JPH115461A - Device and method for controlling automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of torque fluctuation uncomfortable to a driver by controlling so as to restrict the fluctuation of any one of the driving shaft torque, driving force and acceleration in the case where a deviation is generated between a target value, which a driver aimed, and a real target value at the time of switching the control mode to the following control. SOLUTION: In case of changing the target value of the driving shaft torque from a first value to a second value at the (a) time in the condition that the acceleration pedal operated variable α is larger than 0, namely, in the accelerating condition, and in the case where the target car speed Vt or the target car speed Vtt is remarkably larger than the real car speed N0 , a deviation Δk between the first target value Ttar1 and the second target value Ttar2 becomes large. At this stage, the target value Ttar is gradually increased to the (b) time after the predetermined time Ts is passed through and the second target value Ttar2 is not used till the second target value Ttar2 and the target value Ttar achieve the predetermined value k1, at which the torque fluctuation is not generated. With this method, fluctuation of the real wheel torque generated after the (a) time is restricted, and the target value is smoothly changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus and a control method for a motor vehicle, and more particularly, to an output of a power train including an engine and a transmission according to a recognition result of a vehicle traveling ahead and a driving intention of a driver. The present invention relates to a control device and a control method for controlling.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 7-47862 discloses a prior art in which the driving state of a vehicle can be changed according to the driving state of a preceding vehicle or a driver's intention. . This publication describes a method of selecting whether to drive the vehicle according to the running state of the vehicle in front or to drive the vehicle according to the driver's intention by an operation of the driver himself and switching the respective driving. ing. That is, the switching between the two traveling states is left to the driver's own judgment, and the vehicle can travel with the driving force intended by the driver.

[0003]

It is important to establish a technique for detecting the distance and the relative speed between the host vehicle and a preceding vehicle (including obstacles) using a radar to ensure the safety of the host vehicle. It has become to. In the above-described conventional technology, it is indispensable to achieve both a driving state intended by a driver (a linear acceleration sensation corresponding to an accelerator pedal depression amount) and safety (collision prevention).

However, in the existing control method of the running state of the vehicle, since the driver's intention is always set to the highest priority, the running state of the vehicle in front and the safety of the own vehicle are taken into consideration. It is technically difficult to automatically switch between the state and the state, and this switching depends on the operation of the driver. As a result, if the difference between the two calculated values at the time of switching between the two running states is large, a sudden change in torque occurs, and the occurrence of acceleration / deceleration fluctuations unexpected by the driver cannot be avoided.

[0005] For example, in the above-mentioned conventional technique, when the driver switches from a state in which the accelerator pedal is depressed to a small amount to a traveling state according to the traveling state of the preceding vehicle, that is, to a control for following the preceding vehicle, the driver receives There has been a problem that a deviation occurs between the intended target value and the actual control target value by the follow-up control, and a torque fluctuation that the driver feels uncomfortable occurs.

According to the present invention, switching between a control amount for ensuring vehicle safety and a control amount for achieving a state intended by a driver can be executed while reducing shock from a power train. It is an object of the present invention to provide a control device and a control method for a vehicle that can achieve both safety and drivability.

[0007]

SUMMARY OF THE INVENTION The present invention provides a first target value before change as a target value of at least one of control of a drive shaft torque, a driving force, and acceleration / deceleration, and a driving mode or a driving mode intended by a driver. When a deviation exceeding a predetermined value occurs between the second target value and the second target value calculated in accordance with the forward traveling environment, at least any one of the drive shaft torque, the driving force, and the acceleration / deceleration is suppressed. The present invention provides a control device for an automobile that performs the control as described above.

Preferably, in a control apparatus for a vehicle, a target value of a drive shaft torque on a transmission output shaft side is set based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target value. Driving mode setting means for setting a driving mode intended by the user, or environment recognizing means for recognizing a forward driving environment, and target value changing means for changing the target value in accordance with a signal obtained by one of the two means. And when changing the target value,
When a deviation of a certain value or more occurs between the first target value before the change and the second target value calculated based on the signal, a torque fluctuation suppressing unit that controls the fluctuation of the drive shaft torque is provided. .

Preferably, the signal used for calculating the target value of the drive shaft torque includes a means for detecting the actual acceleration / deceleration of the vehicle and a means for detecting the actual vehicle speed of the vehicle in addition to the accelerator pedal depression amount. Prepare.

[0010] Preferably, when the target value is changed by the changing means, the torque fluctuation suppressing means changes the first target value before change as an initial value at a fixed rate for a predetermined period of time. When the deviation between the value and the second target value decreases to a predetermined value, the value is changed to the second target value.

Preferably, the torque fluctuation suppressing means switches instantaneously when switching from the second target value to the first target value when the target value is changed by the changing means.

Preferably, the signal obtained by either the driving mode setting means or the environment recognizing means is an inter-vehicle distance to a preceding vehicle and a relative speed.

