JP7254421B2 - Tracking control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a follow-up travel control device that performs control to follow a preceding vehicle while maintaining a predetermined inter-vehicle distance with respect to a preceding vehicle to be followed in front of the own vehicle.

Conventionally, for example, as described in Patent Document 1, the distance to a target in front of the vehicle detected by a ranging sensor such as a camera or laser radar, the vehicle speed of the vehicle detected by a vehicle speed sensor, and the corresponding Detects whether the target is a preceding vehicle traveling in the same lane as the vehicle based on the relative speed of the target, etc. There is a follow-up travel control device that performs control to follow and travel a preceding vehicle while maintaining a predetermined inter-vehicle distance.

JP 2011-194900 A (paragraphs 0023 to 0024 and FIG. 1)

However, in the control as disclosed in Patent Document 1, the following problems may occur due to the performance limit of the distance measuring sensor. That is, as shown in FIG. 3, when a vehicle 51 traveling straight on the road is about to enter a curved road 52, an image taken by a camera, for example, a distance measuring sensor, indicates the entrance of the curve in front of the vehicle 51. The installed guardrail 52a may be regarded as a moving target as shown in the hatched area of the square in the figure, and may be misidentified as the preceding vehicle to be followed, and in addition, it is the target to be followed. Since the moving speed of the guardrail 52a misidentified as being is very slow, when the distance to the own vehicle 51 is reduced to a predetermined distance, the brake means is automatically operated to rapidly decelerate the own vehicle 51.例文帳に追加

In this way, if the guardrail 52a is determined to be a stationary object that does not move, it will not be misidentified as a tracked object. Although the driver of the own vehicle 51 knows that it is not the object to be followed but the guardrail 52a, the sudden deceleration of the own vehicle 51 unexpectedly against the driver's will makes the driver feel uncomfortable. be.

SUMMARY OF THE INVENTION An object of the present invention is to prevent a vehicle from being suddenly decelerated carelessly against the driver's will.

In order to achieve the above object, a follow-up cruise control system of the present invention performs control to follow a preceding vehicle while maintaining a predetermined inter-vehicle distance with respect to a preceding vehicle to be followed in front of the own vehicle. In the running control device, detection means for detecting whether or not a target in front of the own vehicle is the preceding vehicle traveling in the same lane as the own vehicle; a control means for determining whether or not the preceding vehicle may be set and, if it is determined to be set, for controlling the rotation of the brake means and the engine so that the vehicle follows the target; is within a predetermined temporary selection allowable range, the moving speed of the target is equal to or higher than the predetermined speed, and the target is determined to be a stationary object within a short distance, the target is the preceding vehicle to be followed. , and final selection of the target to be tracked is performed, and even if the distance between the target and the own vehicle is within the predetermined temporary selection permission range, the moving speed of the target is the predetermined speed. If it is determined that the target is not a stationary object within a short distance, it is determined that the target is not the preceding vehicle that is the target to be tracked, but it cannot be determined as the target to be tracked, and provisional selection is performed as the target to be tracked. When the brake means needs to be decelerated while the target detected by the detection means is temporarily selected , the vehicle is decelerated at a deceleration smaller than the deceleration during follow-up travel in the final selection state. It is characterized by controlling the braking means as follows.

According to the present invention, in a provisional selection state in which it is not decided whether or not the target in front of the own vehicle detected by the detecting means may be set as the preceding vehicle to be tracked, although the preceding vehicle is not the vehicle to be tracked, When it is necessary to control the deceleration of the brake means by the control means, the brake means is controlled so that the deceleration is smaller than the deceleration during the follow-up running in this selected state. When it becomes necessary to decelerate the braking means, the host vehicle can be decelerated at a deceleration smaller than the deceleration during normal follow-up running in this selected state. Therefore, it is possible to prevent the vehicle from being suddenly decelerated carelessly, thereby eliminating the sense of incongruity given to the driver.

1 is a block diagram of an embodiment of a follow-up cruise control device according to the present invention; FIG. FIG. 2 is an operation explanatory diagram of FIG. 1; FIG. 11 is an operation explanatory diagram of a conventional example;

An embodiment of a follow-up cruise control system according to the present invention will be described in detail with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1, the follow-up cruise control device 1 includes a CCD camera 2 for capturing an image of the front of the vehicle, a vehicle speed sensor 3 for detecting the vehicle speed, an ECU (Electronic Control Unit) 4 configured with a microcomputer, A brake actuator (corresponding to "brake means" in the present invention) 5 that automatically applies brakes under the control of the ECU 4, an engine control unit 6 that performs engine control, a follow-up set switch 7 for starting follow-up travel, and a follow-up release. and a follow-up release switch 8 for operation.

