JP2007137148A - Apparatus for travel control of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the frequent repetition of the acceleration and deceleration of driver's own vehicle even if a preceding vehicle frequently repeats the acceleration and deceleration during the following travel control for making the driver's own vehicle travel so as to follow the preceding vehicle. <P>SOLUTION: During the following travel control (control of distance between two vehicles), whether or not the preceding vehicle frequently repeats the acceleration and deceleration is judged depending upon whether or not the number of times of the acceleration and deceleration of the preceding vehicle per a required period of time is more than a reference value. When it has been judged that the preceding vehicle is frequently repeating the acceleration and deceleration, the driver's own vehicle is controlled so as to keep the vehicle speed constant by switching-over the following travel control to the constant speed following control if the actual distance between two vehicles is within a dead zone determined so as to be in the range from (a target distance between two vehicles -α) to (the target distance between two vehicles +β). As a result, even if the preceding vehicle has frequently repeated the acceleration and deceleration, the frequent repetition of the acceleration and deceleration of the driver's own vehicle by following the preceding vehicle can be prevented. After that, when the actual distance between two vehicles has come out of the dead zone, the driver's own vehicle is controlled so as to keep the actual distance between two vehicles to be the target distance between two vehicles by returning the control to the ordinary control for the distance between two vehicles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a travel control device for a vehicle having a function of controlling the host vehicle to follow the vehicle while detecting the inter-vehicle distance with respect to a preceding vehicle.

  In recent electronically controlled vehicles, the actual inter-vehicle distance between the own vehicle and the preceding vehicle is detected based on the output of a laser radar sensor or the like, and the own vehicle is maintained so that the actual inter-vehicle distance is maintained at the target inter-vehicle distance. There is one in which the own vehicle is made to follow the preceding vehicle by controlling.

  However, in follow-up running control that simply maintains the actual inter-vehicle distance at the target inter-vehicle distance, if the actual inter-vehicle distance is longer than the target inter-vehicle distance, the host vehicle is accelerated even if the preceding vehicle is decelerating. When the inter-vehicle distance is shorter than the target inter-vehicle distance, the host vehicle may be decelerated even if the preceding vehicle is accelerating, so it does not match the driver's feeling and makes the driver feel uncomfortable. There is.

As a countermeasure, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-10003), the target inter-vehicle distance and the target acceleration / deceleration state of the host vehicle are adjusted according to the acceleration / deceleration state of the preceding vehicle and the host vehicle. Thus, there is one that performs follow-up running control that matches the driver's feeling.
Japanese Patent Laid-Open No. 2004-10003 (second page, etc.)

  However, in the follow-up running control described in Patent Document 1, when the preceding vehicle frequently repeats acceleration / deceleration due to a driver's brake operation, accelerator operation, etc. during low-speed running, the host vehicle is controlled to follow it. Since the host vehicle frequently repeats acceleration / deceleration, there is a drawback that ride comfort and fuel consumption are reduced.

  The present invention has been made in view of such circumstances. Therefore, even if the preceding vehicle frequently repeats acceleration / deceleration, the object of the present invention is to frequently repeat acceleration / deceleration following the acceleration / deceleration. It is an object of the present invention to provide a travel control device for a vehicle that can prevent this and improve ride comfort and fuel consumption.

  In order to achieve the above object, the invention according to claim 1 is directed to an inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle and the preceding vehicle based on a detection value of the inter-vehicle distance detecting means. In the vehicle travel control device, the vehicle travel control device is configured to control the vehicle to follow the vehicle while ensuring the inter-vehicle distance, and the acceleration / deceleration state of the preceding vehicle is calculated by the acceleration / deceleration state calculation unit. Based on the acceleration / deceleration state of the vehicle, whether the preceding vehicle frequently repeats acceleration / deceleration is determined by the acceleration / deceleration determining unit, and when it is determined that the preceding vehicle frequently repeats acceleration / deceleration, A dead zone is set so that the distance is wide, and constant speed tracking control is performed to control the vehicle to run at a constant vehicle speed if the distance between the vehicle and the preceding vehicle is within the dead zone. In which was to so that.

