JP2001328454A - Vehicle-to-vehicle distance control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle-to-vehicle distance control device capable of performing appropriate vehicle-to-vehicle distance control even during travel on an upward slope. SOLUTION: This vehicle-to-vehicle distance control device computes the target vehicle speed so as to coincide with the target vehicle-to-vehicle distance, estimates the deviation amount from the moving characteristic of a control object, corrects the target vehicle speed with the estimated deviation amount to set the new target vehicle speed and controls the vehicle speed according to the new target vehicle speed. The vehicle-to-vehicle distance control device determines a value corresponding to the inclination angle of the upward slope on the basis of the estimated deviation amount and corrects a feedback constant for vehicle-to-vehicle distance control basically determined according to the relative speed between a preceding vehicle and one's own vehicle, to a larger value according to the value corresponding to the inclination angle of the upward slope. In the case of controlling in an accelerating direction by the deviation amount during travel on the upward slope, the feedback responsiveness of the vehicle-to-vehicle distance control is improved, so that the speed is rapidly reduced in the case of reaching the set vehicle-to-vehicle distance. A delay in starting to slow down can therefore be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance control device for controlling a vehicle to run while maintaining the inter-vehicle distance from a preceding vehicle.

[0002]

2. Description of the Related Art As prior art of an inter-vehicle distance control device,
For example, there is one described in Japanese Patent Application No. 10-240180 (not disclosed). In this prior art, a deviation amount from a motion characteristic of a control target is estimated (disturbance estimation), and a value obtained by adding a disturbance value to a target vehicle speed is set as a new target vehicle speed.
The system is configured to perform inter-vehicle distance control according to a disturbance estimation value (running resistance or the like).

[0003]

However, since the disturbance estimation is to detect the deviation from the motion characteristic of the normal control target, the normal control target motion characteristic (flat (During road running), and the deviation amount is continuously added, and the acceleration direction is continuously controlled. In such a case, when the own vehicle catches up with the preceding vehicle and the inter-vehicle distance reaches the set value, the target vehicle speed changes in the deceleration direction. There was a risk of getting too close.

The present invention has been made to solve the problems of the prior art as described above, and it is an object of the present invention to provide an inter-vehicle distance control device capable of performing appropriate inter-vehicle distance control even when traveling on an uphill road. .

[0005]

In order to achieve the above object, the present invention is structured as described in the appended claims. That is, in the first aspect, a means for detecting a value corresponding to an inclination angle of an uphill road is provided, and the response of feedback of inter-vehicle distance control determined according to the relative speed between the preceding vehicle and the own vehicle is increased. The correction is made so as to increase the speed according to the value corresponding to the inclination angle of the road.
According to a second aspect of the present invention, the target inter-vehicle distance is set to a large value in accordance with a value corresponding to the inclination angle of the uphill road. According to a third aspect of the present invention, a deviation amount from the motion characteristic of the control target is estimated, and a value corresponding to the inclination angle of the uphill road is determined according to the estimated deviation amount.

[0006]

According to the first aspect of the present invention, when the vehicle is traveling on an uphill road and the control in the acceleration direction is performed based on the deviation amount, the feedback response of the following distance control is performed. Since the vehicle speed is improved, deceleration is quickly performed when the set inter-vehicle distance is reached, so that it is possible to prevent delay in starting deceleration.

In the second aspect, when the vehicle is traveling on an uphill road and the control in the acceleration direction is performed based on the deviation amount, the value of the target inter-vehicle distance is set to be large, so that the deceleration is started earlier. As a result, it is possible to prevent delay of the start of deceleration.

According to the third aspect of the present invention, a value corresponding to the inclination angle of the uphill road is calculated by using the deviation amount (disturbance estimated value) used for correcting the target vehicle speed. There is an effect that there is no need to provide them.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The overall structure of an inter-vehicle distance control device will be described below. FIG. 1 is a block diagram showing the overall configuration of an inter-vehicle distance control device according to the present invention. Hereinafter, FIG.
The configuration and operation of each block shown in FIG. The inter-vehicle distance control unit 105 (portion surrounded by a broken line) includes a microcomputer and its peripheral components. The blocks inside the inter-vehicle distance control unit 105 are obtained by displaying the contents of the calculation by the computer in blocks.

The inter-vehicle distance control unit 105 includes a vehicle speed sensor 1
0, the following distance sensor 15, the following time setting unit 150,
Inter-vehicle distance signal L from vehicle speed control section 500_A(t), relative
Speed signal ΔV (t), own vehicle speed signal V_A(t) etc.
Force, vehicle speed command value V for headway control ^*Calculate (t) and use it
To the vehicle speed control section 500. In the configuration of the vehicle speed control unit 500
This will be described in detail with reference to FIG. Note that (t) is
The sign attached means that the value changes over time.
You. However, (t) is omitted in the drawing.
There is also.

The vehicle speed sensor 10 detects the vehicle speed (hereinafter, referred to as the vehicle speed) _VA (t) of the vehicle from the number of rotations of the tires. Inter-vehicle distance sensor 15, for example, utilizes the laser radar detects a relative speed [Delta] V (t) from the time change of the vehicle distance L _A (t) and the inter-vehicle distance to the preceding vehicle by the reflection wave of light or radio waves The vehicle speed V _A (t) is input from the vehicle speed sensor 10, and the relative speed ΔV (t) and the vehicle speed V
_If the difference from _A (t) is out of the range of, for example, ± 5% × V _A (t) km / h, the object ahead of the vehicle is determined to be the preceding vehicle, and the preceding vehicle flag F is output.

The inter-vehicle time setting section 150 sets the inter-vehicle time d _T (t) by a driver's operation. Here, the inter-vehicle time refers to the time required for the host vehicle to reach the preceding vehicle at the current speed when the preceding vehicle stops. The inter-vehicle time setting unit 150 is configured to select three types of inter-vehicle time by operating a switch that switches between three stages, for example, a long distance, a medium distance, and a short distance. For example, a long distance is 2.2 seconds, a medium distance is 1.8 seconds, a short distance is about 1.4 seconds, and a medium distance of 1.8 seconds is 1 hour / hour.
In the case of 00 km / h, it corresponds to an inter-vehicle distance of about 50 m.

The inter-vehicle distance command value calculation unit 110 calculates the inter-vehicle distance.
A part of the control unit 105 is configured, and as shown in FIG.
Set inter-vehicle time phase advance compensation unit 111 and inter-vehicle distance command value determination
It is composed of a setting unit 112. Set inter-vehicle time phase lead compensation
The unit 111 calculates an inter-vehicle time d._TEnter (t) and enter the previous
Time d_T(t-1) and the current inter-vehicle time d_T(t) is different
In other words, if the driver has changed the
If it is determined, the inter-vehicle time phase advance compensation value d
_{T_HPF}(t) is output. Set to the following formula
5 shows a transfer function of the advance compensator 111. d_{T HPF}(t) = d_T(t) ・ (T₁・ S + 1) / (T
₂・ S + 1) where T₁> T₂  s is a differential operator (the same applies to the following formula), T₁, T₂Is
A time constant arbitrarily set by a designer,₁> T₂When
By doing, the inter-vehicle time d_TAdvance the phase of (t)
Can be.

FIG. 3 shows a set inter-vehicle time phase advance compensator 111.
5 shows the step response of the transfer function of As shown in FIG.
Set inter-vehicle time d _T (t) to inter-vehicle time phase advance compensation unit 11
A phase lead compensation as shown by a transfer function of 1 is performed. In other words, when the driver changes the setting of the inter-vehicle time, the inter-vehicle time d corresponding to the intermediate distance, for example, as in the example shown in FIG.
If you change the setting to the inter-vehicle time d _{T S} from _TM corresponding to the time headway d _TL or short-range corresponding to a long distance, a new inter-vehicle time to the target d _TL or d temporarily time headway than _TS Is increased (larger when the inter-vehicle time is changed to a large value, and smaller when the inter-vehicle time is changed to a small value), and then the target inter-vehicle time d _TL or d _TS
To converge. With this configuration, when the driver changes the setting of the inter-vehicle time, control can be performed so as to promptly respond to the driver's will.

