JP2001328457A - Vehicle speed control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle speed control device having excellent responsiveness in vehicle-to-vehicle distance control and keeping a driver from feeling a sense of incongruity in vehicle speed control in the case of using a vacuum type actuator. SOLUTION: This vehicle speed control device uses a vacuum type actuator and quickens the response characteristics of a vehicle-to-vehicle distance control part and a vehicle speed control part in the case of a preceding vehicle going away at the relative speed variation within a vehicle speed variation limit value in comparison with the case of the preceding vehicle going away at the relative speed variation of the vehicle speed variation limit value or more and the case of not detecting the preceding vehicle. Even in the presence of the preceding vehicle, if the preceding vehicle is going away at the relative speed variation within the vehicle speed variation limit value, a control delay can be prevented by controlling the vehicle-to-vehicle distance with a quick response characteristic. In the case of the preceding vehicle going away at the relative speed variation of the vehicle speed variation limit value or more, vehicle speed control within the vehicle speed variation limit value is difficult at this point, so that the response characteristic is slowed to become close to the response characteristic of the vacuum type actuator, thus performing vehicle speed control without a jerky feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a prior art of a vehicle speed control device having an inter-vehicle distance control function, Japanese Patent Application No. 11-166828 discloses a prior art.
There is a thing described in the issue (undisclosed). In such prior art, the vehicle speed is controlled to be a smaller one of a target vehicle speed for maintaining a predetermined inter-vehicle distance and a set vehicle speed set by a driver. The vehicle speed is controlled so as to maintain the vehicle speed set by the driver (the target vehicle speed for constant speed traveling). When the driver operates a coast switch for lowering the set vehicle speed or an accelerator switch for increasing the set vehicle speed, the set vehicle speed changes by a predetermined amount, and the vehicle speed is set to the predetermined vehicle speed with the set vehicle speed after the change as the target vehicle speed. It is configured to control with a change amount (acceleration or deceleration).

[0003]

However, when a negative pressure type actuator or a step motor type actuator is used as a throttle actuator for controlling the vehicle speed from the viewpoint of cost and mountability, there are the following problems. In other words, in a system in which the vehicle speed control unit controls the vehicle speed using the output of the following distance control unit, it is necessary to match the response characteristics of the vehicle speed control unit and the following distance control unit.
If this response characteristic is matched with a low response characteristic of a negative pressure actuator or the like, the inter-vehicle distance control in which the inter-vehicle distance with the preceding vehicle follows the target inter-vehicle distance becomes slow. Conversely, if the response characteristic is matched to a response characteristic higher than the response characteristic of a negative pressure actuator or the like, a jerky feeling is generated by the vehicle speed control, giving the driver an uncomfortable feeling.

The present invention has been made to solve the problems of the prior art as described above. When an actuator having a low response characteristic such as a negative pressure type actuator is employed, the responsiveness of the following distance control is good, and It is another object of the present invention to provide a vehicle speed control device that does not give a driver an uncomfortable feeling in vehicle speed control.

[0005]

In order to achieve the above object, the present invention is configured as described in the appended claims. That is, in the first aspect, the response characteristics of the inter-vehicle distance control unit and the vehicle speed control unit are made faster when a preceding vehicle is present than when the preceding vehicle is not present.

According to a second aspect of the present invention, when the preceding vehicle leaves at a relative speed change amount within the vehicle speed change amount limit value, the preceding vehicle leaves at a relative speed change amount equal to or greater than the vehicle speed change amount limit value. The response characteristics of the inter-vehicle distance control unit and the vehicle speed control unit are configured to be faster than in the case where the preceding vehicle is not detected.

In the present invention, when the own vehicle runs within the set vehicle speed and the preceding vehicle leaves, when the preceding vehicle is not detected, when the own vehicle runs at the set vehicle speed, and The response characteristics of the inter-vehicle distance control unit and the vehicle speed control unit are configured to be faster than when the preceding vehicle leaves.

According to a fourth aspect of the present invention, when the preceding vehicle is traveling within the constant-speed traveling target vehicle speed, the preceding vehicle is traveling at or above the constant-speed traveling target vehicle speed, or the preceding vehicle is detected. The response characteristics in the inter-vehicle distance control unit and the vehicle speed control unit are configured to be faster than in the case where the control is not performed.

Further, a case in which a negative pressure type actuator is used as an example of the throttle actuator will be described.