  In this way, even if the preceding vehicle repeats frequent acceleration / deceleration, if the actual inter-vehicle distance is within the dead zone for increasing the target inter-vehicle distance, the vehicle travels at a constant vehicle speed by constant speed tracking control. Therefore, when the preceding vehicle frequently repeats acceleration / deceleration due to the driver's brake operation, accelerator operation, etc., it is possible to prevent the host vehicle from repeating acceleration / deceleration following the acceleration and deceleration. And fuel consumption can be improved. For example, even if the preceding vehicle frequently repeats acceleration / deceleration, if the preceding vehicle is traveling at a constant speed on average, the ride speed and fuel consumption can be greatly improved by the constant speed tracking control. it can.

  In this case, the acceleration / deceleration repetition speed determining means calculates the number of times of acceleration / deceleration per predetermined time of the preceding vehicle, and the preceding vehicle is frequently used based on the number of acceleration / deceleration per predetermined time of the preceding vehicle. It may be determined whether acceleration / deceleration is repeated. In short, if the preceding vehicle frequently repeats acceleration / deceleration, the number of times of acceleration / deceleration per predetermined time of the preceding vehicle increases. Therefore, if the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is monitored, the preceding vehicle frequently accelerates / decelerates. Can be accurately determined.

  Alternatively, as in claim 3, the acceleration / deceleration repetition period or frequency of the preceding vehicle is calculated, and whether or not the preceding vehicle repeats acceleration / deceleration frequently based on the acceleration / deceleration repetition period or frequency of the preceding vehicle. You may make it determine. In short, if the preceding vehicle frequently repeats acceleration / deceleration, the repetition cycle (time interval) of the preceding vehicle shortens and the frequency increases, so if you monitor the repetition cycle and frequency of the preceding vehicle, It can be accurately determined whether the preceding vehicle frequently repeats acceleration / deceleration.

  By the way, the width of the dead zone of the target inter-vehicle distance (that is, the range of the actual inter-vehicle distance in which constant speed tracking control is executed) may be fixed to a preset range. You may make it set the width | variety of a dead zone according to the acceleration / deceleration rate at the time of repeating acceleration / deceleration and / or a vehicle speed. In short, since the safe inter-vehicle distance changes according to the acceleration / deceleration rate and vehicle speed when the preceding vehicle repeats acceleration / deceleration, if the dead zone width is set according to the acceleration / deceleration rate and vehicle speed of the preceding vehicle, The width of the dead zone can be appropriately changed so that a safe inter-vehicle distance can be ensured according to the acceleration / deceleration rate and the vehicle speed, and both safety and follow-up running performance can be achieved.

  Further, as in claim 5, the target vehicle speed of the constant speed tracking control may be set based on the vehicle speed / acceleration / deceleration history of the preceding vehicle during the constant speed tracking control. In short, considering the vehicle speed and acceleration / deceleration history of the preceding vehicle, the appropriate target vehicle speed for the vehicle to follow at a constant speed while ensuring a safe inter-vehicle distance with respect to the preceding vehicle during the constant speed tracking control is obtained. Can be set.

  Further, during the execution of the constant speed tracking control, when the actual inter-vehicle distance deviates from the dead zone, the tracking driving control (constant speed tracking control and normal inter-vehicle distance control) may be canceled to return to manual operation. However, as in claim 6, when the actual inter-vehicle distance deviates from the dead zone, it is preferable to switch to normal inter-vehicle distance control that controls the host vehicle so that the actual inter-vehicle distance matches the target inter-vehicle distance. In this way, when the actual inter-vehicle distance deviates from the dead zone, switching to normal inter-vehicle distance control can automatically prevent the host vehicle from being too close or too far from the preceding vehicle.

