JP2013186742A - Warning sound output device, warning sound output method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output warning according to an own vehicle's situation to enable a driver to determine degree of danger.SOLUTION: When a driver looks aside while driving a vehicle, and if there is a vehicle travelling ahead, a warning sound with a pitch according to a positional relation between the own vehicle and the vehicle travelling ahead is set. In particular, the warning sound with the pitch and volume according to the positional relation between the own vehicle and the vehicle travelling ahead is output. Or the warning sound is output with output timing according to the positional relation between the own vehicle and the vehicle travelling ahead. The driver can instinctively determine the degree of danger the own vehicle faces, by hearing the warning sound.

Description

  The present invention relates to an alarm sound output device, an alarm sound output method, and a program. More specifically, the present invention relates to an alarm sound output device that outputs an alarm sound to a vehicle driver, and an alarm sound output method for outputting an alarm sound to a vehicle driver. And the program.

  In recent years, the number of traffic fatalities has been decreasing, but the number of accidents has remained at a high level. Although the causes of accidents vary, one of the causes of accidents is that the driver performs actions other than driving, such as conversation or looking aside while driving.

  Thus, various devices have been proposed for alerting the driver to issue a warning to the driver who performs an action other than driving (see, for example, Patent Document 1). When an apparatus described in Patent Document 1 detects an object existing in front of a vehicle, the apparatus outputs a sound having a pitch or a timbre corresponding to the detected object.

JP 2005-125953 A

  According to the device described in Patent Document 1, the driver can roughly specify an object existing in front by viewing audio. However, the alarm sound from the device changes in tone color and pitch depending on the type of detected obstacle, but does not change depending on the positional relationship between the obstacle and the vehicle. Therefore, even if the driver hears an alarm sound, the driver cannot accurately grasp the positional relationship between the obstacle and the vehicle, and intuitively determine how dangerous the vehicle is. I can't.

  The present invention has been made under the above circumstances, and an object of the present invention is to enable a driver to determine the degree of danger of the vehicle by outputting an alarm sound according to the situation of the vehicle.

In order to achieve the above object, an alarm sound output device according to the first aspect of the present invention includes:
Object detection means for detecting objects around the vehicle;
Aside driving detection means for detecting aside driving of the driver of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. Alarm sound output means for outputting as an alarm sound;
Is provided.

The alarm sound output method according to the second aspect of the present invention is:
Detecting an object around the vehicle;
Detecting the driver's aside driving of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. A process of outputting as an alarm sound,
including.

The program according to the third aspect of the present invention is:
On the computer,
A procedure for detecting objects around the vehicle;
A procedure for detecting a driver's armpit driving of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. , Procedure to output as alarm sound,
Is executed.

  According to the present invention, an alarm sound corresponding to the positional relationship between an object and a vehicle is output. Therefore, the driver can determine the degree of danger of the own vehicle by listening to the warning sound.

It is a block diagram of an alarm sound output device concerning a 1st embodiment. It is a figure for demonstrating the attachment position of the imaging device inside a vehicle. It is a figure which shows the image image | photographed by the vehicle interior imaging device. It is a flowchart which shows the process performed by CPU. It is a figure which shows the graph showing the relationship between an index value and a pitch. It is a figure which shows the curve showing the change of a pitch, and the broken line showing the change of collision time. It is a block diagram of an alarm sound output device concerning a 2nd embodiment. It is a figure for demonstrating the attachment position of an imaging device outside a vehicle. It is a figure which shows the image image | photographed with the imaging device outside a vehicle. It is a flowchart which shows the process performed by CPU. It is FIG. (1) which shows the image which the vehicle which drive | works ahead of the own vehicle is reflected. It is a figure (the 2) which shows the image which the vehicle which drive | works ahead of the own vehicle is reflected. It is a figure which shows the graph showing the relationship between a viewing angle change rate and a pitch. It is a figure which shows the curve showing the change of a pitch. It is a figure for demonstrating the output timing of an alarm sound. It is a block diagram of an alarm sound output device concerning a modification.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an alarm sound output device 10 according to the present embodiment. The warning sound output device 10 is a device that outputs a warning sound according to the vehicle situation to the driver. As shown in FIG. 1, the alarm sound output device 10 includes a control device 20, a millimeter wave radar device 31, an in-vehicle imaging device 32, and an alarm device 33.

