Θ ^* _(n) = g (T ^* _(n) , Ne _(n) ) (9) According to the current value θ ^* _(n) of the target throttle opening calculated in this manner, For example, when the current value θ ^* _{(n) of the} target throttle opening is larger than the throttle opening detection value TH of the throttle sensor 42, a forward rotation signal is output to the step motor 45 to move in the closing direction. When the current value θ ^* _{(n) of the} target throttle opening is smaller than the throttle opening detection value TH of the throttle sensor 42, a reverse rotation signal is sent to the step motor 45. Is output to reduce the sub-throttle opening in the closing direction.

The problem here is when to start and when to end the throttle opening control by the feedforward control, or when to start and when to end the throttle opening control by the feedback control. As described above, if the switching (transition) from the throttle opening control by the feedforward control to the throttle opening control by the feedback control is performed only for the slip state of the drive wheels or the behavior of the vehicle, a torque converter is installed. In the vehicle as in the present embodiment, a problem of the effect of amplifying the output torque of the engine occurs.

That is, as described above, such a torque converter has an operation region divided into a so-called converter region and a fluid coupling region. Among them, the fluid coupling region is in a state of being directly or almost directly connected between the input and output shafts of the torque converter, whereas the converter region is configured to apply the axial force (torque) of the output shaft of the torque converter to the input shaft, that is, the engine. This is a connected state having a so-called torque amplifying action that amplifies as compared with that of the output shaft. Therefore, if the normal throttle opening control by the feedback control is started while the operating region of the torque converter is still in the converter region, for example, the normal throttle opening control by the feedback control becomes the output shaft of the engine. As a result, the speed difference between the input and output shafts of the torque converter disappears or the speed ratio increases, and the torque converter is forcibly shifted to the fluid coupling region. Compensates for the torque amplification effect due to
In such a case, the output of the engine is lower than the output that provides sufficient vehicle acceleration in the fluid coupling region of the torque converter, and consequently the vehicle acceleration becomes poor, which causes the driver to decelerate. There is a possibility that it will be felt as a feeling.

In view of such a torque amplifying effect of the torque converter, in this embodiment, the throttle opening control by the feedforward control and the throttle opening control by the feedback control are set as follows. First,
The following physical quantities are calculated as factors of the throttle opening control. As described above, the rotational driving force of the engine is basically divided and transmitted to both the rear left and right wheels 10RL and 10RR which are the driving wheels. Wheel speed detection value Vw
_RL, the Vw _RR, calculates the average rear wheel velocity V _R in accordance with the following 10 formula.

[0050] _{V R = (Vw RL + Vw} RR) / 2 ......... (10) Further, the vehicle speed to be compared of the average rear wheel speed V _R is inherently, the left and right wheels before which is the driven wheel 10FL, 10F
The front left and right wheels 10FL, 1 which are both driven wheels are assumed to be equivalent to the average of the wheel speed detection values Vw _FL , Vw _FR of R.
Wheel speed detection value Vw _FL of 0FR, from Vw _FR, calculates the average front wheel speed V _F according to the following 11 formula.

[0051] V _F = addition _{(Vw FL + Vw FR) /} 2 ......... (11), wherein the difference between the average rear wheel speed V _R and the average front wheel speed V _F, the rear wheel 10RL, a mean of 10RR _{Let the} slip speed be the current value S _(n) of the drive wheel slip amount,
It is calculated according to equation (2). S _(n) = V _R −V _F (12) The current value S _(n) of the drive wheel slip amount and the previous value S _(n−1) of the drive wheel slip amount in the previous calculation process are calculated. Is calculated according to the following equation (13) as a change amount α of the slip amount.

Α = S _(n−1) −S _(n) (13) Further, the torque converter input shaft rotation speed detection value N _in
And the ratio between the output shaft rotation speed detection value N _out and the input / output shaft rotation speed ratio N is calculated in accordance with the following equation 14. N = N _out / N _in (14) As is known here, the ratio of the rotation speeds of the input / output shafts 18i and 18o of the torque converter 18, that is, the input / output shaft rotation speed ratio N is a constant efficiency η. under the input and output shafts 18i of the torque converter 18, because it is equivalent to the inverse ratio of the transmission torque ratio T of 18o, when the input shaft rotation speed ratio N is less than the predetermined value N ₀ is the input and output shafts 18i of the torque converter 18, there is a torque amplifying effect at 18o, i.e. from the operating range of the torque converter 18 is considered to be the converter region, by setting the predetermined value N ₀ appropriately, O The shaft rotation speed ratio N is a predetermined value N
₀ to the reset state of the fluid coupling area control flag F to _T "0" if smaller than the other hand, when the input shaft rotation speed ratio N is not smaller than the predetermined value N ₀ is the torque converter 18 Input / output shafts 18i, 18
Since o is in a directly or almost directly connected state, that is, the operating region of the torque converter 18 is considered to be a fluid coupling region, the fluid coupling region control flag F _T is set to “1”.

The current value S of the driving wheel slip amount
_{When (n)} is larger than a predetermined value S ₀ and the change amount α of the slip amount is smaller than a predetermined negative value α ₀ which is a certain negative value, control for throttle opening control by the feedforward control is performed. flag (hereinafter, simply referred to as feedforward control flag) is in the set state of the _F F "1". Here, the fact that the current value S _(n) of the drive wheel slip amount is larger than a certain predetermined value S ₀ means that the rear wheels 10 that are the drive wheels
RL, since the slip amount of 10RR can be judged to be excessive, by setting the predetermined value S ₀ as appropriate, the throttle opening control start by the feed forward control to be executed from the meaning as described above one One criterion can be used. Also, in the case where the current value S _(n) of the drive wheel slip amount sharply increases with respect to the previous value S _(n-1) as described above, it should be executed from the above-described meaning. It can be used as one criterion for the start of the throttle opening control by the feedforward control. Here, the change amount α of the slip amount calculated from the above equation 13 should be a negative value at such a time. Yes (What becomes if the drive wheels slip amount S _(n) itself is, because it is deviation to the average front wheel speed V _F of the average rear wheel speed V _R), thus the predetermined value alpha ₀ is appropriate to a certain negative value Will have to be set.

[0054] Here, the when feedforward control flag F _F is in the set state of "1", but not to start the throttle opening control by the feed forward control described above, by such feed-forward control When the throttle opening control is started, the throttle opening of the sub-throttle valve 44 is inevitably controlled in the closing direction, and as described above, according to FIG. As a result, the current value S _(n) of the drive wheel slip amount soon begins to decrease beyond the peak point. Therefore, the current drive wheel slip amount peak value _{SP (n-1)} is used as the drive wheel slip amount current value S _(n) .
The current value of the drive wheel slip amount at the time of the previous calculation, which was previously updated and stored as the peak value _{SP (n-1)} of the drive wheel slip amount (that is, the time when the previous value S _(n-1) of the drive wheel slip amount was lower ₎ in updating stored, and the value obtained by subtracting the present value S _(n) of the drive wheels slip amount from the current drive-wheel slip amount of the peak value S _{P (n-1)} is, than a certain predetermined positive value alpha ₂ Is also smaller,
Assuming that the slip amount of the rear wheels 10RL and 10RR, which are the driving wheels, has stably exceeded the peak, the peak control flag F
_P is set to "1". Then, the peak control flag _FP is in the set state of "1", that is, the present value S of the drive wheel slip amount which has started to decrease beyond the peak point.
_{When (n)} falls below a predetermined value S ₂ , it can be determined that the slip amount of the drive wheel is in a stable convergence direction.
The predetermined value slip convergence control flag F _S by appropriately setting the S ₂ to the set state of "1".

[0055] Then, when the fluid coupling area control flag F _T and the slip amount convergence control flag F _S is in the set state of both "1", the control flag for the throttle opening control by the feedback control (hereinafter,
F _C is set to “1”. In this case, the actual value S _{(n) of the} drive wheel slip amount is not actually larger than the predetermined value S ₀ and the change amount α of the slip amount is not larger than the predetermined value α _0. One said when feedback control flag F _C is in the set state of "1", the throttle opening control is started the first time by the feedback control.

Next, a calculation process for executing the throttle opening control in the closing direction of the sub-throttle valve 44 based on the principle of the present invention will be described with reference to FIG. Each control flag in the figure is as described above. This arithmetic processing is performed by, for example, 10 msec. In the arithmetic processing unit 84c of the microcomputer 84.
Executed by timer interruption processing every predetermined time ΔT degree, first reads the lateral acceleration detection value Y _G from the longitudinal acceleration detection value X _G and the lateral acceleration sensor 26 from the longitudinal acceleration sensor 40 in step S1.

Next, the routine proceeds to step S2, where the detected wheel speed values Vw _j (j) from the wheel speed sensors 28FL to 28RR are used.
= FL to RR). Next, the process proceeds to step S3, in which the rear wheels 10RL, 10 read in step S2 are read.
Wheel speed Vw _RL of RR, using Vw _RR, calculates the average rear wheel speed V _R in accordance with the 10 equations.

Next, the process proceeds to step S4, in which the wheel speeds V of the front wheels 10FL and 10FR read in step S2 are read.
w _FL, with Vw _FR, it calculates a vehicle speed equivalent to the average front wheel speed V _F in accordance with the 11 equations. Next, the process proceeds to step S5, in which the average rear wheel speed V _R calculated in step S3 is calculated.
And using the average front wheel speed V _F calculated in step S4, the current value S of the driving wheel slip amount in accordance with the 12 formula
_(n) is calculated.

Next, the routine proceeds to step S6, where the previous value S _(n-1) of the drive wheel slip amount updated and stored in the storage device 84d in the previous calculation processing is read. Next, step S
7, the current value S _(n) of the drive wheel slip amount calculated in the step S5 and the previous value S _{(n -1)} of the drive wheel slip amount read in the step S6 are used to calculate the 13
The change amount α of the slip amount is calculated according to the equation.

Next, the operation proceeds to step S8, where the input shaft rotation speed sensor 39 provided in the torque converter 18 is provided.
It reads the detected output shaft rotational speed detection value N _out at the detected input shaft rotational speed detection value N _in and the output shaft rotational speed sensor 39b in a. At the next step S9, using the read written input shaft rotational speed detection value N _in and the output shaft rotational speed detection value N _out at step S8, calculated output shaft speed ratio N according to the 14 formula I do.

[0061] Next, the process proceeds to step S10, step S9 input shaft speed ratio N calculated in it is determined whether the larger than a predetermined value N ₀ set in advance, the input and output shafts If the rotation speed ratio N is larger than the predetermined value N ₀ , the process proceeds to step S11; otherwise, the process proceeds to step S12. In the step S11, the input / output shaft rotation speed ratio N is set to the predetermined value N _0.
For greater than the operating range of the torque converter 18 from the set to "1" to the fluid coupling area control flag F _T it is determined that the fluid coupling region, the process proceeds to step S13.