The inter-vehicle distance command value determining section 112 calculates a time-phase lead compensation value d based on the own vehicle speed V _A (t), the relative speed ΔV (t) and the inter-vehicle time arbitrarily set by the driver.
_{From T_HPF} (t), the following distance command value L is calculated according to the following equation.
^* Calculate (t). L ^* (t) = {V _A (t) + ΔV (t)} · d
_{T_HPF} (t) The inter-vehicle distance command value L ^* (t) is equal to the own vehicle speed V as described above.
_This is a value obtained by multiplying a value obtained by adding _A (t) and the relative speed ΔV (t) by a time phase advance compensation value d _{T_HPF} (t). Therefore, when the inter-vehicle time is changed as described above, the driver temporarily increases the amount of change in the inter-vehicle time and then converges to the target inter-vehicle time as shown in the characteristic of FIG. The distance between vehicles changes rapidly after the operation of. Therefore, for example, after determining that the driver is too close to the preceding vehicle and changing the setting so as to increase the inter-vehicle time, the inter-vehicle distance changes immediately. The fear of giving anxiety is eliminated. Next, the target inter-vehicle distance calculating unit 120 of FIG. 1, the preceding vehicle flag F from the inter-vehicle distance sensor 15, enter the relative speed [Delta] V (t) and the headway distance L _A (t), when the recognized preceding vehicle relative speed [Delta] V (F) and the headway distance L _a and (F) as the initial value of the target relative speed ΔV _T (t) and the target inter-vehicle distance L _T (t), and inputs the inter-vehicle distance command value L ^* (t) Inter-vehicle distance L _T (t) and target relative speed ΔV
_T (t) is calculated by the filter shown in the following (Equation 1).
calculate.

[0016]

(Equation 1)Where ω_nTIs the natural frequency of the target inter-vehicle distance response.
Value set by the designer_TIs the target inter-vehicle distance response
Is a damping coefficient that is set arbitrarily by the designer.
For the formula 1), the inter-vehicle distance command value L^*Enter (t), eye
Distance between marked cars L _TThe transfer function when (t) is the output is
It is shown by the above equation. L_T(t) = ω_nT ²・ E^{-LV · s}・ L^*(t) / (s
²+ 2ζ_T・ Ω_nT・ S + ω_nT ²The pre-compensation vehicle speed command value calculation unit 130 includes a vehicle speed control unit 500.
Transfer characteristic G neglecting the dead time_V(s) 'G_V(s) '= 1 / (T_V.S + 1) and the inverse of the transfer function consisting of the product of the integrator and L
_T(t) from the product with the transfer function ignoring the dead time
And V expressed by the following equation_C(t) is calculated. V_C(t) = ω_nT ²・ S (T_V・ S + 1) ・ L^*(t) /
(S²+ 2ζ_T・ Ω_nT・ S + ω_nT ²Also, from the state space representation using equation (1), V_C(t)
Is obtained as shown in the following (Equation 2).

[0017]

(Equation 2) However, T _V is the time constant used in the transfer characteristic of the vehicle speed control section 500.

The inter-vehicle control vehicle speed command value calculation unit 140 is a real vehicle
Distance L_A(t) and actual vehicle speed V_A(t) and actual relative speed
ΔV (t) and target inter-vehicle distance L_T(t) and target relative speed
ΔV _T(t) and the corrected vehicle speed command value V_C(t) and later
Feedback constant f_L, F _VMore, the following formula
Your vehicle speed command value V^*(t) is calculated. V^*(t) = V_A(t) + ΔV (t) −V_C(t)-｛L_T
(t) -L_A(t)｝ ・ f_L − ｛ΔV_T(t) -ΔV
(t)｝ ・ f_V  The inter-vehicle control feedback characteristic determining unit 300 calculates the inter-vehicle distance.
L_A(t), relative speed ΔV (t) and set headway
Interval d_T(t) and input the feedback constant f _L, F_V
Is calculated.

Hereinafter, a method for determining the feedback constants f _L and f _V will be described with reference to FIG. FIG. 4 is a block diagram of the inter-vehicle control feedback characteristic determining unit 300. The inter-vehicle control feedback characteristic determining unit 300 is a feedback system damping coefficient determining unit 3 of the inter-vehicle distance control unit 105.
10, a feedback system damping coefficient correction unit 311, a feedback system natural frequency determination unit 320, a feedback system natural frequency first correction unit 330, a feedback system natural frequency second correction unit 331, and a feedback constant determination unit 340. I have.

This inter-vehicle control feedback characteristic determining unit 3
A block diagram of a 00, is represented by the transfer function G _DB from the target inter-vehicle distance L _T (t) to actual headway distance L _A (t), as shown in the following equation. _{G DB (s) = {ω} nDB 2 (T VB · s + 1)} / {s
^{_{2 + 2ζ nDB · ω nDB ·}} s + ω nDB 2} _{However, ζ nDB = (f V +1} ) / 2√ (f L · T V): damping coefficient of the inter-vehicle control feedback system _{ω nDB = √ (f L /} T V) : Natural frequency of the inter-vehicle control feedback system T _VB = f _L / T _V : value equivalent to the zero point of the inter-vehicle control feedback system T _V : time constant of the vehicle speed feedback control in the vehicle speed control unit 500 The feedback system damping coefficient determination unit 310 Relative speed Δ
V (t) is input, and FIG.
The inter-vehicle control feedback system damping coefficient ζ _nDB is determined from the map shown in FIG. As shown, _ΔnDB is constant even when the relative speed changes. In order to prevent oscillation and improve responsiveness, set the value to 1 (ζ
_This is because it is optimal to set critical braking when _nDB = 1).

Feedback system damping coefficient determining section 320
Inputs the relative speed ΔV (t), and determines the natural frequency ω _nDB of the headway control feedback system according to the map shown in FIG. 5B according to the relative speed ΔV (t). FIG. 5 (b)
The characteristic shown in (1) is that when the absolute value of the relative speed ΔV (t) is small, the natural frequency ω _nDB is reduced to control slowly, and when the absolute value is large, the natural frequency ω _nDB is increased. The control is fast so as not to occur.

Feedback system natural frequency first correction unit 3
30 is the actual inter-vehicle distance L_A(t) is set in advance as a variable
From the map shown in FIG.
Natural frequency ω of_nDBCorrection coefficient C for correcting_D1Seeking
The natural frequency ω_nDBAnd correct the natural vibration after the correction.
Number ω_nDBC1Is output. That is, ω_nDBC1Is
It is shown by the following equation. ω_nDBC1= C_D1・ Ω_nDB  Correction coefficient C_D1Is the distance between vehicles, as is clear from FIG.
Is shorter than a first predetermined value (for example, about 20 m),
Correction coefficient C_D1As a value of 1 or more, the natural frequency ω
_nDBResponsiveness of inter-vehicle distance control by increasing
Is going to be faster. In addition, the distance between vehicles is the second place
If it is longer than a fixed value (for example, about 90 m), the correction coefficient C
_D1Is less than 1 and the natural frequency ω_nDBSmaller
Therefore, the responsiveness of the following distance control is made slow.

As described above, the natural frequency depends on the distance between vehicles.
ω_nDBIs corrected, and if the inter-vehicle distance is large,
Power ω_nDBAnd if the inter-vehicle distance is small,
Frequency ω_nDBTo increase the distance between vehicles.
If the response is too slow,
Steep even if the relative speed greatly changes due to calculation error
Prevent improper control and give the driver an uncomfortable feeling
Disappears. In addition, when the inter-vehicle distance is small, the response
The vehicle is slightly faster than the vehicle speed
If you cut in front of your vehicle, immediately
Since it opens, the driver does not feel uneasy. Fi
The feedback system natural frequency second correction unit 331 calculates the headway time.
d_T(t) and the natural frequency ω of the headway control feedback system
_nDBC1And the last inter-vehicle time d _T(t-1)
And this time d_T(t) is different, that is,
If it is determined that the driver has changed the setting
Is the correction coefficient C for one second._D2Preset value
By changing from 1 to 1.5, the
Temporarily increase the natural frequency of the feedback system. Through
Normally, correction coefficient C_D2Is 1 and the time between cars setting is
Only take a value greater than 1 if it has changed.
To temporarily reduce the natural frequency of the headway control feedback system.
Bigger so that you can change the inter-vehicle time quickly
That's why. Corrected natural frequency ω_nDBCIs shown by the following formula
Is done. ω_nDBC= C_D2・ Ω_nDBC1  The feedback system natural frequency second correction unit 33
1, the natural frequency of the inter-vehicle distance feedback system (gay
Responsiveness is improved by increasing
However, in this configuration, if the preceding vehicle behaves suddenly,
May cause a slight deterioration in ride comfort.
There is. In that regard, the inter-vehicle distance command value determination unit 112 explains
As mentioned, when the headway time changes, a new car
Time d _TLTemporarily increase the value of the inter-vehicle time.
Is made smaller, and then the target inter-vehicle time d_TLConverges to
When configured to allow
There is no fear of responding. Next, the fee which is the main point of the present invention
The feedback system attenuation coefficient correction unit 311 will be described. H
The feedback system damping coefficient correction unit 311 includes the vehicle speed control unit 5
The disturbance calculated by the drive torque command value calculation unit 530 of 00
Estimated value d_VEnter (t) and reduce feedback
From the decay coefficient determination unit 310_nDBAnd the disturbance estimate
d_VFrom (t), the road surface gradient amount φ_AEstimate (t). concrete
As shown in FIG. 7, the estimated disturbance value d_V(t) is negative
If it is an uphill road, if it is positive,
Surface gradient φ_AFind (t). And based on FIG.
Correction coefficient C_D3And reduce the inter-vehicle control feedback system.
Decay coefficient ζ_nDBTo correct the attenuation coefficient ζ_nDBCThe value of
decide. That is, the damping coefficient ζ_nDBCIs shown by the following formula
It is. ζ_nDBC= Ζ_nDB・ C_D3 C_D3Is, as is clear from FIG. 8, the road surface gradient amount φ_A
If (t) is within a predetermined range, C_D3And 1
Surface gradient φ_AAs the absolute value of (t) increases, C_{D 3}The value of
It is larger than 1.

