JP2621667B2 - Vehicle output control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control device for a vehicle which rapidly reduces the driving torque of an engine in accordance with the magnitude of a lateral acceleration generated when the vehicle turns and improves the turning performance of the vehicle.

[0002]

2. Description of the Related Art When a vehicle is running on a road surface having a low coefficient of friction, such as a snowy road or an icy road, the driving wheels are idle when the road surface condition changes suddenly while the vehicle is running.
As a result, the running performance of the vehicle decreases.

In such a case, it is very difficult even for a skilled person to adjust the depression amount of the accelerator pedal and delicately control the output of the engine so that the driving wheels do not run idle. .

Similarly, a centrifugal force corresponding to the lateral acceleration in a direction perpendicular to the traveling direction is generated in a vehicle traveling on the circuit, and when the traveling speed of the vehicle with respect to the circuit is too high, There is a possibility that the vehicle body may skid beyond the limit of the grip force of the tire.

In such a case, in order to properly lower the output of the engine and safely drive the vehicle with a turning radius corresponding to the turning circuit, particularly when the exit of the turning circuit cannot be confirmed, or when the turning circuit of the turning circuit is not detected. In the case where the radius of curvature becomes gradually smaller, an extremely advanced driving technique is required.

In a general vehicle having a so-called understeering tendency, it is necessary to gradually increase the steering amount with an increase in the lateral acceleration applied to the vehicle . In particular, in a vehicle of a strong front-engine front-wheel drive type of under-steering tendency, it is well known as this tendency becomes prominent.

[0007] Accordingly, the idling state of the driving wheels is detected, and when the idling of the driving wheels occurs, the output of the engine is forcibly reduced regardless of the amount of depression of the accelerator pedal by the driver. Or the lateral acceleration of the vehicle is detected, and before the turning radius of the vehicle increases relative to the driver's intention , the engine is forcibly forced regardless of the amount of depression of the accelerator pedal by the driver. An output control device that reduces the output of the vehicle is conceivable, and the driver uses the output control device as necessary, and a normal drive that controls the output of the engine according to the amount of depression of the accelerator pedal. And what can be selected has been announced.

[0008] Of those related to the output control of a vehicle based on such a viewpoint, a conventionally known one detects, for example, the rotational speed of a drive wheel and the rotational speed of a driven wheel, and drives the difference between these rotational speeds. The output torque of the engine is controlled in accordance with the slip amount of the wheels, or the drive torque of the engine is controlled based on the yawing amount of the vehicle (hereinafter referred to as the yaw rate). It was done.

That is, in the latter method, yaw and the like mainly occurring during a high-speed sharp turn of the vehicle tend to rapidly increase as the vehicle speed is increased and the steeper turn is made. When the yaw rate is detected or exceeds a predetermined value, the output torque of the engine is reduced.

By using this output control device, it is possible to reduce shocks and the like during shifting in an automatic transmission.

[0011]

However, in the above-described turning control device, since only the condition of the vehicle body is detected and the driving force is controlled, there is also a dissatisfaction point in drivability. For example, the driver wants to accelerate from the vicinity of the exit of the circuit, but the driving force has been determined irrespective of the depression amount of the accelerator pedal, so that the driver's will was not reflected.

[0012]

According to the present invention, there is provided a vehicle output control apparatus comprising: a torque control means for reducing an output torque of an engine independently of an operation by a driver; A steering angle sensor for detecting a turning angle, a vehicle speed sensor for detecting the speed of the vehicle, a rotation speed sensor for detecting the rotation speed of the engine, an accelerator opening sensor for detecting the accelerator opening, the steering angle sensor and the vehicle speed A lateral acceleration of the vehicle is calculated based on a detection signal from a sensor, and a reference drive torque corresponding to the magnitude of the lateral acceleration is calculated. On the other hand, the required drive torque is determined based on the detection signals from the rotation speed sensor and the accelerator opening sensor, and the ratio of adoption of the required drive torque is determined to correct the required drive torque. The target drive torque is calculated from the corrected reference drive torque and the corrected required drive torque, and the reference drive torque and the required drive torque are further calculated according to the increase in the steering shaft turning angle according to the steering wheel turning amount. A torque calculation unit for calculating a target drive torque by changing an adoption ratio, and an electronic control unit for controlling the torque control means so that the output torque of the engine becomes the target drive torque.

As a torque control means for reducing the output torque of the engine, it is common to delay the ignition timing, reduce the intake air amount or the fuel supply amount, or stop the fuel supply. In addition, as a special type, a type in which the compression ratio of the engine is reduced may be employed.

[0014]

The torque calculation unit calculates the lateral acceleration of the vehicle based on the detection signal from the steering angle sensor and the detection signal from the vehicle speed sensor, and calculates a reference driving torque according to the magnitude of the lateral acceleration. The required drive torque is determined based on the detection signals from the rotation speed sensor and the accelerator opening sensor, and the required drive torque is determined. Then, a target drive torque is calculated from the correction reference drive torque and the correction request drive torque, and the target drive torque is output to the electronic control unit.

When the target drive torque of the engine is output from the torque calculation unit to the electronic control unit, the electronic control unit controls the operation of the torque control means so that the output torque of the engine becomes the target drive torque, and controls the operation of the engine. The output torque is reduced to prevent the lateral acceleration of the vehicle from increasing.

With the turning of the circuit, the adoption ratio of the reference drive torque decreases, while the adoption ratio of the required drive torque increases, so that the turning traveling gradually meets the driver's request.

However, when the amount of additional turning of the steering wheel increases, it means that the radius of curvature of the circuit becomes smaller. Therefore, the ratio of adopting the reference drive torque is increased in accordance with the amount of additional turning of the steering wheel. Calculate the target drive torque.

By doing so, even if the shape of the circuit changes, it is possible to reliably and easily perform the turning operation with an output state suitable for the change.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1 showing the concept of an embodiment in which a vehicle output control device according to the present invention is applied to a front-wheel drive type vehicle and FIG. A throttle valve 15 for adjusting the amount of intake air supplied into the combustion chamber 12 by changing the opening of an intake passage 14 formed by the intake pipe 13 is installed in the middle of an intake pipe 13 connected to the intake pipe 12. The throttle body 16 is interposed. As shown in FIG. 1 and FIG. 3 showing an enlarged cross-sectional structure of a cylindrical portion of the throttle body 16, both ends of a throttle shaft 17 having a throttle valve 15 integrally fixed thereto are rotatable. Supported. An accelerator lever 18 and a throttle lever 19 are fitted coaxially with one end of the throttle shaft 17 projecting into the intake passage 14.

The throttle shaft 17 and the accelerator lever 1
Bush 21 and spacer 22
The accelerator lever 18 is rotatable with respect to the throttle shaft 17. Further, an accelerator lever 18 is moved from the throttle shaft 17 by a washer 23 and a nut 24 attached to one end of the throttle shaft 17.
Is prevented from coming off. An accelerator pedal 26 operated by a driver is connected to a cable receiver 25 integral with the accelerator lever 18 via a cable 27. The accelerator lever 18 is connected to a throttle shaft according to the amount of depression of the accelerator pedal 26. 17.

On the other hand, the throttle lever 19 is fixed integrally with the throttle shaft 17. Therefore, by operating the throttle lever 19, the throttle valve 1 is operated.
5 rotates together with the throttle shaft 17. A collar 28 is fitted coaxially and integrally with the cylinder portion 20 of the accelerator lever 18, and the tip of the throttle lever 19 is engaged with a claw portion 29 formed on a part of the collar 28. A stopper 30 is formed. The claw portion 29 and the stopper 30 are engaged with each other when the throttle lever 19 is turned in a direction in which the throttle valve 15 opens or the accelerator lever 18 is turned in a direction in which the throttle valve 15 closes. Is set in a proper positional relationship.

Between the throttle body 16 and the throttle lever 19, a torsion coil spring 3 for pressing the stopper 30 of the throttle lever 19 against the claw portion 29 of the accelerator lever 18 to urge the throttle valve 15 in the opening direction is provided.
1 is mounted coaxially with the throttle shaft 17 via a pair of cylindrical spring supports 32 and 33 fitted to the throttle shaft 17. Also, throttle body 1
6 and a stopper pin 34 protruding from the accelerator lever 18
A torsion coil spring for pressing the claw portion 29 of the accelerator lever 18 against the stopper 30 of the throttle lever 19 to urge the throttle valve 15 in the closing direction to give a detent feeling to the accelerator pedal 26 35
Is the cylindrical portion 2 of the accelerator lever 18 via the collar 28.
0 is mounted coaxially with the throttle shaft 17.

At the tip of the throttle lever 19,
The distal end of a control rod 38 whose base end is fixed to the diaphragm 37 of the actuator 36 is connected. A compression coil spring which presses the stopper 30 of the throttle lever 19 together with the torsion coil spring 31 against the claw portion 29 of the accelerator lever 18 to urge the throttle valve 15 in an opening direction is provided in a pressure chamber 39 formed in the actuator 36. 40
Is incorporated. And these two springs 31,
The spring force of the torsion coil spring 35 is set to be greater than the sum of the spring forces of the springs 40, so that the accelerator pedal 26 is depressed or the pressure in the pressure chamber 39 is reduced by the spring forces of the two springs 31, 40. The throttle valve 15 is not opened unless the negative pressure is larger than the sum.