[0010]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the response characteristic is fast when there is a preceding vehicle, so that a delay in inter-vehicle distance control can be prevented, and the response characteristic is slow when there is no preceding vehicle. Is small, the jerky feeling can be reduced, and it is possible to prevent the driver from feeling uncomfortable.

According to a second aspect of the present invention, even when there is a preceding vehicle, if the preceding vehicle leaves at a relative speed change amount within the vehicle speed change amount limit value, the vehicle speed within the vehicle speed change amount limit value is set. Since the control is performed, the control delay can be prevented by performing the following distance control with a fast response characteristic. Also, when the preceding vehicle leaves at a relative speed change amount equal to or greater than the vehicle speed change amount limit value, it is difficult to control the vehicle speed within the vehicle speed change amount limit value. It is possible to perform a vehicle speed control without a jerky feeling by approaching a low response characteristic of an actuator or the like. In addition, when there is no preceding vehicle, the response characteristic is slow, so that the unmatching with the low response characteristic of the negative pressure actuator or the like is small, the jerky feeling can be reduced, and the driver can be prevented from feeling uncomfortable.

According to a third aspect of the present invention, even when a preceding vehicle is present, if the own vehicle runs within the target speed for constant-speed driving and the preceding vehicle leaves, the change in vehicle speed is not more than the limit value. Since it is highly possible that the vehicle speed control is performed, the control delay can be prevented by performing the inter-vehicle distance control with a fast response characteristic. In addition, when the preceding vehicle leaves at a relative speed change amount equal to or larger than the vehicle speed change amount limit value, it is considered that it is no longer possible to control the vehicle speed within the vehicle speed change amount limit value. In addition, the vehicle speed control without the jerky feeling can be performed by approaching the low response characteristics of the negative pressure type actuator or the like. In addition, when there is no preceding vehicle, the response characteristic is slow, so that the unmatching with the low response characteristic of the negative pressure actuator or the like is small, the jerky feeling can be reduced, and the driver can be prevented from feeling uncomfortable.

According to a fourth aspect of the present invention, even when there is a preceding vehicle, if the preceding vehicle is running within the constant speed target vehicle speed, the vehicle speed is controlled within the vehicle speed change amount limit value. Since there is a high possibility that the control is performed, the control delay can be prevented by performing the inter-vehicle distance control with a fast response characteristic. Also, if the preceding vehicle is running at a speed equal to or higher than the constant speed target vehicle speed,
Since it is considered that the vehicle speed control within the vehicle speed change amount limit value is no longer difficult, by lowering the response characteristics, the vehicle speed control can be performed without the jerky feeling by approaching the low response characteristics of a negative pressure actuator or the like. In addition, when there is no preceding vehicle, the response characteristic is slow, so that the unmatching with the low response characteristic of the negative pressure actuator or the like is small, the jerky feeling can be reduced, and the driver can be prevented from feeling uncomfortable.

[0014]

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) V _A (t) of the vehicle from the rotational speed of the tire. 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.

[0021]

(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).

[0022]

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

The inter-vehicle distance control vehicle speed command value calculation unit 140
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  Hereinafter, the gist of the present invention will be described. In the present invention
Is negative as the throttle actuator of FIG.
Use a pressure actuator. In addition, the negative pressure type actuator
The eta operates by using negative pressure as a power source.
Negative pressure may be generated by driving a vacuum motor.
Alternatively, negative pressure in the intake pipe can be used. Negative pressure activator
The estimator is generally inexpensive and easy to mount on vehicles,
Responsiveness is slow. Target inter-vehicle distance calculation unit of inter-vehicle control unit 100
120 and drive torque command value calculation of vehicle speed control section 500
Dead time L in section 530_V(t) is the negative pressure slot.
Torque actuator dead time and engine has
The value is set to the sum of the dead time.

Vehicle speed control feedback characteristic determining unit 300
Receives the inter-vehicle distance L _A (t) and the relative velocity Δ _V (t) and the flag F from the inter-vehicle distance sensor 15 detects the presence or absence of the preceding vehicle from the flag F, performs case analysis following such. (A1) When the preceding vehicle is detected and the preceding vehicle is separated by a predetermined value or more (a2) When the preceding vehicle is not detected (b1) The preceding vehicle is detected and the preceding vehicle is smaller than the predetermined value (B2) When the preceding vehicle is detected and approaching or running at the same speed, the relative speed change amount is the relative speed _ΔV (t) Is determined from the sign of the relative speed _ΔV (t) based on the time change of the vehicle and whether the preceding vehicle approaches or leaves. And case a
(A1, a2), when compared to the b (b1 and b2), it is set to a large value the dead time _{L V} (t) of the vehicle speed control section 500. Then, these dead times L _V (t) are transmitted to target inter-vehicle distance calculation section 120 of inter-vehicle distance control section 105 and drive torque command value calculation section 530 of vehicle speed control section 500. As a result, the response characteristic is slowed down, so that the driver does not feel uncomfortable in either the constant speed traveling control or the inter-vehicle distance control.

