JP2009248683A - Following distance control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a following distance control device which inhibits change of target following distance which is contrary to intention of a driver. <P>SOLUTION: The following distance control device which controls a vehicle to regulate a distance to a preceding vehicle to a target following distance includes: at least one operation detection means out of an acceleration operation detection means which detects acceleration operation by the driver and a deceleration operation detection means which detects deceleration operation by the driver; a vehicle speed detection means; and a target following distance change means which changes the target following distance in a plurality of steps based on the following distance when terminating acceleration operation or when terminating deceleration operation by the driver which is detected by the operation detection means, and inhibits change of the target following distance by the target following distance setting means when the vehicle speed detected by the vehicle speed detection means is not more than the threshold value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inter-vehicle distance control device that controls a vehicle so that an inter-vehicle distance from a preceding vehicle becomes a target inter-vehicle distance.

In the inter-vehicle distance control device, vehicle control (throttle control, brake control, etc.) is performed so that the inter-vehicle distance from the preceding vehicle becomes the target inter-vehicle distance so that the host vehicle follows the preceding vehicle. In the devices described in Patent Documents 1 and 2, the inter-vehicle distance control is stopped when a brake operation or an accelerator operation by the driver is started during the inter-vehicle distance control, and the inter-vehicle distance control is returned when the operation is completed. In particular, in this apparatus, when the inter-vehicle distance control is returned, the inter-vehicle distance control is performed using the actual inter-vehicle distance at the time of the return as the target inter-vehicle distance. Further, in the apparatus described in Patent Document 3, the target inter-vehicle distance is changed when the driver's intention to shorten the inter-vehicle distance or the intention to increase the inter-vehicle distance is detected by the driver's brake operation or accelerator operation during inter-vehicle distance control. . For example, the intention of shortening the inter-vehicle distance is detected by an accelerator operation of a predetermined amount or more and an accelerator operation changing to a decreasing tendency after the accelerator operation, and the intention of increasing the inter-vehicle distance is a brake operation of a predetermined amount or more and after the brake operation. It is detected by the accelerator operation that changes to an increasing trend.
JP 2004-216964 A JP 2004-216965 A JP 2004-306690 A

  Usually, the target inter-vehicle distance is set according to the host vehicle speed, and the appropriate target inter-vehicle distance is longer as the speed is higher and shorter as the speed is lower. In addition, as for the target inter-vehicle distance, a plurality of target inter-vehicle distances may be prepared at the same own vehicle speed so that the target inter-vehicle distance desired by the driver can be set. In such a case, the higher the host vehicle speed, the longer the target inter-vehicle distance, and thus the difference in distance between the target inter-vehicle distances in multiple stages becomes large. On the other hand, since the target inter-vehicle distance is shorter as the host vehicle speed is lower, the distance difference between the target inter-vehicle distances in a plurality of stages becomes smaller. Therefore, when the vehicle speed is low, the target inter-vehicle distance at a certain stage is selected from the multiple target inter-vehicle distances based on the actual inter-vehicle distance adjusted by the driver's brake operation or accelerator operation. Since the target inter-vehicle distance at a different stage is selected with a slight difference in inter-vehicle distance, the target inter-vehicle distance at a stage contrary to the driver's intention may be selected. When the target inter-vehicle distance at a stage contrary to the driver's intention is selected in this way, the higher the own vehicle speed, the farther the driver's desired inter-vehicle distance will be at the selected target vehicle speed distance. become.

  Then, this invention makes it a subject to provide the inter-vehicle distance control apparatus which prevents the change of the target inter-vehicle distance contrary to a driver | operator's intention.

  An inter-vehicle distance control device according to the present invention is an inter-vehicle distance control device that controls a vehicle such that an inter-vehicle distance from a preceding vehicle becomes a target inter-vehicle distance, and includes an acceleration operation detecting unit that detects an acceleration operation of a driver and driving Based on at least one operation detection means of a deceleration operation detection means for detecting a deceleration operation of the driver, a vehicle speed detection means, and an inter-vehicle distance at the end of the acceleration operation or deceleration operation of the driver detected by the operation detection means And a target inter-vehicle distance changing unit that changes the target inter-vehicle distance in a stage, and suppresses a change in the target inter-vehicle distance by the target inter-vehicle distance setting unit when the vehicle speed detected by the vehicle speed detecting unit is equal to or less than a threshold value.