A surge tank 41 which is connected to the downstream side of the throttle body 16 and forms a part of the intake passage 14
Is connected to a vacuum tank 43 via a connection pipe 42, and the vacuum tank 43 and the connection pipe 42
Between the vacuum tank 43 and the surge tank 4
A non-return valve 44 that allows only the movement of air to 1 is interposed. Thus, the pressure in the vacuum tank 43 is set to a negative pressure substantially equal to the lowest pressure in the surge tank 41.

The inside of the vacuum tank 43 and the pressure chamber 39 of the actuator 36 are in communication with each other via a pipe 45. In the middle of the pipe 45, a non-energized closed first torque control An electromagnetic valve 46 is provided. That is, the pipe 45 is connected to the torque control solenoid valve 46.
A spring 49 for urging the plunger 47 against the valve seat 48 so as to close the valve is incorporated.

A pipe 45 communicating with the intake passage 14 upstream of the throttle valve 15 is provided in a pipe 45 between the first torque control solenoid valve 46 and the actuator 36.
Is connected. In the middle of the pipe 50, a second torque control solenoid valve 51 which is open when not energized is provided. That is, the torque control solenoid valve 51 is provided with a spring 5 for urging the plunger 52 to open the pipe 50.
3 are incorporated.

The two torque control solenoid valves 46, 51
An electronic control unit (hereinafter, referred to as an ECU) 54 for controlling the operating state of the engine 11 is connected to each of them, and based on a command from the ECU 54, the energization of the torque control solenoid valves 46, 51 is turned on. , Off are duty-controlled, and in the present embodiment, the whole of them constitutes the torque control means of the present invention.

For example, when the duty ratio of the torque control solenoid valves 46 and 51 is 0%, the pressure chamber 39 of the actuator 36 is connected to the intake passage 14 upstream of the throttle valve 15.
Atmospheric pressure is almost equal to the pressure inside the throttle valve 15
Corresponds to the amount of depression of the accelerator pedal 26 on a one-to-one basis. Conversely, when the duty ratios of the torque control solenoid valves 46 and 51 are 100%, the pressure chamber 39 of the actuator 36 has a negative pressure substantially equal to the pressure in the vacuum tank 43, and the control rod 38 is inclined diagonally to the left in FIG. As a result, the throttle valve 15 is closed regardless of the depression amount of the accelerator pedal 26, and the output torque of the engine 11 is forcibly reduced. In this way,
By adjusting the duty ratio of the torque control solenoid valve 46 and 51, to change the degree of opening of the throttle valve 15 regardless of the amount of depression of the accelerator pedal 26, out of the engine 11
The force torque can be adjusted arbitrarily.

The ECU 54 includes a crank angle sensor 55 attached to the engine 11 for detecting an engine speed.
A throttle opening sensor 56 attached to the throttle body 16 to detect the opening of the throttle lever 19;
An idle switch 57 for detecting the fully closed state of the throttle valve 15 is connected, and output signals from the crank angle sensor 55, the throttle opening sensor 56, and the idle switch 57 are sent.

Further, a torque calculation unit for calculating a target driving torque of the engine 11 (hereinafter referred to as TCL)
58, an accelerator opening sensor 59 attached to the throttle body 16 together with the throttle opening sensor 56 and the idle switch 57 to detect the opening of the accelerator lever 18, and a pair of left and right front wheels 60, 61 as driving wheels.
Front wheel rotation sensors 62 and 6 for detecting the rotation speeds of
3, rear wheel rotation sensors 66 and 67 for detecting rotation speeds of a pair of left and right rear wheels 64 and 65 as driven wheels, respectively, and a steering shaft 6 at the time of turning based on the straight traveling state of the vehicle 68.
9 is connected to a steering angle sensor 70 for detecting a turning angle, and output signals from these sensors 59, 62, 63, 66, 67, 70 are sent, respectively.

The ECU 54 and the TCL 58 are connected via a communication cable 71. The ECU 54 provides information on the operating state of the engine 11, such as the engine speed and the detection signal from the idle switch 57, as well as the amount of intake air. Sent to TCL 58. Conversely, information about the target drive torque calculated by the TCL 58 is sent from the TCL 58 to the ECU 54.

As shown in FIG. 4 showing a rough flow of the control according to the present embodiment, in the present embodiment, the target drive torque T _OS of the engine 11 when the slip control is performed and the friction coefficient such as a dry road. The target driving torque T _OH of the engine 11 when turning control is performed on a relatively high road surface (hereinafter referred to as a high μ road) and a relatively low friction coefficient such as a frozen road or a wet road. Target drive torque T of engine 11 when turning control is performed on a low road surface (hereinafter, referred to as a low μ road).
_OL is always calculated in parallel by the TCL 58, and the optimum final target drive torque T ₀ is selected from these three target drive torques T _OS , T _OH , and T _OL, and the output torque of the engine 11 is changed as necessary. So that it can be reduced.

More specifically, a control program of the present embodiment is started by turning on an ignition key (not shown). At M1, an initial value δ _{m (o)} of the steering shaft turning position is read, and various flags are set. Initialization such as resetting or starting counting of the main timer every 15 milliseconds, which is the sampling period of this control, is performed.

[0034] Then, TCL 58 based on the detection signals from various sensors at M2 calculates a vehicle speed V or the like, this followed by learning correction at the neutral position [delta] _M and M3 of the steering shaft 69. Neutral position [delta] _M of the steering shaft 69 of the vehicle 68, wherein at an initial value δ _{m (o)} is read each time the ignition key turned on, the initial value δ _{m (o)} the vehicle 68 will be described later straight The learning correction is performed only when the driving condition is satisfied, and the initial value δ is maintained until the ignition key is turned off.
_{m (o)} is learned and corrected.

Next, the TCL 58 is driven by the front wheels 60, 6 at M4.
Out of the engine 11 based on the rotational difference between the rear wheel 64, 65 1 and
The target drive torque T _OS when the slip control for restricting the force torque is performed is calculated, and the target drive torque T _OH of the engine 11 when the turning control on the high μ road is performed at M5. 1 when turning control is performed on a low μ road at
One target drive torque T _OL is sequentially calculated.

Then, at M7, the TCL 58 selects an optimal final target drive torque T _O from the target drive torques T _OS , T _OH , and T _OL by a method described later.
The ECU 54 sets a pair of torque control solenoid valves 46 and 51 so that the output torque becomes the final target drive torque T _O.
Is controlled so that the vehicle 68 can travel safely without difficulty.

As described above, the output torque of the engine 11 is reduced to M8
Control until the countdown of the main timer ends,
Thereafter, the countdown of the main timer is started again at M9, and the steps from M2 to M9 are repeated until the ignition key is turned off.

The reason why the neutral position δ _M of the steering shaft 69 is learned and corrected in the step M3 is that the front wheel 6
The deviation between the turning amount of the steering shaft 69 and the actual steering angle δ of the front wheels 60 and 61, which are the steered wheels, occurs when the toe-in adjustment of 0 or 61 is performed or due to aging such as wear of a steering gear (not shown). This occurs because the neutral position δ _M of the steering shaft 69 may change.

As shown in FIGS. 5 and 6 showing the procedure for learning and correcting the neutral position δ _M of the steering shaft 69, the TCL 58
Is based on detection signals from the rear wheel rotation sensors 66 and 67,
At C1, the vehicle speed V is calculated by the following equation (1). V = (V _RL + V _RR ) / 2 (1) where V _RL and V _RR are the peripheral velocities of the pair of left and right rear wheels 64 and 65, respectively.

Next, the TCL 58 calculates a difference in peripheral speed between the pair of left and right rear wheels 64 and 65 (hereinafter referred to as a rear wheel speed difference) | V _RL -V _RR | in C2. After a while, TCL
58 determines at C3 whether the vehicle speed V is greater than a preset threshold value _VA . This operation is performed when the vehicle 68 does not reach a certain high speed, and the rear wheel speed difference | V _RL −V _{RR due to} steering is _generated.
Etc. cannot be detected, and the threshold value _VA is determined by an experiment based on the running characteristics of the vehicle 68 and the like.
For example, it is appropriately set to 20 km / h.

[0041] When it is determined that the vehicle speed V is the threshold value V _A above, TCL 58 rear wheel speed difference at C4 | V _RL
-V _RR | is preset, or less or not than such threshold value V _B of example hourly 0.1km, i.e. determines whether the vehicle 68 is running straight. Here, hourly threshold V _B 0 km
The reason is that when the tire pressures of the left and right rear wheels 64 and 65 are not equal, the peripheral velocities V _RL and V _{RR of the} pair of left and right rear wheels 64 and 65 are different even though the vehicle 68 is in a straight traveling state. This is because

In step C4, the rear wheel speed difference | V _RL −
If it is determined that V _RR | is equal to or less than the threshold value V _B , TCL
58 is the previous steering shaft turning position δ _{m (n-1)} detected by the steering angle sensor 70 at the current steering shaft turning position δ _{m (n)} at C5.
It is determined whether it is the same as. At this time, the steering angle sensor 70 is controlled so as not to be affected by the shake of the driver.
It is desirable to set the resolution for detecting the turning of the steering shaft 69 by, for example, about 5 degrees.