The following case (c) may be used instead of the above case (a), and the following case (d) may be used instead of the case (b). (C1) The preceding vehicle is detected, and the own vehicle is in the vehicle speed command maximum value V
_{When the} vehicle is traveling in _SMAX ( _VSMAX input is not shown) and the preceding vehicle is leaving (the relative speed is determined to be positive) (c2) When the preceding vehicle is not detected (d1) The preceding vehicle is detected And the vehicle is V _SMAX (V
_(SMAX input is not shown) When traveling at a lower speed and moving away (d2) When the preceding vehicle is detected and approaching or when traveling at the same speed Further, the above case The following case (e) may be used instead of (a) and (c), and the following case (f) may be used instead of cases (b) and (d). (E1) When the preceding vehicle is detected and the preceding vehicle is running at V _SMAX or higher (the speed of the preceding vehicle is calculated from the relative speed and the own vehicle speed). (E2) When the preceding vehicle is not detected (f1) ) When the preceding vehicle is detected and the preceding vehicle travels within _VSMAX and leaves (f2) The preceding vehicle is detected and when the preceding vehicle approaches or runs at the same speed. Thus, in cases (a), (c) and (e), case (b)
(D) Since the dead time L _V (t) is set to a large value as compared with (f), the response characteristics are slow, and can be matched with the response characteristics of the negative pressure type actuator.

In the example described above, the dead time L _V (t)
The was to be changed, may change the constant T _V when the vehicle speed control section 500 in place of the dead time L _V (t),
Or may instead both _{L V} and _{T V,} if (a)
In (c) and (e), compared to cases (b), (d) and (f),
Set to a large value.

In the above example, the inter-vehicle distance control unit 10
5 target inter-vehicle distance calculation unit 120 and vehicle speed control unit 500
Dead time L _V in the drive torque command value calculating portion 530 of the
(t) is set to a value obtained by adding the dead time of the negative pressure type throttle actuator and the dead time of the engine, but instead of this, the target inter-vehicle distance calculation unit 120 of the inter-vehicle distance control unit 105 is set. And dead time L in drive torque command value calculation section 530 of vehicle speed control section 500
_V (t) may be the same as the dead time of the negative pressure type throttle actuator. In this case, cases (a) and (c)
Similar effects can be obtained by reducing cases (b), (d) and (f) as compared to (e). It should be noted that whether (a) or (b) is changed depending on whether the response characteristic of the control is adjusted to the actuator or larger than the actuator, the relative magnitude relationship between (a) and (b) is changed. Absent.

As described above, even when there is a preceding vehicle, if the preceding vehicle leaves at a relative speed change amount within the vehicle speed change amount limit value, the vehicle speed control within the vehicle speed change amount limit value is performed. Therefore, control delay can be prevented by controlling the following distance with a fast response characteristic. In addition, when the preceding vehicle leaves at a relative speed change amount equal to or greater than the vehicle speed change amount limit value, it is difficult to control the vehicle speed within the vehicle speed change amount limit value. The vehicle speed control without the jerky feeling can be performed by approaching the response characteristics of the actuator. In addition, since the response characteristic is slow when there is no preceding vehicle, the unmatching with the response characteristic of the negative pressure type actuator is small, the jerky feeling can be reduced, and it is possible to prevent the driver from feeling uncomfortable. (C)
The same effects as described above can be obtained even with the configurations shown in (e), (d), and (f). The above is the description of the main part of the present invention.

Further, vehicle control feedback characteristic determining unit 300, the inter-vehicle distance _{L A} (t), type a relative speed [Delta] V (t) and the set inter-vehicle time _{d T} (t), the feedback constants _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 shows an inter-vehicle control feedback characteristic determining unit 30.
0 shows a block diagram. The inter-vehicle control feedback characteristic determining unit 300 includes a feedback system damping coefficient determining unit 310, a feedback system damping coefficient correcting unit 311, and a feedback system natural frequency determining unit 32 of the inter-vehicle distance control unit 105.
0, 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.

