JP2596177B2 - Vehicle steering angle neutral position learning method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle steering angle neutral position learning method used for accurately performing turning control and slip control of a vehicle.

<Conventional technology> A centrifugal force, that is, a lateral acceleration according to the traveling speed is generated in a vehicle traveling in a circuit in a direction perpendicular to the traveling direction.

For this reason, if the traveling speed with respect to the radius of curvature of the circuit is too high, the wheels may skid and jump out onto the sidewalk or oncoming lane, or in the worst case, overturning. Therefore, immediately before the circuit, the driver once lowers the running speed and performs so-called slow-in first-out running in which the vehicle accelerates slowly. However, there is a case where the radius of curvature is gradually reduced in a circuit such as a blind curve in which an exit cannot be confirmed, and in such a case, an extremely advanced operation technique is required.

On the other hand, there is a vehicle having an under-steering tendency in which, when the vehicle is accelerated from a steady circular turning state, the traveling locus is large while the steering angle is constant. In such a vehicle, it is necessary to gradually increase the steering angle with an increase in the lateral acceleration. However, when the lateral acceleration exceeds a certain value (limit value) specific to the vehicle, an understeering tendency is suddenly produced, and steering becomes difficult. It is known that it becomes impossible or completely impossible. As a typical example of such a vehicle, there is a so-called FF vehicle having a front engine and a front drive in which the steered wheels and the drive wheels are the same.
Because of its superiority in terms of size, etc., F / F vehicles are becoming mainstream in passenger cars and the like.

In order to prevent the lateral acceleration from exceeding the limit value, it is fundamental that the driver knows the radius of curvature of the circuit and adjusts the driving force with the accelerator pedal. However,
It is very difficult for an inexperienced driver to delicately control the amount of depression of the accelerator pedal by the aforementioned blind curve or the like.

In view of such circumstances, various driving force control devices have been proposed that automatically reduce the driving force before the vehicle becomes difficult to turn or cannot turn. Many of these devices reduce the output of the engine according to, for example, the amount of rolling of the vehicle body without being linked to the amount of depression of the accelerator pedal. In other words, rolling due to lateral acceleration always occurs during turning, but as the turning radius is smaller and the running speed is higher, the amount of rolling is larger, so this is determined by the height sensors provided on the left and right sides of the vehicle body. Thus, the output is detected and the output is reduced. In addition, there is a method of detecting the yaw amount, which is a swing phenomenon of the vehicle body, to reduce the output.

<Problem to be Solved by the Invention> In the driving force control device as described above, after rolling or the like actually occurs, TCL (T
The raction Calculate Unit calculates the optimal drive torque and controls the engine output with an ECU (Electronic Control Unit).

However, such a control device has the following disadvantages. For example, in a situation where the rolling is rapidly increasing, a so-called hunting operation is repeated in which the output control is delayed or the output is further controlled by releasing the control after the rolling is stopped and the rolling is generated again. Was caused.

For this reason, control devices that perform driving force control based on running speed, steering angle, and the like and stability factors (eigenvalues obtained from suspension, tire rigidity, and the like) have been spotlighted. In this driving force control device, data at the moment when the driver turns the steering wheel is input to the ECU, so that it is possible to control the engine output (so-called anticipation control) before excessive rolling or the like occurs. The steering angle that is indispensable for this control is usually based on the steering axis stored in RAM (Random Access Memory), that is, the neutral position of the front wheels, and the amount of deviation from the neutral position is determined by the slit plate attached to the steering axis and the phototransistor. It is detected by a steering angle sensor using the like and input to the ECU.

However, as is well known, the steering amount for fully steering the steering wheel, that is, the number of rotations of lock-to-lock is several rotations (generally 2.5 to 3 rotations). Therefore, even if a slit or the like at the neutral point is formed in the slit plate of the steering angle sensor, the neutral position is normal when the vehicle is stationary or the like with the battery or wiring removed (for example, during maintenance). In one rotation. In addition, the neutral position of the steering shaft itself and the neutral position of the front wheels naturally change when gears in the steering device rub or when toe-in adjustment is performed during maintenance. Therefore, the turning angle of the steering wheel and the actual steering angle sometimes differ on a small order.

When the vehicle is driven in such a state, the power control is not performed when it should be performed, and the power is reduced by simply turning the steering wheel lightly, and the driver can drive as intended. Something has gone wrong.

The present invention has been made in view of the above situation, and has as its object to provide a steering angle neutral position learning method capable of learning and correcting the neutral position of a steering shaft by itself while traveling, and supplying accurate steering angle data to an ECU. I do.

<Means for Solving the Problems> A configuration of the present invention that solves the above problems includes: a steering angle sensor that detects a steering angle; and a position that is attached to the steering wheel and the rotational position of the steering wheel corresponds to a straight traveling state of the vehicle. A reference position sensor for detecting whether or not the vehicle is in the vehicle, and running speed detecting means for detecting each vehicle of the left and right wheels and a vehicle speed. If the vehicle speed is equal to or higher than the established vehicle speed and the wheel speed difference between the left and right wheels is equal to or less than the set wheel speed difference for a first set time or longer, the steering is performed. It is determined that the current steering angle detected by the angle sensor is the neutral position, and the steering shaft reference position sensor detects that the turning position of the steering wheel is at a position corresponding to the straight traveling state of the vehicle. When the vehicle speed is equal to or higher than the set vehicle speed and the wheel speed difference between the left and right wheels is equal to or smaller than the set wheel speed difference for more than a second set time shorter than the first set time, detection is performed by the steering angle sensor. The present steering angle is determined to be the neutral position.

The “steering shaft reference position sensor” is a sensor attached to the steering wheel and detects whether the turning position of the steering wheel is at a position corresponding to the straight traveling state of the vehicle.

The “relationship between the detected value of the steering angle sensor and the detected value of the steering axis reference position sensor” is as follows. That is, in order to correct the detection error of the steering angle sensor, the neutral position of the steering angle is normally corrected using the detection value of the steering axis reference position sensor. , The detection error of the steering angle sensor is corrected.

<Operation> Even if the neutral position information in the RAM is erased or goes wrong due to a stop or maintenance, if the vehicle travels straight ahead at a predetermined speed for a predetermined time, the rotation angle of the rotating member, that is, the steering shaft at that point in time. Is learned as the neutral position, and thereafter, the steering angle of the vehicle is calculated based on the angular displacement from the neutral position.

<Embodiment> FIG. 1 showing the concept of an embodiment in which a vehicle output control device according to the present invention is applied to a front-wheel drive type vehicle incorporating an automatic transmission of four forward steps and one reverse step, and its bath capacity. 2, the output shaft 12 of the engine 11 is connected to the input shaft 14 of the hydraulic automatic transmission 13. As shown in FIG. The hydraulic automatic transmission 13 includes an electronic control unit (hereinafter, referred to as an ECU) 15 that controls an operation state of the engine 11 in accordance with a driver's selection position of a select lever (not shown) and a vehicle operation state. And automatically selects a predetermined gear position based on the command from the hydraulic control device 16. The specific configuration and operation of the hydraulic automatic transmission 13 are described in, for example, JP-A-58-54270 and JP-A-61-3
As is well known in, for example, US Pat.
A pair of shift control solenoid valves (not shown) for performing an engagement operation and a release operation of a plurality of friction coefficient engagement elements constituting a part of the hydraulic automatic transmission 13 are incorporated therein. ON / OFF operation of energization for solenoid valve for EC
By performing control by U15, a shift operation to an arbitrary speed stage among four forward speeds and one reverse speed is smoothly achieved.

In the middle of the intake pipe 18 connected to the combustion chamber 17 of the engine 11,
A throttle body 21 incorporating a throttle valve 20 for changing the opening degree of an intake passage 19 formed by the intake pipe 18 and adjusting the amount of intake air supplied into the combustion chamber 17 is provided. As shown in FIG. 1 and FIG. 3 showing an enlarged cross-sectional structure of a portion of the throttle body 21 having a cylindrical shape,
Both ends of a throttle shaft 22 to which a throttle valve 20 is integrally fixed are rotatably supported on the throttle body 21. An accelerator lever 23 and a throttle lever 24 are coaxially fitted to one end of the throttle shaft 22 projecting into the intake passage 19.

A bush 26 and a spacer 27 are interposed between the throttle shaft 22 and the cylinder portion 25 of the accelerator lever 23, whereby the accelerator lever 23 is rotatable with respect to the throttle shaft 22. Further, a washer 28 and a nut 29 attached to one end speed of the throttle shaft 22 prevent the accelerator lever 23 from coming off from the throttle shaft 22 in advance. Also, a cable receiver 30 integrated with the accelerator lever 23 is provided.
In this case, an accelerator pedal 31 operated by the driver is connected via a cable 32, and the accelerator lever 23 rotates with respect to the throttle shaft 22 according to the amount of depression of the accelerator pedal 31. ing.

On the other hand, the throttle lever 24 is fixed integrally with the throttle shaft 22, so that by operating the throttle lever 24, the throttle valve 20
It rotates with it. A collar 33 is coaxially and integrally fitted to the cylindrical portion 25 of the accelerator lever 23, and is engaged with a claw portion 34 formed at a part of the collar 33 at the tip of the throttle lever 24. A stopper 35 is formed.
The pawl portion 34 and the stopper 35 are engaged with each other when the throttle lever 24 is turned in the direction in which the throttle valve 20 opens or the accelerator lever 23 is turned in the direction in which the throttle valve 20 closes. Is set in a proper positional relationship.

Between the throttle body 21 and the throttle lever 24, a torsion coil spring 36 for pressing the stopper 35 of the throttle lever 24 against the claw portion 34 of the collar 33 integral with the accelerator lever 23 to urge the throttle valve 20 in the opening direction is provided. Are a pair of cylindrical spring supports 37, 3 fitted to the throttle shaft 22.
It is mounted coaxially with the throttle shaft 22 through 8. The collar 33 is also provided between a stopper pin 39 protruding from the throttle body 21 and the accelerator lever 23.
The tongue 34 is pressed against the stopper 35 of the throttle lever 24 to urge the throttle valve 20 in the closing direction, and a torsion coil spring 40 for giving a detent feeling to the accelerator pedal 31 is actuated by the accelerator 33 via the collar 33. The lever 23 is mounted coaxially with the throttle shaft 22 on the cylindrical surface 25 of the lever 23.

The distal end of the throttle lever 24 is connected to the distal end of a control rod 43 whose base end is fixed to the diaphragm 42 of the actuator 41. It is formed inside this actuator 41. Pressure chamber formed in this actuator 41
A compression coil spring 45 is mounted on the compression coil spring 44 for pressing the stopper 35 of the collar 33 together with the torsion coil spring 36 against the claw 34 of the accelerator lever 23 to urge the throttle valve 20 in the opening direction. The spring force of the torsion coil spring 40 is set to be larger than the sum of the spring forces of these two springs 36 and 45, so that the throttle valve 20 does not open unless the accelerator pedal 31 is depressed. ing.

A connection pipe 47 is connected to a surge tank 46 which is connected to the downstream side of the throttle body 21 and forms a part of the intake passage 19.
And a connection between the vacuum tank 48 and the connecting pipe 47 is provided with a non-return valve 49 that allows only the movement of air from the vacuum tank 48 to the surge tank 46. . As a result, the pressure in the vacuum tank 48 is set to a negative pressure substantially equal to the lowest pressure in the surge tank 46.

The inside of the vacuum tank 48 and the actuator 41
The pressure chamber 44 is in communication with the pressure chamber 44 via a pipe 50. In the middle of the pipe 50, a non-energized first torque control solenoid valve 51 is provided. In other words, the torque control solenoid valve 51 is closed by the plunger 52 so that the pipe 50 is closed.
A spring 54 that urges the valve seat 53 is incorporated.

A pipe 55 communicating with the intake passage 19 upstream of the throttle valve 20 is connected to a pipe 50 between the first torque control solenoid valve 51 and the actuator 41. In the middle of the pipe 55, a non-energized second torque control solenoid valve 56 is provided. That is, a spring 58 for urging the plunger 57 to open the pipe 55 is incorporated in the torque control solenoid valve 56.

The two torque control solenoid valves 51 and 56 have the ECU 15
Are connected to each other, and duty on / off of energization to the torque control solenoid valves 51 and 56 is controlled based on a command from the ECU 15. Means.

For example, when the duty ratio of the torque control solenoid valves 51 and 56 is 0%, the pressure chamber 44 of the actuator 41 has an atmospheric pressure substantially equal to the pressure in the intake passage 19 on the upstream side of the throttle valve 20, and the throttle valve 20 The opening of the accelerator pedal 31
One-to-one correspondence with the amount of depression. Conversely, when the duty ratios of the torque control solenoid valves 51 and 56 are 100%, the pressure chamber 44 of the actuator 41 has a negative pressure substantially equal to the pressure in the vacuum tank 48, and the control rod 43 is at the left in FIG. As a result of being lifted diagonally upward, the throttle valve 20 is
It is closed irrespective of the amount of depression of 31 and the drive torque of the engine 11 is forcibly reduced. In this way, by adjusting the duty ratio of the torque control solenoid valves 51 and 56, the opening degree of the throttle valve 20 is changed regardless of the depression amount of the accelerator pedal 31, and the drive torque of the engine 11 is arbitrarily adjusted. can do.

In this embodiment, the opening of the throttle valve 20 is controlled simultaneously by the accelerator pedal 31 and the actuator 41.However, two throttle valves are arranged in series in the intake passage 19, and one throttle valve is connected to the accelerator pedal. It is also possible to connect only the pedal 31 and connect the other throttle valve only to the actuator 41, and control these two throttle valves independently.

On the other hand, at the downstream end side of the intake pipe 18, the combustion chamber of the engine 11
A fuel injection nozzle 59 for injecting fuel (not shown) into the fuel injection device 17 is provided for each cylinder of the engine 11 (in this embodiment, a four-cylinder internal combustion engine is assumed). Fuel is supplied to the fuel injection nozzle 59 through the controlled solenoid valve 60. That is, by controlling the valve opening time of the solenoid valve 60, the amount of fuel supply to the combustion chamber 17 is adjusted, and the combustion chamber 17
It is ignited by a spark plug 61 inside.

