JPH11210513A - Driving force control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the safe behavior of a vehicle without forcing a burden on a driver even in traveling environment where an obstruction such as another vehicle is in the point-blank range in front of or behind a vehicle at the time of starting the vehicle. SOLUTION: In a throttle opening target value computing part B102 of a driving control device, the target value TH0 of throttle opening can be obtained by processing up to mountainous bent road corresponding correction routine. In obstruction corresponding correction routine R403, the target value TH0 is multiplied by a correction factor KOBS to compute the final throttle opening target value TH. In obstruction corresponding correction factor computing routine R310, the correction factor KOBS is set to the value very close to zero in the case of a state of emergency being recognized, so as to forcibly reduce the final throttle opening target value TH.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force control device for a vehicle suitable for use in a vehicle equipped with an engine having an electronically controlled throttle.

[0002]

2. Description of the Related Art How to ensure safety and operability of vehicle behavior. This has been a central issue in vehicle development and design. In order to solve this problem, there has been a demand for a function of controlling a vehicle so as to exhibit a behavior that is safe and faithful to the driver's will in various driving environments.

[0003] However, the content of the driving environment is quite diverse. First, the types, widths, shapes, and the like of roads on which vehicles travel, such as general roads, highways, city streets, mountain roads, and curved roads, can be said to be important components of the driving environment. Further, the driver who drives the vehicle may try to accelerate, or conversely, try to decelerate, or even try to drive at a constant speed, and such a driver's will also constitutes a driving environment. . In addition, even if the road is the same, the traveling environment changes drastically between when the road is vacant and when there is traffic, and in this sense, the presence of other vehicles on the road also constitutes the traveling environment.

[0004] In order to realize a vehicle excellent in safety and operability, various driving environments constituted by such various elements are assumed, and in any driving environment, the vehicle can be safely and faithfully adhered to the driver's will. It is necessary to design control means that can drive the vehicle.

In such a background, the driving environment in which the vehicle is placed is detected through some kind of sensor, and the driving force of the engine mounted on the vehicle is controlled in a manner suitable for the driving environment. Various technologies have been proposed. For example, a driving parameter (for example, a vehicle speed) of a vehicle is detected by a sensor, a driving environment is estimated from the driving parameter by fuzzy inference, and a throttle opening of an electronic control throttle corresponding to an accelerator pedal opening is determined based on the estimation result. A device for optimizing the gain of the above has been proposed (JP-A-63-268943). Further, there has been proposed a technique of estimating a degree of traffic congestion on a road from an average vehicle speed and a frequency of starting and stopping per unit time in a vehicle equipped with an electronic control throttle, and controlling a driving force based on the estimation result. Further, in addition to this, a technology has been proposed in which a distance between vehicles is detected by a sensor, the accuracy of estimating the degree of congestion is improved based on the result of the detection, and the operation of stepping on a brake and an accelerator at the time of starting or the like is reduced. Kaiping 4
-365935).

[0006]

In the above-mentioned prior art, the running environment is estimated from the average vehicle speed, the start / stop frequency, the inter-vehicle distance, and the like, and the target throttle opening of the engine is set based on the estimation result. However, the calculation process up to obtaining the estimation of the traveling environment includes time-consuming processes such as average value calculation and frequency calculation. For this reason, it takes some time until the estimation result is obtained. Therefore, although the time is relatively short, there is a possibility that the currently obtained estimation result does not match the current traveling environment, and a suitable throttle opening control corresponding to the traveling environment is not performed.

One of the disadvantages is particularly problematic, for example, when a vehicle starts or re-accelerates from extremely low speed running, etc., within a short distance in front of or behind the vehicle. This is a problem that occurs in a driving environment where there is an obstacle. That is, in such a case, even if there is an accelerator operation of the driver requesting acceleration, the throttle opening degree control is not performed in accordance with the accelerator operation, and the throttle opening degree is particularly considered in consideration of the presence of an obstacle ahead or behind. It is desired to control to a small value. However, in the related art, the control of the throttle opening corresponding to the obstacle in front or behind is not immediately performed when the vehicle starts, due to the delay in the estimation of the traveling environment. For this reason, the behavior of the vehicle suitable for the traveling environment cannot be obtained, and the driver is forced to perform an operation of correcting the behavior by alternately depressing the accelerator pedal and the brake pedal.

[0008] The present invention has been made in view of the above circumstances, and when a vehicle starts or re-accelerates from extremely low speed traveling, etc., obstacles of other vehicles or the like within a short distance in front of or behind the vehicle. It is an object of the present invention to provide a vehicle driving force control device capable of obtaining safe vehicle behavior without imposing a burden on a driver when there is an object.

[0009]

SUMMARY OF THE INVENTION The present invention has a driving means for calculating a target throttle opening corresponding to an accelerator operation, and for controlling a throttle opening of an engine of a vehicle in accordance with the target throttle opening. In the device, a stop state detecting means for detecting that the vehicle is in a stopped state or an extremely low speed running state, a distance detecting means for detecting a distance to an obstacle in front of or behind the vehicle, and a shift position Shift position detecting means, when the stop state detecting means detects that the vehicle is in a stopped state or an extremely low speed running state, and when the shift position detected by the shift position detecting means belongs to a traveling range, The target throttle opening set in the control of the throttle opening of the engine is detected by the distance detecting means. The driving force control apparatus for a vehicle characterized by comprising the obstacle corresponding correction means decreases the correction in accordance with the release and gist.

