Warning sound control device and warning sound control method

Abstract

To provide a warning sound control device that facilitates recognition of the distance to approaching objects.SOLUTION: A warning sound control device (10) detects an object (30) approaching a moving body (1), determines the direction in which a sound image of the warning sound is localized based on the direction of the object (30) with respect to the moving body (1), and determines the trajectory of the sound image of the warning sound based on the distance from the moving body (1) to the object (30). The warning sound control device (10) then changes the trajectory of the sound image of the warning sound according to the distance from the moving body (1) to the object (30), while making the direction in which the sound image of the warning sound is localized follow the direction of the object (30) relative to the moving body (1).SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a warning sound control device and a warning sound control method that notify a driver of an approaching object by using a warning sound. [Background technology]

[0002] There is known a warning sound control device that detects an object approaching a vehicle and emits a warning sound inside the vehicle to notify the driver of the approaching object. For example, Patent Document 1 discloses a warning sound control device that notifies the driver of the direction in which the object is approaching by localizing the sound image (virtual sound source) of the warning sound in the direction in which the object is located, and that notifies the driver of the distance from the vehicle to the object by making the distance between the sound image of the warning sound and the driver proportional to the distance between the object and the vehicle.

[0003] Furthermore, Patent Document 2 discloses a warning device that moves a sound image presented to the driver of a vehicle and changes the trajectory of the moving sound image to attract the driver's attention. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 145286 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-329754 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, it is more difficult to recognize the distance to a sound image than the direction of the sound image. Therefore, with the warning sound control device of Patent Document 1, it is easy for the driver to recognize the direction of an approaching object, but it is difficult for the driver to recognize the distance to the object.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a warning sound control device that makes it easy to recognize the distance to an approaching object. [Means for solving the problem]

[0007] The warning sound control device according to the present disclosure includes an approaching object detection unit that detects an object approaching a moving body and acquires information on the distance from the moving body to the object and the direction of the object relative to the moving body; a sound image direction determination unit that determines a direction in which to localize a sound image of the warning sound based on the direction of the object relative to the moving body; a sound image trajectory determination unit that determines a trajectory of the sound image of the warning sound based on the distance from the moving body to the object; an audio signal control unit that controls an audio signal of the warning sound so that the sound image of the warning sound is localized in the direction determined by the sound image direction determination unit and moves along the trajectory determined by the sound image trajectory determination unit; and a warning sound output processing unit that outputs the audio signal of the warning sound controlled by the audio signal control unit from a speaker, wherein the sound image direction determination unit causes the direction in which the sound image of the warning sound is localized to follow the direction of the object relative to the moving body, and the audio signal control unit changes the trajectory of the sound image of the warning sound depending on the distance from the moving body to the object. [Effects of the Invention]

[0008] According to the warning sound control device of the present disclosure, the size of the trajectory of the sound image of the warning sound informs the user of the distance to an approaching object, allowing the user to easily recognize the distance to the object. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a configuration of a warning system including a warning sound control device according to a first embodiment. [Figure 2] 1 is a functional block diagram of a warning sound control device according to a first embodiment. [Figure 3] 1 is a diagram illustrating an example of a hardware configuration of a warning sound control device according to a first embodiment. [Figure 4] 4 is a diagram for explaining the operation of the warning sound control device according to the first embodiment. FIG. [Figure 5]4 is a diagram for explaining the operation of the warning sound control device according to the first embodiment. FIG. [Figure 6] 4 is a flowchart showing the operation of the warning sound control device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] <First Embodiment> FIG. 1 is a diagram showing the configuration of a warning system including a warning sound control device 10 according to the first embodiment.

[0011] The warning sound control device 10 is mounted on a vehicle 1, which is a moving body. Hereinafter, the vehicle 1 on which the warning sound control device 10 is mounted will be referred to as the "host vehicle." However, the warning sound control device 10 does not need to be permanently installed on the host vehicle 1, and may be a portable device that can be removed from the host vehicle 1. The warning sound control device 10 may also be realized as an application that runs on a portable terminal such as a mobile phone, smartphone, or PND (Portable Navigation Device).

[0012] The warning sound control device 10 is connected to a camera 2 and a speaker 3 installed in the host vehicle 1. In this embodiment, as shown in FIG. 1 , the host vehicle 1 is equipped with two cameras 2, namely, a camera 2a installed on the right rear of the host vehicle 1 and a camera 2b installed on the left rear of the host vehicle 1. The host vehicle 1 is also equipped with four speakers 3, namely, a speaker 3a installed on the left front of the host vehicle 1, a speaker 3b installed on the left rear of the host vehicle 1, a speaker 3c installed on the right front of the host vehicle 1, and a speaker 3d installed on the right rear of the host vehicle 1.

