JP2518451B2 - Vehicle output control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application> The present invention relates to an output control device for a vehicle, and obtains a target lateral acceleration by using a steering angle with respect to a steering shaft neutral position that is determined by learning. It is useful when applied to the case where output control is performed when the vehicle turns.

<Prior Art> Since a centrifugal force corresponding to a lateral acceleration in a direction perpendicular to the running direction is generated in a vehicle running on a turning circuit, if the running speed of the vehicle with respect to the turning circuit is too high, a tire There is a risk that the vehicle body will skid beyond the limit of the grip force.

In such a case, in order to properly lower the output of the engine and safely drive the vehicle with a turning radius corresponding to the turning circuit,
Especially when the exit of the turning circuit cannot be confirmed, or when the radius of curvature of the turning circuit is gradually decreasing,
Extremely advanced driving technology is required.

In a general vehicle having a so-called understeering tendency, it is necessary to gradually increase the steering amount with an increase in the lateral acceleration applied to the vehicle. However, when the lateral acceleration exceeds a certain value specific to each vehicle, the steering becomes As described above, the fuel cell has such characteristics that it becomes difficult or impossible to make a safe turning operation as described above. It is well known that this tendency becomes remarkable especially in a front engine front-wheel drive type vehicle with a strong tendency to understeer.

For this reason, the lateral acceleration of the vehicle is detected and the engine output is forcibly reduced before the turning limit at which the vehicle becomes difficult or unable to turn, regardless of the accelerator pedal depression amount by the driver. An output control device designed to control the output of the engine is controlled according to the traveling (hereinafter referred to as a turning control mode) using the output control device and the accelerator pedal depression amount when necessary. It has been announced that it is possible to choose between normal driving and running.

As a type of output control of the vehicle based on such a viewpoint, the lateral acceleration of the vehicle is detected, regardless of the amount of depression of the accelerator pedal by the driver before the vehicle becomes difficult or impossible to turn, There is known an output control device that forcibly reduces the output of the engine in accordance with the magnitude of lateral acceleration.

That is, this type of output control device sets a target drive torque of the engine according to a lateral acceleration and a torque reducing means for reducing the drive torque of the engine independently of the operation by the driver, and the drive torque of the engine. And a turning control unit for controlling the operation of the torque reducing means so that the target driving torque is obtained.

As the lateral acceleration, the lateral acceleration that actually acts on the vehicle may be used, but in this case, there is a problem that a control delay occurs. Therefore, the value of the lateral acceleration is calculated by using the steering angle of the steering shaft. It has been proposed that the predicted lateral acceleration (hereinafter referred to as the target lateral acceleration) be used to perform control during turning based on the lateral acceleration.

On the other hand, in order to utilize the target lateral acceleration for turning control, the reliability of the steering angle detected by the steering angle sensor becomes a problem. That is, since the rudder angle sensor that detects the rudder angle is removed from the fixed portion such as the steering shaft when the vehicle is repaired, the output signal generally includes an offset amount due to a mounting error at the time of remounting. . Therefore, every time the ignition switch is turned on, it is detected by learning that the steering shaft has reached the neutral position, which is the reference position, and the target lateral acceleration is obtained using the steering angle with respect to this steering shaft neutral position, which is the reference position. Is proposed. At this time, it is the simplest to set the steering shaft neutral position to the position of the steering shaft in the rectilinear image body of the vehicle.

<Problems to be Solved by the Invention> As described above, when learning of the steering shaft neutral position is performed in a straight traveling state of the vehicle, it is feared that this learning cannot be practically performed. That is, when starting from the middle of a meandering mountain road, the vehicle cannot satisfy the predetermined straight traveling condition, and therefore, the learning of the steering shaft neutral position is not executed forever.

Therefore, the turning control executed based on the target lateral acceleration obtained by using the steering angle accompanied by the learning correction needs to be controllable, for example, when traveling on a meandering mountain road from this midway. Nevertheless, there is a problem that this turning control may not be performed in some cases.

In view of the above problems, it is an object of the present invention to provide an output control position of a vehicle that can perform turning control as needed even when learning of the steering shaft neutral position is not executed.

<Means for Solving the Problems> The configuration of the present invention that achieves the above-mentioned object is a torque reducing means capable of reducing the drive torque of the engine independently of the operation by the driver, and a lateral direction generated in the turning vehicle. A vehicle having a turning control unit that sets a target drive torque of the engine according to a lateral acceleration that is an acceleration and controls the operation of the torque reducing means so that the drive torque of the engine becomes the target drive torque. In the output control device, the straight traveling state of the vehicle is detected by learning, and the steering shaft in this straight traveling state is set as the steering shaft neutral position, and the target lateral acceleration is calculated based on the steering angle with respect to the steering shaft neutral position and the vehicle speed. Acceleration calculation means, lateral acceleration detection means for detecting the lateral acceleration that actually acts on the vehicle, and actual lateral acceleration until the steering neutral position of the vehicle is detected. Is selected as the lateral acceleration for the turning control unit to perform the turning control, while the amount based on the target lateral acceleration for the turning control unit to perform the turning control after the steering shaft neutral position is detected. And a switch unit for selecting the lateral acceleration.

Incidentally, as a torque reduction means for lowering the driving torque of the engine, it is general to delay the ignition timing, reduce the intake air amount or the fuel supply amount, or stop the fuel supply. For example, an engine having a reduced compression ratio may be employed.

<Operation> According to the present invention having the above configuration, when the steering axis neutral position learning correction is executed and reliable steering angle information is obtained, when the driver turns the steering wheel at a certain vehicle speed, the vehicle is The target lateral acceleration can be calculated based on the vehicle speed and the reliable steering angle at the same time when the steering wheel is turned, and the turning control is executed based on the target lateral acceleration. It Further, according to the configuration of the present invention, until the learning correction of the steering shaft neutral position is executed,
The turning control is executed based on the lateral acceleration that actually acts on the vehicle. Therefore, the turning control can be performed whenever necessary.

<Examples> Fig. 1 showing the concept of an example in which the vehicle output control device according to the present invention is applied to a front-wheel drive type vehicle incorporating an automatic transmission having four forward gears and one reverse gear and a schematic diagram of the vehicle. As shown in FIG. 2 showing the structure, an input shaft 14 of a hydraulic automatic transmission 13 is connected to an output shaft 12 of the engine 11. This hydraulic automatic transmission 13 is an electronic control unit (hereinafter referred to as an ECU) 15 that controls the operating state of the engine 11 according to the selection position of a select lever (not shown) by the driver and the operating state of the vehicle. On the basis of a command from, a predetermined gear stage is automatically selected via the hydraulic control device 16. The specific structure and operation of the hydraulic automatic transmission 13 are described in, for example, JP-A-58-54270 and JP-A-63-3.
As already known in Japanese Patent No. 1749, hydraulic control device 16
A pair of shift control solenoid valves (not shown) for performing engagement operation and disengagement operation of a plurality of friction engagement elements forming a part of the hydraulic automatic transmission 13 are incorporated therein. ECU15 for turning on / off the power to the solenoid valve
By performing the control in accordance with the above, the speed change operation to any gear position among the four forward gears and the one reverse gear can be 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 that adjusts the amount of intake air supplied into the combustion chamber 17 by changing the opening degree of an intake passage 19 formed by the intake pipe 18 is interposed. As shown in FIG. 1 and FIG. 3 showing the enlarged cross-sectional structure of this cylindrical throttle body 21,
On the throttle body 21, both ends of a throttle shaft 22 to which the throttle valve 20 is integrally fixed are rotatably supported. An accelerator lever 23 and a throttle lever 24 are coaxially fitted to one end of the throttle shaft 22 protruding 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, the washer 28 and the nut 29 attached to one end of the throttle shaft 22 prevent the accelerator lever 23 from coming off the throttle shaft 22. Also, the cable receiver 30 integrated with the accelerator lever 23
An accelerator pedal 31 that is operated by the driver is connected via a cable 32, and the accelerator lever 23 rotates with respect to the throttle shaft 22 in accordance with the amount of depression of the accelerator pedal 31. .

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
Rotate with. Further, a collar 33 is coaxially and integrally fitted to the tubular portion 25 of the accelerator lever 23, and the tip end portion of the throttle lever 24 is engaged with a claw portion 34 formed on a part of the collar 33. A stopper 35 that can be used is formed.
The claw portion 34 and the stopper 35 are locked to each other when the throttle lever 24 is rotated in the direction of opening the throttle valve 20 or the accelerator lever 23 is rotated in the direction of closing the throttle valve 20. It is set in a proper positional relationship.

Between the throttle body 21 and the throttle lever 24, a torsion coil spring 36 for pressing a stopper 35 of the throttle lever 24 against a claw portion 34 of a collar 33 integrated with the accelerator lever 23 to urge the throttle valve 20 in the opening direction. Is a pair of cylindrical spring receivers 37, 3 fitted to the throttle shaft 22.
It is mounted coaxially with the throttle shaft 22 via 8. The collar 33 is also provided between the stopper pin 39 protruding from the throttle body 21 and the accelerator lever 23.
The torsion coil spring 40 for pressing the claw portion 34 of the lever 34 against the stopper 35 of the throttle lever 24 to urge the throttle valve 20 in the closing direction to give a detent feeling to the accelerator pedal 31 is provided through the collar 33. It is mounted on the cylinder portion 25 of the lever 23 so as to be coaxial with the throttle shaft 22.

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

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.
The vacuum tank 48 communicates with each other through a check valve 49 that allows only the movement of air from the vacuum tank 48 to the surge tank 46 between the vacuum tank 48 and the connection pipe 7. There is. As a result, the pressure in the vacuum tank 48 is set to a negative pressure substantially equal to the minimum pressure in the surge tank 46.

Inside 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 has a plunger 52 so as to close the pipe 50.
A spring 54 for urging the valve seat 53 against the valve seat 53 is incorporated.

A pipe 55 connecting to the first torque control solenoid valve 51 and the actuator 41 is connected to a pipe 55 communicating with the intake passage 19 on the upstream side of the throttle valve 20. A second solenoid valve 56 for torque control that is open when not conducting is provided in the middle of the pipe 55. That is, the torque control solenoid valve 56 incorporates the spring 58 that biases the plunger 57 so as to open the pipe 55.

The two torque control solenoid valves 51, 56 include the ECU 15
Are connected to each other, and on / off of energization of the torque control solenoid valves 51, 56 is duty controlled based on a command from the ECU 15. In the present embodiment, the torque reduction of the present invention is achieved as a whole. Constitutes a means.

For example, when the duty ratio of the torque control solenoid valves 51, 56 is 0%, the pressure chamber 44 of the actuator 41 becomes an atmospheric pressure substantially equal to the pressure in the intake passage 19 upstream of the throttle valve 20, and the throttle valve 20 Is the accelerator pedal 31
One-to-one correspondence with the depression amount of. On the contrary, when the duty ratio of the torque control solenoid valves 51, 56 is 100%, the pressure chamber 44 of the actuator 41 becomes a negative pressure almost equal to the pressure in the vacuum tank 48, and the control rod 43 is left in FIG. As a result of being lifted diagonally upward, the throttle valve 20 becomes an accelerator pedal.
It is closed regardless of the depression amount of 31, and the driving torque of the engine 11 is forcibly reduced. In this way, by adjusting the duty ratio of the torque control solenoid valves 51, 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.