According to this invention, in a traveling environment where there is an obstacle such as another vehicle within a short distance in front of or behind the vehicle when the vehicle starts or re-accelerates from extremely low speed traveling, etc. Even if there is an accelerator operation of the driver requesting acceleration, throttle opening control is not performed in accordance with the accelerator operation, and the target throttle opening is corrected to a smaller value in response to the presence of an obstacle ahead or behind. Therefore,
Even in such a running environment, safe vehicle behavior can be obtained without imposing a burden on the driver.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an entire configuration of a driving force control device B100 according to an embodiment of the present invention and peripheral devices thereof. The driving force control device B100 according to the present embodiment is a device that controls the driving force of the vehicle by controlling the throttle opening of an electronically controlled throttle (not shown) mounted on the vehicle. Focusing on the hardware of the driving force control device B100, the device B1
Reference numeral 00 denotes a central processing unit (CPU), a RAM (random access memory) for temporarily storing control information and calculation information, a ROM (read only memory) storing various control information and control programs, and a battery backup. It can be said that it is constituted by a nonvolatile memory such as a RAM, a power supply circuit, and other circuits (all not shown). However, in order to grasp the contents of the present invention, rather than providing an explanation corresponding to such hardware components, the driving force control device B1
It seems that it is more effective to block the functions performed by 00 and provide an explanation based on this. FIG. 1 is a hardware representation of the functions performed by the driving force control device B100 in accordance with such an intention.

The driving force control device B100 according to the present embodiment.
As shown in FIG. 1, an input unit B101, a throttle opening target value calculation unit B102, and a throttle opening control unit B103 are main functional components. Here, the input unit B101 is a unit serving as an interface with the sensor group SEn attached to each unit of the vehicle. The details of the sensor group SEn will be described later. Next, a throttle opening target value calculation unit B10
2 is a sensor group SE supplied via the input unit B101.
This is means for calculating the target value TH of the throttle opening in the throttle control based on each output signal of n, and corresponds to the "calculating means" described in the claims of the present application. This throttle opening target value calculation unit B102
Are means provided by the CPU executing the various control programs stored in the ROM.
The details of these control programs will be described later. The throttle opening control unit B103 is means for driving the electronic control throttle via the throttle drive actuator B200 to control the throttle opening of the electronic control throttle to reach the target value TH.

[0013] The driving force control device B100 according to the present embodiment.
Plays a central role in the throttle opening target value calculation unit B102. FIG. 2 is a block diagram showing the function of the throttle opening target value calculation unit B102 in terms of hardware.

FIG. 2 shows a large number of rectangular blocks, which represent the control routines in the ROM executed by the CPU.

Further, SE1 to SE9 represent each sensor or switch constituting the above-mentioned sensor group SEn. The following briefly describes these sensors or switches.

First, the vehicle speed sensor SE1 is a sensor that outputs a pulse signal every time a tire of a vehicle rotates a predetermined angle. The input unit B101 counts this pulse signal, generates vehicle speed data V based on the number of pulses counted per unit time, and provides it to the throttle opening target value calculation unit B102.

Next, the inter-vehicle distance sensor SE2 is a sensor that measures the inter-vehicle distance to the vehicle in front or behind using a laser or the like and outputs inter-vehicle distance data D representing the measured inter-vehicle distance. This inter-vehicle distance sensor SE2 corresponds to "distance detecting means" described in the claims of the present application. The accelerator opening sensor SE3 is a sensor that outputs accelerator opening data AP corresponding to the accelerator opening, that is, the depression angle of the accelerator pedal. The brake switch SE4 is a switch that is turned on when a brake pedal is depressed. The yaw rate sensor SE5 is a sensor that outputs yaw rate data YR according to the steering direction and the steering angle when the vehicle is steered left and right.

The engine speed sensor SE6 outputs a pulse signal every time the engine rotates a predetermined angle. This pulse signal is also counted by the above-described input unit B101, engine speed data NE is generated from the pulse count number per unit time, and given to the throttle opening target value calculation unit B102.

The intake pipe negative pressure sensor SE7 is a sensor that outputs negative pressure data PB representing negative pressure generated in the intake pipe of the engine. The gear ratio sensor SE8 is a sensor that detects a gear ratio of a transmission gear of the automatic transmission and outputs gear ratio data GR. The shift position sensor SE9 is a sensor that detects a shift position of the automatic transmission and outputs shift position data ATPOSI representing a detection result. The shift position sensor SE9 corresponds to "shift position detecting means" described in the claims of the present application. The above is the outline of the sensor group SEn.

In FIG. 2, these sensors and some routines are connected by arrows. These arrows show how the output data of each sensor is delivered to each routine. Also, in FIG. 2, many routines are connected by arrows, and these show how the calculation results are passed between the routines.

