JPH06323172A - Output control device for vehicle - Google Patents

Abstract

PURPOSE:To satisfactorily obtain a car speed for applying an output control device decreasing an engine output for preventing the generation of a slip to a vehicle of four-wheel drive system. CONSTITUTION:In an estimated car speed arithmetic part 304 switch lengthwise acceleration GXSW in accordance with lengthwise acceleration GX is applied to a formula (A) to obtain an estimated car speed VB, and in a reference wheel speed selecting part 306, a reference wheel speed V3, which is a wheel rotational speed in the third from the highest, is selected. In a comparator part 309, reference wheel acceleration G3f is compared with lengthwise acceleration GXf in a formula (B), and in a comparator part 310, the estimated car speed VB is compared with the reference wheel speed V3 in a formula (C). In a car speed selecting output part 305, a car speed V is switched from the reference wheel speed V3 to the estimated car speed VB, when realized the formula (B), and the car speed V is returned back to the estimated car speed when realized the formula (C). Here is increased alpha when a steering shaft turn angle deltaH is increased to 180 deg. or more. In this way, the car speed is prevented from being easily switched to the estimated car speed VB at the time of turning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel drive type vehicle in which the drive torque of the engine is rapidly reduced in accordance with the slip amount when the vehicle is accelerating, etc., so that the vehicle can travel safely. The present invention relates to a vehicle output control device.

[0002]

2. Description of the Related Art A two-wheel drive type (2WD) vehicle starts or runs on a road surface having a low friction coefficient, such as a snowy road or an icy road, where the condition of the road surface changes suddenly while the vehicle is running. If so, the drive wheels may idle. In such a case, it is very difficult for even a skilled person to adjust the amount of depression of the accelerator pedal and delicately control the output of the engine so that the drive wheel does not idle.

From the above, when the idling state of the drive wheels is detected and the idling of the drive wheels occurs, the output of the engine is forcibly reduced regardless of the depression amount of the accelerator pedal by the driver. An output control device configured to do so has been considered. Then, it has been announced that the driver can select the traveling using the output control device and the ordinary traveling in which the output of the engine is controlled according to the depression amount of the accelerator pedal, as required. .

Among those related to the output control of the vehicle based on such a viewpoint, the conventionally known ones are:
You can list the following: That is, first, the traveling speed of the vehicle (hereinafter, referred to as vehicle speed) and the rotational speed of the drive wheels are detected, and the difference between them is regarded as the slip amount of the drive wheels. Next, subtract the feedback correction torque calculated based on the slip amount of the driving wheels from the reference drive torque calculated based on the acceleration in the longitudinal direction of the vehicle (hereinafter, referred to as longitudinal acceleration). The target drive torque of the engine. Then, the opening degree of the throttle valve, the ignition timing, etc. are controlled so that the drive torque of the engine becomes the target drive torque.

As a torque reducing means for reducing the drive 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. As a more special one, it is possible to adopt a configuration in which the compression ratio of the engine is lowered.

[0006]

The above-mentioned conventional "vehicle output control device" has been applied to a 2WD vehicle. In a four-wheel drive type (4WD) vehicle, all four wheels are rotationally driven, so the "vehicle output control device" applied to a 2WD vehicle cannot be used as it is.

That is, in the conventional "vehicle output control device", the difference between the vehicle speed and the rotational speed (peripheral speed) of the drive wheels is regarded as the slip amount of the drive wheels. Then, the drive torque of the engine is reduced according to the slip amount. By doing so, slipping of the drive wheels on slippery roads such as snowy roads and frozen roads is suppressed, and starting acceleration performance and steering stability are secured.

In a 2WD vehicle, the rotational speed of the non-driving wheels (rear wheels) can be regarded as the vehicle speed. The rotation speed of the drive wheels was calculated from the average of the rotation speeds of the two drive wheels. However, in a 4WD vehicle, all four wheels are driven to rotate,
The problem is how to handle the "vehicle speed" and the "driving wheel rotation speed".

In view of the above situation, it is an object of the present invention to provide a vehicle output control device which is effective when applied to a 4WD vehicle. Even in the case of a 4WD vehicle, slippage may occur due to higher engine output and tightened regulations on spiked tires. Therefore, the inventor of the present application
The D vehicle also adopted the "vehicle output control device" to suppress wheel slip.

[0010]

The structure of the present invention for solving the above problems reduces the drive torque of the engine mounted on the vehicle independently of the operation by the driver who drives the four-wheel drive type vehicle. A torque reducing means, a longitudinal acceleration detecting means for detecting longitudinal acceleration of the vehicle, and a reference driving torque setting for setting a reference driving torque as a reference of the engine based on the longitudinal acceleration detected by the longitudinal acceleration detecting means. Means, a vehicle speed calculating means for calculating the traveling speed of the vehicle based on the longitudinal acceleration, the turning angle of the steering shaft, and the rotational speeds of the wheels, an average of a plurality of speeds of the vehicle traveling speed and the rotational speeds of the wheels. Target drive torque setting means that regards a difference from the speed as a slip amount, obtains a correction torque based on the slip amount, and further sets a target drive torque obtained by subtracting the correction torque from the reference drive torque. A vehicle output control device having an electronic control unit that controls the operation of the torque reduction means so that the drive torque of the engine becomes the target drive torque, wherein the vehicle speed calculation means is (1) An estimated vehicle speed calculation unit that calculates the estimated vehicle speed based on the longitudinal acceleration, and (2) a reference wheel speed selection unit that outputs the predetermined one of the rotation speeds of each wheel from the earliest as the reference wheel speed, and (3) The vehicle speed selection output unit that selects one of the estimated vehicle speed and the reference wheel speed and outputs it as the vehicle speed, and (4) the reference wheel acceleration that is the differentiation of the reference wheel speed is greater than the value obtained by adding the comparison variable to the longitudinal acceleration. And a first comparison unit that switches the vehicle speed at the vehicle speed selection output unit from the reference wheel speed to the estimated vehicle speed,
(5) When the estimated vehicle speed becomes higher than the reference wheel speed, the vehicle speed selection output section includes a second comparing section for returning the vehicle speed from the estimated vehicle speed to the reference wheel speed. In the section, the comparison variable is large when the turning angle of the steering shaft is smaller than a predetermined angle and larger than the predetermined angle.

[0011]

As described above, in the 4WD vehicle, how to obtain the "driving wheel rotation speed" and the "vehicle speed" becomes a problem. Therefore, although the details will be described later, since the inventor of the present application applies the “vehicle output control device” to a 4WD vehicle, the “driving wheel rotation speed” is an average of the rotation speeds of a plurality of wheels, specifically We decided to use the average of the rotational speeds of the fastest wheel and the next fastest wheel. When the third wheel from the faster side is used as the reference wheel and it is determined that there is no slip of the reference wheel (this determination method will be described later), the rotation speed of the reference wheel is regarded as the vehicle speed, and the slip of the reference wheel is considered to have occurred. In this case, the vehicle speed is estimated and calculated from the rotation speed of the reference wheel and the acceleration sensor signal when the slip occurs. Of the four wheels, the wheel that is closest to the vehicle speed during the occurrence of slip is the slowest wheel (fourth from the fastest), so it is possible to use the fourth wheel from the fastest as the reference wheel. Although the accuracy tends to be slightly inferior in consideration of a failure such as disconnection of the wheel speed sensor, the vehicle speed is determined using the third wheel as a reference vehicle.

Further, since the differential value of the rotational speed of the reference wheel becomes larger than the value (longitudinal acceleration + variable) obtained based on the acceleration sensor signal, it is considered that the reference wheel slips. On the contrary, when the vehicle speed obtained by the estimation calculation based on the acceleration sensor signal becomes higher than the rotation speed of the reference wheel, it is considered that the slip of the reference wheel has subsided.

Further, a correction is made during turning.
That is, the rotation speed of the wheels is easily disturbed during turning, and the mode in which the rotation speed of the reference wheel is regarded as the vehicle speed is easily changed to the mode in which the vehicle speed is estimated and calculated based on the acceleration sensor signal. At this time, during turning, the acceleration sensor signal value tends to be smaller than the actual vehicle acceleration due to the deviation of the direction of the acceleration sensor from the vehicle body progress and the response delay of the acceleration sensor, and the estimated vehicle speed is lower than the actual vehicle speed. Will also be lower. Therefore, the difference between the drive wheel rotation speed and the estimated vehicle speed becomes large,
It is determined that a large slip has occurred, and the amount by which the drive torque of the engine is reduced becomes unnecessarily large, resulting in poor acceleration. Therefore, in the present invention, when turning, it is difficult to enter the mode for estimating and calculating the vehicle speed based on the acceleration sensor signal, and when entering the mode for estimating and calculating the vehicle speed, the vehicle speed estimated and calculated based on the acceleration sensor signal is I tried to make a correction that is higher than when.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the intake and exhaust of an embodiment in which a vehicle output control device according to the present invention is applied to a four-wheel drive type vehicle in which a hydraulic automatic transmission having four forward gears and one reverse gear is incorporated. Represents the concept of the system. FIG. 2 shows the concept of the drive system.
As shown in both figures, the engine 11 has a torque converter 12
The automatic transmission 13 is connected via. The automatic transmission 13 is provided from an electronic control unit (hereinafter referred to as an ECU) 14 that controls the operating state of the engine 11 in accordance with the selected position of a select lever (not shown) by the driver and the operating state of the vehicle. Based on the command, a predetermined shift speed is automatically selected via a hydraulic control device (not shown).

The specific structure and operation of the automatic transmission 13 are already known, for example, in Japanese Patent Laid-Open No. 58-54270 and Japanese Patent Laid-Open No. 61-31749. Includes a plurality of shift control solenoid valves (not shown) for engaging and releasing a plurality of friction engagement elements that form a part of the automatic transmission 13. By controlling the ON / OFF operation of the energization of these shift control solenoid valves by the ECU 14, the shift operation to any shift stage of the forward 4 stages and the reverse 1 stage is smoothly achieved.

An expiratory tube 17 having an air cleaner 15 attached to its tip end communicates with a combustion chamber 16 of the engine 11. A throttle body 20 is provided in the middle of the intake pipe 17. The throttle body 20 incorporates a throttle valve 19 that adjusts the amount of intake air supplied into the combustion chamber 16 by changing the opening of the intake passage 18 formed by the intake pipe 17.