  In this inter-vehicle distance control device, the acceleration operation detecting means detects the driver's acceleration operation and / or the deceleration operation detection means detects the driver's deceleration operation. In the inter-vehicle distance control device, the target inter-vehicle distance changing means changes the target inter-vehicle distance in a plurality of stages based on the inter-vehicle distance at the end of the acceleration operation or the deceleration operation. The appropriate target inter-vehicle distance is longer at higher speeds and shorter at lower speeds. As the target inter-vehicle distance, a plurality of target inter-vehicle distances are prepared at the same vehicle speed. Therefore, when the vehicle speed is low, the target inter-vehicle distance is shortened, so that the difference in distance between the target inter-vehicle distances in a plurality of stages is reduced, and there is a possibility that the target inter-vehicle distance is changed to a stage contrary to the driver's intention. Therefore, the target inter-vehicle distance is unlikely to be changed at a vehicle speed level at which there is a possibility that the distance between the target inter-vehicle distances in a plurality of stages becomes small and the target inter-vehicle distance is contrary to the driver's intention. Therefore, in the inter-vehicle distance control device, the vehicle speed is detected by the vehicle speed detecting means, and the change of the target inter-vehicle distance by the target inter-vehicle distance setting means is suppressed when the detected vehicle speed is equal to or less than the threshold value. As described above, in this inter-vehicle distance control device, when the vehicle speed is equal to or lower than the threshold value, the change of the target inter-vehicle distance can be prevented by suppressing the change of the target inter-vehicle distance.

  The driver's acceleration operation detected by the acceleration operation detecting means may be one that detects the operation of the accelerator pedal itself by the driver, or other throttle opening, acceleration, etc. according to the accelerator pedal operation. A parameter may be detected. As for the driver's deceleration operation detected by the deceleration operation detecting means, the driver's operation of the brake pedal itself may be detected, or other parameters such as brake hydraulic pressure and deceleration according to the brake pedal operation may be set. It may be detected. Examples of the suppression of the change in the target inter-vehicle distance include prohibition of the change in the target inter-vehicle distance and change to an intermediate value between the originally set target inter-vehicle distance and the new target inter-vehicle distance.

  According to the present invention, when the vehicle speed is equal to or lower than the threshold value, the change of the target inter-vehicle distance can be prevented by suppressing the change of the target inter-vehicle distance.

  Embodiments of an inter-vehicle distance control device according to the present invention will be described below with reference to the drawings.

  In the present embodiment, the inter-vehicle distance control device according to the present invention is applied to an ACC [Adaptive Cruise Control] device mounted on a vehicle. In the ACC device according to the present embodiment, when there is a preceding vehicle before the host vehicle, the preceding vehicle follow-up control is performed so that the inter-vehicle distance from the preceding vehicle becomes the target inter-vehicle distance, and there is no preceding vehicle. The constant speed control is performed so that the own vehicle speed becomes the target vehicle speed.

  With reference to FIG.1 and FIG.2, the ACC apparatus 1 which concerns on this Embodiment is demonstrated. FIG. 1 is a configuration diagram of an ACC device according to the present embodiment. FIG. 2 is an example of a target inter-vehicle distance map used in the ACC ECU of FIG.

  The ACC device 1 performs the vehicle speed control based on the target inter-vehicle distance extracted according to the own vehicle speed from the target inter-vehicle distance map during the preceding vehicle following control, and further the inter-vehicle distance corresponding to the accelerator operation and the brake operation by the driver. The target inter-vehicle distance map is changed based on the distance and the own vehicle speed. In particular, the ACC device 1 prohibits the change of the target inter-vehicle distance map when the host vehicle speed is low so as not to change to the target inter-vehicle distance map contrary to the driver's intention.

  The ACC device 1 includes a millimeter wave radar 10, a vehicle speed sensor 11, an accelerator pedal sensor 12, a brake pedal sensor 13, an ACC switch 14, an engine control ECU [Electronic Control Unit] 20, a brake control ECU 21, and an ACC ECU 30.