The outline of the role of each routine shown in FIG. 2 will be described as follows. First, the routines R101 to R1
08 constitutes means for acquiring various operation parameters via a sensor group. Next, the routine R201
R208 constitute a means for estimating the traveling environment from the driving parameters and calculating the target vehicle speed and the target inter-vehicle distance. Next, the routines R301 to R310
A means for calculating each correction coefficient required for calculating the target throttle opening TH based on the operating parameters, the traveling environment, and the like is configured. Then, the routines R401 to R403
Constitutes means for calculating the target throttle opening TH using each correction coefficient.

Among the routines described above, the most significant feature of the present embodiment is that an obstacle correspondence correction coefficient calculation routine R310 is used.
And a final stage obstacle handling correction routine R403 of the three routines for calculating the target throttle opening TH. Here, the role of these routines will be described.

First, in the present embodiment, by executing the above-described routines, operating parameters such as an average vehicle speed, a start / stop frequency, an inter-vehicle distance, and the like are calculated, and a traveling environment is estimated from these operating parameters. By executing the processing up to the mountain curved road correction routine R402 preceding the obstacle correction routine R403, the target value TH0 of the throttle opening of the engine suitable for each operating parameter and the driving environment is calculated. .

However, the average vehicle speed, the start / stop frequency, the inter-vehicle distance, etc., necessary for estimating the driving environment are calculated as an average value.
Since it is obtained through a time-consuming process such as frequency calculation, it takes a certain amount of time until the estimation of the traveling environment is completed and the target value TH0 of the throttle opening reflecting this estimation result is obtained. Therefore, although it is a relatively short time, it may temporarily occur that the currently obtained estimation result does not match the current driving environment.

However, when the vehicle is in a running environment in which there is an obstacle such as another vehicle within a short distance in front of or behind the vehicle when the vehicle starts or when the vehicle is re-accelerated from extremely low speed, for example, Alternatively, it is necessary to promptly make a correction to reduce the throttle opening to a small value in consideration of the existence of an obstacle behind. However, if the above-mentioned delay in the estimation of the traveling environment occurs, this quick throttle opening correction is not performed, and a burden is imposed on the driver.

Obstacle Correspondence Correction Coefficient Calculation Routine R310
The obstacle handling correction routine R403 is provided to deal with such a problem, and corresponds to the "obstacle handling correcting means" described in the claims of the present application.

That is, an obstacle handling correction routine R40
In step 3, the correction coefficient KOBS supplied from the obstacle correction coefficient calculation routine R310 is multiplied by the throttle opening target value TH0 to calculate the final throttle opening target value TH. Routine R310
Then, when it is recognized that the vehicle is in the running environment as described above, the correction coefficient KOBS is set to a value very close to 0, and the final throttle opening target value TH is forcibly reduced. . This is the role of the obstacle correspondence correction coefficient calculation routine R310 and the obstacle correspondence correction routine R403, which are the greatest features of the present embodiment. Here, the correction coefficient KOBS is calculated from only the vehicle speed data V, the following distance data D, and the shift position data ATPOSI.
This calculation process does not include a calculation process that requires a long time such as a statistical process. Therefore, when the vehicle is in the above-mentioned traveling environment, the operation of forcibly reducing the target value TH of the throttle opening is immediately performed.

FIGS. 3 to 5 are flowcharts illustrating the procedure when the CPU executes each routine shown in FIG. In addition, in order to clarify the correspondence between each routine in the block diagram of FIG. 2 and each routine in each of the flowcharts of FIGS. 3 to 5, the same reference numeral is used for each routine. . Hereinafter, the throttle opening target value calculation unit B10 will be described in accordance with these flowcharts.
Operation 2 will be described.

In this embodiment, a fixed time interval (for example, 1
00 ms), a timer interrupt signal is given to the CPU.
Then, the CPU executes a timer interrupt routine shown in FIG. 3 every time the timer interrupt signal is given. In this timer interrupt routine, first, an operation parameter calculation routine R100 is executed. FIG. 4 is a flowchart showing the processing content of the operation parameter calculation routine R100.

First, in the average vehicle speed calculation routine R101, based on the vehicle speed data V, the average vehicle speed data VAVE is calculated according to the following equation (1). VAVE (n) = {CVAVE.V + (256-CVAVE) .VAVE (n-1)} / 256 (1)

In the above equation (1), VAVE (n
-1) is the average vehicle speed data obtained during the previous execution of the average vehicle speed calculation routine R101, and VAVE (n) is the average vehicle speed data obtained this time. CVAVE is an average vehicle speed calculation smoothing coefficient.

FIG. 6 is a block diagram showing the arithmetic expression (1) in terms of hardware. In the figure, reference numerals 11 and 12 denote multipliers, reference numeral 13 denotes an adder, and reference numeral 14 denotes a delay unit having a delay time corresponding to a timer interrupt signal generation cycle. As is clear from FIG. 5, the arithmetic processing by the arithmetic expression (1) is for performing a low-pass filter processing on the vehicle speed data V. Then, the average vehicle speed calculation smoothing coefficient CV
AVE acts as a time constant and determines the frequency characteristics of the low-pass filter processing. When the temporal change of the vehicle speed data V is relatively moderate, the average vehicle speed data VAVE corresponding to the moving average of the vehicle speed data V is obtained by the low-pass filter processing.