As shown in FIGS. 1 and 3 (representing an enlarged cross-sectional structure of a cylindrical throttle body 20), the throttle body 20 has both ends of a throttle shaft 21 integrally fixed with a throttle valve 19. It is rotatably supported. This throttle shaft 21 protruding into the intake passage 18
An accelerator lever 22 and a throttle lever 23 are coaxially fitted to one end of the.

The throttle shaft 21 and the accelerator lever 2
The bush 25 and the spacer 26 are provided between the second tubular portion 24 and the second tubular portion 24.
Is interposed, whereby the accelerator lever 22 is rotatable with respect to the throttle shaft 21. Further, a washer 27 and a nut 28 attached to one end side of the throttle shaft 21 are used to connect the throttle shaft 21 to the accelerator lever 22.
It prevents from slipping out. An accelerator pedal 30 operated by a driver is connected to a cable receiver 29 integrated with the accelerator lever 22 via a cable 31, and the accelerator lever 22 is connected to the throttle shaft in accordance with the depression amount of the accelerator pedal 30. It is adapted to rotate with respect to 21.

On the other hand, the throttle lever 23 is fixed integrally with the throttle shaft 21. Therefore, by operating the throttle lever 23, the throttle valve 1
9 rotates together with the throttle shaft 21. Further, a collar 32 is coaxially and integrally fitted to the tubular portion 24 of the accelerator lever 22, and a tip portion of the throttle lever 23 is engaged with a claw portion 33 formed on a part of the collar 32. A stopper 34 that can be used is formed. The claw portion 33 and the stopper 34 are locked to each other when the throttle lever 23 is rotated in the opening direction of the throttle valve 19 or the accelerator lever 22 is rotated in the closing direction of the throttle valve 19. It is set in a proper positional relationship.

Between the throttle body 20 and the throttle lever 23, the stopper 34 of the throttle lever 23 is pressed against the claw portion 33 of the collar 32 integral with the accelerator lever 22 to urge the throttle valve 19 in the opening direction. A torsion coil spring 35 is mounted coaxially with the throttle shaft 21 via a pair of cylindrical spring receivers 36 and 37 fitted to the throttle shaft 21.
Also, the stopper pin 3 protruding from the throttle body 20
8 and the accelerator lever 22 as well, the claw portion 33 of the collar 32 is pressed against the stopper 34 of the throttle lever 23 to urge the throttle valve 19 in the closing direction to give a detent feeling to the accelerator pedal 30. A torsion coil spring 39 for doing so is attached to the cylinder portion 24 of the accelerator lever 22 via the collar 32 so as to be coaxial with the throttle shaft 21.

At the tip of the throttle lever 23,
The distal end portion of a control rod 42 whose base end is fixed to the diaphragm 41 of the actuator 40 is connected. In the pressure chamber 43 formed in the actuator 40, the torsion coil spring 35 and the stopper 34 of the throttle lever 23 are pressed against the claw portion 33 of the collar 32 to urge the throttle valve 19 in the opening direction. 44 is incorporated. Then, the spring force of the torsion coil spring 39 is set to be larger than the sum of the spring forces of these two springs 35 and 44, whereby the accelerator pedal 3
The throttle valve 19 is not opened unless the user depresses 0.

A surge tank 45 which is connected to the downstream side of the throttle body 20 and forms a part of the intake passage 18.
A vacuum tank 47 communicates with the via a connection pipe 46. This vacuum tank 47 and connection piping 46
Between the vacuum tank 47 and the surge tank 4
A non-return valve 48 that allows only the movement of air to 5 is provided. As a result, the pressure in the vacuum tank 47 is set to a negative pressure substantially equal to the minimum pressure in the surge tank 45.

The inside of the vacuum tank 47 and the pressure chamber 43 of the actuator 40 are in communication with each other through a pipe 49, and in the middle of the pipe 49, there is a closed type first torque control for non-energization. A solenoid valve 50 is provided. That is, the torque control solenoid valve 50 has a pipe 49.
A spring 53 that urges the plunger 51 toward the valve seat 52 so as to close the valve is incorporated.

In addition, a pipe 49 between the first torque control solenoid valve 50 and the actuator 40 is connected to a pipe 54 communicating with the intake passage 18 upstream of the throttle valve 19.
Are connected. A second torque control solenoid valve 55, which is open when not energized, is provided in the middle of the pipe 54. That is, the torque control solenoid valve 55 has a spring 5 for biasing the plunger 56 so as to open the pipe 55.
7 is incorporated.

The two torque control solenoid valves 50, 55
The ECU 14 is connected to the
4 based on the command from the torque control solenoid valves 50, 55
Duty control is performed to turn on and off the energization of the. In the present embodiment, the torque reducing means of the present invention is constituted by these as a whole.

For example, when the duty ratio of the torque control solenoid valves 50, 55 is 0%, the pressure chamber 43 of the actuator 40 has the intake passage 18 upstream of the throttle valve 19.
The atmospheric pressure becomes almost equal to the internal pressure, and the throttle valve 19
The opening degree corresponds to the depression amount of the accelerator pedal 30 on a one-to-one basis. On the contrary, when the duty ratio of the torque control solenoid valves 50, 55 is 100%, the pressure chamber 43 of the actuator 40 becomes a negative pressure almost equal to the pressure in the vacuum tank 47, and the control rod 42 is slanted to the left in FIG. As a result of being pulled upward, the throttle valve 19 is closed regardless of the depression amount of the accelerator pedal 30, and the driving torque of the engine 11 is forcibly reduced. In this way
By adjusting the duty ratios of the torque control solenoid valves 50 and 55, the opening degree of the throttle valve 19 can be changed regardless of the depression amount of the accelerator pedal 30, and the drive torque of the engine 11 can be arbitrarily adjusted.

Further, in this embodiment, the opening degree of the throttle valve 19 is controlled simultaneously by the accelerator pedal 30 and the actuator 40. However, two throttle valves are arranged in series in the intake passage 18 and one throttle valve is arranged. Connect the valve only to the accelerator pedal 30 and the other throttle valve only to the actuator 40 to control these two throttle valves independently, or to electrically drive one throttle valve by a motor, etc. Is also possible.

The output shaft 58 of the automatic transmission 13 has a planetary gear type center differential (hereinafter referred to as a center differential) which distributes driving torques for the front wheels 59R, 59L and the rear wheels 60R, 60L to a required ratio. 6)
1 are connected via an intermediate gear 62.

This center differential 61 is provided with a sun gear 63.
And a plurality of planetary gears 64 arranged around the sun gear 63 and meshing with the sun gear 63, and an internal gear 65 arranged coaxially with the sun gear 63 so as to surround the planetary gears 64, A planet carrier 66 that rotatably supports the planet gears 64 meshes with the intermediate gear 62. A front differential (hereinafter, referred to as a front differential) 69 is connected to the sun gear 63 via a reduction gear 68 integral with a front wheel output shaft 67,
The internal gear 65 includes a rear wheel output shaft 70 and a bevel gear group 7.
The propeller shaft 72 is connected via 1.

That is, one output of the center differential 61 is transmitted through the reduction gear 68 and the front differential 69 to the front axle 7
3R, 73L is transmitted to the left and right front wheels 59R, 59L, the other output is bevel gear group 71, propeller shaft 72 and bevel gear group 7
4, Rear axle 76R via rear differential 75,
It is transmitted from 76L to the left and right rear wheels 60R, 60L.

The front diff 69 has front and rear wheels 59R, 59L, 60R, 60L (hereinafter referred to as drive wheels) by limiting or restraining the differential between the front wheel side output section and the rear wheel side output section. (Hereinafter collectively referred to as)), a hydraulic multi-plate clutch 77 that can change the distribution of the drive torque from the engine 11 is additionally provided. This hydraulic multi-plate clutch 77 is provided with a sun gear 63.
And the planet carrier 66, and the engagement force is changed by the hydraulic pressure supplied to the hydraulic multi-plate clutch 77 (hereinafter, referred to as clutch engagement pressure), and the sun gear 63 and the planet carrier. The constraint state of the differential with 66 can be changed.

Therefore, by controlling the clutch engagement pressure with respect to the hydraulic multi-plate clutch 77, the hydraulic multi-plate clutch 77 is held in an arbitrary state from the completely released state to the integrally engaged state. It becomes possible. Therefore, the center differential 61 has front wheels 59R, 59L side and rear wheels 6
The distribution ratio of the drive torque transmitted to the 0R, 60L side can be controlled from, for example, about 32:68 to a ratio (for example, 60:40) according to the ground load of these drive wheels.

The distribution ratio of the driving torque between the front wheels 59R, 59L and the rear wheels 60R, 60L when the hydraulic multi-plate clutch 77 is completely released is determined by the number of teeth of the sun gear 63, the planetary gear 64, and the internal gear 65. , It can be set arbitrarily according to the tooth number ratio between the bevel gear group 71 and the reduction gear 68, but in this embodiment, the distribution ratio of the drive torque between the front wheels 59R, 59L and the rear wheels 60R, 60L is about 32: It is set to be 68. When the hydraulic multi-plate clutch 77 is completely engaged and the differential limit becomes substantially zero, the front wheels 59R,
The distribution ratio of the driving torque between the 59L and the rear wheels 60R, 60L is
A ratio according to the ground load of these drive wheels (for example, 60: 4)
0).

In this embodiment, the hydraulic multi-plate clutch 77 is used.
Although it is interposed between the sun gear 63 and the planet carrier 66, it may be interposed between the sun gear 63 and the internal gear 65.

FIG. 4 shows the concept of a pressure oil control circuit for the hydraulic multi-plate clutch 77. As shown in FIG. 4, a hydraulic multi-plate clutch 77 is connected to an oil pump 79 that sucks up oil in an oil sump 78 of the automatic transmission 13 via an oil passage 101 having a pressure control valve 80 in the middle. ing. A pressure switch 81 for detecting the oil pressure in the oil passage 101 is provided in the middle of the oil passage 101 between the hydraulic multi-plate clutch 77 and the pressure control valve 80, and the detection signal is output to the ECU 14. It is like this.

