JP2018073365A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of suppressing unnecessary vehicle control for a ghost target.SOLUTION: In a vehicle control device 100, a detection unit 10 detects a target by reflected radio waves of radio waves transmitted to surroundings of a vehicle. A vehicle control unit 20 performs vehicle control based upon information on the target detected by the detection unit 10. A prohibition unit 22 prohibits vehicle control by the vehicle control unit 20 when a reflection area of the target is smaller than a reflection area threshold that is set larger as the target speed increases.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle control device that performs vehicle control (driving support) for avoiding a collision between a host vehicle and a target.

  2. Description of the Related Art A technique for detecting a target around a host vehicle using radio waves and performing vehicle control for avoiding a collision between the host vehicle and the target based on information on the detected target is known (for example, a patent) Reference 1).

JP 2014-191595 A

  With the above technique, there is a possibility that unnecessary vehicle control may be performed on a target that does not actually exist (hereinafter referred to as a ghost target) detected due to reflection of radio waves by a guard rail or the like.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which can suppress the unnecessary vehicle control with respect to a ghost target.

  In order to solve the above-described problem, a vehicle control device according to an aspect of the present invention includes a detection unit that detects a target by reflected radio waves transmitted to the periphery of the host vehicle, and the object detected by the detection unit. A vehicle control unit that performs vehicle control based on information about the target, and a vehicle by the vehicle control unit when the reflection area of the target is smaller than a reflection area threshold that is set larger as the speed of the target is higher A prohibiting unit that prohibits control.

  According to this aspect, since the reflection area of a ghost target at a certain speed is smaller than the reflection area of an actual target assumed to move at the speed, the reflection area of the target detected by the detection unit is When the reflection area threshold value is set larger as the speed is higher, the target is likely to be a ghost target. By prohibiting vehicle control in such a case, unnecessary vehicle control for a ghost target can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the unnecessary vehicle control with respect to a ghost target can be suppressed.

It is a block diagram of the vehicle control device concerning one embodiment. It is a figure which shows the position of the target which is the own vehicle and another vehicle. It is a figure which shows the map of the speed of the target which concerns on one Embodiment, and the reflective area of a target. It is a figure which shows the position of the own vehicle and a ghost target. FIG. 5A is a diagram showing a left alert display according to an embodiment, FIG. 5B is a diagram showing a right alert display, and FIG. It is a figure which shows the display of alerting. It is a figure which shows the display of the warning which concerns on one Embodiment. It is a flowchart which shows the process of the prohibition part of FIG. It is a figure which shows the map of the speed of the target which concerns on a modification, and the reflective area of a target.

  FIG. 1 is a block diagram of a vehicle control apparatus 100 according to an embodiment. A vehicle control device 100 shown in FIG. 1 is a device that is mounted on a vehicle and performs vehicle control for avoiding collisions with targets such as pedestrians, bicycles, and other vehicles. The vehicle control in the present embodiment includes performing intervention control such as braking and steering directly in the host vehicle, and alerting or warning the driver of the host vehicle. Also called support.

  As shown in FIG. 1, the vehicle control device 100 includes an external sensor (detection unit) 10, an internal sensor 12, an ECU (Electronic Control Unit) 14, an HMI (Human Machine Interface) 16, and a brake actuator 18. Prepare.

  The external sensor 10 detects a target such as a moving object based on a reflected radio wave transmitted to the periphery of the host vehicle. The external sensor 10 is, for example, a laser radar or a millimeter wave radar. When the external sensor 10 is a millimeter wave radar, the external sensor 10 detects a target located in front of or in front of the host vehicle by transmitting and receiving a frequency-modulated millimeter wave radar wave, and based on the detection result, Information about the target such as the position and speed of the target is generated. The external sensor 10 outputs information regarding the detected target to the ECU 14.

  The internal sensor 12 is a sensor that detects the traveling state of the host vehicle. The internal sensor 12 includes, for example, a yaw rate sensor that detects the yaw rate of the vehicle, a steering angle sensor that detects the steering angle of the steering, and a vehicle speed sensor that detects the vehicle speed of the vehicle. The inner world sensor 12 outputs vehicle information indicating the detected traveling state of the host vehicle to the ECU 14.

  The ECU 14 includes a vehicle control unit 20 and a prohibition unit 22. The ECU 14 includes a computer, and various functions of the ECU 14 can be configured by a circuit block, a memory, and other LSIs in hardware, and are realized by a program loaded in the memory in software. Accordingly, it is understood by those skilled in the art that various functions of the ECU 14 can be realized in various forms only by hardware, only software, or a combination thereof, and is not limited to any one.

  The vehicle control unit 20 performs vehicle control based on information related to the target detected by the external sensor 10 and vehicle information detected by the internal sensor 12. A specific method for controlling the vehicle is not particularly limited, and various known techniques can be employed. An example will be described below.