Since the average vehicle speed data VAVE is calculated by processing including such a time constant, the average vehicle speed data VAVE does not immediately follow a change in the vehicle speed data V, but changes slightly with respect to the vehicle speed data V. .

Next, in the average inter-vehicle distance calculation routine R102, the average inter-vehicle distance data VAVE is calculated from the inter-vehicle distance data D by an arithmetic expression having a smoothing coefficient similar to that of the average vehicle speed calculation routine R101. Since the average inter-vehicle distance data DAVE is also calculated by a process including a time constant, the average inter-vehicle distance data DAVE changes slightly with respect to the change in the inter-vehicle distance data D.

Next, in a start / stop frequency calculation routine R103, start / stop frequency data SGR representing the frequency of start / stop of the vehicle per unit time is calculated based on the vehicle speed data V. The start stop frequency data SGR is obtained by monitoring the behavior of the vehicle speed data V within a certain period in the past. Here, in order to obtain an accurate start / stop frequency, it is necessary to set the period for monitoring the vehicle speed data V to an appropriate length. For this reason, when the frequency of the actual start and stop of the vehicle changes with time, the temporal change of the start and stop frequency data SGR occurs with a slight delay.

Next, in the accelerator pedal operation speed calculation routine R104, the accelerator opening data AP (n-1) at the timing one timer interrupt cycle earlier is subtracted from the current accelerator opening data AP (n), whereby ,
The accelerator operation speed data DAP is obtained.

Next, in the acceleration calculation routine R105, the vehicle speed data V (n-1) at the timing one timer interrupt cycle earlier is subtracted from the current vehicle speed data V (n), whereby the acceleration representing the vehicle acceleration is obtained. Data DV
Ask for.

Next, in the relative speed calculation routine R106,
The inter-vehicle distance data D (n−n) at the timing one timer interrupt cycle before the current inter-vehicle distance data D (n)
By subtracting 1), relative speed data DD representing the relative speed of the preceding vehicle as viewed from the own vehicle is obtained.

Next, an inter-vehicle distance movement standard deviation calculation routine R
In 107, the inter-vehicle distance data D in the past fixed period
(K) An average value of (k = n-N + 1 to n), that is, a moving average value of the inter-vehicle distance data D is obtained, and further, each inter-vehicle distance data D (k) (k = n-N + 1 to n) and this movement are calculated. The sum of the squares of each difference from the average value is calculated, and the moving standard deviation DSIG of the inter-vehicle distance data D is calculated from the total value.

In the relative speed movement standard deviation calculation routine R108, a moving average value of the relative speed data DD is obtained from the relative speed data DD (k) (k = n-N + 1 to n) calculated in the past fixed period. Further, the sum of the square of each difference between each relative speed data DD (k) (k = n−N + 1 to n) and this moving average value is calculated, and the moving standard deviation DDSIG of the relative speed data DD is calculated from the total value. calculate. The above is the processing content of the operation parameter calculation routine R100.

In the timer processing routine R1 (FIG. 3), when the operation parameter calculation routine R100 ends, the process proceeds to an intention determination threshold value calculation routine R201. In the intention determination threshold value calculation routine R201, the threshold values used in the following intention determination routine R204, which will be described later, are set to the average vehicle speed data VAVE and the start stop frequency data S.
It is calculated from the GR and the average inter-vehicle distance data DAVE.
This threshold value will be described later.

Next, in an acceleration intention estimation routine R202,
Acceleration will accumulated data ACCSUM representing the driver's acceleration intention is calculated by fuzzy inference using the accelerator opening data AP and the accelerator pedal operation speed data DAP. Here, with reference to FIG. 7, a description will be given of a calculation procedure of the acceleration intention integrated data ACCSUM in the acceleration intention estimation routine R202.

In this embodiment, the membership functions shown in FIGS. 7A to 7D are prepared. First, FIG.
Membership function MEM1 shown in (a) and (b)
1 and MEM12 are both accelerator opening data A
A function in which P is an independent variable. Here, the function value MEM11 (AP) of the membership function MEM11 indicates how valid the proposition "accelerator opening is small" when the accelerator opening data is AP. On the other hand, the function value MEM12 (AP) of the membership function MEM12 indicates how valid the proposition "accelerator opening is large" when the accelerator opening data is AP. In the acceleration intention estimation routine R202, first, the function value uACC1 = MEM corresponding to the accelerator opening data AP at the present time is obtained from these membership functions MEM11 and MEM12.
11 (AP) and uACC2 = MEM12 (AP).

Next, the membership functions MEM21 and MEM22 shown in FIGS. 7C and 7D are functions using the accelerator pedal operation speed data DAP as an independent variable. Here, the membership function MEM21
The function value MEM21 (DAP) of the expression represents how valid the proposition "accelerator pedal operation speed is low" when the accelerator pedal operation speed data is DAP. On the other hand, the membership function MEM22
The function value MEM22 (DAP) of the expression represents how valid the proposition "accelerator pedal operation speed is high" when the accelerator pedal operation speed data is DAP. In the acceleration intention estimation routine R202,
These membership functions MEM21 and MEM2
2 to the current accelerator pedal operation speed data D
Function value vACC1 corresponding to AP = MEM21 (DA
P) and vACC2 = MEM22 (DAP).