Further, in the middle of the branch oil passage 102 communicating with the oil passage 101 between the oil pump 79 and the pressure control valve 80 and the oil sump 78 of the automatic transmission 13, a set pressure (hereinafter It is called a line pressure), for example, about 9 kg / cm ² , and a relief valve 82 is provided to allow the oil in the oil passage 101 to escape to the oil sump 78 of the automatic transmission 13.

The pressure control valve 80 has a first position where the hydraulic multi-plate clutch 77 and the oil pump 79 communicate with each other, and a second position where the hydraulic multi-plate clutch 77 communicates with the oil sump 78 of the automatic transmission 13. And the positions of these are changed to ECU1.
The duty ratio is controlled by the output signal from No. 4.

FIG. 5 shows a specific hydraulic control circuit of the pressure control valve 80. As shown in FIG. 5, the pressure control valve 80 opens and closes the land 801 that opens and closes the oil passage 101 that connects the oil pump 79 and the hydraulic multi-plate clutch 77, and opens and closes the drain oil passage 103 that communicates with the oil sump 78. And a spool 8 in which these two lands 801 and 802 are formed at the center and one end side.
03 and a return spring 804 that biases the spool 803 to the right side in the drawing.

An oil passage 104 branched from the oil passage 101 between the oil pump 79 and the pressure control valve 80 and an oil passage 105 facing the end surface of the land 802 on one end side of the spool 803 of the pressure control valve 80. A reducing valve 83 is interposed between them. The reducing valve 83 includes a spool 833 formed with a land 831 that can open and close the oil passage 104 and a land 832 that can open and close the oil discharge passage 106, and the spool 833 in the drawing.
It has a return spring 834 which urges it to the left side.

That is, when the hydraulic pressure in the oil passage 105 becomes equal to or lower than the set pressure (hereinafter, referred to as reducing pressure) corresponding to the spring force of the return spring 834, the spring force of the return spring 834 causes the spool 833 to move. As a result of being pressed to the left side in the figure, the oil passages 104 and 105 communicate with each other, and the line pressure from the oil pump 79 is supplied from the oil passages 101 and 104 to the oil passage 105 via the reducing valve 83. On the contrary, when the oil pressure in the oil passage 105 becomes equal to or higher than the reducing pressure, the spool 833 is pressed to the right side in the figure against the spring force of the return spring 834.
And the oil discharge passage 106 communicate with each other, the pressure oil in the oil passage 105 is discharged from the oil discharge passage 106 via the reducing valve 83, and thus the oil passage 105 is always maintained at a constant reducing pressure. It has become so.

The pressure control valve 80 is branched from the oil passage 105.
Oil passage 10 facing the end surface of land 801 in the center of spool 803
An orifice 108 is provided in the middle of 7. In the middle of a control oil passage 109 that branches from the oil passage 107 between the orifice 108 and the pressure control valve 80, a clutch control solenoid valve for switching the communication state between the control oil passage 109 and the drain oil passage 110. 84 is provided.

The clutch controlling solenoid valve 84 is a non-energizing closed type valve in which the energization state of the solenoid 841 is duty controlled by the ECU 14 based on information from various sensors described later. The magnetic force generated by the solenoid 841 and the spring force of the return spring 843 cause lateral displacement in the figure. That is, when the solenoid 841 is energized, the valve body 842 moves to the right side in the figure by the electromagnetic force against the spring force of the return spring 843, and the control oil passage 109 and the drain oil passage 110 communicate with each other. Meanwhile, when the solenoid 841 is not energized, the spring force of the return spring 843 moves the valve body 842 to the left side in the figure,
The control oil passage 109 is shut off from the oil discharge passage 110.

As a result, when the control oil passage 109 and the drain oil passage 110 communicate with each other and the hydraulic pressure in the oil passage 107 (hereinafter, referred to as duty pressure) decreases, the return spring of the pressure control valve 80 is reduced.
Land 802 on one end side of spool 803 against the spring force of 804
As a result of the spool 803 of the pressure control valve 80 moving to the left side in the drawing due to the reducing pressure acting on the end surface of the line, the line pressure supplied from the oil pump 79 through the oil passage 101 is
The pressure control valve 80 supplies the clutch engagement pressure to the hydraulic multi-plate clutch 77, and the hydraulic multi-plate clutch 77 enters the engaged state. On the contrary, when the control oil passage 109 is shut off from the drain oil passage 110 and the duty pressure rises and becomes almost equal to the reducing pressure, the spring force of the return spring 804 of the pressure control valve 80 causes the spool of the pressure control valve 80. As a result of 803 moving to the right side in the figure, the hydraulic multi-plate clutch 77 and the oil discharge path 103 communicate with each other, and the hydraulic multi-plate clutch 77 is opened.

The above-mentioned clutch engagement pressure changes depending on the duty ratio of the clutch control solenoid valve 84. The clutch engagement pressure and the clutch control solenoid valve 84 are changed.
The duty ratio of 1 is proportional to that shown in FIG. 6, for example. Specifically, the clutch control solenoid valve 84
The smaller the duty ratio is (i.e., the smaller the energization amount is), the lower the clutch engagement pressure is. On the contrary, the larger the duty ratio to the clutch control solenoid valve 84 is (the larger the energization amount is, the higher the clutch engagement pressure is. Has become.

Incidentally, the reverse setting, that is, the characteristic in FIG. 6 is lowered to the right, and the duty ratio to the clutch control solenoid valve 84 is small (that is, the energization amount is small).
It is also possible to set the clutch engagement pressure to be higher as the clutch engagement pressure becomes higher, and conversely, the clutch engagement pressure to become lower as the duty ratio to the clutch control solenoid valve 84 increases (that is, the energization amount increases).

As described above, in this embodiment, the clutch engagement pressure for the hydraulic multi-plate clutch 77 is appropriately set based on the detection signals from the various sensors for detecting the operating state of the vehicle, and the drive torque is distributed to the drive wheels. Although the ratio is appropriately switched, the control of the hydraulic multi-plate clutch 77 is essentially unrelated to the present invention, so
The description is omitted.

On the other hand, the ECU 14 has a throttle opening sensor 85 attached to the throttle body 20 for detecting the opening of the throttle lever 23 (hereinafter referred to as throttle opening), and this throttle opening sensor. An accelerator opening sensor 86 mounted on the throttle body 20 in the same manner as 85 to detect the opening (hereinafter referred to as accelerator opening) θ _A of the accelerator lever 22.
When a crank angle sensor 87 for detecting the mounted by the engine rotational speed N _E of the engine 11, a steering wheel 88
The steering angle sensor 90 for detecting the turning angle δ _H of the steering shaft 89 to which the vehicle is mounted is based on the straight traveling state of the vehicle, and the longitudinal acceleration sensor 91 as the longitudinal acceleration detecting means of the present invention for detecting the longitudinal acceleration G _{X of the} vehicle. And a pair of front and rear lateral acceleration sensors 92a, 92b mounted on the front and rear of the vehicle for detecting the lateral acceleration G _{Y of the} vehicle and a pair of left and right front wheel rotation sensors 9 for detecting the rotational speeds of the front wheels 59R, 59L, respectively.
3R, 93L is connected to a pair of left and right rear wheel rotation sensors 94R, 94L for detecting the rotational speeds of the rear wheels 60R, 60L, respectively, and is attached to the throttle body 20 to detect the fully closed state of the throttle valve 19. Idle switch 95
And an ignition key switch 96 are connected.

The throttle opening sensor 8
5, accelerator opening sensor 86, crank angle sensor 87,
The output signals from the steering angle sensor 90, the longitudinal acceleration sensor 91, the lateral acceleration sensors 92a and 92b, the front wheel rotation sensors 93R and 93L, the rear wheel rotation sensors 94R and 94L, the idle switch 95, and the ignition key switch 96 are respectively EC.
It will be sent to U14.

By the way, in a four-wheel drive type vehicle, the drive torque from the engine 11 is transmitted to all four drive wheels, so that the drive force from the engine 11 such as the two-wheel drive type vehicle is not transmitted. Hereinafter, this will be referred to as a driven wheel), and the vehicle speed V cannot be detected from the rotational speed of the driven wheel. Therefore, details will be described later,
In this embodiment, the longitudinal acceleration G _X detected by the longitudinal acceleration sensor 91 and the front and rear wheel rotation sensors 93R, 93L, 94R,
The vehicle speed V is obtained by calculating based on the 94L signal. The method of obtaining the vehicle speed V is the point of the present invention.

Further, in this embodiment, when the slip amount s in the front-rear direction of the drive wheels, which will be described later, becomes larger than a preset amount, the drive torque of the engine 11 is reduced to ensure maneuverability and energy loss. control for preventing (hereinafter referred to as slip control) were computed by ECU14 target driving torque T _O of the engine 11 when performing a are allowed to be reduced if necessary drive torque of the engine 11 .

FIG. 7 shows a rough flow of control according to this embodiment. As shown in FIG. 7, specifically, the control program of the present embodiment is started by turning on the ignition key switch 96, and in step M1, first, the initial value of the steering shaft turning position is read and slip control to be described later is being performed. Initialization such as resetting the flag F or starting counting of the main timer every 15 milliseconds which is a sampling period of this slip control is performed.

Then, in step M2, the ECU 14 calculates longitudinal acceleration G _X , lateral acceleration G _Y , driving wheel speed V _D, etc. based on the detection signals from various sensors, and subsequently, the steering shaft 89 is neutralized. The position is learned and corrected in the step of M3.
Since the neutral position of the steering shaft 89 is not stored in a memory or the like (not shown) in the ECU 14, the initial value is read every time the ignition key switch 96 is turned on, and when the vehicle satisfies the straight running condition. Only the learning correction is performed, and the initial value is learned and corrected until the ignition key switch 96 is turned off.

Next, the ECU 14 executes the steering angle sensor 90, the longitudinal acceleration sensor 91, the lateral acceleration sensors 92a and 92b, the front and rear wheel rotation sensors 93R and 93L, in the step M4.
94R, calculates the target driving torque T _O for performing slip control for regulating the driving torque of the engine 11 based on the detection signal from the 94L.

