JP2003291685A - Follow-up traveling device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a follow-up traveling device and its control method capable of achieving deceleration properties in accordance with driver's preference with respect to deceleration of a preceding vehicle. <P>SOLUTION: When an operation switch is not operated, deceleration control is executed in accordance with target deceleration Gr calculated by ECU (S2). When the operation switch is operated and an inter-vehicle distance tends to be shortened (YES in S3), the calculated target deceleration Gr is corrected with the usage of correction deceleration data stored in a memory (S4). At this time, the target deceleration Gr is corrected to be larger when the target deceleration Gr is in a way to be increased, and the target deceleration Gr is corrected to be smaller when the target deceleration Gr is in a way to be reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects an inter-vehicle distance between an own vehicle and a preceding vehicle traveling in the same lane, derives a target inter-vehicle distance according to the own vehicle speed, and controls acceleration / deceleration of an acceleration / deceleration means. The present invention relates to a follow-up traveling device that follows a preceding vehicle while maintaining an inter-vehicle distance at a target inter-vehicle distance, and a control method thereof.

[0002]

2. Description of the Related Art A follow-up running device such as an inter-vehicle distance control type constant speed running device, which is mounted as an aid for safe running of an automobile, has conventionally been, for example, 60 m or 10 m when the own vehicle speed is 60 km / h.
The target inter-vehicle distance is determined according to the vehicle speed of the own vehicle, such as 100 m at 0 km / h, and the inter-vehicle distance detecting means including the inter-vehicle distance sensor detects the inter-vehicle distance from the vehicle traveling ahead of the own vehicle. If the preceding vehicle recognizes whether it is a preceding vehicle traveling in the same lane as the own vehicle and determines that the preceding vehicle is the preceding vehicle, control is performed to maintain the inter-vehicle distance with the preceding vehicle at the target inter-vehicle distance. .

At this time, the target acceleration / deceleration is derived from the inter-vehicle distance by the inter-vehicle distance sensor and the relative speed between the own vehicle and the preceding vehicle, and the throttle valve is opened when the target acceleration / deceleration satisfies a certain condition. It accelerates or decelerates by operating a so-called automatic brake such as closing a throttle valve or forcibly operating a brake.

In particular, when the preceding vehicle decelerates and the inter-vehicle distance is shortened, it is necessary to quickly respond to the deceleration of the preceding vehicle, and therefore the acceleration / deceleration of the preceding vehicle (in this case, the deceleration). It has been conventionally practiced to incorporate in the control law.

Specifically, the inter-vehicle distance detected by the inter-vehicle distance sensor is time-differentiated, the speed change of the preceding vehicle is obtained from the differentiation result, and the speed change amount and the speed of the own vehicle detected by the vehicle speed sensor are calculated. Based on this, the relative speed of the preceding vehicle is calculated, and this is further differentiated in time to calculate the relative acceleration / deceleration of the preceding vehicle.In addition to the relative speed and the difference between the target inter-vehicle distance and the actual inter-vehicle distance, the relative acceleration / deceleration is calculated. There is a method in which a target acceleration / deceleration of the own vehicle is obtained by a feedback control law taking speed into consideration, and an automatic brake is operated to decelerate according to the obtained target acceleration / deceleration.

Further, in the case of preventing a rear-end collision, a feed-forward control law, which is a control in which the preceding vehicle and the own vehicle have the same speed at a target distance, that is, the square of the relative speed is calculated as the target vehicle-to-vehicle distance and the actual vehicle-to-vehicle distance. There is a method in which the relative acceleration / deceleration is added to a value divided by the difference from the distance to obtain the target acceleration / deceleration of the own vehicle, and the automatic brake is operated to decelerate according to the obtained target acceleration / deceleration.

[0007]

However, in these methods, since the relative speed obtained by differentiating the inter-vehicle distance is further differentiated to obtain the relative acceleration / deceleration of the preceding vehicle, it is estimated that the noise component is included. Since the accuracy is insufficient, there is a problem that the accuracy of the required target acceleration / deceleration is reduced.

It is also possible to suppress the noise by filtering the relative acceleration / deceleration obtained in this way, but there is the inconvenience that the response is newly deteriorated.