Next, in an acceleration intention estimation routine R202,
Accelerated will data ACCM is calculated by fuzzy synthesis using a predetermined production rule. This fuzzy synthesis is performed as follows. First, in FIG. 7E, wACC11 is “accelerator opening is small”,
In addition, it is acceleration will data when the "accelerator pedal operation speed is low". The wACC 12 is acceleration intention data when the “accelerator opening is small” and the “accelerator pedal operation speed is high”. Also, wA
CC21 is acceleration intention data when “accelerator opening is large” and “accelerator pedal operation speed is small”. The wACC 22 is acceleration intention data when “accelerator opening is small” and “accelerator pedal operation speed is large”.

In the acceleration intention estimation routine R202, these acceleration intention data wACC11, wACC12, wA
Using CC21 and wACC22 and already obtained membership function values uACC1, uACC2, vACC1 and vACC2, acceleration intention data A is calculated by the following equation.
Calculate CCM. ACCM = {uACC1.vACC1.wACC11 + uACC1.vACC2.wACC12 + uACC2.vACC1.wACC21 + uACC2.vACC2.wACC22} / {uACC1.vACC1 + uACC1.vACC2.multidot ..

Next, in the acceleration intention estimating routine R202, acceleration intention integrated data ACCSUM is calculated according to the following equation. ACCSUM (n) = ACCSUM (n-1) + ACCM (3) The above is the processing contents of the acceleration intention estimation routine R202.

Next, in the deceleration intention estimation routine R203,
Acceleration will accumulated data DECS indicating driver's intention to decelerate
UM is calculated. Here, the deceleration intention estimation routine R20
When the brake switch SE4 is in the ON state at the time of the execution of 3, the deceleration intention integrated data DECSUM is set to a predetermined upper limit value DECSUMH. If the acceleration intention data ACCM is 0 or more at the time of execution,
The deceleration intention integrated data DECSUM is a predetermined lower limit value DEC
Set to SUML. In cases other than the above, deceleration will data D is obtained from the accelerator opening data AP and the accelerator pedal operation speed data DAP by the same fuzzy inference as in the acceleration intention estimation routine R202 described above.
The EC is calculated, and the intention to accelerate data DECSUM is calculated by integrating the intention to decelerate data DEC.

Next, in the tracking intention estimating routine R204,
Based on the same fuzzy inference as the acceleration intention estimation routine R202 and the like, the following intention integrated data ADPT indicating the degree of the driver's following intention is calculated, and the following intention integrated data ADPT is calculated by integrating the following intention integrating data ADPT.
Calculate SUM.

Here, the follow-up intention data ADPT is calculated by executing fuzzy inference from the inter-vehicle distance movement standard deviation DSIG or fuzzy inference from the relative movement speed standard deviation DDSIG depending on the situation. Further, when calculating the following intention data ADPT by fuzzy inference from the inter-vehicle distance movement standard deviation DSIG, a membership function value corresponding to the inter-vehicle distance movement standard deviation DSIG is obtained. Is also used depending on the magnitude of the inter-vehicle distance movement standard deviation DSIG. The same applies to the case where the following intention data ADPT is calculated by fuzzy inference from the relative movement speed standard deviation DDSIG.

Such “selection” is performed accurately by selecting a fuzzy inference method and a membership function suitable for the driving environment in view of the large range of changes in the driving environment in which the vehicle is placed. This is to estimate the will to follow. The threshold value calculated by the intention determination threshold value calculation routine R201 described above is control information used for the switching control of the “selection”.

Next, in a stability estimation routine R205, a stability STBM of the behavior of the vehicle within a unit time is calculated from the acceleration intention accumulated data ACCSUM and the deceleration intention accumulated data DECSUM by fuzzy inference.
The stability α is estimated by integrating the BM. Note that the stability α
, An upper limit value and a lower limit value are set according to the vehicle speed data V.

Next, in the target vehicle speed calculation routine R206,
The target vehicle speed VCMD, which is considered to be appropriate in the case where the vehicle is driven at a constant speed, is calculated. That is, when the stability α is larger than the predetermined value, the target vehicle speed calculation smoothing coefficient is determined according to the stability α, and the low-pass filter processing using the target vehicle speed calculation smoothing coefficient (the average vehicle speed calculation routine R101 is already performed). Is applied to the vehicle speed data V to thereby obtain the target vehicle speed V.
Find CMD. If the stability α is less than the predetermined value, the current vehicle speed data V is directly used as the target vehicle speed VCM.
Set as D.

Next, in a target inter-vehicle distance calculation routine R207, a target inter-vehicle distance DCMD that is considered to be appropriate if the vehicle is to follow up is calculated. That is, when the stability α is larger than the predetermined value, the target inter-vehicle distance calculation smoothing coefficient is determined according to the stability α, and the low-pass filter processing using the target inter-vehicle distance calculation smoothing coefficient is performed on the inter-vehicle distance data D. To obtain the target inter-vehicle distance DCMD. If the stability α is less than the predetermined value, the current inter-vehicle distance data D is set as the target vehicle speed DCMD as it is.