  Further, as described in claim 7, when it is determined that the preceding vehicle frequently repeats acceleration / deceleration, the following traveling control may be canceled (cancelled). Even if it does in this way, when a preceding vehicle repeats acceleration / deceleration frequently, it can prevent that the own vehicle repeats acceleration / deceleration frequently following it, and can improve riding comfort and fuel consumption.

  Also in this case, as in claim 8, it may be determined whether or not the preceding vehicle frequently repeats acceleration / deceleration based on the number of times of acceleration / deceleration per predetermined time of the preceding vehicle. Or you may make it determine whether the preceding vehicle repeats acceleration / deceleration frequently based on the repetition period or frequency of acceleration / deceleration of a preceding vehicle like Claim 9.

  Further, as in claim 10, when the acceleration / deceleration of the preceding vehicle is frequently repeated at an acceleration / deceleration rate equal to or greater than a predetermined value, it may be determined that the preceding vehicle frequently repeats acceleration / deceleration. . In short, even if the preceding vehicle frequently repeats acceleration / deceleration, if the acceleration / deceleration is small, continuing tracking control does not have a significant effect on ride comfort and fuel consumption, but rather continues tracking control. This is more likely to be in line with the driver's intention than switching to manual operation. However, if acceleration / deceleration of the preceding vehicle is frequently repeated with a large acceleration / deceleration, if the follow-up running control is continued as it is, the vehicle follows the preceding vehicle and frequently repeats acceleration / deceleration with a large acceleration / deceleration. The adverse effects on ride comfort and fuel efficiency increase, making the driver feel uncomfortable. Therefore, in this case, as described in claim 10, it is more in line with the driver's intention to cancel the follow-up running control and switch to manual driving than to continue the follow-up running control. Get better.

  Further, as in the eleventh aspect, when the follow-up running control is canceled, it is preferable to notify the driver of the fact by the notification means. In this way, the driver can be surely notified that the follow-up running control is released.

  Hereinafter, the best mode for carrying out the present invention will be described using two Examples 1 and 2.

A first embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the entire vehicle control system will be described with reference to FIG. The output of the engine 11 that is an internal combustion engine mounted on the vehicle is transmitted to the drive wheels of the vehicle via an automatic transmission or the like. The throttle valve for adjusting the intake air amount of the engine 11 is adjusted by the throttle motor 12.

  Further, a laser radar sensor 13 (inter-vehicle distance detection means) for detecting the actual inter-vehicle distance between the host vehicle and the preceding vehicle is attached to the front surface of the vehicle. Instead of the laser radar sensor 13, an inter-vehicle distance detection means for detecting the inter-vehicle distance using radio waves or sound waves may be attached. Furthermore, a wheel speed sensor 14 for detecting a wheel speed is attached to a wheel of the vehicle, and an acceleration sensor 15 for detecting an acceleration in the front-rear direction of the vehicle is attached to a predetermined position of the vehicle.

  Outputs of these various sensors are input to a control circuit (hereinafter referred to as “ECU”) 16. The ECU 16 is composed of one or a plurality of microcomputers including an engine ECU 17 and a follow-up travel control ECU 18 and the like, and an engine control program (not shown) is executed by the engine ECU 17 so that the engine can be operated according to the engine operating state. The fuel injection valve 11 and the ignition timing of the spark plug are controlled.

  Further, the ECU 16 causes the following vehicle to follow the preceding vehicle by executing a following traveling control program shown in FIG. 3 described later in the following traveling control ECU 18 when the following traveling mode is set by the driver's operation or the like. The follow-up running control that is controlled as described above is executed as follows.