If the driver operates a manual switch (not shown) and desires slip control, the EC
In U14, the drive torque of the engine 11 is the target drive torque T
_The pair of torque control solenoid valves 50,
The duty ratio of 55 is controlled so that the vehicle travels reasonably and safely.

If the driver does not desire slip control by operating a manual switch (not shown), the EC
As a result of U14 setting the duty ratio of the pair of torque control solenoid valves 50, 55 to the 0% side, the vehicle is in a normal operating state corresponding to the amount of depression of the accelerator pedal 30 by the driver.

In this way, the drive torque of the engine 11 is changed to M5.
In the step, control is performed until the countdown of the main timer for each sampling period is completed, and thereafter, from M2
Ignition key switch 9
This is repeated until 6 is turned off.

By the way, in the present embodiment, at the time of slip control in the step of M4, a pair of lateral acceleration sensors 92a, 92a
Based on 2b, the actual lateral acceleration G _Y is detected by the lateral acceleration calculation unit 203, while this lateral acceleration G _Y during turning is estimated as the lateral acceleration G _YE based on the turning angle δ _H of the steering shaft 89 and the vehicle speed V. Actual lateral acceleration G _Y predicted and generated in the vehicle
In contrast, the estimated lateral acceleration G _YE that can be predicted in advance is used preferentially to correct the reference drive torque T _B of the engine 11 in a state where there is almost no possibility of a control delay.

However, when servicing the vehicle, the front wheels 59R, 59L
If the neutral position of the steering shaft 89 changes due to secular change such as wear adjustment of the steering gear (not shown) or the like, the turning position of the steering shaft 89 and the front wheels 59R, 59L, which are the steered wheels, will actually be changed. There is a deviation from the steering angle δ of. As a result, the estimated lateral acceleration G _YE of the vehicle cannot be accurately calculated. In this case, therefore, the pair of lateral acceleration sensors 92a and 92b is used to drive the reference drive of the engine 11 using the actual lateral acceleration G _Y. Correct the torque T _B.

For this reason, it is necessary to learn and correct the neutral position of the steering shaft 89 in the step of M3. Regarding the method of learning and correcting the neutral position of the steering shaft 89, Japanese Patent Laid-Open No. 3-189273. Since it is already known in the gazette and the like, its detailed description is omitted.

The ECU 14 controls the front wheels 59 based on the turning angle δ _H of the steering shaft 89 detected by the steering angle sensor 90.
The steering angle δ of R and 59L is calculated by the following equation (1), and the estimated lateral acceleration G _YE of the vehicle at this time is obtained by the following equation (2). That is, the calculation processing by the equations (1) and (2) in the ECU 14 corresponds to the lateral acceleration detecting means. δ = δ _H / ρ _H (1) G _YE = δ / [ω ・ {A + (1 / V ² )}] (2) where ρ _H is the steering gear speed ratio and ω is the vehicle , A is the vehicle stability factor.

As is well known, the stability factor A is a value determined by the structure of the vehicle suspension system, the tire characteristics, the road surface condition, and the like. Specifically, the actual lateral acceleration G _Y generated in the vehicle at the time of steady circle turning, and the steering angle ratio δ _H / δ _HO of the steering shaft 89 at this time (the lateral acceleration G based on the neutral position of the steering shaft 89). A graph showing the relationship between the turning angle δ _HO of the steering shaft 89 in the extremely low speed traveling state where _Y is close to 0 and the ratio of the turning angle δ _H of the steering shaft 89 during acceleration), for example, as shown in FIG. It is expressed as the slope of the tangent line at. That is, in a region where the lateral acceleration G _Y of the vehicle running on the dry road is small and the vehicle speed V is not too high, the stability factor A is a substantially constant value (A = 0.002).
However, when the lateral acceleration G _Y exceeds, for example, 0.6 g, the stability factor A increases sharply, and the vehicle exhibits an extremely strong understeering tendency.

The friction coefficient between the tire mounted on the driving wheel and the road surface can be regarded as equivalent to the longitudinal acceleration G _X which is the rate of change of the vehicle speed V. Therefore, in the present embodiment, the longitudinal acceleration G _X is continuously obtained by the detection signal from the longitudinal acceleration sensor 91, and the reference drive torque T _B of the engine 11 corresponding to the maximum value of the longitudinal acceleration G _X is set as the slip amount s. corrected based on - (a driving wheel speed V _D target driving wheel speed V _FO), calculates the target driving torque T _O.

In this case, the front and rear wheel rotation sensors 93R, 93L,
The drive wheel speed V _D calculated based on the detection signals from 94R, 94L is the front / rear wheel rotation sensor 93R, 93L, 94R, 94L.
The average of the first and second magnitudes of the rotational speed data of the drive wheels detected by is used as the drive wheel speed V _D.

[0064] Figure 9 shows a calculation block for calculating the target driving torque T _O of the engine 11 in FIG. 10. As shown in both figures, the ECU 14 detects the current longitudinal acceleration G _{X (n)} of the vehicle based on the detection signal from the longitudinal acceleration sensor 91. Based on the longitudinal acceleration G _{X (n)} , the turning angle δ _H of the steering shaft 89 detected by the steering angle sensor 90, and the signals of the front and rear wheel rotation sensors 93R, 93L, 94R, 94L, the vehicle speed calculation unit 3
The vehicle speed V is calculated from 00 (details will be described with reference to FIG. 11).

Here, the configuration and operation of the vehicle speed calculation unit 300 will be described.
Description will be made with reference to FIG. This vehicle speed calculation unit 300 is introduced to apply the "vehicle output control device" to a 4WD vehicle, and this portion is the point of the present invention.

As shown in FIG. 11, the longitudinal acceleration sensor 9
The longitudinal acceleration G _X output from 1 is the low-pass filter 3
The noise component is removed at 01 and the filter longitudinal acceleration G _Xf
Becomes The peak hold unit 302 outputs a peak-hold longitudinal acceleration G _XfP obtained by peak-holding the filter longitudinal acceleration G _Xf (slowly decreasing with a certain time constant after peak). Even if a signal component smaller than the actual vehicle body acceleration is output due to poor mounting accuracy of the longitudinal acceleration sensor 91, poor accuracy of the sensor itself, response delay, road gradient, etc. due to peak hold The bad signal component can be solved.

The switch section 303 controls the vehicle speed V (this value will be described later).
As shown in FIG. 11, the vehicle speed calculation unit 300
Is more than 20 [km / h].
Filter longitudinal acceleration G_XfIs selected and output, and the vehicle speed V is 2
Peak hold longitudinal acceleration G if less than 0 [km / h]
_XfPTo output. Here, select with the switch unit 303.
Select the output signal and switch forward / backward acceleration G_XSWTosu
It When the vehicle speed V is 20 [km / h] or more, the peak
Front / back acceleration G that is not shielded_XfUsing
Therefore, from a road surface with a high friction coefficient (high μ road surface) to a low road such as a snow road.
Even if you jump into a road surface with a friction coefficient (low μ road surface) and accelerate,
I immediately responded to the situation when I entered the snowy road, etc.
It is possible to obtain longitudinal acceleration values and drive on a road surface with a high friction coefficient.
No longer affected by high longitudinal acceleration
Therefore, correct slip control can be performed. Conversely, the vehicle speed V
When peak is 20 [km / h] or more
Speed G _XfPIf is used, it means that from high μ road surface to low μ road surface
If you jump into the surface and accelerate, the low μ₀High μ even on the road
Since the data on the road surface is held, high μ₀
Assuming that the vehicle is accelerating on par with the road surface, the estimated vehicle speed calculator 30 in the next stage
The vehicle speed is calculated at 4 and the estimated vehicle speed V_BFrom the actual vehicle speed
Large deviation, unable to perform correct slip control
It will be. Therefore, once the vehicle has started smoothly,
If V is 20 [km / h] or more, filter longitudinal acceleration G
_XfWhen the vehicle speed V is less than 20 [km / h],
Peak hold longitudinal acceleration G if there is_XfPSelect.

The estimated vehicle speed calculation unit 304 operates the switch longitudinal acceleration G _XSW and the steering angle sensor 9 output from the switch unit 303.
When the turning angle δ _H of the steering shaft output from 0 is input,
The estimated vehicle speed V _B is calculated using the following equation (A). V _B = V _B0 + ∫β · G _XSW dt (A) However, V _B0 is the value of the reference wheel speed V ₃ at the time when the vehicle speed selection output unit 305 of the next stage selects the estimated vehicle speed V _B. is there. The variable beta, small characteristic values shown in FIG. 12 when the turning angle [delta] _H is less than 180 ° taking a (change over time), when the turning angle [delta] _H is greater than or equal 180 ° large characteristic values shown in FIG. 13 Take a (constant value 1.5).

After all, when the turning angle δ _H is 180 ° or more, the variable β is large and the estimated vehicle speed V _B is large (see the equation (A), FIG. 11, FIG. 12, and FIG. 13). During turning, the longitudinal acceleration G _X is deviated due to the difference between the direction of the longitudinal acceleration sensor 91 and the traveling direction of the vehicle body and the response delay of the longitudinal acceleration sensor 91.
Since (G _XSW ) tends to be lower than the actual vehicle speed, this problem is compensated by changing the value of β according to the turning angle. Therefore, it is possible to prevent the estimated vehicle speed V _{B from} becoming unnecessarily small during turning and determine that slip has occurred, and reduce the drive torque of the engine to prevent a situation in which acceleration failure occurs.

On the other hand, when the rotation speed of each wheel is input from the front and rear wheel rotation sensors 93R, 93L, 94R, 94L, the reference wheel speed selection unit 306 selects the third wheel rotation speed from the faster one. This is output as the reference wheel speed V ₃ . The reference wheel speed V ₃ is sent to the vehicle speed selection output unit 305 and the differentiation unit 307. Differentiating section 307 calculates and outputs a reference wheel acceleration G ₃ by differentiating the reference wheel speed V _3. The filter 308 filters the reference wheel acceleration G ₃ to remove noise components and outputs a filter reference wheel acceleration G _3f .