The ECU 4 captures an image captured by the camera 2, and compares the camera image with a matching image pattern of pedestrians, various vehicles, road structures, etc. stored in the internal memory of the ECU 4, for example, to obtain an image by so-called pattern recognition. It has a function as a "detection means" in the present invention for performing recognition processing and detecting a preceding vehicle as a follow target traveling in the same lane as the own vehicle.

At this time, when the ECU 4 processes the image captured by the camera 2 and detects a target in front of the vehicle,
(1) Whether the distance between the detected target and the own vehicle is within a preset provisional selection permission range (for example, within 100 m);
(2) whether the moving speed of the detected target is equal to or higher than a predetermined speed;
(3) whether the detected target is a stationary object within a predetermined short distance;
When it is determined that the distance between the target and the host vehicle is within the provisional selection permission range, the moving speed of the target is equal to or higher than a predetermined speed, and that the target is a stationary object within a short distance. , the target is determined to be the preceding vehicle to be tracked, and final selection of the target to be tracked is performed. If it is determined that the moving speed of the target is not a predetermined speed or higher and that it is not a stationary object within a short distance, the target is determined not to be the preceding vehicle to be tracked, but it cannot be determined as the target to be tracked. and provisional selection is performed. If the distance between the target and the host vehicle is not within the provisional selection allowable range, it is determined that there is no follow target.

When the main selection of the target to be followed is made by the ECU 4 while the follow-up set switch 7 is turned on, the ECU 4 determines in advance from the preceding vehicle selected as the target to be followed according to the traveling speed. The brake actuator 5 and the engine control unit 6 are controlled so that the vehicle follows the preceding vehicle at the same speed while maintaining a predetermined inter-vehicle distance. Further, when the follow-up canceling switch 8 is turned on during follow-up running, the ECU 4 cancels the control to follow the preceding vehicle.

At this time, by operating the set switch 7, the brake actuator 5 and the engine control unit 6 are controlled so that the vehicle travels at a constant speed, for example, with the expressway speed limit of 100 km/h as the set speed. The brake actuator 5 and the engine control unit 6 are controlled so that the vehicle follows the preceding vehicle within the set speed range when the preceding vehicle is detected.

Furthermore, when a new preceding vehicle traveling in the same lane as the host vehicle is recognized, such as when a preceding vehicle traveling in an adjacent lane changes lanes, the preceding vehicle is officially selected as a target to be followed, and control is performed to follow the vehicle. For example, while traveling at a constant speed of 100 km/h, the preceding vehicle that has newly changed lanes in this way is officially selected as a target to be followed, and the speed of the newly selected preceding vehicle is 80 km/h. If h is slower than the own vehicle, the ECU 4 performs normal braking control of the brake actuator 5 so as to decelerate at a predetermined deceleration set in advance, and then the engine control unit so as to follow the preceding vehicle at the same speed. 6 is controlled.

On the other hand, even if a target is detected in front of the vehicle, in the state where the target is provisionally selected as the target to be followed, even when the brake actuator 5 needs to be decelerated, the actual selection The brake actuator 5 is under slow braking control so that the deceleration is less than the predetermined deceleration at . That is, unlike the deceleration control in the case of this selection, sudden braking due to large deceleration does not occur. Such a control function of the ECU 4 corresponds to the "control means" in the present invention.

When the ECU 4 detects that a pedestrian exists in front of the vehicle, the relative distance between the vehicle and the pedestrian in the direction of travel is determined based on the vehicle speed detected by the vehicle speed sensor 3 and the image captured by the camera 2. The derived distance between the vehicle and the pedestrian reaches the limit at which a collision can be avoided when the vehicle is braked at the required deceleration (applied the brakes). When this occurs, the ECU 4 can control the brake actuator 5 to activate the automatic brake.

Next, the control operation of the ECU 4 will be described with reference to the flow chart of FIG.