On the other hand, in the case where the driver manually operates the brake, the lighting condition of the stop lamp of the vehicle in front of the preceding vehicle is used as the information for judging the necessity of the brake operation in addition to the lighting condition of the stop lamp of the preceding vehicle. For,
Even if the target acceleration / deceleration can be obtained quickly with good response, the automatic braking may not match the driver's preference especially during deceleration. Specifically, a driver who prefers to start deceleration relatively late and to have a greater degree of deceleration may feel uncomfortable with early automatic braking. Could not be reflected.

Therefore, it is an object of the present invention to provide a follow-up traveling device and a control method thereof capable of realizing a deceleration characteristic that suits a driver's preference with respect to deceleration of a preceding vehicle.

[0011]

In order to achieve the above-mentioned object, a follow-up traveling apparatus according to the present invention detects an inter-vehicle distance between an own vehicle and a preceding vehicle traveling in the same lane, and determines the vehicle distance according to the own vehicle speed. In the following traveling device that derives the target inter-vehicle distance, controls the acceleration / deceleration means to control the acceleration / deceleration, and follows the preceding vehicle while maintaining the inter-vehicle distance at the target inter-vehicle distance, the operating means operated by the driver and the preceding vehicle. And a control means for switching the target deceleration to a greater extent than when the operation means is not operated, provided that the operation means is operated when the inter-vehicle distance tends to be shortened. It is characterized (Claim 1).

According to this structure, when the operating means is operated, the target deceleration can be switched by the control means more than when the operating means is not operated, so that the driver operates according to his / her preference. By operating the means, it is possible to realize a deceleration characteristic that suits the driver's preference.

For example, in the case of a driver who prefers that the deceleration starts relatively late and the degree of deceleration is large, the deceleration start is delayed because the target deceleration increases by operating the operating means. Therefore, it is possible to realize a deceleration characteristic having a large deceleration degree that suits the taste. On the other hand, in the case of a driver who prefers that the deceleration starts relatively early and the deceleration degree is small, the target deceleration does not increase unless the operating means is operated, and the deceleration degree that starts deceleration early is small. You can achieve the desired deceleration characteristics.

Further, the following traveling device according to the present invention determines whether the inter-vehicle distance detecting means for detecting the inter-vehicle distance between the own vehicle and the preceding vehicle and the inter-vehicle distance detected by the inter-vehicle distance detecting means tend to be shortened. The target deceleration of the own vehicle is determined based on the judgment means for judging, the memory means for storing the correction deceleration data of the predetermined pattern set in advance, the inter-vehicle distance detected by the inter-vehicle distance detection means and the speed detected by the vehicle speed detection means. Derivation means for deriving a correction subtraction from the storage means if the control means determines that the detected inter-vehicle distance tends to be shortened by the determination means. It is characterized in that the speed data is read and the target deceleration by the deriving means is corrected (claim 2).

According to this structure, when the determination means determines that the inter-vehicle distance detected by the inter-vehicle distance detection means tends to be shortened, if the operation means operates,
The control means reads the correction deceleration data from the storage means and corrects the target deceleration by the derivation means.

Therefore, in the case of a driver who prefers to start deceleration relatively late and to have a large degree of deceleration, the deceleration characteristic with a large degree of deceleration can be realized by operating the operating means. In the case of a driver who prefers that the deceleration starts relatively early and the degree of deceleration is small, the desired deceleration characteristic with a small degree of deceleration that starts deceleration early can be realized unless the operating means is operated. .

Also, in the following traveling device according to the present invention, the correction deceleration data has a trapezoidal pattern, and the control means is at least increasing the target deceleration by the deriving means. The target deceleration is corrected to be large by utilizing the inclination of the correction deceleration data in the increasing direction (claim 3).

According to this structure, when the target deceleration by the deriving unit is at least increasing, the control unit uses the inclination of the trapezoidal pattern correction deceleration data in the increasing direction. Since the target deceleration is corrected so as to be large, the degree of deceleration can be further increased by operating the operating means, particularly in a large deceleration region.