[0062] On the other hand, in step S12, for the input and output shaft rotational speed ratio N the equal to or less than the predetermined value N ₀ to set in advance, it is determined that the operating region of the torque converter 18 is a converter region and the the fluid coupling area control flag F _T is reset to "0", the process proceeds to step S13. In the step S13,
It is determined whether or not the current value S _(n) of the drive wheel slip amount calculated in step S5 is larger than the predetermined value S ₀ , and the current value S _{(n) of the} drive wheel slip amount is determined. If greater than the predetermined value S ₀ and goes to step S14, otherwise it proceeds to step S15.

In step S14, the peak value _{SP (n-1)} of the drive wheel slip amount updated and stored in the storage device 84d during the previous calculation processing is read.
Move to 16. In the step S16, it is determined whether or not the current value S _(n) of the driving wheel slip amount calculated in the step S5 is larger than the peak value _{SP (n- 1) of} the driving wheel slip amount read in the step S14. It is determined that the current value S _(n) of the drive wheel slip amount is the peak value S of the drive wheel slip amount.
If it is larger than _{P (n-1)} , the process moves to step S16; otherwise, the process moves to step S18.

In step S17, the present value S _(n) of the drive wheel slip amount is changed to the peak value S of the drive wheel slip amount.
_After being updated and stored in the storage device 84d as _{P (n-1)} , the flow shifts to step S15. In the step S18,
It is determined whether the current value a value obtained by subtracting the S _(n) of the drive wheels slip amount from the drive wheel slip amount of the peak value S _{P (n-1)} is whether the preset predetermined value alpha ₂ smaller, so If so, the process proceeds to step S19; otherwise, the process proceeds to step S15.

At the step S15, at the step S15
13 or step S14~S17 or step the current values of the drive wheels slip because not satisfied all of the conditions of S18 S _(n) is still determined not to exceed a peak, the peak control flag F to _P "0 Then, the process moves to step S20. On the other hand, in step S19, it is determined that the current value S _(n) of the drive wheel slip amount has exceeded the peak since all the conditions of step S13, steps S14 to S16, and step S18 are satisfied, and the peak control is performed. After setting the flag _FP to "1", the process proceeds to step S21.

[0066] The step S21, the driving wheel slip amount of the current value S _(n) is determined whether the predetermined value S ₂ is smaller than or not the threshold of slippage convergence, the drive wheels slip amount of the current value If S _(n) is smaller than the predetermined value S _{2, the process} proceeds to step S22; otherwise, the process proceeds to step S20. In step S20, in the calculation processing steps up to step S21, it is determined that the slip of the rear wheels 10RL and 10RR, which are still driving wheels, does not tend to converge, and the slip amount convergence control flag F _S is reset to “0”. Then, the process proceeds to step S23.

On the other hand, in step S22, in the calculation processing steps up to step S21, it is determined that the slip of the rear wheels 10RL and 10RR, which are the driving wheels, tends to converge, and the slip amount convergence control flag F _{S is set} to “ After the state is set to "1", the process proceeds to step S24. In step S24, the peak value _{SP (n-1)} of the driving wheel slip amount updated and stored in the storage device 84d is cleared to "0", and the process proceeds to step S23.

[0068] At step S23, the slip amount convergence control flag F _S is determined whether the set state of "1", the slip convergence control flag F _S is "1"
If it is in the set state, the process proceeds to step S25,
If not, the process proceeds to step S26. In the step S25, the fluid coupling area control flag F _T is determined whether the set state of "1", when the fluid coupling area control flag F _T is in the set state of "1" Shifts to step S27, and if not, shifts to step S26.

[0069] In the step S27, since the slip convergence control flag F _S is in the set state of "1" and a fluid coupling area control flag F _T is in the set state of "1", the feedback as described above in the sense that may start the throttle opening control by the control shifts from the set state of the feedback control flag F _C "1" to step S28.

On the other hand, in the step S26,
Amount convergence control flag F_SIs in the reset state of “0”.
Or fluid coupling area control flag F_TBut
Since it is in the reset state of “0”,
Yes, start throttle opening control by feedback control
The feedback control flag F _C
Is reset to “0” and then the step S28 is performed.
Move to

In step S28, the engine speed Ne and the automatic transmission gear ratio i from the automatic transmission control unit 34 are read. Next, the process proceeds to step S29.
The current value S _{(n) of the} drive wheel slip amount is equal to the predetermined value S _0.
It is determined whether or not the current value S _{(n) of the} drive wheel slip amount is larger than the predetermined value S _0. If not, the process proceeds to step S30.
Move to

In step S30, it is determined whether or not the change amount α of the slip amount is smaller than the predetermined value α _0. If the change amount α of the slip amount is smaller than the predetermined value α ₀ , the process proceeds to step S30. The process proceeds to S32, and if not, the process proceeds to step S31. Step S32
In, which satisfies the respective processing steps of the step S29 and S30, the feed is determined that the forward control is to be performed a throttle opening control according to the set state of the feed forward control flag F _F "1" Then, the process proceeds to step S33.

At the step S33, at the step S33
Longitudinal acceleration detection value X read in 1 _G, Lateral acceleration detection value
Y_GAnd the gear ratio i read in step S28.
And the present value Tf of the driving torque according to the above equation (5)._(n)To
After the calculation, the process moves to step S34. The steps
In S34, the drive torque calculated in step S33 is calculated.
Current value Tf_(n)Is the current value T of the target drive torque.^* _(n)
Then, the process proceeds to step S35.

[0074] On the other hand, in step S31, feedback control flag F _C is determined whether the set state of "1", the step in the case where the feedback control flag F _C is set state of "1" The process moves to S36, and if not, the process moves to step S37.
In the step S36, it is determined whether or not the current value S _{(n) of the} drive wheel slip amount is larger than a predetermined positive value S ₁ which is a small positive value that is set to be almost zero. If the current value S _(n) is larger than the predetermined value S _{1, the} flow shifts to step S38; otherwise, the flow shifts to step S39.

In step S39, it is determined whether or not the change amount α of the slip amount is larger than a predetermined small value α ₁ which is a small positive value close to substantially zero. If the value S _(n) is larger than the predetermined value α ₁ , the process shifts to step S38; otherwise, the process shifts to step S40. In step S38, the average front wheel speed V _F calculated in step S4 and the longitudinal acceleration detection value X _G read in step S1,
Using the detected lateral acceleration value Y _G , the target slip amount S ^* is calculated in accordance with the above-described equation (6 ⁾ , and the process proceeds to step S41.

At the step S41, at the step S41
Target slip amount S calculated in step 38 ^*And drive wheel pick-up
Current value S_(n), And read in step S6
Previous value S of the detected drive wheel slip amount_(n-1)Using
The present value ΔT of the amount of increase / decrease of the driving torque of the engine according to equation (7)
_(n)Then, the process proceeds to step S42. The above
In step S42, the drive calculated in step S41 is determined.
Current value ΔT of dynamic torque increase / decrease_(n)And update memorized
Previous value T of the target drive torque of the engine ^* _(n-1)Using
Therefore, the present value T of the target drive torque is calculated according to the above equation (8).^* _(n)
Then, the process proceeds to step S35.

At the step S35, at the step S35
Using the current value T ^* _{(n) of} the target drive torque calculated in step S42 or step S42 and the current engine rotational speed Ne _(n) read in step S28, the target throttle opening degree is calculated in accordance with equation ₍ 9 ₎ . After calculating the current value θ ^* _(n) , the process proceeds to step S43. On the other hand, in the step S37, the feedforward control flag F _F is determined whether the reset state of "0", the when the feedforward control flag F _F is reset to "0" The process proceeds to step S40, and if not, the process proceeds to step S44.

In step S40, for example, in steps S36 and S39, the drive wheel slip amount S converges to some extent and the change amount α also converges, and the rear wheels 10
RL, wheel speed Vw _RL of 10RR, as such if Vw _RR is stable, it is determined that there is no any throttle opening control is also to be performed, the reset state of the feedback control flag F _C "0" And then step S4
5 and the feedforward control flag F _F
Is reset to "0", and the process proceeds to step S46 to set the current value θ ^* _(n) of the target throttle opening to "0", and then proceeds to step S43.

On the other hand, in step S44, the
Maintains throttle opening control amount by feedforward control
And the target throttle opening this time θ
^* _{(n )}Is the eye updated and stored in the storage device 84d.
Previous value of target throttle opening θ ^* _(n-1), Then
The process moves to step S43. In the above step S43
Is the target calculated or set in each of the arithmetic processing steps.
Current value T of drive torque^* _(n)， Target throttle opening now
Round value θ^* _(n), The current value S of the drive wheel slip amount_(n)The husband
Each time, the previous value was replaced with the subscript (n-1).
The updated data is stored in the storage device 84d.

Next, the routine proceeds to step S47, where the present value θ ^* _{(n) of the} target throttle opening is compared with the detected throttle opening, and if both are equal, the program returns to the main program, and If it is larger, the process proceeds to step S48. If the latter is larger, the process proceeds to step S49.
In step S48, a forward rotation signal is output to the step motor 45 in order to increase the throttle opening in the closing direction of the sub throttle valve 44, and then the process returns to the main program.

On the other hand, in step S49, a reverse rotation signal is output to the step motor 45 in order to reduce the throttle opening in the closing direction of the sub throttle valve 44, and then the program returns to the main program. Now, the operation of the throttle opening control by this arithmetic processing will be described with reference to the time chart of FIG.

This time chart assumes a state in which a stopped vehicle has suddenly started on a so-called low μ road surface. FIG. 7A shows the change over time of the drive wheel slip amount S of the rear wheels 10RL and 10RR as drive wheels, and FIG. 7B shows the change over time of the input / output shaft rotation speed ratio N and the input / output shaft torque ratio T of the torque converter 18. FIG.
Of the throttle opening TH in the closing direction (here, there is no delay with respect to the target throttle opening θ ^* , and it is assumed that both are equivalent). It should be noted that the input / output shaft rotational speed ratio N and the input / output shaft torque ratio T of the torque converter 18 are considered to be in a relationship obtained by multiplying the inverse ratio by a scalar (substantially a linear relationship from the relationship of the efficiency η). And there is a so-called hysteresis), while the input / output shaft rotational speed ratio N can be increased or decreased between “0” and “1”, whereas the input / output shaft torque ratio T is changed from “1” to T _MAX.
It can be increased or decreased up to. Also, the control curves of the throttle opening control by the arithmetic processing of the present embodiment are represented by solid lines, and the conventional control curves of executing the throttle opening control by the feedback control immediately after the execution of the throttle opening control by the feedforward control, respectively. Virtual line and subscript P
Is shown. Further, it is assumed that the control response time of the engine output to the throttle opening control by the feedforward control and the control response time of the engine output to the throttle opening control by the feedback control are equal or almost equal in each control. The predetermined value S ₂ is set to a positive value larger than the predetermined value S _0.