If it is determined in step C5 that the current steering shaft turning position δm _(n) is the same as the previous steering shaft turning position δm _(n-1) , the TCL 58 determines the current steering shaft turning position δm _(n-1) in C6. It is determined that the vehicle 68 is in the straight traveling state, and the learning timer (not shown) built in the TCL 58 is counted up.

Next, the TCL 58 is a learning timer at C7.
It is determined whether or not 0.5 seconds have elapsed after counting up, that is, whether or not the straight traveling state of the vehicle 68 has continued for 0.5 seconds. In this case, since the learning timer has not counted up for 0.5 seconds at the beginning of the running of the vehicle 68, the steps from C1 to C7 are repeated at the beginning of the running of the vehicle 68.

Then, the learning timer is counted up.
When it is determined that 0.5 seconds have passed since
Determines whether the steering angle neutral position learned flag FH is set in C8, that is, whether the current learning control is the first time.

[0046] When the steering angle neutral position learned flag F _H is determined in step C8 is determined not to be set, the current steering shaft turning position at C9 δ _{m (n)} a new steering shaft 69 read into the memory of the TCL58 considered neutral position [delta] _{M (n),} and sets the steering angle neutral position learned flag F _H.

After the new neutral position δ _{M (n)} of the steering shaft 69 is set in this way, the turning angle δ _H of the steering shaft 69 is determined based on the neutral position δ _{M (n)} of the steering shaft 69. On the other hand, the count of the learning timer is cleared at C10, and the steering angle neutral position learning is performed again.

The steering angle neutral position learned flag F _H is determined in step C8 is set, that is, if the steering angle neutral position learning is determined to be the second or later, TCL 58
In C11, the current steering shaft turning position δm _(n) is _equal to the previous neutral position δM _(n-1) of the steering shaft 69, that is, δm _(n) = δM _(n-1) . Determine if there is. If it is determined that the current steering shaft turning position δ _{m (n)} is _equal to the previous neutral position δ _{M (n-1)} of the steering shaft 69, the process returns to step C10 and returns to the next steering angle neutral position again. Position learning is performed.

At step C11, it is determined that the current steering shaft turning position δm _(n) is not equal to the previous neutral position δM _(n-1) of the steering shaft 69 due to play in the steering system or the like. if you did this,
The current steering axis turning position δ _{m (n) is used} for the new steering axis 6 as it is.
9 without determining the neutral position [delta] _{M (n),} when the absolute value is different correction limit amount Δδ greater than or equal to the preset of these differences, the neutral position [delta] _M of the previous steering shaft 82 _{(n- A} value obtained by subtracting or adding the correction limit amount Δδ to ₁₎ is set as a new neutral position δM _{(n) of the} steering shaft 69 and is read into a memory in the TCL 58.

That is, the TCL 58 calculates the neutral position δ of the previous steering shaft 69 from the current steering shaft turning position δ _{m (n)} at C12.
_The value obtained by subtracting _{M (n-1)} is a preset negative correction limit amount-Δ
It is determined whether it is smaller than δ. And this C12
If it is determined that the value subtracted in the step is smaller than the negative correction limit amount -Δδ, the neutral position δ _{M (n)} of the new steering shaft 69 is changed to the neutral position of the previous steering shaft 69 at C13. From the position δ _{M (n-1)} and the negative correction limit amount −Δδ, change δ _{M (n)} = δ _{M (n-1)} −Δδ, and the learning correction amount per time is unconditionally negative. Care is taken not to become too large.

Thus, even if an abnormal detection signal is output from the steering angle sensor 70 for some reason,
Neutral position [delta] _M of the steering shaft 69 is not in the sudden change, it is possible to cope with the abnormality quickly.

On the other hand, if it is determined that the value subtracted in the step C12 is larger than the negative correction limit amount -Δδ, in C14, the current steering shaft turning position δ _{m (n) is used} to determine the value of the previous steering shaft rotation. It is determined whether or not a value obtained by subtracting the neutral position δM _(n−1) from 69 is larger than the positive correction limit amount Δδ. The value subtracted in the step C14 is a positive correction limit amount Δ
When it is determined that the neutral position is larger than δ, the neutral position δ _{m (n)} of the new steering shaft 69 is set to the neutral position δ _{M (n−1)} of the previous steering shaft 69 and the positive correction limit Δδ at C15. From this, δM _(n) = δM _(n-1) + Δδ is changed so that the amount of learning correction per time is not unconditionally increased to the positive side.

Thus, even if an abnormal detection signal is output from the steering angle sensor 70 for some reason,
Neutral position [delta] _M of the steering shaft 69 is not in the sudden change, it is possible to cope with the abnormality quickly.

However, if it is determined that the value subtracted in step C14 is smaller than the positive correction limit Δδ,
At C16, the current steering shaft turning position δm _(n) is read out as it is as the new neutral position δM _(n) of the steering shaft 69.

Accordingly, when the stopped vehicle 68 starts with the front wheels 60 and 61 kept in a turning state, as shown in FIG. 7 showing an example of a change state of the neutral position δ _M of the steering shaft 69 at this time. when learning control neutral position [delta] _M of the steering shaft 69 is for the first time, the correction amount from the initial value of the steering shaft turning position δ _{m (o)} in step M1 as described above is a very large, the second time The subsequent neutral position δ _M of the steering shaft 69 is C13,
The state is suppressed by the operation in the step C14.

Thus, the neutral position δ _{M of the} steering shaft 69 is obtained.
After learning and correcting the vehicle speed V and the peripheral speed V of the front wheels 60 and 61.
A target drive torque T _OS for performing slip control for regulating the drive torque of the engine 11 based on the difference between _PL and V _FR is calculated.

In order to make the output torque generated by the engine 11 work effectively, as shown in FIG. 8 showing the relationship between the coefficient of friction between the tire and the road surface and the slip ratio of the tire, The slip amounts s of the front wheels 60 and 61 are adjusted so that the slip ratio S of the tires 60 and 61 is at or near the target slip ratio S _O corresponding to the maximum value of the coefficient of friction between the tire and the road surface, It is desirable that the acceleration performance of the vehicle 68 is not impaired. Here, the slip ratio S of the tire is S = [{(V _FL + V _FR ) / 2} −V] / V, and the slip ratio S corresponds to the maximum value of the coefficient of friction between the tire and the road surface. The target drive torque T _OS of the engine 11 is set so as to be at or near the slip ratio S _O , and the calculation procedure is as follows.

First, the TCL 58 is calculated based on the current vehicle speed V _(n) calculated by the above equation (1) and the vehicle speed V _(n-1) calculated immediately before.
From, is calculated by the following equation longitudinal acceleration G _X current vehicle 68. _{G X = (V (n)} -V (n-1)) / (3.6 · Δt · g) However, Delta] t is the sampling period of the main timer 15 ms, g is the gravitational acceleration.

The driving torque T of the engine 11 at this time is
_B is calculated by the following equation (2). T _B = G _XF · W _b · r + T _R (2) where G _XF is a corrected longitudinal acceleration that has passed through a low-pass filter that delays the change in the longitudinal acceleration G _X described above. The low-pass filter can determine that the longitudinal acceleration G _X of the vehicle 68 is equivalent to the coefficient of friction between the tire and the road surface, so that the longitudinal acceleration G _X of the vehicle 68 changes and the slip ratio S of the tire becomes The slip rate S of the tire is set to the target slip rate S corresponding to the maximum value of the coefficient of friction between the tire and the road surface even if the slip rate is likely to deviate from or near the target slip rate S _O corresponding to the maximum value of the coefficient of friction between
_O or, as it is maintained in the vicinity thereof, the longitudinal acceleration G _X
Has the function of correcting Further, W _b is the body weight, r is the effective radius, T _R is running resistance of the front wheels 60 and 61, although the running resistance T _R can be calculated as a function of the vehicle speed V, the in this example 9 Is obtained from the map shown in Fig.

On the other hand, while the vehicle 68 is accelerating, the wheel slip amount is usually about 3% with respect to the road surface, and when traveling on a rough road such as a gravel road, etc. Low μ
Generally, the maximum value of the coefficient of friction between the tire and the road surface corresponding to the target slip ratio S _O is larger than when traveling on a road. Therefore, the target driving wheel speed _VFO , which is the peripheral speed of the front wheels 60 and 61, is calculated by the following equation (3) in consideration of the slip amount and the road surface condition. Stage as the _{V FO = 1.03 · V + V} K ... (3) where, V _K a road correction amount set in advance corresponding to the corrected longitudinal acceleration G _XF, the value of the correction longitudinal acceleration G _XF increases In this embodiment, the road surface correction amount _VK is obtained from a map such as that shown in FIG. 10 created based on a driving test and the like.