Further, in the following traveling device according to the present invention, the control means performs the operation unless the detected inter-vehicle distance changes by a predetermined amount or more before a predetermined time elapses after the operation means is operated. It is characterized in that the operation of the means is invalidated (claim 4).

With such a configuration, when there is no change in the inter-vehicle distance by a predetermined amount or more after the operation of the operation means is performed for a predetermined time, the operation of the operation means is enabled to increase the deceleration degree. Since it is not necessary to do so, useless deceleration control can be eliminated by disabling the operation of the operation means.

Further, the control method of the following traveling device according to the present invention detects the inter-vehicle distance between the own vehicle and the preceding vehicle traveling in the same lane, derives the target inter-vehicle distance according to the own vehicle speed, and accelerates / decelerates the vehicle. In a control method of a following traveling device that follows the preceding vehicle while keeping the inter-vehicle distance at the target inter-vehicle distance by controlling acceleration and deceleration, when the inter-vehicle distance with the preceding vehicle tends to be shortened, the driver operates It is characterized in that the target deceleration is switched to a larger value than when the operation means is not operated, provided that the operation means is operable (claim 5).

According to this structure, when the operation means is operated, the target deceleration is switched to a larger level than when the operation means is not operated, and the driver operates the operation means according to his / her preference. Thus, it is possible to realize a deceleration characteristic that suits the driver's taste. For example, in the case of a driver who prefers a greater degree of deceleration when deceleration starts relatively late, by operating the operating means, Since the target deceleration increases, the start of deceleration can be delayed, and a deceleration characteristic with a large degree of deceleration that suits the taste can be realized.

On the other hand, in the case of a driver who prefers that the deceleration starts relatively early and the degree of deceleration is small, the target deceleration does not increase unless the operating means is operated, and deceleration starts early. It is possible to achieve a desired degree of deceleration characteristics with a small degree.

Further, in the control method of the following traveling device according to the present invention, if the detected inter-vehicle distance does not change by a predetermined amount or more before a predetermined time elapses after the operation of the operation means, the operation means is operated. It is characterized in that the presence of the operation is invalidated (claim 6).

According to this structure, when there is no change in the inter-vehicle distance by a predetermined amount or more after the operation of the operation means is performed for a predetermined time, the operation of the operation means is enabled to increase the deceleration degree. Since it is not necessary to do so, useless deceleration control can be eliminated by disabling the operation of the operation means.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. However, FIG. 1 is a block diagram, FIG. 2 is an operation explanatory diagram, and FIGS. 3 and 4 are operation explanatory flowcharts.

As shown in FIG. 1, an inter-vehicle distance sensor 1 including a scanning laser radar as an inter-vehicle distance detecting means detects the inter-vehicle distance between the own vehicle and the preceding vehicle. At this time, the inter-vehicle distance sensor 1 is irradiated with laser light from the semiconductor laser of the scan laser radar in front of the vehicle as described above, and is horizontally scanned by a predetermined angle (for example, 0.1 °) to reflect the reflected light. The distance between the vehicle and the preceding vehicle traveling in the same lane is detected from the time from the light reception by the light receiver to the reception of the reflected light. Such inter-vehicle distance detection is periodically repeated at short time intervals of about 100 ms.

Further, a vehicle speed sensor 2 as a vehicle speed detecting means for detecting the own vehicle speed is provided, and an operating switch 3 as an operating means for switching the degree of deceleration according to the driver's preference and a setting switch for follow-up running control. Various switches including a release switch are provided. Then, each of these sensors 1, 2 and the operation switch 3
Signal from the electronic control unit (hereinafter referred to as ECU)
This is taken in by the ECU 5, and each unit is controlled by the ECU 5.

Specifically, the ECU 5 determines whether the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle based on the result of detection of the inter-vehicle distance by the vehicle distance sensor 1 with respect to the vehicle traveling in front of the own vehicle. If it is determined that the vehicle is the preceding vehicle, the target vehicle distance corresponding to the vehicle speed at that time is based on the vehicle distance detected by the vehicle distance sensor 1 with the preceding vehicle and the vehicle speed detected by the vehicle speed sensor 2. , The relative speed and the relative deceleration with respect to the preceding vehicle are derived, and the target deceleration Gr of the own vehicle is derived.