  In this embodiment, the accelerator pedal sensor 12 corresponds to the acceleration operation detecting means described in the claims, the brake pedal sensor 13 corresponds to the deceleration operation detecting means described in the claims, and the vehicle speed sensor 11 and the processing in the ACC ECU 30 correspond to the vehicle speed detection means described in the claims, and the processing in the ACC ECU 30 corresponds to the target inter-vehicle distance changing means described in the claims.

  The millimeter wave radar 10 is a radar for detecting an object using millimeter waves. The millimeter wave radar 10 is attached to the front center of the host vehicle. The millimeter wave radar 10 transmits the millimeter wave forward while scanning the millimeter wave in a horizontal plane, and receives the reflected millimeter wave. The millimeter wave radar 10 transmits the millimeter wave transmission / reception information to the ACCUCU 30 as a radar signal.

  The vehicle speed sensor 11 is a wheel speed sensor that detects the rotational speed of the wheel. The vehicle speed sensor 11 transmits the rotation speed to the ACC ECU 30 as a vehicle speed signal. The ACC ECU 30 calculates the vehicle speed from the rotational speed of the wheels.

  The accelerator pedal sensor 12 is a sensor that detects the amount of depression (accelerator opening) of an accelerator pedal (not shown). The accelerator pedal sensor 12 transmits the detected depression amount to the ACC ECU 30 as an accelerator pedal signal.

  The brake pedal sensor 13 is a sensor that detects the amount of depression of a brake pedal (not shown). The brake pedal sensor 13 transmits the detected depression amount to the ACC ECU 30 as a brake pedal signal.

  The ACC switch 14 is a switch for performing operations such as on (start) / off (stop) of the ACC device 1. The ACC switch 14 transmits operation information performed by the driver to the ACC ECU 30 as an ACC switch signal.

  The engine control ECU 20 is a control device that controls the engine (and thus the driving force). The engine control ECU 20 sets a target acceleration based on an accelerator operation by the driver. Then, the engine control ECU 20 sets a target opening of the throttle valve necessary for achieving the target acceleration, and transmits the target opening as a target throttle opening signal to a throttle actuator (not shown). In particular, when the engine control ECU 20 receives an engine control signal from the ACC ECU 30, the engine control ECU 20 transmits a target throttle opening signal for achieving the target acceleration indicated by the engine control signal to the throttle actuator.

  The throttle actuator is an actuator that adjusts the opening of a throttle valve (not shown). The throttle actuator operates according to a target throttle opening signal from the engine control ECU 20, and adjusts the opening of the throttle valve. When the target throttle opening is reached, the vehicle has the target acceleration set by the engine control ECU 20 and the target vehicle speed.

  The brake control ECU 21 is a control device that controls each brake (and thus the braking force). The brake control ECU 21 sets a target deceleration based on a brake operation by the driver. The brake control ECU 21 sets the brake hydraulic pressure of each wheel cylinder (not shown) necessary for achieving the target deceleration, and uses the brake hydraulic pressure as a target hydraulic pressure signal to the brake actuator (not shown). Send. In particular, when the brake control ECU 21 receives a brake control signal from the ACC ECU 30, the brake control ECU 21 transmits a target hydraulic pressure signal for achieving the target deceleration indicated by the brake control signal to the brake actuator.

  The brake actuator is an actuator that adjusts the brake hydraulic pressure of the wheel cylinder of each wheel. The brake actuator operates according to a target hydraulic pressure signal from the brake control ECU 21 and adjusts the brake hydraulic pressure of the wheel cylinder. When the target hydraulic pressure is reached, the vehicle has the target deceleration set by the brake control ECU 21 and the target vehicle speed.

  The ACC ECU 30 is an electronic control unit including a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and comprehensively controls the ACC device 1. The ACC ECU 30 activates the ACC device 1 when the driver turns on the ACC switch 14 based on the ACC switch signal from the ACC switch 14, and the driver activates the ACC switch 14 while the ACC device 1 is operating. When the off operation is performed on the ACC device 1, the ACC device 1 is stopped.