Preferably, a target value of the drive shaft torque on the transmission output shaft side is set based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and at least the engine torque and the gear ratio are set in accordance with the target value. In a control device for a motor vehicle to be controlled, a target rotation speed calculating means for calculating a target value of a transmission input rotation speed according to the target value, and a target rotation speed limit setting means for limiting the transmission input rotation speed. Is provided.

Preferably, a target value of the drive shaft torque on the transmission output shaft side is set based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and at least the engine torque and the gear ratio are set according to the target value. In a control device for an automobile to be controlled, target speed ratio calculating means for calculating a target value of the speed ratio in accordance with the target value, and target speed ratio limit setting means for limiting the speed ratio are provided. .

Preferably, at least one of the drive shaft torque, the driving force, and the acceleration / deceleration of the transmission output shaft is set as a target value based on at least the accelerator pedal depression amount, and at least the engine torque is set according to the target value. In a control device for a vehicle to be controlled, a running load calculating unit for calculating a running load of the vehicle, a deceleration calculating unit for calculating an actual deceleration of the vehicle, and a deceleration calculated by at least the deceleration calculating unit. And a target deceleration calculating means for calculating a target deceleration based on the accelerator pedal depression amount, wherein the running load calculated by the running load calculating means and the target deceleration calculated by the target deceleration calculating means are provided. There is provided a target value calculating means for calculating the target value according to the speed.

[0016] Preferably, the running load calculating means is a weight rewriting means capable of rewriting the calculated magnitude of the running load.

With the above means, the above-mentioned problem can be solved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment) An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a control block diagram of one embodiment of the present invention. First, a general driver operates an accelerator pedal (not shown) to drive an automobile (not shown).
The control logic for driving the vehicle will be described.

Accelerator pedal depression amount α and vehicle speed No
Is input to the first target drive shaft torque calculating means 1 and the first target value Ttar1 is calculated and input to the target value changing means 2. The changing means 2 outputs a first target value Ttar1.
Is substituted for the target value Ttar as it is, and the target value Ttar
Is directly input to the target brake force calculating means 3, the target engine torque calculating means 4, and the target gear ratio calculating means 5.

In the calculating means 3, the target value T shown in FIG.
A brake control area consisting of tar and the target transmission input shaft rotation speed is searched to calculate a target braking force Bt. This target braking force Bt is input to the brake actuator 6, and the brake control is executed.

The target speed ratio calculating means 5 calculates a target speed ratio It using the target value Ttar and the vehicle speed No as parameters during acceleration. Further, at the time of deceleration, an engine brake control range composed of the target value Ttar and the target transmission input shaft side rotation speed shown in FIG. 8 is searched, and the target gear ratio It is calculated. The target speed ratio It is input to the speed change actuator 7, and acceleration control and engine brake control are executed.

Further, the target engine torque calculating means 4 calculates a target engine torque Tet from the target value Ttar and the target gear ratio It, and inputs the calculated target engine torque Tet to the target throttle opening calculating means 8. Then, the target throttle opening θt is calculated and output to the throttle actuator 9.
At this time, the followability of the actual drive shaft torque to the target value Ttar is improved by using the actual speed ratio Ir, which is the ratio between the input shaft speed Nt of the transmission and the vehicle speed No, instead of the target speed ratio It. , Good torque control becomes possible.

Similar results can be obtained by using vehicle longitudinal acceleration or driving force instead of the driving shaft torque. Further, in the present embodiment, the brake control is used. However, it is possible to execute better acceleration / deceleration control than the conventional vehicle only by controlling the engine torque and the gear ratio, and it is possible to perform the driving intended by the driver. Become.

Although the above description has been directed to a vehicle equipped with an engine that injects fuel into an intake port, an engine that injects fuel into a combustion cylinder can increase the air-fuel ratio. Therefore, by adopting the air-fuel ratio control in which the throttle control and the fuel amount control are combined, it is possible to perform the drive shaft torque control with higher accuracy.

Next, a description will be given of a control logic in a case where the driver requests a constant vehicle speed control or a constant inter-vehicle distance control in place of the normal traveling by using the driving mode change switch SW or the like.

In FIG. 1, when constant vehicle speed control is requested, the target vehicle speed Vt and the vehicle speed No are input to the second target drive shaft torque calculating means 10, and the deviation between the target vehicle speed Vt and the vehicle speed No and the target vehicle speed Vt are calculated. The target acceleration / deceleration is obtained from the time required until the second target value is reached, and the second target value Ttar2 is calculated using the vehicle weight, the tire radius, the gravitational acceleration, and the running resistance on level ground. Then, the second target value Ttar2 is input to the limiter setting means 11, and as shown in FIG. 4, if the second target value Ttar2 exceeds the target limit drive shaft torque Ttar2 ', the limit drive shaft The torque is limited to Ttar2 '. As a result, sudden acceleration during traveling at a constant vehicle speed can be avoided, and acceleration control without a sense of incongruity for the driver becomes possible. Then, instead of the first target value Ttar1 during normal traveling, the limit drive shaft torque Ttar2 'or the second target value Tt is used.
Actuator 6, using the value of ar2 itself as the target value
Driving the vehicle by driving 7,9.