  FIG. 2 is a diagram illustrating the positions of the host vehicle C1 and the target C2 that is another vehicle. Here, as shown in FIG. 2, it is assumed that the target C2 is traveling in the direction intersecting the traveling direction of the host vehicle C1 at the road intersection.

  The vehicle control unit 20 determines the collision time between the host vehicle C1 and the target C2 based on the information about the target C2 and the vehicle information, that is, the intersection where the host vehicle C1 and the target C2 intersect. The time until each C2 arrives is calculated. As such time, TTC (Time To Collision) or the like can be used.

  The vehicle control unit 20 determines whether or not to perform vehicle control based on TTC or the like. Specifically, the vehicle control unit 20 does not perform vehicle control when there is no possibility of a collision based on TTC or the like, and outputs a warning signal when the probability of a collision is increased, thereby driving the host vehicle. Alert the person. Further, the vehicle control unit 20 outputs a warning signal to warn the driver of the own vehicle when the probability of collision is higher than the case of alerting based on TTC or the like. In addition, based on TTC or the like, the vehicle control unit 20 outputs an intervention control signal and performs intervention control such as braking when the probability of collision is higher than that of a warning. The vehicle control part 20 should just be comprised so that at least any one of alerting, a warning, and intervention control can be performed.

  The prohibition part 22 is based on the information regarding the target detected by the external sensor 10 and the vehicle control part 20 when the reflection area of the target is smaller than the reflection area threshold that is set larger as the speed of the target is higher. Vehicle control by is prohibited. That is, the reflection area threshold changes according to the speed of the target. When the vehicle control is prohibited, the vehicle control unit 20 does not perform the vehicle control. Here, the reflection area means a radar cross section (RCS) based on the distance between the target and the external sensor 10 and the received power of the external sensor 10.

  In other words, the prohibition unit 22 determines that when all of the following four conditions 1 to 4 regarding the target reflection area and target speed are not satisfied, that is, the target reflection area and target speed. Is outside the range R1 to R4 in FIG. 3, vehicle control by the vehicle control unit 20 is prohibited. On the other hand, when any of the conditions 1 to 4 is satisfied, that is, when the reflection area of the target and the speed of the target are within the ranges R1 to R4 in FIG. The vehicle control by the control unit 20 is permitted.

  FIG. 3 is a diagram illustrating a map of a target speed and a target reflection area according to an embodiment. The map includes four ranges R1-R4.

  The range R1 is a region that satisfies the target velocity <speed threshold LOW and the reflection area threshold L1 ≦ the reflection area of the target ≦ the reflection area threshold H1 (condition 1).

  The range R2 is a region that satisfies the speed threshold LOW ≦ the speed of the target <the speed threshold MID and the reflection area threshold L2 ≦ the reflection area of the target ≦ the reflection area threshold H2 (condition 2).

  The range R3 is a region that satisfies speed threshold MID ≦ target speed <speed threshold HIGH, and reflection area threshold L3 ≦ target reflection area ≦ reflection area threshold H3 (condition 3).

  The range R4 is a region that satisfies the speed threshold HIGH ≦ the speed of the target and the reflection area threshold L4 ≦ the reflection area of the target ≦ the reflection area threshold H4 (condition 4).

  The speed threshold MID is higher than the speed threshold LOW. The speed threshold HIGH is higher than the speed threshold MID.

  The reflection area threshold L1 is 0 in the example of FIG. The reflection area threshold L2 is larger than the reflection area threshold L1. The reflection area threshold L3 is larger than the reflection area threshold L2. The reflection area threshold L4 is larger than the reflection area threshold L3. That is, as described above, the reflection area thresholds L1 to L4 are set to be larger as the speed of the target is higher. The reflection area threshold values H1 to H4 are larger than the reflection area threshold values L1 to L4. In the example of FIG. 3, the reflection area threshold values H1 to H4 are equal to each other, but may be different.

  FIG. 4 is a diagram illustrating the positions of the host vehicle C1 and the ghost target G1. As shown in FIG. 4, when the oncoming vehicle C3 exists, the radar wave transmitted from the external sensor 10 of the host vehicle C1 is reflected by the oncoming vehicle C3, and a part of the reflected wave RW1 is generated on the side of the road. The light is reflected by the reflector 50 such as the guardrail and the signboard. The external sensor 10 receives the reflected wave RW1 reflected by the reflecting object 50, thereby detecting a ghost target G1 that does not originally exist in a direction opposite to the traveling direction of the reflected wave RW1 reflected by the reflecting object 50. To do.