  While the ACC device 1 is operating, the ACC ECU 30 takes in various signals from the various sensors 10, 11, 12, 13 and changes the preceding vehicle determination control, the preceding vehicle follow-up control, the constant speed control, and the target inter-vehicle distance map based on the various signals. Permit control, target inter-vehicle distance map change control, etc. The ACC ECU 30 sets a target acceleration / deceleration and transmits a control signal to the engine control ECU 20 and the brake control ECU 21 based on the target acceleration or the target deceleration. The target acceleration / deceleration is expressed as a positive value / negative value. When the value is positive, acceleration control (driving force control) is performed using the target acceleration. When the value is negative, deceleration control (braking force control) is performed using the target deceleration. It is.

  The ROM of the ACC ECU 30 stores a target inter-vehicle distance map used in the preceding vehicle following control. As shown in FIG. 2, the target inter-vehicle distance map is a map showing the inter-vehicle distance (target inter-vehicle distance) corresponding to the own vehicle speed, and a longer inter-vehicle distance is set as the own vehicle speed increases. As the target inter-vehicle distance map, a multi-level map is prepared in which different target inter-vehicle distances can be set at the same own vehicle speed so that the driver can set the desired inter-vehicle distance. From the plurality of target inter-vehicle distance maps, the target inter-vehicle distance map closest to the intersection of the actual own vehicle speed and inter-vehicle distance is selected. For example, when the host vehicle speed is V1 and the inter-vehicle distance is L1 when the ACC device 1 is activated, the target inter-vehicle distance map M1 closest to the intersection P1 of the host vehicle speed V1 and the inter-vehicle distance L1 is selected. . During the preceding vehicle following control, when the host vehicle speed becomes V2, L2 is extracted as the target inter-vehicle distance from the target inter-vehicle distance map M1.

  The preceding vehicle determination control will be described. The ACC ECU 30 determines the presence / absence of a vehicle (preceding vehicle) traveling ahead of the host vehicle based on the radar signal from the millimeter wave radar 10 at regular time intervals. At this time, the traveling direction of the host vehicle is estimated from the steering angle, the yaw rate, etc., and the presence / absence of a preceding vehicle is determined in consideration of the traveling direction of the host vehicle. When there is a preceding vehicle, the ACC ECU 30 calculates an inter-vehicle distance between the own vehicle and the preceding vehicle based on the radar signal at regular intervals.

  The preceding vehicle following control will be described. When there is a preceding vehicle, the ACC ECU 30 extracts the target inter-vehicle distance according to the host vehicle speed from the selected target inter-vehicle distance map at regular time intervals. Then, the ACC ECU 30 sets the target acceleration / deceleration necessary for the inter-vehicle distance to the preceding vehicle to be the target inter-vehicle distance based on the difference between the inter-vehicle distance from the preceding vehicle and the target inter-vehicle distance at regular time intervals. When the target acceleration / deceleration is a positive value, the ACC ECU 30 sets a target acceleration and transmits the target acceleration to the engine control ECU 20 as an engine control signal. When the target acceleration / deceleration is a negative value, the ACC ECU 30 sets the target deceleration and transmits the target deceleration to the brake control ECU 21 as a brake control signal.

  The constant speed control will be described. When there is no preceding vehicle, the ACC ECU 30 sets a target acceleration / deceleration necessary for the host vehicle speed to become the target vehicle speed based on the difference between the host vehicle speed and the target vehicle speed at regular time intervals. When the target acceleration / deceleration is a positive value, the ACC ECU 30 sets a target acceleration and transmits the target acceleration to the engine control ECU 20 as an engine control signal. When the target acceleration / deceleration is a negative value, the ACC ECU 30 sets the target deceleration and transmits the target deceleration to the brake control ECU 21 as a brake control signal. As the target vehicle speed, for example, the driver may set by a function provided in the ACC switch 14, or the own vehicle speed when the ACC device 1 is activated may be set.