The ECU 15 includes a crank angle sensor 62 attached to the engine 11 for detecting an engine speed, and a pair of left and right driving wheels that detect the speed of the output shaft 63 of the hydraulic automatic transmission 13. A front wheel rotation sensor 66 for calculating the average peripheral speed of the front wheels 64 and 65, a throttle opening sensor 67 attached to the throttle body 21 for detecting the opening of the throttle lever 24, and a fully closed state of the throttle valve 20 are provided. In addition to the idle switch 68 to be detected, an air cleaner 69 at the tip of the intake pipe 18
An air flow sensor 70 such as a Karman vortex flow meter that is mounted inside and detects the amount of air flowing to the combustion chamber 17 of the engine 11;
A water temperature sensor 71 attached to the engine 11 to detect a cooling water temperature of the engine 11, and an exhaust temperature sensor attached to the exhaust pipe 72 to detect the temperature of exhaust gas flowing through the exhaust passage 73
74 and the ignition key switch 75 are connected.

The crank angle sensor 62, front wheel rotation sensor 66, throttle opening sensor 67, and idle switch
Output signals from the air flow sensor 68, the air flow sensor 70, the water temperature sensor 71, the exhaust gas temperature sensor 74, and the ignition key switch 75 are sent to the ECU 15.

A torque calculation unit (hereinafter, referred to as TCL) 76 for calculating a target drive torque of the engine 11 is attached to the throttle body 21 together with the throttle opening sensor 67 and the idle switch 68, and is provided with an accelerator lever 23. An accelerator opening sensor 77 that detects the opening, rear wheel rotation sensors 80 and 81 that detect the rotational speeds of a pair of left and right rear wheels 78 and 79 that are driven wheels, respectively, and when turning based on the straight running state of the wheels 82 Steering angle sensor that detects the turning angle of the steering shaft 83 in the vehicle
A steering shaft reference position sensor 86 for detecting a normal phase of every 360 degrees of the steering wheel 85 integrated with the steering shaft 83 (including a phase in which the vehicle 82 is almost in a straight running state) is connected. Output signals from these sensors 77, 80, 81, 84, 86 are sent, respectively.

The ECU 15 and the TCL 76 are connected via a communication cable 87, and the ECU 15 receives a signal from the engine 11 such as an engine speed, a speed of the output shaft 63 of the hydraulic automatic transmission 13, and a detection signal from the idle switch 68. Operating state information is sent to TCL76. Conversely, information about the target drive torque and the ignition timing retard ratio calculated by the TCL 76 is sent from the TCL 76 to the ECU 15.

In the present embodiment, when the amount of slip in the front-rear direction of the front wheels 64, 65, which are drive wheels, becomes larger than a predetermined amount,
The target driving torque of the engine 11 when the control for reducing the driving torque of the engine 11 to secure the maneuverability and prevent the energy loss (hereinafter, referred to as slip control) is performed. When the generated lateral acceleration (hereinafter, referred to as lateral acceleration) is equal to or greater than a preset value, the control is performed to reduce the driving torque of the engine 11 so that the vehicle does not deviate from the circuit. Hereinafter, this is referred to as turning control), and the target drive torque of the engine 11 when performing the rotation is calculated by the TCL 76, and the optimal final target drive torque is selected from these two target drive torques.
The drive torque of the engine 11 can be reduced as necessary. Also, the throttle valve 20 via the actuator 41
The target retardation amount of the ignition timing is set in consideration of the case where the output reduction of the engine 11 cannot
The drive torque of 11 can be reduced quickly.

As shown in FIG. 4 that represents the general flow of control of such embodiment, if in this example, was carried out and the target driving torque T _OS of the engine 11 in the case of performing slip control, the turn control The target drive torque T _OC of the engine 11 is always calculated in parallel by the TCL 76, and these two target drive torques T _OS ,
The optimal final target drive torque T _O is selected from T _OC and the engine 11
The driving torque can be reduced as required.

Specifically, the control program of the present embodiment is started by turning on the ignition key switch 75, and first reads the steering axis turning position initial value δm _(o) at M1, resets various flags, or resets this control. Sanity setting such as the start of counting of the main timer every 15 milliseconds which is a sampling cycle is performed.

Then, based on detection signals from various sensors in M2,
TCL76 calculates a vehicle speed V or the like, this followed by learning correction at the neutral position [delta] _M and M3 of the steering shaft 83. Steering axis of this vehicle 82
Neutral position [delta] _M of 83, because it is not stored in a memory not shown in the ECU15 and TCU76, initial value δ _{m (o)} is read every time the ON operation of the ignition switch 75, vehicle
Learning correction is performed only when 82 satisfies a traveling condition described later, and the initial value Δm _(o) is learned and corrected until the ignition key switch 75 is turned off.

Next, the TCL 76 sets a target drive torque T for performing slip control for regulating the drive torque of the engine 11 based on the detection signal from the front wheel rotation sensor 66 and the detection signals from the rear wheel rotation sensors 80 and 81 at M4. Calculate _OS , and use M5 for rear wheel rotation sensor 8
The target drive torque T _OC of the engine 11 when the turning control for restricting the drive torque of the engine 11 is performed based on the detection signal from 0, 81 and the detection signal from the steering angle sensor 84 is calculated.

Then, at M6, the TCL76 determines these target driving torques T _OS , T
_An optimal final target drive torque T _O is selected from _OC by a method described later mainly considering safety. Furthermore, when the vehicle suddenly starts or when the road surface condition suddenly changes from a normal dry road to a frozen road, the output of the engine 11 may not be reduced in time even by the full closing operation of the throttle valve 20 via the actuator 41. , M7, the change rate G _s of the slip amount s of the front wheels 64, 65
Basic retard amount p correction select retard rate for performing the _B, these final target driving torque T _O and basic retardation amount p _B based on
The M8 outputs data on the retardation ratio to the ECU 15 at M8.

If the driver wants slip control or turning control by operating a manual switch (not shown), the ECU 15
As the driving torque of the engine 11 becomes the final target driving torque T _O, and controls the duty ratio of the pair of torque control solenoid valve 51 and 56, further data about the retard ratio of basic retard amount p _B Based on the calculated target retardation amount p ₀ in the ECU 15,
If necessary, the ignition timing P is delayed by the target retardation amount p _O , so that the vehicle 82 can travel without difficulty and safely.

If the driver does not want to perform slip control or turning control by operating a manual switch (not shown), the ECU 1
5 is the duty ratio 0 of the pair of torque control solenoid valves 51 and 56.
As a result of setting to the% side, the vehicle 82
The normal operation state corresponding to the depression amount of 31 is entered.

In this way, the drive torque of the engine 11 is controlled at M9 until the countdown every 15 milliseconds, which is the sampling period of the main timer, is completed, and thereafter, the steps from M2 to M10 are turned off by the ignition key switch 75. Sometimes it repeats until it becomes a state.

By the way, turning control is performed in the step of M5 and the engine 11
When the target drive torque T _OC is calculated, the TCL 76 calculates the vehicle speed V by the following equation (1) based on the detection signals of the pair of rear wheel rotation sensors 80 and 81, and also based on the detection signal from the steering angle sensor 84. The steering angle δ of the front wheels 64 and 65 is calculated by the following equation (2), and the target lateral acceleration G _YO of the vehicle 82 at this time is calculated by the following equation (3).
I want more respectively.

Here, V _RL and V _RR are the peripheral velocities of a pair of left and right rear wheels 78 and 79 (hereinafter referred to as rear wheel speeds), ρ _H is the steering gear speed ratio, and δ _H is the turning angle of the steering shaft 83. , L is the wheelbase of the vehicle 82, and A is the stability factor of the vehicle 82 described later.

The (3) As apparent from the equation, the aged deterioration such as wear of the steering gear which is not shown or when performing toe adjustment of the front wheels 64 and 65 at the time of maintenance of the vehicle 82, the neutral position [delta] _M of the steering shaft 83 If it changes, the turning position δ _{m of the} steering shaft 83
A deviation occurs between the actual steering angle δ of the front wheels 64 and 65 as the steered wheels. As a result, there is a possibility that the target lateral acceleration G _YO of the vehicle 82 may not be able to be accurately calculated, and it may be difficult to perform good turning control. Moreover, in this embodiment,
When slip control in M4 step, cornering drag correction means described later, from such that by correcting the reference driving torque of the period 11 based on the turning angle [delta] _H of the steering shaft 83, also slip control satisfactorily It may not be possible to do so. For this reason, it is necessary to learn correct neutral position [delta] _H of the steering shaft 83 at M3 steps.

The neutral position [delta] _M of the steering shaft 83 as shown in FIG. 5 showing a procedure for learning correction, TCL76 determines whether turning control flag F _C is set at H1. When it is determined that the vehicle 82 is turning control is determined in step H1, changes suddenly by the output of the engine 11 learns correct neutral position [delta] _M of the steering shaft 83, thereby deteriorating the riding comfort since there is a fear such, does not perform the neutral position [delta] _M of the learning correction of the steering shaft 83. On the other hand, when it is determined in step H1 that the vehicle 82 is not under the turning control, the neutral position δ of the steering shaft 83 is determined.
There is no problem even if the learning correction of _M is performed.
Based on the detection signal from the rear wheel rotation sensor 80, 81 is calculated by the vehicle speed V (1) Equation for learning and turning control to be described later in the neutral position [delta] _M in H2. Next, TCL76 is H3
After calculating the difference between the efficiency speeds V _RL and V _RR (hereinafter referred to as a rear wheel speed difference) | V _RL −V _RR |, the TCL 76 is driven by the steering shaft reference position sensor 86 at H4. in a state where the reference position [delta] _N has been detected in 83 whether the learning correction of the neutral position [delta] _M has been performed, i.e. the steering angle neutral position learned flag F in a state where the reference position [delta] _N of the steering shaft 83 is detected Determine whether _HN is set or negative. The steering shaft reference position sensor 86 functions as a steering angle reference position sensor that detects a neutral reference position of the steering angle.

Immediately after the ignition key switch 75 is turned on, the steering angle neutral position learned flag F _HN is not set, that is, learning of the neutral position δ _M is the first time, so the steering shaft turning position δ calculated this time at H5 is calculated. _It is determined whether or not _{m (n)} is equal to the steering shaft turning position Δm _(n−1) calculated last time. On this occasion,
It is desirable to set the rotation detection resolution of the steering shaft 83 by the steering angle sensor 84 to, for example, about 5 degrees so as not to be affected by the shake of the driver or the like.

If it is determined in step H5 that the currently calculated steering shaft turning position δm _(n) is _equal to the previously calculated steering shaft turning position δm _(n-1) , the vehicle speed V is reduced in H6. Preset threshold V _A
It is determined whether it is greater than. This operation is performed so that the vehicle 82 does not reach a certain high speed, and the rear wheel speed difference | V _RL −
This threshold is necessary because V _RR | cannot be detected, and the threshold value _VA is appropriately set to, for example, 10 km / h by an experiment or the like based on the traveling characteristics of the vehicle 82 and the like.

When it is determined that the vehicle speed V is greater than or equal to the threshold V _A at H6 step, TCL76 rear wheel speed difference at H7 | V _RL -V _RR
| Determined previously set, or smaller or not than such threshold value V _X of example hourly 0.3km, i.e. whether the vehicle 82 is running straight. Here, not to the threshold V _X and hourly 0km is,
If the tire pressure of the left and right rear wheels 78, 79 is not equal,
Although the vehicle 82 is in the straight traveling state, the peripheral speeds V _RL , V _{RR of the} pair of left and right rear wheels 78, 79 are different, so that it is possible to determine that the vehicle 82 is not in the straight traveling state. is there.

In the case the tire pressure of the right and left rear wheels 78 and 79 are not equal, the rear wheel velocity | V _RL -V _RR | so has a greater tendency in proportion to the vehicle speed V, and the threshold value V _X for example the 6 leave mapped variable as shown, it may be read threshold V _X based on the vehicle speed V from the map.

V _RL -V _RR | | rear wheel speed difference at this H7 step if is equal to or less than the threshold value V _X, the steering shaft reference position sensor 86 detects the reference position [delta] _N of the steering shaft 83 at H8 It is determined whether or not. Then, the steering shaft reference position sensor 86 has detected the reference position [delta] _N of the steering shaft 83 is determined in step H8,
That is, when it is determined that the vehicle 82 is in the straight traveling state, the count of the first learning timer (not shown) built in the TCL 76 is started at H9.

Next, the TCL 76 determines in H10 whether or not 0.5 seconds have elapsed from the start of counting of the first learning timer, that is, whether or not the straight traveling state of the vehicle 82 has continued for 0.5 seconds. If 0.5 seconds have not elapsed from the start of counting by the timer, it is determined at H11 whether the vehicle speed V is greater than the threshold value _VA . When it is determined in step H11 that the vehicle speed V is greater than the threshold value _VA , the rear wheel speed difference | V _RL −V _RR is determined in H12.
| Is equal to or less than such threshold value V _B hourly 0.1km. Rear wheel speed difference at this H12 step | V _RL -V _RR | is equal to or less than the threshold value V _B, i.e. if it is determined that the vehicle 82 is running straight, not shown, incorporated in the TCL76 at H13 The second learning timer starts counting.

Then, at H14, it is determined whether or not 5 seconds have elapsed from the start of counting of the second learning timer, that is, whether or not the straight traveling state of the vehicle 82 has continued for 5 seconds. If 5 seconds have not passed since
Then, the operation from the step H2 to the step H14 is repeated.

It determines that the steering shaft reference position sensor 86 at the middle the H8 step in the iteration is the reference position [delta] _N detection of the steering shaft 83, to start the first learning timer count at H9 in step At H10, 0.5 seconds have elapsed from the start of counting of the first learning timer, that is, the straight traveling state of the vehicle 82 is 0.5
If it is determined that s continued sets the steering angle neutral position learned flag F _HN in a state where the reference position [delta] _N of the steering shaft 83 is detected by H15, further criteria of the steering shaft 83 at H16 Position δ
_N determines whether the steering angle neutral position learning flag F _H in a state that is not detected is set. If it is determined in step H14 that 5 seconds have elapsed since the start of the counting of the second learning timer, the process shifts to step H16.