Next, the slip amount s, which is the difference between the vehicle speed V and the target driving wheel speed _VFO , is calculated by the following equation (4) based on the above equations (1) and (3). s = {(V _FL + V _FR ) / 2} −V _FO (4) Then, as shown in the following equation (5), the slip amount s is multiplied by the integral coefficient K _I every sampling cycle of the main timer. An integrated correction torque T _I (in which T _I ≦ 0) is integrated to enhance control stability with respect to the target drive torque T _OS .
Is calculated. T _I = ΣK _I · s _(i) (5) where i is 1 to n.

Similarly, as shown in the following equation (6), the proportional correction torque T _P for reducing the control delay with respect to the target drive torque T _OS proportional to the slip amount s is multiplied by the proportional coefficient K _P. Is calculated. T _P = K _P · s (6) Then, the target drive torque T _OS of the engine 11 is calculated by the following equation (7) using the above equations (2), (5), and (6). T _OS = (T _B −T _I −T _P + T _R ) / (ρ _m · ρ _d ) (7) In the above equation, ρ _m is the speed ratio of the transmission (not shown), and ρ _d is the reduction ratio of the differential gear. It is.

The vehicle 68 is provided with a manual switch (not shown) for the driver to select the slip control. When the driver operates the manual switch to select the slip control, the slip control described below is performed. Perform control operations.

FIG. 1 showing the flow of the slip control process.
As shown in FIG. 1, the TCL 58 first detects the target driving torque T
_{The OS} is calculated, but this calculation is performed independently of the operation of the manual switch.

Next, at S2, the slip control flag F _{S is set.}
It is determined whether or not the flag F _S is set at first.
58 determines in S3 whether the slip amount s of the front wheels 60 and 61 is larger than a preset threshold value, for example, 2 km / h.

[0066] If it is determined that the slip amount s is determined in step S3 is greater than the per hour 2km, TCL 58 determines whether the rate of change G _S of the slip amount s is greater than 0.2g at S4.

[0067] If the slip amount change rate G _S is determined in step S4 is determined to be larger than 0.2 g, and sets in the slip control flag F _S at S5, the slip control flag F _S is set at S6 It is determined again whether or not it has been performed.

If it is determined in step S6 that the slip control flag F _S is being set, then in step S7, the slip drive calculated in advance by the above equation (7) as the target drive torque T _OS of the engine 11 is determined. The target drive torque T _OS for control is adopted.

If it is determined in step S6 that the slip control flag F _S has been reset, the TCL 58 outputs the maximum torque of the engine 11 as the target drive torque T _OS in S8. As a result, the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side, and as a result, the engine 11 generates an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver.

In the step S8, the TCL 58
Outputs the maximum torque of the engine 11 because the ECU 54 always outputs the torque control solenoid valve 46,
The duty ratio of 51 is set to the 0% side, that is, in a direction in which the energization of the torque control solenoid valves 46 and 51 is cut off, so that the engine 11 reliably generates an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver. This is because consideration was given to it.

If it is determined in step S3 that the slip amount s of the front wheels 60 and 61 is smaller than 2 km / h,
Alternatively, in step S4, the slip amount change rate G _S is 0.2.
g, it is determined in S6
And the TCL 58 determines the target drive torque T _OS
In step S8, the ECU 54 outputs the maximum torque of the engine 11 so that the ECU 54
As a result of reducing the duty ratio of the engine 51 to the 0% side, the engine 1
1 generates an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver.

[0072] On the other hand, if the step in the slip control flag F _S of the S2 is when it is determined to have been set, the idle switch 57 is turned on at S9, i.e. throttle valve 15 is in the fully closed state Determine whether or not.

[0073] When it is determined that the idling switch 57 at this step S9 is on, because the driver is not depressing the accelerator pedal 26, and resets the in slip control flag F _S at S10, step S6 Move to

[0074] Further, when the idle switch 57 is determined to be off at step S9, it is determined whether or not has been set again slip control flag F _S at step S6.

When the driver does not operate the manual switch for selecting the slip control, the TCL 58 calculates the target drive torque T _OS for the slip control as described above, and then performs the turning control. The target driving torque of the engine 11 is calculated.

In turning control of the vehicle 68, the TCL5
8 calculates a target lateral acceleration G _YO of the vehicle 68 from the steering shaft turning angle δ _H and the vehicle speed V, and calculates an acceleration in the vehicle longitudinal direction such that the vehicle 68 does not undergo extreme understeering, that is, a target longitudinal acceleration G _XO . It is set based on the target lateral acceleration _GYO . Then, a target driving torque of the engine 11 corresponding to the target longitudinal acceleration G _XO is calculated.

Incidentally, the lateral acceleration G _Y of the vehicle 68 can be actually calculated by using the rear wheel speed difference | V _RL -V _RR |, but by using the steering shaft turning angle δ _H , 68 since it becomes possible to predict the value of the lateral acceleration G _Y acting on, has the advantage of being able to perform a quick control.

However, the steering shaft turning angle δ _H and the vehicle speed V
Thus, merely obtaining the target drive torque of the engine 11 does not reflect the driver's intention at all, and the driver may be dissatisfied with the maneuverability of the vehicle 68. For this reason, it is desirable that the required drive torque _Td of the engine 11 desired by the driver is obtained from the depression amount of the accelerator pedal 26, and the target drive torque of the engine 11 is set in consideration of the required drive torque _Td. . Engine 1 set every 15 milliseconds
When the amount of increase / decrease of the target drive torque of 1 is very large,
Since a shock due to the acceleration and deceleration of the vehicle 68 occurs and the ride quality is reduced, if the amount of increase or decrease in the target drive torque of the engine 11 becomes large enough to cause a decrease in the ride quality of the vehicle 68, It is also necessary to regulate the amount of increase or decrease of the target drive torque.

Further, if the target drive torque of the engine 11 is not changed depending on whether the road surface is a high μ road or a low μ road, for example, while the vehicle is traveling on a low μ road, the target drive torque for the high μ road is
When the vehicle is driven, there is a possibility that the front wheels 60 and 61 may slip and it is impossible to drive safely.
It is desirable to calculate the target drive torque T _OH for the high μ road and the target drive torque T _OL for the low μ road, respectively.

As shown in FIGS. 12 and 13 showing the operation block of the turning control for the high μ road in consideration of the above knowledge, the TCL 58 determines the vehicle speed V from the outputs of the pair of rear wheel rotation sensors 66 and 67. The front wheels 60 and 61 are calculated based on the above equation (1) and based on the detection signal from the steering angle sensor 70.
Is calculated from the following equation (8), and at this time, the target lateral acceleration G _YO of the vehicle 68 is obtained from the following equation (9). δ = δ _H / ρ _H (8) G _YO = δ / ｛l (A + 1 / V ² )｝ (9) where ρ _H is the gear ratio of the steering gear, l is the wheel base of the vehicle 68, and A is the vehicle Is the stability factor.

As is well known, the stability factor A is a value determined by the structure of the suspension of the vehicle 68, the characteristics of the tires, and the like. Specifically, the actual lateral acceleration G _Y generated in the vehicle 68 during a steady circular turn and the steering angle ratio δ _H / δ _HO of the steering shaft 69 at this time (the neutral position δ _{M of the} steering shaft 69)
Figure showing the relationship between the turning angle δ _HO of the steering shaft 69 and the turning angle δ _H of the steering shaft 69 during acceleration in a very low-speed running state in which the lateral acceleration G _Y is close to 0 with reference to It is expressed as a slope of a tangent in a graph as shown in FIG. That is, in a region where the lateral acceleration G _Y is small and the vehicle speed V is not so high, the stability factor A is almost constant (A = 0.002), but the lateral acceleration G _Y is
When it exceeds 0.6 g, the stability factor A sharply increases,
The vehicle 68 will exhibit a very strong tendency to understeer.

From the above, based on FIG. 14, the stability factor A is set to 0.002 or less, and the target lateral acceleration G _{YO of the} vehicle 68 calculated by the equation (9) is obtained. The target drive torque of the engine 11 is controlled so as to be less than 0.6 g.

After the target lateral acceleration G _YO is calculated in this way, the magnitude of the target lateral acceleration G _YO and the vehicle speed V _YO are calculated in advance.
DOO determined from a map stored as shown in FIG. 15 the target longitudinal acceleration G _XO of the vehicle 68 which is set to TCL58 according to the following equation a reference driving torque T _B of the engine 11 by the target longitudinal acceleration G _XO ( Calculate according to 10). T _B = (G _XO · W _b · r + T _L ) / (ρ _m · ρ _d ) (10) where T _L is the road resistance obtained as a function of the lateral acceleration G _Y of the vehicle 68. Road-Load) torque, which is obtained from a map as shown in FIG. 16 in this embodiment.

[0084] Next, in order to determine the adoption ratio of reference driving torque T _B, obtains the correction reference driving torque by multiplying the weighting coefficients α to the reference driving torque T _B. The weighting coefficient α is set empirically by turning the vehicle 68, and a numerical value of about 0.6 is adopted on a high μ road.

[0085] On the other hand, Fig required driving torque T _d to desired driver based on the accelerator opening theta _A detected by the engine speed N _E and an accelerator opening sensor 59 detected by the crank angle sensor 55 17 From the map shown in
Next, the correction required drive torque corresponding to the weighting coefficient α is calculated by multiplying the required drive torque _Td by (1−α).