The feedback constant determining unit 340 determines the distance between vehicles.
Damping coefficient of control feedback system ζ _nDBCAnd natural vibration
Number ω_nDBCAnd the feedback constant f_L, F_V
Is calculated from the following equation. f_L= Ω_nDBC ²・ T_V  f_V= 2ζ_nDBC・ Ω_nDBC・ T_V-1 As a result, the following distance L_AAs (t) is shorter, the correction coefficient C
_D2Becomes smaller and the natural frequency ω_nDBGrows larger
And the feedback coefficient f_L, F_VGrow together,
Deceleration becomes faster. At this time, the inter-vehicle distance L_A(t) is short
The natural frequency ω_nDBCIncrease the feedback
Check coefficient f_L, F_VInstead of increasing the
The headway control feedback constant f_LCorrect
May be. The correction coefficient C increases as the inclination of the road increases.
_D3Increases, and the damping coefficient ζ_{n DBC}Also getting bigger
Feedback constant f_VAnd the deceleration is faster
You.

The characteristic vibration of the inter-vehicle control feedback system
Powerζ_nDBInstead of changing the distance command
Target inter-vehicle distance L of calculation unit 110^*(t) may be increased
No. Specifically, the inter-vehicle distance command value calculation unit 110 calculates the vehicle speed.
Drive torque command value calculation section 530 of control section 500 calculates
Estimated disturbance d_VEnter (t) and figure from the disturbance estimate
Road surface gradient φ from 7_A(t) is estimated and the map shown in FIG.
Correction coefficient C_D4(> 1) is determined and the distance between vehicles shown in FIG. 2 is determined.
L in distance command value determination unit 112^*(t)
Positive coefficient C_D4And the target inter-vehicle distance L^*Calculate (t)
May be. That is, L^*(t) = [V_A(t) + ΔV (t)] · d_T・ C_D4  In this case, a disturbance estimation value d representing the inclination angle of the road surface
_VThe correction coefficient C increases as (t) increases._D4Became big
The target inter-vehicle distance L^*(t) increases. Therefore,
Speed starts earlier.

[0026] As described above, corrected according to the estimated disturbance value _{d V} (t) representing the like inclination angle of the road surface coefficient _{C D3} and _{C D4}
If the control is performed in the acceleration direction based on the amount of deviation while traveling on an uphill road, the response of the inter-vehicle distance control is improved, or the value of the target inter-vehicle distance is set. Is set to be large, when the set inter-vehicle distance is reached, deceleration is performed immediately, or deceleration is started early, so that it is possible to prevent delay in starting deceleration even during climbing a hill. Also, the disturbance estimation value d
_Since the inclination of the uphill road is calculated using _V (t), it is not necessary to provide a special sensor such as an inclination angle sensor. The above is the description of the gist of the present invention.

Next, the vehicle speed control section 500 will be described. FIG. 10 is a block diagram showing the overall configuration of the vehicle speed control device. Hereinafter, the configuration and operation of each block in FIG. 10 will be described. First, when a system switch (not shown) is turned on, the power of the entire apparatus is turned on, and the apparatus enters a standby state. When the set switch 20 is turned on in this state, the control is started. The vehicle speed control section 500 (portion surrounded by a broken line) is composed of a microcomputer and its peripheral parts. Note that the blocks inside the vehicle speed control section 500 are obtained by displaying the contents of the calculation by the computer in blocks.

In the vehicle speed control unit 500, the vehicle speed command value determination unit 510 determines the vehicle speed command value V every 10 ms.
_COM (t) is calculated. In addition, the sign attached with (t) means that the value changes with time. However, (t) may be omitted in the drawings.

The vehicle speed command maximum value setting unit 520 includes a set speed
Own vehicle speed V when switch 20 is pressed_A(t) is the speed finger
Command maximum value V_SMAX(Target vehicle speed). What
Contact, vehicle speed V_A(t) indicates the rotation of the tire by the vehicle speed sensor 10.
It is the actual speed of the vehicle detected from the number. Also,
The vehicle speed command maximum value V is set by the set switch 20 as shown in FIG.
_SMAXCoast switch 30 is set once after
Each time the button is pressed, the vehicle speed command maximum value setting unit 520 displays the vehicle speed finger.
Command maximum value V_SMAXTo a lower value by 5 km / h
You. That is, when pressed n times, n × 5 km / h (pressed and held
In this case, if the pressing time is t, for example, t / 10 m
s × 5 km / h). Also,
The vehicle speed command maximum value V is set by the set switch 20 as shown in FIG.
_SMAXIs set, the acceleration switch 40
Every time is pressed, the vehicle speed command maximum value setting unit 520
Vehicle speed command maximum value V_SMAXTo a higher value by 5 km / h.
Set. That is, when pressed n times, n × 5 km / h (press and hold
In the case of a digit, if the pressing time is t, for example, t / 1
0 ms × 5 km / h).

Next, the lateral G vehicle speed correction amount calculating section 580 calculates the steering angle θ of the steering wheel output from the steering angle sensor 100.
(t) and the own vehicle speed V _A (t) are input, and a vehicle speed correction amount V _SUB (t) for correcting a later-described vehicle speed command value in accordance with a lateral acceleration (hereinafter, referred to as a lateral G). Calculate. Note that the lateral G vehicle speed correction amount calculation unit 580 is described in detail in FIG.
, A steering angle signal low-pass filter (hereinafter, referred to as a steering angle signal LPF unit) 581, a lateral G calculation unit 582,
It is composed of a vehicle speed correction amount calculation map 583.

First, the steering angle signal LPF section 581 is provided for the own vehicle.
Speed V_A(t) and the steering angle θ (t), and input the steering angle LPF value.
θ_LPF(t) is calculated. θ_LPFIs represented by the following equation
It is. θ_LPF(t) = θ (t) / (TSTR · s + 1) where s is a differential operator (the same applies to the following equation). Here, the time constant TSTR of the LPF is TSTR = 1 /
(2π · fc), the cutoff frequency of the LPF
The number fc is the vehicle speed V as shown in FIG. _A(t)
Determined by a map of the cutoff frequency fc.
In this map, the cutoff frequency fc decreases as the vehicle speed increases.
Is set well. For example, 100 compared to 50 km / h
km / h takes a lower value.

The lateral G calculator 582 calculates the steering angle LPF value θ.
_{The LPF} (t) and the own vehicle speed _VA (t) are inputted, and the value Y _G (t) of the lateral G is calculated according to the following equation. Y _G (t) = {V _A (t) ² · θ _LPF (t)} / {N · W ·
[1 + A · _VA (t) ² ] where W is the wheelbase of the vehicle, N is the steering gear ratio, and A is the stability factor.

In the above equation, the lateral G is detected from the steering angle.
The yaw rate sensor is used.
Apply low-pass filter to late レ (t) to detect lateral G
In this case, the following equation may be used. Y_G(t) = V_A(t) ・ ψ_LPF  ψ_LPF= Ψ (t) / (T_YAW・ S + 1) where T_YAWIs the time constant of the low-pass filter,
Own vehicle speed V_AThe larger the value of (t), the larger the value
You.