In the above operation, yet since the steering angle neutral position learned flag F _H in a state where the reference position [delta] _N of the steering shaft 83 is not detected is not set, the reference position [delta] _N of the steering shaft 83 in steps of this H16 is steering angle neutral position learned flag F _H is not set in a state that is not detected, i.e., learning of the neutral position [delta] _M in a state where the reference position [delta] _N of the steering shaft 83 is detected is determined to be the first time, Current steering axis turning position δ at H17
considers _m neutral position of the _(n) new steering shaft 83 [delta] _{M (n),} the steering angle neutral position learned in a state where the reference position [delta] _N of the steering shaft 83 is not detected with loading it into memory in the TCL76 to set the flag F _H.

In this way, after setting a new neutral position δ _{M (n)} of the steering shaft 83, while pivoting angle [delta] _H calculated steering shaft 83 to the neutral position [delta] _M of the steering shaft 83 as a reference, learning H18 The count of the use timer is cleared, and the steering angle neutral position learning is performed again.

The steering shaft turning position δm _(n) calculated this time in the step of H5 is the steering shaft turning position δm _(n-1) calculated last time.
Or if the vehicle speed V is not equal to or greater than the threshold value V _{A in} step H11, that is, if the rear wheel speed difference | V _RL −V _RR | calculated in step H12 is not reliable. If it is determined, or the rear wheel differential velocity determined in step H12 | V _RL -V _RR | if has a value greater than the threshold value V _B are both vehicle
Since 82 is not in the straight traveling state, the flow shifts to the step of H18.

In the step H7, the rear wheel speed difference | V _RL −V _RR |
And when it is determined to be greater than V _X, if the steering shaft reference position sensor 86 is determined not to detect the reference position [delta] _N of the steering shaft 83 in H8 step, the first learning at H19 and clears the count of the use timer, the process proceeds to step of the 11, wherein even when the vehicle speed V is equal to or less than the threshold value V _a at H6 step, can not be determined that the vehicle 82 is running straight Then, the process shifts to step H11.

On the other hand, in the step H4, the reference position δ _{N of the} steering shaft 83 is set.
When the steering angle neutral position learned flag F _HN in the state where the neutral position is detected is set, that is, when it is determined that the learning of the neutral position δ _M is the second or later, the steering shaft reference position sensor is set at H20. 86 determines whether or not to detect the reference position [delta] _N of the steering shaft 83. When the steering shaft reference position sensor 86 is determined in step H20 is determined to detect the reference position [delta] _N of the steering shaft 83 is greater than the threshold value V _A vehicle speed V is set in advance at H21 Determine whether or not.

If the vehicle speed V is equal to or greater than the threshold value V _A is at this H21 step, the rear wheel speed TC76 is at H22 | V _RL -V _RR |
It determines but whether the smaller than the threshold value V _X, i.e. whether the vehicle 82 is running straight. Then, the rear wheel speed is determined in step H22 | V _RL -V _RR | If it is determined that less than the threshold value V _X, the calculated steering shaft turning position δ _{m (n)} is calculated last time at H23 It is determined whether it is equal to the steering axis turning position Δm _(n-1) . If it is determined in step H23 that the currently calculated steering shaft turning position δm _(n) is _equal to the previously calculated steering shaft turning position δm _(n-1) , the first processing is performed in H24. The learning timer starts counting.

Next, the TCL 76 determines in H25 whether or not 0.5 seconds have elapsed from the start of counting of the first learning timer, that is, whether or not the straight traveling state of the vehicle 82 has continued for 0.5 seconds. If 0.5 seconds have not elapsed from the start of counting, the process returns to the step H2 and repeats the steps H2 to H4 and H20 to H25. Conversely, if it is determined in step H25 that 0.5 seconds have elapsed from the start of the count of the first learning timer, the process proceeds to step H16.

In step H20, the steering shaft reference position sensor 8
6 or when it is determined that want to detect the reference position [delta] _N of the steering shaft 83, the vehicle speed V is not the threshold V _A or in step H21, i.e. wheel speed difference after being calculated in H22 step | V _RL
-V _RR | when it is determined that there is no reliable, or the rear wheel speed difference at H22 step | V _RL -V _RR | and if has a value greater than the threshold value V _X, this step of H23 The calculated steering shaft turning position δ _{m (n)} is the previously calculated steering shaft turning position δ.
If it is determined that _m is not equal to _(n-1) , any of the above
Move on to step H18.

In step H16, the steering angle neutral position learned flag F _H
Is set, that is, when it is determined that the learning of the neutral position δ _M is the second or subsequent time, the TCL 76 sets the current steering shaft turning position δ _{m (n)} to the neutral position δ of the previous steering shaft 83 at H26.
It is determined whether it is equal to _{M (n-1)} , that is, δm _(n) = δM _(n-1) . Then, if it is determined that the current steering shaft turning position δm _(n) is _equal to the previous neutral position δM _(n-1) of the steering shaft 83, the process directly proceeds to step H18, and the next steering angle neutral is performed. Position learning is performed.

In step H26, the current steering shaft turning position δ _{m (n)}
When it is determined that the neutral position δM _{(n-1) of} the previous steering shaft 83 is not equal to the previous neutral position δM _(n-1) due to play of the steering system or the like, the present steering shaft turning position δm _(n) is New steering axis as it is
83 without determining the neutral position δ _{M (n)} of, when the absolute value is different preset correction limit amount Δδ above these differences, the previous steering shaft turning position δ _{m (n-1)} A value obtained by subtracting or adding the correction limit amount Δδ is used as a new neutral position ΔM _{(n) of the} steering shaft 83, and the neutral position ΔM _(n) is read into a memory in the TCL 76.

In other words, TCL76 is the current steering axis turning position δm _(n) at H27.
It is determined whether or not the value obtained by subtracting the previous neutral position ΔM _(n−1) of the steering shaft 83 is smaller than a preset negative correction limit amount −Δδ. Then, when it is determined that the value subtracted in the step of H27 is smaller than the negative correction limit amount -Δδ, the neutral position δM _(n) of the new steering shaft 83 is set to the previous steering angle in H28. Neutral position δ _{M (n-1) of} axis 83 and negative correction limit −Δ
From δ, it is changed to δM _(n) = δM _(n-1) -Δδ, so that the amount of learning correction per time is not unconditionally increased to the negative side. Accordingly, even if the detection signal or from the steering angle sensor 84 for some reason has been output, it is rapidly neutral position [delta] _M of the steering shaft 83 is not changed, it is possible to cope with this more quickly.

On the other hand, when it is determined that the value subtracted in the step of H27 is larger than the negative correction limit amount −Δδ, the current steering axis turning position δm _(n) is calculated from the current steering axis turning position δm _(n) in H29. It is determined whether the value obtained by subtracting the neutral position ΔM _(n−1) is larger than the correction control amount Δδ. Then, when it is determined that the value subtracted in the step of H29 is larger than the positive correction limit amount Δδ, the neutral position δ _{M (n)} of the new steering shaft 83 is changed to the previous steering shaft 83 in H30. Neutral position δ _{M (n-1)} and positive correction limit Δ
From δ, it is changed to δM _(n) = δM _(n-1) + Δδ, so that the amount of learning correction per time is not unconditionally increased to the positive side.

Thus, even an abnormal detection signal from the steering angle sensor 84 for some reason has been output, is rapidly neutral position [delta] _M of the steering shaft 83 is not changed, it is possible to cope with the abnormality quickly.

However, if it is determined that the value reduced in step H29 is smaller than the positive correction limit amount Δδ, the current steering shaft turning position δ _{m (n) is set} to the neutral position of the new steering shaft 83 in H31. δ
Read as it is as _{M (n)} .

Thus, when the present embodiment of learning correcting the neutral position [delta] _M of the steering shaft 83, the rear wheel speed difference | V _RL -V _RR | Besides using only the detection signals from the steering shaft reference position sensor 86 adopting a method of utilizing together, on the neutral position [delta] _M of the steering shaft 83 within the vehicle 82 is relatively fast since the start can be learned correction, failure steering shaft reference position sensor 86 for some reason rear wheel speed difference be | V _RL -V _RR | only at the neutral position of the steering shaft 83 [delta] _M
The learning can be corrected and the safety is excellent.

Therefore, when the stopped vehicle 82 starts with the front wheels 64 and 65 kept in the turning state, the neutral position δ of the steering shaft 83 at this time is started.
_As shown in FIG. 7 showing an example of a change state of _M , the steering shaft
When learning control neutral position [delta] _M of 83 for the first time, although the correction amount is very large from the initial value of the steering shaft pivoted position at step M1 of the aforementioned [delta] _{m (o),} the second and subsequent steering neutral position [delta] _M of the shaft 83, the operation in step H17, H19, the suppressed and state.

In this way, after the learning correction of the neutral position [delta] _M of the steering shaft 83, to regulate the driving torque of the engine 11 based on a detection signal from the detection signal and the rear wheel rotation sensor 80, 81 from the front wheel rotation sensor 66 Target drive torque for slip control
Calculate T _OS .

Incidentally, the coefficient of friction change rate of the vehicle speed V applied to the vehicle 82 of the tire and the road surface (hereinafter, referred to as longitudinal acceleration) can be regarded to be equivalent to G _X, the longitudinal acceleration in the present embodiment calculated based on the detection signal from the rear wheel rotation sensor 80, 81 a G _X, a reference driving torque T _B of the engine 11 corresponding to the maximum value of the longitudinal acceleration G _X, the front wheel is detected from the front wheel rotation sensor 66 fast V _F and the difference between the target wheel speed V _FO corresponding to the vehicle speed V (hereinafter, referred to as slippage) corrected based on s, it calculates the target driving torque T _OS.

As shown in FIG. 8 representing the operation block for calculating the target driving torque T _OS of the engine 11, first TCL76 is based on the vehicle speed V _S for slip control a detection signal of the rear wheel rotation sensor 80, 81 et al In this embodiment, the low vehicle speed selection unit
At 101, the smaller value of the two rear wheel speeds V _RL and V _RR is selected as the first vehicle speed V _S for slip control, and the high vehicle speed selector 10
Two rear wheel speed V _RL at 2, and select the second speed V _S of the larger for the value slip control of of the V _RR, on of the two selection units 101 and 102 via the selector switch 103 in its Which output is to be taken is further selected.

In this embodiment, the first vehicle speed V _S selected by the low vehicle speed selection unit 101 is calculated by the smaller value _VL of the two rear wheel speeds V _RL and V _{RR according to} the above equation (1). the coefficient K _V weighting corresponding to the vehicle speed V is multiplied by the multiplier section 104, which the two rear wheels speed V _RL, the larger value V _H of the _{V RR} (1-K V)
Is multiplied by the multiplication unit 105 and the result is added.

That is, the state where the driving torque of the engine 11 is actually reduced by the slip control, that is, the slip control flag F _S
Is set, the smaller value of the two rear wheel speeds V _RL and V _RR is selected as the vehicle speed V _S by the changeover switch 103, and even if the driving vehicle desires the slip control, the engine 11
State in which the drive torque of not reduced, in other words slip control flag F _S is reset state, the two rear wheel speed V
The larger one of _RL and V _RR is selected as the vehicle speed V _S.

This is because it is difficult to shift from a state in which the driving torque of the engine 11 is not reduced to a state in which the driving torque of the engine 11 is reduced, and it is also difficult to shift in the reverse case. For example, if you select wheel speed V _RL after two during turning of the vehicle 82, a smaller value of the V _RR as a vehicle speed V _S, slip despite slip the front wheels 64 and 65 does not occur Is determined to have occurred, and in order to avoid such a problem that the driving torque of the engine 11 is reduced, and in consideration of the traveling safety of the vehicle 82, the driving torque of the engine 11 is temporarily reduced. This is because consideration has been given to keep this state.

Further, when calculating the vehicle speed V _S at a low vehicle speed selection unit 101, and multiplied by a coefficient K _V weighting in the multiplication unit 104 to the smaller value V _L of the two rear wheels speeds V _RL, V _RR , This and two rear wheel speeds V
The larger value V _H of _RL and V _RR is multiplied by (1−K _V ).
Is added to the average value of the peripheral velocities of the front wheels 64 and 65 and the two rear wheel speeds V when traveling on a circuit with a small radius of curvature such as a left or right turn at an intersection or the like. _RL , V _RR
Is significantly different from the smaller value _{VL of}
This is because the amount of correction of the driving torque serving as feedback is too large, and the acceleration of the vehicle 82 may be impaired.

In the present embodiment, the weighting coefficient K _V is
Based on the vehicle speed V of the above equation (1), which is the average value of the peripheral velocities of 9, the data is read out from a map as shown in FIG.

Thus to calculate the longitudinal acceleration G _X based on the vehicle speed V _S for slip control, which is calculated on but first currently calculated vehicle speed V _{S (n)} and the vehicle speed calculated before once V _{S (n-1)} Accordingly, the current longitudinal acceleration GX _(n) of the vehicle 82 is calculated by the differential operation unit 106 as in the following equation.

Here, Δt is 15 milliseconds, which is the sampling period of this control, and g is the gravitational acceleration.

When the calculated longitudinal acceleration G _{X (n)} is 0.6 g or more, the maximum value of the longitudinal acceleration G _{X (n)} does not exceed 0.6 g in consideration of safety against the calculation mim. Then, the longitudinal acceleration GX _(n) is clipped by the clip unit 107 to 0.6 g. Further, a corrected longitudinal acceleration _GXF, which has been subjected to filter processing for noise removal in the filter unit 108, is calculated.

In this filtering process, since the longitudinal acceleration GX _(n) of the vehicle 82 can be considered to be equivalent to the friction coefficient between the tire and the road surface, the maximum value of the longitudinal acceleration GX _(n) of the vehicle 82 changes. Therefore, even when the slip rate S of the tire is likely to deviate from the target slip rate S ₀ corresponding to the maximum value of the coefficient of friction between the tire and the road surface or the vicinity thereof, the tire slip rate S
In order to maintain the tire and the road surface at a target slip ratio S ₀ corresponding to the maximum value of the coefficient of friction or a smaller value near the target slip ratio S ₀ , the longitudinal acceleration G _{X (n)} is corrected, Is performed as follows.

When the current longitudinal acceleration G _{X (n)} is _{equal to} or greater than the previous corrected longitudinal acceleration G _{XF (n-1)} , that is, when the vehicle 82 continues to accelerate, the current corrected longitudinal acceleration G _{XF (n )} Then, noise removal is performed by delay processing, and the corrected longitudinal acceleration G _{XF (n)} relatively quickly follows the longitudinal acceleration G _{X (n)} .