The change of the target value is performed by the change switch S
It is executed by the signal of W. Alternatively, when the inter-vehicle distance St becomes considerably small and it is determined that there is a danger, a logic for automatically changing the target value is included. That is, the traveling environment ahead is recognized by a radar, a camera, or the like, and the result of the recognition is input to the target value changing means 2, and the first target value Ttar is input.
The target value of the drive shaft torque is automatically changed from 1 to the second target value Ttar2.

Next, when constant inter-vehicle distance control is requested, the relative speed Vs with respect to the preceding vehicle, the inter-vehicle distance St, the target inter-vehicle distance Stt, and the vehicle speed No are input to the second target drive shaft torque calculating means 10, The target acceleration / deceleration is obtained from the deviation between the target vehicle speed Vtt and the vehicle speed No obtained from the relative speed Vs with the preceding vehicle, the inter-vehicle distance St, and the target inter-vehicle distance Stt, and the time to the target vehicle speed. A second target value Ttar2 is calculated using the acceleration and the flat road running resistance. Thereafter, control similar to the above-described constant vehicle speed control is executed.

The method of changing the first target value Ttar1 and the second target value Ttar2 will be described with reference to FIGS.

FIG. 3 is a time chart when the target value is changed from the first to the second, and FIG. 4 is a time chart when the target value is changed from the second to the first. FIG.
Let us consider a case where the target value of the drive shaft torque is changed from the first value to the second value at the time point a, for example, when α is larger than 0, that is, when the vehicle is accelerating. At time a, the second target value T
tar2 is calculated and the target value is changed from the first target value Ttar1 to the second target value Ttar2, but if the target vehicle speed Vt
Alternatively, when the target vehicle speed Vtt is considerably higher than the current vehicle speed No, the first target value Ttar1 and the second target value Tta
The deviation Δk of r2 increases. Therefore, if the target value is changed immediately at the time a, the actual wheel torque fluctuates (conventionally) and the ride quality deteriorates.

On the other hand, according to the present invention, when the target value is changed from the first target value Ttar1 to the second target value Ttar2 at the time a, the predetermined time Ts has passed in the target value changing means 2 for b. Until the timing, the target value Ttar is gradually increased, and the second target value Ttar2 and the target value Ttar are not used until the target value Ttar reaches the predetermined value k1 at which no torque fluctuation occurs. Thereby, the fluctuation of the actual wheel torque generated after the timing a can be suppressed, and the target value can be smoothly changed.
That is, it is possible to make a transition to the constant vehicle speed control and the constant inter-vehicle distance control without a sense of incongruity.

Next, in FIG. 4, when the accelerator pedal depression amount α is larger than 0, that is, when the vehicle is accelerating, the target value of the drive shaft torque is changed from the second target value Ttar2 to the first target value Ttar1. Consider the case of changing at time c. In period c, the accelerator pedal depression amount α and the vehicle speed N
The first target value Ttar1 is calculated from o, and the target value is changed from the second target value Ttar2 to the first target value Ttar1. In this case, the driver's intention to accelerate is emphasized. Change the target value. In addition, a time constant that does not deteriorate the feeling of acceleration, that is, about 200 milliseconds or less may be provided.

FIG. 2 is a system configuration diagram of the present invention. An engine 16 and a transmission 17 are mounted on the vehicle body 15, and drive horsepower transmitted to a power train from the engine 16 to the wheels 18 is controlled by an engine power train control unit 19. In the engine power train control unit 19, a first target value Ttar1 (or driving force, acceleration / deceleration) of the drive shaft torque is calculated, and a target throttle opening θt (or air) is calculated according to the calculated target value. Flow rate), fuel amount, ignition timing, brake pressure Bt, gear ratio It, and transmission control hydraulic pressure PL are calculated. Fuel control includes the current mainstream intake port injection system,
Alternatively, an in-cylinder injection method with good controllability is used.

The vehicle body 15 is equipped with a television camera 20 for detecting an external situation and an antenna 21 for detecting infrastructure information. The image of the television camera 20 is input to the image processing unit 22 and image-processed to recognize a road gradient, a corner radius of curvature, traffic light information, a road sign, traffic regulation, other vehicles, pedestrians, obstacles, and the like. The recognized traveling environment signal is input to the environment-friendly power train control unit 23.