Therefore, the target drive torque T _OH of the engine 11 is calculated by the following equation (11). T _OH = α · T _B + (1−α) · T _d (11)

The weighting coefficient α is set empirically by turning the vehicle 68, and at the end of the turning, that is, from the vicinity of the exit of the turning circuit, an output torque corresponding to the accelerator pedal depression amount of the driver is obtained. Since the drivability is improved by performing the control, as shown in FIG. 26, FIG. 27, or FIG.

FIG. 26 shows a configuration in which the coefficient α is gradually decreased at a constant rate (inclination) with the elapse of time after the start of control. The configuration shown in FIG. When it is large, decrease the coefficient α slowly,
When the vehicle speed is low, the coefficient α is decreased quickly. In the example shown in FIG. 28, the coefficient α is set to a constant value α ₀ (for example, α ₀ = 1.0) for a while after the control is started, and
It is designed to gradually decrease after a predetermined time has elapsed.

The vehicle 68 is provided with a manual switch (not shown) for the driver to select the turning control for the high μ road, and the driver operates this manual switch to turn the high μ road. Is selected, the turning control operation for a high μ road described below is performed.

The target driving torque T for turning control on the high μ road is as follows.
_As shown in FIGS. 18 and 19 showing the flow of control for determining _OH , the target drive torque T _OH is calculated by the above-described various data detection and calculation processing at H1. It is performed independently of the operation of the switch.

Next, at H2, it is determined whether or not the vehicle 68 is under the turning control on the high μ road, that is, the high-μ road turning control flag F
Determine whether _CH is set. Initially high μ
Since the road turning control is not being performed, the high-μ road turning control flag F
It is determined that _CH is in the reset state, and it is determined in H3 whether the target drive torque T _OH is equal to or less than a preset threshold value, for example, (T _d −2). That is, the target drive torque T _OH can be calculated even when the vehicle 68 is traveling straight, but the value is usually much larger than the driver's required drive torque T _d . However, the required driving torque _Td is
In general, when the vehicle is turning, it becomes small. Therefore, the target driving torque T _OH is set as a start condition of the turning control when the target driving torque T _OH becomes equal to or less than the threshold value (T _d -2).

The reason why the threshold value is set to (T _d -2) is as a hysteresis for preventing control hunting.

If it is determined in step H3 that the target drive torque T _OH is equal to or less than the threshold value (T _d -2), the TCL 58
Determines in H4 whether the idle switch 57 is off.

If it is determined in step H4 that the idle switch 57 is in the OFF state, that is, the accelerator pedal 26 is depressed by the driver, the high-μ road turning control flag _FCH is set in H5. Next, whether the steering angle neutral position learned flag F _H is set at H6, i.e. authenticity of the steering angle δ detected by the steering angle sensor 70 is determined.

[0095] Once at H6 of step determines that the steering angle neutral position learned flag F _H is set, whether the high μ road turning control flag F _CH is set is determined again at H7 .

In the above procedure, the high μ
Since the road turning control flag F _CH is set, H7
In step, it is determined that the high μ road turning control in-progress flag _FCH is set, and the previously calculated value in H8, that is, the target drive torque T _{OH in} the step of H1, is adopted as it is.

On the other hand, if it is determined in step H6 that the steering angle neutral position learned flag F _H is not set, the steering angle δ calculated by the equation (8) is not reliable.
Without using the target drive torque T _OH calculated by equation (11),
The TCL 58 outputs the maximum torque of the engine 11 at H9 as the target drive torque T _OH , whereby the ECU 54 reduces the duty ratio of the solenoid valves 46 and 51 for torque control to the 0% side. An output torque corresponding to the depression amount of the accelerator pedal 26 is generated.

If it is determined in step H3 that the target drive torque T _OH is not equal to or smaller than the threshold value (T _d -2), the control does not shift to the turning control, and the control proceeds from step H6 or H7 to step H9.
The TCL 58 determines the target drive torque T _OH
Output the maximum torque of the engine 11 as
As a result of U54 reducing the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side, the engine 11 generates an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver.

Similarly, when the idle switch 56 is turned on in step H4, that is, when it is determined that the accelerator pedal 26 is not depressed by the driver, the TC
L58 outputs the maximum torque of the engine 11 as the target drive torque T _OH , whereby the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side. The output torque corresponding to the stepping amount of the vehicle is generated, and the process does not shift to the turning control.

If it is determined in step H2 that the high-μ road turning control flag _FCH is set,
At 10, it is determined whether or not the difference ΔT between the currently calculated target drive torque T _OH and the previously calculated target drive torque T _{OH (n−1)} is larger than a preset allowable increase / decrease amount T _K. The increase / decrease allowable amount T _K is a torque change amount that does not cause the occupant to feel the acceleration / deceleration shock of the vehicle 68. For example, when it is desired to suppress the target longitudinal acceleration G _XO of the vehicle 68 to 0.1 g per second,
Using the equation (10), T _K = (0.1 · W _b · r · Δt) / (ρ _m · ρ _d )

The target drive torque T _OH calculated this time in the step H10 and the target drive torque T calculated last time
_{If it} is determined that the difference ΔT from _{OH (n−1)} is not larger than the preset allowable increase / decrease amount T _K , at H11, the target drive torque T _OH and the previously calculated target drive torque T _{OH (n -1)}
Then, it is determined whether or not the difference ΔT is larger than the negative increase / decrease allowable amount T _K.

If it is determined in step H11 that the difference ΔT between the current target driving torque T _OH and the previously calculated target driving torque T _{OH (n−1)} is larger than the negative increase / decrease allowable amount T _K ,
Since the absolute value | ΔT | of the difference between the target drive torque T _OH calculated this time and the target drive torque T _{OH (n−1)} calculated last time is smaller than the increase / decrease allowable amount T _K , the calculated target drive torque this time T _OH is directly used as the value calculated in the step of H8.

In step H11, the target driving torque T _OH calculated this time and the target driving torque T
_If it is determined that the difference ΔT from _{OH (n-1)} is not larger than the negative increase / decrease allowable amount T _K , the current target driving torque T
_OH is corrected by the following equation, and this is adopted as the value calculated in the step of H8. _{T OH = T OH (n-} 1) -T K words, restricting the decrease width by increasing or decreasing tolerance T _K for the target driving torque T _OH previously calculated _(n-1), the output of the engine 11 collected by <br/> This reduces the deceleration shock associated with the reduction of luk.

[0104] On the other hand, it is determined that the difference ΔT between the H10 target driving torque calculated this time in step T _OH and the target driving torque T _OH previously calculated _(n-1) is increased or decreased tolerance T _K or higher Then, at H13, the current target drive torque T _OH is corrected by the following equation, and this is adopted as the calculated value at the step of H8. _{T OH = T OH (n-} 1) + T K In other words, even if the increase in the output torque as in the above-mentioned output torque reduction, the target drive currently calculated torque T _OH and the target driving torque T _OH previously calculated ₍ If _{the n-1)} difference between ΔT exceeds the decrease tolerance T _K restricts gains at decreasing tolerance T _K for the target driving torque T _OH previously calculated _(n-1), the output of the engine 11 The acceleration shock accompanying the increase in torque is reduced.

As described above, the steering shaft turning angle δ _H and the target longitudinal acceleration G when the amount of increase or decrease of the target drive torque T _OH is regulated.
The actual change state between the longitudinal acceleration G _X and _XO and the target driving torque T _OH as shown in FIG. 20 indicated by the dashed line, than the case shown by the solid line that did not restrict the decrease amount of the target driving torque T _OH, actual change of the longitudinal acceleration G _X of becomes smooth, it can be seen that the acceleration or deceleration shock is eliminated.

When the target drive torque T _OH is set as described above, the TCL 58 determines in H14 whether the target drive torque T _OH is larger than the driver's required drive torque T _d .

If the high-μ road turning control flag _FCH is set, the target drive torque T _OH is not larger than the driver's required drive torque _Td , and the idle switch 57 is turned on at H15. It is determined whether it is in the state.

If it is determined in step H15 that the idle switch 57 is not in the ON state, it is determined that the turning control is required, and the process proceeds to step H6.

If it is determined in step H14 that the target drive torque T _OH is larger than the driver's required drive torque T _d , it means that the vehicle 68 has completed turning and the TCL 58 is set to H16. Resets the high-μ road turning control in-progress flag _FCH . Similarly, if it is determined in step H15 that the idle switch 57 is in the on state, the accelerator pedal 26 is not depressed, so the flow proceeds to step H16 and the high μ road turning control flag F Reset _CH .

At H16, the high-μ road turning control flag F
_{When the CH} is reset, the TCL 58 becomes the target driving torque T
The maximum torque of the engine 11 is output as _OH at H9, whereby the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side. As a result, the driver of the engine 11 depresses the accelerator pedal 26. Generates an output torque corresponding to.