The vehicle speed correction amount calculation map 583 includes a vehicle speed correction amount V for correcting a vehicle speed command value according to the lateral G.
_SUB (t) is calculated. The vehicle speed correction amount V _SUB (t) is
A predetermined vehicle speed command value change amount limit value [for example, 0.021 (km / h) / 10 (ms)] is added to a correction coefficient determined by the lateral G.
= 0.06G]. The value of the vehicle speed command value change amount limit value is equal to the maximum value of the vehicle speed command value change amount ΔV _COM (t) shown in FIG. V _SUB (t) = correction coefficient × 0.021 (km / h) / 1
0 (ms) As will be described later, when calculating the vehicle speed command value V _COM (t) which finally becomes a value for controlling the vehicle speed, the above-described vehicle speed correction amount V _SUB (t) is added as a subtraction term. ing. Thus the larger the value of the vehicle speed correction quantity _{V SUB} (t), command vehicle speed _{V CO M} (t) will be limited.

As shown in FIG. 13, the above-mentioned correction coefficient increases as the value Y _G (t) of the horizontal G increases. This is because the greater the lateral G, the greater the restriction on the change in the vehicle speed command value V _COM (t). However, as shown in FIG. 13, when the lateral G is 0.1 G or less, it is determined that it is not necessary to correct the vehicle speed command value, and the correction coefficient is set to zero. Also,
When the horizontal G is 0.3 G or more, the value is a value that does not occur in normal use. In the above, the correction coefficient is fixed (for example, 2).

As will be described in detail later in the vehicle speed command value determination unit 510, when the target vehicle speed is increased by operating the accelerator switch 40, that is, when acceleration is requested, the current vehicle speed V _A (t) is added with the vehicle speed command value change amount ΔV _COM (t), and the vehicle speed correction value V
_The vehicle speed command value V is obtained by subtracting _SUB (t).
_COM (t) is calculated. Therefore, if the vehicle speed command value change amount ΔV _COM (t) is larger than the vehicle speed correction value V _SUB (t), the vehicle is accelerated, and if it is smaller, the vehicle is decelerated. As described above, the vehicle speed correction value V _SUB (t) corresponds to the vehicle speed command value change amount limit value (the maximum value of the vehicle speed command value change amount) in FIG.
For example, when the vehicle speed command value change amount limit value is equal to the vehicle speed command value change amount, the correction coefficient is 1 (Y _G ( t)
= 0.2), the acceleration and deceleration are equal, and the current vehicle speed is maintained. That is, in this example, when the value Y _G (t) of the lateral G is smaller than 0.2, the acceleration is performed, and when it is large, the acceleration is decelerated. When the target vehicle speed is reduced by operating the coast switch 30, that is, when deceleration is requested, the current vehicle speed _{VA is used.}
The vehicle speed command value V _COM (t) is calculated by subtracting the vehicle speed command value change amount ΔV _COM (t) and the vehicle speed correction value V _SUB (t) from (t). Therefore, in this case, the vehicle always decelerates, but the degree of deceleration increases as the vehicle speed correction value V _SUB (t) increases, that is, as the lateral G increases. Note that the above value 0.021 (km / h) / 10 (ms) for the vehicle speed command value change amount limit value is:
These values are for use on expressways.

As described above, the vehicle speed correction value V
_SUB (t) is obtained by the product of the correction coefficient corresponding to the lateral G and the vehicle speed command value change amount limit value. When the lateral G increases, the value of the subtraction term (vehicle speed correction value) increases and the lateral G does not increase. The vehicle speed is controlled as follows. However, as described in the steering angle signal LPF unit 581 in FIG.
Since the cutoff frequency fc is lowered, the time constant TSTR of the LPF increases, and the steering angle LPF value θ
_LPF (t) decreases, and the lateral G estimated by the lateral G calculation unit 582 also decreases. As a result, the vehicle speed correction value V _SUB (t) obtained via the vehicle speed correction amount calculation map 583.
Becomes smaller, it is difficult to correct the vehicle speed command value (correction in the direction of decreasing acceleration) by the steering angle.

The characteristic of the natural frequency ω _nSTR of the vehicle response to the steering angle is expressed by the following equation. ω _nSTR = (2W / V _A ) √ [Kf · Kr · (1 + A ·
V _A ² ) / m _V · I] where Kf and Kr are the cornering powers of the front and rear wheels.
(One wheel min), W is wheel base, _{m V} is the vehicle mass, A
Is a stability factor, and I is a vehicle yaw moment of inertia. As shown in FIG. 14, the characteristic of the natural frequency ω _nSTR is such that the natural frequency ω _nSTR decreases as the vehicle speed increases and the vehicle responsiveness to the steering angle deteriorates, whereas the natural frequency ω _nSTR decreases as the vehicle speed decreases. It can be understood that the vehicle response to the steering angle is improved. That is, in a high vehicle speed range, lateral G is less likely to occur even when steering is performed, and in a low vehicle speed range, lateral G is likely to occur even with a small amount of steering. Therefore, as shown in FIG. 12, by decreasing the cut-off frequency fc in the higher vehicle speed range, the response is slowed, and the correction of the vehicle speed command value by the steering angle is hardly performed. Next, the vehicle speed command value change amount determination unit 590 in FIG. 10 determines the vehicle speed _VA (t) and the vehicle speed command maximum value V
Based on the absolute value of the deviation from _SMAX , a vehicle speed command value change amount ΔV _COM (t) is calculated using a map shown in FIG. In this map, the absolute value of the deviation is within a certain range (FIG. 15).
In the middle range B), the vehicle speed command value change amount ΔV _COM (t) is increased as the absolute value is increased so as not to exceed the acceleration limit value α described in the vehicle speed control suspension determination unit 610, and acceleration or acceleration is performed as quickly as possible. Slow down. Then, the vehicle speed command value change amount ΔV _COM (t) is made small so that the sense of acceleration is not impaired as the absolute value of the deviation becomes smaller, so that the vehicle speed command maximum value _VSMAX is not overshot. In a range where the absolute value of the deviation is large (a range A in FIG. 15), a value not exceeding the acceleration limit value α is set to a constant value (for example, 0.06G). Further, in a small range (range C in FIG. 15), a constant value (for example, 0.03G) is set.

Further, the vehicle speed command value change amount determination unit 590
Is output from the lateral G vehicle speed correction amount calculation unit 580.
Vehicle speed correction value V_SUB(t) is monitored and the vehicle speed is corrected
Value V _SUBThe value of (t) has changed from zero to non-zero once
If it returns to zero again later, driving on a curved road ends.
And the vehicle speed V_A(t) and vehicle speed command
Maximum value V_SMAXIs equal to
You. If it is determined that the curve has ended,
Own vehicle speed V_A(t) and vehicle speed command maximum value V_SMAXDeviation from
Vehicle speed command value change amount using FIG. 15 based on the absolute value of
ΔV_COMInstead of determining (t), the curve ends.
Own vehicle speed V when it is determined that_AVehicle speed command from (t)
Value change amount ΔV_COM(t) is determined. The characteristics at that time
Characteristics having the same tendency as in FIG. 15 are used. That is, the figure
The horizontal axis of | 15 is | V_A(t) -V_SMAXInstead of |
And own vehicle speed V_AMap (not shown) changed to (t)
Used, own vehicle speed V_A(t) is smaller, the vehicle speed command value change amount
ΔV_COM(t) is a characteristic set to a small value.
It has become sex. This processing is performed based on the vehicle speed V.
_A(t) and vehicle speed command maximum value V_SMAXEnds when
Complete.

It should be noted that the vehicle speed command value change amount ΔV from the actual vehicle speed V _A (t) at the time when it is determined that the curve has been completed.
Instead of the above-described example to determine the _COM (t), when the vehicle speed correction value V _{SU B} (t) becomes a non-zero value, it determines the curved road traveling is started, vehicle speed V _A at that time (sta
rt) is stored in advance, and a difference ΔV _A = V _A (s) from the own vehicle speed V _A (end) when it is determined that the curved road is ended.
tart) -V _A (end) (ie, the vehicle speed command value change amount ΔV from the magnitude of the vehicle speed command value correction).
_COM (t) may be determined. The characteristics at this time are shown in FIG.
The characteristic which shows the reverse tendency is used. In other words, the horizontal axis of FIG. _{15, | V A (t)} -V SMAX | instead of, using a map (not shown) for changing the speed difference [Delta] V _A, the vehicle speed difference Δ
The vehicle speed command value change amount ΔV _COM (t) is set to be smaller as _VA is larger. This process ends when the vehicle speed V _A (t) becomes equal to the vehicle speed command maximum value V _SMAX .