A radar system 24 of the FM-CW system or the like is installed in front of the vehicle body 15 to detect a distance St and a relative speed Vs to a vehicle or an object ahead. The antenna 21 is connected to the infrastructure information terminal device 25, and based on the infrastructure information, the road surface conditions in front (wet, dry, puddle depth, snow condition, freezing, presence of gravel and sand, etc.), weather Information (rainfall, snowfall, etc.), traffic congestion information, and the like are detected. Further, a friction coefficient μ between the tire and the road surface of the road is calculated based on the road surface condition, and input to the control unit 23.

The driving environment can also be determined from map information stored in the CD-ROM 26 or the like, and road conditions ahead (gradient, corner radius of curvature, traffic regulation, etc.) can be detected.

In the control unit 23, based on the signals such as the road gradient, the corner radius of curvature, the inter-vehicle distance St, the relative speed Vs, the friction coefficient μ, and the like, the drive shaft torque of the power train corresponding to the driving environment to be encountered in the future will be described. Second target value Tta
r2 (or driving force, acceleration / deceleration) is calculated and input to the control unit 19.

In the control unit 19, the first target value Ttar1 is obtained by the signal of the change switch SW operated by the driver.
And the second target value Ttar2 are selected. If the second target value Ttar2 is selected, the throttle opening degree θt, the fuel amount, the ignition timing, the transmission control hydraulic pressure PL, and the gear ratio are determined based on this value, that is, the target drive shaft torque corresponding to the traveling environment. It and the braking force Bt are calculated. Further, the control unit 19 receives an accelerator pedal depression amount α, a vehicle speed No, an engine speed Ne, a switch signal Msw (described later), an acceleration sensor signal Gd, a steering wheel steering angle Sa, and the like.

FIG. 5 is a control block diagram of another embodiment. However, the power train control unit serving as a base is the same as that in FIG. The difference is the engine brake control.
5, the engine brake control is executed by the gear ratio control. On the other hand, in FIG.
0 and emblem (engine brake) actuator 3
1 is provided. That is, the one-way clutch of the stepped transmission and the clutch for turning on and off the function of the one-way clutch control whether or not the reverse driving force from the tire generated on a downhill or the like is transmitted to the engine. With such a system, smooth deceleration control can be realized.

6 shows a time chart when the target deceleration control shown in FIGS. 6 and 5 is executed. First, the accelerator pedal depression amount α and the vehicle speed No, or the accelerator pedal depression amount α, the vehicle speed No, and the actual deceleration Gd of the vehicle (FIG. 1)
0), a target drive shaft torque Ttar having a negative value is calculated. Alternatively, the target value Ttar of the drive shaft torque is set by the second target value Ttar2 of the drive shaft torque from the environment-friendly powertrain control unit 23. In the case of a large deceleration control that requires brake control according to this target value Ttar (period e-
During the period f), the target engine torque Tet is set to approximately 0, that is, near the minimum value, so that the drive shaft torque becomes the target value Ttar, and the target gear ratio It is set according to the value of the target engine torque Tet. However, during the period of ef, it is necessary to turn off the engine brake control signal Eb in order to prevent deteriorating feeling of deceleration due to interference between the brake control and the engine brake control of the speed ratio control. This allows
Since the deceleration control is only the brake control, controllability and drivability during deceleration are improved.

Further, since the speed ratio shifts to the Low side (the side where the value of the speed ratio is large) at the time of deceleration, the feeling of acceleration when the accelerator pedal is depressed again is improved.

Next, a method of controlling switching from deceleration to acceleration will be described with reference to FIGS. 5 and 7 taking cornering control as an example. FIG. 7 is a time chart of the deceleration-acceleration switching control.

In the acceleration / deceleration change judging means 32 shown in FIG. 5, the accelerator pedal depressing amount α, ie, the driving shaft torque, is changed from the state where the accelerator pedal depressing amount α is 0, the target value Ttar of the drive shaft torque and the target engine torque Tet are negative. It is determined whether or not the target value Ttar has become positive. When the target value Ttar of the drive shaft torque is positive and it is determined that the vehicle is accelerating, the speed ratio change limiting means 33 holds the current speed ratio or limits the range of change. Therefore, during deceleration, the gear ratio is on the Low side (the gear ratio value is larger).
, The engine speed during acceleration increases rapidly (not shown), and the acceleration feeling is improved.

Further, in FIG. 7, the period Tl1 for holding the gear ratio or limiting the change width corresponds to the target value T of the drive shaft torque.
It is determined by the size of tar. If the target value Ttar of the drive shaft torque is large, it means that a large acceleration is required, so that the holding or limiting period needs to be increased. When the steering angle Sa changes during the period T11, that is, when it is determined that the vehicle is cornering, the steering angle Sa is set to 0 (that is, straight running).
The above-mentioned holding or control period is extended until the state returns to (the state in which the period T12 has elapsed). Furthermore, when cornering continues, extension to the period T13 is also conceivable. Also,
The determination as to whether or not the vehicle is at a corner is made based on the road curvature radius R (calculated by the road curvature radius estimating means 34), the lateral acceleration sensor, the yaw rate sensor, the infrastructure information, the navigation information, and the like, other than the steering wheel angle Sa. Can also be detected and determined. Here, in the present embodiment, the limit value of the speed ratio width is set within ± 0.5 as a range that does not affect the feeling of acceleration.