Further, in the present 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 used as an accelerator. It is also possible to connect only the pedal 31 and the other throttle valve only to the actuator 41, and control these two throttle valves independently.

On the other hand, the combustion chamber of the engine 11 is provided on the downstream end side of the intake pipe 18.
Fuel injection nozzles 59 of a fuel injection device for injecting fuel (not shown) into 17 are provided respectively corresponding to 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 via a controlled solenoid valve 60. That is, by controlling the valve opening time of the solenoid valve 60, the amount of fuel supplied to the combustion chamber 17 is adjusted, and the combustion chamber 17 has a predetermined air-fuel ratio.
It is adapted to be ignited by a spark plug 61 inside.

The ECU 15 includes a crank angle sensor 62 attached to the engine 11 for detecting the engine speed, and a pair of left and right drive 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, 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 detected. In addition to the idle switch 68 for detection, an air cleaner 69 at the tip of the intake pipe 18
An air flow sensor 70, such as a Karman vortex flowmeter, which is installed inside and detects the amount of air flowing into 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.

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

Further, 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 connected to the 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 the pair of left and right rear wheels 78 and 79, which are driven wheels, respectively, and a turning state based on the straight traveling state of the vehicle 82. The normal angle of the steering angle sensor 84 for detecting the turning angle of the steering shaft 83 and the steering wheel 85 integrated with the steering shaft 83 for every 360 degrees (including the phase in which the vehicle 82 is in a substantially straight traveling state) Is connected to the steering axis reference position sensor 86, which outputs output signals from these sensors 77, 80, 81, 84, 86, respectively.

The ECU 15 and the TCL 76 are connected via a communication cable 87, and from the ECU 15, the engine speed, the rotation speed of the output shaft 63 of the hydraulic automatic transmission 13, the detection signal from the idle switch 68, etc. Operating status information is sent to TCL76. On the contrary, the TCL76 sends information about the target drive torque calculated by the TCL76 and the retardation rate of the ignition timing to the ECU 15.

In the present embodiment, when the slip amount in the front-rear direction of the front wheels 64, 65 that are the drive wheels becomes larger than a preset amount, the drive torque of the engine 11 is reduced to ensure maneuverability and energy loss. The target drive torque of the engine 11 when the control for preventing (hereinafter, referred to as slip control) is performed, and the target drive torque of the engine 11 when the turning control is performed are calculated by TCL76, respectively, and these are calculated. Select the optimum final target drive torque from the 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 which shows the rough flow of the control according to the present embodiment, in the present embodiment, the target drive torque T _OS of the engine 11 when the slip control is performed and the target drive torque T _OS when the turning control is performed are performed. The target drive torque T _OC of the engine 11 is constantly calculated in parallel in TCL76, and these two target drive torques T _OS , T
_The optimum final target drive torque T _O is selected from _OC so that the drive torque of the engine 11 can be reduced as necessary.

Specifically, the control program of this embodiment is started by turning on the ignition key switch 75, and first at M1, the steering shaft turning position initial value δ _{m (o)} is read, various flags are reset, or sampling of this control is performed. Initial settings such as starting counting of the main timer every 15 milliseconds, which is the cycle, are performed.

Then, based on the 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
Since the neutral position δ _{M of} 83 is not stored in a memory (not shown) in the ECU 15 or the TCL 76, the initial value δ _{m (o)} is read every time the ignition key switch 75 is turned on, and the vehicle 82 will be described later. Learning correction is performed only when the straight running condition is satisfied, and this initial value δ _{m (o)} is learned and corrected until the ignition key switch 75 is turned off.

Next, TCL76 is a target drive torque T in the case of performing slip control for restricting the drive torque of the engine 11 based on the detection signals from the front wheel rotation sensor 66 and the detection signals from the rear wheel rotation sensors 80 and 81 at M4. Calculate the _OS and use M5 to measure the 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 is calculated based on the detection signals from the 0, 81 and the steering angle sensor 84.

Then, at M6, the TCL76 determines these target driving torques T _OS , T
_The optimum final target drive torque T _O is selected from _OC by a method described later mainly in consideration of safety. Furthermore, when the vehicle is suddenly started or when the road surface 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 fully closing the throttle valve 20 via the actuator 41. Therefore, the change rate G of the slip amount s of the front wheels 64 and 65 at M7
Select the retard ratio for correcting the basic retard amount p _B based on ₃ and set these final target drive torque T _O and basic retard amount.
The data regarding the retardation ratio of p _B is output to the ECU 15 by M8.

If the driver operates a manual switch (not shown) and desires slip control or turning control, the ECU 1
Reference numeral 5 is data for controlling the duty ratio of the pair of torque control solenoid valves 51, 56 so that the drive torque of the engine 11 becomes the final target drive torque T _O, and further for the retard ratio of the basic retard amount p _B. Based on the above, the target retardation amount p _O is calculated in the ECU 15, and the ignition timing P is delayed by the target retardation amount p _O as needed, whereby the vehicle 82 is allowed to travel reasonably and safely.

If the driver does not desire slip control or turning control by operating a manual switch (not shown), ECU1
5 indicates that the duty ratio of the pair of torque control solenoid valves 51, 56 is 0.
As a result of setting to the% side, the vehicle 82 is set to the driver's accelerator pedal.
The normal operating state corresponding to the depression amount of 31 is entered.

In this way, the drive torque of the engine 11 is controlled by 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. Repeat until the condition is reached.

By the way, the turning control is performed in the step of M5, and the engine 11
When calculating the target drive torque T _OC of TCL76, the TCL76 calculates the vehicle speed V based on the detection signals of the pair of rear wheel rotation sensors 80 and 81 by the following formula (1) and also based on the detection signal from the steering angle sensor 84. The steering angle δ of the front wheels 64, 65 is calculated from 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).
We are asking for each.

Where V _RL and V _RR are the peripheral speeds of the 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 wheel base 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, the target lateral acceleration G _YO of the vehicle 82 may not be able to be accurately calculated, and it becomes difficult to perform good turning control. Moreover, in the present invention, during slip control in the step of M4, since the cornering drag correction means described later corrects the reference drive torque of the engine 11 based on the turning angle δ _H of the steering shaft 83,
Slip control may not be performed well. For this reason, it is necessary to learn correct neutral position [delta] _M 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, if it is determined that the vehicle 82 in step H1 is not in the turning control, since not occur inconvenience even if the neutral position [delta] _M of the learning correction of the steering shaft 83, TCL76 the rear wheel rotation sensor 80 , based on a detection signal from 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 rear wheel speed V at H3
Difference between _RL and V _RR (hereinafter referred to as rear wheel speed difference) | V _RL −
After calculating V _RR |, the TCL 76 determines whether or not the learning correction of the neutral position δ _M is performed while the reference position δ _N of the steering shaft 83 is detected by the steering shaft reference position sensor 86 at H4. It is determined whether or not the steering angle neutral position learned flag F _HN with the reference position δ _N of the shaft 83 detected is set.

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

In this step of H5, the steering axis turning position δ _{m (n)} calculated this time is calculated from the steering axis turning position δ calculated last time.
When it is determined that the vehicle speed V is equal to _{m (n-1),} it is determined at H6 whether the vehicle speed V is higher than a preset threshold value _VA .
This operation is necessary because the rear wheel speed difference | V _RL −V _RR | due to steering cannot be detected unless the vehicle 82 reaches a certain high speed, and the threshold value V _A is the traveling characteristic of the vehicle 82. It is appropriately set, for example, at 10 km / h by an experiment based on the above.

When it is determined in step H6 that the vehicle speed V is equal to or higher than the threshold value V _A , the TCL76 determines the rear wheel speed difference | V _RL −V _{RR in} H7.
It is determined whether or not | is smaller than a threshold value V _X set in advance, such as 0.3 km / hour, that is, whether or not the vehicle 82 is in a straight traveling state. Here, the threshold V _X is not set to 0 km / h,
If the tire pressure of the left and right rear wheels 78, 79 is not equal,
This is to avoid determining that the vehicle 82 is not in the straight traveling state due to the peripheral speeds V _RL , V _{RR of the} pair of left and right rear wheels 78, 79 being different even though the vehicle 82 is in the straight traveling state. .

In the case the tire pressure of the right and left rear wheels 78 and 79 are not equal, the rear wheel speed difference | V _RL -V _RR | so has a greater tendency in proportion to the vehicle speed V, and the threshold value V _X e.g. A map may be prepared as shown in FIG. 6, and the threshold value V _X may be read from this map based on the vehicle speed V.

If it is determined in this step H7 that the rear wheel speed difference | V _RL −V _RR | is the threshold value V _X , the steering shaft reference position sensor 86 detects the reference position δ _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) incorporated in the TCL 76 is started at H9.

Next, the TCL76 determines at H10 whether or not 0.5 seconds has 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 has not elapsed since the timer started counting, it is determined in H11 whether the vehicle speed V is higher than the threshold value V _A. If it is determined in this step H11 that the vehicle speed V is higher than the threshold value V _A , the rear wheel speed difference | V _RL −V is selected in H12.
It is determined whether _RR | is less than or equal to a threshold V _{B such} as 0.1 km / h. If it is determined in this step H12 that the rear wheel speed difference | V _RL −V _RR | is less than or equal to the threshold value V _B, that is, the vehicle 82 is in a straight traveling state, then at H13, it is shown in the TCL76 No Starts the second learning timer.

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

Determines that the steering shaft reference position sensor 86 at the middle the H8 step in the iteration is detecting the reference position [delta] _N of the steering shaft 83, the counting of the first learning timer at H9 in step When 0.5 seconds have elapsed from the start of counting of the first learning timer at H10, that is, when it is determined that the straight traveling state of the vehicle 82 has continued for 0.5 seconds, the steering shaft 83 is determined at H15.
Steering angle neutral position sets the learned flag F _HN, steering angle neutral position learned flag in further state that the reference position [delta] _N of the steering shaft 83 is not detected at H16 in a state where the reference position [delta] _N has been detected Determine if F _H is set. Also, the above H1
Even when it is determined in step 4 that 5 seconds have elapsed since the second learning timer started counting, the process proceeds 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
_{The m (n)} is regarded as the neutral position δ _{M (n)} of the new steering shaft 83, and this is read into the memory in the TCL76 and the steering shaft 83 is also read.
The steering angle neutral position learned flag F _H is set when the reference position δ _N is not detected.

In this way, the new neutral position δ of the steering shaft 83 is
After setting _{M (n)} , the turning angle δ _H of the steering shaft 83 is calculated with reference to the neutral position δ _M of the steering shaft 83, while H18
At, the count of the learning timer is cleared, and the steering angle neutral position learning is performed again.

The steering shaft turning position δ _{m (n)} calculated this time in step H5 is the steering shaft turning position δ calculated last time.
_When it is determined that the vehicle speed V is not equal to _{m (n-1)} , or the vehicle speed V is not equal to or higher than the threshold value _{VA in} the step H11, that is, the rear wheel speed difference | V _RL -V _RR | calculated in the step H12. Is not reliable, or in the step of H12, the rear wheel speed difference |
If it is determined that V _RL −V _RR | is larger than the threshold V _B ,
Since the vehicle 82 is not in a straight traveling state at all, the process proceeds to the step of H18 in the previous term.