The current longitudinal acceleration G _{X (n)} is the previously corrected longitudinal acceleration G
When the value is less than _{XF (n-1)} , that is, when the vehicle 82 is not accelerating so much, the following processing is performed for each sampling period Δt of the main timer.

Slip control flag F _S is not set, in the state where that is not reducing the driving torque of the engine 11 by the slip control, since the vehicle 82 is in a deceleration _{G XF (n) = G XF} (n-1) As −0.002, a decrease in the corrected longitudinal acceleration G _{XF (n)} is suppressed, and responsiveness to the driver's request for acceleration of the vehicle 82 is ensured.

Further, even when the slip amount s is positive in a state where the driving torque of the engine 11 is reduced by the slip control, that is, when the front wheels 64 and 65 are slightly slipping, the vehicle 82 is decelerating. Since there is no problem, the reduction of the corrected longitudinal acceleration G _XF is suppressed by setting G _{XF (n)} = G _{XF (n−1)} −0.002, and responsiveness to the driver's request for acceleration of the vehicle 82 is secured.

Further, when the slip amount s of the front wheels 64 and 65 is negative while the driving torque of the engine 11 is subtracted by the slip control, that is, when the vehicle 82 is decelerating, the maximum value of the corrected longitudinal acceleration G _XF is held. Thus, responsiveness to the driver's request for acceleration of the vehicle 82 is ensured.

Similarly, during the shift-up of the hydraulic automatic transmission 13 by the hydraulic control device 16 in a state where the driving torque of the engine 11 is reduced by the slip control, it is necessary to secure a feeling of acceleration for the driver. Holds the maximum value of G _XF .

Then, the corrected longitudinal acceleration G _XF from which noise has been removed by the filter unit 108 is subjected to torque conversion by the torque conversion unit 109, and the value calculated by the torque conversion unit 109 is, of course, a positive value. since it should be a value, after clipping it to 0 or more for the purpose of preventing calculation errors by clip portion 110, and added by the adding unit 112 the running resistance T _R calculated by the running resistance calculating portion 111 Further, the cornering drag correction torque T _C calculated by the cornering drag correction amount calculation unit 113 based on the detection signal from the steering angle sensor 84 is added by the addition unit 114, and the reference driving shown in the following equation (4) is performed. to calculate the torque T _B.

_{T B = G FO · W b} , r + T R + T C ... (4) where, W _b is the body weight, r is an effective radius of the front wheel 64, 65.

The running resistance T _R is can be calculated as a function of the vehicle speed V, the in this embodiment are determined from the map as shown in Figure 10. In this case, the running resistance T _R between the flat road and the uphill road
Therefore, in the map, for the flat road shown by the solid line and for the uphill road shown by the two-dot chain line are written in the map, and based on the detection signal from the inclination sensor (not shown) incorporated in the vehicle 82, and so as to select either one, but it is also possible to set more finely running resistance T _R, including downhill and the like.

Further, in the present embodiment, the cornering drag correction torque T _C is obtained from a map as shown in FIG. 11, whereby a reference driving torque T _B of the engine 11 which is similar to the actual running state can be set. since the reference driving torque T _B of the turning immediately after the engine 11 is in the large acceleration feeling of the vehicle 82 after exiting the turning path is improved.

The reference driving torque calculated by the above equation (4)
In the present embodiment, the lower limit value is set by the variable clip unit 115 for T _{B, so} that a value obtained by subtracting a final correction torque T _PID described later from the reference drive torque T _B by the subtraction unit 116 is negative. This prevents problems that would otherwise occur. The lower limit of the reference driving torque T _B, as shown in the map as shown in FIG. 12, so that decrease stepwise in accordance with the time elapsed from the start of the slip control.

Meanwhile, TCL76 calculates the actual front wheel speed V _F on the basis of a detection signal from the front wheel rotation sensor 66, is set based on the vehicle speed V _S for the front wheel speed V _F and the slip control as previously described with a deviation between the target wheel speed V _FO correction torque calculation target front wheel speed V _FS is set based on the slip amount s, by performing feedback control of the reference driving torque T _B, the target driving of the engine 11 Calculate the torque T _OS .

By the way, in order to effectively use the driving torque generated by the engine 11 when the vehicle 82 is accelerating, as shown by the solid line in FIG.
However, the target slip ratio S ₀ corresponding to the maximum value of the coefficient of friction between the tire and the road surface or the target slip ratio S ₀ is adjusted so as to be a smaller value near the target slip ratio S ₀ , thereby avoiding energy loss and maneuvering performance and acceleration of the vehicle 82. It is desirable not to impair performance.

Here, the target slip ratio S ₀ is 0.1 according to the road surface condition.
It is known that the vehicle swings in the range of about 0.25. Therefore, it is desirable to generate the slip amount s of about 10% with respect to the road surface on the front wheels 64 and 65 as the driving wheels while the vehicle 82 is traveling. In consideration of the above points, the target front wheel speed _VFO is set by the multiplier 117 as shown in the following equation.

V _FO = 1 · 1 · V Then, the TCL 76 reads out the slip correction amount V _K corresponding to the above-mentioned corrected longitudinal acceleration G _XF from the map shown in FIG. To the target front wheel speed _VFO for calculating the reference torque. Although the slip correction amount V _K has a tendency to increase stepwise as the value of the corrected longitudinal acceleration G _XF increases, in the present embodiment, this map is created based on a running test or the like. I have.

Setting Accordingly, increasing the correction torque calculation target front wheel speed V _FS, so that the slip ratio S at the time of acceleration is smaller than this in the target slip ratio S ₀ or near shown by the solid line in FIG. 13 Is done.

On the other hand, the coefficient of friction between the tire and the road surface during turning,
As shown by a dashed line in FIG. 13, the relationship between the slip rate S of the timer and the tire slip rate at which the maximum value of the friction coefficient between the tire and the road surface during turning is determined by the tire and the road surface during straight running. It can be understood that the target slip ratio S _{O of the} tire, which is the maximum value of the friction coefficient of the tire, is considerably smaller. Therefore, it is desirable to set the target front wheel speed _VFO smaller than when traveling straight so that the vehicle 82 can turn smoothly while the vehicle 82 is turning.

Therefore, the turning correction unit 120 reads the slip correction amount V _KC corresponding to the target lateral acceleration G _YO from the map shown by the solid line in FIG. 15, and the subtraction unit 121 calculates the target front wheel speed V _FO for reference torque calculation. Subtract from However, until performed after the ON operation of the ignition key switch 75, since there is no reliable turning angle [delta] _H of the steering shaft 83, the peripheral velocity V _RL of the rear wheels 78 and 79, indeed by V _RR to the vehicle 82 Acting lateral acceleration G _Y
The slip correction amount V _KC is read from the map shown by the broken line in FIG.

By the way, the target lateral acceleration G _YO is calculated from the steering angle sensor 84 based on the detection signal from the steering angle sensor 84 according to the equation (2), and is calculated using the steering angle δ according to the equation (3). the neutral position δ _M of 83 are learning correction.

Therefore, the steering angle sensor 84 or the steering shaft reference position sensor 86
When the abnormality occurs, the target lateral acceleration G _YO may be a completely wrong value. Therefore, when an abnormality in the steering angle sensor 84 or the like occurs, the rear wheel speed difference | V _RL -V _RR | calculates the actual lateral acceleration G _Y generated on the vehicle 82 by using the target lateral acceleration this Use instead of G _YO .

Specifically, the actual lateral acceleration G _Y is the rear wheel speed difference | V _RL −
The corrected lateral acceleration G _YF is calculated from V _RR | and the vehicle speed V by the lateral acceleration calculator 122 incorporated in the TCL 76 as shown in the following equation (5), and this is subjected to noise removal processing by the filter 123. Can be

Here, b is the tread of the rear wheels 78 and 79, and the filter unit 123 calculates the current corrected lateral acceleration from the currently calculated lateral acceleration G _{Y (n)} and the previously calculated corrected lateral acceleration G _{YF (n-1).} G _{YF (n)}
Is subjected to low-pass processing by digital operation shown in the following equation.

Whether an abnormality has occurred in the steering angle sensor 84 or the steering shaft reference position sensor 86 can be detected by the TCL 76 by, for example, a disconnection detection circuit shown in FIG. In other words, the outputs of the steering angle sensor 84 and the steering shaft reference position sensor 86 are pulled up by the resistor R and grounded by the capacitor C, and the outputs are directly input to the A0 terminal of the TCL 76 for various controls. , A1 through comparator 88
Input to terminal. A specified value of 4.5 V is applied to the negative terminal of the comparator 88 as a reference voltage.
When the steering angle sensor 84 is disconnected, the input voltage of the A0 terminal exceeds a specified value, the comparator 88 is turned on, and the input voltage of the A1 terminal is continuously at the high level H. Therefore, if the input voltage of the A1 terminal is at a high level H for a certain period of time, for example, two seconds, the program of the TCL 76 is determined so that it is determined that a disconnection has occurred and the occurrence of an abnormality in the steering angle sensor 84 or the steering shaft reference position sensor 86 is detected. It has been set.

In the embodiment described above, the steering angle sensor is implemented by hardware.
Although an abnormality such as 84 is detected, it is of course possible to detect the abnormality by software.

For example, as shown in FIG. 17 showing an example of this abnormality detection procedure, the TCL 76 first determines an abnormality by the disconnection detection shown in FIG. 16 in W1, and when it is determined that the abnormality is not abnormal, Front wheel rotation sensor 66 and rear wheel rotation sensor 8 at W2
It is determined whether there is an abnormality in 0,81. If it is determined in step W2 that there is no abnormality in each of the rotation sensors 66, 80, and 81, the steering shaft 83 rotates one or more turns in the same direction in W3, for example.
It is determined whether the steering has been turned over 400 degrees. If it is determined in step W3 that the steering shaft 83 has been steered by 400 degrees or more in the same direction, the steering shaft
It determines whether there is a signal indicating the 83 reference position [delta] _N.

Then, in the step of W4, the reference position δ of the steering shaft 83 is set.
If it is determined that there is no signal indicating _N , if the steering shaft reference position sensor 86 is normal, the reference position δ of the steering shaft 83
Since there must be at least one signal indicating _N ,
At W4, it is determined that the steering angle sensor 84 is abnormal, and the abnormality occurrence flag _Fw is set.

If the steering shaft 83 at step W3 is determined not to be steered over 400 degrees in the same direction, or the signal indicating the reference position [delta] _N of the steering shaft 83 at W4 steps from the steering shaft reference position sensor 86 If it is determined that there is whether at least one of the neutral position δ or negative or learning _M is been finished, i.e. two steering angle neutral position learned flag F _HN, F _H is set at W6 Is determined.

In the step of W6, the neutral position δ _{M of the} steering shaft 83 is set.
If it is determined that learning has been completed, the rear wheel speed difference
| V _RL -V _RR | exceeds the example hourly 1.5 km, located between the vehicle speed V, for example, per hour 20km and hour 60km at W8, and absolute turning angle [delta] _H of the steering shaft 83 at this time at W9 value is, for example less than 10 degrees, i.e., when the vehicle 82 is determined to be turning at a certain speed, if the steering angle sensor 84 is functioning normally, the absolute value of the previous turning angle [delta] _H Should be 10 degrees or more, it is determined in W10 that the steering angle sensor 84 is abnormal.

Note that the slip correction amount V _KC corresponding to the target lateral acceleration G _YO may correspond to the corrected lateral acceleration G _YF in an area where the target lateral acceleration G _YO is small because the turning of the steering wheel 85 of the driving vehicle may be increased. Is set to be smaller than the slip correction amount V _KC to be applied. In the region where the vehicle speed V is low,
It is desirable to secure an acceleration of 82.
However, in the case of a certain speed abnormality, it is necessary to consider the ease of turning, so the slip correction amount V read from FIG.
_A correction coefficient corresponding to the _KC vehicle speed V is read from the map shown in FIG. 18 and multiplied to obtain a corrected slip correction amount V _KF.
Is calculated.

This will reduce the correction torque calculation target front wheel speed V _FO, becomes smaller than the target slip ratio S _O slip ratio S at the time of straight during a turn, although the acceleration performance of the vehicle 82 is slightly lowered, good pivot Nature is secured.

As shown in FIG. 19 showing the procedure for selecting the target lateral acceleration G _YO and the solid line lateral acceleration G _Y , the TCL 76 corrects from the filter unit 123 as the lateral acceleration for calculating the slip correction amount V _KC at T1. employing the lateral acceleration G _YF, it determines whether the slip control flag F _S is set at T2.

If the slip control flag F _S is determined in step T2 it is determined to have been set, the corrected lateral acceleration G _YF
Is adopted as it is. This is because when the lateral acceleration, which is a reference for determining the slip correction amount V _KC during the slip control, is changed from the corrected lateral acceleration G _YF to the target lateral acceleration G _YO , the slip correction amount V _KC greatly changes and the vehicle 82 This is because the behavior may be disturbed.

If step at the slip control flag F _S of the T2 is determined not to be set, the two steering angle neutral position learned F _HN at T3, or either one of the F _H is set Determine whether or not. Here, if it is determined that neither of the two steering angle neutral position learned flags F _HN and F _H has been set, the corrected lateral acceleration G _YF is employed as it is. If it is determined at step T3 that any of the two steering angle neutral position learned flags F _HN and F _H has been set, the slip correction amount V _KC is calculated at T4. The target lateral acceleration G _YO is adopted as the lateral acceleration of.

As a result, the target front wheel speed _VFS for calculating the correction torque is given by the following equation.

_{V FS = V FO + V K} -V F Next, the actual front wheel speed V _F obtained by the filter processing for the purpose of such as noise removal from the detection signal of the front wheel rotation sensor 66,
The subtraction unit 124 calculates a slip amount s, which is a deviation from the correction torque calculation target front wheel speed _VFS . When the slip amount s is equal to or less than a negative set value, for example, -2.5 km / h or less, the clip unit 125 clips the slip amount s of -2.5 km / h as the slip amount s. On the other hand, a proportional correction, which will be described later, is performed to prevent overcontrol in the proportional correction so that output hunting does not occur.

In addition, the slip amount s before the clipping process is subjected to integral correction using the integral constant ΔT _i described above, and a final correction torque T _{PID obtained} by further performing differential correction is calculated.