Next, a method of setting the gear ratio at the time of the target deceleration control will be described. In the case of acceleration, a conventional gear ratio map or a gear ratio in consideration of fuel efficiency can be applied, but in the case of deceleration, setting of the gear ratio is difficult because engine braking is required. Conventionally, the operating range in which the automatic transmission does not operate as intended by the driver has been on the deceleration side. In the present invention, this problem is solved using the contents of FIG. 5 and the following description of FIG.

FIG. 8 is a characteristic diagram schematically showing the speed ratio control during deceleration. In FIG. 8, the horizontal axis is the target transmission input shaft side rotational speed (this is the target speed ratio It when the vehicle speed No is constant), and the vertical axis is the target value Ttar of the drive shaft torque having a negative value (that is, the target value Ttar). It shows the target deceleration).

The area indicated by the horizontal line is a brake control area, and the area indicated by the hatched area is a speed ratio control area including engine brake control. In the case of a continuously variable transmission, the control can be set arbitrarily in all the shaded areas, but in the case of a stepped transmission (for example, a transmission having a forward four-speed gear ratio), a solid line also appears in the shaded area Only the part above can be set.

First, the continuously variable transmission will be described. For example, when the target value Ttar of the drive shaft torque is set to the value of the point A in the figure, it is possible to select all the gear ratios on the solid line from the point B to the point C in the hatched portion. . Therefore,
In order to determine a target gear ratio from among the innumerable gear ratios, it is necessary to use some conditions. For example, the driver's intention to decelerate, safety, fuel economy and the like can be cited. Here, the target limit engine speed is applied as a parameter for satisfying these conditions. For example, by setting the target limit engine speed Nlmt to the value of the point D, the target transmission input shaft side speed at the point D, that is, the target gear ratio is determined.

Next, the stepped transmission will be described. In this case, when the target value Ttar of the drive shaft torque is set to the value of the point A, the first gear or the first gear that intersects with the value of the point A among the speed ratios represented by the four thin solid lines in the hatched portion. Only the gear ratio of the second speed is selected. However, if the target limit engine speed Nlmt is set to the value of the point D as described above, it is impossible to select the second speed that is larger than the value of the point D, and the first speed is inevitably selected. In this state, the deceleration at the point E is obtained, and the target deceleration cannot be obtained. Therefore, the engine torque is increased and set to the point D of the target value. The engine torque is increased by increasing the throttle opening or increasing the fuel amount.

As described above, the negative gear ratio is set to the target value Ttar of the drive shaft torque and the limit engine speed Nlmt.
, It is possible to solve the problem of the driving range on the deceleration side where the conventional automatic transmission does not operate as intended by the driver. The target limit engine speed Nlmt is set in the speed ratio limiting means 35 based on the signal of the manual limit speed setting switch Msw shown in FIG. The target speed ratio calculating means 5 calculates and outputs the target speed ratio It based on the target value Ttar of the drive shaft torque, the target limit engine speed Nlmt, and the characteristics of FIG. 8 stored in a memory or the like (not shown). You.

FIG. 9 is a perspective view of the shift lever 40 for explaining the outline of the method of setting the manual limit speed set by the manual limit speed setting switch Msw of FIG.

By operating the shift lever 40, an economy mode (EM: Economy Mode), a normal drive mode (NDM: Normal Drive Mode), and a sport mode (SM: Sport Mode) can be selected. In the NDM, the limit engine speed for engine braking is set to a constant value of a low value of about 1500 rpm so that a large deceleration cannot be obtained. In the ED, since the fuel efficiency is more important than the feeling of acceleration, the gear ratio is set in consideration of the fuel efficiency. In the case of deceleration, the engine braking range is expanded as much as possible while satisfying the target deceleration, and fuel supply is interrupted to reduce fuel consumption. On the other hand, in the SM, the target limit engine speed Nlmt shown in FIG. 8 can be set by the driver's operation. In other words, by operating the shift lever 40 several times to the position of High in FIG. 9, the target limit engine speed Nlmt becomes large, and becomes small at the position of Low.
Is detected by The signal of the manual limit speed setting switch Msw is transmitted to the engine power train control unit 1
9 and the target limit engine speed Nlmt is set by the speed ratio limiting means 35. Further, the target limit engine speed Nlmt is output from the engine power train control unit 19 to the display means 41, for example, Sport Mode, Limit.
er Rev4000rpm is displayed to inform the driver of the current operation mode. Further, when the second target value Ttar2 is used as the target value of the drive shaft torque, acceleration / deceleration control with an emphasis on safety is executed in any mode state.