When traveling on a curved road, the vehicle speed command value is corrected so that the value of the lateral G does not become excessively large, so that the vehicle speed generally decreases. Therefore, as described above, after traveling on a curved road and the vehicle speed drops, the vehicle speed V _A (t) at the end of the curved road or at the start and end of the curved road (the vehicle speed is corrected by correcting the vehicle speed command value). Vehicle speed difference ΔV before and after
_The vehicle speed command value change amount ΔV according to the magnitude of _A
COM (t) is changed.

[0042] When either the vehicle speed is low or the vehicle speed difference [Delta] V _A is large when the curved road terminates, small radius of curvature of the curved road (curve tight) is estimated to fell vehicle speed for. When the curved road is continuous (for example, an S-shaped curve), there is a high possibility that the above-described situation will occur. Therefore, if either the vehicle speed at the curved road ends is low or the vehicle speed difference [Delta] V _A is large, to reduce the acceleration of the vehicle speed control by the vehicle speed command value to reduce the vehicle speed command value change amount ΔV _COM (t). Accordingly, in a continuous curve (S-shaped road), a large acceleration is not performed every time the vehicle turns around the curve. Similarly, if either the vehicle speed is high, or the vehicle speed difference [Delta] V _A is small at the curved road terminates, it is determined to be a single curve, the vehicle speed command value change amount Δ
V _COM (t) is increased. As a result, since the vehicle is accelerated immediately after the end of a single curve, there is no danger that the acceleration will be slow and the driver will feel uncomfortable.

Further, as described above, the vehicle speed command value change amount is determined.
In the section 590, basically, the actual vehicle speed V _A(t)
Vehicle speed (in this case, the vehicle speed command maximum value V
_SMAXIf the deviation from) is large, the vehicle speed command value change amount
ΔV_COMIs configured to be larger. Accordingly
The signal from the inter-vehicle distance control unit 105 shown in FIG.
Vehicle is following the preceding vehicle based on the
In the situation where the set vehicle speed and the actual vehicle speed in the distance control are different
If the vehicle was running, the changed set vehicle speed and actual vehicle speed
Vehicle speed command value change amount ΔV according to the deviation of_COM(t) is set
Is determined. In other words, the set vehicle speed before change and the set vehicle speed after change
Even if the speed deviation is small, the actual vehicle speed and the
If the deviation of the set vehicle speed is large, the vehicle speed command value change amount ΔV
_COM(t) is a large value. This allows the driver
Accelerate with the desire to reduce the set vehicle speed
Can be.

Next, a vehicle speed command value determining section 510 shown in FIG.
Is the vehicle speed V_A(t), vehicle speed correction value V _SUB(t), vehicle speed
Command value change amount ΔV_COM(t) and vehicle speed command maximum value V
_{SMA X}And the vehicle speed command value V
_COM(t) is calculated. (1) Vehicle speed command maximum value V_SMAXIs the vehicle speed V_A(t)
Larger, that is, the acceleration switch 40
(Or the resume switch)
If there is V_COM(t) = min [V_SMAX, V_A(t) + ΔV
_COM(t) -V_SUB(t)] That is, the vehicle speed command maximum value V_SMAXAnd V_A(t) + ΔV
_COM(t) -V_SUBSelect the smaller of (t)
And vehicle speed command value V_COM(t). (2) V_SMAXAnd V_AIf (t) are equal, that is,
When maintaining a constant vehicle speed V_COM(t) = V_SMAX-V_SUB(t) That is, the vehicle speed command maximum value V_SMAXFrom the vehicle speed correction value V
_SUB(t) is subtracted and the vehicle speed command value V_COM(t)
You. (3) Maximum vehicle speed command value V_SMAXIs the vehicle speed V_A(t)
Smaller, that is, when the coast switch 30 is operated.
When there is a deceleration request due to_COM(t) = max [V_SMAX, V_A(t) -ΔV
_COM(t) -V_SUB(t)] That is, the vehicle speed command maximum value V_SMAXAnd V_A(t) -ΔV
_COM(t) -V_SUBSelect the larger of (t) and
And vehicle speed command value V_COM(t).

However, the vehicle speed command value determining unit 510 is not shown in FIG.
The vehicle speed command value V ^* (t) for inter-vehicle control and the preceding vehicle flag F from the inter-vehicle distance sensor 15 are input from the inter-vehicle distance control unit 105 shown in FIG. (4) When the preceding vehicle flag F is input When the preceding vehicle flag F is input, the vehicle speed command value V ^* (t) for inter-vehicle control is compared with the vehicle speed command maximum value _VSMAX, and the smaller value is obtained. Is the vehicle speed command value V _C (t), and V
_COM (t) is calculated by the following equation. V _COM (t) = V _C (t) −V _SUB (t) The vehicle speed command value V _COM (t) is determined as described above, and the vehicle speed is controlled in accordance with this.

Next, the drive torque command value calculation section 530
Vehicle speed command value V_COM(t) and own vehicle speed V_AEnter (t),
As shown below, the drive torque command value d_FC(t)
Calculate. FIG. 16 shows a driving torque command value calculating unit 53.
FIG. 3 is a block diagram illustrating an example of a configuration of a 0. First, the speed finger
Remarks V_COM(t) as input, and own vehicle speed V_AOutput (t)
Transfer characteristic G_V(s) can be expressed by the following equation.
it can. G_V(s) = 1 / (T_V・ S + 1) ・ e^{(-Lv · s)}  Where T_VIs the first-order lag time constant, L_VIs the powertrain
This is the dead time due to the delay of the system.

The vehicle model to be controlled is modeled by using the drive torque command value d _FC (t) as an operation amount and the own vehicle speed V _A (t) as a control amount. It can be represented by a simple linear model shown in the following equation. _{V A (t) = 1 /} (m V · Rt · s) e (-Lv · s) ·
d _FC (t) However, Rt is the effective radius of rotation of the tire, _{m V} is vehicle mass. As described above, a vehicle model that receives the drive torque command value d _FC (t) and outputs the own vehicle speed _VA (t) has a 1 / s form, and thus has an integral characteristic.

[0048] Incidentally, the dead time L _V also included, and nonlinear characteristic values of dead time L _V by an actuator and the engine to be used to change, such as described later approximated by delay of the power train system to the characteristics of the controlled object By using the disturbance estimator based on the zeroing technique, a vehicle model that receives the drive torque command value d _FC (t) and outputs the own vehicle speed _VA (t) can be represented by the same equation as above.

Here, the vehicle speed command value V_COMEnter (t)
And own vehicle speed V_A(t) is the output of control
The response characteristic is set to a predetermined first-order delay T_VAnd dead time L_VRequired
Transfer characteristic G_VWhen matching the characteristics of (s),
C as shown in 16₁(s), C ₂(s) and C
₃Using (s), it can be determined as follows.
Where C₁(s), C₂(s) uses approximate zeroing method
Disturbance estimator, and the effects of disturbances and modeling errors
Is a compensator that works to suppress₃(s) is the model
5 shows a compensator based on a matching method. Compensator C₁(s) = e^{(-Lv · s)}/ (T_H・ S + 1) Compensator C₂(s) = (m_V・ Rt · s) / (T_H・ S +
1) At this time, the disturbance estimation value d_V(t) is d_V(t) = C₂(s) · V_A(t) -C₁(s) · d_FC
(t).

Further, ignoring the dead time of the controlled object,
Model Model G_V(s) is the time constant T_VPrimary low-pass fill
Compensator C₃(s) is the following constant
You. Compensator C₃(s) = m_V・ Rt / T_V  Above C₁(s), C₂(s), C₃By the compensator of (s)
Drive torque command value d_FC(t) is calculated by the following equation
Is done. d_FC(t) = C₃(s) · ｛V_COM(t) -V
_A(t)｝-｛C₂(s) · V_A(t) -C₁(s) · d
_FC(t)｝ The above drive torque command value d_FCdrive based on (t)
Control Luke. That is, as shown in FIG.
Using the measured engine non-linear steady-state characteristic map,
Luc command value d_FC(t) shows the actual driving torque d._FA(t) one
Calculate the throttle opening command value to match
If the negative driving torque of the engine is not enough,
And make up to compensate with brakes. Thus, the slot
To control the tor opening, transmission, and brakes
More linearized engine non-linear steady-state characteristics
You.