In the step H7, the rear wheel speed difference | V _RL −V _RR |
If it is determined that it is larger than V _X , or if it is determined in step H8 that the steering shaft reference position sensor 86 has not detected the reference position δ _N of the steering shaft 83, the first learning is performed in H19. Although the count of the use timer is cleared and the process shifts to the step of H11, even if it is determined in the step of H6 that the vehicle speed V is equal to or lower than the threshold value V _A , it cannot be determined that the vehicle 82 is in the straight traveling state. , Go to step H11.

On the other hand, in the step H4, the reference position δ _{N of the} steering shaft 83 is set.
If the steering angle neutral position learning completion flag F _HN is set in the state where is detected, and it is judged that the learning of the fast neutral position δ _M is the second time or later, the steering axis reference position is set at H20. It is determined whether or not the sensor 86 detects the reference position δ _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.

When it is determined in this step H21 that the vehicle speed V is equal to or higher than the threshold value V _A , the TCL76 sets the rear wheel speed difference | 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, if it is determined in this step H22 that the rear wheel speed difference | V _RL −V _RR | is smaller than the threshold value V _X , the steering shaft turning position δ _{m (n)} calculated this time in H23 is the previous time. Calculated steering axis turning position δ
_It is determined whether it is equal to _{m (n-1)} . If it is determined in this step H23 that the steering axis turning position δ _{m (n)} calculated this time is equal to the steering axis turning position δ _{m (n-1)} calculated last time, the above-mentioned first step is executed in H24. Start the counting of the learning timer.

Next, the TCL76 determines at H25 whether or not 0.5 seconds has elapsed from the start of counting of this first learning timer, that is, whether the straight traveling state of the vehicle 82 has continued for 0.5 seconds, and the first learning timer If 0.5 seconds has not elapsed from the start of counting, the process returns to the step H2, and the steps H2-H4 and H20-H25 are repeated. On the contrary, if it is determined in step H25 that 0.5 second has elapsed from the start of counting by the first learning timer, the process proceeds to step H16.

The steering shaft reference position sensor 8
6 determines that the reference position δ _N of the steering shaft 83 is not detected, or the vehicle speed V is not equal to or higher than the threshold value _{VA in} the step H21, that is, the rear wheel speed difference | calculated in the step H22 | V _RL
−V _RR | is not reliable, or the rear wheel speed difference | V _RL −V _RR | is larger than the threshold value V _X in step H22, or this time in step H23. If it is determined that the calculated steering axis turning position δ _{m (n)} is not equal to the previously calculated steering axis turning position δ _{m (n-1)} , the process proceeds to step H18.

Rudder angle neutral position learned flag F _{H in} step H16
If it is determined that the learning of the toe neutral position δ _M has been performed for the second time or later, the current steering shaft turning position δ _{m (n)} at H26 of the TCL76 is the neutral position δ of the previous steering shaft 83.
It is determined whether it is equal to _{M (n-1)} , that is, δm _(n) = δM _(n-1) . The current steering shaft turning position δ _{m (n)} is the neutral position δ of the previous steering shaft 83.
If it is determined that it is equal to _{M (n-1)} , H18 is used as it is.
Then, the next steering angle neutral position learning is performed.

At step H26, the current steering shaft turning position δ
_{m (n)} is due to play in the steering system, etc.
If it is determined not equal to the neutral position of _{83 δ M (n-1)} , in this embodiment the current steering shaft turning position [delta] _m and the neutral position of the _(n) as a new steering shaft 83 [delta] _{M (n)} Without making a judgment, the absolute value of these differences is the preset correction control amount Δδ.
If there is any difference, the previous steering shaft turning position δ
_A new neutral position δ _{M (n) of the} steering shaft 83 is obtained by subtracting or adding the correction limiting amount Δδ from _{m (n−1)} , and this is read into the memory in the TCL 76.

In other words, TCL76 indicates the current steering shaft turning position δ at H27.
_{From m (n)} to the previous neutral position δ _{M (n-1)} of the steering shaft 83
It is determined whether the value obtained by subtracting is smaller than a preset negative correction limit amount −Δδ. When it is determined that the value subtracted in step H27 is smaller than the negative correction limit amount −Δδ, the neutral position δ _{M (n)} of the new steering shaft 83 is set to the value of the previous steering at H28. Axis 83 neutral position δ
_{M (n-1)} and negative correction limit amount -Δδ are changed to δ _{M (n)} = δ _{M (n-1)} −Δδ, and the learning correction amount per time is unconditionally increased to the negative side. We are careful not to become.

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.

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 neutral position of the steering shaft 83 from the current steering shaft turning position δ _{m (n)} to the previous steering shaft 83 is neutralized in H29. The correction limit amount Δ whose value obtained by subtracting the position δ _{M (n-1)} is positive
It is determined whether it is larger than δ. When it is determined that the value subtracted in step H29 is larger than the positive correction limit amount Δδ, the neutral position δ _{M (n)} of the new steering shaft 83 is set to the previous steering shaft 83 at H30. Neutral position δ
Change from _{M (n-1)} and positive correction limit amount Δδ to δ _{M (n)} = δ _{M (n-1)} + Δδ so that the learning correction amount per time does not unconditionally increase to the positive side. Is considered.

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 subtracted 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 new neutral position of the steering shaft 83 in H31. Read as δ _{M (n)} as it is.

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
_As shown in FIG. 7 showing an example of a change state of _M , the steering shaft
When the learning control of the neutral position δ _M of 83 is the first time, the correction amount from the initial value δ _{m (o)} of the steering shaft turning position in the step of M1 described above becomes very large, but the second and subsequent steering The neutral position δ _M of the shaft 83 is suppressed by the operation in steps H17 and H19.

After the neutral position δ _M of the steering shaft 83 is learned and corrected in this way, the drive torque of the engine 11 is regulated based on the detection signals from the front wheel rotation sensor 66 and the rear wheel rotation sensors 80 and 81. Target drive torque for step control
Calculate T _OS .

By the way, since the coefficient of friction between the tire and the road surface can be regarded as equivalent to the rate of change of the vehicle speed V applied to the vehicle 82 (hereinafter, referred to as longitudinal acceleration) G _X , this longitudinal acceleration is used in this embodiment. G _X is calculated based on the detection signals from the rear wheel rotation sensors 80 and 81, and the reference drive torque T _B of the engine 11 corresponding to the maximum value of this longitudinal acceleration G _X is detected by the front wheel rotation sensor 66. The target drive torque T _OS is calculated by making a correction based on a deviation (hereinafter, referred to as a slip amount) s between the speed V _F and the target front wheel speed V _FO corresponding to the vehicle speed V.

As shown in FIG. 8 showing a calculation block for calculating the target drive torque T _OS of the engine 11, first, the TCL 76 determines the vehicle speed V _S for slip control based on the detection signals from the rear wheel rotation sensors 80, 81. In the present embodiment, the low vehicle speed selection unit 101 selects the smaller one of the two rear wheel speeds V _RL and V _RR as the first vehicle speed V _S for slip control and calculates the high vehicle speed. In the selection unit 102, the larger one of the two rear wheel speeds V _RL , V _RR of the circle is selected as the second vehicle speed V _S for slip control, and then the changeover switch 103 is used to select one of the two selection units 101, 102. Further, it is possible to further select which of the outputs in the table is to be captured.

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

That is, the state where the drive torque of the engine 11 is actually reduced by the slip control, that is, the slip control flag F _S
In the set state, 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 the drive torque of the engine 11 is reduced even if the driver desires slip control. In the state where the reduction is not performed, that is, the state in which the flag F _S during slip control is reset, the two rear wheel speeds V _RL ,
The larger value of V _RR is selected as the vehicle speed V _S.

This is because it is difficult to shift from the state where the drive torque of the engine 11 is not reduced to the state where the drive torque of the engine 11 is reduced, and at the same time, the transition in the opposite case is also difficult. For example, when the smaller value of the two rear wheel speeds V _RL and V _RR during turning of the vehicle 82 is selected as the vehicle speed V _S , slip occurs even though the front wheels 64 and 65 have not slipped. To avoid the problem that the drive torque of the engine 11 is reduced.
This is because, in consideration of the traveling safety of 82, it was considered that this state would be continued once the drive torque of the engine 11 was reduced.

Further, when the vehicle speed V _S is calculated by the low vehicle speed selection unit 101, the smaller value V _L of the two rear wheel speeds V _RL and V _RR is multiplied by the weighting coefficient K _V in the multiplication unit 104. , This and two rear wheel speeds
The larger value V _H of V _RL and V _RR is multiplied by (1-K _V ) 105
Is added to the value obtained by multiplying by, for example, when traveling in a turning circuit with a small radius of curvature such as turning left or right at an intersection, etc.
As a result, the average value of the peripheral speeds of the front wheels 64 and 65 and the smaller value V _{L of the} two rear wheel speeds V _RL and V _RR greatly differ, and as a result, the correction amount of the drive torque by feedback is too large. This is because the acceleration performance of the vehicle 82 may be impaired.

In this embodiment, the weighting coefficient K _{V is set} to the rear wheels 78,7.
The map is read out as shown in FIG. 9 on the basis of the vehicle speed V of the equation (1) which is the average value of the peripheral speeds of 8.

The longitudinal acceleration G _X is calculated based on the slip control vehicle speed V _S calculated in this way. First, the vehicle speed V _{s (n)} calculated this time and the vehicle speed V _{S (n−1 )} calculated one time before are calculated. ₎
From the above, the current longitudinal acceleration G _{X (n)} of the vehicle 82 is calculated by the differential calculation unit 106 as in the following equation.

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

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 calculation errors. As described above, the longitudinal acceleration G _{X (n)} is 0.6 at the clip portion 107.
Clip to g. Further, the filter unit 108 performs filter processing for noise removal to calculate the corrected longitudinal acceleration G _XF .

This filtering process is performed by measuring the longitudinal acceleration G _{X (n)} of the vehicle 82.
Can be regarded as equivalent to the friction coefficient between the tire and the road surface, and therefore, the maximum value of the longitudinal acceleration G _{X (n)} of the vehicle 82 changes and the slip ratio S of the tire becomes the friction coefficient between the tire and the road surface. Even when the target slip ratio S _O corresponding to the maximum value or the vicinity thereof is about to be deviated, the slip ratio S of the tire is set to the target slip ratio S _O corresponding to the maximum value of the friction coefficient between the tire and the road surface or the vicinity thereof. This is for correcting the longitudinal acceleration G _{X (n)} so as to maintain the value smaller than this value, and specifically, it is performed as follows.

If the current longitudinal acceleration G _{X (n)} is _{equal to} or greater than the filtered previous longitudinal acceleration G _{XF (n−1)} , that is, when the vehicle 82 continues to accelerate, the current longitudinal acceleration G _{XF (n )} is increased. ₎ As a result, noise is removed by delay processing, and the corrected longitudinal acceleration G _{XF (n)} follows the longitudinal acceleration G _{X (n)} relatively quickly.

When the longitudinal acceleration G _{X (n)} of this time is less than the modified longitudinal acceleration G _{XF (n−1) of the} previous time, that is, when the vehicle 82 is not accelerated too much, the following processing is performed at every sampling period Δt of the main timer.

In the state where the slip control flag F _S is not set, that is, the drive torque of the engine 11 is not reduced by the slip control, the vehicle 82 is decelerating, so G _{XF (n)} = G _{XF (n-1)} A value of −0.002 suppresses a decrease in the corrected longitudinal acceleration G _{XF (n)} , and ensures responsiveness to the driver's request for acceleration of the vehicle 82.