First, at time t when the vehicle is stopped₀₁Before
Indicates that the shift position is in the so-called N range,
For each sampling time during which the calculation processing of FIG.
Each wheel speed detection value Vw read in step S2_jIs
Since it is zero or almost zero, the average calculated in step S3
Rear wheel speed V_RIs also the average front wheel speed V calculated in step S4.
_FIs also zero or substantially zero, and the drive calculated in step S5
Current value S of wheel slip amount _(n)Is also read in step S6
Previous value S of the driving wheel slip amount_(n-1)Also zero or almost zero
And the change amount α of the slip amount calculated in step S7.
Also becomes zero or almost zero. On the other hand, the
The shift position is in the N range for each sampling time.
As a result, there is no gear engagement in the automatic transmission, and
The input and output shafts 18i and 18o of the Luc converter 18 are mutually
Impeller 18b and turbine
It rotates at a constant speed by direct rotation with the inner 18a.
The input / output shaft rotation speed ratio N becomes “1” or approximately “1”.
You. Therefore, the input / output shaft rotation speed ratio N is equal to the predetermined value.
N₀Larger, and therefore step S10 of the same arithmetic processing
To step S11, where the fluid coupling area
Range control flag F_TIs set to "1". But
From the current value S of the drive wheel slip amount_(n)Is still the place
Fixed value S₀Is smaller than the
Step S13 to Step S13 for each sampling time
15 and the peak control flag F_PIs the reset of “0”
In the step S20, the slip state is maintained.
Amount convergence control flag F_SIs held in the reset state of “0”
As a result, the same step S23 or step S25 is performed.
Then, the process proceeds to step S26, where the feedback control flag is set.
F_CAre held in the reset state of “0”. Also,
For each sampling time when the arithmetic processing of
Step S29 after Step S29 or Step S30
, But the feedback control flag F_CIs still
Since the reset state is "0", the process proceeds to step S37.
The feed forward control flag F_FIs still “0”
To step S40 because of the reset state of
Next, at steps S45 and S46, each control flag F_C, F
_FOpen target throttle while resetting to "0"
The current value of degrees θ^* _(n)Is set to “0”. Therefore,
Achieved in steps S47 to S49 via step S43
Throttle in the closing direction of the sub-throttle valve 44
The opening detection value TH is held at zero, and the so-called fully opened state is maintained.
It is. Here, the accelerator pedal 46 must be depressed.
For example, the rotation speed Ne of the engine 20 is a so-called idle rotation.
It will be maintained in state.

Next, in the case of the stopped vehicle, the time t₀₁
Shifts the shift position to the D range effective for normal driving
When the accelerator pedal 46 is suddenly depressed,
After that, the stepping amount is kept constant
Was. This time t₀₁From the rear wheels 10RL and 10
RR rapidly increases its wheel speed Vw_RL, Vw_RRIncrease
, Front wheels 10FL and 10F of the driven wheels equivalent to the vehicle speed
R wheel speed Vw_FL, Vw _FRDoes not increase or increases so much
As a result, the sump in which the arithmetic processing of FIG.
The drive wheel calculated in step S5 for each ring time
The slip amount S increased rapidly. At this time, drive wheels
Wheel speed Vw of the rear wheels 10RL and 10RR_RL, Vw_RR
Of the torque converter 18
Rotation speed detection value N of force shaft 18i_inOnly grows sharply
Therefore, the sampling at which the same arithmetic processing is executed
The input / output axis calculated in step S9 for each time
The rotation speed ratio N suddenly decreases, and the input / output
The shaft torque ratio T will increase sharply.

Eventually, the sampling process of the arithmetic processing of FIG.
The drive wheel slip calculated in step S5 for each
Amount S is calculated at time t₀₂And the predetermined value S₀Beyond. At this time
Time t ₀₁From time t₀₂Time until the input / output shaft rotation speed
The ratio N is relatively large and the predetermined value N₀Time greater than
t₀₁Immediately after the sampling, the sump in which the arithmetic processing of FIG.
The process moves from step S10 to step S11 for each ring time.
To the fluid coupling area control flag F_TBut
Set to "1". However, the drive wheel slot
Current value S_(n)Is still the predetermined value S₀Less than
Therefore, every sampling time when the same arithmetic processing is executed
Then, the process proceeds from step S13 to step 15, and
Peak control flag F_PIs held in the reset state of “0”
In step S20, the slip amount convergence control flag is set.
F_SAre held in the reset state of “0”,
After step S23 or step S25, step S2
6 and the feedback control flag F_CIs “0”
It is kept in the reset state. Also, this calculation process is executed
For each sampling time performed, step S29 or
After step S30, the process proceeds to step S31.
Feedback control flag F_CIs still "0" reset status
The process proceeds to step S37 because the
Word control flag F_FIs still in the reset state of “0”.
To step S40, and then to step S4
5, each control flag F in S46_C, F_FIs reset to “0”.
The current value of the target throttle opening degree θ^* _(n)
Is set to “0”. Therefore, after step S43
Sub-throttle bar achieved in steps S47 to S49
The throttle opening detection value TH in the closing direction of the lube 44 is zero.
And a so-called fully open state is maintained. Here,
Depending on the depression amount of the cell pedal 46 (substantially the corresponding
(With a response delay), the rotational speed Ne of the engine 20 increases.
Add. Also, in step S10 of the arithmetic processing of FIG.
The input / output shaft rotation speed ratio N is equal to the predetermined value N.₀Time when
Thereafter, in step S12, the fluid coupling area
Control flag F_TIs kept in the reset state of “0”
Is the flow of other arithmetic processing the same as above?
The slot in the closing direction of the sub throttle valve 44
The opening detection value TH is maintained at zero, and the so-called fully open state is maintained.
In accordance with the depression amount of the accelerator pedal 46 (substantially
With a corresponding response delay), the rotational speed of the engine 20
The degree Ne increases.

However, the driving wheel slip amount S calculated in step S5 of the calculation processing of FIG. 6 is equal to the predetermined value S _0.
Since the input / output shaft rotation speed ratio N is still less than or equal to the predetermined value N _{0 in} the first calculation process after time t ₀₂ that exceeds
Fluid coupling area control flag F _T is maintained at "0", since the driving wheel slippage S as described above is larger than the predetermined value S _0, yet shifts from the step S13 to step S14 " The driving wheel slip amount peak value _{SP (n-1)} set to "0" is read, and then the process proceeds to step S16, where the driving wheel slip amount peak value _{SP (n)} which is still "0" is read. _-1) than, proceeds to step S17 to the drive wheel slip amount of the current value S _(n) is large, the peak value S _P output current value S _(n) a drive wheel slip amount of the driven wheel slip amount _It is updated and stored in the storage device 84d as _(n-1) . Then, step S1 of the current calculation process
Peak control flag F _P 5 is held in the reset state of "0", also slip convergence control flag F _S at the step S20 is held in the reset state of "0", resulting in the step S23 or step S25 the process proceeds to step S26 via a feedback control flag F _C is held in the reset state of "0". On the other hand, in the current calculation process, the current value S _(n) of the drive wheel slip amount is larger than the predetermined value S ₀ , and the change amount α of the slip amount calculated in step S7 is the negative value of the negative value. Assuming that it is smaller than the predetermined value α ₀ , that is, assuming that the current value S _(n) of the drive wheel slip amount is increasing at a sufficiently increased speed, the process proceeds from step S29 to step S32 via step S30. and, the set state of the feedforward control flag F _F "1", then step S33
And the current value Tf _{(n ) of} the drive torque according to the current gear ratio i, the longitudinal acceleration detection value X _G , and the lateral acceleration detection value Y _G
Is calculated, and the current value Tf _(n) of the drive torque is set to the current value T ^* _(n) of the target drive torque in step 34, and then the process proceeds to step S35 to calculate the current value T ^{* of the} target drive torque ^. _(n) and the current engine speed Ne
present value of the target throttle opening based on _{(n) θ} ^* _(n) is calculated. At this time, since the rotational drive torque of the engine which is evaluated as being excessive should be reduced, the current value θ ^* _(n) of the target throttle opening is set to the sub-throttle valve 44.
Should be positive to control in the closing direction,
Accordingly, in steps S47 to S49 of the current arithmetic processing, the throttle opening detection value TH in the closing direction of the sub-throttle valve 44 increases in the positive direction, and the throttle opening in the closing direction of the sub-throttle valve 44 and the throttle opening Depending on the amount of depression of the pedal 46 (substantially with a corresponding response delay), the rotational speed Ne of the engine 20 tends to continue to increase while decreasing its increasing slope.

In general, the sub-throttle valve 4
When the throttle opening control in the closing direction of 4 is executed,
As described above, there is a substantial response delay, so
The rotational driving force of the gin 20 increases while decreasing its increasing slope.
And the rear wheels 10RL and 1
Wheel speed detection value Vw of 0RR_RL, Vw_RRAlso increase its slope
Attempts to keep increasing while decreasing. Therefore, the previous figure
6 is a sampler in which the arithmetic processing is executed after the arithmetic processing
For each driving time, the driving wheel slip calculated in step S5 is performed.
Current value S of lip amount_(n)Still maintains an increasing trend,
The change amount α of the slip amount calculated in step S7 is as follows.
First, the slip amount change α
Value α₀Assuming that this is the case,
The input / output shaft rotation speed that continues to decrease in accordance with the amount of lip
The ratio N is still a predetermined value N₀Step S10
Then, the process proceeds to step S12, where the fluid coupling is performed.
Area control flag F_TIs maintained at “0”,
As described above, the drive wheel slip amount S is equal to the predetermined value S.₀Greater than
Therefore, the process goes from step S13 to step S14.
The driving wheel slip that was updated and stored during the previous calculation
Peak value of quantity S_{P (n- 1)}Is read, and then step S1
6 and the peak value S of the drive wheel slip amount_{P (n-1)}
Value of the continuously increasing drive wheel slip amount S
_(n)Is large, the process proceeds to step S17,
Current value S of wheel slip amount_(n)The drive wheel slip amount of peak
Value S_{P (n-1)}Is updated and stored in the storage device 84d. So
Then, at the time of sampling when the arithmetic processing after this time is executed
Every time the peak control flag F is set in step S15._PIs
It is held in the reset state of “0”, and in the same step S2
At 0, the slip amount convergence control flag F_SIs reset to “0”
In the step S23 or the step
The process proceeds to step S26 via
Control flag F_CIs held in the reset state of “0”
You. On the other hand, sampling
The present value S of the drive wheel slip amount for each_(n)Is before
The predetermined value S₀And calculated in step S7.
The change amount α of the issued slip amount is the negative predetermined value α₀Less than
Since it is assumed that the above is
The process proceeds to step S31 through step S30, and
Feedback control flag F_CIs in the reset state of “0”
Then, the process proceeds to step S37, and the time t₀₂Immediately after
Feed forward control flag F_FIs “1”
Since it is in the set state, the process proceeds to step S44,
The previous value of the target throttle opening that is updated and stored here
θ^* _(n-1)Target throttle opening this time θ^* _{(n )}Is set
Time t₀₂Target slot equivalent to immediately after
Angle θ ^* _(n)Sets the sub throttle valve 44
Should be a positive value to control in the closing direction
The sampling time during which the calculation processing is performed
In each of the steps S47 to S49, the sub throttle
The throttle opening detection value TH in the closing direction of the valve 44 is
This sub-throttle is maintained in the increased state in the positive direction.
Throttle opening and accelerator in the closing direction of the valve 44
Depending on the amount of depression of the pedal 46 (essentially a corresponding response
The rotation speed Ne of the engine 20 is low.
Both increase slopes will decrease. This allows
Feed forward according to the vehicle behavior calculated by equation (5)
Engine drive torque Tf that enables
The engine drive torque Tf
Enables start acceleration or running stability according to the road surface μ
, The rear wheels 10RL, 10
RR wheel speed Vw_RL, Vw_RRGradually decreases, so the figure
6 for each sampling time during which the arithmetic processing of step 6 is executed.
The current value S of the drive wheel slip amount calculated in step S6
_(n)Continues to increase while decreasing its slope
Eventually, the slope becomes a decreasing slope and starts decreasing.
It will be. Naturally, the value calculated in step S7 is calculated.
The change amount α of the slip amount gradually becomes an absolute value in the negative region.
The absolute value gradually increases in the positive area,
It will be getting better. Therefore, the time t₀₂Since then, books
In the driving force control device of the embodiment, as shown in FIG.
By throttle opening control by feed forward control
Therefore, the throttle opening detection value TH (or the target throttle
Torque opening θ^*) Indicates the throttle opening TH corresponding to the road surface μ.
_RF(Or target throttle opening θ according to road μ)^* _RFNii
Will be held.