When the continuously variable transmission 70 has a fluid converter with lock-up, the continuously variable transmission 7
Enter the lockup condition signal LU _S 0 controller, it time when it is determined that the lockup state by a constant T _{H (C 1 (s} in Fig. 16), C
₂ (described in the denominator of (s)). As a result, the vehicle speed control feedback correction amount (correction coefficient of a feedback loop for maintaining a desired response characteristic) is reduced, and can be adjusted to the response characteristic of a controlled object that is delayed at the time of unlocking as compared with the time of lockup. The stability of the vehicle speed control system is ensured both when the vehicle is up and when the vehicle is unlocked.

In the driving torque command value calculating section 530 shown in FIG. 16, the designer has set a compensator C ₁ (s) and a compensator C ₂ (s) for compensating the transfer characteristic of the controlled object. Although the compensator C ₃ (s) for achieving the response characteristic has been configured, as shown in FIG. 21, a pre-compensator C 3 for compensating for an arbitrary response characteristic determined by the designer.
_F (s), a reference model calculation unit C _R (s) for calculating an arbitrary response characteristic determined by the designer, and a reference model calculation unit C
_R (s) deviation from response characteristics (target vehicle speed-own vehicle speed)
May be constituted by a feedback compensator C ₃ (s) ′ for compensating for

The pre-compensator C _F (s) has a vehicle speed command value V
_In order to achieve the transfer function G _V (s) of the actual vehicle speed _VA (t) with respect to _COM (t), the reference drive torque command value d _FC1 (t) is calculated using a filter expressed by the following equation. . d _FC1 (t) = m _V · _RT · s · V _COM (t) / (T
_V · s + 1) The reference model calculation unit C _R (s) converts the target response V _T (t) of the vehicle speed control system into the transfer function G _V (s) and the vehicle speed command value V
Calculate from _COM (t). That is, V _T (t) = G _V (s) · V _COM (t).

Feedback compensator C₃(s) ’is the goal
Response V_T(t) and actual vehicle speed V_A(t)
The drive torque command value to eliminate this deviation.
Positive amount d_V(t) 'is calculated. That is, d_V(t) ’is
Is shown by the following equation. d_V(t) '= [(K_P・ S + K_I) / S] [V_T(t) −
V_A(t)] where K_PIs the feedback compensator C₃(S) ’ratio
Example control gain, K_IIs the feedback compensator C
₃(S) '. In addition, drive torque
Command value correction amount d_V(t) 'is the disturbance inference described with reference to FIG.
Constant value d_V(t). At this time, lock-up
State signal LU_SIs determined to be unlocked by
Correction amount d if rejected_V(t) 'is calculated. sand
, D_V(t) '= [(K_P’· S + K_I') / S] [V_T(t)
-V_A(t)]. Where K_P’<K_P  K_I’<K_I  Therefore, the feedback gain becomes smaller. did
Therefore, the drive torque command value d_FC(t) is the reference drive
Luc command value d_FC1(t) and drive torque command value correction amount d
_VFrom (t) ', d_FC(t) = d_FC1(t) + d_V(t) '. In this way, compared to the time of lock-up
When locking up, reduce the feedback gain
Change speed of the drive torque command value correction amount is low
The lockup time is slower than the lockup time.
Can be matched to the response characteristics of the controlled
Vehicle speed control system for both lock-up and unlock-up
Stability is ensured.

Next, the actuator drive system shown in FIG. 10 will be described. The shift command value calculation unit 540 receives the drive torque command value d _FC (t), the own vehicle speed _VA (t), the output of the coast switch 30 and the output of the accelerator pedal sensor 90, and receives the shift command value DRATIO as follows. (t) is calculated and output to the continuously variable transmission 70. (1) when off the coast switch 30 on the basis of the vehicular velocity _{V A} (t) and command drive torque _{d FC} (t), the throttle opening estimation map from the throttle opening estimation value _{TVO ESTI} as shown in FIG. 18 Is calculated.
Next, the estimated throttle opening TVO _ESTI and the own vehicle speed _VA
(t) and on the basis to calculate the engine rotation speed command value _{N IN_ COM} from CVT shift map shown in FIG. 19. Then, the shift command value DRATIO (t) is _obtained from the following equation _based on the own vehicle speed _VA (t) and the engine speed command value _{NIN_COM} . DRATIO (t) = N _{IN_COM} · 2π · Rt / [6
0 · V _A (t) · Gf] where Gf is the final gear ratio.

(2) When coast switch 30 is turned on Coast switch 30 is turned on and vehicle speed command maximum value V
_{When the SMAX} is lowered, the shift command value DRATIO
The previous shift command value DRATIO (t-1) is held as (t). Therefore, even when the coast switch 30 is continuously turned on, the shift command value is not changed.
Since the previous value, that is, the value immediately before the coast switch 30 is turned on, is held until is turned off, no downshift is performed. Accordingly, when the set vehicle speed is returned by the accelerator switch 40 after the set vehicle speed is greatly reduced, the engine speed is rapidly increased in a state where the downshift is not performed, even if the throttle opening is controlled to open in order to accelerate. It is possible to prevent generation of noise given to the driver.

[0057] actual gear ratio calculator 550 of FIG. 10, an engine rotation sensor 80 detects the ignition signal of the engine the engine speed _{N E} (t), by the vehicle speed _{V A} (t),
The actual speed ratio RATIO (t) is calculated according to the following equation. _{RATIO (t) = N E (} t) / _{[V A (t) · Gf ·} 2π ·
Rt] The engine torque command value calculation unit 560 of FIG. 10 calculates the engine torque command value TE _COM (t) from the drive torque command value d _FC (t) and RATIO (t) according to the following equation. TE _COM (t) = d _FC (t) / [Gf · RATIO
(t)].

The target throttle opening calculating section 570 shown in FIG.
The engine torque command value _{TE CO M} (t) and on the basis of the engine speed _{N E} (t), the engine performance map shown in FIG. 20, the target throttle opening TVO
_COM is calculated and output to the throttle actuator 60.

The brake pressure command value calculator 630 shown in FIG.
Calculates the engine brake torque TE _COM ′ when the throttle is fully closed from the full engine performance map shown in FIG. 20 based on the engine speed _NE (t), and calculates the engine brake torque TE _COM ′ and the engine torque command value TE.
_{From COM} (t), the brake pressure command value REF is calculated by the following equation.
_{PB RK} (t) is calculated, and the brake actuator 50 is calculated.
Output to REF _PBRK (t) = (TE _COM -TE _COM ').
Gm · Gf / {4 · (2 · AB · RB · μB)} where Gm is the gear ratio of the automatic transmission, AB is the wheel cylinder force (cylinder pressure × area), RB is the effective radius of the disk rotor, and μB is the pad The coefficient of friction.

Next, the suspension process of the vehicle speed control will be described. The vehicle speed control interruption determination unit 620 in FIG. 10 receives the accelerator operation amount APO detected by the accelerator pedal sensor 90 and compares the accelerator operation amount APO with a predetermined value. This predetermined value is the accelerator operation amount APO ₁ corresponding to the target throttle opening TVO _COM input from the target throttle opening calculation unit 570, that is, the accelerator opening corresponding to the automatically controlled vehicle speed at that time. And
When the accelerator operation amount APO is larger than the predetermined value,
In other words, when the driver steps on the accelerator pedal,
If the throttle opening has been opened by the throttle actuator 60 at that time or more, a vehicle speed control interruption signal is output.

In response to the vehicle speed control interruption signal, the drive torque command value calculation section 530 and the target throttle opening calculation section 570 initialize the calculation up to that point, and the continuously variable transmission 70 is controlled by the transmission controller at a constant speed. Switching from the traveling shift map to the normal traveling shift map is performed.
That is, the constant-speed traveling by the automatic control is interrupted, and the normal traveling control corresponding to the driver's accelerator operation is performed.