At this time, the ECU 5 sets the relative speed of the traveling vehicle to ΔV, the distance difference between the target inter-vehicle distance and the actual inter-vehicle distance after a predetermined time period is ΔD, and the relative deceleration of the preceding vehicle is α and K1. , K2, K3 as constants, the target acceleration / deceleration Gr of the own vehicle is calculated on the basis of these by, for example, the calculation of the formula Gr = ΔV * K1 + ΔD * K2 + α * K3. Here, the derivation process of the target deceleration Gr by the ECU 5 corresponds to the derivation means in the present invention.

Further, the ECU 5 determines whether or not the detected inter-vehicle distance with the preceding vehicle detected by the inter-vehicle distance sensor 1 tends to be shortened. When it is determined that the inter-vehicle distance tends to be shortened, the operation switch 3 is operated. On condition that there is such a change, the target deceleration Gr is switched to a larger value than when the operation switch 3 is not operated. Here, the process of determining whether the detected inter-vehicle distance tends to be shortened by the ECU 5 corresponds to the determining means in the present invention.

More specifically, as the correction deceleration data, for example, the correction deceleration data having a trapezoidal pattern as shown by a broken line in FIG. 2 is rewritable RO as a storage means.
If the operation switch 3 is operated when the ECU 5 determines that the detected inter-vehicle distance tends to be shortened, the ECU 5 stores the correction deceleration from the memory 6 beforehand. The target deceleration Gr derived by reading the data is corrected.

At this time, as shown in FIG. 2, when the target deceleration Gr is increasing, the ECU 5 causes the memory 6 to operate.
Using the inclination of the correction deceleration data in the increasing direction to correct the target deceleration Gr to be larger, that is, the deceleration degree to be larger, while the target deceleration Gr is decreasing, Using the inclination of the correction deceleration data in the memory 6 in the decreasing direction, the target deceleration Gr is corrected to be smaller, that is, the deceleration degree is smaller. As a result, the target deceleration Gr as shown by the solid line in FIG. 2 is corrected as shown by the alternate long and short dash line in FIG.

Further, if there is no change in the detected inter-vehicle distance by a predetermined amount or more within a predetermined time t after the operation of the operation switch 3, the ECU 5 operates the operation switch 3 The operation for correcting the target deceleration Gr is invalidated even if the operation of the operation switch 3 is ignored.

In this way, the ECU 5 controls the electronic throttle 7 and the brake actuator 8 which are acceleration / deceleration means according to the obtained target acceleration / deceleration Gr of the own vehicle, and closes the electronic throttle 7 or forcibly operates the brake actuator 8. Then, the automatic brake is operated to perform deceleration control. During acceleration, the ECU 5 controls to open the electronic throttle 7. A series of control processes such as the correction of the target deceleration Gr by the ECU 5 corresponds to the control means.

Further, as shown in FIG. 1, an alarm buzzer, an alarm lamp, an LCD for displaying a predetermined message, or an informing section 10 including a combination thereof is provided, and the inter-vehicle distance to the preceding vehicle is the target inter-vehicle distance. The ECU 5 controls the notification unit 10 when it is too close to
The notification unit 10 operates and issues a warning to the driver.

Next, the operation will be described with reference to the flowcharts of FIGS. 3 and 4.

First, the procedure for judging the necessity of correcting the target deceleration Gr will be described. As shown in FIG. 3, it is judged whether or not the operation switch 3 is operated (S).
1) If the determination result is NO, deceleration control according to the target deceleration Gr calculated by the ECU 5 is executed (S2), and then this operation ends.

On the other hand, if the decision result in the step S1 is YES, it is decided whether or not the inter-vehicle distance detected by the inter-vehicle distance sensor 1 tends to be shortened (S3), and if the decision result is NO, the above is performed. If the determination result is YES in step S2, the calculated target deceleration Gr is corrected using the correction deceleration data stored in the memory 6 as described above (S4), The operation ends.

Next, the procedure of correcting the target deceleration Gr will be described. As shown in FIG. 4, it is determined whether the target deceleration Gr is increased or decreased (S11). As a result of this determination, the target deceleration Gr must be unchanged. If the target deceleration Gr is decreasing as a result of the determination (see FIG. 2), the inclination of the correction deceleration data stored in the memory 6 in the decreasing direction is used. The target deceleration Gr is corrected to be small (S12), and then this operation ends.