  First, based on the output of the laser radar sensor 13, the actual inter-vehicle distance between the host vehicle and the preceding vehicle [see FIG. 2 (a)] is calculated. Furthermore, the vehicle speed V1 of the host vehicle calculated based on the actual inter-vehicle distance, the output of the wheel speed sensor 14, and the vehicle speed V2 of the preceding vehicle based on the acceleration (acceleration / deceleration) of the host vehicle detected by the acceleration sensor 15. Acceleration (acceleration / deceleration) is calculated, and a target inter-vehicle distance [see FIG. 2 (a)] for safely following the vehicle based on the vehicle speeds V1, V2 and acceleration of the host vehicle and the preceding vehicle is set. The acceleration sensor 15 may be omitted and the acceleration of the host vehicle may be calculated based on the amount of change in the vehicle speed V1 per unit time of the host vehicle. In addition, the setting method of the target inter-vehicle distance may be changed as appropriate. For example, the target inter-vehicle distance is considered in consideration of the steering angle of the own vehicle (that is, the degree of curvature of the traveling road), the inclination angle of the own vehicle (that is, the road surface gradient), etc. May be corrected.

  During normal time in the follow-up travel mode, normal inter-vehicle distance control is executed as shown in FIG. In this normal inter-vehicle distance control, the vehicle output V1 and acceleration of the own vehicle are controlled by controlling the engine output of the own vehicle and the gear ratio of the automatic transmission so that the actual inter-vehicle distance matches the target inter-vehicle distance.

  However, when the preceding vehicle frequently repeats acceleration / deceleration by the driver's brake operation or accelerator operation during the follow-up driving mode, if the vehicle repeats acceleration / deceleration frequently following that, the ride comfort and fuel consumption will decrease. There is a problem.

  As a countermeasure, in the first embodiment, first, the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is calculated during the follow-up running mode, and whether the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is equal to or greater than a determination value. Thus, it is determined whether the preceding vehicle frequently repeats acceleration / deceleration. Here, the number of times of acceleration / deceleration is, for example, the number of times the acceleration is switched from positive to negative or the number of times the acceleration is switched from negative to positive. Alternatively, the total number of times that the acceleration has been switched from positive to negative and the number of times that the acceleration has been switched from negative to positive may be used. In any case, when determining whether the acceleration is positive to negative or negative to positive, it is preferable that the determination threshold value (acceleration = 0) has a certain dead zone.

  If the preceding vehicle frequently repeats acceleration / deceleration, the number of times of acceleration / deceleration per predetermined time of the preceding vehicle increases. Therefore, if the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is compared with the judgment value, the preceding vehicle frequently increases. It can be accurately determined whether or not the deceleration is repeated.

  If it is determined that the preceding vehicle frequently repeats acceleration / deceleration, it is determined whether or not the actual inter-vehicle distance is within a dead zone set so as to give a width to the target inter-vehicle distance. As shown in FIG. 2C, this dead zone is set, for example, in a range from “target inter-vehicle distance−predetermined value α” to “target inter-vehicle distance + predetermined value β”.

  When it is determined that the preceding vehicle frequently repeats acceleration / deceleration, if the actual inter-vehicle distance is within the dead zone, constant speed tracking control is executed as shown in FIG. In this constant speed tracking control, for example, the vehicle speed V1 of the host vehicle immediately before the start of the constant speed tracking control is set as the target vehicle speed, and the engine output of the host vehicle is maintained so that the vehicle speed V1 of the host vehicle is maintained at the target vehicle speed (a constant value). And control the gear ratio of the automatic transmission. Accordingly, even if the preceding vehicle frequently repeats acceleration / deceleration, the host vehicle is prevented from frequently repeating acceleration / deceleration following the acceleration / deceleration.

  Note that the dead zone widths α and β of the target inter-vehicle distance (that is, the actual inter-vehicle distance range in which the constant speed tracking control is executed) may be fixed to a preset value, but the preceding vehicle frequently repeats acceleration / deceleration. The dead zone widths α and β may be set according to the acceleration / deceleration rate and / or the vehicle speed. In short, since the safe inter-vehicle distance changes according to the acceleration / deceleration rate and vehicle speed V2 when the preceding vehicle repeats acceleration / deceleration, the dead zone widths α and β are set according to the acceleration / deceleration rate of the preceding vehicle and the vehicle speed V2. For example, the widths α and β of the dead zone can be appropriately changed so that a safe inter-vehicle distance can be secured according to the acceleration / deceleration speed of the preceding vehicle and the vehicle speed V2, and both safety and follow-up driving performance can be achieved. it can.