In this embodiment, the target driving torque T _OH of the engine 11 is calculated from the target lateral acceleration G _YO of the vehicle 68, and the target driving torque T _OH and a preset threshold value (T _d -2).
It is determined that the turning control is started when the target driving torque T _OH is equal to or less than the threshold value (T _d −2). However, the target lateral acceleration G _YO of the vehicle 68 and a preset reference value, For example, the target lateral acceleration G is directly compared with 0.6 g.
_{When YO} becomes equal to or more than the reference value of 0.6 g, it is of course possible to determine to start turning control.

The target drive torque T for the high μ road turning control
After calculating _OH , the TCL 58 calculates a target drive torque T _OL for low-μ road turning control as follows.

On the low μ road, the actual lateral acceleration G _Y
Since the direction of the target lateral acceleration G _YO is greater than, to determine whether the target lateral acceleration G _YO is greater than a predetermined threshold value, when the target lateral acceleration G _YO is greater than this threshold It is determined that the vehicle 68 is traveling on the low μ road, and the turning control may be performed as necessary.

As shown in FIG. 21 and FIG. 22 showing the operation block of the turning control for the low μ road, the steering shaft turning angle δ _H
From the vehicle speed V and the target lateral acceleration G _YO , the target lateral acceleration G _YO is obtained by the above equation (9).
005 is adopted.

Next, a target longitudinal acceleration G _XO is obtained from the target lateral acceleration G _YO and the vehicle speed V. In this embodiment, the target longitudinal acceleration G _XO is read from a map as shown in FIG. This map represents a target longitudinal acceleration G _XO that enables the vehicle 68 to travel safely according to the magnitude of the target lateral acceleration G _YO in association with the vehicle speed V, and is set based on the test driving results and the like. Is done.

[0116] Then, it calculates a reference driving torque T _B based on the target longitudinal acceleration G _XO by the equation (10),
Or asking a map determining the adoption rate of the reference driving torque T _B. In this case, the weighting coefficient α is larger than the coefficient α for the high μ road and is set, for example, to α = 0.8. This is because the vehicle can turn safely and reliably on a low μ road with high reliability.

[0117] On the other hand, the requested driving torque T _d of the driver, the target that is calculated during the calculation work for high μ road is employed as it is, thus taking into account the reference driving torque T _B in required driving torque T _d The driving torque T _OL is calculated by the following equation (12) similar to the above equation (11). T _OL = α · T _B + (1−α) · T _d (12)

The vehicle 68 is provided with a manual switch (not shown) for the driver to select the turning control for the low μ road, and the driver operates the manual switch to operate the turning control for the low μ road. When is selected, the turning control operation for a low μ road described below is performed.

The target drive torque T for the low μ road turning control is as follows.
24 and 25 showing the flow of control for determining _OL .
As shown in (1), the target drive torque T _OL is calculated by detecting and calculating various data in L1 as described above, but this operation is performed regardless of the operation of the manual switch.

Next, at L2, it is determined whether or not the vehicle 68 is under the turning control on the low μ road, that is, the low μ road turning control flag F
Determine if _CL is set. Initially low μ
Since the road turning control is not being performed, the low μ road turning control flag F
It is determined that the _CL is in the reset state, and at L3, the rear wheels 64,
0 to the actual lateral acceleration G _Y calculated by the rotational difference of 65.
Target lateral acceleration whether G _YO is greater than a predetermined threshold value by adding 05G, i.e. since the direction of the target lateral acceleration G _YO than the actual lateral acceleration G _Y is a low μ road is a large value, the target It is determined whether or not the lateral acceleration G _YO is greater than this threshold. If the target lateral acceleration G _YO is greater than the threshold, it is determined that the vehicle 68 is traveling on a low μ road.
Note that the actual lateral acceleration G _Y generated on the vehicle 68, the peripheral speed difference between the rear wheels | is calculated as the following equation from the vehicle speed _{V (13) | V RL -V} RR. _{G Y = (| V RL -V} RR | · V) / (3.6 2 · b · g) ... (13) where, b is the tread of the rear wheels 64 and 65.

At step L3, the target lateral acceleration G _YO
Is larger than the threshold value (G _Y +0.05 g), that is, the vehicle 68 is turning on a low μ road, the TCL 58 counts up a low μ road timer (not shown) built in the TCL 58 at L4. However, the count time of the low μ road timer is, for example, 5 milliseconds. Until the counting of the low μ road timer is completed, the process proceeds to steps after L6 described later, and the target lateral acceleration G _YO according to the expression (9) and the actual lateral acceleration according to the expression (13) are determined every 15 milliseconds. The acceleration _GY is calculated and the operation of determining L3 is repeated.

That is, the timer for the low μ road is counted up.
And until the elapse of 0.5 seconds, the process proceeds to L8 step through step L6, L7, TCL 58 outputs a maximum torque of the engine 11 as the target driving torque T _OL, thereby ECU54 torque control the duty ratio of the use electromagnetic valves 46 and 51 results in a reduction to 0% side, leaving the engine 11 in accordance with the depression amount of the accelerator pedal 26 by the driver
Generates force torque.

When the target lateral acceleration G _YO is equal to the threshold value (G _Y +0.05)
g) If the larger state does not continue for 0.5 seconds, TCL5
8 judges that the vehicle 68 is not running on the low μ road,
To clear the count of the timer for low μ road and
Go to step.

The target lateral acceleration G _YO is equal to the threshold value (G _Y +0.05).
g) If the larger state continues for 0.5 second, it is determined at L10 whether or not the idle switch 57 is off, and it is determined that the idle switch 57 is on, that is, the accelerator pedal 26 is not depressed by the driver. the case, the low μ count low μ road timer is cleared at L9 without migrating to the turning control of the road, the engine as a TCL58 proceeds to step L6~L8 target driving torque T _OL As a result, the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side. As a result, the engine 11 outputs an output torque corresponding to the depression amount of the accelerator pedal 26 by the driver. Occur.

If it is determined in step L10 that the idle switch 57 is in the off state, that is, the accelerator pedal 26 is depressed by the driver, a low μ road turning control flag _FCL is set in L11. Next, L6
Steering angle neutral position learned flag F _H is whether it is set, i.e., the authenticity of the steering angle δ detected by the steering angle sensor 70 is determined by.

[0126] At L6 step determines that the steering angle neutral position learned flag F _H is set, whether the low μ road turning control flag F _CL is set is determined again at L7 . Here, if the low μ road turning control in-progress flag F _CL is set in the step of L11, L
Step in the previous calculated value of 12, that is, the target driving torque T _OL in L1 of the step is employed as it is.

[0127] When the steering angle neutral position learned flag F _H determined in step L6 is judged not to be set, since there is no credibility of the steering angle δ proceeds to L8 step, it is calculated previously at L1 and (12) does not employ a target driving torque T _OL of formula, TCL 58 outputs a maximum torque of the engine 11 as the target driving torque T _OL, thereby ECU54 is the duty ratio of the torque control solenoid valve 46 and 51 0 %, The engine 11 is controlled by the driver to operate the accelerator pedal 26.
An output torque is generated in accordance with the amount of depression.

On the other hand, if it is determined in step L2 that the low μ road turning control in-progress flag _FCL is set, the flow shifts to step L13.

In steps L13 to L16, the high μ
As in the case of road turning control, determining whether or not the difference ΔT between a currently calculated target driving torque T _OL and the target driving torque T _OL previously calculated _(n-1) is larger than the increase or decrease the allowable amount T _K And
In either case of increase or decrease, if this is within the allowable change amount T _K , the target drive torque T _OL calculated this time is directly used as L12.
When ΔT exceeds the allowable change amount T _K , the target drive torque T _OL is regulated by the allowable change amount T _K.

That is, when the target drive torque T _OL is decreased, the current target drive torque T _OL is corrected to T _OL = T _{OL (n-1)} -T _K in L15, and this is corrected in step L12. It is adopted as the calculated value in. Conversely, in the case of increasing the target driving torque T _OL is calculated at this target driving torque T _OL is corrected to _{T OL = T OL (n-} 1) + T K, which L12 steps at L16 Adopt as a value.

When the target drive torque T _OL is set as described above, the TCL 58 determines at L17 whether the target drive torque T _OL is larger than the driver's required drive torque T _d .

If the low-μ road turning control flag F _CL is set, the target driving torque T _OL is not larger than the required driving torque T _d , so the flow shifts to step L9 for low-μ road turning control. Clear the timer count to L6, L7
Proceeds to the step where the steering angle neutral position learned flag F _H is determined to be set, when it is further determined that the low-μ road turning control flag F _CL is set, L
The calculated value adopted in step 1 or L15 or L16 is selected as the target drive torque _TOL for low-μ road turning control.

Even if it is determined in the step L17 that the target drive torque T _OL is larger than the driver's required drive torque T _{d, the} steering shaft turning angle δ _H is less than 20 degrees, for example, in the next L18. If it is determined that the vehicle 68
Is turning, so that the turning control is continued.

At step L17, it is determined that the target drive torque T _OL is larger than the driver's required drive torque T _d , and at L18, it is determined that the steering shaft turning angle δ _H is less than 20 degrees, for example. In this case, it means that the turning of the vehicle 68 has ended, so the TCL 58 resets the low μ road turning control in-progress flag F _CL at L19.