On the other hand, if the result of determination in step S11 is that the target deceleration Gr is increasing (see FIG. 2), the inclination of the correction deceleration data stored in the memory 6 in the increasing direction is used. The target deceleration Gr is corrected to be large (S13), and the maximum correction value corresponding to the base of the trapezoid of the correction deceleration data shown by the broken line in FIG. 2 is guaranteed (S1).
4) After that, this operation ends.

As described above, when the operation switch 3 is operated, the ECU 5 causes the target deceleration Gr to be changed.
Since the switching can be performed more largely than when there is no operation, the driver operates the operation switch 3 according to his / her preference, so that the deceleration characteristic according to his / her preference is realized.

Therefore, according to the above-described embodiment, when the operation switch 3 is operated, the target deceleration Gr is switched more than when the operation switch 3 is not operated, and the driver operates according to his / her preference. By operating the switch 3, it is possible to realize a deceleration characteristic that suits one's own preference. For example, in the case of a driver who prefers a large deceleration degree starting deceleration relatively late, Since the target deceleration Gr is increased by operating the switch 3, it is possible to delay the start of deceleration, and it is possible to realize a deceleration characteristic having a large degree of deceleration that matches the taste.

On the other hand, in the case of a driver who prefers that deceleration starts relatively early and the degree of deceleration is small, the target deceleration Gr does not increase unless the operation switch 3 is operated, and deceleration starts early. A desired deceleration characteristic with a small degree of deceleration can be realized.

If there is no change in the inter-vehicle distance by a predetermined amount or more after the operation of the operation switch 3 for a predetermined time, it is not necessary to enable the operation of the operation switch 3 to increase the deceleration degree. Since it is in the state, it is possible to eliminate useless deceleration control by disabling the operation of the operation switch 3.

In the above-described embodiment, when the target deceleration Gr is decreasing, the target deceleration Gr is corrected to be small by utilizing the inclination of the correction deceleration data in the decreasing direction. The target deceleration Gr
It is needless to say that control may be performed so that the correction process is immediately stopped when starts to show a decreasing tendency.

Further, in the above-described embodiment, the presence of the operation of the operation switch 3 is invalidated if the detected inter-vehicle distance does not change by a predetermined amount or more before the predetermined time elapses after the operation of the operation switch 3 is performed. However, such processing does not necessarily have to be performed.

In the above embodiment, the case where the correction deceleration data has a trapezoidal pattern has been described, but it goes without saying that the correction deceleration data need not have a trapezoidal shape.

Further, in the above embodiment, the case where the inter-vehicle distance detecting means is the inter-vehicle distance sensor 1 composed of the scan laser radar has been described, but the inter-vehicle distance detecting means is limited to such inter-vehicle distance sensor 1. Of course, the operation means is not limited to the operation switch 3 described above.

The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

[0051]

As described above, according to the first and fifth aspects of the present invention, when the operating means is operated, the target deceleration is switched more than when the operating means is not operated, and the driver is By operating the operating means in accordance with one's own preference, it is possible to realize a deceleration characteristic that suits the driver's preference. For example, a driver who prefers a deceleration that starts relatively late and a large deceleration degree. In this case, since the target deceleration is increased by operating the operating means, it is possible to delay the start of deceleration and it is possible to realize a deceleration characteristic with a large degree of deceleration that suits the user's preference.

On the other hand, in the case of a driver who prefers that the deceleration starts relatively early and the degree of deceleration is small, the target deceleration does not increase unless the operating means is operated, and deceleration starts early. To provide a follow-up traveling device and a control method thereof that can realize a deceleration characteristic with a small degree as desired and can realize a deceleration characteristic that suits a driver's preference with respect to deceleration of a preceding vehicle. You can

Further, according to the second aspect of the invention, in the case of a driver who prefers a greater degree of deceleration by starting deceleration relatively late, the deceleration degree can be controlled by operating the operating means. While it is possible to realize a large deceleration characteristic, in the case of a driver who prefers that deceleration starts relatively early and the degree of deceleration is small, the deceleration degree at which deceleration starts early unless the operating means is operated. It is possible to realize a deceleration characteristic that is as small as desired.