The comparison unit 309 performs a comparison operation represented by the following expression (B). G _3f > G _Xf + α (B) In the above equation, the variable α [m / S ² ] is changed according to the turning angle δ _H deg of the steering shaft, as shown in FIG. That is, δ _H is 180 °
If it is less than α, α = 2.45, and if δ _H is 180 ° or more, α = 4.9. In other words, it is difficult to satisfy equation (B) when turning. Note that the expression (B) is established means that the reference wheel slips.

The comparison unit 310 performs a comparison operation represented by the following expression (C). V _B ≧ V ₃ (C) If the formula (C) is satisfied, it means that the slip of the reference wheel has disappeared.

When the equation (B) is established, the vehicle speed selection comparing section 305 switches from the contact point 305a to the contact point 305b, and changes the output vehicle speed V from the reference wheel speed V ₃ to the estimated wheel speed V _B.
In this case, since the value of α is set as shown in FIG. 14, expression (B) is difficult to be established during turning, and it is difficult to change the mode in which the vehicle speed V is V ₃ to the mode in which it is V _B. There is. That is, during turning, the reference wheel speed V ₃ is likely to be disturbed, and the filter reference wheel acceleration G _3f is also easily disturbed, and due to this disturbance (a noise-like movement that is not the original movement), G is larger than G _{Xf.
Although 3f} tends to be large, in order to suppress such a defective operation determination, the value of α at the time of turning in the expression (B) is increased to make it difficult to satisfy the expression (B), and the V ₃ mode is changed to the V It is difficult to switch to _B mode.

Further, the vehicle speed selection / comparison unit 305 selects the estimated vehicle speed V _B as the vehicle speed V, and if the formula (C) is satisfied, the contact 30
It switches from 5b to the contact 305a, converts the vehicle speed V which is output from the estimated vehicle speed V _B to the reference wheel speed V _3.

After all, the operation of the vehicle speed calculation unit 300 shown in FIG. 11 is summarized as follows. (1) As the vehicle speed V, either the estimated vehicle speed V _B calculated by the equation (A) based on the longitudinal acceleration G _X or the third reference wheel speed V ₃ of the four wheel speeds is used. (2) When the reference wheel slips, that is, when the equation (B) is satisfied, the vehicle speed V is calculated from the reference wheel speed V ₃ to the estimated vehicle speed V _B.
Switch to. In this case, the value of α in the expression (B) is adjusted to make it difficult to switch when turning. Further, the value of β in the expression (A) is adjusted to prevent the estimated vehicle speed during turning from becoming too low. (3) when there is no reference wheel slip, when that is the formula (C) is satisfied, return the vehicle speed V from the estimated vehicle speed V _B to the reference wheel speed V _3.

Thus, also in the 4WD vehicle, the vehicle speed V can be satisfactorily obtained by using the vehicle speed calculation unit 300 shown in FIG. This is the end of the description of the vehicle speed calculation unit 300, which is the point of the present invention. Next is Fig. 9 and Fig. 10.
Returning to, the description of the calculation block for calculating the target drive torque T ₀ will be continued.

The turning angle δ _H of the steering shaft 89 detected by the steering angle sensor 90 and the vehicle speed V calculated by the vehicle speed calculating section 300 are one of the lateral acceleration calculating means which is one of the lateral acceleration calculating means.
202 is output to the estimated lateral acceleration calculation unit 202
The estimated lateral acceleration G _YE is calculated by the equations (1) and (2).

If the neutral position of the steering shaft 89 is not learned and corrected, or if an abnormality occurs in the steering angle sensor 90, it is possible that the estimated lateral acceleration G _YE becomes a completely incorrect value. Therefore, when the neutral position of the steering shaft 89 is not learned and corrected, or when an abnormality occurs in the steering angle sensor 90 or the like, an actual vehicle generated based on the detection signals from the lateral acceleration sensors 92a and 92b. The lateral acceleration G _Y is detected and used in place of the estimated lateral acceleration G _YE .

Specifically, the lateral acceleration sensors 92a, 92b
The lateral acceleration calculation unit 203 calculates the average value of the detection signals from the, and the corrected lateral acceleration G _{YF obtained} by _performing noise removal processing on this by the filter unit 204 is used as the actual lateral acceleration G _Y.
That is, the lateral acceleration computing unit 203 and the filter unit 204 are the other lateral acceleration computing means. The filter unit 204 digitally calculates the corrected lateral acceleration G _{YF (n)} of this time from the lateral acceleration G _{Y (n)} calculated this time and the corrected lateral acceleration G _{YF (n-1)} calculated last time. Low pass processing is performed. G _{YF (n)} = Σ [(20/256) ・ {G _{Y (n)} −
G _{YF (n-1)} }]

FIG. 15 shows a procedure for selecting the estimated lateral acceleration G _YE and the corrected lateral acceleration G _YF . As shown in FIG. 15, the ECU 14 first executes the filter unit 20 in step Y1.
The corrected lateral acceleration G _YF from 4 is adopted, and it is determined in step Y2 whether or not the slip control flag F _S is set.

If it is determined in step Y2 that the slip control flag F _S is set, the corrected lateral acceleration G _YF is used as it is. This is because when the corrected lateral acceleration G _YF is changed to the estimated lateral acceleration G _YE during the slip control, the maximum longitudinal acceleration G _XM and the slip correction amount V _{KC, which} will be described later, may change significantly and the vehicle behavior may be disturbed. Is.

If it is determined in the step Y2 that the slip control flag F _S is not set, Y3
At, it is determined whether the learning of the steering angle neutral position is completed. Here, even when it is determined that the learning of the steering angle neutral position has not been completed, the corrected lateral acceleration G _YF in the step Y1 is directly adopted, and the process returns to the step Y2. Also, this Y3
If it is determined that the learning of the steering angle neutral position has been completed in the step of, the estimated lateral acceleration G _{YE is} calculated in the step of Y4.
Is adopted, and the process returns to the step Y2.

As described above, in this embodiment, the two lateral acceleration sensors 92a and 92b are provided and the average value of these two detection data is adopted as the lateral acceleration G _Y. However, one lateral acceleration sensor of the vehicle is used. It is also possible to provide near the center of gravity and obtain the corrected lateral acceleration G _YF based on this detected value.

According to the magnitude of the estimated lateral acceleration G _YE calculated by the estimated lateral acceleration calculation unit 202, the longitudinal acceleration G _{X (n) is changed} to the maximum longitudinal acceleration G by the upper limit clip unit 205 which is the longitudinal acceleration limiter. Clip to _{XM (n)} . The maximum longitudinal acceleration G _{XM (n)} represents the relationship between the estimated lateral acceleration G _YE stored in advance in the ECU 14 and the maximum longitudinal acceleration G _{XM (n)} .
6, the longitudinal acceleration sensor 9 is read from the map as shown in FIG.
If the longitudinal acceleration G _{X (n)} detected from 1 is greater than or _equal to this maximum longitudinal acceleration G _{XM (n)} , this is set to the maximum longitudinal acceleration G _X
Clip to _{XM (n)} . Further, the filter unit 206 performs a later-described filter process for noise removal to calculate a corrected longitudinal acceleration G _XF .

As shown in FIG. 17 showing the relationship between the tire slip ratio S and the friction coefficient between the tire and the road surface, the processing in the filter unit 206 is a longitudinal acceleration G _{X (n)} of the vehicle.
Can be regarded as equivalent to the friction coefficient between the tire mounted on the driving wheel and the road surface, and therefore the maximum value of the longitudinal acceleration G _{X (n)} of the vehicle changes and the slip ratio S of the tire is Even if the target slip ratio S 0 corresponding to the maximum value of the friction coefficient between the tire and the road is about to deviate from the target slip ratio S _O , the slip ratio S of the tire is changed to the target slip ratio S corresponding to the maximum value of the friction coefficient between the tire and the road surface. This is to correct the longitudinal acceleration G _{X (n)} clipped to the maximum longitudinal acceleration G _{XM (n)} so as to maintain a value smaller than _{O at} or near _O , specifically, Done on the street.

The slip ratio S of the tire mounted on the drive wheel can be expressed as S = (V _D -V) / V.

When the current longitudinal acceleration G _{X (n)} clipped to the maximum longitudinal acceleration G _{XM (n)} is _{equal to or larger} than the filtered previous longitudinal acceleration G _{XF (n-1)} , that is, the vehicle is accelerated. When continuing, the corrected longitudinal acceleration G _{XF (n) is set} to G _{XF (n)} = 28 · Σ {G _{X (n)} −G _{XF (n-1)} } / 256, and noise is removed by delay processing. , The corrected longitudinal acceleration G _{XF (n)} is made to follow the longitudinal acceleration G _{X (n)} clipped to the maximum longitudinal acceleration G _{XM (n)} relatively quickly.

On the contrary, if the current longitudinal acceleration G _{X (n)} clipped to the maximum longitudinal acceleration G _{XM (n)} is less than the previous corrected longitudinal acceleration G _{XF (n-1)} , that is, the vehicle accelerates too much. If not, the following processing is performed every sampling cycle of the main timer.

When the slip control flag F _S is not set, that is, when the drive torque of the engine 11 is not reduced by the slip control, the vehicle is decelerating, so that G _{XF (n)} = G _{XF (n- 1) As} -0.002, the reduction of the corrected longitudinal acceleration G _XF is suppressed, and the responsiveness to the driver's acceleration request of the vehicle is secured.

Further, even when the slip amount s is positive when the drive torque of the engine 11 is reduced by the slip control, that is, when the front wheels 59R and 59L are slightly slipped,
Since the vehicle is in deceleration, there is no problem in safety. Therefore, G _{XF (n)} = G _{XF (n-1)} -0.002 is set to suppress the decrease in the corrected longitudinal acceleration G _XF , and the driver's It ensures responsiveness to acceleration requests.

Further, the maximum value of the corrected longitudinal acceleration G _XF is maintained when the slip amount s of the drive wheels described later is negative while the drive torque of the engine 11 is being reduced by the slip control, that is, when the vehicle is decelerating. The responsiveness to the driver's acceleration request of the vehicle is ensured.