Next, in the macro environment estimation routine R208, the average vehicle speed data VAVE, the start stop frequency data SGR, and the average inter-vehicle distance data DA are obtained by fuzzy inference.
A macro environment estimated value KAPBASE is calculated from VE.
The macro environment estimated value KAPBASE is an estimated value indicating the state of the flow of the vehicle, such as whether the road is empty and the vehicle is flowing smoothly, or conversely, the road is crowded and the vehicle is traveling slowly. .

Next, when the macro environment estimation routine R208 is completed, the routine proceeds to a correction coefficient calculation routine R300. FIG. 5 shows a flow of the correction coefficient calculation routine R300.

First, in the constant speed traveling correction coefficient calculation routine R301, the vehicle speed data V and the target vehicle speed data VCMD are calculated.
From this, a constant speed traveling correction coefficient KCRS is calculated. Here, the constant-speed running correction coefficient KCRS is a throttle opening calculation correction coefficient for correcting the throttle opening so as to maintain the vehicle speed at the target vehicle speed when running at a constant speed. This routine for calculating the correction coefficient for constant speed traveling R301
Then, a PI calculation including a predetermined P element (proportional element) and I (integral element) is performed on the difference between the target vehicle speed data VCMD and the vehicle speed data V to calculate a constant speed traveling correction coefficient KCRS. I do.

Next, a correction coefficient calculation routine R for following running is performed.
At 302, the following distance data D and the target following distance data D
A follow-up running correction coefficient KADPT is calculated from the CMD. Here, the correction coefficient for follow-up running KADPT is a throttle-opening calculation correction coefficient for correcting the throttle opening to keep the inter-vehicle distance to the preceding vehicle at the target inter-vehicle distance when performing the follow-up running. In the follow-up traveling correction coefficient calculation routine R302, the difference between the target inter-vehicle distance data DCMD and the inter-vehicle distance data D is calculated based on P including a predetermined P element (proportional element) and I (integral element).
By performing the I operation, the correction coefficient KAD for following running is calculated.
Calculate PT.

Next, a routine R30 for calculating a correction coefficient for acceleration.
3, the acceleration correction coefficient KA is calculated according to the procedure described below.
Calculate CC.

First, the tracking intention integrated data ADPTSUM
Is less than or equal to the predetermined value, it is considered that the driver does not intend to follow the vehicle. Therefore, a correction coefficient calculation table for acceleration prepared in advance assuming free driving is searched to obtain a correction coefficient for acceleration KACC corresponding to the acceleration intention integrated data ACCSUM. In this case, the acceleration correction coefficient KAC proportional to the acceleration intention integrated data ACCSUM
C will be obtained. However, the acceleration correction coefficient KACC is limited within a range from a certain upper limit to a lower limit so that excessive acceleration or insufficient acceleration does not occur.

On the other hand, the tracking intention integrated data ADPTSUM
Is larger than the predetermined value, it is considered that the driver intends to follow the vehicle. Therefore, the acceleration correction coefficient calculation table prepared in advance for the following running is searched to find the acceleration correction coefficient KACC corresponding to the acceleration intention integrated data ACCSUM. Next, a table search for correcting the acceleration correction coefficient KACC itself is performed.
More specifically, in the following traveling, it is necessary to perform an operation of correcting the acceleration of the own vehicle in accordance with the relative speed with respect to the preceding vehicle so as to maintain a constant inter-vehicle distance with the preceding vehicle. A table of the target throttle opening calculation correction coefficient for performing the correction operation is prepared in advance. Therefore, this table is searched and the relative speed data D
The correction coefficient corresponding to D is obtained. The acceleration correction coefficient KACC corresponding to the acceleration intention integrated data ACCSUM is multiplied by the obtained correction coefficient.
Is corrected. Through the above processing, the acceleration correction coefficient KACC reflecting the driver's intention to accelerate and taking into account the correction necessary for following the vehicle is obtained.

Next, a deceleration correction coefficient calculation routine R30
In step 4, a deceleration correction coefficient KDEC is calculated from the deceleration intention integrated data DECSUM, the relative speed data DD, the following intention integrated data ADPSUM, and the acceleration data DV. The procedure for calculating the deceleration correction coefficient KDEC in this routine is almost the same as the procedure for calculating the acceleration correction coefficient KACC. By executing this routine, a deceleration correction coefficient KDEC that reflects the driver's intention to decelerate and that takes into account the correction necessary for following the vehicle is obtained.

Next, a deceleration correction coefficient calculation routine R3
Upon completion of 04, the process proceeds to a routine R305 for calculating a correction coefficient according to the vehicle speed or the following distance. This routine R
At 305, when the following intention integration data ADPTSUM is small and the following intention of the driver is not estimated,
Select the correction coefficient KCRS for constant speed traveling and select the correction coefficient KF
B. On the other hand, when the following intention integration data ADPTSUM is large and the following intention of the driver is estimated, the correction coefficient KADPT for following driving is selected and the correction coefficient KF
B.