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 determination 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. Feedback system damping coefficient correction unit
311 is a drive torque command value calculation unit of the vehicle speed control unit 500
The disturbance estimation value d calculated in 530_VEnter (t)
The feedback system damping coefficient determination unit 310
_nDBAnd the disturbance estimation value d_VFrom (t) the amount of road gradient
φ_AEstimate (t). Specifically, as shown in FIG.
And the disturbance estimate d_VIf (t) is negative,
If it is positive, it is regarded as a downhill road and the road surface gradient amount φ_A(t)
Ask for. Then, based on FIG._D3Seeking
Therefore, the damping coefficient of the headway control feedback system ζ_nDBComplement
Correct the damping coefficient ζ_nDBCDetermine the value of. Sand
And damping coefficient ζ_nDBCIs represented by the following equation. 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.

[0036] 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. 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, FIG.
The configuration and operation of each block at 0 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 (s) /
1 (s) × 5 (km / h)].
As described above, the vehicle speed finger is set by the set switch 20.
Command maximum value V_{S MAX}Is set after the acceleration
Each time the switch 40 is pressed once, the vehicle speed command maximum value setting unit
520 is the vehicle speed command maximum value V_SMAX5km / h
Set to a high value. That is, when pressed n times, n × 5 km /
h [If the button is held down, the pressing time is assumed to be t.
For example, a value higher by t (s) / 1 (s) × 5 (km / h)]
Is set to

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 accelerated 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.

To explain this point in detail, 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 determining section 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 is calculated from the actual vehicle speed V _A (t) when it is determined that the curve has ended.
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.

[0051] Incidentally, if 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 determination 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.

[0057] 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 method, a vehicle model that receives the driving torque command value d _FC (t) and outputs the own vehicle speed _VA (t) can be expressed 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).

In addition, ignoring the dead time of the control 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 determined 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 is used, 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 is small
It becomes. Therefore, the drive torque command value d_FC(t) is the reference drive torque 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 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.

[0066] 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, a description will be given of the suspension processing of the vehicle speed control. 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 controls the constant speed by the transmission controller. 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 shift map for normal running and a shift map for constant speed running. When the constant speed running control is interrupted, the vehicle speed control device sends the transmission to the transmission. 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.

Further, the vehicle speed control interruption determination section 620 stops outputting the vehicle speed control interruption signal when the accelerator operation amount AP0 returns below the predetermined value, and sets the own vehicle speed V _A (t) to the vehicle speed designated maximum value. If it is larger than _VSMAX , 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 (in this case, braking) 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 when 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 is also performed. By the down, a deceleration larger than the deceleration of only the throttle opening full-close control can be obtained, so that 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 that by performing the above control, it is possible to smoothly decelerate at a large deceleration greater than or equal to the deceleration of only the throttle opening fully closed control.

Next, the stop processing of the vehicle speed control will be described. Driven wheel acceleration calculating unit 600 of FIG. 10, vehicle speed _{V A}
(t), and drive wheel acceleration α
Calculate _OBS (t). 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 drive wheel acceleration α obtained by the drive wheel acceleration calculation 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 section 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 larger 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.

[Description of Signs] 10 ... Vehicle speed sensor 15 ... Vehicle distance sensor 20 ... Set switch 30 ... Coast switch 40 ... Accelerate 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: front compensation vehicle speed Command value calculating unit 140: inter-vehicle control vehicle speed command value calculating unit 150: inter-vehicle time setting unit 300: inter-vehicle control feedback characteristic determining unit 310: feedback system damping coefficient determining unit 311: feedback system damping coefficient correcting unit 320: feedback system natural frequency Decision unit 330 Feedback 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 ... Horizontal G vehicle speed correction amount calculation unit 581 ... Steering angle signal LPF unit Reference numeral 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 suspension determination unit 620: vehicle speed control suspension determination unit 630: brake pressure command value calculation part L _A (t) ... the 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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 29/02 F02D 29/02 D 41/14 320 41/14 320D G08G 1/16 G08G 1/16 EF Terms (reference) 3D044 AA01 AA04 AA45 AC05 AC16 AC19 AC26 AC31 AC59 AD04 AD17 AE01 AE04 AE19 AE22 3G065 CA20 DA02 EA05 EA13 FA05 FA08 FA11 GA00 GA10 GA11 GA28 GA41 GA46 KA29 KA36 3G093 AA06 DB03 DB03 DA03 CB06 DB16 DB21 EA09 EB03 EC04 FA05 FA10 FA11 FB05 3G301 JA03 KA16 KB02 KB07 KB10 LA03 LC07 NA08 NC04 ND05 NE17 PA11Z PE01Z PF01A PF01Z PF02Z PF03Z PF06Z PF15Z 5H180 AA01 BB15 CC03 CC14 LL01 LL04LL04