When the low μ road turning control flag F _CL is reset at the step of L19, the timer for the low μ road does not need to be counted. , L7.
Since the low-μ road turning control flag F _CL at L7 step is determined to be in the reset state, the engine 1 as TCL58 the target drive torque TOL proceeds to L8 step
As a result, the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side. As a result, the engine 11 outputs an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver. Occur.

By the way, if the circuit ends at a constant curvature, there is no problem even if the weighting coefficient α is set to 0 after the lapse of a certain time as described above, but it is rather advantageous in terms of improving drivability. If the circuit has a sharp curve following a gentle curve as shown in FIG. 31, the output control cannot be performed if the weighting coefficient α has already become zero.

Therefore, when the steering wheel is turned further after coming into a sharp curve, this is detected and the weighting coefficient α is increased.

FIG. 32 shows a flow for obtaining the increase α _{1 of the} coefficient α. This calculation is performed in steps H1 and L1 in the flowcharts shown in FIGS. 18 and 19 and FIGS. 24 and 25.

First, at step J1, it is determined whether or not the current rotation angle of the steering wheel ₍ the turning angle of the steering shaft 69) δ _{H (n)} is larger than the previous rotation angle δ _{H (n-1)} of the steering wheel. Is done.

The current steering wheel rotation angle δ _{H (n)}
If who is smaller than the previous one, if that is where it is determined NO, and since the turning path is gradually state will become straight road, the coefficient increment alpha ₁ in step J8 is zero.

The current steering wheel rotation angle δ _{H (n)}
Is larger than the previous one δH _(n-1) , that is, if it is determined that the steering wheel is being turned further, then at step J5, the difference in rotation angle of the steering wheel is determined. It is increased alpha ₁ weighting coefficient alpha is calculated by multiplying the coefficient K [alpha '.

When the coefficient increment α ₁ is obtained, the following J3
In this step, the weighting coefficient α _(n) to be adopted this time is obtained from the following equation. _{α (n) = α (n} -1) -Kα + α 1

Here, Kα is a decreasing coefficient of the coefficient α for each sampling time, and corresponds to the slope of the change line of the coefficient α shown in FIGS.

Next, in step J4, it is determined whether or not the obtained current weighting coefficient α _(n) is larger than 0.
If it is smaller than 0, α _(n) cannot actually be made smaller than 0, so α _(n) = 0 is determined in the step of J5.

In step J4, the current weighting coefficient α
If it is determined that _(n) is greater than 0, it is determined in step J6 whether α _(n) is greater than the initial value α ₀ . When the coefficient alpha _(n) is greater than the initial value alpha _0, since not be larger than the initial value alpha _0, to determine the α _(n) = α ₀ in step J7.

In step J6, the current weighting coefficient α _(n)
If but it is determined that the initial value alpha ₀ less than the value determined alpha _(n), the correction reference driving torque _{(α (n)} ·
T _B ).

FIG. 33 shows changes in the weighting coefficient α _{(n) in} a diagram. A circuit 100 as shown in FIG.
In FIG. 7, when the turning control is started at the position A and the weighting coefficient α _(n) gradually decreases to 0, the vehicle approaches a sharp curve at the position B and the driver turns the steering wheel greatly, as shown in FIG. ) by the coefficient increment alpha ₁ as shown in alpha
_(n) rises again and the output torque is reduced.

Therefore, even if the vehicle is approaching a steeper curve while turning control, the vehicle will not be unable to turn,
Stable turning can be achieved.

The amount of additional turning of the steering wheel can also be detected by the angular speed of the steering wheel. As shown in FIG. 34, the angular speed of the steering wheel (dt / d | δ _H |) and the coefficient increase α ₁
Is determined in advance to map the relationship between, it is to to obtain the reduction factor alpha ₁ corresponding to the angular velocity. This reading
In the flowchart shown in FIG. 32, step J2
Made in.

Note that, in the above-described arithmetic processing method, the engine 1
To prevent deceleration shock due to variations in the first rapid output torque, target driving torque T _OH, the target driving torque T _OH by decreasing tolerance T _K when calculating the T _OL, T
_{The OL} is regulated, but this regulation is
It may be performed for _XO . Assuming that the permissible amount of change in this case is G _K , the target longitudinal acceleration G at n times
The calculation process of _{XO (n)} is shown below.

The sampling time of the main timer is set to 1
Change in target longitudinal acceleration G _XO as 5 ms, 0.1 g / sec
When it is desired to suppress the value, G _K = 0.1 · Δt.

This low μ road turning control target drive torque T
After calculating the _OL , the TCL 58 selects an optimal final target drive torque T _O from these three target drive torques T _OS , T _OH , and T _OL , and outputs this to the ECU 54. In this case, in consideration of the running safety of the vehicle 68, the target drive torque having the smallest numerical value is output with priority. However, since the target drive torque T _OS for the slip control is generally always smaller than the target drive torque T _OL for the low μ road turning control, the slip control, the low μ road turning control, and the high μ road turning are generally used. What is necessary is just to select the final target drive torque T _O in order of control.

As shown in FIG. 29 showing the flow of this processing, the three target drive torques T _OS , T
After calculating _OH and T _OL , it is determined in M12 whether the slip control flag F _S is set.

[0154] If step at the slip control flag F _S of the M12 is determined to have been set, TC
L58 selects a target drive torque T _OS for slip control in M13 as the final target drive torque T _O , and sets this to EC
Output to U54.

[0155] to ECU54 is, the engine speed N _E and the engine 1
1 with the output torque of 1 as a parameter
A map for obtaining _T is stored. At M14, the ECU 54 uses this map to determine the current engine speed N _E.
And the target throttle opening θ _TO corresponding to the target drive torque T _OS . Next, the ECU 54 calculates the deviation between the target throttle opening θ _TO and the actual throttle opening θ _T output from the throttle opening sensor 56, and calculates the duty ratio of the pair of torque control solenoid valves 46 and 51 by the deviation. And the torque control solenoid valves 46 and 5
Apply current to the solenoids of the plungers 47 and 52
Control is performed so that the actual throttle opening θ _T is reduced to the target value θ _TO by the operation of the actuator 36.

If it is determined in step M12 that the slip control flag F _S has not been set, then M
At 15, it is determined whether or not the low μ road turning control flag _FCL is set.

If it is determined in step M15 that the low-μ road turning control flag F _CL is set, the target driving torque T _OL for low-μ road turning control is set to M16 as the final target driving torque T _O. And the process proceeds to step M14.

If it is determined in step M15 that the low μ road turning control in-progress flag F _CL is not set,
In M17, it is determined whether or not the high μ road turning control in-progress flag _FCH is set.

If it is determined in step M17 that the high μ road turning control flag _FCH is set, the target driving torque T _OH for high μ road turning control is set as the final target driving torque T _O. Is selected in M18, and the process proceeds to M14.

[0160] On the other hand, if the high-μ road turning control flag F _CH at the M17 steps are determined not to be set, TCL 58 outputs a maximum torque of the engine 11 as a final target drive torque T _O, which As a result, the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side, and as a result, the engine 11 generates an output torque corresponding to the amount of depression of the accelerator pedal 26 by the driver. In this case, in this embodiment, a pair of torque control solenoid valves 46,
The duty ratio of 51 is not unconditionally set to 0%, and the ECU 5
4 compares the actual accelerator opening θ _A with the maximum throttle opening restriction value, and when the accelerator opening θ _A exceeds the maximum throttle opening restriction value, the accelerator opening θ _A becomes the maximum throttle opening restriction value. The duty ratio of the pair of torque control solenoid valves 46 and 51 is determined so that
7 and 52 are driven. The maximum throttle opening regulation value as a function of engine speed N _E, a value (e.g., 2000
Although in rpm) or more is set to the fully closed state or the vicinity thereof, which follows in the region of low rotation speed, set to gradually become smaller until several tens% of the opening with decreasing engine speed N _E I have.

The reason for restricting the throttle opening θ _T is to increase the responsiveness of control when the TCL 58 determines that the output torque of the engine 11 needs to be reduced. That is, the current design policy of the vehicle 68 is:
In order to improve the acceleration and the maximum output of the vehicle 68, the bore diameter (cross-sectional area of the passage) of the throttle body 16 tends to be extremely large. When the engine 11 is in a low rotation region, the throttle opening θ _T becomes small. The intake air amount is saturated at about several tens%. Therefore, rather than setting the throttle opening θ _T to a fully opened state or its vicinity in accordance with the depression amount of the accelerator pedal 26, the throttle opening degree θ _T is regulated to a predetermined position, so that the target when the output torque reduction command is issued is issued. This is because the deviation between the throttle opening θ _TO and the actual throttle opening θ _T is reduced, and the target throttle opening θ _TO can be quickly reduced.

In the above-described embodiment, two kinds of target drive torques for turning control, that is, a high μ road and a low μ road, are calculated. A corresponding target drive torque for turning control may be calculated, and a final target drive torque may be selected from these target drive torques.

Conversely, one type of target drive torque T _OC for turning control is calculated, and during slip control, the target drive torque T _OS for slip control is used as the target drive torque T _OC for turn control. Is generally always smaller than
Naturally, it is also possible to select the target drive torque T _OS for the slip control _prior to the target drive torque T _OC for the turning control.