As the proportional correction, the slip amount s
Is multiplied by a comparison coefficient K _P to obtain a basic correction amount. Further, a multiplication unit 127 multiplies a correction coefficient ρ _KP preset by the speed ratio ρ _{m of the} hydraulic automatic transmission 13 to obtain a proportional correction torque T. _P
Have gained. Incidentally proportional coefficient K _P is as read from the map shown in FIG. 20 in accordance with the slip amount s after clipping.

In addition, in order to realize the integral correction and the correction corresponding to the gradual change of the slip amount s, a basic correction amount is calculated by the integration operation unit 128, and the correction amount is hydraulically operated by the multiplication unit 129. The integral correction torque T _I is obtained by multiplying a preset correction coefficient ρ _K1 based on the speed ratio ρ _m of the automatic transmission 13. In this case, in this embodiment, a constant smile integration correction torque ΔT _I is integrated, and when the slip amount s is positive every 15 ms sampling period, the small integration correction torque ΔT _I is added, and When the slip amount s is negative, the small integral correction torque ΔT _I is subtracted.

However, the integral correction torque T _I is set variable FIG. 21 map to show such a lower limit value T _IL in accordance with the vehicle speed V, the
At the start of the vehicle 82 by the clip processing, in particular during starting in climbing plate exerts a large integral correction torque T _I institutions 11
To ensure the driving force, from the vehicle speed V is increased after the start of the vehicle 82, since lack the stability of the control and reverse the correction is too large, so that smaller integral correction torque T _I. or,
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. 22.

The proportional correction torque T _P and the integral correction torque T _I calculated in this way are added by the adder 130 to calculate the proportional integral correction torque T _PI .

Note that the correction coefficients ρ _KP and ρ _KI correspond to the hydraulic automatic transmission 13
In association with the speed ratio [rho _m so that read from the map as shown in FIG. 23 which is set in advance.

Further, in this embodiment calculates a change rate G _s of the slip amount s by differentiating unit 131, which in multiplied by the differential coefficient K _D in multiplication unit 132, basic correction for sudden change in slip amount s Calculate the amount. And thereby a limit between the respective upper and lower limits to the value obtained, as differential correction torque T _D is not an extremely large value, performs a clip processing by the clip portion 133, differential correction torque T _D is getting. The clip portion 133 is connected to the wheel speeds V _F , V _RL , V
By the _RR is such a traveling state of the road surface conditions and vehicle 82, it may become momentarily idle or locked, will change ratio G _s of the slip amount s when such is a positive or negative extremely large value, since responsiveness control diverges may be deteriorated, for example, the lower limit is clipped to the upper limit value 55kgm with clips to -55Kgm, intended to prevent the differential correction torque T _D is not an extremely large value It is.

Accordingly then adds these proportional integration correction torque T _PI and differential correction torque T _D at the addition unit 134, subtracted from the aforementioned reference driving torque T _B at subtracting unit 116 the final correction torque T _PID thereby obtained Further, the multiplication unit 135 multiplies the reciprocal of the total reduction ratio between the engine 11 and the wheels 89 and 90 of the front wheels 64 and 65 to obtain the target drive torque T for slip control expressed by the following equation (6). Calculate the _OS .

Here, ρ _d is a differential gear reduction ratio, ρ _T is a torque converter ratio, and when the hydraulic automatic transmission 13 performs a shift operation of an upshift, the speed ratio ρ _m on the high speed side after the shift is completed. Is output. That is, when the shift operation of the up-shift hydraulic automatic transmission 13, when adopting a gear ratio [rho _m of the high-speed stage side output time point of the transmission signal,
As is apparent from the above equation (6), the target drive torque T _OS increases during the gear shift and the engine 11 blows up. Therefore, the shift operation is completed after the change start signal is output.
For example, 1.5 seconds, held gear ratio [rho _m of the low-speed stage side that can further reduce the target driving torque T _OS is the gear ratio [rho _m of the high-speed stage side is employed 1.5 seconds after the output signal of the shift start . For the same reason, when the shift operation of the down-shift hydraulic automatic transmission 13, the gear ratio [rho _m of the low-speed stage side output time of the transmission signal is action immediately.

Since the target drive torque T _OS calculated by the equation (6) should be a positive value as a matter of course, the clip portion
At 136, the target drive torque T _OS is clipped to 0 or more for the purpose of preventing a calculation error, and the target drive torque T _OS is determined according to the determination processing by the start / end determination unit 137 for determining the start or end of the slip control. Information about the _OS is output to the ECU 15.

Start and end determination unit 137 determines that the start of the slip control when satisfying all of the conditions shown in the following (a) ~ (e), from the low vehicle speed selection unit 101 with sets of slip control flag F _S output actuates the changeover switch 103 to select the vehicle speed V _S for slip control, and outputs information about the target driving torque T _OS to ECU 15, the slip control flag F _S to determine the end of the slip control This process is continued until reset.

(A) The driver operates a manual switch (not shown) to desire slip control.

(B) The driving torque _Td required by the driver is the minimum driving torque required for running the vehicle 82, for example, 4 kgm or more.

In the present embodiment, the required drive torque _Td is calculated based on the engine speed calculated from the detection signal from the crank angle sensor 62.
And N _E, the previously set based on the accelerator opening theta _A calculated by the detection signal from the accelerator opening sensor 76
It is read from a map as shown in FIG.

(C) The slip amount s is 2 km / h or more.

(D) The rate of change Gs of the slip amount _s is 0.2 g or more.

(E) the actual front wheel acceleration G _F obtained by differentiating the time with the actual front wheel speed V _F differentiating unit 138 is not less than 0.2 g.

On the other hand, after the start / end determining unit 137 determines the start of the slip control, if any of the following conditions (f) and (g) is satisfied, it is determined that the slip control has ended and the slip is determined. The control flag F _S is reset, the transmission of the target drive torque T _OS to the ECU 15 is stopped, and the switch 103 is operated so as to select the output from the high vehicle speed front end portion 102 as the vehicle speed V _S for slip control.

(F) The target drive torque T _OS is equal to or greater than the required drive torque T _d , and the state in which the slip amount s is equal to or less than a constant value, for example, −2 km / h, has continued for a certain time, for example, 0.5 seconds or more.

(G) The state in which the idle switch 68 has changed from off to on, that is, the state in which the driver has released the accelerator pedal 31, has continued for a certain period of time, for example, 0.5 seconds or more.

The vehicle 82 is provided with a manual switch (not shown) for the driver to select the slip control, and when the driver operates the manual switch to select the slip control, the driver performs the slip control described below. Perform the operation.

As shown in FIG. 25 illustrating a flow of processing of the slip control, TCL75 by various detection and processing as described above at S1, but calculates the target driving torque T _OS, this calculation operation of the manual switch It is performed independently of the operation.

Then, first, the slip control flag F _S at S2 is determines whether it is set, because the first slip control flag F _S is not set, TCL76 is in S3 front wheel 6
The slip amount s of 4,65 is a preset threshold value, for example, 2 k / h
It is determined whether it is larger than m.

Step by slip amount s of the S3 is determined to be larger than the hourly 2km, TCL76 determines whether the rate of change G _s of the slip amount s is greater than 0.2g at S4.

When the slip rate of change G _s at this step S4 is determined to be greater than 0.2 g, TCL76 minimum driving torque required for the requested driving torque T _d of the driver in S5 is to drive the vehicle 82, for example, It is determined whether or not it is larger than 4 kgm, that is, whether or not the driver intends to drive the vehicle 82.

Step in required driving torque T _d in the S5 is greater than 4Kgm, i.e. the driver determines that there is intention to drive the vehicle 82, sets in the slip control flag F _S at S6, the slip at S7 determining in the control whether the flag F _S is set again.

At this step S7 when the slip control flag F _S is determined to be in the set, for slip control in advance calculated by the equation (6) as the target driving torque T _OS of the engine 11 at S8 Adopt the target drive torque T _OS .

Further, when the step in the slip control flag F _S of the S7 is judged to have been reset, at S9 TCL76
Outputs the maximum torque of the engine 11 as the target driving torque T _OS, thereby ECU15 result of lowering the duty ratio of the torque control solenoid valve 51, 56 to 0% side, the engine 11 is of the accelerator pedal 31 by the driver A drive torque corresponding to the amount of depression is generated.

In the case when it is determined to be smaller than the slip amount s hourly 2km of the front wheels 64 and 65, that or the slip rate of change G _s in step S4 is determined to be smaller than 0.2g at step S3, or S5 Required drive torque _Td is 4k in step
If it is determined to be smaller than gm it is directly proceeds to step the S7, TCL76 at step S9 outputs a maximum torque of the engine 11 as the target driving torque T _OS, thereby electromagnetic for ECU15 torque control As a result of reducing the duty ratio of the valves 51 and 56 to the 0% side, the engine 11 generates a driving torque corresponding to the amount of depression of the accelerator pedal 31 by the driver.

On the other hand, in the step S2, the slip control flag F _S
If it is determined that is set, the front wheel 6
4,65 slip amount s is the hourly -2km less and the required driving torque T _d is a threshold value is less than the target driving torque T _OS calculated in S1 aforementioned state of determining whether or not to continue for 0.5 seconds or more I do.

Step by slip amount s is small and the requested driving torque T _d than 2km the target driving torque T _OS following hour state of S10 is continues for 0.5 seconds or more, i.e., the driver vehicle 82
Accelerating the already determined not to have desired to reset the slip control flag F _S at S11, the process proceeds to step S7.

In the step S10, the slip amount s is greater than 2 km / h, or the required drive torque _Td is equal to the target drive torque T
_When the state below the _OS does not continue for 0.5 seconds or more, that is, when the driver determines that the vehicle 82 is to be accelerated, the TCL 76
At 12, the idle switch 68 is turned on, that is, the throttle valve 20
It is determined whether the fully closed state has continued for 0.5 seconds or more.

If the idle switch 68 at this step S12 is determined to be ON, the driver since it is not depressing the accelerator pedal 31, the process proceeds to step S11 to reset the slip control flag F _S. Conversely, when it is determined that the idle switch 68 is off, the driver has depressed the accelerator pedal 31, and the process returns to step S7.

Incidentally, when the driver is not operating the manual switch to tip the slip control, TCL76 After calculating the target driving torque T _OS for the to slip control as described above, the engine 11 in the case of performing turning control Calculate the target drive torque.

Incidentally, the lateral acceleration G _Y of the vehicle 82 rear wheel speed difference | V _RL -V _RR |
Because it can actually be calculated by the equation (5) by utilizing, by utilizing the steering shaft turning angle [delta] _H, it is possible to predict the value of the lateral acceleration G _Y acting on the vehicle 82, This has the advantage that quick control can be performed.

Therefore, upon turning control of the vehicle 82, TCL76 from the steering shaft turning angle [delta] _H and the vehicle speed V, the target lateral acceleration G of the vehicle 82
_YO is calculated by the above equation (3), and an acceleration in the vehicle longitudinal direction such that the vehicle 82 does not undergo extreme understeering, that is, a target longitudinal acceleration G _XO is set based on the target lateral acceleration G _YO . Then, the target drive torque T _OC of the engine 11 corresponding to the target longitudinal acceleration G _XO is calculated.

As shown in FIG. 26 showing the calculation block of this turning control,
The TCL 76 calculates a vehicle speed V from the output of the pair of rear wheel rotation sensors 80 and 81 by the vehicle speed calculation unit 140 according to the above equation (1), and based on the detection signal from the steering angle sensor 84, the steering angle δ of the front wheels 64 and 65. Is calculated by the above equation (2), and a target lateral acceleration calculation unit is calculated.
At 141, the target lateral acceleration G _YO of the vehicle 82 at this time is described in (3) above.
It is calculated from the formula. In this case, when the vehicle speed V is low, for example, when the vehicle speed is 22.5 km or less, it is better to prohibit the turning control than to perform the turning control, for example, to obtain sufficient acceleration when turning left and right at an intersection with a large traffic volume. Therefore, in this embodiment, the target lateral acceleration G _YO is multiplied by the correction coefficient K _Y as shown in FIG. doing.

Incidentally, in the state where the learning of the steering shaft neutral position [delta] _M has not been performed, since it is calculated from the target lateral velocity G _YO (3) expression based on the steering angle [delta] is a problem in terms of reliability, steering until learning of the axial neutral position [delta] _M is performed, it is preferable not to start turning control. However, when the vehicle 82 travels on a curved road immediately after the start of traveling of the vehicle 82, the vehicle 82 requires turning control, but the steering shaft neutral position δ
_Since the learning start condition of _M is not easily satisfied, there is a possibility that a problem that this turning control is not started may occur. Therefore, until the present embodiment is performed the learning of steering shaft neutral position [delta] _M, the (5) using modified lateral acceleration G _YF from the filter unit 123 so as to perform the turning control based on the formula by the changeover switch 143 ing. That is, when both of the two steering angle neutral position learned flags F _HN and F _H are reset, the modified lateral acceleration G _YF is adopted by the changeover switch 143, and the two steering angle neutral position learned flags F _HN, if at least one of the F _H is set, the target lateral acceleration G _YO from the correction coefficient multiplication unit 142 via the selector switch 143
Is selected.

The stability factor A described above is a value determined by the configuration of the suspension system of the vehicle 82, the characteristics of the tires, the road surface condition, and the like, as is well known. Specifically, the actual lateral acceleration generated on the vehicle 82 at the time of steady circular turning G _Y and the neutral position [delta] _M of the steering angle ratio δ _H / δ _HO (steering shaft 83 of the steering shaft 83 at this time
For example the lateral acceleration G _Y represents the relationship between the ratio) of the turning angle [delta] _H of the steering shaft 83 during acceleration with respect to the pivot angle [delta] _HO of the steering shaft 83 in the extreme low speed running state becomes near zero relative to the first 28
It is expressed as the slope of a tangent in a graph as shown in the figure. That is, in the lateral acceleration G _Y is not very high vehicle speed V small area, but the stability factor A is almost constant value (A = 0.002), the lateral acceleration G _Y exceeds 0.6 g, stability Factor A increases sharply, causing vehicle 82 to exhibit a very strong tendency to understeer.

From the above, the dry pavement surface (hereinafter,
Based on FIG. 28 corresponding to the high μ road), the stability factor A is set to 0.002,
The target lateral acceleration G _{YO of the} vehicle 82 calculated by the equation (3) is
The drive torque of the engine 11 is controlled so as to be less than 0.6 g.