  The target inter-vehicle distance map change permission control will be described. As can be seen from FIG. 2, in the target inter-vehicle distance map at all stages, the inter-vehicle distance is set so as to become longer as the speed becomes higher and shorter as the speed becomes lower. Therefore, the higher the host vehicle speed, the longer the inter-vehicle distance of each target inter-vehicle distance map, and the greater the difference in distance between the multiple target inter-vehicle distance maps. On the other hand, the lower the vehicle speed, the shorter the inter-vehicle distance in each target inter-vehicle distance map, and the smaller the difference in distance between the target inter-vehicle distance maps in a plurality of stages. Therefore, when the host vehicle speed is low, even if the actual inter-vehicle distance adjusted by the driver is slightly different, the target inter-vehicle distance map at different stages is selected. If the target inter-vehicle distance map that the driver wants when the host vehicle speed is low is not selected, the inter-vehicle distance that is not so far from the target inter-vehicle distance that the driver wants when the host vehicle speed is low, The higher the host vehicle speed, the greater the inter-vehicle distance far from the target inter-vehicle distance desired by the driver. Thus, if the target inter-vehicle distance map is changed when the host vehicle speed is low, the target inter-vehicle distance map at a stage contrary to the driver's intention may be selected. Therefore, when the host vehicle speed is low, selection of the target inter-vehicle distance map is prohibited.

  Specifically, the ACC ECU 30 determines whether or not the own vehicle speed calculated based on the vehicle speed signal from the vehicle speed sensor 11 is higher than a threshold value at regular intervals during the preceding vehicle following control. The threshold value is a threshold value for determining a vehicle speed level at which a difference in distance between the target inter-vehicle distance maps in a plurality of stages is small and a target inter-vehicle distance map that is contrary to the driver's intention may be selected. The threshold value is set in advance by experiments or the like, and is, for example, a vehicle speed of about 20 km / h.

  When the host vehicle speed is higher than the threshold value, the ACC ECU 30 permits the change of the target inter-vehicle distance map by the accelerator operation and the brake operation (that is, the target inter-vehicle distance map change control is executed). On the other hand, when the host vehicle speed is equal to or lower than the threshold value, the ACC ECU 30 prohibits the change of the target inter-vehicle distance map by the accelerator operation and the brake operation (that is, the target inter-vehicle distance map change control is not executed).

  The target inter-vehicle distance map change control will be described. The target inter-vehicle distance map change control is executed when the change is permitted by the target inter-vehicle distance map change permission control. The target inter-vehicle distance map can be changed in accordance with the reduction in the inter-vehicle distance due to the accelerator operation or in accordance with the increase in the inter-vehicle distance due to the brake operation. These will be described in order.

  A case of the accelerator operation will be described. Basically, when the driver performs an accelerator operation (that is, an operation for accelerating and reducing the inter-vehicle distance), the target inter-vehicle distance map is changed according to the actual inter-vehicle distance and the own vehicle speed immediately after the accelerator operation is completed. . Specifically, the ACC ECU 30 determines whether or not the accelerator pedal is depressed (whether or not the accelerator is ON) based on the accelerator pedal signal at regular intervals during the preceding vehicle following control. Then, while the accelerator is ON, the ACC ECU 30 determines whether or not the depression of the accelerator pedal is completed (whether the accelerator is switched from ON to OFF) based on the accelerator pedal signal at regular intervals. When the accelerator is switched from ON to OFF, the ACC ECU 30 selects a target inter-vehicle distance map that is closest to the intersection of the actual inter-vehicle distance immediately after the accelerator operation is completed and the own vehicle speed.

  A case where the brake is operated will be described. Basically, when the driver performs a brake operation (that is, an operation for decelerating and increasing the inter-vehicle distance), the actual inter-vehicle distance immediately after the end of the brake operation and the target inter-vehicle distance map according to the own vehicle speed are changed. . Specifically, the ACC ECU 30 determines whether or not the brake pedal is depressed (whether or not the brake is ON) based on the brake pedal signal at regular intervals during the preceding vehicle following control. Then, while the brake is ON, the ACC ECU 30 determines whether or not the depression of the brake pedal has been completed (whether the brake has been switched from ON to OFF) based on the brake pedal signal at regular intervals. When the brake is switched from ON to OFF, the ACC ECU 30 selects the target inter-vehicle distance map that is closest to the intersection of the actual inter-vehicle distance immediately after the end of the brake operation and the host vehicle speed.