  Further, when setting the target vehicle speed for constant speed tracking control, as described above, the vehicle speed V1 of the host vehicle immediately before the start of constant speed tracking control may be set as the target vehicle speed. Based on the history, the target vehicle speed of the constant speed tracking control may be set to an average vehicle speed at the time of repeated acceleration / deceleration of the preceding vehicle. In short, considering the vehicle speed and acceleration / deceleration history of the preceding vehicle, the appropriate target vehicle speed for the vehicle to follow at a constant speed while ensuring a safe inter-vehicle distance with respect to the preceding vehicle during the constant speed tracking control is obtained. Can be set.

  When the target vehicle speed for constant speed tracking control is set to the average vehicle speed during repeated acceleration / deceleration of the preceding vehicle, the actual vehicle speed V1 of the vehicle at the beginning of the constant speed tracking control may deviate from the target vehicle speed. Therefore, it is preferable to perform control so that the actual vehicle speed V1 of the host vehicle gradually approaches the target vehicle speed from the start of constant speed tracking control. Thereby, it is possible to avoid sudden acceleration / deceleration at the start of constant speed tracking control.

Hereinafter, the processing content of the following traveling control program of FIG. 3 executed by the ECU 16 (following traveling control ECU 18) will be described.
The follow-up running control program shown in FIG. 3 is executed at a predetermined cycle during the follow-up running mode, and plays a role as follow-up running control means in the claims. When this program is started, first, in step 101, the vehicle state quantity such as the vehicle speed of the host vehicle calculated based on the output of the wheel speed sensor 14 or the acceleration (acceleration / deceleration) of the host vehicle detected by the acceleration sensor 15 is determined. Is read.

  Thereafter, the process proceeds to step 102, where the actual inter-vehicle distance between the own vehicle and the preceding vehicle is calculated based on the output of the laser radar sensor 13, and the actual inter-vehicle distance and the vehicle speed or acceleration (acceleration / deceleration) of the own vehicle are calculated. After calculating the vehicle speed and acceleration (acceleration / deceleration) of the preceding vehicle based on this, the process proceeds to step 103, and the target inter-vehicle distance is calculated based on the vehicle speed and acceleration (acceleration / deceleration) of the host vehicle and the preceding vehicle.

  Thereafter, the process proceeds to step 104, and the number of times of acceleration / deceleration per predetermined time of the preceding vehicle (for example, the acceleration is switched from positive to negative and / or from negative to positive based on the behavior of the acceleration (acceleration / deceleration) of the preceding vehicle. Number of times). The processing in step 104 serves as acceleration / deceleration state calculation means in the claims.

  Thereafter, the process proceeds to step 105, where it is determined whether the preceding vehicle frequently repeats acceleration / deceleration based on whether the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is greater than or equal to a determination value. The processing in step 105 serves as acceleration / deceleration repetition determination means in the claims.

  If it is determined in step 105 that the preceding vehicle frequently repeats acceleration / deceleration, the process proceeds to step 106, where the actual inter-vehicle distance ranges from “target inter-vehicle distance−α” to “target inter-vehicle distance + β”. It is determined whether or not it is within the dead zone set to.

  In step 105, it is determined that the preceding vehicle frequently repeats acceleration / deceleration (the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is greater than or equal to a determination value), and in step 106, the actual inter-vehicle distance is a dead zone. If it is determined that the vehicle speed is within the range, the routine proceeds to step 107, where the current vehicle speed (that is, immediately before the start of the constant speed tracking control) is set as the target vehicle speed of the constant speed tracking control.