FIG. 10 is a time chart of the target deceleration control when the actual deceleration Gd is used. It is determined that the accelerator pedal depression amount α has become 0 or less, the signal of the actual deceleration Gd is detected for an arbitrary time (period gh), and the target deceleration is calculated. That is, since the change in the deceleration Gd is later than the change in the accelerator pedal depression amount α, it is necessary to provide a period of an arbitrary length for determining the target deceleration. For example, during this determination period, the brake depression force β
Is increased, the deceleration Gd at that time is set as the target deceleration. As a result, the actual power train control start time is the time point h.

However, if the determination period is too long, there is a problem in the driver's intention and safety. If the determination period is too short, it is difficult to determine the deceleration intended by the driver. It is appropriate to set between milliseconds and 800 milliseconds.

In the case of the stepped transmission, after the start of the control, based on the gear ratio control described with reference to FIG. 8, from the fourth gear to the third gear when the brake is not depressed, and from the fourth gear to the second gear when the brake is applied. , The target speed ratio It is set. The opening control of the target throttle opening θt at the time of shifting is control for improving shift response, and will be described in detail below with reference to FIG.

FIG. 11 is a time chart of the throttle control during shifting. In particular, in the case of a stepped transmission, it is necessary to greatly change the gear ratio in a stepwise manner, and the auxiliary control by engine torque control is effective. That is, it is determined whether the current gear ratio Ir has reached the start timing k2 of the throttle control by applying the actual gear ratio Ir to determine whether the gear is currently being shifted. Then, when the time k2 comes, the engine speed predicted to be changed after the shift is predicted, and the throttle opening corresponding to the engine speed is calculated and output. At this time, the hydraulic pressure PL supplied to the clutch of the transmission is reduced in advance at the time when the shift start command signal is generated. Thereby, high-speed downshifting becomes possible. Then, at time k3, the throttle control for increasing the engine speed is ended, and the process proceeds to the target deceleration control described with reference to FIG. At the same time, the target engine torque Tet, that is, the target throttle opening θt
The hydraulic pressure PL is set in accordance with the above, and the hydraulic pressure PL is increased. As described above, in the target deceleration control, it is difficult to shift down with a decrease in the engine speed, and the coordinated control of the throttle and the oil pressure shown in FIG. 11 is indispensable.

FIG. 12 is a time chart showing the deceleration characteristics when the road gradient is changed, and FIG. 13 is a calculation block diagram of the target value corresponding to the running load.

In FIG. 12, the solid line shows the deceleration characteristics when the accelerator pedal depression amount α is zero on a flat ground, the dotted line shows the deceleration characteristics when the accelerator pedal depression amount α is zero on a downhill, and the wavy line shows the accelerator pedal on an uphill. This is a deceleration characteristic when the pedal depression amount α is set to zero. The deviation between the solid line, the dotted line, and the wavy line is the running load TL. As described above, the target deceleration requested by the driver is grasped at an arbitrary time after the accelerator pedal depression amount α becomes zero. For example, when the driver sets the accelerator pedal depression amount α to zero,
It is assumed that the power train is controlled so as to achieve the deceleration indicated by the solid line. This deceleration is the target value requested by the driver.

On the other hand, on a downhill, the traveling load is reduced, so that the deceleration is small, that is, the vehicle moves in the acceleration direction. Therefore, the driver has a feeling of strangeness and performs the braking operation because the deceleration is different from the deceleration requested by the driver. On an uphill, the traveling load increases, so that the deceleration is large, that is, the vehicle moves in the deceleration direction. Therefore, the driver feels uncomfortable and performs an accelerator operation because the deceleration is different from the deceleration requested by the driver.

Thus, by obtaining the travel load and determining and correcting the target deceleration in accordance with the travel load, acceleration control corresponding to a change in road gradient can be realized. Furthermore, the driving performance can be further improved by correcting the running load according to the driver's age and gender.

Next, the control logic shown in FIG. 12 will be described with reference to FIG. First, the vehicle speed No is input to the deceleration calculating means 45, and the actual deceleration Gd of the vehicle is calculated. The deceleration Gd, the accelerator pedal depression amount α and the brake depression force β are input to the target deceleration calculating means 46,
The target deceleration Gdt is calculated.

The calculation of the target deceleration Gdt is executed during the target deceleration grasp period in FIG. 12, when the accelerator pedal depression amount α is zero and the brake depression force β changes, as described above.

Next, the vehicle speed No, the turbine speed Nt, and the engine speed Ne are input to the drive shaft torque calculating means 47, and the actual drive shaft torque To is calculated. In the drive shaft torque calculating means 47, the drive shaft torque To is obtained from the torque converter characteristics and the speed ratio which changes abruptly at the start of the actual shift. For details of the calculation of the drive shaft torque, see
This is the same as the method described in detail in JP-A-207660.