Next, when the routine R305 ends, a routine R30 for calculating a correction coefficient corresponding to the accelerator opening degree.
Proceed to 6. In this routine R306, a macro environment estimated value KAPBASE, a correction coefficient KACC for acceleration, and a correction coefficient KDEC for deceleration are multiplied to obtain a correction coefficient KFF corresponding to the accelerator opening.

Next, a running resistance table search routine R30
At 7, a search of the running resistance table is performed. That is, in the present embodiment, the running resistance table showing the relationship between the vehicle speed and the running resistance acting on the vehicle at the vehicle speed is RO.
M (not shown) is stored in advance, and the running resistance table search routine R307 searches the running resistance table for the running resistance TRL corresponding to the current vehicle speed data V.

Next, in a gradient estimation routine R308, the gradient SLP of the road on which the vehicle is traveling is estimated from the engine speed data NE, the intake pipe negative pressure data PB, the gear ratio data GR, and the traveling resistance TRL. Is calculated. The slope-dependent correction coefficient KD is a correction coefficient for adding a correction corresponding to the road gradient to the target value of the throttle opening.

Next, in a corner radius estimation routine R309, a corner radius (curvature radius) R of the road on which the vehicle is traveling is estimated from the vehicle speed data V and the yaw rate data YR, and a corner correction coefficient KR corresponding to the corner radius R is estimated. Is calculated. The corner correction coefficient KR is a correction coefficient for adding a correction corresponding to the progress of the vehicle while turning right or left, to the target value of the throttle opening.

Next, upon completion of the routine R309, the flow proceeds to an obstacle-corresponding correction coefficient calculation routine R310. The role of the obstacle-corresponding correction coefficient calculation routine R310 has already been described. Here, the specific processing will be described with reference to the flowchart shown in FIG.

First, in step S701, it is determined whether the vehicle speed data V is smaller than a predetermined lower limit value VLOWWLMT. If the result of this determination is "YES", the flow proceeds to step S702, and "NO". In this case, the process proceeds to step S707. The determination processing in step S701 corresponds to "stop state detecting means for detecting that the vehicle is in the stop state or the extremely low-speed running state" described in the claims of the present application. And the lower limit value VLO
WLMT is equivalent to a reference value for determining “stop state or extremely low speed state”, for example, 2 km / h.
A degree value is used.

Next, in step S702, it is determined whether or not the inter-vehicle distance data D is smaller than a predetermined lower limit value DLOWWLMT. If the result of this determination is “YES”, the flow proceeds to step S703, and if “NO”, the flow proceeds to step S707. Here, the lower limit value DLOWWLMT in step S702 has a significance as a reference value when determining whether or not there is an obstacle within a short distance in front of or behind the vehicle based on the inter-vehicle distance data D. is there. As the lower limit value DLOWLMT, a distance that the vehicle can travel reliably, for example, a value of about 3 m is used. In the claims of the present application, the invention specifying matter of "obstacle correspondence correction means" is described, but the lower limit DL
The OWLMT is a “predetermined value” in “when the distance detected by the distance detecting means is smaller than a predetermined value” which is one of the requirements for the “obstacle corresponding correcting means” to correct the target throttle opening. Value ".

At step S703, it is determined whether the shift position is N (neutral) or P (parking) based on the shift position data ATPOSI. If the result of this determination is "YES", the flow proceeds to step S707, and if it is "NO", the flow proceeds to step S704.

Next, in step S704, it is determined whether or not the shift position is R (rear) based on the shift position data ATPOSI. If the result of this determination is "YES", the flow proceeds to step S705, and if it is "NO", the flow proceeds to step S706.

According to the above-described determination of each step, when the vehicle speed data V is equal to or more than the predetermined lower limit value VLOWWLMT, when the inter-vehicle distance data D is equal to or more than the predetermined lower limit value DLOWWLMT, or when the shift position is N (neutral) or P (Parking), step S7
07, and “1.0” is set as the obstacle correspondence correction coefficient KOBS. That is, in this case, the target throttle opening corresponding to the obstacle is not corrected because there is no obstacle such as the vehicle within the close distance ahead or in the shift position where the driving force of the engine is not transmitted to the wheels. .

Then, the vehicle speed data V is set to a predetermined lower limit value VL.
If it is smaller than OWLMT and the inter-vehicle distance data D is smaller than a predetermined lower limit value DLOWLMT, and if the shift position is R (reverse), step S7.
The process proceeds to 05, and the correction coefficient value KOBSR for reverse is set as the obstacle correspondence correction coefficient KOBS. This correction coefficient value KOBSR is a value extremely close to 0 or 0.
It is.

The vehicle speed data V is set to a predetermined lower limit value VLO.
When the shift position is not N (neutral), P (parking), or R (reverse), that is, when the vehicle-to-vehicle distance data D is smaller than a predetermined lower limit value DLOWLMT. If it is in the shift position for performing the forward drive of step S
706, the obstacle correspondence correction coefficient KOBS
Is set as the forward correction coefficient value KOBSD. This correction coefficient value KOBSD is a value extremely close to 0 or 0.