  Thereafter, the process proceeds to step 108, where constant speed tracking control is executed to control the engine output of the host vehicle and the gear ratio of the automatic transmission so that the vehicle speed of the host vehicle matches the target vehicle speed. Accordingly, even if the preceding vehicle frequently repeats acceleration / deceleration, the host vehicle is prevented from frequently repeating acceleration / deceleration following the acceleration / deceleration.

  On the other hand, if it is determined in step 105 that the preceding vehicle does not frequently repeat acceleration / deceleration (the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is less than the determination value), or in step 106, If it is determined that the actual inter-vehicle distance is out of the dead zone, the routine proceeds to step 109, where the normal inter-vehicle distance control is executed, and the engine output of the host vehicle is adjusted so that the actual inter-vehicle distance matches the target inter-vehicle distance. To control the vehicle speed and acceleration of the host vehicle.

  In the first embodiment described above, it is determined whether the preceding vehicle frequently repeats acceleration / deceleration depending on whether the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is greater than or equal to a determination value. When it is determined that acceleration / deceleration is frequently repeated, if the actual inter-vehicle distance is within the dead zone of the target inter-vehicle distance, switching to constant speed tracking control is performed so that the host vehicle is maintained at the target vehicle speed. As a result, it is possible to prevent the vehicle from repeating repeated acceleration / deceleration following the acceleration / deceleration when the preceding vehicle frequently repeats acceleration / deceleration due to the driver's brake operation or accelerator operation. Comfort and fuel consumption can be improved.

  Moreover, when the actual inter-vehicle distance deviates from the dead zone, the constant-speed tracking control is canceled and switched to the normal inter-vehicle distance control, and the host vehicle is controlled so that the actual inter-vehicle distance matches the target inter-vehicle distance. It is possible to reliably prevent the vehicle from approaching or leaving too far from the preceding vehicle beyond the dead zone, and to ensure followability with respect to the preceding vehicle.

Next, Embodiment 2 of the present invention will be described with reference to FIG.
In the second embodiment, it is determined that the preceding vehicle frequently repeats acceleration / deceleration by executing the following traveling control cancellation program of FIG. 4 during the following traveling mode, and the acceleration / deceleration rate of the preceding vehicle is predetermined. When it is determined that the value is greater than or equal to the value, the following traveling control is canceled (cancelled) and switched to manual operation. The technology for canceling the follow-up running control may be implemented in combination with the follow-up running control described in the first embodiment, or may be implemented in combination with other follow-up running control.

  The follow-up running control program shown in FIG. 4 is executed at a predetermined cycle during the follow-up running mode, and plays a role as follow-up running control canceling means in the claims. When this program is started, it is first determined in step 201 whether or not follow-up running control is being executed. If follow-up running control is being executed, the process proceeds to step 202 and the acceleration (acceleration / deceleration) of the preceding vehicle is determined. The number of times of acceleration / deceleration per predetermined time of the preceding vehicle (for example, the number of times the acceleration is switched from positive to negative and / or negative to positive) is calculated based on the behavior of the vehicle.

  Thereafter, the process proceeds to step 203, where it is determined whether the preceding vehicle frequently repeats acceleration / deceleration based on whether the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is greater than or equal to a determination value. If it is determined in step 203 that the preceding vehicle frequently repeats acceleration / deceleration, the process proceeds to step 204, and whether the acceleration / deceleration rate when the preceding vehicle frequently repeats acceleration / deceleration is greater than or equal to a predetermined value. Determine whether or not.

  In step 203, it is determined that the preceding vehicle frequently repeats acceleration / deceleration (the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is greater than or equal to a determination value), and in step 204, the acceleration / deceleration of the preceding vehicle is determined. If the result is determined to be greater than or equal to a predetermined value, it is determined that the preceding vehicle or road condition is abnormal, it is determined that it is better not to continue the follow-up running control, and the process proceeds to step 205 to cancel the follow-up running control. To do.