Further, even when the slip amount s is positive while the drive torque of the engine 11 is being reduced by the slip control, that is, when the front wheels 64 and 65 are slightly slipped, the vehicle 82 is decelerating and therefore safety is ensured. Since G _{XF (n)} = G _{XF (n−1)} −0.002, the correction longitudinal acceleration G _XF is suppressed from decreasing, and the responsiveness to the acceleration request of the vehicle 82 by the driver is secured.

Further, when the slip torque s of the front and rear 64, 65 is negative while the drive torque of the engine 11 is being reduced by the slip control, that is, when the vehicle 82 is decelerating, the maximum value of the corrected longitudinal acceleration G _XF is held, The responsiveness to the driver's request for acceleration of the vehicle 82 is ensured.

Similarly, when the hydraulic control device 16 shifts up the hydraulic automatic transmission 13 while the drive torque of the engine 11 is reduced by the slip control, it is necessary to secure a feeling of acceleration for the driver, and the corrected longitudinal acceleration 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 converted into torque by the torque conversion unit 109, but the value calculated by this torque conversion unit 109 is naturally a positive value. Since it should be a value, the grip unit 110 clips this to 0 or more in order to prevent a calculation error, and then the running resistance T _R calculated by the running resistance calculation unit 111 is added by the addition unit 112. Then, 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 drive shown in the following formula (4) is performed. 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 traveling resistance T _R can be calculated as a function of the vehicle speed V, but in the present embodiment, it is obtained from the map shown in FIG. In this case, the running resistance T _R between the flat road and the uphill road
Therefore, in the figure, for the flat road shown by the solid line and for the climbing road shown by the chain double-dashed line in the map, based on the detection signal from the tilt sensor (not shown) incorporated in the vehicle 82, Although either one is selected, it is possible to further finely set the traveling resistance T _R including a downhill or 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 drive torque calculated by the equation (4)
With respect to T _B , in the present embodiment, the lower limit value is set by the variable grip unit 115, so that the value obtained by subtracting the final correction torque T _PID, which will be described later, from the reference drive torque T _B by the subtraction unit 116 is negative. We prevent such a problem. As shown in the map shown in FIG. 12, the lower limit value of the reference drive torque T _B is gradually reduced according to the elapsed time from the start of slip control.

On the other hand, the TCL 76 calculates the actual front wheel speed V _F based on the detection signal from the front wheel rotation sensor 66, and as described above, is set based on the front wheel speed V _F and the vehicle speed V _S for slip control. By performing feedback control of the reference drive torque T _B using a slip amount s that is a deviation from the target front wheel speed V _FS for correction torque set based on the target front wheel speed V _FO Calculate the driving torque T _OS .

By the way, in order to make effective use of the drive torque generated in the engine 11 during acceleration of the vehicle 82, as shown by the solid line in FIG. 13, the slip ratio S of the tires of the front wheels 64, 65 during traveling is
Is adjusted so that the maximum value of the coefficient of friction between the tire and the road surface and the corresponding target slip ratio S _O or a value near the target slip ratio S _O are smaller than this value, to avoid energy loss and control performance and acceleration of the vehicle 82. It is desirable not to impair performance.

Here, the target slip ratio S _O is 0.1 depending on 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 V _O is set by the multiplying unit 117 according to the following equation.

V _FO = 1.1 · V Then, the TCL 76 reads the slip correction amount V _K corresponding to the above-mentioned corrected longitudinal acceleration V _XF from the map shown in FIG. 14 in the acceleration correction unit 118, and uses this as the reference in the addition unit 119. Add to target front wheel speed V _FO for torque calculation. The slip correction amount V _K has a tendency to increase stepwise as the value of the corrected longitudinal acceleration G _XF increases, but in this embodiment, this map is created based on a running test or the like. There is.

As a result, the target front wheel speed V _FS for correction torque calculation is increased, and the slip ratio S during acceleration is set to a value smaller than the target slip ratio S _O shown by the solid line in FIG. 13 or in the vicinity thereof. To be done.

On the other hand, the coefficient of friction between the tire and the road surface during turning,
As shown by the alternate long and short dash line in FIG. 13 with respect to the tire slip ratio S, the tire slip ratio, which is the maximum friction coefficient between the tire and the road surface during turning, is It can be seen that the friction coefficient is significantly smaller than the target slip ratio S _{O of the} tire, which is the maximum value. Therefore, it is desirable to set the target front wheel speed V _FO smaller than that when the vehicle is straight ahead so that the vehicle 82 can smoothly turn 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 as shown by the solid line in FIG. 15, and the subtraction unit 121 reads it out from the target front wheel speed V for calculating the reference torque. Subtract from _FO . However, until the first neutral position δ _M of the steering shaft 83, which is performed after the ignition key switch 75 is turned on, is learned.
Because of unreliable swivel angle [delta] _H, the peripheral speed of the rear wheels 78, 79 V
Based on the lateral acceleration G _Y actually acting on the vehicle 82 by _RL and V _RR , the slip correction amount V _KC is read from the map as 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 axis reference position sensor 86
If an abnormality occurs in the target lateral acceleration G _YO, it is possible that the target lateral acceleration G _YO will be a completely incorrect value. Therefore, if an abnormality occurs in the steering angle sensor 84 or the like, the actual lateral acceleration G _Y generated in the vehicle 82 is calculated using the rear wheel speed difference | V _RL −V _RR |, and this is calculated as the target lateral acceleration. _{Used instead} of G _YO .

Specifically, this actual lateral acceleration G _Y 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

However, b is the tread of the rear wheels 78 and 79, and the filter unit 123 uses the lateral acceleration G _{Y (n)} calculated this time and the corrected lateral acceleration G _{YF (n−1)} calculated last time to correct the lateral acceleration this time. Low-pass processing is performed on G _{YF (n)} by digital calculation shown in the following equation.

Whether or not 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 a disconnection detection circuit or the like shown in FIG. 16, for example. That is, the outputs of the steering angle sensor 84 and the steering axis 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 TCL76 and used for various controls. It is input to the A1 terminal through the comparator 88. A specified value of 4.5 V is applied as a reference voltage to the negative terminal of the comparator 88, and when the steering angle sensor 84 is disconnected, the input voltage at the A0 terminal exceeds the specified value and the comparator 88 turns on and the A1 terminal The input voltage continues to be 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, 2 seconds, the program of the TCL76 is determined so as to judge that the wire is broken and detect the occurrence of an abnormality in the steering angle sensor 84 or the steering axis reference position sensor 86. It is set.

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

For example, as shown in FIG. 17 showing an example of this abnormality detection procedure, TCL76 first determines the abnormality by the disconnection detection shown in FIG. 16 at W1, and if it is determined that it is not abnormal, Front wheel rotation sensor 66 and rear wheel rotation sensor 8 at W2
It is determined whether or not 0 and 81 are abnormal. When it is determined that there is no abnormality in each rotation sensor 66, 80, 81 in the step of W2, the steering shaft 83 has one rotation abnormality in the same direction in W3, for example,
It is judged whether or not the steering is abnormally performed by 400 degrees. In the case where the steering shaft 83 is determined in step W3 it was judged steering over 400 degrees in the same direction, whether or not there is a signal indicating the reference position [delta] _N of the steering shaft 83 from the steering shaft reference position sensor 86 at W4 Judge.

Then, in this step of W4, the reference position δ of the steering shaft 83
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 ,
When it is judged that the steering angle sensor 84 is abnormal at W4, step
At W9, set the error occurrence flag _FW .

When it is determined in step W3 that the steering shaft 83 is not abnormally steered in the same direction by 400 degrees, or in step W4, a signal notifying the reference position δ _N of the steering shaft 83 is output from the steering shaft reference position sensor 86. If it is determined that it is, whether or not the learning of the neutral position δ _M has been completed at W5, that is, whether or not at least one of the two steering angle neutral position learned flags F _HN and F _H is set. To determine.

In the step of W5, the neutral position δ _{M of the} steering shaft 83 is set.
If it is determined that learning of the vehicle has been completed, the rear wheel speed difference | V _RL −V _RR | exceeds, for example, 1.5 km / h at W6, and the vehicle speed V at W7.
Is between 20 km / h and 60 km / _h , and the absolute value of the turning angle δ _H of the steering shaft 83 at W8 is, for example, less than 10 degrees, that is, the vehicle 82 is turning at a certain speed. If it is determined that the steering angle sensor 84 is functioning normally, the absolute value of the turning angle δ _H should be 10 degrees or more. Therefore, it is determined that the steering angle sensor 84 is abnormal. Judgment is made, and in step W9, an abnormality occurring flag Fw is set.

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. If the vehicle speed V is low,
It is desirable to secure the acceleration of 82, and conversely this vehicle speed V
When the speed is above a certain level, it is necessary to consider the ease of turning, so the slip correction amount read from Fig. 15
The corrected slip correction amount V _KF is calculated by reading V _KC and a correction coefficient corresponding to the vehicle speed V from the map shown in FIG. 18 and multiplying it.

As a result, the target front wheel speed V _FO for calculating the correction torque decreases, the slip ratio S during turning becomes smaller than the target slip ratio S _O during straight running, and the acceleration performance of the vehicle 82 slightly deteriorates, but good turning is achieved. Sex is secured.

As shown in FIG. 19 showing the procedure for selecting the target lateral acceleration G _YO and the actual lateral acceleration G _Y , the TCL76 sets the lateral acceleration for calculating the slip correction amount V _KC at T1 from the filter unit 123. The corrected lateral acceleration G _YF is adopted and it is determined at T2 whether or not the slip control flag F _S is set.

If it is determined in step T2 that the slip control flag F _S is set, the corrected lateral acceleration G _YF
Is adopted as is. This is because when the lateral acceleration, which is the reference for determining the slip correction amount V _KC during slip control, is changed from the corrected lateral acceleration G _YF to the target lateral acceleration G _YO , the slip correction amount V _KC changes greatly and the vehicle 82 This is because there is a possibility that the behavior of is 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 in step T3 that one of the two steering angle neutral position learned flags F _HN , F _H is set, in step T4 the step correction amount V _KC is calculated. The target lateral acceleration G _YO is adopted as the lateral acceleration of.

As a result, the target front wheel speed V _FS for correction torque calculation is given by the following equation.

V _FS = V _FO + V _K −V _F Next, the actual front wheel speed V _F obtained from the detection signal of the front wheel rotation sensor 66 by filtering for the purpose of noise removal,
A subtraction unit 124 calculates a slip amount s which is a deviation from the target front wheel speed V _FS for correction torque calculation. When the slip amount s is less than or equal to a negative set value, for example, −2.5 km / h or less, −2.5 km / h as the slip amount s is clipped by the clip unit 15, and the slip amount s after the clipping process is set. On the other hand, a proportional correction which will be described later is performed to prevent over-control in the proportional correction so that output hunting does not occur.

Further, the final correction torque T _PID is calculated by performing integral correction using a later-described integral constant ΔT _i on the slip amount s before the clipping process and further performing differential correction.

As the proportional correction, the slip amount s
To determine the basic correction amount by multiplying the proportional coefficient K _P, further proportional correction torque T by multiplying a preset correction coefficient [rho _KP by the gear ratio [rho _m of hydraulic automatic transmission 13 at the multiplying unit 127 _P
Is getting The proportional coefficient K _P is read from the map shown in FIG. 20 according to the slip amount s after the clipping process.