As shown in FIG. 2, the ECU 4 processes the image captured by the camera 2 to determine whether or not a target is detected in front of the vehicle (step S1). is not detected, the engine control unit 6 is controlled so as to move to step S2 and to run at a predetermined set speed (step S2).

On the other hand, when the determination result in step S1 is YES, that is, when a target is detected, the target acceleration of the own vehicle is derived so as to follow the detected target (step S3), and the inter-vehicle distance between the own vehicle and the target is calculated. Based on the above, it is determined whether or not it is necessary to decelerate the own vehicle (step S4). If the determination result is NO, the process proceeds to step S2. , that is, whether the target is officially selected as the target to be tracked (step S5).

If the determination result in step S5 is YES and the final selection is made, the process proceeds to step S6, and when brake control is required during following, normal brake control is performed by a predetermined deceleration (step S6). If the determination result in step S5 is NO and the determination result indicates that the temporary selection is made instead of the actual selection, the process proceeds to step S7. Gentle brake control is performed with a deceleration smaller than the deceleration in the control (step S7). After the processing of steps S2, S6 and S7, the process returns to step S1.

It should be noted that normal brake control is executed when the state in which the temporary selection of gentle brake control is performed by the processing of steps S5 and S7 is changed to the final selection by the determination of step S5 in FIG.

Therefore, according to the above-described embodiment, whether or not the target in front of the own vehicle detected based on the photographed image of the camera 2 may be set as the preceding vehicle to be followed, although it is not the preceding vehicle to be followed. When the ECU 4 needs to decelerate the brake actuator 5 in an undetermined provisional selection state, the brake actuator 5 is controlled to decelerate at a rate smaller than the deceleration in the final selection state. If brake control is required in the provisionally selected state in which it is not possible to determine the target to be tracked, such as misidentifying a guardrail installed on a curved road, slow braking control can be performed at a lower deceleration than in the case of this selection. It is possible to prevent the vehicle from suddenly decelerating unexpectedly against the driver's will, as in the conventional art, and to eliminate the sense of incongruity given to the driver.

In addition, when the state in which the provisionally selected gentle brake control is performed is changed to the state in which the final selection is performed, the normal brake control is executed, so that the driver can drive comfortably without any sense of incongruity. .

The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the CCD camera 2 is used as the detection means, but the present invention can also be applied to a case where a laser radar or a millimeter wave radar is used instead of the camera.

Further, in the above-described embodiment, the conditions for determining whether provisional selection or final selection are made are whether the distance between the host vehicle and the target is within the provisional selection allowable range, whether the moving speed of the target is within a predetermined speed, whether the target is Although whether or not an object is a near-distance stationary object has been exemplified, the condition for determining whether it is a temporary selection or a final selection is not limited to this.

Further, the present invention can be applied to a device that performs control to follow a preceding vehicle while maintaining a predetermined inter-vehicle distance with respect to a preceding vehicle to be followed in front of the own vehicle.

1 ... Follow-up travel control avoidance device 2 ... CCD camera (detection means)
4 ... ECU (control means)

Claims (1)

A follow-up cruise control device that performs control to follow a preceding vehicle while maintaining a predetermined inter-vehicle distance with respect to a preceding vehicle to be followed in front of the own vehicle,
detection means for detecting whether or not a target in front of the own vehicle is the preceding vehicle traveling in the same lane as the own vehicle;
a control means for determining whether or not the target detected by the detection means may be set as the preceding vehicle to be followed, and for controlling rotation of the engine and braking means so that the vehicle follows the target if it is determined to be set. ,
The control means is
When it is determined that the distance between the target and the host vehicle is within a predetermined temporary selection permission range, the moving speed of the target is equal to or higher than the predetermined speed, and the target is a stationary object within a short distance, Determining that the target can be set as the preceding vehicle that is the target to be tracked, and performing final selection of the target to be tracked,
Even if the distance between the target and the own vehicle is within the predetermined temporary selection permission range, if the moving speed of the target is not equal to or higher than the predetermined speed and it is determined that the target is not a stationary object within a short distance, The target is not the preceding vehicle to be tracked, but it is determined that it cannot be determined as the target to be tracked, and provisionally selected as the target to be tracked,
When the brake means needs to be decelerated while the target detected by the detection means is temporarily selected , deceleration is performed at a deceleration smaller than the deceleration during following travel in the final selection state. A follow-up cruise control device, characterized in that it controls the brake means so as to

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