  Thereafter, the process proceeds to step 206, where a warning lamp (not shown) provided on the instrument panel of the driver's seat is turned on, or a warning is displayed on a warning display portion (not shown) of the instrument panel of the driver's seat. Then, the driver is warned by notifying that the follow-up running control has been released. The process of step 206 serves as a notification means in the claims.

  In the second embodiment described above, when it is determined that the preceding vehicle frequently repeats acceleration / deceleration, and the acceleration / deceleration at the time of repeated acceleration / deceleration is determined to be greater than or equal to a predetermined value, the following traveling control is canceled. Since it did in this way, it can prevent that the own vehicle repeats acceleration / deceleration frequently following the preceding vehicle, and can improve riding comfort and fuel consumption.

  In this second embodiment, even if it is determined that the preceding vehicle frequently repeats acceleration / deceleration, if it is determined that the acceleration / deceleration rate at the time of repeated acceleration / deceleration is smaller than the “predetermined value”, the follow-up traveling control is performed as it is. Will continue. In short, even if the preceding vehicle frequently repeats acceleration / deceleration, if the acceleration / deceleration is small, continuing tracking control does not have a significant effect on ride comfort and fuel consumption, but rather continues tracking control. This is more likely to be in line with the driver's intention than switching to manual operation. However, if acceleration / deceleration of the preceding vehicle is frequently repeated with a large acceleration / deceleration, if the follow-up running control is continued as it is, the vehicle follows the preceding vehicle and frequently repeats acceleration / deceleration with a large acceleration / deceleration. The adverse effects on ride comfort and fuel efficiency increase, making the driver feel uncomfortable. Therefore, in this case, as in the second embodiment, when the follow-up running control is canceled and switched to the manual driving, the driver's intention is satisfied rather than the follow-up running control is continued. Also gets better.

However, it goes without saying that in the present invention, when it is determined that the preceding vehicle frequently repeats acceleration / deceleration, the following traveling control may be immediately canceled.
In each of the first and second embodiments, the number of times of acceleration / deceleration per predetermined time of the preceding vehicle is compared with the determination value to determine whether the preceding vehicle frequently repeats acceleration / deceleration. The vehicle acceleration / deceleration repetition period and frequency may be compared with a determination value to determine whether the preceding vehicle frequently repeats acceleration / deceleration. If the preceding vehicle frequently repeats acceleration / deceleration, the acceleration / deceleration repetition period (time interval) of the preceding vehicle is shortened and the frequency is increased. Therefore, if the repetition period and frequency of the preceding vehicle are compared with the judgment value, It is possible to accurately determine whether the preceding vehicle frequently repeats acceleration / deceleration.

It is a schematic block diagram of the whole vehicle control system in Example 1 of this invention. (A) is a figure explaining the actual inter-vehicle distance and the target inter-vehicle distance, (b) is a figure explaining the normal inter-vehicle distance control, and (c) is a figure explaining the constant speed tracking control. It is a flowchart which shows the flow of a process of the follow-up driving control program of Example 1. It is a flowchart which shows the flow of a process of the follow driving control cancellation program of Example 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Engine (internal combustion engine), 13 ... Laser radar sensor (vehicle distance detection means), 14 ... Wheel speed sensor, 15 ... Acceleration sensor, 16 ... ECU, 17 ... Engine ECU, 18 ... Follow-up running control ECU (follow-up running control) Means, acceleration / deceleration state calculation means, acceleration / deceleration repetition determination means, follow-up running control release means, notification means)

Claims (11)