In addition, in order to realize a correction corresponding to a gradual change in the slip amount s as the integral correction, a basic correction amount is calculated by the integration operation unit 128, and this correction amount is multiplied by the multiplication unit 12
At 9, the correction coefficient ρ _KI set in advance based on the gear ratio ρ _m of the hydraulic automatic transmission 13 is multiplied, and the integrated correction torque T _I
Is getting In this case, in the present embodiment, the constant differential integral correction torque ΔT _I is integrated, and when the slip amount s is positive every 15 ms sampling period, the minute integral correction torque ΔT _I is added, and the inverse If the slip amount s is negative, the minute integral correction torque ΔT _I is subtracted.

However, the lower limit value T _IL as shown in the map of FIG. 21 which is variable according to the vehicle speed V is set to this integral correction torque T _I , and this clipping process allows the vehicle 82 to start, especially on an uphill road. At the time of starting, a large integral correction torque T _I is applied to secure the driving force of the engine 11, and after the vehicle speed V increases after starting the vehicle 82, on the contrary, if the correction is too large, the stability of the control is lost. The correction torque T _I is made smaller. In addition, the integral correction torque T _I
The upper limit value, 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 ₃ 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. Then, the upper limit value and the lower limit value are respectively set to the values obtained by this, and clipping processing is performed by the clipping unit 133 so that the differential correction torque T _D does not become an extremely large value. I'm getting _D. The clip portion 133 is _{designed to reduce} wheel speeds V _F , V _RL , V while the vehicle 82 is traveling.
_RR may momentarily slip or lock depending on the road surface condition, the running state of the vehicle 82, etc. In such a case, the change rate G ₃ of the slip amount s becomes a positive or negative extremely large value, Since the control may diverge and the responsiveness may decrease, for example, the lower limit value is clipped to −55 kgm and the upper limit value is clipped to 55 kgm so that the differential correction torque T _D does not become an extremely large value. It is a thing.

Then, the adder unit 134 adds the proportional-integral correction torque T _PI and the derivative correction torque T _D, and the final correction torque T _PID obtained by the addition is subtracted from the reference drive torque T _B by the calculation unit 116. Then, the multiplication unit 135 further multiplies the reciprocal of the total reduction ratio between the engine 11 and the axles 89, 90 of the front wheels 64, 65 to obtain the target drive torque T for slip control shown in the following equation (6). Calculate the _OS .

However, ρ _d is a differential gear reduction ratio, ρ _T is a torque converter ratio, and when the hydraulic automatic transmission 13 performs an upshift gear shifting operation, after the gear shifting is completed, the high speed gear side The gear ratio ρ _m is output. That is, in the case of the upshift gear shifting operation of the hydraulic automatic transmission 13, if the gear ratio ρ _m on the high speed stage side is adopted at the time of outputting the gear shift signal, as is apparent from the above equation (6), Since the target drive torque T _OS increases and the engine 11 blows up, the gear change operation is completed after the gear change start signal is output. For example, at a low speed for 1.5 seconds, the target drive torque T _OS can be made smaller. The gear ratio ρ _m on the gear side is held, and the gear ratio ρ _m on the high gear side is adopted 1.5 seconds after the signal for starting gear shift is output. For the same reason, hydraulic automatic transmission
In the case of 13 downshift gear shifting operations, the gear ratio ρ _m on the low speed side is immediately adopted at the time of outputting the gear shift signal.

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
In 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 in the start / end determination unit 137 for determining the start or end of the slip control. Information about the _OS is output to ECU15.

The start / end determination unit 137 determines that the slip control is to be started when all the conditions (a) to (e) below are satisfied, sets the slip control in-progress flag F _S, and outputs from the low vehicle speed selection unit 101. The selector switch 103 is operated to select the output as the vehicle speed V _S for slip control, information about the target drive torque T _OS is output to the ECU 15, and the slip control in-progress flag F _S is reset when the end of slip control is judged. This process is continued until.

(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 T _d is 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 G ₃ 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 of the differentiating unit 138 is not less than 0.2 g.

On the other hand, after the start / end determination unit 137 determines that the slip control is started, if either of the following conditions (f) and (g) is satisfied, it is determined that the slip control is completed and the slip control is completed. The control flag F _S is reset, the transmission of the target drive torque T _OS to the ECU 15 is stopped, and the changeover switch 103 is operated so as to select the output from the high vehicle speed selection unit 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 slip amount s is a constant value, for example, −2 km / hour or less, for a predetermined time, for example, 0.5 seconds or more.

(G) The state in which the idle switch 68 is changed from off to on, that is, the state in which the driver releases the accelerator pedal 31 continues for a certain 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 slip control of the slip control described below is performed. Do the operation.

As shown in FIG. 25 showing the flow of this slip control processing, the TCL75 calculates the target drive torque T _OS by the detection and calculation processing of various data described above in S1, but this calculation operation is the manual switch. It is performed regardless of the operation of.

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
Determine if it is greater than m.

If it is determined in step S3 that the slip amount s is greater than 2 km / h, the TCL 76 determines in step S4 whether the rate of change G _s of the slip amount s is greater than 0.2 g.

When it is determined in step S4 that the slip amount change rate G _s is larger than 0.2 g, the TCL76 determines in S5 that the driver's required drive torque T _d is the minimum drive torque required to drive the vehicle 82, for example, 4 kgm. Is larger than that, that is, whether or not the driver intends to drive the vehicle 82.

If it is determined in step S5 that the required drive torque T _d is larger than 4 kgm, that is, the driver intends to drive the vehicle 82, the slip control flag F _S is set in step S6, and the slip is set in step S7. It is again determined whether or not the control flag F _S is set.

When it is determined in step S7 that the slip control flag F _S is being set, the target drive torque T _OS of the engine 11 is calculated in advance in S8 as the slip control flag F _S for slip control. Adopt target drive torque T _OS .

If it is determined in step S7 that the slip control flag F _S has been reset, TCL76 is set in step S9.
Outputs the maximum torque of the engine 11 as the target drive torque T _OS , whereby the ECU 15 reduces the duty ratio of the torque control solenoid valves 51, 56 to the 0% side, and as a result, the engine 11 operates the accelerator pedal 31 of the driver. Drive torque is generated according to the amount of depression.

If it is determined in step S3 that the slip s of the front wheels 64, 65 is smaller than 2 km / h, or if it is determined in step S4 that the slip amount change rate G _s is smaller than 0.2 g, or S5 The required drive torque T _d is 4k in the step
When it is determined that the value is smaller than gm, the process directly shifts to the step S7, and in the step S9, the TCL76 outputs the maximum torque of the engine 11 as the target drive torque T _OS.
CU15 sets the duty ratio of torque control solenoid valves 51, 56 to 0%
As a result of the reduction to the side, the engine 11 generates a drive torque according 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 at S10
It is determined whether the state where the slip amount s of 4,65 is equal to or less than the threshold value of −2 km / hour and the required drive torque T _d is equal to or less than the target drive torque T _OS calculated in S1 is continued for 0.5 seconds or more. To do.

In this step of S10, the state where the slip amount s is smaller than 2 km / h and the required drive torque T _d is equal to or less than the target drive torque T _OS continues for 0.5 seconds or more, that is, the driver
If it is determined that the acceleration of No. has not been desired, the slip control flag F _S is reset in S11, and the process proceeds to step S7.

In the step S10, the slip amount s is larger than 2 km / h, or the required drive torque T _d is the target drive torque T
_{If the} driver determines that the state below _OS is not maintained for 0.5 seconds or more, that is, the driver wants to accelerate the vehicle 82, the TCL76 sets S
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 it is determined in step S12 that the idle switch 68 is on, the driver has not stepped on the accelerator pedal 31, so the process proceeds to step S11 to reset the slip control flag F _S. On the other hand, when it is determined that the idle switch 68 is off, the driver depresses the accelerator pedal 31, so the process proceeds to step S7 again.

When the driver does not operate the manual switch for selecting the slip control, the TCL76 calculates the target drive torque T _OS for the slip control as described above, and then the engine 11 when the turning control is performed. Calculate the target drive torque.

Incidentally, the lateral acceleration G _Y of the vehicle 82 rear wheel speed difference | V _RL -V _RR |
Although it can be actually calculated by using the equation (5) above, the value of the lateral acceleration G _Y acting on the vehicle 82 can be predicted by transferring the steering shaft turning angle δ _H. , 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 this target longitudinal acceleration G _XO is calculated.

As shown in FIG. 26 showing the calculation block of this turning control, the TCL 76 uses a pair of rear wheel rotation sensors 8 in the vehicle speed calculation unit 140.
The vehicle speed V is calculated from the output of 0,81 by the equation (1), and the front wheels 64,6 based on the detection signal from the steering angle sensor 84.
The steering angle δ of 5 is calculated from the equation (2), and the target lateral acceleration computing unit 141 calculates the target lateral acceleration G _YO of the vehicle 82 at this time from the equation (3). In this case, when the vehicle speed V is small, for example, when the vehicle speed is 22.5 km / h 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 or right at an intersection with a large amount of traffic. Since it is often convenient in terms of safety, in the present embodiment, the correction coefficient multiplication unit 142 sets the correction coefficient K _Y as shown in FIG. 27 to the target lateral acceleration G _YO according to the vehicle speed V. Multiplying.

By the way, in the state where the learning of the steering shaft center position δ _M is not performed, there is a problem in reliability in calculating the target lateral acceleration G _YO based on the steering angle δ. It is desirable not to start the turning control until the axis neutral position δ _M is learned. However, when the vehicle 82 travels on a curved road immediately after the start of traveling, the vehicle 82 is in a state in which turning control is required.
_Since the learning start condition of _M is not easily satisfied, there is a possibility that this turning control may not start. Therefore, until the present embodiment is performed the learning of steering shaft neutral position [delta] _M is to perform the turning control by using the modified lateral acceleration G _YF from the filter unit 123 based on the equation (5) by the changeover switch 143 I have to. That is, when both of the two steering angle neutral position learned flags F _HN and F _H are reset, the correction lateral acceleration G _YF is changed by the changeover switch 143.
If at least one of the two steering angle neutral position learned flags F _HN and F _H is set, the changeover switch 143 is used to set the target lateral acceleration G from the correction coefficient multiplication unit 142.
_YO is selected.

Further, 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, etc., 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
The ratio of the turning angle δ _HO of the steering shaft 83 in a very low speed traveling state in which the lateral acceleration G _Y is close to 0 with respect to the ratio of the turning angle δ _H of the steering shaft 83 during acceleration) It is expressed as the slope of the tangent in the graph shown in Fig. 28. That is, in a region where the lateral acceleration G _Y is small and the vehicle speed V is not too high, the stability factor A is almost constant (A
However, when the lateral acceleration G _Y exceeds 0.6 g, the stability factor A sharply increases, and the vehicle 82 shows an extremely strong understeering tendency.