Similarly, while the drive torque of the engine 11 is being reduced by the slip control, while the hydraulic transmission is being shifted up by the automatic transmission 13, it is necessary to secure a feeling of acceleration of the vehicle to the driver. The maximum value of the corrected longitudinal acceleration G _XF is held, but it is also possible to gradually increase the corrected longitudinal acceleration G _XF during this period. By this filter operation, it is possible to improve the feeling of acceleration immediately after the shift is completed.

In this way, the corrected longitudinal acceleration G _XF from which noise has been removed by the filter unit 204 is converted into the torque conversion unit 207.
Although the torque conversion is performed by the above, the filter operation described above may be performed after the torque conversion by the torque conversion unit 207.

Since the value calculated by the torque conversion unit 207 should be a positive value as a matter of course, the clipping unit 208 clips this value to 0 or more in order to prevent a calculation error. After that, the running resistance T _R calculated by the running resistance calculation unit 209 is added by the addition unit 210, and further calculated by the cornering drag correction amount calculation unit 211 based on the detection signal from the steering angle sensor 90. The cornering drag correction torque T _C is added by the adder 212, and the following formula (3) is used.
The reference drive torque T _B shown in is calculated. T _B = G _XF · W _b · r + T _R + T _C (3) where W _b is the vehicle body weight and r is the effective radius of the driving wheels. It corresponds to the reference drive torque setting means of the invention.

As is clear from the equation (3), the reference driving torque T _B is set smaller as the estimated lateral acceleration G _YE becomes larger due to the action of the upper limit clip portion 205. By subtracting the feedback correction torque from the reference drive torque T _B , a sufficient feedback correction effect can be obtained, and the target drive torque T _O of the engine 11 can be effectively achieved even in a four-wheel drive type vehicle. It is possible to reduce.

The running resistance T _R can be calculated as a function of the vehicle speed V, but in the present embodiment, it is obtained from the map shown in FIG. In this case, since the running resistance T _R is different between the flat road and the uphill road, the maps for the flat road indicated by the solid line and the uphill road indicated by the chain double-dashed line are written in the map and are incorporated in the vehicle. Although either one is selected based on the detection signal from the tilt sensor (not shown), the traveling resistance T _{R is} further finely included including the downhill.
It is also possible to set.

Further, in this embodiment, the cornering drag correction torque T _C is obtained from the map as shown in FIG. 19, and the engine 11 that approximates the actual running state is obtained by this.
It can be set in the reference driving torque T _B, since the reference driving torque T _B of the turning immediately after the engine 11 is in the large, acceleration feeling of the vehicle after exiting the turning path is improved.

[0098] Incidentally, the (3) with respect to the reference driving torque T _B is calculated by the equation, by the present embodiment to set the minimum value T _BL in the variable clip portion 213, the from the reference driving torque T _B This prevents a problem that the value obtained by subtracting the final correction torque T _PID , which will be described later, as the feedback correction torque by the subtraction unit 214 becomes negative. As shown in the map shown in FIG. 20, the minimum value T _BL of the reference drive torque T _B is gradually reduced according to the elapsed time from the start of slip control.

On the other hand, the ECU 14 controls the front and rear wheel rotation sensor 93.
Based on the detection signals from R, 93L, 94R, and 94L, the drive wheel speed calculation unit 215 sets the drive wheel speed V _D from the average of the data of the largest and the next largest value, while the vehicle speed V After setting the target drive wheel speed V _FS for correction torque calculation based on the target drive wheel speed V _FO calculated from
The target drive wheel speed V _FS for calculating the correction torque is set to the drive wheel speed V _D.
The target drive torque T _O of the engine 11 is calculated by performing feedback control of the reference drive torque T _B by using the slip amount s obtained by subtracting from the reference drive torque T _B.

By the way, in order to make effective use of the drive torque generated in the engine 11 during acceleration of the vehicle, as shown by the solid line in FIG. 17, the slip ratio S of the tires mounted on the drive wheels during traveling is The maximum value of the friction coefficient between the tire and the road surface is adjusted so that the target slip ratio S _O corresponding to the maximum value or a value smaller than the target slip ratio S 0 is set to a value smaller than this value to avoid energy loss and impair the steering performance and acceleration performance of the vehicle. It is desirable not to.

Here, it is known that the target slip ratio S _O swings in the range of about 0.1 to 0.25 depending on the condition of the road surface. Therefore, while the vehicle is running, the target slip ratio S _O is 10% with respect to the road surface.
It is desirable to generate a slip amount s on the drive wheels. In consideration of the above points, the target driving wheel speed V _FO is set by the multiplying unit 216 according to the following equation based on the vehicle speed V output from the vehicle speed calculating unit 300. V _FO = 1.1 · V

Then, the ECU 14 reads the slip correction amount V _K corresponding to the above-described corrected longitudinal acceleration G _XF from the map as shown in FIG. 21 by the acceleration correction unit 217, and the addition unit 218 reads this slip correction amount V _K. Add to _FO . The slip correction amount V _K has a tendency to increase stepwise as the value of the corrected longitudinal acceleration G _XF increases, but in the present embodiment, this map is created based on a vehicle running test or the like. is doing.

As a result, the target drive wheel speed V _FS for calculating the correction torque, which will be described later, increases, and the slip ratio S during acceleration is increased.
Is set to a value smaller than the target slip ratio S _O shown by the solid line in FIG. 17 or its vicinity.

On the other hand, as shown by the alternate long and short dash line in FIG.
The slip ratio of the tire having the maximum friction coefficient between the tire and the road surface during turning is the target slip ratio S of the tire having the maximum friction coefficient between the tire and the road surface during straight running.
It turns out that it is considerably smaller than _O. Therefore, it is desirable to set the target drive wheel speed V _FO smaller than when the vehicle is straight ahead so that the vehicle can smoothly turn while the vehicle is turning.

Therefore, the turning correction unit 219 shows the solid line in FIG.
From the map as shown in FIG._YECorresponding to
Slip correction amount V_KCRead out. However, the ignition
First steering after the key switch 96 is turned on
Until the neutral position of the shaft 89 is learned, the steering shaft 89
Turning angle δ_HIs not reliable, the lateral acceleration sensor 92
Corrected lateral acceleration calculated from detection signals from a and 92b
G_YF22 from the map shown by the broken line in FIG.
Slip correction amount V_KCRead out. Estimated lateral acceleration G_YEAgainst
The slip correction amount V_KCIs the driver's steering hand
It is conceivable that the extra 88
G_YEIf the area is small, the corrected lateral acceleration G _YFCorresponding to
Lip correction amount V_KCIt is set smaller than.

In the region where the vehicle speed V is low, it is desirable to ensure the acceleration of the vehicle, and conversely, when the vehicle speed V is above a certain speed, it is necessary to consider the ease of turning. Therefore, the slip correction amount V read from FIG.
_The correction coefficient K _V corresponding to the vehicle speed V is read from _KC in the map shown in FIG.
The corrected slip correction amount V _KF is calculated.

As a result, the target drive wheel speed V _FO for calculating the correction torque decreases, the slip ratio S during turning becomes smaller than the target slip ratio S _O during straight traveling, and the acceleration performance of the vehicle slightly deteriorates. Good turning performance is secured.

In this way, the correction torque calculation target drive wheel speed V _FS is calculated by the subtraction unit 221 according to the following equation. V _FS = V _FO + V _K −V _KF

Next, the subtraction unit 222 subtracts the target drive wheel speed V _FS for calculating the correction torque from the drive wheel speed V _D calculated by the drive wheel speed calculation unit 215 to calculate the slip amount s. .
When the slip amount s is less than or equal to a negative set value, for example, less than or equal to −2.5 km / h, the slip amount s = 2.5 km / h is clipped by the clip unit 223, and the slip amount after the clipping process is performed. s is subjected to a proportional correction described later, and the slip amount s before the clipping process is subjected to an integral correction using an integration constant ΔT _I described later, and further a differential correction is performed to obtain a final correction torque T _PID . calculate.

As the proportional correction, the multiplication unit 224 multiplies the slip amount s by a proportional coefficient K _P to obtain a basic correction amount, and the multiplication unit 225 further calculates the basic correction amount in advance according to the gear ratio ρ _m of the automatic transmission 13. The set correction coefficient ρ _KP (see FIG. 27) is multiplied to obtain the proportional correction torque T _P. The proportional coefficient K _P
24 is read from the map shown in FIG. 24 according to the slip amount s after the clipping process in the clipping unit 223.

Further, in order to realize the correction corresponding to the gradual change of the slip amount s as the integral correction, a basic correction amount is calculated by the integral calculation section 226, and the multiplication section 227 calculates this basic correction amount. And a correction coefficient ρ _KI (see FIG. 27) preset based on the gear ratio ρ _m of the automatic transmission 13,
The integral correction torque T _I is obtained. In this case, in the present embodiment, the integral constant ΔT _I which is a constant minute integral correction torque is integrated, and when the slip amount s is positive for each sampling cycle, the integral constant ΔT _I is added, and conversely the slip occurs. If the quantity s is negative, the integration constant ΔT _I is subtracted.

However, the integral correction torque T _I is equal to the vehicle speed V
The minimum value T _IL as shown in the map of FIG. 25 which is variable according to is set, and by this clipping process, when the vehicle starts,
Particularly when starting uphill, a large integral correction torque T _I is applied to secure the driving force of the engine 11, and after the vehicle speed V increases after starting the vehicle, on the contrary, if the correction is too large, the stability of the control will be improved. Since it is lacking, the integral correction torque T _I is made small. Further, the upper limit on the integral correction torque T _I to enhance the convergence of control, for example, set the 0Kgm, integral correction torque T _I by the clipping process changes as shown in FIG. 26.

The proportional correction torque T _P and the integral correction torque T _I calculated in this way are added by the adder 228 to calculate the proportional integral correction torque T _PI .

The correction coefficients ρ _KP and ρ _KI are set in advance in association with the gear ratio ρ _m of the automatic transmission 13 shown in FIG.
Each is read from the map as shown in FIG.