An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle, and controlling the own vehicle to follow the vehicle while ensuring the inter-vehicle distance based on a detection value of the inter-vehicle distance detecting means. In the vehicle travel control device comprising the following travel control means,
Acceleration / deceleration state calculating means for calculating the acceleration / deceleration state of the preceding vehicle;
Acceleration / deceleration repetition determination means for determining whether the preceding vehicle frequently repeats acceleration / deceleration based on the acceleration / deceleration state of the preceding vehicle calculated by the acceleration / deceleration state calculation means;
The follow-up travel control means sets a dead zone so that the target inter-vehicle distance is widened when the acceleration / deceleration repetition determination means determines that the preceding vehicle frequently repeats acceleration / deceleration, A vehicle travel control apparatus that performs constant speed tracking control for controlling the host vehicle to travel at a constant vehicle speed if the distance between the vehicle and the vehicle is within the dead zone. The acceleration / deceleration state calculating means calculates the number of times of acceleration / deceleration per predetermined time of the preceding vehicle,
2. The vehicle according to claim 1, wherein the acceleration / deceleration repetition speed determination unit determines whether the preceding vehicle frequently repeats acceleration / deceleration based on the number of times of acceleration / deceleration per predetermined time of the preceding vehicle. Travel control device. The acceleration / deceleration state calculating means calculates a repetition cycle or frequency of acceleration / deceleration of the preceding vehicle,
2. The vehicle according to claim 1, wherein the acceleration / deceleration repetition determining unit determines whether the preceding vehicle frequently repeats acceleration / deceleration based on a repetition cycle or frequency of acceleration / deceleration of the preceding vehicle. Travel control device.   The said following travel control means sets the width | variety of the said dead zone according to the acceleration / deceleration degree and / or vehicle speed when a preceding vehicle repeats acceleration / deceleration frequently. Vehicle travel control device.   5. The follow-up running control unit sets a target vehicle speed for the constant-speed follow-up control based on a vehicle speed / acceleration / deceleration history of a preceding vehicle during the constant-speed follow-up control. The vehicle travel control device according to claim 1.   2. The follow-up traveling control means switches to normal inter-vehicle distance control for controlling the actual inter-vehicle distance to coincide with the target inter-vehicle distance when the actual inter-vehicle distance deviates from the dead zone. The vehicle travel control device according to any one of claims 5 to 5. An inter-vehicle distance detecting means for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle, and controlling the own vehicle to follow the vehicle while ensuring the inter-vehicle distance based on a detection value of the inter-vehicle distance detecting means. In the vehicle travel control device comprising the following travel control means,
Acceleration / deceleration state calculating means for calculating the acceleration / deceleration state of the preceding vehicle;
Acceleration / deceleration repetition determining means for determining whether the preceding vehicle frequently repeats acceleration / deceleration based on the acceleration / deceleration state of the preceding vehicle calculated by the acceleration / deceleration state calculating means;
And following traveling control release means for releasing the following traveling control by the following traveling control means when it is determined by the acceleration / deceleration repetition determining means that the preceding vehicle frequently repeats acceleration / deceleration. A vehicle travel control device. The acceleration / deceleration state calculating means calculates the number of times of acceleration / deceleration per predetermined time of the preceding vehicle,
8. The vehicle according to claim 7, wherein the acceleration / deceleration repetition speed determination unit determines whether the preceding vehicle frequently repeats acceleration / deceleration based on the number of times of acceleration / deceleration per predetermined time of the preceding vehicle. Travel control device. The acceleration / deceleration state calculating means calculates a repetition cycle or frequency of acceleration / deceleration of the preceding vehicle,
8. The vehicle according to claim 7, wherein the acceleration / deceleration repetition determining unit determines whether the preceding vehicle frequently repeats acceleration / deceleration based on an acceleration / deceleration repetition period or frequency of the preceding vehicle. Travel control device.   The acceleration / deceleration repetition determining means determines that the preceding vehicle frequently repeats acceleration / deceleration when acceleration / deceleration of the preceding vehicle is frequently repeated at an acceleration / deceleration rate equal to or greater than a predetermined value. Item 10. The vehicle travel control device according to any one of Items 7 to 9.   The vehicle travel control device according to claim 7, further comprising a notification unit that notifies the fact that the following travel control is canceled by the following travel control canceling unit.

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