  The millimeter wave radar device 31 is, for example, an FM-CW radar device using an electromagnetic wave having a frequency of 60 GHz. The millimeter wave radar device 31 measures a distance D from the vehicle 100 to a traveling vehicle traveling in front of the vehicle 100 and a relative speed V of the traveling vehicle with respect to the vehicle 100. Then, the measurement result is output to the control device 20.

  The in-vehicle photographing device 32 is a camera that outputs image information generated by photographing a subject. For example, as shown in FIG. 2, the in-vehicle imaging device 32 is attached to a steering column that supports the steering 101 operated by the driver 50, a dashboard, or the like.

  FIG. 3 is a diagram illustrating an example of an image PI photographed by the in-car photographing device 32. As can be seen from FIG. 3, the face of the driver 50 driving the vehicle 100 is shown in the image PI. As can be seen by referring to this image PI, the viewing angle, the magnification, and the posture of the in-vehicle imaging device 32 are adjusted so that the face of the driver 50 seated on the seat 102 is located in the field of view. Then, the in-vehicle photographing device 32 photographs the face of the driver 50 at a predetermined frame rate, and sequentially outputs image information obtained by photographing to the control device 20.

  Returning to FIG. 1, the alarm device 33 is a device that outputs an alarm sound to the driver 50 driving the vehicle 100. When the alarm device 33 receives an alarm output command output from the control device 20, the alarm device 33 outputs an alarm sound having a pitch corresponding to the alarm output command.

  The control device 20 is a computer having a CPU (Central Processing Unit) 21, a main storage unit 22, an auxiliary storage unit 23, a display unit 24, an input unit 25, and an interface unit 26.

  The CPU 21 detects a vehicle traveling in front of the vehicle 100 and an obstacle based on information output from the millimeter wave radar device 31 according to a program stored in the auxiliary storage unit 23. Further, based on the image information output from the in-vehicle photographing device 32, the driver's 50 look-aside luck is detected. Then, an alarm output command is output to the alarm device 33 according to the detection result. Detailed operation of the CPU 21 will be described later.

  The main storage unit 22 includes a RAM (Random Access Memory) and the like. The main storage unit 22 is used as a work area for the CPU 21.

  The auxiliary storage unit 23 includes a nonvolatile memory such as a ROM (Read Only Memory), a magnetic disk, and a semiconductor memory. The auxiliary storage unit 23 stores programs executed by the CPU 21, various parameters, and the like. Further, information including image information output from the millimeter wave radar device 31 and the in-vehicle imaging device 32, and a processing result by the CPU 21 is sequentially stored.

  The display unit 24 includes a display unit such as an LCD (Liquid Crystal Display). The display unit 24 displays a processing result of the CPU 21, a message to the driver 50, and the like.

  The input unit 25 includes input keys and a pointing device such as a touch panel. The operator's instruction is input via the input unit 25 and is notified to the CPU 21 via the system bus 27.

  The interface unit 26 includes a serial interface or a LAN (Local Area Network) interface. The millimeter wave radar device 31, the in-vehicle imaging device 32, and the alarm device 33 are connected to the system bus 27 via the interface unit 26.

  Next, the operation of the alarm sound output device 10 configured as described above will be described. The flowchart shown in FIG. 4 shows a series of processing executed by the CPU 21 of the control device 20. This flowchart corresponds to the algorithm of the program executed by the CPU 21. Hereinafter, the operation of the alarm sound output device 10 will be described with reference to FIG. When the ignition switch is operated by the driver 50 and the alarm sound output device 10 is turned on, the CPU 21 executes a series of processes shown in FIG.

  First, in step S <b> 201, the CPU 21 measures the distance D from the vehicle 100 to the obstacle located in front of the vehicle 100 and the relative velocity V of the obstacle with respect to the vehicle 100 based on the output from the millimeter wave radar device 31. Try.

  For example, when another vehicle (hereinafter referred to as a traveling vehicle) is traveling in front of the vehicle 100, the millimeter wave radar device 31 causes the distance D from the vehicle 100 to the traveling vehicle and the relative of the traveling vehicle to the vehicle 100. The speed V is measured and output. On the other hand, when there is no obstacle in front of the vehicle 100, the millimeter wave radar device 31 does not output information regarding the distance D and the relative speed V. When the CPU 21 detects information related to the distance D and the relative velocity V output from the millimeter wave radar device 31 (step S201: Yes), the CPU 21 proceeds to step S202.

  In step S <b> 202, the CPU 21 tries to detect the aside operation by the driver 50. Specifically, the CPU 21 extracts the face image of the driver 50 from each of the images PI defined by the image information sequentially output from the in-vehicle photographing device 32. Next, a change in the direction of the line of sight of the driver 50 or the direction of the face is detected from the extracted face image. Then, when it is determined that the direction of the line of sight or the direction of the face has changed significantly, it is determined that the driver 50 has performed the look-aside driving (step S202: Yes). The above-mentioned detection of the aside look driving can be performed using a known technique. When the determination in step S202 is affirmed, the CPU 21 proceeds to the next step S203.

  In step S <b> 203, the CPU 21 calculates a time until the traveling vehicle collides with the vehicle 100 (hereinafter referred to as a collision time TTC). The collision time TTC is calculated by dividing the distance D detected in step S201 by the relative speed V.

  In the next step S204, the CPU 21 sets the pitch of the alarm sound based on the index value a2 / TTC obtained by dividing the constant a2 by the collision time TTC. FIG. 5 shows a graph showing the relationship between the index value a2 / TTC and the pitch. As shown in FIG. 5, the CPU 21 sets an alarm sound having a pitch corresponding to the index value a2 / TTC. Thereby, the pitch of the alarm sound is proportional to the reciprocal of the collision time TTC.

  The value of the constant a2 is equal to the collision avoidance time, for example. The collision avoidance time is a time required for the driver 50 who has noticed the approach of the traveling vehicle to avoid the collision safely. When the index value a2 / TTC is 1 or less, that is, when the collision time TTC is equal to or longer than the collision avoidance time, the CPU 21 sets the pitch of the alarm sound as a1. When the index value a2 / TTC exceeds 1, that is, when the collision time TTC is shorter than the collision avoidance time, the pitch of the alarm sound is set to a1 + k (a2 / TTC). Note that k is a proportional constant.

  In the next step S205, the CPU 21 notifies the alarm device 33 of the pitch set in step S204 and outputs an alarm sound output command to the alarm device 33. Thereby, the alarm device 33 outputs an alarm sound having the pitch set in step S204.

  When the CPU 21 finishes the process of step S205, it returns to step S201, and thereafter repeatedly executes the processes of steps S201 to S205. As a result, when the driver 50 is driving aside, the vehicle 100 approaches the traveling vehicle, and if the collision time TTC becomes shorter than the collision avoidance time (= a2), the pitch of the warning sound gradually increases. To go. On the other hand, when the driver 50 is looking aside, if the collision time TTC becomes longer than the collision avoidance time (= a2), the pitch of the warning sound is maintained constant.

  In FIG. 6, a curve representing a change in pitch is shown by a solid line, and a curve showing a change in collision time TTC is shown by a dotted line. These curves are seen, for example, when the distance between the vehicle 100 and the traveling vehicle is constant from time t1 to time t2, and the traveling vehicle starts approaching the vehicle 100 at a constant relative speed from time t2. It is.

  As shown in FIG. 6, in this case, the collision time TTC starts to decrease from time t2, and the collision time TTC becomes equal to the collision avoidance time at time t3. Therefore, until the time t3, the pitch of the alarm sound is kept constant at a1. After time t3, the collision time TTC gradually becomes smaller than the collision avoidance time. In this case, the pitch of the alarm sound becomes higher in series.

  As described above, in the present embodiment, when there is a vehicle traveling in front of the vehicle 100 when the driver 50 driving the vehicle 100 performs a side-view driving, the vehicle 100 and the traveling vehicle An alarm sound having a pitch corresponding to the positional relationship is output to the driver 50 who performs the look-aside operation.

  Specifically, when the collision time TTC is longer than the collision avoidance time and the degree of danger is relatively small, an alarm sound having a pitch a1 (hereinafter referred to as a basic sound) is output. On the other hand, when the collision time TTC becomes shorter than the collision avoidance time, an alarm sound having a pitch higher than the basic sound is output. The pitch of this warning sound increases as the collision time TTC decreases.

  Therefore, the driver 50 driving the vehicle 100 can intuitively determine the degree of danger that the host vehicle faces by listening to the alarm sound.

  The viewing angle change rate DR is proportional to the reciprocal of the collision time TTC, as can be seen by referring to the following equation (1).

  Therefore, increasing the pitch of the basic sound so as to be proportional to the reciprocal of the collision time TTC is equivalent to increasing the basic sound so as to be proportional to the viewing angle change rate DR.

  In this embodiment, the case where the alarm sound output device 10 includes the millimeter wave radar device 31 has been described. However, the present invention is not limited to this, and a radar that uses electromagnetic waves of other frequencies instead of the millimeter wave radar device 31. An apparatus may be used.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to the drawings. In addition, about the structure same or equivalent to 1st Embodiment, while using an equivalent code | symbol, the description is abbreviate | omitted or simplified.

  FIG. 7 is a block diagram of an alarm sound output device 10A according to the present embodiment. As shown in FIG. 7, the alarm sound output device 10 </ b> A according to the present embodiment includes an outside-vehicle imaging device 35 instead of the millimeter wave radar device 31, and the alarm sound output device 10 according to the first embodiment. Is different.

  The outside-vehicle photographing device 35 is a camera that outputs image information generated by photographing a subject. For example, as shown in FIG. 8, the outside-vehicle photographing device 35 is attached to the upper part of the front window of the vehicle 100.

  FIG. 9 is a diagram illustrating an example of an image PO photographed by the outside-vehicle photographing device 35. As can be seen from FIG. 9, a road on which the vehicle 100 travels, a vehicle traveling in front of the vehicle 100, and the like are reflected in the image PO. As can be seen by referring to this image PO, the in-vehicle photographing device 35 has a viewing angle, a magnification and a posture so that a road on which the vehicle 100 travels, a vehicle traveling in front of the vehicle 100, and the like are located within the field of view. It has been adjusted. The outside-vehicle photographing device 35 photographs the traveling direction of the vehicle 100 at a predetermined frame rate, and sequentially outputs image information obtained by photographing to the control device 20.

  Next, the operation of the alarm sound output device 10A will be described. The flowchart shown in FIG. 10 shows a series of processes executed by the CPU 21. This flowchart corresponds to the algorithm of the program executed by the CPU 21. Hereinafter, the operation of the alarm sound output device 10A will be described with reference to FIG. When the ignition switch is operated by the driver 50 and the alarm sound output device 10A is turned on, the CPU 21 executes a series of processes shown in FIG.

First, the CPU 21 tries to detect an obstacle located in front of the vehicle 100 in step S301. The obstacle detection process is performed based on the image information output from the outside-vehicle photographing device 35. Specifically, the CPU 21 extracts the feature point P1 _M from the image PO ₁ defined by the image information, and extracts the feature point P2 _N from the image PO ₂ photographed next to the image PO ₁ . M and N are integers. Next, an optical flow having a feature point P1 as a start point and a corresponding feature point P2 as an end point is extracted. Then, optical flows having the same vanishing point are grouped.

  The characteristic points that define the optical flows that are grouped as described above exist in, for example, an image of a vehicle or an obstacle traveling in front of the vehicle 100. Therefore, the CPU 21 determines that an obstacle such as a vehicle exists in the traveling direction of the vehicle 100 when there is an image including a predetermined number of feature points P1 or feature points P2 constituting the grouped optical flow (step S301). : Yes). The above-described obstacle detection can be performed using a known technique. If the determination in step S301 is affirmed, the CPU 21 proceeds to step S302.

  In step S <b> 302, the CPU 21 tries to detect the aside operation by the driver 50. Specifically, the CPU 21 extracts the face image of the driver 50 from each of the images PI defined by the image information sequentially output from the in-vehicle photographing device 32. Then, a change in the direction of the line of sight of the driver 50 or the direction of the face is detected from the extracted face image. Then, when it is determined that the direction of the line of sight or the direction of the face has changed significantly, it is determined that the driver 50 has performed the look-aside operation (step S302: Yes). The above-mentioned detection of the aside look driving can be performed using a known technique. When the determination in step S302 is affirmed, the CPU 21 proceeds to next step S303.

In step S303, the CPU 21 calculates the viewing angle change rate DR per unit time. Viewing angle change rate DR is when the viewing angle θ1 of the image of the obstacle in the image PO ₁ as a reference, the ratio of the difference between the viewing angle θ2 of viewing angles θ1 and the image PO _2.

FIG. 11 is a diagram illustrating an image PO _{1 in} which a vehicle 120 traveling in front of the vehicle 100 is captured as an obstacle. FIG. 12 is a diagram illustrating an image PO _{2 in} which the vehicle 120 is captured. When the area of the image of the vehicle 120 in the image PO ₁ is S1 and the area of the image of the vehicle 120 in the image PO ₂ is S2, the viewing angle change rate DR can be calculated based on the following equation (2). Note that FR is a frame rate of the outside-vehicle photographing device 35.

  DR = (S2-S1) / S1 / fr (2)

  The viewing angle change rate DR is smaller than 0 when the vehicle 120 moves away from the vehicle 100, and is larger than 0 when the vehicle 120 approaches the vehicle 100. In addition, when the vehicle 100 and the vehicle 120 travel at the same speed and the distance between the vehicle 100 and the vehicle 120 does not change, the value is zero.

  In the next step S304, the CPU 21 sets the pitch of the alarm sound based on the viewing angle change rate DR. FIG. 13 shows a graph showing the relationship between the viewing angle change rate DR and the pitch. As shown in FIG. 13, the CPU 21 sets an alarm sound having a pitch according to the viewing angle change rate DR. For example, when the viewing angle change rate DR is 0 or less, the pitch of the alarm sound is set to a1. When the viewing angle change rate DR exceeds 0, the pitch of the alarm sound is set to a1 + k · DR. Note that k is a proportional constant.

  In the next step S305, the CPU 21 notifies the alarm device 33 of the pitch set in step S304 and outputs an alarm sound output command to the alarm device 33. Thereby, the alarm device 33 outputs an alarm sound having a pitch set in step S304.

  When the CPU 21 finishes the process of step S305, the CPU 21 returns to step S301, and thereafter repeatedly executes the processes of steps S301 to S305. Thereby, when the driver 50 is driving aside, as the vehicle 100 approaches the vehicle 120, the pitch of the alarm sound gradually increases. On the other hand, when the driver 50 is looking aside and the vehicle 120 moves away from the vehicle 100, the pitch of the alarm sound is maintained constant.

  FIG. 14 shows a curve indicating a change in pitch. This curve represents the change in the pitch seen when the distance between the vehicle 100 and the vehicle 120 is constant from time t1 to time t2, and the vehicle 120 approaches the vehicle 100 at a constant relative speed after time t2. . As shown in FIG. 10, the interval of the alarm sound is kept constant at a1 from time t1 to time t2. And after the time t2, the pitch of the alarm sound becomes higher in series.

  As described above, in this embodiment, when there is a vehicle 120 traveling in front of the vehicle 100 when the driver 50 driving the vehicle 100 performs a side-view driving, the vehicle 100 and the vehicle 120 are displayed. A warning sound having a pitch corresponding to the positional relationship is output to the driver 50 who performs the look-ahead operation.

  Specifically, when the distance between the vehicles 100 and 120 is constant or the degree of danger is relatively small such that the distance between the vehicles increases, a basic sound with a pitch of a1 is output. On the other hand, when the distance between the vehicle 100 and the vehicle 120 is decreasing, an alarm sound having a pitch higher than the basic sound is output. The pitch of this warning sound increases as the inter-vehicle distance decreases.

  Therefore, the driver 50 driving the vehicle 100 can intuitively determine the degree of danger that the host vehicle faces by listening to the alarm sound.

  As mentioned above, although embodiment of this invention was described, this invention is not limited by the said embodiment.

  For example, in the above embodiment, the case where the pitch of the alarm sound output from the alarm device 33 changes has been described. However, the present invention is not limited to this, and the volume of the alarm sound output from the alarm device 33 may be changed. Moreover, you may change both the volume and pitch of an alarm sound.

  In the above embodiment, the case where the pitch of the alarm sound is changed has been described. For example, as shown in FIG. 15, the alarm sound may be intermittently output at an interval d corresponding to the viewing angle change rate DR or the index value a2 / TTC. In this case, for example, a rectangular wave with a pulse interval of d is output to the alarm device 33 as an alarm sound output command. As a result, the alarm device 33 intermittently outputs an alarm sound at intervals d corresponding to the viewing angle change rate DR or the index value a2 / TTC.

  In the above embodiment, the constant a2 is described as being equivalent to the collision avoidance time. The present invention is not limited to this, and the constant a2 may be larger than the collision avoidance time.

  The program stored in the auxiliary storage unit 23 of the control device 20 is read by a computer such as a flexible disk, a CD-ROM (Compact Disk Read-Only Memory), a DVD (Digital Versatile Disk), or an MO (Magneto-Optical disk). An apparatus that executes the above-described processing may be configured by storing and distributing the program in a possible recording medium and installing the program in a computer.

  In the above embodiment, the alarm sound is output when the CPU 21 executes the program stored in the auxiliary storage unit. Not only this but alarm sound output device 10 may be constituted by hardware as shown in FIG. Specifically, the alarm sound output device 10 may include an object detection unit 11, an aside look operation detection unit 12, and an alarm sound output unit 13.

  The object detection unit 11 obtains the viewing angle change rate DR for the traveling vehicle from the image of the traveling vehicle running in front of the vehicle 100. Alternatively, a distance D to an obstacle such as a traveling vehicle traveling in front of the vehicle 100 and a relative speed V between the vehicle 100 and the obstacle are measured.

  The armpit driving detection unit 12 includes a camera that captures the face of the driver 50 and an image processing device. The aside driving detection unit 12 detects the aside driving of the driver 50 from the face image of the driver 50 driving the vehicle 100.

  The warning sound output unit 13 determines and outputs the pitch of the warning sound based on the outputs from the object detection unit 11 and the armpit driving detection unit 12.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention.

  The alarm sound output device, alarm sound output method and program of the present invention are suitable for outputting an alarm sound to a driver.

10, 10A Alarm sound output device 11 Object detection unit 12 Armpit operation detection unit 13 Alarm sound output unit 20 Controller 21 CPU
DESCRIPTION OF SYMBOLS 22 Main memory part 23 Auxiliary memory part 24 Display part 25 Input part 26 Interface part 27 System bus 31 Millimeter wave radar apparatus 32 In-vehicle imaging device 33 Alarm device 35 Outside imaging device 50 Driver 100 Vehicle 101 Steering 102 Seat 120 Vehicle PI, PO image

Claims (7)

Object detection means for detecting objects around the vehicle;
Aside driving detection means for detecting aside driving of the driver of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. Alarm sound output means for outputting as an alarm sound;
An alarm sound output device comprising: Distance measuring means for measuring the distance between the object and the vehicle;
A relative speed measuring means for measuring a relative speed between the object and the vehicle;
A predicted time calculating unit that calculates a predicted time until the object and the vehicle collide by dividing the distance measured by the distance measuring unit by the relative speed measured by the relative speed measuring unit;
With
The warning sound output device according to claim 1, wherein the warning sound output unit outputs the basic sound changed according to the viewing angle change rate defined from the reciprocal of the predicted time as the warning sound. A photographing means for photographing an image of the object;
The warning sound output means is a second image taken after the first viewing angle and the first image, with the first viewing angle of the object taken in the first image taken by the imaging means as a reference. The warning sound output device according to claim 1, wherein the warning sound is output with a ratio of a difference from the second viewing angle of the object in the image as the viewing angle change rate.   The alarm sound according to any one of claims 1 to 3, wherein the alarm sound output means outputs a basic sound in which at least one of a volume and a pitch is changed according to the viewing angle change rate as the alarm sound. Output device.   The warning sound output device according to claim 4, wherein the warning sound output means outputs a basic sound changed in proportion to the viewing angle change rate as the warning sound. Detecting an object around the vehicle;
Detecting the driver's aside driving of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. A process of outputting as an alarm sound,
Alarm sound output method including. On the computer,
A procedure for detecting objects around the vehicle;
A procedure for detecting a driver's armpit driving of the vehicle;
After the object is detected, when a driver's side aside is detected, the driver is caused to change a predetermined basic sound according to the viewing angle change rate of the object viewed from the driver. , Procedure to output as alarm sound,
A program for running

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