At each sampling time after the time t _{02 when} the arithmetic processing of FIG.
If it is determined at 0 that the change amount α of the slip amount is smaller than the negative predetermined value α ₀ , the throttle opening control by the feedforward control is executed again, but this is the drive wheel. This _{means that} the current value S _(n) of the slip amount of the rear wheels 10RL and 10RR has not sufficiently decreased the increase speed with respect to the previous value S _(n-1) . This means that the opening degree control of the sub-throttle valve 44 should be executed in accordance with this, and that the throttle opening degree control by the feedforward control, that is, the original purpose of the driving force control is achieved. Conceivable.

According to the conventional driving force control device,
Time t₀₂Immediately after the feed
Immediately after feedback control,
Throttle opening control is started.
Of throttle opening control by feedback control
The current value S of the driving wheel slip amount which is the controlling factor_(n)Wear only
At first glance, it is still going to increase,
The throttle opening control by feedback control
Throttle opening detection value TH of throttle valve 44 _P(Or
Target throttle opening θ^* _(n)) Increases further in the closing direction
Will continue. The throttle of this sub throttle valve 44
The throttle opening detection value TH_P(Or target throttle opening θ^*
_(n)The changes over time and their effects will be explained later.
I do.

The time t₀₂At the time of subsequent sampling
The slot operation is performed by the arithmetic processing shown in FIG.
The throttle opening detection value TH (or the target throttle opening θ^*)
Is the throttle opening TH according to the road surface μ._RF(Or road surface μ
Target throttle opening θ according to ^* _RFAnd continued to be
Then, as described above, the rear wheels 10RL, 10
RR wheel speed Vw_RL, Vw_RRGradually decreases, so the figure
6 for each sampling time during which the arithmetic processing of step 6 is executed.
The current value S of the drive wheel slip amount calculated in step S6
_(n)Eventually, the slope starts decreasing as the slope decreases
The slip calculated in step S7.
The amount of change α of the loop amount gradually increases in the positive region.
It will be good. Accordingly, the steps of the arithmetic processing of FIG.
Input / output shaft rotation of torque converter 18 calculated in S9
The speed ratio N is also the present value S of the drive wheel slip amount._(n)Reduction
Before and after the small start, the time begins to increase and is the inverse ratio
The input / output shaft torque ratio will begin to decrease. here,
The present value S of the drive wheel slip amount_(n)Began to decrease,
Peak value S_{P (n-1)}Deviation from the α_TwoSmaller and cheaper
But the current value S of the drive wheel slip amount_(n)Is not
The predetermined value S_TwoLarger than the input and output shaft rotation
The speed ratio N is still the predetermined value N₀Assumed smaller than
I do. Here, when the arithmetic processing of FIG.
The process moves from step S10 to step S12, and
Coupling area control flag F_TIs maintained at “0”
However, as described above, the drive wheel slip amount S is equal to the predetermined value S.
₀Because it is larger, steps S13 to S
14 and updates the drive updated and stored during the previous arithmetic processing.
Peak value S of wheel slip amount_{P (n-1)}Is read, then
The process proceeds to step S16 to determine the peak value of the drive wheel slip amount.
Value S_{P (n-1)}Than the drive wheel slip began to decrease
The current value S of the quantity_(n)Moves to step S18 because is small.
The current value S of the drive wheel slip amount_(n)And the drive wheel
Slip amount peak value S_{P (n-1)}Deviation from the positive predetermined
Value α_TwoTo step S19, and
Work control flag F_PIs changed to the set state of "1"
Is the current value S of the drive wheel slip amount in the next step S21.
_(n)Is still the predetermined value S_TwoIs larger than
In step S20, the slip amount convergence control flag F_SIs “0”
Is held in the reset state, and as a result,
Alternatively, the process proceeds to step S26 via step S25, and
Feedback control flag F_CIs reset to “0”
Will be retained. On the other hand, in this calculation process,
Current value S_(n)Is the predetermined value S₀Greater than
Also, the change amount of the slip amount calculated in step S7
α is the negative predetermined value α₀Because it should be more than
From step S29 to step S30 through step S30
31 and the feedback control flag F_CIs
Since the reset state is "0", the process proceeds to step S37.
And the feedforward control flag F_FIs still
Since it is in the set state of “1”, go to step S44
The target throttle opening is shifted and updated here
Previous value of^* _(n-1)Target throttle opening this time θ^*
_(n)Are continuously set, and accordingly, the above steps S47 to S4
9, the throttle by the feedforward control is used.
The throttle opening detection value TH equivalent to the opening control is maintained.
Subsequently, the sun where the arithmetic processing of FIG.
The same flow as above is repeated for each pulling time
That is, the rear wheels 10RL, 10
RR wheel speed Vw_RL, Vw_RRDrive wheel
Current value S of lip amount_(n)Continue to decrease,
Degree ratio N continues to increase, input / output shaft torque ratio T continues to decrease
The throttle opening detection value TH in the closing direction is
Throttle opening TH according to μ_RFWill continue to be maintained.

Next, the rear wheels 10RL, 10 which continue to decrease
RR wheel speed Vw_RL, Vw_RRAt time t in FIG.₀₃
Is the current value S of the driving wheel slip amount._(n)Is the predetermined value S
_TwoSmaller, but the input / output shaft rotation speed ratio N is
Still the predetermined value N₀It is assumed that it is smaller than. here
When the arithmetic processing of FIG. 6 is executed,
From 0, the process proceeds to step S12, where fluid coupling is performed.
Area control flag F _TIs maintained at "0",
The drive wheel slip amount S is equal to the predetermined value S₀Bigger
Read from step S13 to step S14
The peak value S of the drive wheel slip amount_{P (n-1)}Less than
Value S of the drive wheel slip amount that continues_{(n )}Is small
Peak at step S19 after steps S16 and S18
Control flag F_PContinues to be set to “1” and the next
In step S21, the current value S of the drive wheel slip amount_(n)Is
The predetermined value S_TwoIs smaller than that in step S22.
Then, the slip amount convergence control flag F_SIs set to “1”
And the driving wheel slip amount is determined in step S24.
Peak value S_{P (n-1)}Is reset to “0”, and
Although the process proceeds from step S23 to step S25,
Fluid coupling area control flag F_TIs still “0”
Is in the reset state, so that step S26 is consequently performed.
Shift to feedback control flag F_CIs the reset of “0”
It is kept in the reset state. On the other hand, in this calculation processing,
Current value S of drive wheel slip amount_(n)Is still the predetermined value S₀
Is larger than the slip calculated in step S7.
The change amount α of the tip amount is the negative predetermined value α₀Should be more than
Therefore, steps S29 to S30 are required.
After that, the process proceeds to step S31 and the feedback system is still in effect.
Your flag F_CIs in the reset state of “0”,
The control proceeds to step S37, where the feed forward control flag is set.
F_FIs still in the set state of “1”.
The process proceeds to step S44, where the target slot
Previous value of the throttle opening θ^* _(n-1)Of the target throttle opening
This time θ^* _(n)Continue to be set, so that the step S
In steps 47 to S49, the feedforward control
Throttle opening detection value TH equivalent to throttle opening control
Is maintained, and thereafter, the arithmetic processing of FIG.
The same flow as above is repeated for each sampling time
The rear wheels 10 which are the driving wheels
Wheel speed Vw of RL, 10RR _RL, Vw_RRWith the decrease
And the current value S of the drive wheel slip amount_(n)Continues to decrease and
The output shaft rotation speed ratio N continues to increase, and the input / output shaft torque ratio T
Continues to decrease, and the throttle opening detection value TH in the closing direction TH
Is the throttle opening TH corresponding to the road surface μ._RFMaintained in
to continue.

Next, the rear wheels 10RL, 10 which continue to decrease
RR wheel speed Vw_RL, Vw_RRAt time t in FIG.₀₄
Is the current value S of the driving wheel slip amount._(n)Is the predetermined value S
_TwoAnd the input / output shaft rotation speed ratio N
Predetermined value N₀It is assumed that it becomes larger than. here
When the arithmetic processing of FIG. 6 is executed,
From step 0 to step S11,
Area control flag F_TChanges to the set state of “1”.
However, as described above, the drive wheel slip amount S is equal to the predetermined value.
S₀Step S13
The peak value S of the drive wheel slip amount read in S14
_{P (n-1)}The current value S of the drive wheel slip amount that continues to decrease
_(n)Is small, the process proceeds through steps S16 and S18.
In step S19, the peak control flag F_PIs set to “1”
, And in the next step S21, the drive wheel slip amount
This time value S_(n)Is the predetermined value S_TwoIs smaller than
In step S22, the slip amount convergence control flag F_SBut
The state is changed to the set state of “1”, and further in step S24
Peak value S of drive wheel slip amount_{P (n-1)}To “0”
Therefore, the process goes from step S23 to step S25.
After the transition, the fluid coupling area control flag F_T
Is set to “1”.
Proceeding to step S27, the feedback control flag F_C
Is changed to the set state of “1”. And this performance
In the calculation process, the current value S of the drive wheel slip amount is calculated. _(n)Is still
The predetermined value S₀And in step S7
The change amount α of the calculated slip amount is the negative predetermined value α.₀
Since it should be more than above, the process proceeds from step S29.
After step S30, the process proceeds to step S31,
Feedback control flag F_CIs set to “1”
Then, the process proceeds to step S36, where the drive wheel slip amount is
Round value S_(n)Is still a very small positive value S₁Than
Shift to steps S38, S41 and S42
And the target slip amount S^*, The current value of drive torque increase / decrease Δ
T_(n), The current value T of the target drive torque^* _(n)Are calculated respectively.
Then, the process proceeds to step S35, where the target drive torque
This time value T^* _(n)And the current engine speed Ne_(n)To
Current value θ of the target throttle opening based on^* _{(n )}Is calculated
Therefore, in steps S47 to S49, the filter
The throttle opening control by feedback control is executed,
After that, the sampling process in which the arithmetic processing of FIG.
The same flow as above is repeated for each
Therefore, the rear wheels 10RL and 10RR that are the drive wheels
Wheel speed Vw_RL, Vw_RROf the driving wheel slip amount
This time value S_(n)Feedback control according to changes in
The throttle opening control is started, and the road surface μ
Unless it changes, the throttle opening detection value T in the closing direction
H is the throttle opening TH corresponding to the road surface μ._RFIn the vicinity
Will be transferred. Actually, this time of the drive wheel slip amount
Value S_(n)Is considered to be stable on the road surface.
Overshoot occurred below the
In response to this overshoot, the throttle opening detection value T
H is a throttle opening TH corresponding to the road surface μ._RFMore
And then decreased, but then increased again
Throttle opening TH according to road surface μ_RFAsymptotically.