As shown in FIG. 30 showing the flow of the processing of another embodiment according to the present invention, a target drive torque T _OS for slip control and a target drive torque T _OC for turning control are set at M21. After calculating by the same method as described above, M
It determines whether the slip control flag F _S is set at 22.

If it is determined in step M22 that the slip control flag F _S has been set, the target drive torque T _OS for slip control is selected in M23 as the final target drive torque T _O. And E at M24
CU54 this target throttle opening theta _TO corresponding to the target driving torque T _OS and the current engine speed N _E ECU 5
4, the deviation between the target throttle opening θ _TO and the actual throttle opening θ _T output from the throttle opening sensor 56 is determined, and the deviation of the pair of torque control solenoid valves 46 and 51 is determined. The duty ratio is set to a value commensurate with the above-mentioned deviation, a current flows through the solenoids of the plungers 47 and 52 of the torque control solenoid valves 46 and 51, and the actual throttle opening θ _T
Is controlled to fall to the target value θ _TO .

If it is determined in step M22 that the slip control flag F _S is not set,
At 25, it is determined whether or not the turning control flag F _C is set.

If it is determined in step M25 that the turning control flag F _C is set, the target driving torque T _OC for turning control is set as the final target driving torque T _O.
Is selected in M26, and the process proceeds to step M24.

On the other hand, if it is determined in step M25 that the turning control flag F _C has not been set,
The TCL 58 outputs the maximum torque of the engine 11 as the final target drive torque T _O , whereby the ECU 54 reduces the duty ratio of the torque control solenoid valves 46 and 51 to the 0% side. 26
An output torque is generated in accordance with the amount of depression.

[0169]

According to the output control apparatus for a vehicle according to the present invention, the magnitude of the lateral acceleration generated when the vehicle turns is calculated based on the detection signals from the steering angle sensor and the vehicle speed sensor. Since the output torque of the engine is reduced according to the magnitude, the magnitude of the lateral acceleration can be calculated more quickly than the conventional method of detecting the magnitude of the lateral acceleration based on the yaw rate or the like actually generated in the vehicle. Can be estimated. As a result, there is almost no control delay during turning,
The lateral acceleration of the vehicle can be appropriately suppressed, and the vehicle can safely and reliably run through the circuit. Also, by using this output control device, it is also possible to reduce shocks and the like during shifting in the automatic transmission. In addition, since the required driving torque of the driver is taken into consideration based on the detection signals from the rotation speed sensor and the accelerator opening sensor, the drivability of the turning traveling is improved. Furthermore, since the amount of turning of the steering wheel is detected and the amount of reference drive torque adopted is changed, it is possible to cope with a case where the vehicle approaches a sharp curve after the end of turning, that is, the output torque is reduced. Easy and reliable turning can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an engine control system of an embodiment of a vehicle output control device according to the present invention.

FIG. 2 is a conceptual diagram thereof.

FIG. 3 is a sectional view showing a drive mechanism of the throttle valve.

FIG. 4 is a flowchart showing an overall flow of the control.

FIG. 5 is a flowchart illustrating a flow of neutral position learning correction control of the steering shaft.

FIG. 6 is a flowchart illustrating a flow of neutral position learning correction control of the steering shaft.

FIG. 7 is a graph illustrating an example of a correction state of a learning value when a neutral position of a steering shaft is corrected.

FIG. 8 is a graph showing a relationship between a coefficient of friction between a tire and a road surface and a slip ratio of the tire.

FIG. 9 is a map showing a relationship between vehicle speed and running resistance.

FIG. 10 is a map showing a relationship between a corrected longitudinal acceleration and a speed correction amount.

FIG. 11 is a flowchart illustrating a flow of slip control.

FIG. 12 is a block diagram illustrating a procedure for calculating a target drive torque for a high μ road.

FIG. 13 is a block diagram illustrating a procedure for calculating a target driving torque for a high μ road.

FIG. 14 is a graph illustrating a relationship between a lateral acceleration and a steering angle ratio for explaining a stability factor.

FIG. 15 is a map showing a relationship between a target lateral acceleration, a target longitudinal acceleration, and a vehicle speed.

FIG. 16 is a map showing a relationship between lateral acceleration and road load torque.

FIG. 17 is a map showing a relationship among an engine speed, an accelerator opening, and a required drive torque.

FIG. 18 is a flowchart illustrating a flow of a turning control for a high μ road.

FIG. 19 is a flowchart illustrating a flow of a turning control for a high μ road.

FIG. 20 is a graph showing a relationship among a steering shaft turning angle, a target drive torque, and a longitudinal acceleration.

FIG. 21 is a block diagram illustrating a procedure for calculating a target driving torque for a low μ road.

FIG. 22 is a block diagram illustrating a procedure for calculating a target drive torque for a low μ road.

FIG. 23 is a map showing a relationship between a target lateral acceleration, a target longitudinal acceleration, and a vehicle speed.

FIG. 24 is a flowchart showing a flow of a turning control for a low μ road.

FIG. 25 is a flowchart showing a flow of a turning control for a low μ road.

FIG. 26 is a graph showing the relationship between the time after the start of control and the weighting coefficient.

FIG. 27 is a graph showing a relationship between a vehicle speed and a weighting coefficient.

FIG. 28 is a graph showing the relationship between the time after the start of control and the weighting coefficient.

FIG. 29 is a flowchart illustrating an example of an operation of selecting a final target torque.

FIG. 30 is a flowchart illustrating another example of the operation of selecting the final target torque.

FIG. 31 is a schematic diagram of an example of a circuit.

FIG. 32 is a flowchart of calculating a weighting coefficient increment.

FIG. 33 is a diagram showing changes in a weighting coefficient, a steering wheel rotation angle, and the like.

FIG. 34 is a map showing a coefficient increase.

[Explanation of symbols]

11 is an engine, 12 is a combustion chamber, 13 is an intake pipe, 14 is an intake passage, 15 is a throttle valve, 17 is a throttle shaft, 18
Is an accelerator lever, 19 is a throttle lever, 26 is an accelerator pedal, 27 is a cable, 29 is a claw, 30 is a stopper, 36 is an actuator, 38 is a control rod, 42 is a connection pipe, 43 is a vacuum tank, and 44 is a non-return. valve,
45 and 50 are piping, 46 and 51 are torque control solenoid valves,
54 is an ECU, 55 is a crank angle sensor, 56 is a throttle opening sensor, 57 is an idle switch, 58 is a TC
L and 59 are accelerator opening sensors, 60 and 61 are front wheels, 6
2, 63 are front wheel rotation sensors, 64, 65 are rear wheels, 66,
67 is a rear wheel rotation sensor, 68 is a vehicle, 69 is a steering shaft, 7
0 is a steering angle sensor, 71 is a communication cable. Also, A
Is a stability factor, F _H is a steering angle neutral position learned flag, F _S is a slip control flag, F _CH is a high μ road turning control flag, F _CL is a low μ road turning control flag, F F
_C is a turning control flag, G _XO is target longitudinal acceleration, G _X is longitudinal acceleration, G _Y is lateral acceleration, G _YO is target lateral acceleration, g
Is the gravitational acceleration, T _OS is the target drive torque for slip control,
T _OH high μ road target drive torque, T _OL is low μ road target drive torque, T _OC is turning control target driving torque, T _O is the final target drive torque, T _B is the reference driving torque, T _d is required driving torque, V is the vehicle speed, s is slip, theta _a is the accelerator opening, theta _T is the throttle opening degree, theta _tO the target throttle opening degree, [delta] is a front wheel steering angle, [delta] _H is the turning angle of the steering shaft , the [delta] _M is a steering shaft neutral position.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Yoshida 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Masayoshi Ito 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Keiji Isoda 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Akio Shigehara 5-33-8 Shiba, Minato-ku, Tokyo No. Mitsubishi Motors Corporation (72) Inventor Hiroo Yuasa 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) References JP-A-60-209640 (JP, A) JP-A-61-253228 (JP, A) JP-A-2-27124 (JP, A)

Claims (1)

(57) [Claims] 1. A torque control means for reducing an output torque of an engine independently of a driver's operation, a steering angle sensor for detecting a turning angle of a steering shaft, and a vehicle speed sensor for detecting a speed of a vehicle. A rotation speed sensor that detects the rotation speed of the engine, an accelerator opening sensor that detects an accelerator opening, and calculates the lateral acceleration of the vehicle based on detection signals from the steering angle sensor and the vehicle speed sensor, and A reference drive torque corresponding to the magnitude of the lateral acceleration is calculated, and the ratio of adoption of the reference drive torque is calculated and used as a corrected reference drive torque. The required drive torque is determined by calculating the required drive torque, and the ratio of adoption of the required drive torque is determined as a corrected required drive torque. It calculates a torque calculation unit for calculating a target drive torque by changing the adoption ratio of the reference driving torque and the required driving torque is further according to the increase amount of the steering shaft turning angle corresponding to the turning-increasing amount of the steering wheel,
An electronic control unit for controlling the torque control means so that an output torque of the engine becomes a target drive torque.