From the above, the paved road surface in the dry state (hereinafter,
(This is called the high μ road) Based on FIG. 28 corresponding to the high μ road, set the stability factor A 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 about 0.005. in this case,
On a low μ road, the target lateral acceleration G _YO is larger than the actual lateral acceleration G _Y, so whether the target lateral acceleration G _YO is larger than a preset threshold value, for example (G _YF -2). If 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 turning control for the low μ road may be performed as necessary. Specifically, the corrected lateral acceleration G _YF calculated based on the equation (5) is 0.0
Whether the target lateral acceleration G _YO than a preset threshold value by adding 5g is large, that is because the direction of the target lateral acceleration G _YO than the actual lateral acceleration G _Y is a low μ road is a large value, the target It is determined whether the lateral acceleration G _YO is greater than this threshold value, and if the target lateral acceleration G _YO is greater than the threshold value, it is determined that the vehicle 82 is traveling on a low μ road.

After calculating the target lateral acceleration G _YO in this way,
The target longitudinal acceleration G _XO of the vehicle 2 set in advance according to the magnitude of the target lateral acceleration G _YO and the vehicle speed V is stored in the TCL 76 by the target longitudinal acceleration calculating unit 144 from the map as shown in FIG. 29. The reference drive torque T _B of the engine 11 corresponding to this target longitudinal acceleration G _XO is read out and the reference drive torque calculation unit
It is calculated by the following equation (7) at 145.

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

Here, according to the steering shaft turning angle δ _H and the vehicle speed V, the engine
Only by obtaining the target drive torque of 11, the driver's intention is not reflected at all, and there is a possibility that the driver remains dissatisfied with respect to the maneuverability of the vehicle 82. For this reason, the driver's desired engine 11
Seeking the requested driving torque T _d from the depression amount of the accelerator pedal 31, it is desirable to set the target drive torque of the engine 11 in consideration of the required driving torque T _d.

Therefore, in the present embodiment, in order to determine the adoption ratio of the reference drive torque T _B , the multiplying unit 146 multiplies the reference drive torque T _B by the weighting coefficient α to obtain the corrected reference drive torque.
This weighting coefficient α is set empirically by turning the vehicle 82, but on a high μ road, a value around 0.6 is adopted.

On the other hand, the required drive torque T _d desired by the driver is shown in FIG. 29 based on the engine speed N _E detected by the crank angle sensor 55 and the accelerator opening θ _A detected by the accelerator opening sensor 77. Obtained from the map as shown, then multiplying unit 14
In step 7, the correction request drive torque corresponding to the weighting coefficient α is calculated by multiplying the request drive torque T _d by (1-α). For example, when α = 0.6 is set,
The adoption ratio of the standard drive torque T _B and the required drive torque T _d is 6
It becomes pair 4.

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

T _OC = α ・ T _B + (1-α) ・ T _d (8) By the way, when the increase / decrease amount of the target drive torque T _OC of the engine 11 set every 15 milliseconds is very large, When a shock is generated due to acceleration / deceleration of the vehicle 82 and the ride comfort is reduced, when the increase / decrease in the target drive torque T _OC of the engine 11 is large enough to reduce the ride comfort of the vehicle 82. It is desirable to regulate the increase / decrease amount of this target drive torque T _OC .

Therefore, in this 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 in the change amount clipping unit 149 is increased / decreased. If it is smaller than the capacity T _K , the calculated target drive torque T _{OC (n)} of this time is directly used, but the target drive torque T _{OC (n)} calculated this time and the target drive torque T _{OC ( n-1)} is not larger than the negative increase / decrease allowable amount T _K , the target drive torque T of this time
_{OC (n)} is set by the following formula.

T _{OC (n)} = T _{OC (n−1)} −T _K That is, the target drive torque T _{OC (n−1)} calculated last time
The decrease width regulated by increasing or decreasing tolerance T _K for, reducing the deceleration shock caused by drive torque reduction of the engine 11. Further, when the difference ΔT between the target drive torque T _{OC (n)} calculated this time and the target drive torque T _{OC (n−1)} calculated last time is equal to or larger than the increase / decrease allowable amount T _K , the target drive torque T _{OC of} this time _(N) is set by the following formula.

T _{OC (n)} = T _{OC (n−1)} + T _K That is, the difference ΔT between the target drive torque T _{OC (n)} calculated this time and the target drive torque T _{OC (n−1)} calculated last time is the increase / decrease allowable amount. When T _K is exceeded, the increase range for the target drive torque T _{OC (n−1)} calculated last time is restricted by the increase / decrease allowable amount T _K , and the acceleration shock accompanying the increase in the drive torque of the engine 11 is reduced.

Then, along with the determination processing by the start / end determination unit 150 for determining the start or end of the turning control, the information regarding the target drive torque T _OC is output to the ECU 15.

The start / end determination unit 150 determines that the turning control is started when all the conditions (a) to (d) below are satisfied,
Target drive torque with turning control flag F _C set
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 driver desires turning control by operating a manual switch (not shown).

(C) The idle switch 68 is off.

(D) The control system for turning is normal.

On the other hand, when the start / end determining unit 150 determines that the turning control is started and either of the following conditions (e) and (f) is satisfied, it is determined that the turning control is finished and the turning is ended. The in-control flag F _C is reset and the transmission of the target drive torque T _OC to the ECU 15 is stopped.

(E) The target drive torque T _OS is greater than or _equal to the required drive torque T _d .

(F) There is an abnormality such as a failure or disconnection in the control system for turning.

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 assembled. However, when the accelerator opening sensor 77 is detached from the throttle body 21 for inspection and maintenance of the vehicle 82 and reassembled, it is practically impossible to accurately return the accelerator opening sensor 77 to the original mounting state. This is possible, and there is also a risk that the position of the accelerator opening sensor 77 with respect to the throttle body 21 may shift due to secular change 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, which shows the procedure for learning 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 from on to off, for a fixed time, for example, 2 seconds. Accelerator opening 77
Output, the minimum value of the output of the accelerator opening sensor 77 during this period is taken in as the fully closed position of the accelerator opening θ _A , stored in the RAM with backup (not shown) built into the ECU 15, and stored next time. Until learning, the accelerator opening θ
Correct _A.

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.
If it is determined that the fully closed value θ _AC of the accelerator opening θ _A is not stored in the RAM in step, the initial value θ is set at A2.
Store _{A (O)} 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
At, it is determined whether or not the ignition key switch 75 is in the ON state. If it is determined in step A3 that the ignition key switch 75 has changed from the ON state to the OFF state, the learning timer (not shown) starts counting in A4. After the learning timer starts counting, it is determined at A5 whether the idle switch 68 is in the on state.

If it is determined in step A5 that the idle switch 68 is off, it is determined in step A6 whether or not the count of the learning timer reaches 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 at A7 and the current accelerator opening θ _{A ( It} is determined whether or not _n) is smaller than the minimum value θ _AL of the accelerator opening θ _A so 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 it is determined that the accelerator opening θ _{A (n)} of this time is smaller than the minimum value θ _AL of the accelerator opening θ _A so far, the current accelerator opening θ θ is set at A9. Update _{A (n)} as a new minimum value θ _AL . 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. When it is determined that the minimum value θ _AL of the accelerator opening θ _A is within the preset grip value range, the initial value θ _{A (O) of the} accelerator opening θ _A or all of the accelerator opening θ _A is set. A value obtained by bringing the closed value θ _AC closer to the minimum value θ _{AL by} a constant value, for example, 0.1 volt is set as the fully closed value θ _{AC (n)} of the accelerator opening θ _{A in} this learning. That is, when the initial value θ _{A (O)} or the fully closed value θ _{AC of} the accelerator opening θ _A 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 is set, and conversely, when the initial value θ _{A (O)} or the fully closed value θ _AC of the accelerator opening θ _A is larger than its minimum value θ _AL. Is set as 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
When it is determined that _AL is out of the preset clip value range, the grip value of the one out of A12 is replaced as the minimum value θ _AL of the accelerator opening θ _A , and the above A1
All closed value theta _AC accelerator opening theta _A shifts to the first step
Learning correction.

In this way, by setting the minimum value θ _AL of the accelerator θ _A and the upper limit value and the lower limit value, there is no possibility of erroneous learning even if the accelerator opening sensor 77 fails, and learning correction per time is performed. By setting the amount to a constant value, erroneous learning will not be performed even for disturbance such as noise.

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, but it is incorporated in a seat (not shown). Even if the ignition key switch 75 is turned on, the seating sensor is used to detect that the driver has left the seat by using the seat pressure change and the position variation of the seating sensor, and the learning process after step A4 is started. It may be done. Further, when it is detected that the door lock device (not shown) is operated from the outside of the vehicle 82 or the door lock device is operated by the key entry system, the fully closed value of the accelerator opening sensor 77 is detected. It is also possible to start learning θ _AC . In addition to this, the position of the shift lever (not shown) of the hydraulic automatic transmission 13 is the neutral position or the parking position (the 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 off, 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. When the driver operates the manual switch to select the turning control, the turning control described below is performed. It is designed to operate.

As shown in FIG. 33 showing the flow of control for determining the target drive torque T _OC for turning control, the target drive torque T _OC is calculated by the various data detection and arithmetic processing described above at C1. However, this operation is performed irrespective of the operation of the manual switch.

Next, at C2, it is determined whether the vehicle 82 is under turning control, that is, whether the turning control flag F _C is set. Since the turning control is not being performed at first, it is determined that the turning control flag F _C is in the reset state, and C3, for example (T _d
-2) It is determined whether or not the following. That is, the target drive torque T _OC can be calculated even when the vehicle 82 is traveling straight,
The value is usually larger than the driver's required driving torque _Td . However, since the required drive torque T _d is generally small when the vehicle 82 turns, the target drive torque T _OC
Is determined as the start condition of the turning control when the value becomes equal to or less than the threshold value (T _d -2).

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

At the step of C3, the target drive torque T _OC is the threshold value (T _d −
2) When it is determined that the following is true, the TCL 76 determines at C4 whether the idle switch 68 is off.

When it is determined in step C4 that the idle switch 68 is off, that is, the accelerator pedal 31 is depressed by the driver, the turning control flag F _C is set in C5. Next, at C6, it is determined whether or not 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. To be done.

Two rudder angle neutral position learned flag F in step C6
_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 flag F _C is set at step C7, and the previously calculated value at C8, that is, the target drive torque T _OC at step C1 is used as it is. To be 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 it is determined in step C17 that the turning control flag F _C is set,
Although the process shifts to the step of C8, since the steering angle δ calculated by the formula (2) is not _reliable , the target driving torque of the formula (8) is calculated using the corrected lateral acceleration G _YF based on the formula (5). T _OC is this
It is adopted as the calculated value in the step of C8.

When it is determined in step C17 that the turning control flag F _C is not set, the target drive torque T _OC calculated by the equation (8) is not adopted, and the TCL76 sets the target drive torque T _OC. As a result, the maximum torque of the engine 11 is output at C9, and as a result, the ECU 15 reduces the duty ratio of the torque control solenoid valves 51, 56 to the 0% side. As a result, the engine 11 changes the depression amount of the accelerator pedal 31 by the driver. The corresponding drive torque is generated.

If it is determined that the target drive torque T _OC is not equal to or less than the threshold value (T _d -2) in the step C3, the process does not shift to the swing control and shifts from the step C6 or C7 to the step C9.
The TCL76 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, 56 to the 0% side, and as a result, the engine 11 causes the accelerator pedal 31 by the driver to decrease. The drive torque is generated according to the amount of depression of.

Similarly, in the step of C4, even when it is determined that the idle switch 68 is in the ON state, that is, the accelerator pedal 31 is not depressed by the driver, the TCL76 outputs the maximum torque of the engine 11 as the target drive torque T _OC. , By which E
CU15 sets the duty ratio of torque control solenoid valves 51, 56 to 0%
As a result of lowering to the side, the engine 11 generates a drive torque according to the amount of depression of the accelerator pedal 31 by the driver and does not shift to the turning control.