During this time, the input / output shaft rotational speed ratio N of the torque converter 18 continues to increase smoothly, and the input / output shaft torque ratio T also keeps decreasing smoothly. Therefore, when the vehicle starts and accelerates substantially, The feeling of acceleration felt by the driver will be stable, and at the same time, the vehicle will be able to realize stable starting acceleration. Of course, the rear wheel 10 which is the driving wheel
Since the slips of the RL and 10RR are converged in a relatively short time by the throttle opening control by the feedforward control, the running stability is not impaired when the vehicle starts and accelerates.

[0094] On the other hand, the conventional throttle opening detection value TH _P which moves to the throttle opening control by the feedback control immediately after the throttle opening control by the feed forward control as described above, the slip of the further drive wheels as described above The increase is controlled in the closing direction in accordance with the amount S. As a result, the rotational driving force of the engine is greatly reduced (it is considered that the rotational speed Ne is also reduced at the same time).
Reduction of the driving wheel slippage S _P, as shown in the earlier. However, as a result, the input / output shaft rotational speed ratio N _{P of} the torque converter also rapidly increases, and at the same time, the input / output shaft torque ratio T _P rapidly decreases. The operating region of the torque converter in the converter region is forcibly shifted to or in the direction of the fluid coupling region. However, on the other hand, since the rotational driving force of the engine has also been greatly reduced, the drive wheels cannot be sufficiently rotated in this fluid coupling region, that is, in the directly connected state or almost directly connected state, for example, as shown in FIG. 7A. fall to substantially zero driving wheel slippage S _P as, i.e. simply because a state that merely by coasting or inertial running, the driver poor acceleration feeling can be felt as a feeling of deceleration in the reverse.

In the driving force control calculation process of this embodiment, the vehicle shifts to a stable steady running state on, for example, a high μ road surface. As a result, the present value S _{(n) of the} driving wheel slip amount is extremely small. becomes smaller than the predetermined values S ₁ a small positive value, steps simultaneously the amount of change alpha is smaller than the predetermined value alpha ₁ for the very small positive value, through steps S36, S39 of the arithmetic processing of FIG. 6 In steps S40 and S45, the control flags F _C and F _F are reset to “0”. Then, in step S46, the current value θ ^* _(n) of the target throttle opening is set to “0”, and The throttle valve 44 is returned to the fully open state, and the control is shifted to the control for maximizing the rotational driving force of the engine 20 according to the amount of depression of the accelerator pedal 46.

As described above, this embodiment corresponds to claim 1 of the present invention.
It is considered that the driving force control device according to FIGS.
S7 corresponds to the driving wheel slip state detecting means of the driving force control device according to claims 1 and 2 of the present invention, and similarly, steps S8 to S12 of the calculation processing in FIG. Step S33 of the calculation processing of FIG.
S34 corresponds to the first output reduction amount calculating means, and steps S38, S41, and S42 of the calculation processing of FIG. 6 correspond to the second output reduction amount calculation means, and step S13 of the calculation processing of FIG.
To SS31, S36, S37, and S39 correspond to the selection means, and the other calculation processing steps of the calculation processing in FIG. 6 correspond to the engine output adjustment means.

In the above-described embodiment, the operating range of the torque converter is determined from the speed ratio. However, the present invention is not limited to this. The operating range is determined based on the torque ratio transmission efficiency or the presence or absence of rotation of the stator. Is also good. Next, a second embodiment of the driving force control device of the present invention will be described. FIG.
FIG. 3 is a schematic configuration diagram showing a second embodiment of the present invention, and the basic configuration of the vehicle is the same or almost the same as that of FIG. 2 showing the first embodiment. Omit. The basic configuration of the engine 20, the main throttle valve 48, and the sub-throttle valve 44, and the configuration and operation of the sensors 42 and 47 are the same or almost the same as those in FIG. 2 showing the first embodiment. A detailed description is omitted.

The basic structure of the torque converter 18 and the automatic transmission 14 and the structure and operation of the automatic transmission control device 34 and the actuator unit 32 are also the same as those of the first embodiment.
Since it is the same or almost the same as that of FIG. 2 showing the embodiment, the detailed description is omitted. However, in this embodiment, the input shaft 18i of the torque converter 18 has an input shaft torque sensor 38a instead of the input shaft rotation speed sensor 39a.
However, the output shaft 18o has an output shaft rotation speed sensor 39b.
Is provided an output shaft torque sensor 38b in place of, the voltage signal corresponding to the magnitude of the torque sensor 39a of the axial torque detected by 39b, respectively an input shaft torque detection value T _in and an output shaft torque is output to the controller 30 to be described later as a detection value T _{ou t.}

The hydraulic cylinders 52FL to 52RR provided on the wheels 10FL to 10RR and the traction control hydraulic pressure control valves 54L and 54L provided in the brake hydraulic system of the rear wheels 10RL and 10RR which are driving wheels are provided.
The configuration and operation of 54R and the like are the same or almost the same as those in FIG. 2 showing the first embodiment, and therefore detailed description thereof will be omitted.

As shown in FIGS. 8 and 9, a wheel speed sensor 28FL provided on each of the wheels 10FL to 10RR is provided.
The configuration and operation of the longitudinal acceleration sensor 40 and the lateral acceleration sensor 26 provided on the vehicle are the same or almost the same as those shown in FIGS. 2 and 3 showing the first embodiment. I omit the explanation. Further, as shown in FIGS. 8 and 9, the basic configuration of the controller 30 is the same as or substantially the same as that of the first embodiment shown in FIGS. 2 and 3, and therefore a detailed description thereof is omitted. . However, since the detected voltage signals from the input shaft torque sensor 38a and the output shaft torque sensor 38b do not need to be subjected to frequency-to-voltage conversion, there are no frequency-to-voltage converters 81a and 81b in FIG. The detection signal from 38b is directly converted into a digital signal by the A / D converters 83E and 83F, and is input via the input interface 84a of the microcomputer 84.

Here, as shown in FIG.
The basic configuration of the computer 84 and the microcomputer
Rear wheels 10RL, 10R, which are drive wheels executed by the
Hydraulic hydraulic pressure of R side wheel cylinders 52RL, 52RR
The structure and operation of (brake fluid pressure) control are the same as those of the first embodiment.
Is similar or almost similar to that of FIGS.
The detailed explanation is omitted. However, in this embodiment,
Engine executed by leverage microcomputer 84
The output reduction control, that is, the driving force control, is the same as that of the first embodiment.
Unlike this, the current state of the rear wheels 10RL and 10RR that are drive wheels is different.
Current slip amount S _(n)Is calculated or detected, and this current
Lip amount S_(n)Is a predetermined value S₀Before and after
Longitudinal acceleration detection value X from acceleration sensor 40_GAnd Yoko
Lateral acceleration detection value Y from speed sensor 26_GAnd the current self
Required engine 20 based on gear ratio i of dynamic transmission 14
Target output (target driving torque) T^* _(n)And calculate this
Target drive torque T^* _(n)And the engine speed Ne
Target throttle opening of the sub-throttle valve 44
θ^*And calculate the target throttle opening θ^*Achieve
A rotation drive signal is output to the step motor 45.
That do not respond only to the so-called slip condition of the drive wheels.
Start throttle opening control by feedforward control
Then, the longitudinal acceleration detection value X_GAnd lateral acceleration detection
Outgoing Y_GAnd average front wheel speed V equivalent to vehicle speed_FOn the basis of the
Target slip amount of rear wheels 10RL, 10RR that are drive wheels
S^*Calculated from the input shaft torque sensor 38a.
Luc converter input shaft torque detection value T_inAnd output shaft torque
Output shaft torque detection from the torque sensor 38b
Outgoing T_outOperating range of the torque converter 18 based on
And the torque amplification ratio is determined by the input / output shaft torque ratio.
T as the input / output shaft torque ratio T decreases.
Proportional control gain K_PAnd integral control gain K_ILarge
The target slip amount S^*And the current slip amount S
_(n)And the previous slip amount S_(n-1)Using this proportional control
Gain K_PAnd integral control gain K_IUsing the current
Gin drive torque increase / decrease ΔT_(n)Is calculated and this current
Engine drive torque increase / decrease ΔT_(n)And the previous target drive
Luc T^* _(n-1)Target driving torque T using^* _(n)Calculate
And the target drive torque T^* _(n)And engine speed
Target throttle of sub-throttle valve based on Ne
Opening θ^*And calculate the target throttle opening θ^*Achieve
Output to the stepping motor 45.
So-called feedback according to the so-called slip condition of the drive wheels
The throttle opening control by the lock control is started.

Next, the basic principle of the driving force control by the throttle opening control of the sub-throttle valve 44 executed in this embodiment will be described. As described above, when executing the throttle opening control by the feedforward control and the throttle opening control by the feedback control,
A particular problem is that immediately after the rotational driving force of the engine is reduced by the feedforward control, the throttle opening control by the feedback control further reduces the rotational driving force of the engine that has not been sufficiently reduced. This means that the torque amplifying action in the converter region of the torque converter is compensated. If so, the torque amplifying effect of the torque converter is detected, and the control amount of the throttle opening by the feedback control may be changed so as not to compensate for the torque amplifying effect. Specifically, the control gain of the feedback control system is changed according to the input / output shaft torque ratio T to cope with the problem. That is, when the output shaft torque ratio T is large is set smaller the proportional control gain K _P and integral control gain K _I, a smaller or compensation margin that does not compensate the torque amplifying action of the torque converter, input and output when the shaft torque ratio T is small is set larger the proportional control gain K _P and integral control gain K _I, may be improved the responsiveness of the driving force reduction control.