As described above, in the obstacle-corresponding correction coefficient calculation routine R310, there is an obstacle such as another vehicle within a short distance in front of or behind the vehicle, and the shift position is in the travel range (including both forward drive and reverse drive). ), The obstacle-corresponding correction coefficient KOBS is a value very close to 0 or a correction coefficient value KOBSD that is 0 (when moving forward).
Alternatively, the correction coefficient value KOBSR (at the time of reverse travel) is set. The above is the obstacle correction coefficient calculation routine R31.
0 is the processing content.

Obstacle Corresponding Correction Coefficient Calculation Routine R310
Is completed, the entire processing of the correction coefficient calculation routine R300 ends. Then, the target throttle opening calculation routine R40 in the timer interrupt routine
It will advance to 1.

This target throttle opening calculation routine R4
01, using the correction coefficient KFF corresponding to the accelerator opening obtained at that time, the correction coefficient KFB corresponding to the vehicle speed or the inter-vehicle distance, and the stability α, according to the following equation:
The target throttle opening THFF is calculated. THFF = KFF · KFB · α (4)

Next, a correction routine R402 for a mountainous curved road
Then, as shown in the following equation, the target throttle opening degree THF is determined by the corner correction coefficient KR and the gradient correction coefficient KD.
F is corrected, and the corrected target throttle opening TH0 is corrected.
Is required. TH0 = KR / KD / THFF (5)

Next, in the obstacle correspondence correction routine R403, the target throttle opening TH0 is corrected by the obstacle correspondence correction coefficient KOBS as shown in the following equation, and the final target throttle opening TH is obtained. . TH = KOBS.TH0 (6)

Here, the correction coefficient KOBS is calculated only from the vehicle speed data V, the following distance data D and the shift position data ATPOSI, as already described with reference to FIG. Does not include arithmetic processing that takes a long time. Therefore, when the vehicle is started or when the vehicle is re-accelerated from extremely low speed, the traveling environment is such that there is an obstacle such as another vehicle within a short distance in front of or behind the vehicle. By the correction coefficient calculation routine R310, the correction coefficient KOBS is immediately reduced to an extremely small value, and an operation for forcibly reducing the target throttle opening TH is performed.

Thus, the final target throttle opening TH is obtained, and the throttle opening control unit B1 shown in FIG.
In step 03, the throttle opening is controlled based on the target throttle opening TH.

The above is the contents of all the processes executed by the timer interrupt. Such processing is executed every time a timer interrupt signal is given, and the throttle opening is controlled.

Although the embodiment of the present invention has been described above, this is merely an example, and the embodiment may be implemented with various improvements. For example, in the above-described embodiment, a device that makes the driver recognize by a warning light, a warning sound, or the like may be provided near the driver's seat when the target throttle opening is corrected by the obstacle handling correction unit.
Thus, it is possible to prevent unnecessary repetition of the accelerator operation by the driver when the target throttle opening is corrected.

[0085]

As described above, according to the present invention,
When the vehicle starts running or re-accelerates from extremely low speed running, if there is a running environment in which there is an obstacle such as another vehicle within a short distance in front of or behind the vehicle, immediately adjust the throttle opening. Since the control for correcting the value to a small value is performed, it is possible to obtain an effect that it is possible to reduce the burden on the driver of unnecessary accelerator operation and the like in controlling the vehicle.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle driving force control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a functional configuration of a throttle opening target value calculation unit in the embodiment.

FIG. 3 is a flowchart showing processing contents of a timer interrupt routine in the embodiment.

FIG. 4 is a flowchart showing a processing content of an operation parameter calculation routine in the embodiment.

FIG. 5 is a flowchart showing processing contents of a correction coefficient calculation routine in the embodiment.

FIG. 6 is a block diagram showing a calculation content in an average vehicle speed calculation routine in the embodiment in terms of hardware.

FIG. 7 is a diagram illustrating a procedure for estimating an intention to accelerate by fuzzy inference in the embodiment.

FIG. 8 is a flowchart showing processing contents of an obstacle correspondence correction coefficient calculation routine in the embodiment.

[Explanation of symbols]

B100 Driving force control device B102 Throttle opening target value calculation unit R401 Target throttle opening calculation routine R402 Correction routine for mountainous curved road (above, calculation means) R403 Obstacle correspondence correction routine R310 Obstacle correspondence correction coefficient calculation routine (above,
SE9 shift position sensor (shift position detecting means) SE2 inter-vehicle distance sensor (distance detecting means)

Claims (1)

[Claims] 1. A driving force control device comprising a calculating means for calculating a target throttle opening corresponding to an accelerator operation and controlling a throttle opening of an engine of a vehicle according to the target throttle opening, wherein the vehicle is in a stopped state. Alternatively, stop state detecting means for detecting that the vehicle is traveling at an extremely low speed, distance detecting means for detecting a distance to an obstacle in front of or behind the vehicle, shift position detecting means for detecting a shift position, and the vehicle. Controlling the throttle opening of the engine when the stop state detecting means detects that the vehicle is in a stopped state or an extremely low speed running state, and the shift position detected by the shift position detecting means belongs to a travel range. The target throttle opening set in the step is corrected to decrease in accordance with the distance detected by the distance detecting means. Driving force control apparatus for a vehicle characterized by comprising the harm was corresponding correction means.