In the case of a slippery road surface such as a frozen road (hereinafter referred to as a low μ road), the stability factor A may be set to, for example, about 0.005. in this case,
On a low μ road, the target over-acceleration G _YO has a larger value than the actual lateral acceleration G _{Y. Therefore} , it is determined whether or not the target acceleration G _YO is larger than a preset threshold value, for example, (G _YF -2). If it is determined that the target lateral acceleration G _YO is larger than this threshold value, it is determined that the vehicle 82 is traveling on a low μ road, and the turning control for the low μ road may be performed as necessary. Specifically, the corrected lateral acceleration G _YF calculated based on the above equation (5) is 0.0
By adding 5 g, whether the target lateral acceleration G _YO is larger than the threshold value set in advance or not, that is, on the low μ road, the target lateral acceleration G _YO becomes larger than the actual lateral acceleration G _Y , so the target lateral acceleration G _YO becomes larger. It is determined whether or not the acceleration G _YO is greater than this threshold. If the target lateral acceleration G _YO is greater than the threshold, it is determined that the vehicle 82 is traveling on a low μ road.

When the target lateral acceleration G _YO is calculated in this way, if the target lateral acceleration G _YO is large, the target longitudinal acceleration G _XO of the vehicle 82 set according to the vehicle speed V in advance is calculated by the target longitudinal acceleration calculating unit 144. read from the map as shown in FIG. 29 previously stored in the TCL76, the reference drive torque calculating section 145 a reference driving torque T _B of the engine 11 corresponding to the target longitudinal acceleration G _XO
Is calculated by the following equation (7).

However, T _L is the lateral acceleration G _Y resistance of the road surface which is determined as a function of road load (Raod-Load) torque of the vehicle 82, in this embodiment, are calculated from the map as shown in FIG. 30.

Here, by the vehicle speed V steering shaft turning angle [delta] _H, engine
By simply calculating the target drive torque of 11, the intention of the driving vehicle is not reflected at all, and the driver may be dissatisfied with the maneuverability of the vehicle 82. For this reason, the engine 11
Seeking the requested driving torque T _d from the depression amount of the accelerator pedal 31, it is desirable to set the engine 11 target drive torque in consideration of the required driving torque T _d.

In order to determine the adoption ratio of reference driving torque T _B in the present embodiment obtains the corrected reference driving torque by multiplying the weighting coefficients α to the reference driving torque T _B in the multiplication section 146.
The weighting coefficient α is set empirically by turning the vehicle 82, and a numerical value of about 0.6 is adopted for a high μ road.

On the other hand, in the FIG. 29 the required driving torque T _d of the driver based on the accelerator opening theta _A detected wishes by the engine rotational speed N _E and an accelerator opening sensor 77 detected by the crank angle sensor 55 From the map as shown, then multiplying unit 14
In step 7, the correction required drive torque corresponding to the weighting coefficient α is calculated by multiplying the required drive torque _Td by (1−α). For example, if α = 0.6,
Adoption ratio of the reference driving torque T _B and the required driving torque T _d is 6
It becomes four.

Therefore, the target drive torque T _OC of the engine 11 is calculated by the addition unit 148 according to the following equation (8).

T _OC = α · T _B + (1−α) · T _d (8) By the way, if the increase or decrease of the target drive torque T _OC of the engine 11 set every 15 milliseconds is very large, the vehicle Since the shock accompanying the acceleration / deceleration of the 82 causes a decrease in ride comfort, if the increase or decrease in the target drive torque T _OC of the engine 11 becomes large enough to cause a decrease in the ride comfort of the vehicle 82, It is desirable to regulate the amount of increase or decrease of the target drive torque T _OC .

Therefore, in the present embodiment, the absolute value | ΔT | of the difference between the target drive torque T _{OC (n)} calculated this time and the target drive torque T _{OC (n−1)} calculated last time by the change amount clipping unit 149 is allowed to increase or decrease. If it is smaller than the capacity T _K , the calculated current target drive torque
Is adopted T _{OC (n) is} as it is, greater than the target driving torque T _{OC (n)} and the target driving torque T _{OC (n-1)} and the difference ΔT is negative decrease tolerance T _K previously calculated calculated this time If not, the current target drive torque T _{OC (n)} is set by the following equation.

T _{OC (n)} = T _{OC (n−1)} −T _{K In other} words, the reduction in the target drive torque T _{OC (n−1)} calculated last time is regulated by the permissible increase / decrease amount T _K and the drive torque of the engine 11 is recommended. Decrease the deceleration shock associated with In addition, the target drive torque T _{OC (n)} calculated this time and the target drive torque calculated last time are used.
If the difference ΔT from T _{OC (n−1)} is equal to or greater than the allowable increase / decrease amount T _K , the current target drive torque T _{OC (n)} is set by the following equation.

T _{OC (n) =} T _{OC (n−1)} + T _{K In other} words, the difference ΔT between the currently calculated target driving torque T _{OC (n)} and the previously calculated target driving torque T _{OC (n−1)} is an allowable increase / decrease amount.
If T _K is exceeded, the previously calculated target drive torque T
_The increase in _{OC (n-1)} is regulated by the allowable increase / decrease amount T _K , and
1. Reduce the acceleration shock associated with the increase in drive torque.

Then, information on the target drive torque T _OC is output to the ECU 15 according to the determination processing in the start / end determination section 150 for determining the start or end of the turning control.

The start / end determining unit 150 determines that the turning control is started when all of the following conditions (a) to (d) are satisfied,
Set the turning control flag F _C and set the target drive torque.
Information about T _OC output to ECU 15, the turning control flag F _C to determine the end of the turning control until the reset, and this process is continued.

(A) The target drive torque T _OC is less than a value obtained by subtracting a threshold value, for example, 2 kgm, from the required drive torque T _d .

(B) The driving vehicle operates a manual switch (not shown) to request turning control.

(C) The idle switch 68 is off.

(D) The control system for turning is normal.

On the other hand, after the start / end determining unit 150 determines the start of the turning control, if any of the following conditions (e) and (f) is satisfied, it is determined that the turning control has been completed and the turning is completed. reset the control flag F _C, to abort the target driving torque T _OC transmission to ECU 15.

(E) The target drive torque _TCS is _{equal to} or greater than the required drive torque _Td .

(F) The control system for turning has an abnormality such as failure or disconnection.

By the way, the output voltage of the accelerator opening sensor 77 and the accelerator opening θ _A naturally have a certain proportional relationship, and when the accelerator opening θ _A is fully closed, the accelerator opening sensor 77 The accelerator opening sensor 77 is attached to the throttle body 21 so that the output voltage becomes 0.6 volts, for example.
Is attached. However, when the accelerator opening sensor 77 is removed from the throttle body 21 for inspection and maintenance of the vehicle 82, and then reassembled, it is practically impossible to accurately return the accelerator opening sensor 77 to the original attached state. This is possible, and the position of the accelerator opening degree sensor 77 with respect to the throttle body 21 may be shifted due to aging or the like.

Therefore, in the present embodiment, the fully closed position of the accelerator opening sensor 77 is learned and corrected, and thereby the reliability of the accelerator opening θ _A calculated based on the detection signal from the accelerator opening sensor 77 is reduced. Is secured.

As shown in FIG. 31 showing a learning procedure of the fully closed position of the accelerator opening sensor 77, after the idle switch 68 is turned on and the ignition key switch 75 is turned off from the on state, a fixed time, for example, 2 seconds. The output of the ascel accelerator opening sensor 77 is monitored, and the accelerator opening sensor 77 during this time is monitored.
The minimum value of the output of the accelerator opening sensor 77 is taken in as a fully closed position of the accelerator opening θ _A and stored in a backup RAM (not shown) incorporated in the ECU 15 until the next learning. correcting the accelerator opening theta _a as a reference.

However, when the storage battery (not shown) mounted on the vehicle 82 is removed, the storage of the RAM is erased.
In such a case, the learning procedure shown in FIG. 32 is adopted.

That is, the TCL 76 is the fully closed value θ of the accelerator opening θ _A at A1.
It is determined whether or not _AC is stored in the RAM.
When it is determined that the fully closed value θ _AC of the accelerator opening θ _A is not stored in the RAM in the step of, the initial value θ is determined in A2.
_{A (O)} is stored in RAM.

On the other hand, if it is determined in step A1 that the fully closed value θ _AC of the accelerator opening θ _A is stored in the RAM, A3
It is determined whether or not the ignition key switch 75 is on. If it is determined in step A3 that the ignition key switch 75 has changed from the on state to the off state, the count of a learning timer (not shown) is started in A4. After the learning timer starts counting, it is determined at A5 whether or not the idle switch 68 is on.

If it is determined in step A5 that the idle switch 68 is in the OFF state, it is determined in A6 whether the count of the learning timer has reached a set value, for example, 2 seconds,
Return to step A5 again. If it is determined in step A5 that the idle switch 68 is ON, the output of the accelerator opening sensor 77 is read at a predetermined cycle in A7, and the current accelerator opening θ _{A (} A8) is read in A8. _n) determines whether less or not than the minimum value theta _AL accelerator opening theta _a far.

Here, when it is determined that the accelerator opening degree this time θ _{A (n)} is greater than the minimum value theta _AL accelerator opening theta _A to date, the minimum value theta _AL accelerator opening theta _A far If the current accelerator opening θ _{A (n)} is determined to be small, the current accelerator opening θ _{A (n)} is updated as a new minimum value θ _AL in A9. This operation is repeated in step A6 until the count of the learning timer reaches a set value, for example, 2 seconds.

If the learning timer count reaches the set value, A1
Clip value the minimum value theta _AL accelerator opening theta _A previously set at 0, it is determined whether there between for example 0.3 volts and 0.9 volts. Then, if the minimum value theta _AL of the accelerator opening theta _A is determined to be within the range of preset clip value, the initial value of the accelerator opening θ _A θ _{A (O)} or all at A11 A value obtained by bringing the value θ _AC closer to a constant value, for example, 0.1 volt, in the direction of the minimum value θ _AL is defined as a fully closed value θ _{AC (n)} of the accelerator opening θ _A by the current learning. That is,
If the initial value θ _{A (O)} or full closed value theta _AC of the accelerator opening theta _A is greater than its minimum value theta _{AL is, θ AC (n) = θ} A (O) -0.1 or, theta _{AC ( n)} = θ _{AC (n-1)} -0.1, and conversely, when the initial value θ _{A (O)} of the accelerator opening θ _A or the fully closed value θ _AC is larger than its minimum value θ _AL , Θ _{AC (n)} = θ _{A (o)} +0.1 or θ _{AC (n)} = θ _{AC (n-1)} +0.1

In step A10, the minimum value θ of the accelerator opening θ _A
If _{the AL} is determined to be out of the range of preset clip value replaces the clip value of those who are out at A12 as the minimum value theta _AL accelerator opening theta _A, the A1
All closed value theta _AC accelerator opening theta _A shifts to the first step
Learning correction.

Thus, by setting the upper limit value and the lower limit value to the minimum value theta _AL accelerator opening theta _A, an accelerator opening sensor
There is no danger that erroneous learning will be performed even if the 77 breaks down, and erroneous learning will not be performed even for disturbances such as noise by setting the learning correction amount per time to a constant value.

In the above-described embodiment, the learning start time of the fully closed value θ _AC of the accelerator opening sensor 77 is based on the time when the ignition key switch 75 changes from the on state to the off state.
Using a seating sensor incorporated in a seat (not shown), detecting that the driver has left the seat even when the ignition key switch 75 is on using a change in seat pressure or a change in position of the seat by the seating sensor, and the step of A4. The subsequent learning process may be started. When the door lock device (not shown) is operated from the outside of the vehicle 82 or the key entry system detects that the door lock device is operated, the fully closed value of the accelerator opening sensor 77 is detected. It is also possible to start learning of θ _AC . In addition, the position of the shift lever (not shown) of the hydraulic automatic speed change 13 is the neutral position or the parking position (neutral position in the case of a vehicle equipped with a manual transmission), the manual brake is operated, and The learning process may be performed when the air conditioner is in the off state, that is, not in the idle up state.

The vehicle 82 is provided with a manual switch (not shown) for the driver to select the turning control, and when the driver operates the manual switch to select the turning control, the turning control described below is performed. The operation is to be performed.

As shown in FIG. 33 showing the flow of the control for determining the target drive torque T _OC for the turning control, the target drive torque is obtained by detecting and calculating the various data described above at C1.
T _OC is calculated, but this operation is performed independently of the operation of the manual switch.

Next, it is judged whether or not the vehicle 82 at C2 is turning control, i.e. turning control flag F _C is set. Initially, not a turning control, the turning control flag F _C is determined to be reset, C3 example (T _d
-2) Judge whether it is below or not. That is, the target drive torque T _OC can be calculated even when the vehicle 82 is traveling straight, but the value is generally larger than the driver's required drive torque T _d . However, this required driving torque _Td is
When turning, the target driving torque
The time when T _OC becomes equal to or less than the threshold value (T _d −2) is determined as the start condition of the turning control.

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

In step C3, the target drive torque T _OC is set to the threshold (T _d −
2) If the following is determined, the TCL 76 determines at C4 whether the idle switch 68 is off.

Step at idle switch 68 is turned off in this C4, that is, when the accelerator pedal 31 is determined to have been depressed by the driver, the turning control flag F _C at C5 is set. Next, at C6, it is determined whether at least one of the two steering angle neutral position learned flags F _HN and F _H is set, that is, the reliability of the steering angle δ detected by the steering angle sensor 84 is determined. Is done.

In step C6, two steering angle neutral position learned flags F
_HN, when at least one of the F _H is determined to be set, whether the turning control flag F _C is set at C7 is determined again.

In the above procedure, the turning control flag is set in step C5.
Since F _C is set, it is determined that the turning control in-progress flag F _C is set in step C7, and the previous calculated value, that is, the target drive torque T _{OC in} step C1, is adopted as it is in C8. Is done.

On the other hand, if it is determined in step C6 that none of the steering angle neutral position learned flags F _HN and F _H has been set, it is determined whether the turning control flag F _C has been set in C17. Is determined again. If the turning control flag F _C is determined in step C17 it is determined to be set,
After step C8, since the steering angle δ calculated by the equation (2) is not reliable, the target driving torque of the equation (8) is calculated using the corrected lateral acceleration G _YF based on the equation (5). T _OC is this
It is adopted as the value calculated in the step of C8.