[0103] Here, the output shaft torque ratio T, a torque converter output shaft torque detection value T _out from the torque converter input shaft torque detection value T _in and an output shaft torque sensor 38b from the input shaft torque sensor 38a It is used to calculate according to the following equation (15). T = T _out / T _in (15) FIG. 11 shows a map of this. Among them, FIG. 11A is a control map of the proportional control gain K _P , in which the input / output shaft torque ratio T is a predetermined value T to some extent.
When it is ₁ or more, the proportional control gain K _P is maintained at a relatively small predetermined value K _P1 , and when the input / output shaft torque ratio T is “1” or less, the proportional control gain K _P becomes a relatively large predetermined value K _{P1. When} the input / output shaft torque ratio T is maintained at _P0 and is between “1” and the predetermined value T ₁ , the predetermined value K _{P0 is changed} to the predetermined value K _P1 according to the increase of the input / output shaft torque ratio T. Up to a value that decreases linearly. Moreover, Figure 11b is a control map of said integral control gain K _I, the input and output shafts torque ratio T is some degree higher predetermined value T ₁
The time is more than, integral control gain K _I is kept relatively small predetermined value K _I1, output shaft torque ratio T is "1"
When it is equal to or less than the predetermined value, the integral control gain K _I is maintained at a relatively large predetermined value K _I0 , and the input / output shaft torque ratio T becomes
Wherein when it is until the predetermined value T ₁ is set to a value that decreases linearly from the prescribed value K _I0 to the predetermined value K _I1 with an increase in the output shaft torque ratio T from.

Then, similarly to the above, the current value S _{(n) of the} drive wheel slip amount calculated by the formulas 10 to 12 is larger than the predetermined value S ₀ and the change of the slip amount calculated by the formula 13 When the amount α is smaller than a predetermined negative value α ₀ , the throttle opening control by the feedforward control is started, and immediately thereafter, the process shifts to the throttle opening control by the feedback control.

Next, an arithmetic process for executing the throttle opening control in the closing direction of the sub-throttle valve 44 based on the principle of the present invention will be described with reference to FIG. Each control flag F _C in the drawing, a feedback control flag enables the throttle opening controlled by the feedback control. This arithmetic processing is executed by a timer interrupt processing at a predetermined time ΔT of, for example, about 10 msec. In the arithmetic processing unit 84c of the microcomputer 84. First, in step S51, the longitudinal acceleration detection value X from the longitudinal acceleration sensor 40 is obtained. _G and the lateral acceleration detection value Y _G from the lateral acceleration sensor 26 are read.

Next, the flow shifts to step S52, where the wheel speed detection values Vw from the wheel speed sensors 28FL to 28RR are determined.
_j (j = FL to RR) is read. Next, the process proceeds to step S53, where the rear wheel 10R read in step S52 is read.
L, 10 _RR , using the wheel speeds Vw _RL , Vw _RR ,
Calculating an average rear wheel speed V _R in accordance with 0 equation.

Next, the flow shifts to step S54, using the wheel speeds Vw _FL , Vw _FR of the front wheels 10FL, 10FR read in step S52, an average front wheel speed V _F equivalent to the vehicle speed is calculated in accordance with the equation (11). calculate. Next, step S5
5 and the average rear wheel speed V _R calculated in step S53 and the average front wheel speed V _R calculated in step S54.
_{Using F} , the present value S _(n) of the drive wheel slip amount is calculated according to the above equation ₍ 12 ₎ .

Next, the flow shifts to step S56, where the previous value S _(n-1) of the drive wheel slip amount updated and stored in the storage device 84d in the previous calculation processing is read. Next, the process proceeds to step S57, using the current value S _(n) of the drive wheel slip amount calculated in step S55 and the previous value S _(n-1) of the drive wheel slip amount read in step S56. ,
The change amount α of the slip amount is calculated according to the above equation (13).

Next, the flow shifts to step S58, where the engine speed Ne and the automatic transmission gear ratio i from the automatic transmission control device 34 are read. Next, the routine proceeds to step S59, the said driving wheel slip amount of the current value S _(n) is determined whether greater than the predetermined value S _0, the current value S of the driving wheel slip amount _(n) is If it is larger than the predetermined value S ₀ , the process proceeds to step S60, otherwise, the process proceeds to step S61.

In step S60, it is determined whether or not the change amount α of the slip amount is smaller than the predetermined value α _0. If the change amount α of the slip amount is smaller than the predetermined value α ₀ , the process proceeds to step S60. The process proceeds to S62, and if not, the process proceeds to step S61. Step S62
After satisfying the calculation processing steps of steps S59 and S60 and executing the throttle opening control by the feedforward control, it is determined that the process should shift to the throttle opening control by the feedback control. the process proceeds to step S63 after the set state of the feedback control flag F _C "1".

In step S63, step S
Using the longitudinal acceleration detection value X _G and lateral acceleration detection value Y _G read at 51 and the gear ratio i read at step S58, the present value Tf _{(n) of the} driving torque according to the above equation ₍ 5 _).
Then, the process proceeds to step S64. In step S64, the current value Tf _(n) of the drive torque calculated in step S63 is changed to the current value T ^{* of the} target drive torque ^.
_After setting to _(n) , the process moves to step S65.

[0112] On the other hand, in step S61, feedback control flag F _C is determined whether the set state of "1", the step in the case where the feedback control flag F _C is set state of "1" The process moves to S66, and if not, the process moves to step S67.
In the step S66, it is determined whether or not the current value S _{(n) of the} drive wheel slip amount is larger than a predetermined value S _1, which is a small positive value that is nearly equal to a preset zero, and the drive wheel slip amount is determined. If the current value S _(n) is larger than the predetermined value S _{1, the process} proceeds to step S68; otherwise, the process proceeds to step S69.

In step S69, it is determined whether or not the change amount α of the slip amount is larger than a predetermined small value α ₁ which is a small positive value which is almost equal to zero. If the value S _(n) is larger than the predetermined value α ₁ , the process shifts to step S38; otherwise, the process shifts to step S67. Step S68
In the longitudinal acceleration detected value was read at an average front wheel speed V _F and the step S51 which is calculated in step S4 X
_{Using G} and the lateral acceleration detection value Y _G , the target slip amount S ^* is calculated in accordance with the above-described equation (6 ⁾ , and the process proceeds to step S70.

[0114] In the step S70, the from crowded reading the torque converter output shaft torque detection value T _out from the torque converter input shaft torque detection value T _in and an output shaft torque sensor 38b from the input shaft torque sensor 38a, the step S71 Transition. In the step S71, using the read written torque converter input shaft torque detection value T _in and the torque converter output shaft torque detection value T _out at the step S70, the after calculating the output shaft torque ratio T in accordance with the 15 formula , To step S72.

At step S72, at step S72
According to the input / output shaft torque ratio T calculated in step 71,
From each control map of FIG._PAnd integral system
Your gain K_IAfter setting search, move to step S73.
Run. In the step S73, the step S72
Proportional control gain K set by _PAnd integral control gain K
_I, The target slip amount S calculated in step S68
^*, And the current value S of the drive wheel slip amount_(n), And the above
Previous value S of the drive wheel slip amount read in step S56
_(n-1)And the driving torque of the engine according to the above equation (7).
Current value ΔT_(n)Is calculated, and then step S7
Move to 4.

At the step S74, at the step S74
The present value ΔT of the drive torque increase / decrease amount calculated in 71_(n)Passing
And the last stored target driving torque of the engine
Value T ^* _(n-1)And the target drive torque according to the above equation (8).
Current value T^* _(n)Is calculated, and then the step S65 is performed.
Move to In the step S65, the step S65
64 or the target drive torque calculated and set in step S74.
Current value T^* _(n)And read in step S58
Current engine speed Ne_(n)Using the above 9
The current value θ of the target throttle opening according to^* _(n)Is calculated
Then, the process proceeds to step S75.

On the other hand, in step S67, for example, in steps S66 and S69, the drive wheel slip amount S converges to some extent and the change amount α also converges, and the wheel speed Vw of the rear wheels 10RL and 10RR which are the drive wheels. _RL, as in such a case where Vw _RR is stable, it is determined that should not be performed any throttle opening control, and the reset state of the feedback control flag F _C "0", then proceeds to step S76 And the current value of the target throttle opening θ ^*
_{After (n)} is set to "0", the flow shifts to step S75.

In step S75, the current value T ^* _{(n) of} the target drive torque, the current value θ ^* _{(n) of the} target throttle opening, and the current value of the drive wheel slip amount calculated or set in each of the arithmetic processing steps. The value S _(n) is replaced with the previous value with the subscript replaced by (n-1) in the form of the storage device 84d.
And store the updated information. Next, the routine proceeds to step S77, where the present value θ ^* _{(n) of the} target throttle opening is compared with the throttle opening detection value, and if the two are equal, the process returns to the main program. Shifts to step S78, and if the latter is large, shifts to step S79.

In step S78, a normal rotation signal is output to the step motor 45 in order to increase the throttle opening in the closing direction of the sub throttle valve 44, and then the program returns to the main program. On the other hand, in step S79, the step motor 4
After outputting a reverse rotation signal toward 5, the program returns to the main program.

Now, the operation of the throttle opening control by this arithmetic processing will be described with reference to the time chart of FIG. This time chart assumes a state in which a stopped vehicle has suddenly started on a so-called low μ road surface. Then, rear wheels 10RL and 10RR which are drive wheels are shown in FIG.
FIG. 2B shows the change over time of the drive wheel slip amount S, FIG. 2B shows the change over time of the input / output shaft rotational speed ratio N and the input / output shaft torque ratio T of the torque converter 18, and FIG.
4 shows a temporal change of the throttle opening TH in the closing direction (here, there is no delay with respect to the target throttle opening θ ^* , and it is assumed that both are equivalent). It should be noted that the input / output shaft rotational speed ratio N and the input / output shaft torque ratio T of the torque converter 18 are considered to be in a relationship obtained by multiplying the inverse ratio by a scalar (substantially a linear relationship from the relationship of the efficiency η). And there is so-called hysteresis), while the input / output shaft rotation speed ratio N can be increased or decreased between “0” and “1”, whereas the input / output shaft torque ratio T is changed from “1” to T
_It can be increased or decreased up to _MAX . Further, the control curves of the throttle opening control by the arithmetic processing of the present embodiment are represented by solid lines, respectively. Are indicated by virtual lines and with a suffix P. Further, it is assumed that the control response time of the engine output to the throttle opening control by the feedforward control and the control response time of the engine output to the throttle opening control by the feedback control are equal or almost equal in each control. The predetermined value S ₂ is set to a positive value larger than the predetermined value S _0.

[0121] First, at time t ₂₁ before the vehicle is stopped, each wheel shift position as a so-called N-range, for each sampling time calculation process is performed in FIG. 10, which is read at the step S52 Speed detection value V
Since w _j is zero or substantially zero, the average rear wheel speed V _R calculated in step S53, the average front wheel speed V _F is also zero or substantially zero, which is calculated in step S54, is calculated in step S55 The current value S _{(n) of the} drive wheel slip amount is also the previous value S _{(n -1) of the} drive wheel slip amount read in step S56.
Is also zero or substantially zero, and the change amount α of the slip amount calculated in step S57 is also zero or substantially zero. Therefore, the process proceeds to step S61 via step S59 or step S60 for each sampling time at which this calculation process is executed, but the feedback control flag F _C is still “0”.
To step S67 because of the reset state of
The feedback control flag F _C maintains the reset state of "0", then the current value θ ^* _(n) of the target throttle opening degree in step S76 is set to "0". Therefore, the throttle opening detection value TH in the closing direction of the sub-throttle valve 44 achieved in steps S77 to S79 after step S75 is maintained at zero, and a so-called fully open state is maintained. Here, if the accelerator pedal 46 is not depressed, the rotation speed Ne of the engine 20 is maintained at that of a so-called idle rotation state.