According to the third aspect of the present invention, when the target deceleration by the deriving unit is at least increasing, the control unit causes the trapezoidal pattern correction deceleration data to increase. Since the target deceleration is corrected using the inclination so as to be large, it is possible to further increase the deceleration degree by operating the operating means, particularly in a large deceleration region.

According to the fourth and sixth aspects of the present invention, when the inter-vehicle distance does not change by a predetermined amount or more before the predetermined time elapses after the operation means is operated, the operation means is operated. Since there is no need to enable it and increase the degree of deceleration, it is possible to eliminate useless deceleration control by disabling the operation of the operating means.

[Brief description of drawings]

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

FIG. 2 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 3 is a flowchart explaining the operation of the embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

1 Inter-vehicle distance sensor (inter-vehicle distance detection means) 3 Operation switch (operation means) 5 ECU (determination means, derivation means, control means) 6 memory (storage means) 7 Electronic throttle (acceleration / deceleration means) 8 Brake actuator (acceleration / deceleration means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60R 21/00 B60R 21/00 626E 627 627 B60T 7/12 B60T 7/12 C F F02D 29/02 301 F02D 29/02 301D G08G 1/16 G08G 1/16 EF Term (reference) 3D044 AA04 AA25 AB01 AC26 AC28 AC59 AD04 AD21 AE01 AE04 AE14 AE21 3D046 BB18 GG02 HH02 HH20 HH22 HH26 3G093 BA23 FA11 CB04 FA02 EC02 DB02 FB01 FB02 5H180 AA01 CC03 CC14 LL07 LL08 LL09

Claims (6)

[Claims] 1. A vehicle-to-vehicle distance between a host vehicle and a preceding vehicle traveling in the same lane is detected, a target vehicle-to-vehicle distance is derived according to the vehicle speed, and acceleration / deceleration means is controlled to control the vehicle-to-vehicle distance. In the following traveling device that follows the preceding vehicle while keeping the following distance, the operating means operated by the driver and the operating means being operated when the following distance between the preceding vehicle and the preceding vehicle tends to be shortened. A follow-up traveling apparatus, characterized in that the control means further comprises a control means for switching the target deceleration to a larger level than when the operation means is not operated. 2. An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and the preceding vehicle; a determining means for determining whether or not the inter-vehicle distance detected by the inter-vehicle distance detecting means tends to be shortened; And a derivation unit for deriving a target deceleration of the own vehicle from a vehicle distance detection unit and a vehicle speed detection unit. When the control means determines that the detected inter-vehicle distance tends to be shortened by the determination means, and if the operation means is operated, the correction deceleration data is read from the storage means and the derivation means is used. The follow-up traveling device according to claim 1, wherein the target deceleration is corrected. 3. The correction deceleration data has a trapezoidal pattern, and the control means increases the correction deceleration data when the target deceleration by the deriving means is at least increasing. The follow-up traveling apparatus according to claim 2, wherein the target deceleration is corrected to be increased by utilizing the inclination in the direction. 4. The control means invalidates the presence of the operation of the operation means unless the detected inter-vehicle distance changes by a predetermined amount or more before a predetermined time elapses after the operation of the operation means. The following traveling device according to any one of claims 1 to 3. 5. The inter-vehicle distance between the own vehicle and a preceding vehicle traveling in the same lane is detected, a target inter-vehicle distance is derived according to the own vehicle speed, and acceleration / deceleration control is performed to control the inter-vehicle distance. In a control method of a follow-up traveling device that follows the preceding vehicle while keeping the inter-vehicle distance, when there is a tendency that the inter-vehicle distance with the preceding vehicle tends to be shortened, the operation means operable by a driver is operated. A method for controlling a following traveling device, wherein the target deceleration is switched to a larger value than when the operation means is not operated. 6. The operation of the operating means is invalidated if the detected inter-vehicle distance does not change by a predetermined amount or more within a predetermined time after the operation of the operating means is performed. Item 6. A control method for the following traveling device according to Item 5.