Claims (5)

[Claims] When there is a preceding vehicle, an inter-vehicle distance control unit calculates an inter-vehicle distance control target vehicle speed for maintaining an inter-vehicle distance set by a driver, and calculates a target inter-vehicle distance control target vehicle speed. The vehicle speed is controlled by the vehicle speed control unit based on the vehicle speed, and when there is no preceding vehicle, the vehicle speed is controlled so as to maintain the target vehicle speed for constant speed traveling set by the driver instead of the target vehicle speed for inter-vehicle distance control. In the vehicle speed control device, when the preceding vehicle exists,
A vehicle speed control device configured to increase the response characteristics of the inter-vehicle distance control unit and the vehicle speed control unit. 2. When a preceding vehicle exists, a target vehicle speed for maintaining a predetermined inter-vehicle distance between the preceding vehicle and the host vehicle is set, and the target vehicle speed and a constant speed traveling set by the driver are set. The vehicle speed is controlled so as to be a smaller vehicle speed than the target vehicle speed, and when there is no preceding vehicle, the vehicle speed is controlled so as to maintain the constant speed target vehicle speed set by the driver, and When calculating the instantaneous vehicle speed command value so as to eliminate the deviation between the target vehicle speed and the actual vehicle speed, in a vehicle speed control device that limits the amount of change in the vehicle speed instruction value to a predetermined vehicle speed change amount limit value or less, When the vehicle moves away with a relative speed change amount within the vehicle speed change amount limit value, the headway distance control unit is more advanced than when the preceding vehicle leaves with a relative speed change amount equal to or greater than the vehicle speed change amount limit value and when the preceding vehicle is not detected. And the response characteristics of the vehicle speed control unit Vehicle speed control device. 3. When there is a preceding vehicle, a target vehicle speed for maintaining a predetermined inter-vehicle distance between the preceding vehicle and the host vehicle is set, and the target vehicle speed and a constant speed traveling set by the driver are set. The vehicle speed is controlled so as to be a smaller vehicle speed than the target vehicle speed, and when there is no preceding vehicle, the vehicle speed is controlled so as to maintain the constant speed target vehicle speed set by the driver, and When calculating the instantaneous vehicle speed command value so as to eliminate the deviation between the target vehicle speed and the actual vehicle speed, in a vehicle speed control device that limits the amount of change in the vehicle speed instruction value to a predetermined vehicle speed change amount limit value or less, If the vehicle is traveling within the target vehicle speed for constant speed traveling and the preceding vehicle is leaving, the preceding vehicle is not detected and the own vehicle is traveling at the target vehicle speed for constant traveling and the preceding vehicle is leaving Response characteristics in the following distance control unit and the vehicle speed control unit A vehicle speed control device configured to speed up. 4. When there is a preceding vehicle, a target vehicle speed for maintaining a predetermined inter-vehicle distance between the preceding vehicle and the host vehicle is set, and the target vehicle speed and a constant speed traveling set by the driver are set. The vehicle speed is controlled so as to be a smaller vehicle speed than the target vehicle speed, and when there is no preceding vehicle, the vehicle speed is controlled so as to maintain the constant speed target vehicle speed set by the driver, and When calculating the instantaneous vehicle speed command value so as to eliminate the deviation between the target vehicle speed and the actual vehicle speed, in a vehicle speed control device that limits the amount of change in the vehicle speed instruction value to a predetermined vehicle speed change amount limit value or less, When the vehicle is traveling within the target vehicle speed for constant speed traveling, the inter-vehicle distance control unit and the vehicle speed control are higher than when the preceding vehicle is traveling at or above the target vehicle speed for constant speed traveling or when the preceding vehicle is not detected. Speed control configured to speed up the response characteristics in the vehicle apparatus. 5. A negative pressure type actuator using a negative pressure as a power source is used as a throttle actuator for adjusting a throttle opening degree.
The vehicle speed control device according to any one of the above.