Next, in the case of the stopped vehicle, the time t_{twenty one}
Shifts the shift position to the D range effective for normal driving
When the accelerator pedal 46 is suddenly depressed,
After that, the stepping amount is kept constant
Was. This time t_{twenty one}From the rear wheels 10RL and 10
RR rapidly increases its wheel speed Vw_RL, Vw_RRIncrease
, Front wheels 10FL and 10F of the driven wheels equivalent to the vehicle speed
R wheel speed Vw_FL, Vw _FRDoes not increase or increases so much
As a result, as a result, the sample in which the arithmetic processing of FIG.
The drive calculated in step S55 for each pulling time
The driving wheel slip amount S increased rapidly. Also, at this time
Wheel speed Vw of rear wheels 10RL, 10RR that are driving wheels_RL, V
w_RRWith the rapid increase of only the torque converter 18
Speed N of the input shaft 18i_inOnly increase rapidly
, The input / output shaft rotation speed ratio N sharply decreases.
However, the input / output shaft torque ratio T sharply increases.
Will do.

[0123] Eventually, the driving wheel slip amount S that is calculated for each calculation of the sampling time at the step S55 of FIG. 10, at time t ₂₂ exceeds the predetermined value S _0. Since the current value S _(n) of the drive wheel slip amount is still smaller than the predetermined value S ₀ during the time from the time t ₂₁ to the time t ₂₂ , each time the sampling process is performed,
Shifts from the step S59 to a step 61, the process proceeds to step S67 to feedback control flag F _C is reset state of still "0", while maintaining a feedback control flag F _C to the reset state of "0" , The current value θ ^* of the target throttle opening in step S76
_(n) is set to “0”. Accordingly, the throttle opening detection value TH in the closing direction of the sub-throttle valve 44 achieved in steps S77 to S79 after step S75.
Is maintained at zero, and a so-called fully open state is maintained. here,
The rotational speed Ne of the engine 20 depends on the depression amount of the accelerator pedal 46 (substantially with a corresponding response delay).
Increases.

However, the steps of the arithmetic processing shown in FIG.
The drive wheel slip amount S calculated in step S55 is equal to the predetermined value.
S₀Time t beyond_{twenty two}In the first subsequent operation,
The change amount α of the slip amount calculated in step S57 is
The predetermined value α of the negative value₀Assuming it is smaller,
The current value S of the drive wheel slip amount with a sufficient increase speed_{(n )}
Assuming that is increasing, from step S59
After step S60, the process proceeds to step S62, and the
Feedback control flag F_CIs set to “1”,
Next, the process proceeds to step S63, where the current gear ratio i,
Acceleration detection value X _G, Lateral acceleration detection value Y_GDrive according to
Luk's current value Tf_(n)Is calculated, then step 64
Is the current value Tf of this drive torque._(n)Is the target drive torque
This time value T ^* _(n)Is set, and then the process proceeds to step S65.
And the current value T of this target drive torque^* _(n)And current
Engine speed Ne_(n)Target throttle opening based on
The current value of degrees θ^* _(n)Is calculated. At this time,
Valued engine rotational drive torque should be reduced
From the current value θ of this target throttle opening^* _(n)Is sub
Positive to control the throttle valve 44 in the closing direction
Value, and therefore, the
In steps S77 to S79, the sub-throttle valve 44 is closed.
Throttle opening detection value TH in the same direction increases in the positive direction
Then, the throttle of the sub-throttle valve 44 in the closing direction is
Depending on the throttle opening and the amount of depression of the accelerator pedal 46
(Substantially with a corresponding response delay), the engine 20
Rotation speed Ne still increases while decreasing its increasing slope
Try to keep doing it.

In general, the sub-throttle valve 4
When the throttle opening control is performed in the closing direction of No. 4, the rotational driving force of the engine 20 continues to increase while decreasing its increasing slope because there is substantially a corresponding response delay as described above. Accordingly, the rear wheels 10RL, 1 which are driving wheels
The wheel speed detection values Vw _RL and Vw _{RR of} 0RR also try to keep increasing while decreasing their increasing slope. Therefore, the current value S _{(n) of the} drive wheel slip amount calculated in step S56 for each sampling time during which the calculation processing in FIG. 10 is executed.
Will continue to increase while decreasing its increasing slope, and then the slope will begin to decrease as a decreasing slope. Naturally, the absolute value of the change amount α of the slip amount calculated in step S57 will gradually increase in the positive region while gradually decreasing the absolute value in the negative region. Thus, immediately after the time t ₂₂ 10
In the driving force control apparatus according to the present embodiment, the throttle opening detection value TH (or target throttle opening θ ^* ) is controlled by the throttle opening control by the feedforward control as shown in FIG. The throttle opening TH _RF according to μ (or the target throttle opening θ ^* _RF according to road μ) is changed.

[0126] Wakashi, for each sampling time calculation of the time t ₂₂ after the Fig. 10 is executed, the step S
If it is determined in step 60 that the change amount α of the slip amount is smaller than the negative predetermined value α ₀ , the throttle opening control by the feedforward control described above is executed again, but this is the drive wheel. This _{means that} the current value S _(n) of the slip amount of the rear wheels 10RL and 10RR has not sufficiently decreased the increase speed with respect to the previous value S _(n-1) . This means that the opening degree control of the sub-throttle valve 44 should be executed in accordance with this, and that the throttle opening degree control by the feedforward control, that is, the original purpose of the driving force control is achieved. Conceivable.

The time t_{twenty two}The arithmetic processing of FIG. 10 immediately after
The throttle opening detection value TH (or the target
Throttle opening θ^*) Is the throttle opening according to the road μ
Degree TH_RF(Or target throttle opening θ according to road μ)^*
_RFIf the change control continues to be
Wheel speed Vw of the rear wheels 10RL and 10RR_RL, Vw _RR
Gradually decreases, so that the arithmetic processing of FIG. 10 is executed.
The value calculated in step S56 for each sampling time
Value S of the driving wheel slip amount_(n)Eventually its inclination
Starts to decrease as a decreasing slope,
The change amount α of the slip amount calculated in step S57 is
The absolute value gradually increases in the positive region. With this
The input / output shaft rotation speed ratio N of the torque converter 18 is also
The current value S of the driving wheel slip amount_(n)Start decreasing and time
Before and after, it starts to increase and its input / output shaft torque is the inverse ratio
The ratio T will begin to decrease. Here, the time t_{twenty two}
Sampling time during which the calculation processing of FIG. 10 is performed thereafter
In each case, the drive wheel slip calculated in step S55
The current value S of the quantity_(n)Is the predetermined value S₀Larger than
The change amount α of the slip amount calculated in step S57
Is the negative predetermined value α ₀Should be more than
After step S59 or step S60, step S6
1 and the feedback control flag F_CIs “1”
Since it is in the set state, the process proceeds to step S66,
Current value S of drive wheel slip amount_(n)Is still a very small positive
The predetermined value S of the value of₁Move to step S68
Target slip amount S^*Is calculated, and then step S7
0, the input shaft torque detection value T_inAnd output shaft
Luc detection value T_outAnd input / output in step S72.
The shaft torque ratio T is calculated, and in step S73, the proportional control gay
K_PAnd integral control gain K_ISearch by map. Only
However, at each sampling time at this time,
The input / output shaft torque ratio T calculated in step S72 is increasing.
And because it is considered to be a relatively large value,
Each control gain K retrieved and set in step S73_P,
K_IIs set to a relatively small value according to FIG.
Therefore, the drive torque increase calculated in the next step S73 is increased.
Current value of weight loss ΔT_(n)Is the control gain of this small value
K_P, K_IIs set to a small value by this small value
Current value ΔT of torque increase / decrease_(n)Using step S
At 74, the current value T of the target drive torque^* _(n)Is calculated,
Therefore, this target drive torque, which has a relatively small increase / decrease
Value T^* _(n)And the current engine speed Ne_(n)Based on
In step S65, the target throttle opening is
Value θ^* _(n)Is calculated, so that the steps S77-S
At 79, the throttle opening by the feedback control is performed.
Control is executed, and thereafter, the arithmetic processing of FIG.
The same flow as above for each sampling time performed
Is repeated, so that the rear wheel which is the driving wheel
Wheel speed Vw of 10RL, 10RR_RL, Vw_RRChange, immediately
The current value S of the drive wheel slip amount_{(n )}In response to changes in
Throttle opening control by feedback control is started
Will be. But the slots achieved as described above
Does the detected opening TH always have a small increase / decrease allowance?
If the road surface μ does not change significantly,
The throttle opening detection value TH is determined by the feedforward control.
According to the road surface μ achieved by throttle opening control
Throttle opening TH_RFWill be transitioned in the vicinity.

Eventually, the rear wheels 10RL,
As the wheel speeds Vw _RL and Vw _RR of 10RR decrease, the current value S _(n) of the drive wheel slip amount continues to decrease, that is, converges to a state where the vehicle can be started and accelerated according to the road surface μ. The output shaft rotation speed ratio N continues to increase, and the input / output shaft torque ratio T continues to decrease, during which the control gains K _P ,
Since the throttle opening control by the feedback control while changing the K _I is performed continues, the throttle opening detection value TH of the closing direction continues to remain at the vicinity of the throttle opening TH _RF in accordance with the road surface mu. Eventually, the time t _{23 at} which the continuously decreasing input / output shaft torque ratio T becomes “1”.
think of. The time t ₂₃ after, the sampling time for each arithmetic processing of FIG. 10 is executed, whether the present value S of the driving wheel slip amount calculated in the step S55 _(n) is greater than the predetermined value S ₀ Regardless of the above step S5
Since the amount of change in alpha is calculated slip amount should be the negative predetermined value alpha ₀ or 7, the process proceeds to step S61 through the step S59 or step S60, feedback control flag F _C is "1 since the set condition of "the process proceeds to step S66, the predetermined values S ₁ the current value S _(n) is still very small positive value of the driven wheel slip amount
Since greater than the process proceeds to step S68 and proceeds from the calculated target slip amount S ^* in step S70, the said input shaft torque detection value T _in and an output shaft torque detection value T _out
Loading calculates output shaft torque ratio T in step S72, the map search for proportional control gain K _P and the integral control gain K _I at step S73. However, at each sampling time at this time, the input / output shaft torque ratio T calculated in the step S72 is “1”, that is, it is considered that the torque amplifying action of the torque converter 18 has been eliminated, so that in the step S73. The control gains K _P and K _I to be searched and set are respectively set to the relatively large predetermined values K _P0 and K _{I0 according} to FIG. Accordingly, the present value ΔT _(n) of the drive torque increase / decrease amount calculated in the next step S73 is set to a large value by the control gains K _P and K _I of the large values, and the torque increase / decrease amount of this large value is set. Using the current value ΔT _(n) , step S
At 74, the current value T ^* _{(n) of the} target drive torque is calculated,
Therefore, in step S65, the current value θ ^* _{(n) of the} target throttle opening is calculated based on the current value T ^* _{(n) of the} target drive torque and the current engine rotation speed Ne _(n) having a relatively small increase / decrease margin. Therefore, steps S77-S
At 79, the throttle opening control by the feedback control is executed, and thereafter, the same flow as described above is repeated every sampling time when the calculation processing of FIG. 10 is executed. , The throttle opening degree control by feedback control according to the change in the wheel speeds Vw _RL , Vw _RR of the rear wheels 10RL, 10RR, that is, the change in the current value S _(n) of the drive wheel slip amount is started. At this time, the throttle opening detection value TH achieved as described above has a large increase / decrease margin, so that the responsiveness of the control is improved and the current value S _(n) of the drive wheel slip amount is set to the value. Since it is considered that the state has converged to a state sufficient to start and accelerate the vehicle on the road surface μ, the throttle opening detection value TH in the closing direction is determined by the road surface μ achieved by the throttle opening control by the feedforward control. Will be changed in the vicinity of the throttle opening TH _RF corresponding to the above.