  With reference to FIG.1 and FIG.2, the operation | movement in the ACC apparatus 1 is demonstrated. In particular, the target inter-vehicle distance map change permission control in the ACC ECU 30 will be described with reference to the flowchart of FIG. FIG. 3 is a flowchart showing a flow of target inter-vehicle distance map change permission control in the ACC ECU of FIG.

  The ACC switch 14 transmits operation information performed by the driver to the ACC ECU 30 as an ACC switch signal. If it determines with the driver | operator having performed ON operation with respect to the ACC switch 14 based on this ACC switch signal, ACC ECU30 will start the ACC apparatus 1 and will start each control.

  The millimeter wave radar 10 transmits and receives millimeter waves, and transmits the transmitted and received information to the ACCU ECU 30 as radar signals. The vehicle speed sensor 11 detects the rotational speed of the wheel and transmits the rotational speed to the ACC ECU 30 as a vehicle speed signal. The accelerator pedal sensor 12 detects the depression amount of the accelerator pedal, and transmits the detected depression amount to the ACC ECU 30 as an accelerator pedal signal. The brake pedal sensor 13 detects the depression amount of the brake pedal, and transmits the detected depression amount to the ACC ECU 30 as a brake pedal signal.

  The ACC ECU 30 receives various signals from the sensors 10, 11, 12, and 13 at regular intervals. Then, the ACC ECU 30 determines the presence or absence of a preceding vehicle based on the radar signal, and calculates an inter-vehicle distance from the preceding vehicle if a preceding vehicle exists. Further, the ACC ECU 30 calculates the host vehicle speed and the like based on the vehicle speed signal. When the ACC device 1 is activated, the ACC ECU 30 selects a target inter-vehicle distance map from the intersection of the inter-vehicle distance at the time of activation and the host vehicle speed. However, when there is no preceding vehicle, the target inter-vehicle distance map is not selected because the inter-vehicle distance is not calculated.

  When there is a preceding vehicle, the ACC ECU 30 extracts the target inter-vehicle distance according to the host vehicle speed from the target inter-vehicle distance map at regular time intervals by the preceding vehicle following control, and is necessary for the inter-vehicle distance to be the target inter-vehicle distance. Set the target acceleration / deceleration. When the target acceleration / deceleration is a positive value, the ACC ECU 30 transmits an engine control signal indicating the target acceleration to the engine control ECU 20. When this engine control signal is received, the engine control ECU 20 transmits a target throttle opening signal for achieving the target acceleration indicated by the engine control signal to the throttle actuator. When the target throttle opening signal is received, the throttle actuator operates in accordance with the target throttle opening signal to adjust the throttle valve opening. When the target throttle opening is reached, the vehicle becomes the target acceleration and the target vehicle speed. When the target acceleration / deceleration is a negative value, the ACC ECU 30 transmits a brake control signal indicating the target deceleration to the brake control ECU 21. When this brake control signal is received, the brake control ECU 21 transmits a target hydraulic pressure signal for achieving the target deceleration indicated by the brake control signal to the brake actuator. When receiving the target hydraulic pressure signal, the brake actuator operates according to the target hydraulic pressure signal to adjust the brake hydraulic pressure of the wheel cylinder. When the target hydraulic pressure is reached, the target vehicle speed is reduced to the target vehicle speed. As a result, the own vehicle is adjusted so that the inter-vehicle distance from the preceding vehicle becomes the target inter-vehicle distance.

  When there is no preceding vehicle, the ACC ECU 30 sets the target acceleration / deceleration necessary for the host vehicle speed to become the target vehicle speed at regular intervals by constant speed control. Based on this target acceleration / deceleration, the ACC ECU 30, the engine control ECU 20 (throttle actuator, throttle valve), and the brake control ECU 21 (brake actuator, wheel cylinder) perform the same operation as the preceding vehicle following control. Thus, the host vehicle is adjusted so that the host vehicle speed becomes the target vehicle speed.

  The ACC ECU 30 determines whether or not the preceding vehicle follow-up control is being performed at regular time intervals (S10). If it is determined in S10 that the preceding vehicle follow-up control is not being performed, the ACC ECU 30 ends the current process.

  If it is determined in S10 that the preceding vehicle follow-up control is being performed, the ACC ECU 30 determines whether or not the own vehicle speed calculated based on the vehicle speed signal is higher than a threshold value at regular time intervals (S11).