The continuously variable transmission 70 has a normal traveling speed change map and a constant speed traveling speed change map. When the constant speed traveling control is interrupted, the vehicle speed control device instructs the transmission to transmit from the constant speed traveling speed change map to the normal traveling speed change map. The command for switching to the gear change map is output. Here, the shift map for normal traveling is, for example, a control map that is steep (has a good response) so that the downshift does not become slow during acceleration, and the shift map for constant-speed traveling is gentle so as to give a feeling of looseness. By using the control map, the driver does not feel uncomfortable when switching from constant-speed running to normal running.

The vehicle speed control interruption determining section 620 stops outputting the vehicle speed control interruption signal when the accelerator operation amount AP0 returns to less than the predetermined value, and sets the own vehicle speed V _A (t) to the vehicle speed designated maximum value. If it is larger than V _SMAX , a deceleration request is output to drive torque command value calculation section 530. Then, the drive torque command value calculation unit 530 stops outputting the vehicle speed control interruption signal from the vehicle speed control interruption determination unit 620,
When a deceleration request is input, the deceleration is controlled by the throttle opening calculated by the target throttle opening calculator 570 so that the calculated driving force command value d _FC (t) is realized by the throttle. When the braking force is not sufficient only by fully closing the throttle, the gear ratio command value calculation unit 540 sends the gear ratio command value DRATIO (shift down request, ) Is output to perform the downshift control of the continuously variable transmission 70 so as to compensate for the insufficient braking force.

The driving (braking in this case) force command value d
_{When FC} (t) is large and the braking force due to the downshift of the continuously variable transmission is at the upper limit, the braking force is supplemented by the normal brake on a flat road, but the braking torque is calculated from the driving torque command value calculation unit 530 on a downhill road. A brake control prohibition signal _BP is output to the pressure command value calculation unit 630, thereby prohibiting brake control on a downhill road. The reason for such control is as follows. That is, when the vehicle is decelerated on a downhill, it is necessary to apply the brake continuously when decelerating with the brake, and there is a possibility that a problem such as a brake fade may occur. Therefore, as described above, braking is performed without using a brake by controlling to obtain a necessary braking force only by deceleration by the throttle opening and the downshift control of the continuously variable transmission on a downhill road. I have.

According to the above-described method, even if the constant-speed cruise control is interrupted by the driver temporarily depressing the accelerator pedal to accelerate and then returned to the constant-speed cruise control, the shift of the transmission can be performed. Since the deceleration can provide a deceleration larger than the deceleration of only the throttle opening fully closed control, the convergence time to the target vehicle speed can be shortened. Also, by using a continuously variable transmission,
Shift shock does not occur even on a long downhill, it is larger than the deceleration of only the throttle opening fully closed control, and
Since the throttle and the gear ratio are controlled so as to realize the driving torque based on the vehicle speed command value change amount ΔV _COM (t), the vehicle can be smoothly decelerated while maintaining a predetermined deceleration. Incidentally, since a shock occurs at the time of downshifting in a normal step-variable transmission, conventionally, even when the deceleration control request is large as described above, only the throttle control is performed, and the downshift control of the transmission is not performed. However, if the continuously variable transmission is used, the downshift can be performed smoothly, so by performing the control as described above, it is possible to smoothly decelerate at a large deceleration greater than the deceleration of only the throttle opening fully closed control. Next, the vehicle speed control suspension process will be described. The driving wheel acceleration calculation unit 600 in FIG.
The vehicle speed V _A (t) is input, and the driving wheel acceleration α _OBS (t) is calculated by the following equation. α _OBS (t) = [K _OBS · s / (T _OBS · s ² +
s + K _OBS )] · V _A (t) where K _OBS is a constant and T _OBS is a time constant. The own vehicle speed V _A (t) is a value calculated from the rotation speed of the tire (drive wheel) as described above. Therefore, this value itself is a value corresponding to the rotation speed of the drive wheel. drive wheel acceleration alpha _OBS (t) is in the values obtained a variation in the vehicle speed from the driving wheel speed V _a (t) (drive wheel acceleration).

The vehicle speed control suspension determination unit 610 determines the driving wheel acceleration α obtained by the driving wheel acceleration calculating unit 600.
_OBS (t) is compared with a predetermined acceleration limit value α (this acceleration is a value corresponding to a change amount of the vehicle speed, for example, 0.2 G), and the drive wheel acceleration α _OBS (t) is set to the acceleration limit value α.
, A vehicle speed control stop signal is output. In response to the vehicle speed control stop signal, the drive torque command value calculation section 530
And the target throttle opening calculating section 570 initializes the calculation. Note that once the vehicle speed control is stopped, the vehicle speed control does not return until the set switch 20 is turned on again.

The apparatus shown in FIG. 10 is a vehicle speed command value change amount determining unit.
The vehicle speed command value change amount ΔV determined in 590_COMBased on
System that controls the vehicle speed with the vehicle speed command value
In a normal state, the vehicle speed command value change amount limit value [for example,
0.06G = 0.021 (km / h) / 10 (ms)]
No more change in vehicle speed occurs. Therefore, the driving wheel acceleration α
_OBS(t) corresponds to the above vehicle speed command value change amount limit value.
The predetermined acceleration limit value α (for example, 0.2
If G) is exceeded, the drive wheels will slip
It is likely that you did. Thus, the driving wheel acceleration α
_OBS(t) is compared with a predetermined acceleration limit value α
Can detect the occurrence of slip.
You. Therefore, TCS (traction control system)
A separate acceleration sensor is installed with a slip suppression device such as
To detect the difference in the number of revolutions between the drive wheel and the driven wheel.
Without a normal vehicle speed sensor (detects the rotational speed of the drive wheels
Of the driving wheel acceleration α_OBSAsk for
To judge the slip and the stop of the control.
be able to. The vehicle speed command value change amount ΔV_COMIs large
By improving the response to the target vehicle speed
it can. The driving wheel acceleration α_{O BS}(t) and predetermined value
Instead of judging that constant-speed cruise control should be stopped based on the comparison of
The vehicle speed command value change calculated by the command value change amount determination unit 590
Amount ΔV_COMAnd drive wheel acceleration α_OBSdifference from (t)
Stop the control when it exceeds the specified value.
Is also good.

The vehicle speed command value determining unit 510 shown in FIG. 10 determines whether or not the preceding vehicle has been detected based on the input flag F. If it is determined that the preceding vehicle has not been detected, it is determined by itself. The calculated vehicle speed command value V _COM (t) is
It is determined whether the speed is higher than the input vehicle speed _VA (t) and changes in the deceleration direction ( _VSMAX < _VA ). Then, the vehicle speed command value V _{COM is set} to the own vehicle speed V _A (t) or a predetermined speed V _COM (t) or lower (for example, a value obtained by subtracting 5 km / h from the own vehicle speed), as shown in FIG. In drive torque command value calculation section 530,
C ₂ (s) · V _A (t) −C ₁ (s) · d _FC (t) = d _V
To make the output of (t) zero, C ₂ (s) and C
The initial value of the integrator of ₁ (s) is assumed to be the own vehicle speed _VA (t). As a result, both the output of C ₁ (s) and the output of C ₂ (s) are _VA (t).
As a result, the disturbance estimation value d _V (t) becomes zero. Further, as a timing for performing the above control, V
_COM (t) rate of change in a ΔV _COM (t) is a predetermined value
(0.06G) on the deceleration side. Thereby, unnecessary initialization (initialization of _VA (t) → _VCOM (t) and initialization of the integrator) is reduced, so that deceleration shock is reduced. As described above, when the vehicle speed command value (control command value every moment until reaching the target vehicle speed) is larger than the actual vehicle speed and the temporal change of the vehicle speed command value changes in the deceleration direction, the vehicle speed command value Can be quickly converged to the target vehicle speed by changing the vehicle speed to the actual vehicle speed or a predetermined vehicle speed lower than the actual vehicle speed. The driving torque command value calculating unit 5 uses the actual vehicle speed set as described above or a vehicle speed lower than the actual vehicle speed.
By initializing 30, the continuity of control can be maintained.

In a vehicle speed control device that controls the actual inter-vehicle distance to be equal to the target inter-vehicle distance so that the vehicle travels while maintaining the target inter-vehicle distance with the preceding vehicle set by the driver, the above vehicle speed command value is The target inter-vehicle distance is set to be maintained, but if it is determined that the preceding vehicle is detected based on the input flag F, the actual inter-vehicle distance is equal to or less than a predetermined value, and the vehicle speed command value change amount ΔV _COM ( t) is greater than the predetermined value (0.06G) on the deceleration side, the vehicle speed command value V
The change of _COM (t) [ _VA (t) → V _COM (t)] and the initialization of the drive torque command value calculation section 530 (specifically, the integrator therein) are performed. With this configuration,
Since the vehicle can be quickly converged to the target inter-vehicle distance, there is no possibility that the vehicle approaches the preceding vehicle too much, and the continuity of control can be maintained. This also, unnecessary initialization [V _A (t) → initialization and integrator initialization of the ΔV _{CO M} (t)) is so decreased, the deceleration shock is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an inter-vehicle distance control device according to the present invention.