If it is determined in step C2 that the turning control flag F _C has been set, the target drive torque T _OC calculated this time and the target drive torque T
_It is determined whether or not the difference ΔT from _{OC (n−1)} is larger than a preset increase / decrease allowable amount T _K. This increase / decrease allowable amount T _K is a torque change amount that does not cause an occupant to feel an acceleration / deceleration shock of the vehicle 82. For example, when it is desired to suppress the target longitudinal acceleration G _XO of the vehicle 82 to 0.1 g per second, the above (7) Using the formula Becomes

Target drive torque T calculated this time in step C10
_If it is determined that the difference ΔT between _OC and the previously calculated target drive torque T _{OC (n−1)} is not larger than the preset increase / decrease allowable amount T _{K, the} target drive torque T _OC and the last time are determined at C11. difference ΔT between the calculated target driving torque T _{OC (n-1)} determines whether larger or not than the negative decrease tolerance T _K.

Target drive torque currently calculated at C11 in Step T _OC and the target driving torque T _OC previously calculated _(n-1) difference between ΔT
[Delta] T | | is increased or decreased tolerance the absolute value of the difference but it is determined to be larger than the negative decrease tolerance T _K, the target drive currently calculated torque T _OC and the target driving torque T _OC previously calculated _(n-1) T _K
Therefore, the target drive torque T _OC calculated in the step C1 is adopted as the calculated value in the step C8.

Also, the target drive torque T calculated this time in the step C11
_If it is determined that the difference ΔT between _OC and the previously calculated target drive torque T _{OC (n-1)} is not larger than the negative increase / decrease allowable amount T _K , the target drive torque T _OC of this time is corrected by the following formula at C12. Then, this is adopted as the calculated value in the step C8.

T _OC = T _{OC (n−1)} −T _{K In other} words, the previously calculated target drive torque T _{OC (n−1)}
The amount of decrease with respect to is regulated by the increase / decrease allowable amount T _K , and the deceleration shock accompanying the reduction of the drive torque of the engine 11 is reduced.

On the other hand, the target drive torque T _OC calculated this time in the step C10 and the target drive torque T
_If it is determined that the difference ΔT from _{OC (n−1)} is greater than or equal to the permissible increase / decrease amount T _K , the current target drive torque T _OC is corrected in C13 by the following equation, and this is calculated in step C8. Adopt as a value.

T _OC = T _{OC (n−1)} + T _K That is, the target drive torque T _OC calculated this time is the same as when the drive torque is increased, even when the drive torque is increased.
And the difference Δ between the target drive torque T _{OC (n−1)} calculated last time
When T exceeds the increase / decrease allowable amount T _K , the increase amount for the previously calculated target drive torque T _{OC (n-1) is} increased / decreased allowable amount.
It is regulated by T _K to reduce the acceleration shock due to the increase in the drive torque of the engine 11.

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

Here, if the turning control flag F _C is set, the target drive torque T _OC is not larger than the drive torque T _d requested by the driver, and therefore it is determined at C15 whether or not the idle switch 68 is in the ON state. To do.

If it is determined in step C15 that the idle switch 68 is not in the ON state, it means that the turning control is required, and therefore 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.

Further, if it is determined in step C14 that the target drive torque T _OC is larger than the driver's required drive torque T _d , it means that the turning traveling of the vehicle 2 is completed.
Resets the turning control flag F _C at C16. Similarly, if it is determined in step C15 that the idle switch 68 is in the on state, the accelerator pedal 31 is not depressed, so the process proceeds to step C16 and the turning control flag F _C is reset. To do.

When the turning control flag F _C is reset at C16, the TCL76 outputs the maximum torque of the engine 11 at C9 as the target drive torque T _OC , which causes the ECU 15 to output the duty of the torque control solenoid valves 51, 56. As a result of reducing the rate to 0%,
The engine 11 generates drive torque according to the amount of depression of the accelerator pedal 31 by the driver.

In order to simplify the above-described turning control procedure, it is of course possible to ignore the driver's requested drive torque T _d , and in this case, the reference drive torque T _d that can be calculated by the equation (7) as the target drive torque. The drive torque T _B should be adopted.
Further, even when the driver's required drive torque T _d is taken into consideration as in the present embodiment, the weighting coefficient α is not set to a fixed value, but the value of the coefficient α is gradually decreased with the passage of time after the start of control. Alternatively, it may be gradually decreased according to the vehicle speed V to gradually increase the adoption ratio of the driving torque T _d requested by the driver. Similarly, the value of the coefficient α is kept constant for a while after the control is started, and is gradually decreased after a predetermined time elapses, or the value of the coefficient α is increased with an increase in the steering shaft turning amount δ _H. In particular, it is possible to drive the vehicle 82 safely in a turning circuit in which the radius of curvature becomes gradually smaller.

In the above-described embodiment, the target drive torque for the high μ road is calculated, but the target drive torques for turning control corresponding to the high μ road and the low μ road are calculated respectively, and these target drive torques are calculated. The final target drive torque may be selected from the torque. In the multiplication processing method described above,
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 when calculating the target driving torque T _OC, this regulation It may be performed for the target longitudinal acceleration G _XO .

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

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

On the other hand, in the step of M12, 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 M15 as the final target drive torque T _O , and this is output to the ECU 15.

If it is determined in step M14 that the turning control in-progress flag F is not set, the TCL76 sets the maximum torque of the engine 11 as the final target drive torque T _O in the ECU 15 in M16.
Output to.

While the final target drive torque T _O is selected as described above, the output of the engine 11 cannot be reduced even by the fully closing operation of the throttle valve 20 via the actuator 41. In the case of a sudden change to a freezing road, the TCL 76 sets a retard ratio for the basic retard amount P _B of the ignition timing P set by the ECU 15, and outputs it to the ECU 15.

The basic delay amount p _B is a maximum value of the delay angle that does not hinder the operation of the engine 11, and is set based on the intake air amount of the engine 11 and the engine speed N _E. Further, as the retardation ratio, in this embodiment, 0 level that sets the basic retardation amount p _B to 0,
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 levels, III level, are set, and basically, the retardation rate is selected such that the larger the change rate G _s of the slip amount s becomes, the larger the retardation amount becomes.

As shown in FIG. 35 showing the procedure for reading this retardation rate, the TCL76 first resets the ignition timing control flag F _P at P1 and determines whether the slip control flag F _S is set at P2. To judge. When it is determined in step P2 that the slip control flag F _S is set, the ignition timing control flag F _P is set in P3, and it is determined in P4 whether the slip amount s is less than 0 km / h. To do. If it is determined in step P2 that the slip control flag F _S is not set, the process proceeds to step P4.

In the step of P4, if the slip amount s is less than 0 km / h, that is, if it is judged that there is no problem even if the driving torque of the engine 11 is increased, the retard ratio is set to 0 level in P5, and this is output to the ECU 15. To do. On the contrary, if it is determined in step P4 that the slip amount s is 0 km / h or more, P6
When the slip amount change rate G _S is equal to or a how 2.5g, step by the slip rate of change G _s of the P6 is equal to or less than 2.5g in the late at P7 It is determined whether the angular proportion is at the III level.

Also, the slip amount change rate G _s is 2.5 g in the step of P6.
When it is determined that the front wheels 64 and 65 are suddenly slipping, the final target drive torque T _O is 4k at P8.
If the final target drive torque T is less than 4 kgm, that is, if it is determined that the drive torque of the engine 11 needs to be sharply suppressed, it is determined whether the retard angle ratio is P9. Is set to the III level and the process shifts to the step of P7. Conversely, the final target drive torque T _O is 4k in the step P8.
If it is determined to be gm or more, the process directly shifts to the step of P7.

If it is determined in the step of P7 that the retard ratio is the III level, it is determined in P10 whether the slip amount change rate G _s exceeds 0 g. Here, the slip amount change rate G _s is
When it is determined that the slip amount s exceeds 0 g, that is, the slip amount s tends to increase, the ignition timing control flag F is set at P11.
Whether or not _P is set is determined, but if it is determined in step P10 that the slip amount change rate G _s is 0 g or less, that is, the slip amount s is in a decreasing tendency, then at P12 It is determined whether or not the slip amount s exceeds 8 km / h.

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

In the step of P14, if it is determined that the slip amount change rate G _s is 0.5 g or less, that is, the change of the slip amount s is not so rapid, whether or not the retard ratio is II level is determined in P15. If it is determined in step P14 that the slip amount change rate G _s is not 0.5 g or less, then P16
Set the retard ratio to II level with and move to the step of P15.

If it is determined in step P15 that the retard ratio is at the II level, the slip amount change rate G
_If it is determined that _s exceeds 0 g, and conversely it is determined that the retard ratio is not at the II level, it is determined at P17 whether the slip amount change rate G _s is 0.3 g or less. In the step of P16, when it is determined that the slip amount change rate G _s does not exceed 0 g, that is, the slip amount s tends to decrease,
At P18, it is determined whether or not this slip amount s exceeds 8 km / h. When it is determined in step P18 that the slip amount s is 8 km / hour or less, the retard ratio is switched from II level to I level in P19, and the process proceeds to step P17. Further, when it is judged in the step P16 that the slip amount change rate G _s is 0 g or more, that is, the slip amount s tends to increase, and in the step P18, the slip amount s exceeds 8 km / h. That is, when it is determined that the slip amount s is large, the process proceeds to 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. On the contrary, if it is judged in the step of P17 that the slip amount change rate G _s exceeds 0.3 g, that is, the slip amount s tends to increase at all, the retard ratio is set to the I level in P21. Set to.

If it is determined at P20 that the retard ratio is at the I level, it is determined at P22 whether the slip amount change rate G _s exceeds 0 g, and this is 0 g or less, that is, the slip amount. When s is determined to be decreasing, it is determined in P23 whether the slip amount 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, the front wheels 64 and 65 are hardly slipping, the retard ratio is set to 0 level in P24, and this is set in the ECU 15. Output. Further, when it is determined in step P20 that the retardation ratio is not at the I level, or in step P22, it is determined that the slip amount change rate G _s exceeds 0 g, that is, the slip amount s tends to increase. If the slip amount s is 5 km / h or more in step P23, that is, if the slip amount s is relatively large, the process proceeds to step P11.

On the other hand, in the step of P11, the ignition timing control flag F
_If it is determined that _P is set, it is determined at P25 whether or not the final target drive torque T _O is less than 10 kgm.
When it is determined in step P11 that the ignition timing control flag F _P is not set, the retard ratio is set to 0 level in P26, and then the process proceeds to step P25.

Then, in P25, if it is determined that the final target drive torque T _O is 10 kgm or more, that is, if the engine 11 is generating a slightly larger drive force, the retard ratio is II level in P27. If it is determined that this retardation rate is at the II level, the retardation rate is reduced to the I level at P28, and this is output to the ECU 15.

In the step of P25, the final target drive torque T _O 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. Then, if it is determined that the hydraulic automatic transmission 13 is in the process of shifting, it is determined in P30 whether or not the retard ratio is the III level, and in this P30 step, the retard ratio is the III level. If it is determined that the delay ratio is II level in P31, it is output to the ECU15. 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 directly output to the ECU 15.