  The electric power of the reflected wave RW1 reflected by the reflector 50 is smaller than the electric power of the reflected wave (not shown) that is reflected by the oncoming vehicle C3 and then directly reaches the external sensor 10 without being reflected by the reflector 50. Therefore, the reflection area of the ghost target G1 at a certain speed is smaller than the reflection area of an actual vehicle that is assumed to normally move at the speed. Therefore, a target whose speed is as high as that of the vehicle during normal travel and whose reflection area is smaller than the reflection area of the vehicle, that is, a target that does not satisfy the conditions 1 to 4 can be regarded as a ghost target. The target may be a bicycle or a pedestrian, and in order to properly consider such a target as a ghost target, the reflection area threshold is set for each predetermined range of the target speed as described above. . The optimum values of the speed threshold values LOW, MID, HIGH and the reflection area threshold values L1 to L4 and H1 to H4 may be obtained by experiments or the like so that it can be appropriately determined whether or not the detected target is a ghost target.

  Returning to FIG. 1, the HMI 16 alerts the driver when it receives an alert signal from the ECU 14, and alerts the driver when it receives an alert signal from the ECU 14. The HMI 16 is, for example, an MID (Multi Information Display) provided on the meter panel.

  FIG. 5A is a diagram showing a left alert display according to an embodiment, FIG. 5B is a diagram showing a right alert display, and FIG. It is a figure which shows the display of alerting. As shown in FIGS. 5A to 5C, when there is a target that should alert the driver, the HMI 16 displays a symbol or a schematic diagram of the target in the direction in which the target exists. A warning message is displayed to notify the driver of the presence of the target.

  FIG. 6 is a diagram illustrating a warning display according to an embodiment. As shown in FIG. 6, the HMI 16 displays a sentence “BRAKE!” Prompting the brake operation, and warns the driver that the target is approaching.

  In addition to the MID, the HMI 16 may further include, for example, a HUD (Head Up Display) provided on the windshield, a buzzer, a speaker, a navigation system monitor, and the like. When the HMI 16 includes a buzzer, when receiving a warning signal from the ECU 14, the buzzer outputs a sound for notifying the driver that a target is present, for example, a sound “beepy”. When the warning signal is received from the ECU 14, the buzzer outputs a sound for notifying the driver that the target is approaching, for example, a sound of “buzzy”.

  Returning to FIG. 1, when the brake actuator 18 receives an intervention control signal from the ECU 14, the brake actuator 18 operates the brake.

  Next, the overall operation of the vehicle control device 100 will be described. The vehicle control unit 20 periodically determines whether or not to perform alerting, warning, or intervention control on the driver based on the information on the target and the vehicle information. In parallel with this operation, the prohibition unit 22 operates as follows.

  FIG. 7 is a flowchart showing the processing of the prohibition unit 22 of FIG. The process of FIG. 7 is performed periodically. First, the prohibition unit 22 acquires information about the target from the external sensor 10 (S1). Next, the prohibition unit 22 determines whether any one of the conditions 1 to 4 is satisfied (S2), and if it is satisfied (Y in S2), permits the vehicle control by the vehicle control unit 20 (S3). ), And terminates the current process. On the other hand, when the conditions 1 to 4 are not satisfied (N in S2), the vehicle control by the vehicle control unit 20 is prohibited (S3), and the current process is terminated.

  As described above, according to the present embodiment, when the reflection area of the target is smaller than the reflection area threshold that is set larger as the speed of the target is higher, vehicle control by the vehicle control unit 20 is prohibited. Different types of ghost targets such as pedestrians and vehicles can be appropriately determined to suppress unnecessary vehicle control over the ghost targets.

  The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are within the scope of the present invention.

  For example, in the above embodiment, the prohibition unit 22 determines whether to prohibit the vehicle control by the vehicle control unit 20 based on the four conditions 1 to 4 (ranges R1 to R4). There is no particular limitation. As an example, five conditions 1 to 5 (ranges R1 to R5) will be described.

  FIG. 8 is a diagram showing a map of the speed of the target and the reflection area of the target according to the modification. Differences from FIG. 3 will be described. In FIG. 8, the range R4 is a region that satisfies the speed threshold HIGH1 ≦ the speed of the target <the speed threshold HIGH2, and the reflection area threshold L4 ≦ the reflection area of the target ≦ the reflection area threshold H4 (condition 4). The range R5 is a region that satisfies the speed threshold HIGH2 ≦ the speed of the target and the reflection area threshold L5 ≦ the reflection area of the target ≦ the reflection area threshold H5 (condition 5). The reflection area threshold values L1 to L5 are set to be larger as the speed of the target is higher. In this modified example, conditions can be set more finely, so that the ghost target can be determined more appropriately.

C1 ... own vehicle, C2 ... target, 10 ... external sensor (detection unit), 20 ... vehicle control unit, 22 ... prohibition unit, 100 ... vehicle control device.

Claims (1)

A detection unit that detects a target by reflected radio waves transmitted around the vehicle;
A vehicle control unit that performs vehicle control based on information on the target detected by the detection unit;
When the reflection area of the target is smaller than a reflection area threshold that is set larger as the speed of the target is higher, a prohibition unit that prohibits vehicle control by the vehicle control unit;
A vehicle control device comprising:

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