If it is determined in the step C17 that the turning control flag F _C has not been set, the target drive torque T _OC calculated by the equation (8) is not used, and the target drive torque T _OC is not used. As a result, the maximum torque of the engine 11 is output at C9, so that the ECU 15 reduces the duty ratio of the torque control solenoid valves 51 and 56 to the 0% side. As a result, the engine 11 reduces the amount of depression of the accelerator pedal 31 by the driver. Generates a corresponding drive torque.

If it is determined in step C3 that the target drive torque T _OC is not equal to or smaller than the threshold value (T _d −2), the flow proceeds from step C6 or C7 to step C9 without performing the turning control.
The TCL 76 outputs the maximum torque of the engine 11 as the target drive torque T _OC , whereby the ECU 15 reduces the duty ratio of the torque control solenoid valves 51 and 56 to the 0% side. A drive torque is generated in accordance with the amount of depression.

Similarly, when the idle switch 68 is turned on in step C4, that is, when it is determined that the accelerator pedal 31 is not depressed by the driver, the TCL 76 is also set to the target driving torque T.
The maximum torque of the engine 11 is output as _OC , and the ECU 1
5 reduces the duty ratio of the torque control solenoid valves 51 and 56 to the 0% side. As a result, the engine 11
The drive torque corresponding to the stepping amount of 31 is generated and the control does not shift to the turning control.

If it is determined in the step C2 that the turning control flag F _C is set, the target drive torque T _OC calculated this time and the target drive torque T
_{OC (n-1)} and the difference ΔT is equal to or greater than the increase or decrease the allowable amount T _K set in advance. This permissible increase / decrease amount T _K
It is a torque change amount that does not feel the acceleration / deceleration shock of 82, for example, the target longitudinal acceleration G _XO of the vehicle 82 is 0.1 g / sec.
If you want to reduce to Becomes

The target drive torque T calculated this time in step C10
When the difference ΔT between the _OC and the target driving torque T _OC previously calculated _(n-1) is not greater than the decrease tolerance T _k which is set in advance, in turn target drive torque T _OC and last at C11 The difference ΔT from the calculated target drive torque T _{OC (n-1)} is a negative increase / decrease allowable amount T _K.
It is determined whether it is greater than or equal to.

When the difference ΔT between the target driving torque calculated this time T _OC and the target driving torque T _OC previously calculated _(n-1) at C11 of step is determined to be larger than the negative decrease tolerance T _K, the target calculated this time Drive torque T _OC and target drive torque T calculated last time
Absolute value of the difference between the _{OC (n-1) | ΔT} | because less than decrease tolerance T _K, the target drive torque calculated in the C1 of step
T _OC is adopted as the value calculated in the step of C8.

Also, the target drive torque T calculated this time in the step of C11
When the difference ΔT between the _OC and the target driving torque T _OC previously calculated _(n-1) is not greater than the negative decrease tolerance T _K, C12
Then, the target drive torque T _OC this time is corrected by the following equation, and this is adopted as the value calculated in the step of C8.

T _OC = T _{OC (n−1)} −T _{K In other} words, the reduction in the target drive torque T _{OC (n−1)} calculated last time is regulated by the permissible increase / decrease amount T _K , and the deceleration accompanying the reduction of the drive torque of the engine 11 is performed. It reduces shock.

On the other hand, the difference Δ between the target drive torque T _OC calculated this time in the step of C10 and the target drive torque T _{OC (n−1)} calculated last time is shown in FIG.
If it is determined that T is greater than or equal to the permissible increase or decrease amount T _K , the target drive torque T _OC of this time is corrected in C13 according to the following equation, and is corrected by C8
Is adopted as the calculated value in the step.

T _OC = T _{OC (n−1)} + T _{K In other} words, in the case where the drive torque increases, the target drive torque T _OC calculated this time and the target drive torque T _{OC (} If _{the n-1)} difference between ΔT exceeds the decrease tolerance T _K restricts gains at decreasing tolerance T _K for the target driving torque T _OC previously calculated _(n-1), the driving of the engine 11 Acceleration shock accompanying an increase in torque is reduced.

When the target drive torque T _OC is set as described above, the TCL 76 determines in C14 whether the target drive torque T _OC is larger than the driver's required drive torque _Td .

Here, if the turning control flag F _C is set, the target drive torque T _OC is not larger than the driver's required drive torque T _d , so it is determined at C15 whether the idle switch 68 is on. I do.

If it is determined in step C15 that the idle switch 68 is not in the ON state, it is determined that the turning control is required, and the process proceeds to step C6. And
If it is determined in step C7 that the turning control flag F _C is set, or if it is determined in step C17 that the turning control flag F _C is set, C1 or C12
Alternatively, the calculated value adopted in the step C13 is selected as the target drive torque _TOC for turning control.

If it is determined in step C14 that the target drive torque T _OC is larger than the target person's required drive torque T _d , it means that the turning of the vehicle 82 has been completed.
Resets the turning control flag F _C at C16. Similarly, reset the idle switch 68 at C15 of step is determined to be ON state is, in the case where no accelerator pedal 31 is depressed, the swing control in Bragg F _C proceeds to step C16 I do.

When the turning control flag F _C is reset at C16, the TCL 76 outputs the maximum torque of the engine 11 at C9 as the target drive torque T _OC , whereby the ECU 15 sets the duty of the torque control solenoid valves 51 and 56. As a result of reducing the rate to the 0% side,
The engine 11 generates a driving torque according to the amount of depression of the accelerator pedal 31 by the driver.

It is naturally possible to ignore the driver's required driving torque _Td in order to simplify the above-described turning control procedure. In this case, the target driving torque can be calculated by the above-mentioned equation (7). it may be employed driving torque T _B.
Further, even when the driver's required driving torque _Td is taken into consideration as in the present embodiment, the weighting coefficient α is not set to a fixed value, but the coefficient α is gradually reduced with the lapse of time after the start of control. Alternatively, the rate of adoption of the driver's required driving torque _Td may be gradually increased in accordance with the vehicle speed V to gradually increase. Similarly, increased some time after start of control leave the value of the coefficient α to a constant value, or gradually decreased after a predetermined time period, or the value of the coefficient α with increasing steering shaft turning amount [delta] _H In particular, it is possible to make the vehicle 82 travel safely, especially in a circuit in which the radius of curvature becomes gradually smaller.

In the above-described embodiment, the target drive torque of the high μ road was calculated. However, the target drive torque of the turning control corresponding to the high μ road and the low μ road was calculated, and the target drive torque was calculated. The final target drive torque may be selected from the torque. In the above-described arithmetic processing method,
To prevent deceleration shock due to variations in the rapid driving torque of the engine 11, while working to regulation of the target driving torque T _OC by decreasing tolerance T _K on the occasion to calculate the target driving torque T _OC, this regulation _{May be} performed for the target longitudinal acceleration G _XO .

After calculating the target drive torque T _OC of the turning control, the TCL 76 selects an optimum final target drive torque T _O from these two target drive torques T _OS , T _OC and outputs this to the ECU 15. In this case, the target drive torque having a smaller numerical value is preferentially output in consideration of the traveling safety of the vehicle 82. However, since the target drive torque T _OS for slip control is generally always smaller than the target drive torque T _OC for turn control, the final target drive torque T _O for slip control and turn control must be selected in this order. Good.

As shown in FIG. 34 showing the flow of this processing, after calculating the target driving torque T _OC for turning control target driving torque T _OS for step control at M11, in the slip control by M12 flag F _S is determined whether it is set, if the slip control flag F _S is determined to have been set, the target driving torque T _OS for slip control as a final target drive torque T _O at M13 Select and output this to ECU15.

On the other hand, the slip control flag F
If it is determined that _S is not set, it is determined in M14 whether the turning control flag F _C is set, and if it is determined that the turning control flag F _C is set, The target drive torque T _OC for turning control is selected by the M15 as the final target drive torque T _O , and this is output to the ECU 15.

Further, if the turning control flag F _C determined in step M14 is determined not to be set, TCL76 is the maximum torque of the engine 11 as a final target drive torque T _O at M16 ECU 15
Output to

While the final target drive torque T _O is selected as described above, the output of the engine 11 cannot be reduced in time even when the throttle valve 20 is fully closed through the actuator 41, or the road surface condition changes from a normal dry road. when such a sudden change in frozen road, TCL76 sets the retard ratio basic retard amount p _B of the ignition timing P is set at ECU, and outputs it to the ECU 15.

The basic retard amount p _B is the maximum value of the retarded as not hindrance to operation of the engine 11 are set based on the intake air amount and the engine rotational speed N _E of the engine 11. Further, examples of retard rate, a zero level for the basic retard amount p _B 0 in the present embodiment,
And I level to compress the basic retard amount p _B two-thirds, basic and II level output as the retardation amount p _B, total closing operation of the throttle valve 20 while it outputs the base retardation amount p _B Do
Four is set with III level, basically according Benka rate G _s of the slip amount s is increased, and selecting the retard rate such that a significant amount of retardation.

As shown in FIG. 35 showing a procedure for reading the retard rate, whether TCL76 resets the flag F _P during the ignition timing control first in P1, slip control flag F _S is set at P2 Is determined. Judging step of the P2 and slip control flag F _S is set, P3
The ignition timing control flag _FP is set at, and it is determined at P4 whether the slip amount s is less than 0 km / h. In addition, a step in the slip control flag F _S of the P2 is determines that not set, the process proceeds to step of the P4.

If it is determined in step P4 that the slip amount s is less than 0 km / h, that is, it is determined that there is no problem even if the driving torque of the engine 11 is increased, the retard ratio is set to the 0 level in P5, and this is output to the ECU 15. I do. On the other hand, if it is determined in step P4 that the slip amount s is 0 km or more per hour,
If the slip rate of change G _s is equal to or less than 2.5g, steps in slip amount change rate G _s of the P6 is equal to or less than 2.5g in the late at P7 It is determined whether or not the angular ratio is at the III level.

Further, the slip rate of change G _s is determined in step P6 is 2.5g
Exceeds, i.e. when the front wheels 64 and 65 is determined to be slipping rapidly, the final target driving torque T _O at P8 4Kgm
It is determined whether or not the final target drive torque T _O
Is less than 4 kgm, that is, when it is determined that the driving torque of the engine 11 needs to be rapidly suppressed, the retardation ratio is set to the III level in P9, and the process proceeds to the step of P7.
Conversely, if it is determined in step P8 that the final target drive torque T _O is 4 kgm or more, the process directly proceeds to step P7.

If the retard rate for this P7 step is determined to be III level, it determines whether or not the slip amount change G _s exceeds 0g at P10. Here, the slip amount change rate G _s is greater than 0 g, i.e., when it is determined that there is a tendency to increase the slip amount s is whether the ignition timing control flag F _P set at P11 determining the slip rate of change G _s at P10 in step is less than 0 g, that is, when the slip amount s is determined to a decreasing tendency, beyond this slip amount s hourly 8km at P12 Is determined.

If it is determined in step P12 that the slip amount s exceeds 8 km / h, the process proceeds to step P11.If it is determined that the slip amount s is 8 km / h or less, the process proceeds to step P13. retard ratio Te a switch from III level to II levels, determines whether the slip rate of change G _s at P14 is less than 0.5 g. Similarly, when it is determined in the step P7 that the retardation ratio is not at the III level, this P14
Go to step.

Slip rate of change G _s in this P14 step is less than 0.5g, that is, when it is determined that the change in the slip amount s is not less abrupt, or negative retard the rate at P15 is II level It is determined whether or not. Further, the slip rate of change G _s at P14 steps when it is determined that it is not the less 0.5g sets the retard rate at P16 in II level, the processing proceeds to step P15.

If it is determined in step P15 that the retardation ratio is at the II level, the slip amount change rate G is determined in step P16.
_s is determined whether it exceeds 0 g, when the retard rate conversely is determined that it is not the II level determines whether the slip rate of change G _s is less than 0.3g at P17 . Slip rate of change G _s does not exceed the 0g determined in step P16,
That is, if it is determined that the slip amount s is decreasing, it is determined at P18 whether the slip amount s exceeds 8 km / h. If it is determined in step P18 that the slip amount s is equal to or less than 8 km / h,
Switch the retard ratio from II level to I level with
Move on to step 7. Further, the step at the slip rate of change G _s of P16 is not less than 0 g, that is, when the slip amount s is determined to be increasing, and the slip amount s at P18 step exceeds the hourly 8km That is, when it is determined that the slip amount s is large, the process shifts to the step P11.

The slip rate of change G _s in step P17 is less than 0.3 g, i.e. if the slip amount s is determined not almost increase, retarding the rate at P20 is whether the I level judge. Conversely, the slip rate of change G _s at P17 step exceeds the 0.3 g, that is, when the slip amount s is determined to more or less tends to increase, the retard rate at P21 I levels Set to.

When the retard rate is determined to be I level at P20 is the slip rate of change G _s at P22, it is determined whether or not beyond 0 g, which is less than 0 g, i.e. slippage If it is determined that s tends to decrease, it is determined in P23 whether the slip amount s is less than 5 km / h.
If it is determined in step P23 that the slip amount s is less than 5 km / h, that is, that the front wheels 64 and 65 are hardly slipping, the retard ratio is set to the 0 level in P24, and this is set to the ECU 15. Output. Further, it determines that or if the retard rate at P20 step has determined not to be I level, the slip amount change rate G _s exceeds the 0g at P22 step, namely slip amount s are increasing If it is determined that the slip amount s is equal to or greater than 5 km / h in step P23, that is, if it is determined that the slip amount s is relatively large, the process proceeds to step P11.

On the other hand, the ignition timing control flag F
If _P is determined to be set, the final target driving torque T _O at P25 is equal to or less than 10Kgm.
Further, when it is determined in step by the ignition timing control flag F _P of P11 is not set, the process proceeds to retard the rate at P26 after setting to zero level P25 step.

If the final target drive torque T _O is 10 kgm or more at P25, that is, if it is determined that the engine 11 is generating a slightly larger drive force, the retard angle ratio is at the II level at P27. It is determined whether or not this is the case. If it is determined that this retardation ratio is at the II level, the retardation ratio is reduced to the I level at P28, and this is output to the ECU 15.