Drive shaft torque To, deceleration Gd and vehicle speed N
o is input to the running load calculating means 48, and the running load TL is calculated. In FIG. 13, the running load TL is represented by a functional equation, but can be actually obtained by the following driving equation (1) of the vehicle.

TL = To−Iv · Gd (1) Iv: Vehicle inertia weight Finally, the traveling load TL and the target deceleration Gdt are input to the first target drive shaft torque calculating means 1, and A target value Ttar is calculated. This conversion formula is based on formula (1). Further, it may be obtained by experiments from actual vehicle characteristics. Subsequent calculations from the target engine torque calculation means 4 are the same as those in FIG.

The weight b of the function expression of the running load calculating means 48 in FIG. 13 will be described below.

Generally, different drivers have different preferences for deceleration when going up or down a hill, and the present invention allows this to be freely changed. A rewrite switch signal manually operated by the driver is input to the weight rewriting means 49,
It is possible to freely change the deceleration when going up or down a hill. That is, the weight b calculated by the weight rewriting means 49 is input to the running load calculating means 48, and the magnitude of the running load TL can be changed.

By applying the control logic as described above,
In addition to suppressing torque fluctuations from the power train when switching between the control amount for ensuring vehicle safety and the control amount for achieving the driver's intended state, acceleration and deceleration By preventing the occurrence, the deceleration required by the driver can be obtained in any traveling area from a flat ground to an uphill and downhill, and comfortable traveling can be achieved, and both safety and drivability can be achieved.

[0070]

According to the present invention, the switching between the control amount for ensuring the safety of the vehicle and the control amount for achieving the state intended by the driver is executed while reducing the shock from the power train. It is possible to achieve both safety and drivability.

[Brief description of the drawings]

FIG. 1 is a block diagram of control according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram of the present invention.

FIG. 3 is a time chart when a target value change from first to second is performed.

FIG. 4 is a time chart when the target value is changed from second to first.

FIG. 5 is a control block diagram of another embodiment.

FIG. 6 is a time chart of target deceleration control.

FIG. 7 is a time chart of deceleration-acceleration switching control.

FIG. 8 is a characteristic diagram schematically showing speed ratio control during deceleration.

FIG. 9 is a perspective view of a shift lever 40 for explaining an outline of a manual limit rotational speed setting method.

FIG. 10 is a time chart of the target deceleration control when the actual deceleration Gd is used.

FIG. 11 is a time chart of throttle control during shifting.

FIG. 12 is a time chart showing deceleration characteristics when a road gradient is changed.

FIG. 13 is a block diagram of calculation of a target value corresponding to a traveling load.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... First target drive shaft torque calculating means, 2 ... Target value changing means, 3 ... Target braking force calculating means, 4 ... Target engine torque calculating means, 5 ... Target gear ratio calculating means, 10 ... Second target drive Shaft torque calculating means, 11 ... limiter setting means.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 45/00 330 F02D 45/00 330 (72) Inventor Mitsuo Kayano 7-1-1, Omikacho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Tokuharu Yoshikawa 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory Hitachi, Ltd.

Claims (15)