For example, if the retardation rate of level III is set in the step of P9, the slip amount change rate G _s exceeds 0 g and the slip amount s exceeds 5 km / h, that is, the increase rate of the slip amount s. Is abrupt and the final target drive torque T _O
Is less than 10 kgm and the front wheel 6
When it is determined that it is difficult to sufficiently suppress the slip of 4,65, the retard level of the III level is selected and the opening of the throttle valve 20 is forcibly closed to prevent the occurrence of slip. We are trying to efficiently control it in the initial 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
The ignition timing P and the basic retardation amount p _B are read out from a map (not shown) regarding p _{B based} on the detection signal from the crank angle sensor 62 and the detection signal from the air flow sensor 70, and the timing is sent from the TCL 76. The target retard angle p _O is calculated by making a correction based on the ratio. in this case,
The upper limit value of the target retardation amount p _O is set corresponding to the upper limit temperature of the exhaust gas that does not damage the exhaust gas purifying catalyst (not shown), and the temperature of this exhaust gas is determined by the detection signal from the exhaust temperature sensor 74. To be detected.

When 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 retarding the ignition may cause knocking or stall of the engine 11, the ignition retarding operation of the ignition timing P described below 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, when it is determined that the retard ratio is the III level in the step of Q2, the basic retard amount p _B read from the map in Q3 is used as it is as the target retard amount p _O ,
The ignition timing P is retarded by the target retardation amount p _O. Furthermore, the duty ratio of the torque control solenoid valves 51, 56 is set to 100% in Q4 so that the throttle valve 20 is fully closed regardless of the value of the final target drive torque T _O , and the throttle valve is forcibly throttled. Valve 20
Realize the fully closed state of.

When 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 at the II level. And when it is judged that the retard ratio is II level in the step of this Q5,
Using base retardation amount p _B read the target retard amount p _O map in step as well as Q6 of the Q3 as it target retard amount p _O, the ignition timing P target retard amount p _O only Delay.
Further, in Q7, the ECU 15 sets the duty ratio of the torque control solenoid valves 51, 56 in Q7 according to the value of the target drive torque T _OS , regardless of the amount of depression of the accelerator pedal 31 by the driver. 11 Drive torque is reduced.

Here, the ECU 15 stores a map for obtaining the throttle opening θ _T using the engine speed N _E and the driving torque of the engine 11 as parameters, and the ECU 15 uses this map to calculate the current engine speed N _E and The target throttle opening θ _TO corresponding to this target drive torque T _OS is read.

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 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 of 51, 56 is reduced to 0%, and the engine 11 is caused to generate a drive torque corresponding to the amount of depression of the accelerator pedal 31 by the driver.

When it is determined in the step Q5 that the retard ratio is not at the II level, it is determined at Q8 whether the retard ratio is set at the I level. If it is judged in the step of Q8 that the retard ratio is set to I level,
The target retardation amount p _O is set according to 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, when it is judged in the step of Q8 that the retard ratio is not at the I level, it is judged in Q10 whether the target retard amount p _O is 0, and it is judged that it is 0. In this case, the process proceeds to step Q7, where the ignition timing P is not retarded, and the torque control solenoid valves 51, 56 are set according to the value of the target drive torque T _OS.
Set the duty ratio of the
The drive torque of the engine 11 is reduced regardless of the depression amount of.

If it is determined in step Q10 that the target retardation amount p _O is not 0, the target retardation amount p _O is set to, for example, 1 by the ramp control at the sampling period Δt of the main timer in Q11.
After subtracting each time until p _O = 0, the shock due to the fluctuation of the driving torque of the engine 11 is reduced, and then the process shifts to the step of Q7.

Note that the slip control flag F _S
If it is determined that the engine has been reset, the normal running control that does not reduce the drive 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 ratio of the valves 51 and 56 to 0%, the engine 11 generates a drive torque according to the depression amount of the access pedal 31 by the driver.

<Effects of the Invention> As described in detail with reference to the embodiments, according to the present invention, after the steering axis neutral unknown learning correction is executed, if the driver turns the steering wheel at a certain vehicle speed, the vehicle is The target lateral acceleration is calculated based on the vehicle speed and reliable steering angle information at the same time when the steering wheel is turned, so that the target driving torque corresponding to the target lateral acceleration is obtained. By controlling the drive torque of the engine, the responsiveness of the turning control and the accuracy of the turning control can be significantly improved. Further, according to the present invention, the turning control is executed based on the lateral acceleration actually acting on the vehicle until the learning correction of the steering shaft neutral position is executed. Therefore, the turning control is executed whenever necessary. be able to. That is, in the case where the vehicle starts from the middle of a meandering mountain road and travels on the mountain road, the learning correction cannot be executed as a result of the predetermined straight traveling condition of the vehicle not being satisfied, and the turning control should be executed. It will be especially useful for

[Brief description of drawings]

FIG. 1 is a conceptual diagram when a vehicle output control device that realizes the embodiment method of the present invention is applied to a front-wheel drive type vehicle incorporating a hydraulic automatic transmission having four forward gears and one reverse gear, and FIG. Is a schematic configuration diagram thereof, FIG. 3 is a sectional view showing the drive mechanism of the throttle valve, FIG. 4 is a flow chart showing the overall flow of the control, and FIG. 5 shows the flow of neutral position learning correction of the steering shaft. FIG. 6 is a flowchart, FIG. 6 is a map showing the relationship between vehicle speed and variable threshold value, FIG. 7 is a graph showing an example of the correction amount when the neutral position of the steering shaft is learned and corrected, and FIG. 8 is the target drive for slip control. FIG. 9 is a block diagram showing the torque calculation procedure, and 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 vehicle speed and running resistance, and FIG. 11 is a map showing the relationship between steering shaft turning amount and correction torque.
Figure 12 is a map that regulates the lower limit of the target drive torque immediately after the start of slip control, Figure 13 is a graph showing the relationship between the coefficient of friction between the tire and the road surface, and the slip ratio of this tire, and Figure 14 is the target lateral value. A map showing the relationship between acceleration and the speed correction amount associated with acceleration, FIG. 15 is a map showing the relationship between lateral acceleration and the speed correction amount associated with turning, and FIG. 16 is a circuit for detecting an abnormality in the steering angle sensor. Figures and 17 show steering angle sensor 84
18 is a flowchart showing the flow of the abnormality detection processing, 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 procedure for selecting the lateral acceleration, and FIG. 20 is the slip amount and the proportional coefficient. 21 is a map showing the relationship between the vehicle speed and the lower limit of integral correction torque, and FIG.
Fig. 22 is a graph showing the increase / decrease region of the integral correction torque, Fig. 23 is a map showing the relationship between each shift speed of the hydraulic automatic transmission and the correction coefficient corresponding to each correction torque, and Fig. 24 is the engine speed and A map showing the relationship between the required drive torque and the accelerator opening, FIG. 25 is a flowchart showing the flow of slip control, FIG. 26 is a block diagram showing the procedure for calculating the target drive torque for turning control, and FIG. 27 is A map showing the relationship between the vehicle speed and the correction coefficient, and FIG. 28 is a graph showing the relationship between the lateral acceleration and the steering angle ratio for explaining the stability factor.
Figure 29 is a map showing the relationship between the target lateral acceleration, target longitudinal acceleration and vehicle speed, Figure 30 is a map showing the relationship between lateral acceleration and road load torque, and Figure 31 is the learning of the fully closed position of the accelerator opening sensor. A graph showing an example of the correction procedure, FIG. 32 is a flow chart showing another example of the flow of learning correction of the fully closed position of the accelerator opening sensor, FIG. 33 is a flow chart showing the flow of turning control, and FIG. 34 is FIG. 35 is a flow chart showing the flow of final target torque selection operation, FIG. 35 is a flow chart showing the flow of delay angle selection operation, and FIG. 36 is a flow chart showing the procedure of engine output control. In the figure, reference numeral 11 is an engine, 13 is 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. A rod, 47 is a connecting 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 and 65 are front wheels, 66 is a front wheel rotation sensor, 67 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, and 76 is a TC.
L and 77 are accelerator opening sensors, 78 and 79 are rear wheels, 80 and 81 are rear wheel rotation sensors, 82 is a vehicle, 83 is a steering axis, 84 is a steering angle sensor, 85 is a steering wheel, and 86 is a steering axis reference. Position sensor, 87
Is a communication cable, 104, 105, 117, 135 are multiplying sections, 106, 131 are differential calculating sections, 107, 110 are clipping sections, 108, 123 are filter sections, 109 is a torque converting section, 111 is a running resistance calculating section, 112, 11
4, 119 is an addition unit, 113 is a cornering drag correction amount calculation unit, 115 is a variable clip unit, 116, 121 and 124 are subtraction units, 118
Is an acceleration correction unit, 120 is a turning correction unit, 122 is a lateral acceleration calculation unit, 143 is a switch, A is a stability factor, b is a tread, F _P is an ignition timing control flag, and F _S is a slip control flag. , G _F is the actual front wheel acceleration, G _KC , G _KF is the front wheel acceleration correction amount, G _s is the slip amount change rate, G _XF is the corrected longitudinal acceleration, G _O is the target longitudinal acceleration, G _YO is the target lateral acceleration,
g is the gravitational acceleration, N _E is the engine speed, P is the ignition timing, p _B is the basic retardation amount, p _O is the target retardation amount, r is the wheel effective radius, S _O is the target slip ratio, and s is the slip amount. , T _B is the standard 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 _OC is the target drive torque for turning control, T _OS is the target drive torque for slip control, T _P is the proportional correction torque, T _PID is the final correction torque, T _R is the running resistance, Δ
t is the sampling period, V is the vehicle speed, V _F is the actual front wheel speed, V _FO ,
V _FS is the target front wheel speed, V _K and V _KC are slip correction amounts, V _RL is the left rear wheel speed, V _RR is the right rear wheel speed, V _S is the vehicle speed for slip control, W _b
Body weight, [delta] is a front wheel steering angle, [delta] _H is the turning angle of the steering shaft,
ρ _d is an operating gear reduction ratio, ρ _KI is an integral correction coefficient, ρ _KP is a comparison correction coefficient, ρ _m is a gear ratio of a hydraulic automatic transmission, and ρ _T is a torque converter ratio.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Miyata 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) References JP-A-62-10437 (JP, A) Special features Kai 62-153533 (JP, A) JP-A-2-70937 (JP, A)

Claims (1)

(57) [Claims] 1. A torque reducing means capable of reducing a drive torque of an engine independently of an operation by a driver, and a target drive torque of the engine in accordance with a lateral acceleration which is a lateral acceleration generated in a turning vehicle. In a vehicle output control device having a turning control unit that sets and controls the operation of the torque reducing means so that the driving torque of the engine becomes the target driving torque, the straight traveling state of the vehicle is detected by learning, With the steering shaft in this straight traveling state as the steering shaft neutral position, the target lateral acceleration calculating means for calculating the target lateral acceleration based on the steering angle with respect to the steering shaft neutral position and the vehicle speed, and the lateral acceleration actually acting on the vehicle are The lateral acceleration detecting means for detecting, and the turning control unit controls turning based on an actual lateral acceleration until the steering axis neutral position of the vehicle is detected. And a switch means for selecting an amount based on the target lateral acceleration as a lateral acceleration for the turning control unit to perform turning control after detecting the steering shaft neutral position. The output control device of the vehicle.