FIG. 2 is a block diagram showing a configuration of an inter-vehicle distance command value calculation unit 110.

FIG. 3 is a characteristic diagram showing a step response of a transfer function of a set inter-vehicle time phase advance compensator 111;

FIG. 4 is a block diagram showing a configuration of a vehicle speed control system feedback characteristic determining unit 300.

5A and 5B are characteristic diagrams for determining each coefficient in a vehicle speed control system feedback characteristic determination unit 300, wherein FIG. 5A is a map for determining an inter-vehicle control feedback system damping coefficient _{ｎ nDB} , and FIG. The map for determining the natural frequency ω _nDB of the feedback system.

FIG. 6 is a map for _{obtaining a} correction coefficient _CD1 .

FIG. 7 is a map for obtaining a road surface gradient amount φ _A (t).

FIG. 8 is a map for _{obtaining a} correction coefficient _CD3 .

FIG. 9 is a map for _{obtaining a} correction coefficient _CD4 .

FIG. 10 is a block diagram showing the overall configuration of a vehicle speed control device.

FIG. 11 is a block diagram showing a configuration of a lateral G vehicle speed correction amount calculation unit 580.

FIG. 12 is a characteristic diagram showing a relationship between a vehicle speed _VA and a cutoff frequency fc of a low-pass filter.

FIG. 13 is a characteristic diagram showing a relationship between a correction coefficient for calculating a vehicle speed correction amount V _SUB (t) and a value _{G G} (t) of a lateral G.

[14] characteristic diagram showing the relationship between the natural frequency omega _NSTR and vehicle speed _{V A.}

FIG. 15 shows a vehicle speed V _A (t) and a vehicle speed command maximum value V;
The absolute value of the deviation from _SMAX and the vehicle speed command value change amount ΔV
FIG. 4 is a characteristic diagram showing a relationship with _COM (t).

FIG. 16 is a block diagram showing a configuration of a drive torque command value calculation unit 530.

FIG. 17 is a diagram showing an example of an engine non-linear steady-state characteristic map.

FIG. 18 is a diagram showing an example of a throttle opening degree estimation map.

FIG. 19 is a diagram showing an example of a CVT shift map.

FIG. 20 is a diagram showing an example of an entire engine performance map.

FIG. 21 is a block diagram showing another example of the configuration of the drive torque command value calculation unit 530.

[Explanation of symbols]

Reference Signs List 10 vehicle speed sensor 15 inter-vehicle distance sensor 20 set switch 30 coast switch 40 accelerator switch 50 brake actuator 60 throttle actuator 70 continuously variable transmission 80 engine rotation sensor 90 accelerator pedal sensor 100 steering angle Sensor 105: Inter-vehicle distance control unit 110: Inter-vehicle distance command value calculation unit 111: Set inter-vehicle time phase advance compensation unit 112: Inter-vehicle distance command value determination unit 120: Target inter-vehicle distance calculation unit 130: Pre-compensation vehicle speed command value calculation unit 140 ... inter-vehicle control vehicle speed command value calculation section 150 ... inter-vehicle time setting section 300 ... inter-vehicle control feedback characteristic determination section 310 ... feedback system attenuation coefficient determination section 311 ... feedback system attenuation coefficient correction section 320 ... feedback system natural frequency determination section 330 ... feed Bag System natural frequency first correction unit 331: Feedback system natural frequency second correction unit 340 ... Feedback constant determination unit 500 ... Vehicle speed control unit 510 ... Vehicle speed command value determination unit 520 ... Vehicle speed command maximum value setting unit 530 ... Drive torque command Value calculation unit 540: Shift command value calculation unit 550: Actual gear ratio calculation unit 560: Engine torque command value calculation unit 570 ... Target throttle opening calculation unit 580 ... Lateral G vehicle speed correction amount calculation unit 581 ... Steering angle signal LPF unit 582 ··· Lateral G calculation unit 583 ··· Vehicle speed correction amount calculation map 590 ··· Vehicle speed command value change amount determination unit 600 ··· Drive wheel acceleration calculation unit 610 ··· Vehicle speed control stop determination unit 620 ··· Vehicle speed control interruption determination unit 630 ··· Brake pressure command value calculation unit L _A (t) ... inter-vehicle distance ΔV (t) ...
The relative velocity V ^* (t) ... inter-vehicle control vehicle speed command value d _T (t) ...
Inter-vehicle time L ^* (t): inter-vehicle distance command value ΔV _T (t)
... target relative speed L _T (t) ... target inter-vehicle distance F ... preceding vehicle flag V _C (t) ... correction command vehicle speed f _L, f V _... feedback constant V _A (t) ... vehicle speed V _SMAX
... Vehicle speed command maximum value θ (t) ... Steering angle V
_SUB (t): vehicle speed correction amount θ _LPF (t): steering angle LPF value V
_COM (t): vehicle speed command value ΔV _COM (t): vehicle speed command value change amount d
_FC (t) ... command drive torque d _V (t) ... estimated disturbance value d _V (t) '... command drive torque correction quantity d _FA (t) ... actual driving torque C _F (s)
... predistorter C _R (s) ... norm model calculating section d _FC1 (t) ... reference driving torque command value _{C 1 (s), C 2} (s), C 3 (s) ... compensator C ₃ (s ) '... feedback compensator s ... differential operator fc ... cutoff frequency of LPF Y _G (t) ... value of lateral G ψ ... yaw rate ω _nSTR ... natural frequency of vehicle response to steering angle α _OBS ... drive wheel acceleration TVO _ESTI : Estimated throttle opening TVO _COM : Target throttle opening APO:
Accelerator operation amount N _{IN_COM} ... engine speed command value DRA
TIO (t): shift command value TE _COM (t): engine torque command value TE _COM ': engine brake torque REF _PBRK (t): brake pressure command value _BP : brake control inhibit signal

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B60R 21/00 624 B60R 21/00 624D 624G 624B F02D 29/02 301 F02D 29/02 301D 41/04 330 41/04 330G 41/14 330 41/14 330Z G08G 1/16 G08G 1/16 E (72) Inventor Takeshi Ishizu 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Hideki Kato Fujiki, Yokohama, Kanagawa 2F, Takaracho, Kanagawa-ku Nissan Motor Co., Ltd. F-term (reference) DA01 DA06 DB05 DB16 DB18 EA09 EB03 EB04 EC02 EC04 FA02 FA05 FA07 FA11 FA12 3G301 JA03 JA11 KB02 KB07 LA03 LC03 LC06 NA03 NA04 NA05 NA08 NC02 ND02 ND05 PE01Z PF01A PF01Z PF03Z PF15Z 5H180 AA01 CC03 CC14LL

Claims (3)

[Claims] An inter-vehicle distance control device that performs feedback control so as to maintain the inter-vehicle distance between a preceding vehicle and a host vehicle at a target inter-vehicle distance, comprising: means for detecting a value corresponding to an inclination angle of an uphill road; An inter-vehicle distance control device, wherein the responsiveness of feedback of inter-vehicle distance control determined according to a relative speed with respect to a host vehicle is corrected so as to be increased according to a value corresponding to the inclination angle of the uphill road. 2. An inter-vehicle distance control device that performs feedback control so as to maintain the inter-vehicle distance between a preceding vehicle and a host vehicle at a target inter-vehicle distance, comprising: means for detecting a value corresponding to an inclination angle of an uphill road; An inter-vehicle distance control device characterized in that the value of the distance is set to be large according to the value corresponding to the inclination angle of the uphill road. 3. A target vehicle speed is calculated so as to coincide with a target inter-vehicle distance, and a deviation amount from a motion characteristic of a controlled object is estimated.
An inter-vehicle distance control device that corrects the target vehicle speed with the estimated deviation amount to obtain a new target vehicle speed and controls the vehicle speed accordingly, wherein the value corresponding to the inclination angle of the uphill road is the estimated deviation amount. The inter-vehicle distance control device according to claim 1 or 2, wherein the determination is made based on: