JP6802123B2 - Alarm sound output device - Google Patents

Description

The present invention relates to an alarm sound output device that outputs an alarm sound according to an index value having a correlation with the possibility of contact between a target and the own vehicle.

One of the conventionally known alarm sound output devices of this type (hereinafter referred to as "conventional device") is a periodic sound (for example, the same) based on the distance L from the own vehicle to a pedestrian (target). A single sound of the same pitch with a length ta is repeated three times with a fixed pause time tb in between, and then an intermittent sound with a final pause time of twice the length of the pause time tb (2, tb)) is emitted as an alarm sound. Occurs as. Further, the conventional device changes the period T of the periodic sound (for example, T = ta + tb + ta + tb + ta + tb + 2 · tb) based on the distance L. Therefore, the driver of the own vehicle can recognize that the distance L has changed by the change in the period T of the periodic sound (see, for example, Patent Document 1).

In the conventional device, the period T of the periodic sound is calculated according to the following equation (1) with respect to the distance L, where A and B are positive constants.
T = 1 / (AB ・ L)… (1)

JP-A-2005-332143 (see paragraphs 0010, 0031 and 0032)

As understood from the above equation (1), the above-mentioned conventional device generates a periodic sound so that the period T becomes smaller as the distance L becomes smaller. When the distance L becomes "0", the period T becomes the minimum value (1 / A). Here, it is assumed that a configuration for outputting continuous sound instead of periodic sound is applied to the above-mentioned conventional device when the distance L becomes smaller than the threshold distance L1th. The continuous sound is a sound in which the alarm sound is continuously output.

Under such an assumption, the period T when the distance L is the threshold distance L1th is “1 / (AB ・ L1th)”. This period T (= 1 / (AB · L1th) is extremely short depending on the values set in the constants A and B and the threshold distance L1th. Therefore, the distance L is a threshold distance from the threshold distance L1th or more. When the value changes to less than L1th, that is, when the alarm sound is switched from the periodic sound to the continuous sound, the driver may recognize that the periodic sound is generated even though the continuous sound is generated. ..

Whether the intermittent sound or the continuous sound is notified as the alarm sound is important for the driver in determining whether or not the driver is likely to come into contact with the target and the own vehicle. Therefore, as described above, when the driver misunderstands that "a periodic sound is generated when a continuous sound is generated", the driver can make contact even though there is a high possibility of contact in reality. It may be judged that the sex is not so high.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide an alarm sound output device that reduces the possibility that the driver mistakenly recognizes that "an intermittent sound is generated when a continuous sound is generated".

The alarm sound output device of the present invention (hereinafter, also referred to as “the device of the present invention”) is
A target information acquisition unit (21A to 21F, 10 and step 605) that acquires target information including the distance between the target and the own vehicle, and
Alarm sound sounding parts (31 and 10) capable of sounding alarm sounds,
A control unit (10, step 640 and step 660) for causing the alarm sound sounding unit to sound the alarm sound is provided.

Further, the control unit
The control unit
The index value (distance L and collision required time TTC), which is calculated based on the target information and indicates a smaller value as the possibility of contact between the target and the own vehicle is higher, is equal to or less than the first threshold value and is said to be the first. When the intermittent sound condition, which is smaller than one threshold and larger than the second threshold, is satisfied (Lct <L ≦ Lsth and Tcth <TTC ≦ Tsth), the alarm sound is started to be sounded, and the warning sound is started to be sounded. When a predetermined output time (Ton) elapses from the time point (time point ts in FIG. 3A) (time point tf1 in FIG. 3A), the sounding of the alarm sound is stopped, and the sounding of the warning sound is stopped. After a predetermined stop time (Toff) has elapsed, the alarm sound sounding unit is made to sound an intermittent sound pattern that starts to sound the alarm sound again.
When the continuous sound condition in which the index value is equal to or less than the second threshold value is satisfied (L ≦ Lct and TTC ≦ Tct), the warning sound sounding unit is made to sound the continuous sound pattern that keeps the warning sound sounding.

Further, the control section, when the intermittent sound conditions are satisfied, the index value is reduced the stop time by a predetermined interval (GDA) as you decrease by a predetermined amount (see FIGS. 4 and 8 ), The larger the absolute value of the speed of the own vehicle, the larger the predetermined amount of the index value required for shortening the stop time by the predetermined interval, and the index value for satisfying the intermittent sound condition becomes larger. The stop time (minimum stop time Toff) at the minimum is set longer than the predetermined interval (see FIGS. 4 and 8).

Therefore, the stop time when the index value for satisfying the intermittent sound condition is the smallest is longer than the predetermined interval. This predetermined interval may be set to a length that allows the driver to reliably recognize that the intermittent sound is shortened in the process in which the index value gradually decreases (the process in which the possibility of contact gradually increases). High quality. Therefore, in the process in which the index value gradually decreases, even if the index value is slightly larger than the second threshold value, an intermittent sound having a stop time that can be clearly recognized as an intermittent sound is notified. When the index value becomes equal to or less than the second threshold value, a continuous sound is notified. As a result, the alarm sound in the continuous sound starts to be output after at least a predetermined interval has elapsed from the time when the output of the alarm sound is stopped in the intermittent sound immediately before the continuous sound is notified. Therefore, it is possible to improve the possibility that the driver can determine that the intermittent sound has been switched to the continuous sound, and the driver can mistakenly recognize that "the intermittent sound is generated when the continuous sound is generated". The sex can be reduced. Furthermore, the interval at which the stop time of the intermittent sound pattern becomes shorter when the absolute value of the speed of the own vehicle is large, and the interval at which the stop time of the intermittent sound becomes shorter when the absolute value of the speed of the own vehicle is small. Can be prevented from being significantly different. Depending on the absolute value of the speed of the own vehicle, it can be difficult for the driver to remember the discomfort that this interval is different.

According to one aspect of the invention
The control unit
The stop time (minimum stop time Toff) when the index value for satisfying the intermittent sound condition is the smallest is set to be equal to or longer than the output time (Ton) (see FIGS. 4 and 8).
It is configured as follows.

As a result, the stop time when the index value for satisfying the intermittent sound condition is the smallest is longer than the output time, so that it is possible to improve the possibility that the driver can determine that the intermittent sound has been switched to the continuous sound. It is possible to reduce the possibility that the driver mistakenly thinks that "intermittent sound is generated when continuous sound is generated".

According to one aspect of the invention
The control unit
When the continuous sound condition is satisfied when the index value becomes equal to or less than the second threshold value during the sounding of the intermittent sound pattern of the stop time when the index value for satisfying the intermittent sound condition is the smallest, the above-mentioned When the stop time of the intermittent sound pattern being sounded elapses after the continuous sound condition is satisfied, the continuous sound pattern starts to be sounded by the alarm sound sounding unit (second stage tk in FIG. 10). See td.).

This makes it possible to reliably determine that the driver has switched from the intermittent sound to the continuous sound, and at the same time, notify the driver of the continuous sound as soon as possible.

According to one aspect of the invention
The control unit
When the continuous sound condition is satisfied when the index value becomes equal to or less than the second threshold value during the sounding of the intermittent sound pattern of the stop time when the index value for satisfying the intermittent sound condition is the smallest, the above-mentioned When the continuous sound condition is satisfied, the continuous sound pattern is started to be sounded by the alarm sound sounding unit (see the third stage te in FIG. 10).

As a result, when the continuous sound condition is satisfied, the continuous sound can be immediately notified to the driver.

According to one aspect of the invention
The control unit
Using the distance (L) between the target and the own vehicle as the index value,
When the distance is equal to or less than the first threshold value and larger than the second threshold value (Lcs <L ≦ Lsth), the intermittent sound condition is satisfied, and the intermittent sound pattern is caused by the alarm sound sounding unit to sound.
When the distance is equal to or less than the second threshold value (L ≦ Lct), the continuous sound condition is satisfied, and the continuous sound pattern is made to sound by the alarm sound sounding unit.
Further, when the intermittent sound condition is satisfied, the stop time is shortened by the predetermined interval (GDA) as the distance becomes smaller (see FIGS. 4 and 8), and the intermittent sound condition is set. The stop time (minimum stop time Toff) when the distance to be established is the shortest is set longer than the predetermined interval (see FIGS. 4 and 8).

As a result, since the distance between the target and the own vehicle is used as an index value having a correlation with the contact possibility, this distance has a more accurate correlation with the contact possibility. Since the intermittent sound pattern and the continuous sound pattern are generated based on such a distance, it is possible to notify the driver of more accurate contact possibility.

In the above description, in order to help the understanding of the invention, the name and / or the code used in the embodiment is added in parentheses to the structure of the invention corresponding to the embodiment described later. However, each component of the invention is not limited to the embodiments defined by the names and / or symbols. Other objects, other features and accompanying advantages of the invention will be readily understood from the description of embodiments of the invention described with reference to the drawings below.

FIG. 1 is a schematic system configuration diagram of an alarm sound output device (first device) according to the first embodiment of the present invention. FIG. 2 is a bird's-eye view of the own vehicle for explaining the mounting position of the ultrasonic sensor shown in FIG. FIG. 3A is a timing chart of the output and stop of the alarm sound in the intermittent sound. FIG. 3B is a timing chart of the output and stop of the alarm sound in the continuous sound. FIG. 4 is an explanatory diagram of alarm sound information. FIG. 5 is a timing chart showing the relationship between the distance between the target and the own vehicle and the output and stop timing of the alarm sound. FIG. 6 is a flowchart showing a routine executed by the CPU of the alarm sound output ECU shown in FIG. FIG. 7 is a flowchart showing a routine executed by the CPU of the alarm sound output ECU of the modified example of the first device. FIG. 8 is an explanatory diagram of alarm sound information of a modified example of the first device. FIG. 9 shows that when the alarm sound output device (second device) according to the second embodiment of the present invention acquires a distance satisfying the intermittent sound condition during the notification of the intermittent sound, the intermittent sound being notified is changed. It is explanatory drawing of the process. FIG. 10 is an explanatory diagram of a process of changing the intermittent sound being notified to a continuous sound when the second device acquires a distance satisfying the continuous sound condition during the notification of the intermittent sound.

Hereinafter, the alarm sound output device according to each embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic system configuration diagram of an alarm sound output device (hereinafter, may be referred to as “first device”) according to the first embodiment of the present invention. When it is necessary to distinguish the vehicle equipped with the first device from other vehicles, it is referred to as "own vehicle SV". The first device uses the "distance L between the target and the own vehicle SV" as an index value (contact index value) having a correlation with the contact possibility between the target and the own vehicle SV, and sets the distance L to the said distance L. An alarm sound is output accordingly.

The first device includes an alarm sound output ECU 10. The ECU is an abbreviation for "Electronic Control Unit" and includes a microcomputer as a main part. The microcomputer includes a CPU 11, a ROM 12, and a storage device such as a RAM 13. The CPU 11 realizes various functions by executing instructions (programs, routines) stored in the ROM 12.

The first device further includes ultrasonic sensors 21A to 21F, a vehicle state sensor 22, and a speaker 31 (alarm sound sounding unit). The alarm sound output ECU 10 is connected to the ultrasonic sensors 21A to 21F, the vehicle state sensor 22, and the speaker 31. When it is not necessary to distinguish the ultrasonic sensors 21A to 21F individually, the term "ultrasonic sensor 21" is used.

The ultrasonic sensor 21 uses ultrasonic waves to detect the position of the target and the relative speed of the target with respect to the own vehicle SV. Specifically, the ultrasonic sensor 21 emits (transmits) ultrasonic waves and receives ultrasonic waves (reflected waves) reflected by a three-dimensional object (target) existing within the radiation range of the ultrasonic waves. Then, the ultrasonic sensor 21 detects "a target point which is a point where the ultrasonic wave is reflected in the target" based on the ultrasonic wave reflected from the target. Then, when the target point is present, the ultrasonic sensor 21 calculates the distance L from the own vehicle SV to the target point based on the time from the transmission to the reception of the ultrasonic wave, and the reflected ultrasonic wave. The direction of the target point with respect to the own vehicle SV is calculated based on the direction. The position of the target point with respect to the own vehicle SV is specified by the distance from the own vehicle SV to the target point and the direction of the target with respect to the own vehicle SV.

Further, the ultrasonic sensor 21 calculates the relative velocity of the target point with respect to the own vehicle SV based on the frequency change (Doppler effect) of the reflected wave of the ultrasonic wave. Then, the ultrasonic sensor 21 transmits the target point information to the alarm sound output ECU 10.

The target point information includes presence / absence information indicating the presence / absence of the target point. Further, the target point information includes the position information of the target point (distance L from the own vehicle SV to the target point and the direction of the target point with respect to the own vehicle SV) and the target when the target point exists. Includes relative velocity of points.

As shown in FIG. 2, six ultrasonic sensors 21A to 21F are attached to the own vehicle SV. Specifically, the ultrasonic sensor 21A is attached to the center of the front bumper FB of the own vehicle SV in the vehicle width direction. The ultrasonic sensor 21B is attached to the left end of the front bumper FB of the own vehicle SV. The ultrasonic sensor 21C is attached to the right end of the front bumper FB of the own vehicle SV. The ultrasonic sensor 21D is attached to the center of the rear bumper RB of the own vehicle SV in the vehicle width direction. The ultrasonic sensor 21E is attached to the left end of the rear bumper RB of the own vehicle SV. The ultrasonic sensor 21F is attached to the right end of the rear bumper RB of the own vehicle SV.

The detection range of the target points of these ultrasonic sensors 21A to 21F is a predetermined angle range and a predetermined distance range. By combining the detection ranges of these ultrasonic sensors 21A to 21F, it is possible to detect targets all around the own vehicle SV. The alarm sound output ECU 10 detects targets existing all around the own vehicle SV based on the target point information from the ultrasonic sensors 21A to 21F. For example, in FIG. 2, the alarm sound output ECU 10 detects a target at a distance L toward the front of the own vehicle SV.

The vehicle state sensor 22 shown in FIG. 1 is a sensor that acquires vehicle state information regarding the running state of the own vehicle SV. The vehicle state sensor 22 is a vehicle speed sensor that detects the speed (that is, vehicle speed) of the own vehicle SV, an acceleration sensor that detects the horizontal front-rear and left-right (lateral) acceleration of the own vehicle SV, and the yaw rate of the own vehicle SV. It includes a yaw rate sensor that detects the steering wheel, a steering angle sensor that detects the steering angle of the steering wheel, and the like. The vehicle condition sensor 22 outputs vehicle condition information to the alarm sound output ECU 10 every time a predetermined time elapses.

The speaker 31 is arranged in the own vehicle SV, receives a command from the alarm sound output ECU 10, and outputs an alarm sound.

(Outline of operation)
Next, the outline of the operation of the first device will be described. The first device selects the target point having the smallest distance L from the own vehicle SV among the target points detected by the ultrasonic sensor 21. The distance L between the selected target point and the own vehicle is referred to as "minimum distance Lmin". The first device notifies the intermittent sound shown in FIG. 3A when the minimum distance Lmin satisfies the following intermittent sound condition, and notifies the continuous sound shown in FIG. 3B when the minimum distance Lmin satisfies the following continuous sound condition. To do.

Intermittent sound condition: The minimum distance Lmin is larger than the continuous sound start distance Lct and the output start distance Lsth or less. Continuous sound condition: The minimum distance Lmin is the continuous sound start distance Lct or less.

The continuous sound start distance Lct is set to a value smaller than the output start distance Lsth. Therefore, the continuous sound condition is satisfied when the minimum distance Lmin is shorter than the intermittent sound condition. The smaller the distance L, the higher the possibility of contact. Therefore, the continuous sound condition is satisfied when the contact possibility is higher than that of the intermittent sound condition.

First, the intermittent sound will be described with reference to FIG. 3A.
As shown in FIG. 3A, when the intermittent sound condition is satisfied, the first device starts to output (pronounce) an alarm sound (sound having a constant pitch) from the speaker 31 at the output start time ts. The first device stops the output of the alarm sound at the time when a predetermined output time Ton (Times) elapses from the output start time ts (output stop time tf1). The first device stops the output of the alarm sound from the output stop time tf1 to the time when the stop time Toff elapses from the output stop time tf1 (stop time elapse time tf2). The period from the output start time ts to the stop time elapse time tf2 is one cycle of the intermittent sound, and this period may be referred to as an “intermittent sound notification period”. The first device starts the sounding of the alarm sound again at tf2 when the stop time elapses. Therefore, the stop time elapsed time point tf2 is also the output start time point ts of the new cycle. As will be described in detail later, the first device sets the stop time Toff corresponding to the minimum distance Lmin based on the alarm sound information 40 shown in FIG.

Next, the continuous sound will be described with reference to FIG. 3B.
As shown in FIG. 3B, when the continuous sound condition is satisfied, the first device emits an alarm sound (a sound having the same pitch as the alarm sound of the intermittent sound being sounded) at the output start time ts. Start to output (pronounce) from. The first device continues to output (pronounce) an alarm sound from the speaker 31 from the output start time ts to the time when a predetermined output time Ton (Tcms) elapses from the output start time ts (output stop time tf). The period from the output start time ts to the output stop time tf is one cycle of continuous sound, and this period may be referred to as a "continuous sound notification period". The first device continues the sounding of the alarm sound without stopping the sounding of the alarm sound at the output stop time tf. Therefore, the output stop time tf is also the output start time ts of a new cycle.

The continuous sound notification period is a period during which the alarm sound is continuously output for a period (Tcms) longer than the output time Ton (Times) of the alarm sound in the intermittent sound notification period. In the continuous sound, the stop time Toff is set to "0 ms". On the other hand, in the intermittent sound notification period, the alarm sound output "corresponds to the minimum distance Lmin" after the alarm sound is output for a period shorter than the alarm sound output time Ton (Tcms) in the continuous sound notification period (Times). It is a period to stop by "Stop time Toff". Therefore, when the intermittent sound is continuously notified, the alarm sound is output intermittently.

The first device sets the output time Ton and the stop time Tof corresponding to the minimum distance Lmin with reference to the alarm sound information 40 shown in FIG. 4, regardless of whether the intermittent sound or the continuous sound is notified. , The alarm sound is output according to the set output time Ton, and the output of the alarm sound is stopped according to the set stop time Tof.

In the alarm sound information 40, the relationship between the distance L between the target and the own vehicle SV and the output time Ton and the stop time Toff corresponding to the distance L is defined. The alarm sound information 40 is stored in advance in the ROM 12 in a look-up table (map) format.

In the alarm sound information 40, the above-mentioned output start distance Lsth is set to "Lscm", and the above-mentioned continuous sound start distance Lcth is set to "Lccm (<Lscm)". Therefore, when the minimum distance Lmin is larger than "Lccm" and less than or equal to "Lscm", the first apparatus determines that the above-mentioned intermittent sound condition is satisfied and notifies the intermittent sound. On the other hand, when the minimum distance Lmin is "Lccm" or less, the first apparatus determines that the above-mentioned continuous sound condition is satisfied and notifies the continuous sound.

Hereinafter, for the sake of simplicity, it is assumed that only one target point is detected. That is, it is assumed that the distance L is equal to the minimum distance Lmin. Further, the distance L (Lccm <L ≦ Lscm) at which the intermittent sound is notified is called “intermittent sound distance Li”, and the distance L (0 cm ≦ L ≦ Lccm) at which the continuous sound is notified is called. It is called "continuous sound distance Lc".

In the alarm sound information 40, the output time Ton with respect to the intermittent sound distance Li is defined as a constant value (Times) regardless of the distance L. In the alarm sound information 40, the output time Ton with respect to the continuous sound distance Lc is defined as "a constant value (Tcms) larger than the output time Ton of the intermittent sound distance Li" regardless of the distance L.

Further, in the alarm sound information 40, the stop time Toff with respect to the intermittent sound distance Li is defined so that the stop time Toff decreases as the distance L decreases. More specifically, the stop time Toff at the intermittent sound distance Li is defined so that each time the distance L decreases by a predetermined length (Ldcm) from the output start distance Lsth, the stop time Toff gradually decreases by a predetermined value (Tgms). There is. Hereinafter, this "stepwise reduction amount (Tgms) of the stop time Toff with respect to a predetermined length (Ldcm) of the distance L" is referred to as a "stepwise reduction amount GDA". On the other hand, in the alarm sound information 40, the stop time Toff of the continuous sound distance Lc is defined as a constant value (0 ms) regardless of the distance L.

As shown in FIG. 4, the minimum stop time Toff that can be set in the intermittent sound distance Li (that is, the distance L is larger than the continuous sound start distance Lcts (Lccm) and has a predetermined length at the continuous sound start distance Lcts (Lccm)). The stop time (Toff) when it is equal to or less than the value (Lc + Ld) to which the (Ldcm) is added is set to “Tims”. This "Tims" is set to "90ms". In the process in which the distance L gradually decreases, if the distance L is slightly larger than the continuous sound start distance Lct, the stop time is stopped by the stop time Tof so that the alarm sound can be clearly recognized as an intermittent sound. When the distance L becomes the continuous sound start distance Lct or less, the continuous sound is notified. As a result, the alarm sound in the continuous sound starts to be output after at least the stop time Toff (Times) has elapsed from the time when the output of the alarm sound is stopped in the intermittent sound immediately before the continuous sound is notified. Hereinafter, the minimum stop time Toff (Times) in the intermittent sound is referred to as "minimum stop time Toff".

This minimum stop time Toff (Tims) is set longer than the step reduction amount GDA (Tgms). This "Tgms" is set to "30 ms". Therefore, the minimum stop time Toff (Tims) is set to the same value as three times the step reduction amount GDA (Tmgms).

The step reduction amount GDA is set to a length that allows the driver to reliably recognize that the stop time Toff in the current intermittent sound is shorter than the stop time Toff in the previous intermittent sound. In other words, the length of the step reduction amount GDA is set to a length that allows the driver to recognize that the output of the alarm sound is stopped if the output of the alarm sound is stopped by the length of the step reduction amount GDA. Has been done. Further, in this example, since the minimum stop time Toff (Tims) is set to a value equal to or greater than the step reduction amount GDA (Tmgms), the driver can reliably determine that the intermittent sound has been switched to the continuous sound. Can be done.

Further, in the alarm sound information 40 shown in FIG. 4, the minimum stop time Toff (Tims) is set to the same value as the output time Ton (Tims) at the intermittent sound distance Li. Here, the output time Ton is set to a length that allows the driver to reliably recognize that an alarm sound is being output. Therefore, if the alarm sound is output for this output time Ton and the output of the alarm sound is stopped for the minimum stop time Tof equal to the output time Ton, the driver can more reliably recognize that the alarm sound is an intermittent sound. .. Therefore, the driver can reliably determine that the intermittent sound has been switched to the continuous sound, and the driver erroneously recognizes that "the intermittent sound is generated even though the continuous sound is generated". The possibility can be reduced.

Therefore, if the minimum stop time Tof is set to a value equal to or greater than at least one (preferably both) of the step reduction amount GDA and the output time Ton in the intermittent sound control, the intermittent sound is switched to the continuous sound. Can be improved in the possibility that the driver can discriminate.

Next, the details of the operation of the first device will be described with reference to FIG.
In FIG. 5, it is assumed that the following assumptions are established.
The minimum distance Lmin at time point t1 is "Lscm".
The minimum distance Lmin at time point t3 is "L3 cm".
The minimum distance Lmin at time point t6 is "L6 cm".
The minimum distance Lmin at time point t8 is "L8 cm".
-"Ls>L3>L6>Lc>L8" is established.

At the time point t1, the minimum distance Lmin (Lscm) becomes equal to or less than the output start distance Lsth (Lscm), and the intermittent sound condition is satisfied. Therefore, the first apparatus starts the notification of the intermittent sound. More specifically, the first apparatus sets the output time Ton (Tims) and the stop time Toff (To1ms) corresponding to the minimum distance Lmin (Lscm) based on the alarm sound information 40. Then, the first device starts to output the alarm sound from the speaker 31 at the time point t1.

The first device stops the output of the alarm sound at the time t2 when the output time Ton (Times) elapses from the time t1 when the alarm sound is started to be output. Then, the first device continues to stop the alarm output from the time point t2 to the "time point t3 when the stop time Toff (To1 ms) elapses". The time point t1 to the time point t3 is one cycle of the intermittent sound, which is the intermittent sound notification period.

Even if the first apparatus newly detects a target with a distance L smaller than the minimum distance Lmin at the time t1 during the intermittent sound notification period from the time point t1 to the time point t3, this newly detected target is detected. The output and stop of the alarm sound are controlled according to the output time Ton (Times) and the stop time Toff (To1 ms) set at the time point t1 without newly outputting the alarm sound corresponding to the distance L.

The first device acquires the minimum distance Lmin (L3 cm) at t3 when the intermittent sound notification period ends. Since this minimum distance Lmin (L3 cm) satisfies the above-mentioned intermittent sound condition, the first device starts the notification of the intermittent sound at the time point t3. More specifically, the first apparatus sets the output time Ton (Times) and the stop time Toff (To2ms) corresponding to the minimum distance Lmin (L3 cm) at the time point t3 based on the alarm sound information 40, and sets the alarm sound. Start output.

The first device starts to output the alarm sound at the time point t3, stops the output of the alarm sound at the time point t4 when the output time Ton (Times) elapses from the time point t3, and the stop time Toff (To2ms) elapses from the time point t4. The alarm output is continuously stopped until t5. Between the time point t5 and the time point 6 shown in FIG. 5, the intermittent sound is notified at the output time Ton and the stop time Toff corresponding to the minimum distance Lmin at the time point t5, but the description is omitted because it is the same as the above description. To do.

Next, when the time point t6 is reached, the first device acquires the minimum distance Lmin (L6 cm). Since this minimum distance Lmin (L6 cm) satisfies the intermittent sound condition, the first apparatus sets the output time Ton (Tims) and the stop time Toff (Times) corresponding to the minimum distance Lmin (L6 cm). Then, the first device starts to output the alarm sound from the speaker 31 at the time point t6.

The first device stops the output of the alarm sound at the time t7 when the output time Ton (Tims) elapses from the time point t6, and stops the output of the alarm from the time point t7 to the time point t8 when the stop time Toff (Times) elapses. To continue.

The first device acquires the minimum distance Lmin (L8 cm) at time point t8. Since this minimum distance Lmin (L8 cm) is equal to or less than the continuous sound start distance Lcth (Lccm), the continuous sound condition described above is satisfied. Therefore, the first device starts the continuous sound notification at the time point t8. More specifically, the first apparatus sets the output time Ton (Tcms) and the stop time Toff (0 ms) corresponding to the minimum distance Lmin (L8 cm) at the time point t8 based on the alarm sound information 40. Then, the first device starts to output the alarm sound at the time point t8. The first apparatus acquires the minimum distance Lmin when the output time Ton (Tcms) elapses from the time point t8. When the minimum distance Lmin satisfies the continuous sound condition, the first device continues to output the alarm sound. On the other hand, if the minimum distance Lmin does not satisfy the continuous sound condition, and if the minimum distance Lmin satisfies the intermittent sound condition, the output time Ton and the stop time Toff are set based on the minimum distance Lmin and the alarm sound information 40. Set and start (continue) the output of the alarm sound.

As described above, in the first device, the minimum stop time Toff of the intermittent sound is set to a value larger than the step reduction amount GDA, and the minimum stop time Toff of the intermittent sound is set to a value equal to or more than the output time Ton. .. In addition, in the first device, when the alarm sound is switched from the intermittent sound to the continuous sound, the alarm sound is not generated (pronounced) for the stop time Toff equal to or longer than the minimum stop time Toff. Therefore, the first device can improve the possibility that the driver can determine that the intermittent sound has been switched to the continuous sound, and the driver "generates the intermittent sound even though the continuous sound is generated". It is possible to reduce the possibility of erroneously recognizing "is".

(Specific operation)
The CPU 11 of the alarm sound output ECU 10 executes the routine shown in the flowchart of FIG. 6 every time a predetermined time elapses. The execution interval of this routine of the CPU 11 follows the operating clock frequency of the CPU 11. Since the operating clock frequency of the CPU 11 is about several hundred MHz, the routine shown in FIG. 6 is executed at a time interval sufficiently shorter than the above-mentioned output time Ton and stop time Toff. The routine shown in FIG. 6 is a routine for outputting an alarm sound.

Therefore, at a predetermined timing, the CPU 11 starts the process from step 600 in FIG. 6, proceeds to step 605, acquires target point information from the ultrasonic sensor 21, and proceeds to step 610. In step 605, the CPU 11 selects the minimum distance Lmin from the distance L included in the acquired target point information.

In step 610, the CPU 11 determines whether or not the value of the notification flag is "1". The value of the notification flag is set to "1" during notification of either the intermittent sound or the continuous sound (see step 625 described later), and when neither the intermittent sound nor the continuous sound is notified, the flag is used. The value is set to "0" (see step 670 below). The CPU 11 is set to "0" in the initial routine executed when the alarm sound output ECU 10 is activated.

When the value of the notification flag is not set to "1", that is, when the value of the notification flag is set to "0", the CPU 11 determines "No" in step 610 and steps 613. Proceed to. In step 613, the CPU 11 determines whether or not the minimum distance Lmin selected in step 605 this time (hereinafter, referred to as “minimum distance Lmin this time”) is larger than the continuous sound start distance Lcts.

If the minimum distance Lmin is larger than the continuous sound start distance Lct this time, the CPU 11 determines “Yes” in step 613 and proceeds to step 615. In step 615, the CPU 11 determines whether or not the minimum distance Lmin this time is smaller than the minimum distance Lmin selected in the previous step 605 (hereinafter, referred to as "previous minimum distance Lmin").

If the minimum distance Lmin this time is smaller than the minimum distance Lmin last time, the CPU 11 determines "Yes" in step 615 and proceeds to step 620. In step 620, the CPU 11 determines whether or not the minimum distance Lmin this time is equal to or less than the output start distance Lsth.

When the minimum distance Lmin is equal to or less than the output start distance Lsth this time, the CPU 11 determines “Yes” in step 620 and proceeds to step 625. If the minimum distance Lmin is equal to or less than the output start distance Lsth this time, the CPU 11 starts to notify either the intermittent sound or the continuous sound. Therefore, in step 625, the CPU 11 sets the value of the notification flag to "1" indicating that either the intermittent sound or the continuous sound is being notified, and proceeds to step 630. In step 630, the CPU 11 initializes the timer TM by setting the value of the timer TM to “0”, and proceeds to step 635.

In step 635, the CPU 11 refers to the alarm sound information 40 and sets the output time Ton and the stop time Tof corresponding to the minimum distance Lmin this time. As described above, when the minimum distance Lmin is equal to or less than the continuous sound start distance Lct this time, the CPU 11 determines that the continuous sound condition is satisfied. In this case, the CPU 11 sets the output time Ton to "Tcms" and the stop time Tof to "0ms". On the other hand, when the minimum distance Lmin is larger than the continuous sound start distance Lct and is equal to or less than the output start distance Lsth, the CPU 11 determines that the intermittent sound condition is satisfied. In this case, the CPU 11 sets the output time Ton to "Tims" and sets the stop time Toff to a time corresponding to the minimum distance Lmin this time.

Next, the CPU 11 proceeds to step 640, starts outputting an alarm sound from the speaker 31, proceeds to step 695, and temporarily ends this routine.

If the value of the notification flag is set to "1" at the time when the CPU 11 executes the process of step 610, the CPU 11 determines "Yes" in the step 610 and proceeds to step 645. In step 645, the CPU 11 sets the value obtained by adding "1" to the value of the timer TM to the value of the new timer TM, and proceeds to step 650.

In step 650, the CPU 11 determines whether or not the value of the timer TM is equal to or greater than the value obtained by adding the output time Ton and the stop time Toff set in step 635 (hereinafter, referred to as “addition value”). Is determined.

If the value of the timer TM is smaller than the added value, the CPU 11 determines "No" in step 650 and proceeds to step 655. In step 655, the CPU 11 determines whether or not the value of the timer TM is equal to or less than the output time Ton.

When the value of the timer TM is equal to or less than the output time Ton, the CPU 11 determines “Yes” in step 655 and proceeds to step 660. In this case, since the output time Ton has not elapsed from the time when the alarm sound is started to be output, the CPU 11 continues to output the alarm sound from the speaker 31 in step 660, proceeds to step 695, and temporarily ends this routine. To do.

On the other hand, when the value of the timer TM is larger than the output time Ton, the CPU 11 determines "No" in step 655 and proceeds to step 665. In this case, since the output time Ton has elapsed from the time when the alarm sound is started to be output, the CPU 11 stops (or continues to stop) the output of the alarm sound in step 665, and proceeds to step 695. Terminate the routine once.

If the value of the timer TM is equal to or greater than the added value at the time when the CPU 11 executes the process of step 650, the CPU 11 determines “Yes” in the step 650 and proceeds to step 670. In this case, since one cycle of the intermittent sound or the continuous sound that has been notified has ended, the CPU 11 sets the value of the notification flag to "0" in step 670, and performs the processing after step 613. move on.

In this way, when the intermittent sound is notified, the CPU 11 starts to output the alarm sound in step 640, and then the value of the timer TM becomes equal to or more than the added value (Ton + Toff), and determines "Yes" in step 650. (That is, until the intermittent sound notification period ends), the processes of steps 655 to 665 are executed. From the time when the alarm sound is started to be output in step 640 until the output time (Ton) elapses, the CPU 11 determines "Yes" in step 655 and continues to output the alarm sound from the speaker 31 in step 660. .. On the other hand, after the output time elapses from the time when the alarm sound is started to be output in step 640 until the intermittent sound notification period ends, the CPU 11 determines "No" in step 655 and in step 655. Continue to stop the output of the alarm sound.

Further, when the continuous sound is notified, the CPU 11 starts to output the alarm sound in step 640, and then the value of the timer TM becomes equal to or more than the added value (Ton + Toff), and is determined as "Yes" in step 650. Until (that is, until the continuous sound notification period ends), "Yes" is repeatedly determined in step 655, and the alarm sound is continuously output from the speaker 31 in step 660.

Here, if the minimum distance Lmin is equal to or less than the continuous sound start distance Lcts at the time when the CPU 11 executes the process of step 613, the CPU 11 determines “No” in step 613 and performs steps 615 and 620. The process proceeds to the process after step 625 without executing.

Further, if the minimum distance Lmin this time is equal to or greater than the previous minimum distance Lmin at the time when the CPU 11 executes the process of step 615, the CPU 11 determines "No" in step 615, proceeds to step 695, and performs this routine. It ends once.

Therefore, when the minimum distance Lmin this time is larger than the continuous sound start distance Lct, and the minimum distance Lmin does not change between the time when this routine was executed last time and the time when this routine is executed this time, and the minimum distance Lmin is large. If any of the cases is satisfied, the first apparatus does not execute the processes after step 620. As a result, since the output time Ton and the stop time Toff of the intermittent sound for the minimum distance Lmin this time are not set, the notification of the intermittent sound for the minimum distance Lmin this time is not started. When the own vehicle SV is stopped with respect to the target having the minimum distance L, or when the own vehicle SV is far from the target, the intermittent sound is not notified, so that the driver is annoyed by the intermittent sound. You can reduce the possibility of feeling.

As described above, when the minimum distance Lmin this time is equal to or less than the continuous sound start distance Lct, the process of step 615 is not executed. Therefore, when the minimum distance Lmin this time is the continuous sound start distance Lct or less, the continuous sound notification is started even if the minimum distance Lmin this time is the minimum distance Lmin or more last time.

On the other hand, if the minimum distance Lmin is larger than the output start distance Lsth at the time when the CPU 11 executes the process of step 620, the CPU 11 determines "No" in step 620 and proceeds to step 695 to execute this routine. It ends once.

As can be understood from the above example, the first apparatus sets the minimum stop time Toff that can be set for the intermittent sound to a value equal to or greater than at least one of the step reduction amount GDA and the output time Ton for the intermittent sound. This makes it possible to improve the possibility that the driver can determine that the intermittent sound has been switched to the continuous sound, and the driver mistakenly thinks that the intermittent sound is generated even though the continuous sound is generated. The possibility of recognition can be reduced.

<Modification example of the first device>
A modification of the first device is that the collision time required TTC (TTC Time To Collision), which is the time until each target point collides with or approaches the own vehicle SV, is used as a contact index value instead of the distance L. , It is different from the first device. Hereinafter, this difference will be mainly described. Similar to the distance L, the collision required time TTC indicates that the smaller the value, the higher the possibility of contact between the target including the target point and the own vehicle SV.

The CPU 11 of the modified example of the first device executes the routine shown by the flowchart in FIG. 7 instead of the routine shown by the flowchart in FIG. Among the steps shown in FIG. 7, the steps in which the same processing as the steps shown in FIG. 6 are performed are given the same reference numerals as those given to such steps in FIG. A detailed description of these steps is omitted.

Therefore, at a predetermined timing, the CPU 11 starts the process from step 700 in FIG. 7, proceeds to step 605, acquires target point information, and proceeds to step 705. In step 705, the CPU 11 acquires the vehicle state information from the vehicle state sensor 22 and proceeds to step 710.

In step 710, the CPU 11 estimates the travel prediction course RCR (see FIG. 2) of the own vehicle SV based on the vehicle state information acquired in step 705, and proceeds to step 715. More specifically, the CPU 11 calculates the turning radius of the own vehicle SV based on the vehicle speed and the yaw rate of the own vehicle SV included in the vehicle state information. Then, the CPU 11 bases the center point of the own vehicle SV in the vehicle width direction based on this turning radius (actually, the center point PO on the axles of the left and right front wheels of the own vehicle SV (see FIG. 2)). The travel course that the vehicle is heading for is estimated as the travel prediction route RCR. When yaw rate is generated, the travel prediction course RCR has an arc shape. When no yaw rate has occurred (that is, when the yaw rate is "0"), the CPU 11 takes a straight course along the direction of acceleration detected by the acceleration sensor, and the traveling course (that is, the traveling course in which the own vehicle SV is heading). That is, it is estimated that the travel prediction course RCR). It should be noted that the CPU 11 advances the travel prediction course RCR by a predetermined distance from the current position of the own vehicle SV along the travel path regardless of whether the own vehicle SV is turning or going straight. That is, it is recognized (determined) as a line of finite length).

In step 715, the CPU 11 determines the own vehicle SV from the target points included in the target point information based on the target point information acquired in step 605 and the travel prediction course RCR estimated in step 710. The target point that is estimated to collide with is extracted as an obstacle point. The obstacle point includes a target point that does not collide with the own vehicle SV but is estimated to be extremely close to the own vehicle SV.

The process of step 715 will be described in detail with reference to FIG.
The CPU 11 is located on the left side travel prediction course LEC through which the point PL located on the left side by a certain distance αL from the left end of the vehicle body of the own vehicle SV and further to the right by a certain distance αR from the right end of the vehicle body of the own vehicle SV. The right-hand travel prediction route REC through which the point PR is passed is estimated based on the "travel prediction route RCR of a finite length". The left-side travel prediction course LEC is a course in which the travel prediction course RCR is translated to the left side of the own vehicle SV in the left-right direction by "a value obtained by adding half the vehicle width to the distance αL". The right-side travel prediction route REC is a route in which the travel prediction route RCR is translated to the right side of the own vehicle SV in the left-right direction by "a value obtained by adding half the vehicle width to the distance αR". The distance αL and the distance αR are both values of “0” or more, and may be different from each other or the same. Further, the CPU 11 specifies the region between the left travel prediction route LEC and the right travel prediction route REC as the travel prediction route region ECA (see FIG. 2).

Then, the CPU 11 calculates (estimates) the movement locus of the target point based on the position of the past target point, and based on the calculated movement trajectory of the target point, the movement direction of the target point with respect to the own vehicle SV. Is calculated. Next, the CPU 11 makes a travel prediction based on the travel prediction course area ECA, the relative relationship (relative position and relative speed) between the own vehicle SV and the target point, and the movement direction of the target point with respect to the own vehicle SV. It is predicted that the target point that already exists in the course area ECA and is predicted to intersect the tip area TA of the own vehicle SV and the travel prediction course area ECA will enter in the future and intersect the tip area TA of the own vehicle. The target point is extracted as an obstacle point that may collide with the SV of the own vehicle. Here, the tip region TA of the own vehicle SV is a region represented by a line segment connecting the point PL and the point PR.

The CPU 11 estimates the left-side travel prediction route LEC as the route through which the point PL passes, and the right-side travel prediction route REC as the route through which the point PR passes. Therefore, if the value αL and the value αR are positive values, the CPU 11 also determines that the target point that may pass near the left side surface or the right side surface of the own vehicle SV is “already in the travel prediction course area ECA”. It is determined that it exists and is predicted to intersect the tip region TA of the own vehicle SV "or" it is predicted to enter the travel prediction course region ECA in the future and intersect the tip region TA of the own vehicle SV ". .. Therefore, the CPU 11 also extracts a target point that may pass through the left side or the right side of the own vehicle SV as an obstacle point.

Next, the CPU 11 proceeds to step 720 and determines whether or not the obstacle point has been extracted in step 715. If the obstacle point is not extracted in step 715, the CPU 11 determines "No" in step 720, proceeds to step 795, and temporarily ends this routine.

If the obstacle point is extracted in step 715, the CPU 11 determines “Yes” in step 720 and proceeds to step 725. In step 725, the CPU 11 calculates the collision time TTC of the obstacle point by dividing the distance between the own vehicle SV and the obstacle point by the relative speed of the obstacle point with respect to the own vehicle SV. In step 725, the CPU 11 selects the minimum collision required time TTC (hereinafter, referred to as “minimum TTC”) among the calculated collision required time TTC.

The collision time required TTC is any of the following time T1 and time T2.
-Time until the time when the obstacle point is predicted to collide with the own vehicle SV T1 (time from the current time to the time when the collision is predicted)
-Time T2 (time from the current time to the closest prediction time) until the time when the obstacle point that may pass by the side of the own vehicle SV comes closest to the own vehicle SV.

In this collision time required TTC, the obstacle point reaches the "tip region TA of the own vehicle SV" when it is assumed that the obstacle point and the own vehicle SV move while maintaining the current relative speed and relative movement direction. It is time to.

The CPU 11 calculates the collision time required TTC in step 725, and then proceeds to the processes after step 610. If the value of the notification flag is "0" at the time when the CPU 11 executes the process of step 610, the CPU 11 determines "No" in step 610 and proceeds to step 730.

In step 730, the CPU 11 has the smallest collision required time TTC (hereinafter, referred to as “this time minimum TTC”) among the collision required time TTC calculated in this step 725, in the previous step 725. It is determined whether or not it is smaller than the minimum collision required time TTC (hereinafter, referred to as "previous minimum TTC") in the calculated collision required time TTC.

If the minimum TTC this time is smaller than the minimum TTC last time, the CPU 11 determines "Yes" in step 730 and proceeds to step 735. In step 735, the CPU 11 determines whether or not the minimum TTC this time is equal to or less than the output start time Tsth (see FIG. 8).

Here, the alarm sound information 80 in this modification will be described with reference to FIG.
In the alarm sound information 80 of this modification, the relationship between the collision required time TTC and the output time Ton and the stop time Toff corresponding to the collision required time TTC is defined. The alarm sound information 80 is stored in advance in the ROM 12 in a look-up table (map) format.

In the alarm sound information 80, the output start time Tsth (Tss) is set instead of the output start distance Lsth, and the continuous sound start time Tcts (Tcs) is set instead of the continuous sound start distance Lcts. When the minimum TTC this time is larger than the continuous sound start time Tct and equal to or less than the output start time Tsth, the CPU 11 determines that the intermittent sound condition is satisfied and notifies the intermittent sound. On the other hand, when the minimum TTC this time is equal to or less than the continuous sound start time Tct, the CPU 11 determines that the continuous sound condition is satisfied and notifies the continuous sound.

Further, in the alarm sound information 80 shown in FIG. 8, when the collision required time TTC is larger than the continuous sound start time Tct and is equal to or less than the output start time Tsth, the stop time Toff is such that the collision required time TTC is a predetermined time (Tds). It is stipulated that the amount of step reduction is gradually reduced by the amount of GDA (Tgms).

When the minimum TTC this time is equal to or less than the output start time Tsth (Tss), the CPU 11 determines "Yes" in step 735 shown in FIG. 7, executes the processes of steps 625 and 630, and proceeds to step 740.

In step 740, the CPU 11 refers to the alarm sound information 80 and sets the output time Ton and the stop time Tof corresponding to the minimum TTC this time. More specifically, when the minimum TTC this time is equal to or less than the continuous sound start time Tcts (Tcs), the CPU 11 sets the output time Ton to "Tcms" and the stop time Toff to "0ms". On the other hand, when the minimum TTC this time is larger than the continuous sound start time Tcs (Tcs) and is equal to or less than the output start time Tsth (Tss), the CPU 11 sets the output time Ton to "Tims" and stops. Set the time Toff to the time corresponding to the minimum TTC this time.

Next, the CPU 11 proceeds to step 640, starts outputting an alarm sound from the speaker 31, proceeds to step 795, and temporarily ends this routine.

If the value of the notification flag is "1" when the CPU 11 executes the process of step 610, the CPU 11 determines "No" in step 610, proceeds to step 645, and sets the timer TM value to "1". 1 ”is added, and the process proceeds to step 650. In step 650, the CPU 11 determines whether or not the value of the timer TM is equal to or greater than the value obtained by adding the output time Ton and the stop time Toff set in step 740 (hereinafter, referred to as “addition value”). Is determined. If the value of the timer TM is equal to or greater than the added value, the CPU 11 determines "Yes" in step 650, proceeds to step 670, sets the value of the notification flag to "0", and performs processing after step 730. move on.

If the minimum TTC this time is equal to or greater than the previous minimum TTC at the time when the CPU 11 executes the process of step 730, the CPU 11 determines "No" in step 730, proceeds to step 795, and temporarily ends this routine.

If the minimum TTC is larger than the output start time Tsth at the time when the CPU 11 executes the process of step 735, the CPU 11 determines "No" in step 735, proceeds to step 795, and temporarily ends this routine. ..

As can be understood from the above example, in the modified example of the first device, the minimum stop time that can be set by the intermittent sound control even when the collision required time TTC is adopted as the contact index value instead of the distance L. The Toff is set to at least one value of the step reduction amount GDA and the output time Ton in the intermittent sound control. This makes it possible to improve the possibility that the driver can determine that the intermittent sound has been switched to the continuous sound, and the driver mistakenly thinks that the intermittent sound is generated even though the continuous sound is generated. The possibility of recognition can be reduced.

In FIG. 7, the process corresponding to step 613 shown in FIG. 6, that is, the process of determining whether or not the minimum TTC is equal to or less than the continuous sound start time Tch is not executed, but the process is executed. You may.

<Second Embodiment>
Next, the alarm sound output device (hereinafter, may be referred to as "second device") according to the second embodiment of the present invention will be described. Even during the notification of the intermittent sound, the second device sets the intermittent sound being notified to the minimum distance Lmin this time when it is necessary to change the stop time Toff because the minimum distance Lmin this time is smaller than the minimum distance Lmin last time. It differs from the first device in that it is changed so as to have a new output time Ton and a stop time Tof corresponding to. Hereinafter, this difference will be mainly described.

Using FIG. 9, when the current minimum distance Lmin newly acquired during the notification of the intermittent sound satisfies the intermittent sound condition, the second device corresponds to the new minimum distance Lmin of the current time. The process of changing to an intermittent sound will be described.

As shown in FIG. 9, when the intermittent sound condition is satisfied because the minimum distance Lmin is equal to or less than the output start distance Lsth (Lscm) at the time point t1, the second device starts the notification of the intermittent sound. In this intermittent sound, the output time Ton (Times) and the stop time Toff (To1ms) corresponding to the minimum distance Lmin (Lscm) are set. Specifically, the second device starts to output the alarm sound from the speaker 31 from the time point t1, and from "the time point t2 when the output time Ton (Times) elapses from the time point t1" to "the stop time Toff (To1 ms) from the time point t2). The output of the alarm sound is stopped until "t3" when

Here, it is assumed that the minimum distance Lmin (L3 cm (<Lscm) (see FIG. 4)) is newly acquired this time during the notification of the intermittent sound described above. The stop time Toff for the minimum distance Lmin (L3 cm) this time is "To2 ms", which is shorter than the stop time Toff (To1 ms) for the previous minimum distance Lmin (Lscm). Therefore, the second device changes the intermittent sound being notified to the intermittent sound corresponding to the new minimum distance Lmin (L3 cm) this time.

More specifically, when the minimum distance Lmin (L3 cm) is acquired this time, the second device refers to the alarm sound information 40, and the output time Ton (Tims) corresponding to the new minimum distance Lmin (L3 cm) this time and The stop time Toff (To2ms) is acquired. Then, if this time point is "a time point t3a before the new stop time Toff (To2ms) elapses from the time point t2 when the output of the alarm sound in the intermittent sound being notified is stopped", the second device is the time point when the output is stopped t2. The output of the alarm sound is stopped until the time t3a when the new stop time Toff (To2ms) elapses, and the output of the alarm sound is started at the time point t3a. As a result, the intermittent sound notification period during notification is from the time point t1 to the time point t3, but the intermittent sound notification period after the change is from the point t1 to the time point t3a. Since the new output time Ton (Tims) is the same as the output time Ton (Tims) of the intermittent sound being notified, there is no need to newly set it.

Similarly, when a new minimum distance Lmin (L3 cm) is acquired this time during the output of the alarm sound (between time point t1 and time point t2), the second device has passed a new stop time Toff (To2 ms). The output of the alarm sound is started at the time point t3a.

On the other hand, as shown in the third stage of FIG. 9, the time when the new minimum distance Lmin (L3 cm) is acquired this time is "a new stop from the time when the output of the alarm sound in the intermittent sound being notified is stopped t2. If the time point t3b after the time Tof (To2ms) has elapsed, the second device sets a new output time Ton (Tims) and stop time Toff (To2ms) at the time point tb, and outputs an alarm sound. Is started, and the notification of the intermittent sound is started. As a result, if the changed intermittent sound notification period has expired at the time of acquisition of the new minimum distance Lmin, the intermittent sound notification based on the output time Ton and stop time Toff corresponding to the new minimum distance Lmin this time is immediately notified. Is started.

As can be understood from the above example, the second device has a minimum distance Lmin this time, which is a stop time Toff smaller than the stop time Toff of the intermittent sound during the notification of the intermittent sound having a predetermined intermittent sound notification period. When acquired, the stop time Toff of the intermittent sound being notified is changed to the stop time Toff for the minimum distance Lmin this time. The driver can recognize the distance between the latest target and the SV of the own vehicle by the stop time Toff after the change of the intermittent sound.

Next, using the example shown in FIG. 10, the minimum distance Lmin newly acquired during the notification of the intermittent sound satisfies the continuous sound condition, whereby the second device makes the intermittent sound being notified continuous sound. The process to be executed to change to is described.

In the example shown in FIG. 10, the minimum distance Lmin becomes equal to or less than the output start distance Lsth (Lscm) at the time point t1, and the intermittent sound condition is satisfied. Therefore, the second device starts the notification of the intermittent sound. Since the method of generating the intermittent sound is as described with reference to FIG. 9, detailed description thereof will be omitted. In this example, the minimum distance Lmin acquired at the time point t1 is larger than the "value obtained by subtracting the predetermined length (Ldcm) from the output start distance Lsth (Lscm)" and equal to or less than the output start distance Lsth (Lscm). However, if the intermittent sound distance Li is used, other values may be used (that is, the distance may be larger than the continuous sound start distance Lcts and less than or equal to the output start distance Lsth).

Here, it is assumed that the minimum distance Lmin (L8 cm (see FIG. 4)) is newly acquired at the “time point tc, time point td, or time point te” shown in FIG. This time, the minimum distance Lmin (L8 cm) satisfies the continuous sound condition. Therefore, the second device needs to notify the continuous sound at a desired time as soon as possible.

In this case, the processing of the second device differs depending on which of the following (1) and (2) is in the intermittent sound being notified when the new minimum distance Lmin is acquired this time.
(1) When the acquisition time point of the new minimum distance Lmin this time is during the output of the alarm sound of the intermittent sound being notified (see the time point ct shown in FIG. 10), and the acquisition time point of the new minimum distance Lmin this time. Is any of the cases from the output stop time t2 of the intermittent sound being notified to the "time point t9 when the minimum stop time Toff elapses from the output stop time t2" (see the time point td shown in FIG. 10). 2) When the acquisition time point of the new minimum distance Lmin this time is after the time point t9 and until "the time point t3 when the stop time Toff of the intermittent sound being notified elapses from the output stop time t2" (Fig. 10). See point point te.)

First, the processing of the second apparatus in the case of (1) described above will be described.
The acquisition time points tc and td of the minimum distance Lmin this time are the time points before the above-mentioned time point t9 elapses from the time point t2 when the output of the alarm sound is stopped in the intermittent sound being notified. In this case, the second device starts to output the alarm sound at "the time point t9 when the minimum stop time Toff elapses from the time point t2" and starts the notification of the continuous sound. That is, the second device starts outputting the alarm sound at the time point t9, and continues to output the alarm sound until "the time point t10 when the output time Ton (Tcms) elapses from the time point t9". When the minimum distance Lmin acquired at the time point t10 is equal to or less than the continuous sound start distance Lct, the continuous sound notification is continued. When the minimum distance Lmin acquired at the time point t10 is larger than the continuous sound start distance Lct, the continuous sound notification ends. In this case, if the minimum distance Lmin acquired at the time point t10 is smaller than the previous minimum distance Lmin and the minimum distance Lmin acquired at the time point t10 is equal to or less than the output start distance Lsth, the time point t10 , The notification of the intermittent sound corresponding to the minimum distance Lmin starts.

As a result, the alarm sound in the continuous sound starts to be output when the minimum stop time Toff (Times) elapses from the time when the output of the alarm sound in the intermittent sound is stopped. Therefore, while improving the possibility that the driver can discriminate between the intermittent sound and the continuous sound, it is possible to promptly notify the driver that the target of the distance L satisfying the continuous sound condition is detected.

Next, the processing of the second apparatus in the case of (2) described above will be described.
The second device outputs an alarm sound at the output time Ton (Tcms) and the stop time Toff (0 ms) at the time point te, and starts the notification of the continuous sound. That is, the second device starts the output of the alarm sound at the time point te, and continues to output the alarm sound at least until "the time point t11 when the output time Ton (Tcms) elapses from the time point te". As a result, it is possible to promptly notify the driver that a target with a distance L satisfying the continuous sound condition has been detected.

In the case of (1) described above, the second device is a continuous sound without waiting for the elapse of the minimum stop time Toff from the time when the output of the alarm sound in the intermittent sound is stopped, as in (2). When the condition is satisfied, the continuous sound notification may be started.

In the above example, the example in which the second device is applied to the first device has been described, but the second device can also be applied to a modified example of the first device.

The present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention. In the first device and the second device, the larger the absolute value of the vehicle speed of the own vehicle SV, the longer the "length of the distance L required for the stop time Toff to change by the step reduction amount GDA" may be increased. For example, when the absolute value of the vehicle speed of the own vehicle SV is the threshold speed V1th or less, the length of the distance L corresponding to the step reduction amount GDA (Tgms) is set to "Ldcm" in the first device and the second device. The alarm sound information 40 shown in FIG. 4 is used as the low-speed alarm sound information. Then, the first device and the second device refer to the low-speed alarm sound information and execute the above-described processing. On the other hand, when the absolute value of the vehicle speed of the own vehicle SV is larger than the threshold speed V1th, the length of the distance L corresponding to the step reduction amount GDA (Tgms) is larger than "Ldcm" in the first device and the second device. The alarm sound information (not shown) set in the value is used as the high-speed alarm sound information. Then, the first device and the second device refer to the high-speed alarm sound information and execute the above-described processing.

As a result, when the own vehicle SV and the target approach each other, the interval at which the stop time Toff of the intermittent sound when the absolute value of the speed of the own vehicle SV is large becomes shorter, and the speed of the own vehicle SV When the absolute value is small, it is possible to prevent the interval at which the stop time Toff of the intermittent sound is shortened from being significantly different. Depending on the absolute value of the speed of the own vehicle, it can be difficult for the driver to remember the discomfort that this interval is different.

Even if the length of the distance L corresponding to the thus-step reduction GDA is variable, the minimum stop time Toff is set to be longer than the minimum value of the phase reduction GDA.

The alarm sound information 40 may at least specify a distance L satisfying the intermittent sound condition and a stop time Toff corresponding to the distance L, and may not specify an output time Ton for the distance L. In this case, the first device and the second device set the output time Ton (Tcms) and the stop time Toff (0 ms) without referring to the alarm sound information 40 when the minimum distance Lmin satisfies the continuous sound condition this time. .. Further, when the minimum distance Lmin satisfies the intermittent sound condition this time, the first device and the second device set the output time Ton (Times) without referring to the alarm sound information 40, and refer to the alarm sound information 40. This time, the stop time Tof corresponding to the minimum distance Lmin is set.

Similarly, the warning sound information 80 only needs to specify at least a collision required time TTC that satisfies the intermittent sound condition and a stop time Toff corresponding to the collision required time TTC, and the output time Ton for the distance L is specified. It does not have to be.

When either the intermittent sound or the continuous sound is notified, a display element for guiding the driver's line of sight to the position of the target that triggered the notification of the intermittent sound and the continuous sound is provided in the own vehicle SV. It may be displayed on a display (not shown).

Further, instead of the ultrasonic sensor 21 that measures the distance between the own vehicle SV and the target, a millimeter wave radar, a stereo camera, or the like may be used. The millimeter-wave radar detects the distance to a target and the direction of the target by emitting radio waves in the millimeter-wave band (hereinafter referred to as "millimeter wave") instead of ultrasonic waves. The stereo camera includes a left camera that captures a left image and a right camera that captures the right side, and detects the distance to the target and the direction of the target using the parallax between the left image and the right image.

10 ... Alarm sound output ECU, 11 ... CPU, 12 ... ROM, 13 ... RAM, 21A to 21F ... Ultrasonic sensor, 22 ... Vehicle condition sensor, 31 ... Speaker, 40 and 80 ... Alarm sound information.

Claims (5)

The target information acquisition unit that acquires target information including the distance between the target and the own vehicle,
An alarm sound sounding part that can sound an alarm sound, and
A control unit for causing the alarm sound sounding unit to sound the alarm sound is provided.
The control unit
The index value calculated based on the target information and indicating a smaller value as the possibility of contact between the target and the own vehicle is higher than the first threshold value and smaller than the first threshold value than the second threshold value. When the intermittent sound condition is satisfied, the alarm sound is started to be sounded, and the sound of the warning sound is stopped when a predetermined output time elapses from the time when the warning sound is started to be sounded. After a predetermined stop time has elapsed from the time when the sounding of the warning sound is stopped, the warning sound sounding unit is made to sound an intermittent sound pattern that starts the sounding of the warning sound again.
In an alarm sound output device that causes the alarm sound sounding unit to sound a continuous sound pattern that keeps sounding the alarm sound when the continuous sound condition in which the index value is equal to or less than the second threshold value is satisfied.
The control unit
If the intermittent sound conditions are satisfied, the index value is reduced the stop time by a predetermined distance as you decrease by a predetermined amount, the larger the absolute value of the velocity of the vehicle, the stop time is the The stop time when the predetermined amount of the index value required for shortening by a predetermined interval becomes large and the index value for satisfying the intermittent sound condition is the smallest is set longer than the predetermined interval.
Alarm sound output device configured as. In the alarm sound output device according to claim 1,
The control unit
The stop time when the index value for satisfying the intermittent sound condition is the smallest is set to be equal to or longer than the output time.
Alarm sound output device configured as. In the alarm sound output device according to claim 1 or 2.
The control unit
When the continuous sound condition is satisfied when the index value becomes equal to or less than the second threshold value during the sounding of the intermittent sound pattern of the stop time when the index value for satisfying the intermittent sound condition is the smallest, the above-mentioned When the stop time of the intermittent sound pattern being sounded elapses after the continuous sound condition is satisfied, the continuous sound pattern is started to be sounded by the alarm sound sounding unit.
Alarm sound output device configured as. In the alarm sound output device according to claim 1 or 2.
The control unit
When the continuous sound condition is satisfied when the index value becomes equal to or less than the second threshold value during the sounding of the intermittent sound pattern of the stop time when the index value for satisfying the intermittent sound condition is the smallest, the above-mentioned When the continuous sound condition is satisfied, the continuous sound pattern is started to be sounded by the alarm sound sounding unit.
An alarm sound output device configured as follows. In the alarm sound output device according to claim 1,
The control unit
Using the distance between the target and the own vehicle as the index value,
When the distance is equal to or less than the first threshold value and larger than the second threshold value, the intermittent sound condition is satisfied, and the intermittent sound pattern is made to sound by the alarm sound sounding unit.
When the distance is equal to or less than the second threshold value, the continuous sound condition is satisfied, and the continuous sound pattern is made to sound by the alarm sound sounding unit.
Further, when the intermittent sound condition is satisfied, the stop time is shortened by the predetermined interval as the distance becomes smaller, and the stop time when the distance for satisfying the intermittent sound condition is the smallest is set. , Set longer than the predetermined interval,
Alarm sound output device configured as.

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