[Claims] At least one of a drive shaft torque, a drive force, and an acceleration / deceleration of a transmission output shaft is set as a target value based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target value. In the control device of the vehicle, the predetermined target value between the first target value before the change and a second target value calculated according to the driving mode or the forward driving environment intended by the driver is determined in advance. A control device for a vehicle, wherein when a deviation exceeding a given value occurs, control is performed so as to suppress a fluctuation of at least one of the drive shaft torque, the driving force, and the acceleration / deceleration. 2. The method according to claim 1, wherein at least one of a drive shaft torque, a driving force, and an acceleration / deceleration of the transmission output shaft is set as a target value based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target value. A driving mode setting means for setting a driving mode intended by a driver, or an environment recognizing means for recognizing a forward driving environment, and a signal obtained by at least one of the two means. Target value changing means for changing the target value, when changing the target value, the deviation between the first target value before the change and the second target value calculated by the signal is a value equal to or more than a certain value And a torque fluctuation suppressing means for controlling the fluctuation of the drive shaft torque in a case where the fluctuation occurs. 3. The target value changing means according to claim 2, wherein, when the target value is changed by the target value changing means, a first target value before the change is set as an initial value for a predetermined period of time. And changing the first target value to a second target value when the deviation between the first target value and the second target value decreases to a predetermined value. Automotive control device. 4. The system according to claim 2, wherein the first target value is at least one of the drive shaft torque, the driving force, and the acceleration / deceleration calculated based on a driver's operation amount. The second target value is at least one of the drive shaft torque, the driving force, and the acceleration / deceleration calculated according to a signal obtained by the mode setting means or the environment recognition means, and at least an upper limiter is provided. A control device for an automobile. 5. The control apparatus according to claim 2, wherein the signals obtained by the driving mode setting means or the environment recognizing means are at least an inter-vehicle distance and a relative speed with respect to a preceding vehicle. 6. A control of an automobile for setting a target value of a drive shaft torque on a transmission output shaft side based on at least an accelerator pedal depression amount and an actual deceleration of the vehicle, and controlling a gear ratio in accordance with the target value. In the device, an engine brake control means for controlling an engine brake for transmitting a reverse driving force from the wheel to the engine; a brake force control means for controlling a brake force of the wheel according to the target value or to follow the target value; Controlling at least the engine torque and the gear ratio in accordance with the target value, and controlling the engine torque to a value close to a minimum value when the target value indicates a deceleration request, and controlling the engine while the braking force is being controlled. Speed ratio changing means for inhibiting engine brake control by brake control means and changing the speed ratio in accordance with the target value A vehicle control unit, characterized in that it consists of. 7. A target value of the drive shaft torque on the transmission output shaft side is set based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and at least the engine torque and the gear ratio are controlled in accordance with the target value. An acceleration / deceleration change determining unit that determines whether the target value has changed from a deceleration request to an acceleration request; and the acceleration / deceleration change determination unit determines that the request has changed from a deceleration request to an acceleration request. A control device for a motor vehicle, further comprising a speed ratio change width limiting means for limiting a width of change from a current speed ratio for a predetermined period when the speed ratio is changed. 8. A target value of the drive shaft torque on the transmission output shaft side is set based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and at least the engine torque and the gear ratio are controlled according to the target value. A target rotation speed calculating means for calculating a target value of the transmission input side rotation speed according to the target value; anda target rotation speed limit setting means for limiting the transmission input side rotation speed. A control device for an automobile, comprising: 9. A target value of a drive shaft torque on a transmission output shaft side is set based on at least an accelerator pedal depression amount and an actual deceleration of the vehicle, and at least engine torque and a gear ratio are controlled according to the target value. A target speed ratio calculating means for calculating a target value of the speed ratio in accordance with the target value; and a target speed ratio limit setting means for limiting the speed ratio. Car control device. 10. A drive shaft torque, a drive force, and an acceleration / deceleration at the transmission output shaft side are set as target values based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target values. In the method for controlling an automobile, a predetermined target value between the first target value before change as the target value and a second target value calculated according to a driving mode intended by the driver or a forward driving environment is set in advance. A method for controlling a vehicle to suppress at least one of the drive shaft torque, the driving force, and the acceleration / deceleration when a deviation exceeding a predetermined value occurs. 11. A method for setting at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on a transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controlling at least the engine torque according to the target value. In the method of controlling a vehicle, when the target value is changed in accordance with a signal obtained in at least one of a driving mode intended by a driver and a forward driving environment, the first target value before the change and the signal A control method for controlling the fluctuation of the drive shaft torque when the deviation from the second target value calculated by the above becomes a certain value or more. 12. A vehicle control system for setting a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controlling the speed ratio in accordance with the target value. Controlling an engine brake for transmitting reverse driving force from a wheel to an engine, controlling a wheel braking force according to the target value or following the target value, and controlling at least an engine torque and a speed change according to the target value. Controlling the engine torque to a value close to a minimum value when the target value indicates a deceleration request; prohibiting the engine brake control during a period in which the braking force is being controlled; A method for controlling an automobile, wherein the method is changed according to a target value. 13. At least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side is set as a target value based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target value. A drive shaft torque calculating means for calculating a drive shaft torque from a vehicle speed of the vehicle, an engine speed, and a turbine speed of the transmission; and a control unit for the vehicle based on a change in the vehicle speed of the vehicle. Deceleration calculating means for calculating an actual deceleration; calculating the running load of the vehicle from the vehicle speed, the deceleration calculated by the deceleration calculating means, and the drive shaft torque calculated by the drive shaft torque calculating means. Running load calculating means, and a target deceleration calculated at least by the deceleration calculating means and the accelerator pedal depression amount. Target deceleration calculating means for calculating deceleration, and a target value for calculating the target value according to the running load calculated by the running load calculating means and the target deceleration calculated by the target deceleration calculating means. A control device for an automobile, comprising a calculating means. 14. The control device for an automobile according to claim 13, wherein said running load calculating means includes a weight rewriting means capable of rewriting the magnitude of the calculated running load. 15. At least one of a drive shaft torque, a driving force, and an acceleration / deceleration on a transmission output shaft side is set as a target value based on at least an accelerator pedal depression amount, and at least engine torque is controlled in accordance with the target value. A drive shaft torque is calculated from a vehicle speed of the vehicle, an engine speed, and a turbine speed of the transmission, and an actual deceleration of the vehicle is calculated based on a change in the vehicle speed of the vehicle. Calculating a running load of the vehicle from the calculated deceleration, the vehicle speed, and the drive shaft torque; calculating a target deceleration based on at least the deceleration and the accelerator pedal depression amount; A control method for an automobile, wherein the target value is calculated according to the running load and the target deceleration.