During this time, the input / output shaft rotational speed ratio N of the torque converter 18 continues to increase smoothly, and the input / output shaft torque ratio T also keeps decreasing smoothly. Therefore, when the vehicle starts and accelerates substantially, The feeling of acceleration felt by the driver will be stable, and at the same time, the vehicle will be able to realize stable starting acceleration. Of course, the rear wheel 10 which is the driving wheel
Since the slips of the RL and 10RR are converged in a relatively short time by the throttle opening control by the feedforward control, the running stability is not impaired when the vehicle starts and accelerates.

On the other hand, according to the conventional driving force control device,
Time t_{twenty two}Immediately after
Immediately after the throttle opening control, the normal control gain K_P,
K_I(= Predetermined value K_P0, K_I0) Feedback system
The throttle opening control by the control will be started
At this time, the throttle opening by feedback control
The present value S of the drive wheel slip amount which is a control factor of the control_(n)
Focusing solely on the fact that it is still going to increase,
In the throttle opening control by the feedback control,
Throttle opening detection value TH of sub throttle valve 44
_P(Or target throttle opening θ^* _(n)) Is the closing direction
Will continue to increase. As a result, the engine drive
Power is greatly reduced (rotational speed Ne also decreases at the same time)
12a), the drive wheel slide as shown in FIG.
Lip amount S_PDecrease faster. However, these
Accordingly, the input / output shaft rotation speed ratio N of the torque converter_PAlso steep
The input / output shaft torque ratio T_P
Will be sharply reduced, as mentioned above
The operating area of the torque converter in the converter area is strong.
To or in the fluid coupling area
Will be migrated. However, on the other hand, the engine
The rotational driving force of the
Coupling area, ie, directly connected state or almost directly connected state
Cannot rotate the drive wheels sufficiently.
As shown in FIG. _PDrops to almost zero
Into, that is, simply running by inertia or running
The driver will not feel too much acceleration.
On the contrary, it is felt as a feeling of deceleration.

In the driving force control calculation process of this embodiment, the vehicle shifts to a steady running state, for example, on a high μ road surface, and as a result, the current value S _{(n) of the} driving wheel slip amount is extremely reduced. becomes smaller than the predetermined values S ₁ a small positive value, steps that the amount of change alpha is smaller than the predetermined value alpha ₁ for the very small positive value, through steps S66, S69 of the arithmetic processing of FIG. 10 at the same time the feedback control flag F _C at S67 is reset to "0", thereafter, sets the current value of the target throttle opening theta ^* a _(n) "0" in the step S76, the fully open the sub-throttle valve 44 The control is returned to the state, and the control is shifted to the control for maximizing the rotational driving force of the engine 20 according to the depression amount of the accelerator pedal 46.

As described above, this embodiment corresponds to claim 3 of the present invention.
It is considered that the driving force control device according to the present invention is implemented.
57 corresponds to the driving wheel slip state detecting means of the driving force control device according to claim 3 of the present invention.
Steps S10 and S71 of the arithmetic processing of 0 correspond to the torque increase amount detecting means, and steps S72 and S71 of the arithmetic processing of FIG.
Corresponds to the control gain setting means, and steps S63 and S64 of the calculation processing of FIG. 10 correspond to the first output reduction amount calculation means, and steps S68, S73, and S7 of the calculation processing of FIG.
4 corresponds to the second output reduction amount calculating means, and the other calculation processing steps of the calculation processing in FIG. 10 correspond to the engine output adjusting means.

In the above embodiment, the case where a microcomputer is applied as the controller 30 has been described. However, the present invention is not limited to this, and may be configured by combining electronic circuits such as a function generator and an arithmetic circuit. Can also. Further, in the above embodiment, the case where the pressure control is performed by applying the pressure control valve as the control valve has been described. However, the present invention is not limited to this, and the flow control may be performed by applying the flow control valve.

In the above embodiment, the case where the driving force control device controls both the throttle opening and the braking force of the driving wheels has been described. However, at least in the present invention, the control of the braking force of the driving wheels is indispensable. Since this is not a requirement, it can be omitted. However, as described above, it is desirable that the engine rotational driving force control by the throttle opening control be provided with the braking force control of the driving wheels because of a response delay.

In the above-described embodiment, the wheel speed detection value of the non-driving wheel, that is, the driven wheel, and the wheel speed detection value of the driving wheel are used for calculating the slip ratio and the slip amount. However, the pseudo vehicle speed is calculated by applying a pseudo vehicle speed calculating means used in, for example, an anti-skid control device, and the pseudo vehicle speed is converted into a wheel speed to be used as a wheel speed of a driven wheel, that is, a vehicle body speed. You may do so.

Further, in the above embodiment, the case where the working oil is used as the working fluid has been described. However, the present invention is not limited to this, and another fluid having low compressibility can be used. Further, in the above-described embodiment, a case has been described in which the driving force control device of the present invention is applied to a rear-wheel drive vehicle, but the present invention can also be applied to a front-wheel drive vehicle or a four-wheel drive vehicle. However, in the case of a four-wheel drive vehicle, since there are basically no non-drive wheels and driven wheels, the pseudo vehicle speed calculation means used in the anti-skid control device may be applied as described above.

[0137]

As described above, according to the driving force control apparatus according to the first or second aspect of the present invention, for example, the feedback control amount which is the feedback control amount when the operating region of the torque converter is in the fluid coupling region. (2) Select the engine output reduction amount by the output reduction amount calculating means, and select the engine output reduction amount by the second output reduction amount calculating means which is the feedforward control amount in the converter region, and reduce the engine output based on these. Since the control is executed, the torque amplifying action of the torque converter is not compensated, and the running stability can be improved while securing sufficient vehicle acceleration.

Further, according to the driving force control device of the third aspect of the present invention, the amount of increase in the torque of the torque converter is reduced.
The larger the value, the smaller the control gain of the second output reduction amount calculation means used for calculating the feedback control amount is set, and
Since the engine output reduction control is executed based on the engine output reduction amount, the torque amplifying action of the torque converter is not compensated for, or the compensation margin is reduced, and sufficient vehicle acceleration is achieved. It is also possible to improve running stability while securing.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram showing an outline of the present invention.

FIG. 2 is a schematic configuration diagram showing a first embodiment of a driving force control device of the present invention.

FIG. 3 is a block diagram illustrating an example of a controller illustrated in FIG. 2;

FIG. 4 is a flowchart of a calculation process of braking force control executed by the controller of FIG. 3;

FIG. 5 is an explanatory diagram showing a control mode conversion map for setting a control mode based on a slip rate and a slip rate change speed that can be applied in the arithmetic processing of FIG. 4;

FIG. 6 is a flowchart of a calculation process of engine output reduction control executed by the controller of FIG. 3;

7 is an operation explanatory diagram of engine output reduction control executed in the calculation processing of FIG. 6;

FIG. 8 is a schematic configuration diagram showing a second embodiment of the driving force control device of the present invention.

FIG. 9 is a block diagram illustrating an example of a controller illustrated in FIG. 8;

FIG. 10 is a flowchart of a calculation process of engine output reduction control executed by the controller of FIG. 9;

11 is an explanatory diagram showing a control map of input / output shaft torque ratios and control gains applicable in the calculation processing of FIG. 10;

12 is an operation explanatory diagram of the engine output reduction control executed in the calculation processing of FIG. 10;

[Explanation of symbols]

 10FL, 10FR are front wheels (non-drive wheels) 10RL, 10RR are rear wheels (drive wheels) 14 is an automatic transmission 18 is a torque converter 20 is an engine 26 is a lateral acceleration sensor 28FL-28RR is a wheel speed sensor 30 is a controller 34 is an automatic Transmission control devices 38a, 38b are torque sensors 39a, 39b are rotational speed sensors 40 are longitudinal acceleration sensors 42 are throttle opening sensors 44 are sub-throttle valves 45 are step motors 46 are accelerator pedals 47 are accelerator sensors 48 are main throttle valves 50 is a brake pedal 51 is a brake master cylinder 52FL-52RR is a wheel cylinder 54L, 54R is a hydraulic pressure control valve 70L, 70R is a solenoid valve 84 is a microcomputer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02D 29/02 311

Claims (3)

(57) [Claims] 1. A vehicle in which output of an engine is transmitted to driving wheels via a torque converter, wherein a driving wheel slip state detecting means for detecting a slip state of the driving wheels, and detecting an operation area of the torque converter. Operating region detecting means, first output reduction amount calculating means for calculating an engine output reduction amount corresponding to the load on the driving wheels received from the road surface, and a driving wheel slip state detected by the driving wheel slip state detecting means. A second output reduction amount calculating means for calculating a reduction amount of the engine output in accordance with the first output reduction amount calculating means and a second output reduction amount in accordance with an operating area of the torque converter detected by the operating area detecting means. Selecting means for selecting one of the calculating means; and an engine output adjusting means for adjusting the output of the engine in accordance with the engine output reduction amount of any of the output reducing amount calculating means selected by the selecting means. A driving force control device, comprising: 2. The method according to claim 1, wherein the selecting unit selects the first output reduction amount calculating unit when an operating region of the torque converter detected by the operating region detecting unit is a converter region, and selects the first output reduction amount calculating unit when the operating region is a fluid coupling region. 2. The method according to claim 1, wherein the second output reduction amount calculating means is selected.
3. The driving force control device according to claim 1. 3. A vehicle in which an output of an engine is transmitted to driving wheels via a torque converter, wherein a driving wheel slip state detecting means for detecting a slip state of the driving wheels, and detecting a torque increase amount of the torque converter. Torque increase amount detecting means, a first output reduction amount calculating means for calculating an amount of reduction in engine output corresponding to the load of the drive wheel received from the road surface, and slip of the drive wheel detected by the drive wheel slip state detecting means. a second output reduction amount calculating means for calculating an in accordance with the state reduction amount of the engine output by using a predetermined control gain, as the amount of increase in torque of the torque converter, which is detected by the torque increase amount sensing means is larger the second Control gain setting means for setting the control gain of the output reduction amount calculating means to a small value; and adjusting the output of the engine according to the engine output reduction amount of any of the output reduction amount calculating means. A driving force control device comprising: