JPH11334553A - Run controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a run controller for a vehicle capable of maintaining high safety without suddenly decelerating an own vehicle when another vehicle interrupts between the own vehicle and a preceding vehicle. SOLUTION: When another interrupting vehicle interrupts between an own vehicle and a preceding vehicle during follow-up run control, an inter-vehicle distance L between the own vehicle and another interrupting vehicle is suddenly short but, in such a case, a target inter-vehicle distance Lf is reduced in response to the short inter-vehicle distance L (Lf.L/La), whereby the target deceleration of the own vehicle is made temporarily small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for a vehicle, and more particularly, to a deceleration control technique in traveling control.

[0002]

2. Related Background Art In recent years, in order to reduce the driving operation of an automobile, a travel control device having an inter-vehicle distance control device for pursuing a preceding vehicle has been developed and put into practical use.

[0003] A traveling control device provided with this inter-vehicle distance control device detects an inter-vehicle distance between a host vehicle and a preceding vehicle based on information from a forward recognition device such as a camera or a laser radar. The engine output and the braking force are adjusted so that the distance becomes a preset target inter-vehicle distance, thereby accelerating and decelerating the vehicle and tracking the preceding vehicle.

Normally, in such a traveling control device, a target deceleration is calculated based on a relative speed between the own vehicle speed and a preceding vehicle speed. When the vehicle is decelerated, the target deceleration is calculated based on the target deceleration. The braking force is adjusted to control the vehicle deceleration.

[0005] By the way, during the tracking travel control, it is sufficient that the preceding vehicle is always the same vehicle, but the preceding vehicle is often replaced by interruption of another vehicle.

As described above, when the other vehicle enters the range of the original target inter-vehicle distance, the inter-vehicle distance decreases discontinuously and sharply, and accordingly, the own vehicle is suddenly braked and the vehicle is stopped. The occupant may feel uncomfortable, such as a deceleration shock.

Therefore, when another vehicle is interrupted in this way, a pseudo inter-vehicle distance is assumed to be such that the inter-vehicle distance gradually changes without discontinuity, and the vehicle speed is determined based on the pseudo inter-vehicle distance. An apparatus configured to control the vehicle speed and avoid sudden deceleration of the vehicle is disclosed in Japanese Patent Application Laid-Open No. 8-127268.

[0008]

However, the apparatus disclosed in the above publication performs control using a concept of a pseudo inter-vehicle distance that does not actually exist, and thus has a problem in running safety of a vehicle.

That is, in the control of the device, the own vehicle is far longer than the shortened inter-vehicle distance for a while, although the inter-vehicle distance is actually sharply shortened by interruption of another vehicle. The tracking control is performed with a target of a pseudo inter-vehicle distance that is a distance, that is, a position substantially ahead of other vehicles, and the vehicle is actually traveling without looking at the other vehicle that has interrupted the vehicle, which is preferable in terms of safety. It is not.

According to this device, for example, when another vehicle decelerates after interruption, the own vehicle inadvertently approaches the other vehicle without following the deceleration of the other vehicle. There is a fear.

The present invention has been made based on the above-described circumstances, and an object of the present invention is to prevent the vehicle from suddenly decelerating when another vehicle interrupts between the vehicle and the preceding vehicle. Another object of the present invention is to provide a vehicle traveling control device capable of maintaining high safety.

[0012]

To achieve the above object, according to the first aspect of the present invention, the vehicle speed of the own vehicle is controlled so that the inter-vehicle distance between the own vehicle and the preceding vehicle becomes the target inter-vehicle distance. In a travel control device for a vehicle that performs travel control, a target deceleration calculation unit calculates a target deceleration of the own vehicle based on the own vehicle speed, a preceding vehicle speed, an inter-vehicle distance, and a target inter-vehicle distance. Is controlled based on the calculated target deceleration.However, when the inter-vehicle distance suddenly decreases and becomes shorter than the target inter-vehicle distance, the target inter-vehicle distance is reduced by the target inter-vehicle distance reducing means. It is reduced according to the distance between vehicles.

That is, if another vehicle interrupts between the host vehicle and the preceding vehicle during the tracking drive control, the inter-vehicle distance between the host vehicle and the interrupted other vehicle suddenly becomes short. However, in such a case, the target inter-vehicle distance is reduced according to the shortened inter-vehicle distance, and the target deceleration is reduced.

Therefore, even if another vehicle interrupts between the host vehicle and the preceding vehicle, the host vehicle can be decelerated slowly without sudden braking, and the occupant feels a deceleration shock. A smooth tracking drive control without any trouble is realized.

[0015] In addition, although the vehicle is reduced in this way, by always having the target inter-vehicle distance, it is possible to preferably prevent the own vehicle from inadvertently approaching the other vehicle that has been interrupted. Good safety is ensured.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a schematic configuration diagram of a traveling control device according to the present invention mounted on a vehicle 1. Hereinafter, the traveling control device according to the present invention will be described with reference to FIG. The configuration will be described.

At the front of the vehicle 1, a laser beam is emitted toward the front, and by scanning this laser beam, an object located in front of the vehicle 1 can be recognized, and the distance to the object can be measured. A simple scanning laser radar 2 is provided. In addition, the vehicle 1
A CCD camera 4 for capturing an image in front of is mounted. The CCD camera 4 is also capable of recognizing an object located in front, a lane (white line), and the like.

The engine 6 is connected with a throttle valve 8 for controlling the amount of intake air to the engine 6 and adjusting the engine output. More specifically, the throttle valve 8 can automatically adjust the valve opening based on an operation signal output from an electronic control unit (ECU) 50 to be described later according to the opening of an accelerator pedal (not shown) or the like. A simple throttle actuator 12 is provided.

A service brake (braking device) 24 such as a hydraulic disc brake is provided on each of a pair of left and right front wheels (drive wheels) 20 and a pair of right and left rear wheels (sub wheels) 22. Reference numeral 24 is connected to a brake pedal 28 via a brake master cylinder 26 having a negative pressure booster. Further, the brake master cylinder 26 is provided with a negative pressure type brake actuator 30 capable of automatically operating the service brake 24 in response to an operation signal from the ECU 50 regardless of an input from the brake pedal 28.

A wheel speed sensor 32 for detecting a right wheel speed VSR and a left wheel speed VSL is provided in the vicinity of the rear wheels 22, 22, which are slave wheels, corresponding to each wheel.
These wheel speed sensors 32 function as host vehicle speed detecting means for detecting the host vehicle speed Ve.

On a steering column 36 of a steering wheel 34 provided in the cabin of the vehicle 1, a tracking travel switching operation switch 38 for switching a travel control device of the vehicle 1 between a normal traveling state and a traveling state by tracking traveling control is provided. Is provided. When the tracking travel changeover operation switch 38 is operated to the set side, the inter-vehicle distance control, that is, the tracking travel control is started, and when it is operated to the reset side, the inter-vehicle distance control is released.

The ECU 50 is a main control device that controls various controls of the vehicle 1. As shown in the figure, the input side of the ECU 50 is connected to various sensors and switches such as the scanning laser radar 2, the CCD camera 4, the wheel speed sensors 32, 32, and the tracking drive switch 38. ,
Various driving devices such as a throttle actuator 12 and a brake actuator 30 are connected to the output side.

Hereinafter, the control contents of the traveling control device thus configured, that is, the functions and effects according to the present invention will be described.

Referring to FIG. 2, there is shown a flowchart of a tracking drive control routine. Hereinafter, a control procedure of the tracking drive control according to the present invention will be described with reference to FIG.

When the tracking drive switching operation switch 38 is operated to the set side to start the tracking drive control, first, in step S10, a process of determining the preceding vehicle is performed. Specifically, in step S10, when an object is recognized in front of the vehicle 1 based on information from the scanning laser radar 2 and the CCD camera 4, it is determined whether or not the object is a vehicle. If it is determined that the vehicle is a vehicle, the vehicle is determined to be a preceding vehicle. When there are a plurality of preceding vehicles, for example, a vehicle located on the own vehicle lane recognized by the CCD camera 4 or on the own vehicle lane estimated from the own vehicle steering wheel angle is determined as the preceding vehicle. As a result, the preceding vehicle is determined. Since the method of determining the preceding vehicle has no direct relation to the present invention, a detailed description thereof will be omitted.

In step S12, the wheel speed sensor 3
The vehicle speed of the vehicle 1, that is, the host vehicle speed Ve is calculated based on the information from the host vehicles 2 and 32 (host vehicle speed detecting means). Here, the vehicle speed Ve is calculated, for example, by the following equation (1).

Ve = (VSR + VSL) / 2 (1) That is, the own vehicle speed Ve is an average value of the right wheel speed VSR and the left wheel speed VSL.

In step S14, the distance from the own vehicle to the preceding vehicle, that is, the inter-vehicle distance L is accurately measured based on information from the scanning laser radar 2 (inter-vehicle distance detecting means).

In the next step S16, the relative speed Vr between the host vehicle and the preceding vehicle is calculated based on the inter-vehicle distance information L. More specifically, the relative speed Vr is calculated based on the value of the inter-vehicle distance information L when the routine was last executed, that is, the amount of change ΔL between the previous value and the current value. At this time, if the change amount ΔL is positive and the relative speed Vr is positive, it is considered that the own vehicle is moving away from the preceding vehicle. If the change amount ΔL is negative and the relative speed Vr is negative, the own vehicle approaches the preceding vehicle. Can be considered to be.

In step S18, the preceding vehicle speed Vf is calculated from the following equation (2) based on the own vehicle speed Ve and the relative speed Vr (preceding vehicle speed detecting means).

Vf = Ve + Vr (2) Here, the preceding vehicle acceleration αf is also calculated by differentiating the preceding vehicle speed Vf. Specifically, the preceding vehicle acceleration αf is calculated from the change amount ΔVf between the previous value and the current value of the preceding vehicle speed information Vf when the routine was last executed.

In the next step S20, the target deceleration αe of the own vehicle is calculated.

Referring to FIG. 3, there is shown a routine for calculating the target deceleration αe, and the calculation procedure of the target deceleration αe will be described below with reference to the flowchart.

In step S40, first, a target deceleration αer of the own vehicle during deceleration running of the preceding vehicle is calculated from the following equation (3).

Αer = −Vr · Ve / (L−Lo) (3) Here, Lo is secured at a minimum between the host vehicle and the preceding vehicle when it is assumed that the preceding vehicle has decelerated and stopped. Indicates the minimum distance to be driven.

The minimum inter-vehicle distance Lo is equal to the inter-vehicle distance L.
And the inter-vehicle distance L is a value L
If you are more than 1 (for example, 25m) apart,
The minimum inter-vehicle distance Lo is set to a value 0, and when the inter-vehicle distance L becomes less than the value L1, the minimum inter-vehicle distance Lo becomes a value Lo1 (for example, 10
m).

That is, when the inter-vehicle distance L becomes small and the own vehicle approaches the preceding vehicle, the target deceleration αer is increased to secure at least the minimum inter-vehicle distance Lo. They try to avoid contact.

Subsequently, in step S42, the target deceleration αec of the own vehicle while the preceding vehicle is traveling at a constant speed is calculated from the following equation (4) (target deceleration calculating means).

The ^{αec = Vr 2/2 · (} L-Lf · L / La) + αa ... (4) Here, Lf is the target inter-vehicle distance based on the preceding vehicle speed calculated according to the preceding vehicle speed Vf. Specifically, a map indicating the relationship between Vf and Lf as shown in FIG. 4 is preset and stored in the ECU 50, and the target inter-vehicle distance Lf is obtained from the map (target inter-vehicle distance calculating means).

That is, the minimum inter-vehicle distance Lo is equal to the value 0.
, The target inter-vehicle distance Lf1 and the minimum inter-vehicle distance Lo are values Lo1 (for example, 10 m).
Is selected as the target inter-vehicle distance Lf. When the preceding vehicle speed Vf is large, the target inter-vehicle distance Lf becomes the target inter-vehicle distance Lf.
When the preceding vehicle speed Vf decreases, the vehicle speed is set based on the target inter-vehicle distance Lf2 so as to secure at least the minimum inter-vehicle distance Lo.

By the way, the same equation shows that the target inter-vehicle distance Lf is L
/ La is multiplied by another vehicle (interrupted vehicle) between the own vehicle and the preceding vehicle, as shown in FIG.
Is a correction coefficient provided in consideration of a case where the vehicle suddenly breaks in (target inter-vehicle distance reducing means).

Here, La is the vehicle speed Ve and the relative speed Vr.
Is the braking start distance when the own vehicle approaches the preceding vehicle, and Ve, Vr and L as shown in FIG.
This is set based on a map indicating the relationship with a.

In other words, if another vehicle suddenly interrupts, the following distance L indicates a new distance between the other vehicle and the own vehicle, and the new distance L is applied at once. The start distance La is often within the range of the start distance La. In such a case, the braking start distance L of the inter-vehicle distance L is used.
The target inter-vehicle distance Lf is corrected (reduced) according to the degree of interruption to a, that is, L / La (see FIG. 10).

Thus, when another vehicle suddenly interrupts, the target deceleration αer is changed to a small value by reducing the target inter-vehicle distance, and the own vehicle decelerates slowly without sudden braking. become.

That is, referring to FIG. 11, there is shown a time change of the own vehicle speed Ve and the inter-vehicle distance L when another vehicle suddenly interrupts. In FIG. 11, a solid line indicates a target inter-vehicle distance according to L / La. The case where the distance Lf is corrected is shown, and the broken line shows the case where the correction is not performed. By considering L / La, the own vehicle speed Ve is gradually reduced, and the inter-vehicle distance L is temporarily reduced. Will gradually increase overall. Therefore, even if there is an interruption, the occupant of the vehicle 1 is preferably prevented from feeling a deceleration shock.

In the case where the vehicle ahead is satisfactorily tracked without interruption by another vehicle, or after the interruption, the inter-vehicle distance L to the other vehicle gradually increases and becomes larger than the braking start distance La. Correction factor L /
When La exceeds the value 1, the correction coefficient L / La becomes the value 1
The target inter-vehicle distance is set to the normal target inter-vehicle distance Lf based on the map of FIG.

In the above equation, αa is a correction value based on the fluctuation of the preceding vehicle acceleration αf, and is calculated by the following equation (5).

Αa = αf · (L−Le · L / La) / (L−Lf · L / La) (5) where Le is the target inter-vehicle distance during the follow-up control set based on the own vehicle speed Ve. It is. Specifically, as shown in FIG. 6, a map indicating the relationship between Ve and Le similar to that of FIG. 4 is previously set and stored in the ECU 50, and the target inter-vehicle distance Le is obtained from the map.

In the formula for calculating the correction value αa, the target inter-vehicle distance Le and the target inter-vehicle distance Lf are determined by the correction coefficient L
/ La, so that the correction value αa is an appropriate correction value in consideration of interruption of another vehicle.

When the target deceleration αer of the own vehicle during the deceleration running of the preceding vehicle and the target deceleration αec of the own vehicle during the running at a constant speed of the preceding vehicle are obtained as described above, the following steps S44 and S46 are performed. The weights for the target deceleration αer and the target deceleration αec are obtained.

In step S44, first, the preceding vehicle acceleration α
Calculate the weight W1 based on f.

More specifically, a map indicating the relationship between the preceding vehicle acceleration αf and the weight W1 as shown in FIG. 7 is preset and stored in the ECU 50, and the weight W1 is obtained from the map.

That is, the weight W1 gradually increases from the value 0 when the acceleration αf of the preceding vehicle decreases to the negative side, that is, when the deceleration of the preceding vehicle increases and becomes equal to or less than the predetermined value αf1 (for example, -0.05G). , Is set to a value of 1 when a predetermined value αf2 (for example, −0.2 G) is reached.

In step S46, a weight W2 based on the tracking state counter CNT is calculated.

More specifically, a map indicating the relationship between the tracking state counter CNT and the weight W2 as shown in FIG.
2 is determined from the map.

Here, the tracking state counter CNT indicates that the vehicle 1
Is a counter that is incremented every execution cycle of the routine when the vehicle is in the tracking state with respect to the preceding vehicle. When at least the following conditions 1) to 3) are satisfied, it is determined that the vehicle is in the tracking state and is added. I have.

1) (Control state) ≠ (Brake control) 2) L <Le · 3/2 3) | Vr | <Vr1 (for example, 5 km / h) That is, when the vehicle 1 enters the tracking state, the tracking state counter CNT
Is started to be added, but the weight W2 is
The tracking state counter CNT has a predetermined value CNT1 (for example, 0.5 s).
The value is set so as to gradually increase from the value 0 when exceeding a value corresponding to ec, and to become the value 1 when reaching a predetermined value CNT2 (for example, a value corresponding to 2.0 sec). That is, the weight W2 approaches the value 1 as the duration of the tracking state becomes longer.

As described above, when the weight W1 based on the preceding vehicle acceleration αf and the weight W2 based on the tracking state counter CNT are obtained from the respective maps, in the next step S48, the weight W1, the weight W2 and the previous value Wn− The largest one among 1 is selected, and this value is set as the weight W.

In step S50, the weighted average of the target deceleration αer during deceleration running of the preceding vehicle and the target deceleration αec during deceleration running of the preceding vehicle is calculated by taking the weight W into consideration. And the weighted average value is finally set as the target deceleration αe.

Αe = αec · (1−W) + αer · W (6) In this way, by calculating the target deceleration αe by taking the weight W into consideration, for example, the own vehicle can move ahead from a distant vehicle. If the target deceleration αe is switched from the target deceleration αec to the target deceleration αer after decelerating according to the traveling state of the preceding vehicle after traveling at a constant speed in order to catch up with the target deceleration αe
Does not suddenly switch from the target deceleration αec to the target deceleration αer, and the occupant of the vehicle 1 is preferably prevented from feeling uncomfortable.

Therefore, for example, in a situation where the preceding vehicle is running at a constant speed and the own vehicle can catch up with the preceding vehicle from a distance, the preceding vehicle acceleration αf, that is, the preceding vehicle deceleration is small, and
The weight W1 has a value of 0 or its vicinity, and the tracking state counter CNT also does not satisfy the above conditions, so that the weight W2 also has a value of 0 or its vicinity. Therefore, in this case, the weight W is set to the value 0 or its vicinity, and the target deceleration αe is set mainly based on the target deceleration αec.

On the other hand, when the own vehicle catches up with the preceding vehicle and enters the tracking state, the tracking state counter CNT starts to be added, and in this case, the weight W2 and, consequently, the weight W gradually increase, and the target deceleration increases. αe gradually shifts from the target deceleration αec to the target deceleration αer. That is, when the tracking state continues to some extent, the target deceleration αe is switched in advance so as to be gradually calculated based on the target deceleration αer. Therefore, even when the preceding vehicle decelerates thereafter, the target deceleration αe is not suddenly switched, and the occupant is preferably prevented from feeling uncomfortable.

When the preceding vehicle decelerates immediately after the own vehicle catches up with the preceding vehicle and enters the tracking state, the preceding vehicle acceleration αf decreases on the negative side, that is, the preceding vehicle deceleration increases, and the weight of the preceding vehicle decreases. W1 gradually increases. Therefore, in this case, the weight W gradually becomes the value 1 without waiting for the increase of the weight W2, the target deceleration αe is promptly changed, and the target deceleration αec gradually shifts to the target deceleration αer. . Therefore, also in this case, the target deceleration αe is not suddenly switched, and the occupant is preferably prevented from feeling uncomfortable.

By the way, as described above, the target deceleration α
e is calculated, but in the tracking travel control,
In applying the target deceleration αe to actual control, a hysteresis is provided between the output value of the target deceleration αe, that is, the target deceleration output αe-out and the target deceleration input αe-in.

That is, referring to FIG. 9, there is shown a hysteresis relationship (solid arrow) between the target deceleration output αe-out and the target deceleration input αe-in. As shown in FIG. When the deceleration αe increases, the slope K becomes the value 1
(K = 1) and the target deceleration output αe-out is set to the same value as the target deceleration input αe-in, while the target deceleration αe
When the target deceleration input αe-in is equal to or larger than the predetermined value Xi1, the slope K is a value 1 (K = 1) but decreases along the offset line, and the target deceleration input αe-in becomes the predetermined value. When the target deceleration output αe-out is smaller than the value Xi1 and the target deceleration output αe-out is smaller than the predetermined value Xo1, the gradient K becomes equal to the value K1 (K1>
1, e.g., 1.4).

Thus, the normal target deceleration input αe-in
Varies minutely due to changes in the behavior of the preceding vehicle and disturbances due to noise in the signal output from the scanning laser radar 2. Especially when the own vehicle approaches the preceding vehicle, the noise increases and the fluctuation increases. Thus, even in the case where the target deceleration input αe-in fluctuates, the fluctuation of the target deceleration output αe-out, that is, the target deceleration αe is suitably prevented.

Returning to FIG. 2, in step S22, the own vehicle speed Ve detected in step S12 is reduced to a predetermined low vehicle speed Ve0.
(For example, 40 km / h). When the determination result is false (No) and the vehicle speed Ve is equal to or lower than the predetermined low vehicle speed Ve0, the vehicle 1 generally travels in the city, and the driver frequently operates the brake pedal 28. The determination can be made, and the process exits the routine without performing the tracking travel control.

On the other hand, if the decision result in the step S22 is true (Y
If the own vehicle speed Ve is higher than the predetermined low vehicle speed Ve0 in es), the process proceeds to step S24.

In step S24, it is determined whether or not the own vehicle should be decelerated. That is, here, it is determined whether to perform the braking control or the throttle control. More specifically, the braking control is performed when the following conditions 1) to 3) are satisfied.

1) During tracking travel control 2) Vr <0 3) L <La or αer> αer1 That is, in the step S24, the relative speed Vr becomes negative during the tracking travel control, and the inter-vehicle distance L becomes the braking start distance La. Is determined, or whether the target deceleration αer of the own vehicle during deceleration traveling of the preceding vehicle exceeds a predetermined value αer1 set in advance.

The determination result of step S24 is false (No)
If any of the above conditions is not satisfied, the process proceeds to step S26 to perform throttle control. The throttle control is for controlling the throttle actuator 12 according to the running state, but is not directly related to the present invention, so that the description is omitted here.

On the other hand, if the decision result in the step S24 is true (Y
If it is determined in es) that the above conditions are satisfied, the process proceeds to step S28 to execute braking control (braking control means).

In step S28, throttle closing control is performed in executing the braking control. That is, the throttle valve 8 is closed by the throttle actuator 12 to prevent the vehicle 1 from being accidentally accelerated during braking.

In the next step S30, various clip controls are performed. Specifically, in step S28, various clip controls for the target deceleration αe, that is, various limit controls are performed.

As the limiting control of the target deceleration αe, for example, the driver may operate the accelerator pedal (not shown) during the braking control.
To decelerate α after overriding (acceleration)
Limiting control for gradually changing e, tracking running changeover operation switch 3
8 immediately after starting the tracking drive control by operating the target deceleration α
In addition to the limiting control for gradually changing e, the limiting control for tailing immediately after the own vehicle speed Ve becomes equal to or lower than the predetermined low vehicle speed Ve0 (for example, 40 km / h), and the preceding vehicle speed Vf becomes equal to or lower than the predetermined low vehicle speed Vf0. Immediately after the start, there is a limit control for tailing, and a limit control when the inter-vehicle distance L is large. In other words, various limiting controls are performed when the target deceleration αe changes abruptly.

As a result, a sudden change in the target deceleration αe is prevented, and the sudden deceleration of the vehicle 1 and the sudden release of the deceleration state are eliminated.
Tracking running control is realized without discomfort. The details of these various restriction controls are omitted here.

After the various clip controls are performed and the target deceleration αe is appropriately limited by the various limit controls, the process proceeds to step S32.

In step S32, the service brake 2
4 to calculate the braking force to be generated. Specifically, a braking force capable of generating the target deceleration αe determined as described above is calculated, and a signal value to be supplied to the brake actuator 30 is determined according to the braking force.

Then, in step S34, a signal corresponding to the braking force is supplied to the brake actuator 30. As a result, the brake actuator 30 operates properly, and the service brake 24 generates a good and proper braking force.

As described above, in the cruise control device according to the present invention, if another vehicle suddenly cuts in front of the own vehicle within the range of the braking start distance La, the other vehicle will be disconnected. , The target inter-vehicle distance Lf is reduced and corrected based on the degree of interruption of the inter-vehicle distance L with respect to the braking start distance La, that is, L / La.

Therefore, even when another vehicle suddenly cuts in, the own vehicle can be gradually decelerated by temporarily reducing the target inter-vehicle distance and changing the target deceleration αer to a small value. Thus, it is possible to realize the tracking drive control without the occupant feeling the deceleration shock.

Further, in the traveling control device, the target inter-vehicle distance Lf is reduced in accordance with the inter-vehicle distance L, the target inter-vehicle distance always exists, and control is performed with the target inter-vehicle distance as a target.

Therefore, it is possible to preferably prevent the own vehicle from inadvertently approaching the other vehicle that has been interrupted, thereby ensuring good running safety.

[0084]

As described above in detail, according to the vehicle travel control apparatus of the first aspect, the vehicle speed is controlled such that the inter-vehicle distance between the own vehicle and the preceding vehicle becomes the target inter-vehicle distance. In the traveling control device of the vehicle that performs control, the target deceleration of the own vehicle is calculated based on the own vehicle speed, the preceding vehicle speed, the inter-vehicle distance, and the target inter-vehicle distance, and the operation of the braking device is controlled based on the calculated target deceleration. However, when the inter-vehicle distance suddenly becomes shorter than the target inter-vehicle distance and becomes shorter as in the case where another vehicle intervenes between the own vehicle and the preceding vehicle during the tracking driving control, the target inter-vehicle distance becomes smaller. The distance is reduced according to the shortened inter-vehicle distance, and the target deceleration is reduced based on the condensed target inter-vehicle distance.

Therefore, even when another vehicle is interrupted, the own vehicle can be slowly decelerated so that the occupant does not feel a deceleration shock, and smooth tracking driving control can be realized. .

Further, in the traveling control device, by always keeping the target inter-vehicle distance in this way, it is possible to preferably prevent the own vehicle from inadvertently approaching the other interrupted vehicle. It is possible to secure running safety sufficiently.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a traveling control device according to the present invention mounted on a vehicle.

FIG. 2 is a flowchart illustrating a tracking drive control routine according to the present invention.

FIG. 3 is a flowchart showing a routine for calculating a target deceleration αe in FIG. 2;

FIG. 4 shows a preceding vehicle speed Vf and a target inter-vehicle distance Lf based on the preceding vehicle.
It is a map showing the relationship with.

FIG. 5 is a map showing a relationship between a host vehicle speed Ve and a braking start distance La.

FIG. 6 is a map showing a relationship between a host vehicle speed Ve and a target inter-vehicle distance Le.

FIG. 7 is a map showing a relationship between a preceding vehicle acceleration αf and a weight W1.

FIG. 8 is a map showing a relationship between a tracking state counter CNT and a weight W2.

FIG. 9 shows a target deceleration output αe-out and a target deceleration input αe
It is a graph which shows the relationship of the hysteresis between -in.

FIG. 10 is a diagram illustrating a target inter-vehicle distance (Lf · L / La) when another vehicle is interposed between the own vehicle and a preceding vehicle.

FIG. 11 is a diagram illustrating the own vehicle speed Ve (a) and the inter-vehicle distance when control is performed based on a target inter-vehicle distance (Lf · L / La) when another vehicle intervenes between the own vehicle and a preceding vehicle. L
It is a time chart which shows a time change of (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle (own vehicle) 2 Scan type laser radar 24 Service brake (braking device) 28 Brake pedal 30 Brake actuator 32 Wheel speed sensor 38 Tracking drive switching operation switch 50 Electronic control unit (ECU)

Claims (1)

[Claims] 1. A traveling control device for a vehicle, which controls a vehicle speed of a vehicle and controls traveling so that a distance between the vehicle and a preceding vehicle becomes a target vehicle distance, wherein a braking force is automatically applied to the vehicle. A braking device; an inter-vehicle distance detecting means for detecting the inter-vehicle distance; an own vehicle speed detecting means for detecting the own vehicle speed; a preceding vehicle speed detecting means for detecting a preceding vehicle speed; and one of the own vehicle speed and the preceding vehicle speed. Target inter-vehicle distance calculating means for calculating the target inter-vehicle distance based on the own vehicle speed, the preceding vehicle speed, the inter-vehicle distance, and the target inter-vehicle distance, based on target deceleration calculating means for calculating a target deceleration of the own vehicle, When the inter-vehicle distance suddenly decreases from the target inter-vehicle distance,
A target inter-vehicle distance reducing means for reducing the target inter-vehicle distance in accordance with the suddenly reduced inter-vehicle distance; and braking control means for controlling the operation of the braking device based on the target deceleration. Travel control device.