  If it is determined in S11 that the host vehicle speed is higher than the threshold value, the ACC ECU 30 permits the change of the target inter-vehicle distance map by the accelerator operation and the brake operation (S12).

  When it is determined in S11 that the host vehicle speed is equal to or less than the threshold value, the ACC ECU 30 prohibits the change of the target inter-vehicle distance map by the accelerator operation and the brake operation (S13). At this time, the target inter-vehicle distance map that was originally selected is maintained.

  When the change of the target inter-vehicle distance map by the accelerator operation and the brake operation is permitted, the ACC ECU 30 determines whether or not the accelerator is ON based on the accelerator pedal signal at regular intervals. If it is determined that the accelerator is switched from ON to OFF after it is determined that the accelerator is ON, the ACC ECU 30 selects a target inter-vehicle distance map corresponding to the inter-vehicle distance immediately after being switched to OFF and the host vehicle speed. Further, the ACC ECU 30 determines whether or not the brake is ON based on the brake pedal signal at regular intervals. When it is determined that the brake has been switched from ON to OFF after the brake is determined to be ON, the ACC ECU 30 selects a target inter-vehicle distance map according to the inter-vehicle distance immediately after being switched to OFF and the host vehicle speed.

  According to the ACC device 1, it is possible to prevent a change in the target inter-vehicle distance contrary to the driver's intention by prohibiting the change in the target inter-vehicle distance when the host vehicle speed is equal to or lower than the threshold.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the present embodiment, the present invention is applied to an ACC device that performs preceding vehicle follow-up control and constant speed control, but may be applied to a device that performs only preceding vehicle follow-up control (inter-vehicle distance control).

  In this embodiment, the millimeter wave radar is applied to detect the preceding vehicle, but other radars such as a laser radar or other detection means such as a stereo camera may be applied.

  In this embodiment, a plurality of ECUs are provided, and the engine control and the brake control are performed using the engine control ECU and the brake control ECU. However, the engine control and the brake control may be directly performed by the ACC ECU. .

  Further, in the present embodiment, the change of the target inter-vehicle distance map is prohibited when the host vehicle speed is equal to or lower than the threshold. However, a new target based on the originally set target inter-vehicle distance map and the inter-vehicle distance immediately after the end of the operation is used. It is good also as a structure which suppresses the change of target inter-vehicle distance, such as changing to the target inter-vehicle distance map in the middle with the inter-vehicle distance map.

  In the present embodiment, a target inter-vehicle distance map corresponding to the own vehicle speed and the inter-vehicle distance is selected from a plurality of target inter-vehicle distance maps prepared in advance, and a target corresponding to the own vehicle speed is selected from the selected target inter-vehicle distance map. Although the configuration is such that the inter-vehicle distance is extracted, the target inter-vehicle distance value itself may be set and changed instead of using the target inter-vehicle distance map.

It is a block diagram of the ACC apparatus which concerns on this Embodiment. It is an example of the target inter-vehicle distance map used with ACC ECU of FIG. It is a flowchart which shows the flow of the target inter-vehicle distance map change permission control in ACC ECU of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... ACC apparatus, 10 ... Millimeter wave radar, 11 ... Vehicle speed sensor, 12 ... Accel pedal sensor, 13 ... Brake pedal sensor, 14 ... ACC switch, 20 ... Engine control ECU, 21 ... Brake control ECU, 30 ... ACC ECU

Claims (1)

An inter-vehicle distance control device that controls a vehicle so that the inter-vehicle distance from a preceding vehicle becomes a target inter-vehicle distance,
At least one operation detecting means of an acceleration operation detecting means for detecting an acceleration operation of the driver and a deceleration operation detecting means for detecting a deceleration operation of the driver;
Vehicle speed detection means;
A target inter-vehicle distance changing unit that changes the target inter-vehicle distance in a plurality of stages based on the inter-vehicle distance at the end of the acceleration operation or the deceleration operation of the driver detected by the operation detecting unit;
An inter-vehicle distance control device that suppresses a change in a target inter-vehicle distance by the target inter-vehicle distance setting unit when a vehicle speed detected by the vehicle speed detection unit is equal to or less than a threshold value.

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