Further, in the present embodiment, the differential operation unit 229 calculates the slip amount change rate G _S and multiplies this by the differential coefficient K _D.
Multiply at 230 to calculate a basic correction amount for a sudden change in the slip amount s. Then, the upper limit value and the lower limit value are set to the respective values thus obtained, and the clipping process is performed by the clipping unit 231 so that the differential correction torque T _D does not become an extremely large value, and the differential correction torque T _D is set. I'm getting _D. In the clip portion 231, the driving wheel V _D may momentarily become idling or locked depending on road surface conditions, running conditions, etc. while the vehicle is running. In such a case, the slip amount change rate G _S is positive. Alternatively, since the value becomes an extremely large negative value and the control may diverge to lower the responsiveness, for example, the lower limit value is clipped to −55 kgm and the upper limit value is clipped to 55 kgm, and the differential correction torque T _D becomes extremely large. This is to prevent it from becoming a large value.

Thereafter, the adder unit 232 adds the proportional-integral correction torque T _PI and the derivative correction torque T _D, and the final correction torque T _PID obtained by this is added by the subtractor unit 214 to the above-mentioned reference drive torque. Subtract from T _B , and further multiply unit 233
At engine 11 and front wheels 59R, by multiplying the reciprocal of the total reduction ratio between the axles 89 and 90 of 59L, calculates the target driving torque T _O for slip control as shown in the following equation (4). _{T O = (T B -T PID} ) / (ρ m · ρ d · ρ T) ··· (4)

[0117] However, ρ_dIs the differential gear reduction ratio, ρ_TIs the torque
Is the converter ratio, and the automatic transmission 13
When performing a gear shifting operation, change the gear on the high-speed stage side after the gear shifting is completed.
Speed ratio ρ_mIs output. That is, automatic
In the case of an upshift operation of the transmission 13,
The gear ratio ρ on the high-speed stage side when the signal is output_mIs adopted,
As is clear from equation (4) above, the target drive torque
Luk T_OIncreased and the engine 11 blew up
Output the signal to start shifting, and the shifting operation is completed.
For example, for 1.5 seconds, the target drive torque T_OThe smaller
Gear ratio ρ_mIs held and the shift starts
1.5 seconds after the signal is output, the gear ratio ρ on the high-speed stage side_mBut
Adopted. For the same reason, the automatic transmission 13 is down.
In the case of shifting gears, the low
Speed ratio ρ_mWill be immediately adopted.

Target drive torque T _O calculated by the equation (4)
Since it should become a positive value will appreciate that the target driving torque T _O for the purpose of preventing the operation mistake at the clip portion 234 is clipped to 0 or more, for determining the start or end of the slip control According to the determination processing by the start / end determination unit 235, information regarding this target drive torque T _O is output.

The start / end determination unit 235 determines that the slip control is to be started when all of the following conditions (a) to (e) are satisfied, sets the slip control flag F _S, and sets the target drive torque. Print information about T _O, the slip control flag F _S to determine the end of the slip control until the reset, and this process is continued.

(A) The driver desires slip control by operating a manual switch (not shown). (b) The driving torque _Td requested by the driver is the minimum driving torque required to drive the vehicle, for example, 4 kgm or more. In this embodiment, the required drive torque T _d
28 is preset based on the engine rotation speed N _E calculated from the detection signal from the crank angle sensor 87 and the accelerator opening θ _A calculated from the detection signal from the accelerator opening sensor 76. It is read from such a map. (c) The slip amount s is 2 km / h or more. (d) The slip amount change rate G _S is 0.2 g or more. (e) The drive wheel acceleration G _D obtained by differentiating the drive wheel speed V _D with respect to time by the differentiating unit 236 is 0.2 g or more.

On the other hand, after the start / end judging unit 235 judges that the slip control is started, if one of the following conditions (f) and (g) is satisfied, it is judged that the slip control is completed. Then, the slip control flag F _S is reset and the transmission of the target drive torque T _O is stopped.

(F) The target drive torque T _O is equal to or greater than the required drive torque T _d , and the slip amount s is a constant value, for example, −2 km / h or less, for a fixed time, for example, 0.5 seconds or longer There is. (g) The state where the idle switch 95 is changed from off to on, that is, the state where the driver releases the accelerator pedal 30 continues for a certain time, for example, 0.5 seconds or more.

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

FIG. 2 showing the flow of this slip control process.
As shown in FIG. 9, the ECU 14 calculates the target drive torque T _O by the detection and calculation processing of various data described above in step S1, but this calculation operation is performed regardless of the operation of the manual switch.

[0125] Next, first slip control flag F _S at S2 in step determines whether it is set, because the first slip control flag F _S is not set, S3 step of ECU14 At, it is determined whether the slip amount s of the driving wheels is larger than a preset threshold value, for example, 2 km / hour.

If it is determined in step S3 that the slip amount s is greater than 2 km / h, the ECU 14 determines in step S4 whether the slip amount change rate G _S is greater than 0.2 g.

If it is determined in step S4 that the slip amount change rate G _S is larger than 0.2 g, the ECU 14 determines in step S5 that the drive torque T _d required by the driver is required to drive the vehicle. Minimum drive torque, eg 4kg
It is determined whether or not it is larger than m, that is, whether or not the driver intends to drive the vehicle.

At the step S5, the required drive torque T
_d is greater than 4Kgm, i.e. when the driver determines that there is intention to drive the vehicle, is set through the slip control flag F _S at step S6, the slip control flag F _S is set at step S7 It is again determined whether or not it has been done.

When it is determined in step S7 that the slip control flag F _S is being set, the target drive torque T _O of the engine 11 is set as the above in step S8.
The target drive torque T _O for slip control calculated in advance by the equation (4) is adopted.

If it is determined in step S7 that the slip control flag F _S has been reset, the ECU 14 determines in step S9 that the target drive torque T
The maximum torque of the engine 11 is output as _O , and E
As a result of the CU 14 reducing the duty ratio of the torque control solenoid valves 50, 55 to the 0% side, the engine 11 generates a drive torque according to the amount of depression of the accelerator pedal 30 by the driver.

When it is determined in step S3 that the slip amount s of the driving wheels is smaller than 2 km / h, or in step S4 that the slip amount change rate G _S is smaller than 0.2 g. Alternatively, if it is determined in step S5 that the required drive torque T _d is smaller than 4 kgm, the process proceeds to step S7, and in step S9, the ECU 14 sets the target drive torque T _o as the maximum of the engine 11. As a result of outputting torque, and the ECU 14 lowering the duty ratio of the torque control solenoid valves 50, 55 to the 0% side, the engine 11 generates a drive torque according to the amount of depression of the accelerator pedal 30 by the driver.

On the other hand, when it is determined in step S2 that the slip control flag F _S is set, in step S10 the slip amount s of the drive wheels is equal to or less than the threshold value of −2 km / h. And the required drive torque T _d is equal to or less than the target drive torque T _O calculated in the step S1 is continued for 0.5 seconds or longer.

At step S10, the slip amount s is smaller than −2 km / h and the required drive torque T _d is equal to or less than the target drive torque T _O for 0.5 seconds or more.
That is, if the driver determines that he / she does not already desire to accelerate the vehicle, the slip control flag F _S is determined in step S11.
Is reset and the process proceeds to step S7.

In the step S10, the slip amount s is larger than −2 km / h, or the required drive torque T _d
If the driver does not continue the target drive torque T _O or less for 0.5 seconds or more, that is, if the driver wants to accelerate the vehicle, the ECU 14 turns on the idle switch 95 in step S12, that is, It is determined whether the fully closed state of the throttle valve 19 continues for 0.5 seconds or more.

If it is determined in step S12 that the idle switch 95 is on, the driver has not stepped on the accelerator pedal 30, so the process proceeds to step S11 to reset the slip control flag F _S. . On the other hand, when it is determined that the idle switch 95 is off, the driver depresses the accelerator pedal 30, so the process proceeds to step S7 again.

[0136]

According to the present invention as described in detail with reference to the embodiments, the estimated vehicle speed calculated based on the longitudinal acceleration or the reference which is the predetermined speed from the faster one of the four wheel speeds. One of the wheel speeds is set as the traveling speed of the vehicle. Further, the reference wheel acceleration obtained by differentiating the reference wheel speed is compared with the one obtained by adding the comparison variable (α) to the longitudinal acceleration, and when the former becomes larger, the vehicle speed is switched from the reference wheel speed to the estimated vehicle speed. Furthermore, the estimated vehicle speed is compared with the reference wheel speed, and when the former becomes larger, the vehicle speed is returned from the estimated vehicle speed to the reference wheel speed. In this case, since the comparison variable (α) is made larger during turning, as compared to during straight running, switching from the reference wheel speed to the estimated vehicle speed is less likely to occur during turning. The estimated vehicle speed tends to be disturbed when turning, so switching is made difficult to improve accuracy. By controlling the output of the vehicle by using the vehicle speed thus obtained, stable running without slip can be performed.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an intake / exhaust system part in an embodiment in which a vehicle output control device according to the present invention is applied to a four-wheel drive type vehicle incorporating a hydraulic automatic transmission having four forward gears and one reverse gear. Is.

FIG. 2 is a conceptual diagram of a drive system portion in the present embodiment.

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

FIG. 4 is a hydraulic control circuit diagram in the present embodiment for a hydraulic multi-plate clutch assembled to a center differential.

FIG. 5 is a hydraulic control circuit diagram of a portion of the pressure control valve.

FIG. 6 is a graph showing the relationship between the engagement pressure of the hydraulic multi-plate clutch and the duty ratio of the clutch control solenoid valve in the present embodiment.

FIG. 7 is a flowchart showing the overall flow of control in this embodiment.

FIG. 8 is a graph showing the relationship between lateral acceleration and steering angle ratio.

9 is a block diagram showing a calculation procedure of a target drive torque for slip control in the present embodiment together with FIG.

FIG. 10 is a block diagram showing a calculation procedure of a target drive torque for slip control in the present embodiment together with FIG.

FIG. 11 is a block diagram showing a vehicle speed calculation unit.

FIG. 12 is a characteristic diagram showing characteristics of a variable β used in an equation for calculating an estimated vehicle speed when the turning angle of the steering shaft is less than 180 degrees.

FIG. 13 is a characteristic diagram showing characteristics of a variable β used in an equation for calculating an estimated vehicle speed when the turning angle of the steering shaft is 180 degrees or more.

FIG. 14 is a characteristic diagram showing a characteristic of a variable α used when performing a comparison calculation between the acceleration obtained by the acceleration sensor and the reference wheel acceleration.