Final target driving torque T _O is determined in step P25 is 10kgm
If it is determined that it is less than the predetermined value, or if it is determined in step P27 that the retard ratio is not at the II level, it is determined in step P29 whether the hydraulic automatic transmission 13 is shifting. If it is determined that the hydraulic automatic transmission 13 is shifting, it is determined in P30 whether or not the retardation ratio is at the III level. If it is determined that is, the retard ratio is reduced to the II level in P31, and this is output to the ECU 15. If it is determined in step P29 that the hydraulic automatic transmission 13 is not shifting,
Alternatively, if it is determined in step P30 that the retard ratio is not at the III level, the retard ratio previously set in P32 is output to the ECU 15 as it is.

For example, if the retarding proportion of III level is set at P9 step, slip amount s with the slip changing rate G _s is over 0g exceeds the hourly 8km, i.e. increasing the proportion of slip amount s is The final target drive torque T _O
If it is less than 10 kgm and the ignition timing is only retarded, the front wheels 64,
When it is determined that it is difficult to sufficiently suppress the slip of 65, the retardation ratio of the III level is selected, the opening of the throttle valve 20 is forcibly fully closed, and the occurrence of the slip is determined at the initial stage. We are trying to suppress it efficiently at the stage.

The ECU15 is retard amount as a preset ignition timing P and basic based on the intake air amount of the engine speed N _E and the engine 11
from a map (not shown) relating to p _B, read on the basis of these ignition timing P and basic retard amount p _B in the detection signal and the detection signal from the air flow sensor 70 from the crank angle sensor 62, retard This was sent from TCL76 It corrected based on the ratio, and to calculate the target retard amount p _0. In this case, the upper limit of the target retardation amount p _O is set in accordance with the upper limit temperature of the exhaust gas so as not to damage the exhaust gas purifying catalyst (not shown). It is detected by the detection signal.

If the cooling water temperature of the engine 11 detected by the water temperature sensor 71 is lower than a preset value, the ignition timing P
Since there is a risk that knocking or stall of the engine 11 may be caused by retarding the ignition timing, the following retarding operation of the ignition timing P is stopped.

As shown in FIG. 36 which represents the operation procedure of the target retard amount p _O in the retarded angle control, firstly ECU15 determines whether the slip control flag F _S described above in Q1 is set, this When the slip control flag F _S is determined to be set, it is determined whether the retard rate at Q2 is set to III level.

Then, the retard rate is determined in step Q2 that when it is determined that the III level, using base retardation amount p _B read out from the map at Q3 as it target retard amount p _O,
The ignition timing P is retarded by the target retardation amount p _O. Further, the duty ratio of the gastric solenoid valves 51 and 56 for torque control is set to 100% in Q4 so that the throttle valve 20 is fully closed irrespective of the value of the final target driving torque T _O , and is forcibly set. Throttle valve 2
A fully closed state of 0 is realized.

If it is determined in step Q2 that the retard ratio is not at the III level, it is determined at Q5 whether the retard ratio is set to the II level. If it is determined in the step of Q5 that the retardation ratio is at the II level, the basic retardation p _B obtained by reading the target retardation amount p _O from the map in Q6 in the same manner as in the step of Q3. Is used as the target retardation amount p _O as it is, and the ignition timing P is retarded by the target retardation amount p _O. Moreover, setting the duty ratio of the torque control solenoid valve 51, 56 at Q7 depending ECU15 the value of the target driving torque T _OS at Q7,
The driving torque of the engine 11 is reduced irrespective of the amount of depression of the accelerator pedal 31 by the driver.

Here the ECU 15 is stored a map for determining the throttle opening theta _T and a driving torque of the engine speed N _E and the engine 11 as parameters, ECU 15 the current engine speed N _E by using this map It reads the target throttle opening theta _tO corresponding to the and the target driving torque T _OS.

Next, the ECU 15 obtains a deviation between the target throttle opening θ _TO and the actual throttle opening θ _T output from the throttle opening sensor 67, and obtains a pair of torque control solenoid valves 51,5.
6 duty ratio of the electric current to the solenoid plunger 52, 57 of the set to a value commensurate with the deviation the torque control solenoid valve 51 and 56, the actual throttle opening by the operation of the actuator 41 theta _T is the target throttle Control is performed so as to lower the opening degree θ _TO .

When the maximum torque of the engine 11 is output to the ECU 15 as the target drive torque T _OS , the ECU 15 is a torque control solenoid valve.
The duty ratio is reduced to the 0% side of the duty ratios of 51 and 56, and a driving torque corresponding to the amount of depression of the accelerator pedal 31 by the driver is generated in the engine 11.

If it is determined in step Q5 that the retard ratio is not at the II level, it is determined at Q8 whether the retard ratio is set to the I level. If it is determined in the step of Q8 that the delay ratio is set to the I level,
The target retardation amount p _O is set as in the following equation, the ignition timing P is retarded by the target retardation amount p _{O, and the} process proceeds to step Q7.

On the other hand, if it is determined in step Q8 that the retardation ratio is not at the I level, it is determined whether the target retardation amount p _O is 0 in Q10, and it is determined that this is 0. If does not retard the ignition timing P proceeds to Q7 step, according to the value of the target driving torque T _OS torque control solenoid valve 51, 56
Set the duty ratio of the accelerator pedal by the driver
The drive torque of the engine 11 is reduced irrespective of the amount of depression of the 31.

If it is determined in step Q10 that the target retardation amount p _O is not 0, the target retardation amount p _O is increased by, for example, 1 degree by the ramp control in each sampling period Δt of the main timer in Q11. The subtraction is performed until p _O = 0, and the shock caused by the fluctuation of the driving torque of the engine 11 is reduced. Then, the process proceeds to step Q7.

In the step Q1, the slip control flag F _S
Is determined to have been reset, the normal driving control without reducing the driving torque of the engine 11 is performed, the ignition timing P is not retarded by setting p _O = 0 in Q12, and the torque control electromagnetic control is performed in Q13. By setting the duty ratios of the valves 51 and 56 to 0%, the engine 11 generates a driving torque according to the amount of depression of the accelerator pedal 31 by the driver.

<Advantage of the Invention> According to the vehicle steering angle neutral position learning method according to the present invention, the neutral position of the steering angle is determined by the vehicle speed (running speed), the wheel speed difference between the left and right wheels (rotation difference between left and right driven wheels), and the running time. The learning is automatically corrected even if there is a deviation between the steering angle and the actual steering angle due to toe-in adjustment or aging. As a result, driving force control and the like can be performed with high accuracy, and the stability of the physician is improved.

Further, even when the reference position cannot be detected by the steering angle reference position sensor (steering axis reference position sensor), the neutral position can be determined by the second neutral position determination means.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of one embodiment in which a vehicle output control device according to the present invention is applied to a front-wheel drive type vehicle incorporating a hydraulic automatic transmission of four forward steps and one reverse step, and FIG. FIG. 3, FIG. 3 is a sectional view showing the drive mechanism of the throttle valve, FIG. 4 is a flowchart showing the overall flow of the control, FIG. 5 is a flowchart showing the flow of neutral position learning correction of the steering shaft, and FIG. FIG. 7 is a map showing the relationship between the vehicle speed and the variable threshold value. FIG. 7 is a graph showing an example of a correction amount when the neutral position of the steering shaft is learned and corrected. FIG. 8 is a calculation procedure of a target drive torque for slip control. FIG. 9 is a map showing the relationship between the vehicle speed and the correction coefficient, FIG. 10 is a map showing the relationship between the vehicle speed and the running resistance, and FIG. 11 is a map showing the relationship between the steering shaft turning amount and the correction torque. Figure 12 shows the map immediately after the start of slip control. FIG. 13 is a graph showing a relationship between a coefficient of friction between a tire and a road surface and a slip ratio of the tire, and FIG. 14 is a graph showing a relationship between a target lateral acceleration and a speed correction accompanying acceleration. FIG. 15 is a map showing the relationship between the lateral acceleration and the speed correction amount accompanying turning, FIG. 16 is a circuit diagram for detecting an abnormality of the steering angle sensor, and FIG. 17 is a steering diagram. FIG. 18 is a flowchart showing the flow of the abnormality detection processing of the angle sensor 84, FIG. 18 is a map showing the relationship between the vehicle speed and the correction coefficient, FIG. 19 is a flowchart showing the flow of the lateral acceleration selection procedure, and FIG. FIG. 21 is a map showing the relationship between the vehicle speed and the lower limit value of the integrated correction torque, FIG. 22 is a graph showing the increase / decrease range of the integrated correction torque, and FIG. 23 is a hydraulic automatic transmission Compensation corresponding to each gear stage of the machine and each correction torque A map showing the relationship between the coefficient and the coefficient, FIG. 24 is a map showing the relationship between the engine speed, the required drive torque and the accelerator opening, FIG. 25 is a flowchart showing the flow of the slip control, and FIG. FIG. 27 is a block diagram showing a procedure for calculating a target drive torque, FIG. 27 is a map showing a relationship between a vehicle speed and a correction coefficient, and FIG.
FIG. 28 is a graph showing the relationship between the lateral acceleration and the steering angle ratio for explaining the stability factor, FIG. 29 is a map showing the relationship between the target lateral acceleration, the target longitudinal acceleration and the vehicle speed, and FIG.
FIG. 31 is a map showing the relationship between lateral acceleration and road load torque, FIG. 31 is a graph showing an example of a learning correction procedure of the fully closed position of the accelerator opening sensor, and FIG. 32 is a fully closed position of the accelerator opening sensor. Is a flowchart showing another example of the flow of the learning correction, FIG. 33 is a flowchart showing a flow of the turning control, FIG. 34 is a flowchart showing a flow of a selection operation of the final target torque, and FIG. 35 is a selection of the retardation ratio FIG. 36 is a flowchart showing a flow of operation, and FIG. 36 is a flowchart showing a procedure of engine output control. Also, reference numerals 11 in the figure indicate an engine, 13 indicates a hydraulic automatic transmission, 15
Is an ECU, 16 is a hydraulic control device, 20 is a throttle valve, 23 is an accelerator lever, 24 is a throttle lever, 31 is an accelerator pedal, 32 is a cable, 34 is a claw, 35 is a stopper, 41 is an actuator, and 43 is a control rod. , 47 is a connection pipe, 48 is a vacuum tank, 49 is a check valve, 50 and 55 are pipes, 51 and 56 are solenoid valves for torque control, 60 is a solenoid valve, 61 is a spark plug, 62 is a crank angle sensor, 64 , 65 is the front wheel, 66 is the front wheel rotation sensor, 6
7 is a throttle opening sensor, 68 is an idle switch, 70
Is an air flow sensor, 71 is a water temperature sensor, 74 is an exhaust temperature sensor, 75 is an ignition key switch, 76 is a TCL, 77 is an accelerator opening sensor, 78 and 79 are rear wheels, 80 and 81 are rear wheel rotation sensors, 82 is Vehicle, 83 is a steering shaft, 84 is a steering angle sensor, 85 is a steering wheel, 86 is a steering shaft reference position sensor, 87 is a communication cable, 104, 105, 117, 135 is a multiplier, 106, 131 is a differential calculator, 107, 110 is a clipper, and 108, 123 are filters. Department, 109
Is a torque conversion section, 111 is a running resistance calculation section, 112, 114, 119 are addition sections, 113 is a cornering drag correction amount calculation section, 115
The variable clip portion, 116,121,124 subtraction unit, 118 the acceleration correction unit, 120 is the turning correction unit, 122 is a lateral acceleration calculation unit, A is a stability factor, b is the tread, F _P is the ignition timing control flag, F _S slip control flag is, G _F is the actual front wheel acceleration, G _KC, G _KF front wheel acceleration correction quantity, G _s is the slip rate of change, G _XF is corrected longitudinal acceleration, G _XO is the target longitudinal acceleration, G _YO the target lateral acceleration, g is the gravitational acceleration, N _E is engine speed, P is the ignition timing, p _B is the basic retard amount, P _O is the target retard amount, r is the wheel effective radius, S _O is the target slip ratio, s is the slip amount, T _B is the reference drive torque, T _C is the cornering drag correction torque, T _D is the differential correction torque, T _d is the required drive torque, T _I is the integral correction torque, T _O is the final target drive torque, T T
_OC is the turning control target driving torque, T _OS is aimed driving torque for slip control, T _P is proportional correction torque, T _PID final correction torque, T _R is running resistance, Delta] t is the sampling period, V is the vehicle speed, V _F the actual front wheel speed, V _FO, V _FS is target front wheel speed, V _K, V _KC slip correction amount, V _RL is the rear left wheel speed, V _RR right rear wheel speed, V _S is the vehicle speed for slip control, W _b is the body weight, [delta] is a front wheel steering angle, [delta] _H is the turning angle of the steering shaft, [rho _d is operated gear reduction ratio, [rho
_KI is an integral correction coefficient, ρ _KP is a proportional correction coefficient, ρ _m is a gear ratio of the hydraulic automatic transmission, and ρ _T is a torque converter ratio.

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // B62D 101: 00 105: 00 111: 00 113: 00 (72) Inventor Masayuki Hashiguchi 5 Shiba, Minato-ku, Tokyo No. 33-8, Mitsubishi Motors Corporation (72) Inventor Miyajin Anshin 5-33-8, Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (56) References JP-A-61-11608 JP, A)

Claims (1)

(57) [Claims] A steering angle sensor for detecting a steering angle; a steering shaft reference position sensor attached to the steering wheel for detecting whether or not the turning position of the steering wheel is at a position corresponding to a straight traveling state of the vehicle. Running speed detecting means for detecting each wheel speed and the vehicle speed of the left and right wheels, wherein the steering shaft reference position sensor does not detect that the turning position of the steering wheel is at a position corresponding to the straight traveling state of the vehicle, When the vehicle speed is equal to or higher than the set vehicle speed and the wheel speed difference between the left and right wheels is equal to or lower than the set wheel speed difference for a first set time or more, the current steering angle detected by the steering angle sensor is set to the neutral position. The steering shaft reference position sensor detects that the turning position of the steering wheel is at a position corresponding to the straight traveling state of the vehicle, and the vehicle speed is equal to or higher than the set vehicle speed, and the wheel speeds of the left and right wheels are determined. When the state where the difference is equal to or less than the set wheel speed difference has continued for a second set time shorter than the first set time, it is determined that the current steering angle detected by the steering angle sensor is a neutral position. A method for learning a neutral position of a steering angle of a vehicle.