FIG. 15 is a flowchart showing a procedure for selecting an estimated lateral acceleration and a corrected lateral acceleration in this embodiment.

FIG. 16 is a map showing the relationship between the estimated lateral acceleration and the maximum longitudinal acceleration in this embodiment.

FIG. 17 is a graph showing the relationship between the friction coefficient between the tire mounted on the drive wheel and the road surface and the slip ratio of the tire.

FIG. 18 is a map showing the relationship between vehicle speed and running resistance in the present embodiment.

FIG. 19 is a map showing the relationship between the turning angle of the steering shaft and the cornering drag correction torque in this embodiment.

FIG. 20 is a map showing the relationship between the control start elapsed time and the minimum value of the reference drive torque in the present embodiment.

FIG. 21 is a map showing the relationship between the corrected longitudinal acceleration and the slip correction amount in this embodiment.

FIG. 22 is a map showing the relationship between lateral acceleration and slip correction amount in this embodiment.

FIG. 23 is a map showing the relationship between the vehicle speed and the correction coefficient for the slip correction amount in the present embodiment.

FIG. 24 is a map showing the relationship between the slip amount and the proportional coefficient in the present embodiment.

FIG. 25 is a map showing the relationship between the vehicle speed and the minimum value of integral correction torque in this embodiment.

FIG. 26 is a graph showing a change state of integral correction torque in the present embodiment according to a slip amount.

FIG. 27 is a map showing the relationship between each shift speed of the automatic transmission according to the present embodiment and the correction coefficient corresponding to the correction torque.

FIG. 28 is a map showing a relationship among an engine rotation speed, a required drive torque, and an accelerator opening degree in the present embodiment.

FIG. 29 is a flowchart showing the flow of slip control in the present embodiment.

[Explanation of symbols]

 11 is an engine, 12 is a torque converter, and 13 is automatic shifting
Machine, 14 is ECU, 15 is air cleaner, 16 is combustion
Chamber, 17 intake pipe, 18 intake passage, 19 throttle
Valve, 20 is throttle body₁21 is a throttle shaft, 2
2 is the accelerator lever, 23 is the throttle lever, 24 is
Cylindrical part, 25 is a bush, 26 is a spacer, 27 is a washer, 2
8 is a nut, 29 is a cable receiver, 30 is an accelerator pedal
, 31 is a cable, 32 is a collar, 33 is a claw, 34
Is a stopper, 35 is a torsion coil spring, and 36 and 37 are
Receptacle, 38 is a stopper pin, 39 is a torsion coil
40 is an actuator, 41 is a diaphragm, 42
Is a control rod, 43 is a pressure chamber, 44 is a compression coil spring, and 45 is
Is a surge tank, 46 is a connecting pipe, 47 is a vacuum tank
Link, 48 is a check valve, 49 is piping, and 50 is torque control.
Solenoid valve, 51 is a plunger, 52 is a valve seat, and 53 is a valve.
54 is piping, 55 is a solenoid valve for torque control, and 56 is
Runner, 57 is a spring, 58 is an output shaft, 59R, 59L are
Front wheels, 60R, 60L are rear wheels, 61 is a center differential, 62
Is an intermediate gear, 63 is a sun gear, 64 is a planetary gear, and 65 is
Internal gear, 66 is a planet carrier, 67 is an output shaft for front wheels,
68 is a reduction gear, 69 is a front differential, and 70 is a rear wheel output.
Force shaft, 71 is a bevel gear group, 72 is a propeller shaft, 73R, 73
L is the front axle, 74 is the bevel gear group, and 75 is the rear differential.
Shall, 76R, 76L rear axle, 77 is hydraulic multi-plate crack
H, 78 is oil sump, 79 is oil pump, 80 is pressure control
Valve, 801 is land, 802 is land, 803 is spool, 804 is
Return spring, 81 is pressure switch, 82 is relief valve, 8
3 is a reducing valve, 831 is a land, 832 is a land, 83
3 is a spool, 834 is a return spring, and 84 is an electric power for clutch control.
Magnetic valve, 841 solenoid, 842 valve body, 843 return spring, 8
5 is a throttle opening sensor, 86 is an accelerator opening sensor
A reference numeral 87, a crank angle sensor, 88 a steering wheel, 8
9 is a steering shaft, 90 is a steering angle sensor, and 91 is a longitudinal acceleration sensor.
Sensors, 92a and 92b are lateral acceleration sensors, and 93R and 93L are front
Wheel rotation sensor, 94R, 94L are rear wheel rotation sensor, 95 is
Idle switch, 96 is ignition key switch
H, 101 is an oil passage, 102 is a branch oil passage, 103 is an oil discharge passage, 104 is oil
Passage, 105 is an oil passage, 106 is an oil discharge passage, 107 is an oil passage, 108 is an orifice
, 109 is control oil passage, 110 is drain oil passage, 202 is estimated lateral acceleration
Degree calculation unit, 203 lateral acceleration calculation unit, 204 filter unit, 20
5 is the upper limit clip part, 206 is the filter part, 207 is the torque conversion
Calculation unit, 208 is a clip unit, 209 is a running resistance calculation unit, and 210 is
An adder 211 is a cornering drag correction amount calculator 212
Is an addition unit, 213 is a variable clip unit, 214 is a subtraction unit, and 215 is
Drive wheel speed selection unit, 216 is a multiplication unit, 217 is an acceleration correction unit, 21
8 is an addition unit, 219 is a turning correction unit, 220 is a multiplication unit, and 221 is a subtraction unit.
Section, 222 is a subtracting section, 223 is a clipping section, 224 is a multiplying section, 225
Is a multiplication unit, 226 is an integration calculation unit, 227 is a multiplication unit, and 228 is addition.
Section, 229 is a differential operation section, 230 is a multiplication section, and 231 is a clip
Section, 232 is addition section, 233 is multiplication section, 234 is clip section, 235
Is a start / end determination unit, and 236 is a differential operation unit. 300 is a car
Speed calculation unit, 301 is a filter, 302 is a peak hold unit, 30
3 is a switch unit, 304 is an estimated vehicle speed calculation unit, and 305 is a vehicle speed selection
Output unit, 306 is a reference wheel speed selection unit, 307 is a differentiation unit, 308 is
A filter unit, 309 is a comparison unit, and 310 is a comparison unit. Also, A
Is the stability factor, F_SIs the slip control
G, G_sIs the rate of change in slip amount, G_XIs the longitudinal acceleration, G_XFIs
Modified longitudinal acceleration, G_XfIs the filter longitudinal acceleration, G_XfPIs
Peak hold longitudinal acceleration, G_XSWIs switch forward / backward acceleration
Degree, G₃Is the reference wheel acceleration, G_3fIs the filter reference wheel addition
Speed, G_YIs the lateral acceleration, G_YFIs the corrected lateral acceleration, G_YEIs recommended
Constant lateral acceleration, K_DIs the derivative coefficient, K_PIs the proportional coefficient, N_EIs an opportunity
Seki rotation speed, S is the tire slip rate, S_OIs the target pickpocket
Up ratio, s is slip amount, T_BIs the reference drive torque, T_BL
Is the minimum value of the reference drive torque, T_CIs cornering drag
Correction torque, T_DIs the differential correction torque, T_dIs demand-driven
Luk, T_IIs the integral correction torque, T_ILIs the integral correction torque
Minimum value, T_OIs the target drive torque, T_PIs the proportional correction torque,
T_PIIs the proportional-integral correction torque, T_PIDIs the final correction torque,
T_RIs the running resistance, ΔT _IIs an integration constant, V is a vehicle speed, V_DDrive
Wheel speed, V_FOIs the target drive wheel speed, V_FSIs for correction torque calculation
Target drive wheel speed, V_KIs the slip correction amount, V_KCIs slip
Correction amount, V₃Is the reference wheel speed, V_BIs the estimated vehicle speed, δ_HIs turning
Angle, θ_AIs the accelerator opening, ρ_dIs the differential gear reduction ratio, ρ_KIIs
Correction factor, ρ_KPIs the correction factor, ρ_mIs the shift of the automatic transmission
Ratio, ρ_TIs the torque converter ratio.

Claims (1)

[Claims] 1. Torque reducing means for reducing a driving torque of an engine mounted on the vehicle, independently of an operation by a driver who drives a four-wheel drive type vehicle, and before and after detecting acceleration in the longitudinal direction of the vehicle. Acceleration detection means, reference drive torque setting means for setting a reference drive torque serving as a reference of the engine based on the longitudinal acceleration detected by the longitudinal acceleration detection means, longitudinal acceleration, turning angle of the steering shaft, and each wheel Vehicle speed calculation means for calculating the running speed of the vehicle based on the rotation speed, and the difference between the running speed of the vehicle and the average speed of the rotation speeds of each wheel is regarded as the slip amount, and based on this slip amount Target drive torque setting means for obtaining a correction torque and further setting a target drive torque by subtracting the correction torque from the reference drive torque; and the drive torque of the engine is the target drive torque. Thus, in the vehicle output control device having an electronic control unit for controlling the operation of the torque reduction means, the vehicle speed calculation means comprises: (1) an estimated vehicle speed for calculating an estimated vehicle speed based on longitudinal acceleration. A calculation unit; (2) a reference wheel speed selection unit that outputs the predetermined one of the rotation speeds of the wheels from the earliest as the reference wheel speed; and (3) one of the estimated vehicle speed and the reference wheel speed And a vehicle speed selection output unit for outputting as a vehicle speed, (4) the reference wheel acceleration obtained by differentiating the reference wheel speed becomes larger than the value obtained by adding the variable for comparison to the longitudinal acceleration, the vehicle speed in the vehicle speed selection output unit, A first comparing section for switching from the reference wheel speed to the estimated vehicle speed; and (5) a second comparison section for returning the vehicle speed in the vehicle speed selection output section from the estimated vehicle speed to the reference wheel speed when the estimated vehicle speed becomes larger than the reference wheel speed. It has a comparison part, Moreover, in the first comparison unit, the output variable control device for a vehicle is characterized in that the comparison variable is small when the turning angle of the steering shaft is smaller than a predetermined angle and is large when the turning angle is larger than the predetermined angle.