[0013] However, the number and arrangement of the cameras 2 and speakers 3 are not limited to this. There must be at least one camera 2 and one speaker 3. The camera 2 may be installed in front of the vehicle 1, inside the vehicle 1, on the ceiling of the vehicle 1, etc. The speaker 3 may be installed outside the vehicle 1. Furthermore, since the camera 2 is used as a sensor for detecting objects, it may be replaced with another sensor that has the function of detecting objects, such as an ultrasonic sensor or radar.

[0014] The camera 2 detects an object 30 (another vehicle in FIG. 1 ) present around the vehicle 1, and acquires information on the position of the detected object, specifically, the direction of the object 30 relative to the vehicle 1 and the distance from the vehicle 1 to the object 30. The camera 2 inputs information on the detected object 30 to the warning sound control device 10.

[0015] The warning sound control device 10 determines whether the object 30 is approaching the vehicle 1 (whether there is a possibility of collision with the vehicle 1) based on information about the object 30 input from the camera 2, and if the object 30 is approaching the vehicle 1, controls the speaker 3 to generate a sound image (virtual sound source) of the warning sound. At this time, the warning sound control device 10 determines the position to localize the sound image of the warning sound and the trajectory to move the sound image based on information about the direction and distance of the object 30. Hereinafter, an object approaching the vehicle 1 will be referred to as an "approaching object."

[0016] Fig. 2 is a functional block diagram of the warning sound control device according to embodiment 1. As shown in Fig. 2, the warning sound control device 10 includes an approaching object detection unit 11, a sound image direction determination unit 12, a sound image trajectory determination unit 13, an audio signal control unit 14, and a warning sound output processing unit 15.

[0017] The approaching object detection unit 11 detects an object approaching the host vehicle 1 based on information about the object 30 detected by the camera 2. Specifically, the approaching object detection unit 11 acquires information about the direction of the object 30 relative to the host vehicle 1 and the distance from the host vehicle 1 to the object 30 from the camera 2, and determines whether or not the object 30 is an approaching object based on the information.

[0018] The sound image direction determination unit 12 determines the direction for localizing the sound image of the warning sound based on the direction of the approaching object with respect to the host vehicle 1. Specifically, the sound image direction determination unit 12 sets the direction of the sound image of the warning sound to the same direction as the direction of the approaching object with respect to the driver of the host vehicle 1, who is the user of the warning sound control device 10. Note that the distance from the driver of the host vehicle 1 to the position where the sound image of the warning sound is localized is set to a predetermined constant value.

[0019] The sound image trajectory determination unit 13 determines the trajectory of the sound image of the warning sound based on the distance from the host vehicle 1 to the approaching object. Specifically, the sound image trajectory determination unit 13 changes the size of the trajectory of the sound image of the warning sound (the size of the figure drawn by the trajectory) according to the distance from the host vehicle 1 to the approaching object.

[0020] In the present embodiment, the trajectory of the sound image of the warning sound is a circle with a radius r, and the warning sound control device 10 increases the trajectory of the sound image of the warning sound as the distance from the host vehicle 1 to the approaching object becomes shorter. Specifically, the warning sound control device 10 sets the radius r of the trajectory of the sound image of the warning sound from the distance d from the host vehicle 1 to the approaching object according to the calculation formula of r = A / d (A is an arbitrary positive value). For example, as shown in FIG. 4, if the distance from the host vehicle 1 to the object 30 (other vehicle) is d1, the trajectory of the sound image of the warning sound (the dashed circle) is a circle with a radius r1 = A / d1. Thereafter, as shown in FIG. 5, when the distance from the host vehicle 1 to the object 30 decreases and the distance becomes d2, the trajectory of the sound image of the warning sound is a circle with a radius r2 = A / d2. From the relationship of d1 > d2, the relationship of r1 < r2 is obtained.

[0021] The audio signal control unit 14 controls the audio signal of the warning sound so that the sound image of the warning sound is localized in the direction determined by the sound image direction determination unit 12 and the sound image of the warning sound moves along the trajectory determined by the sound image trajectory determination unit 13.

[0022] The warning sound output processing unit 15 generates the sound image of the warning sound by outputting the audio signal of the warning sound controlled by the audio signal control unit 14 from the speaker 3. As a result, the sound image of the warning sound that moves along the trajectory determined by the sound image trajectory determination unit 13 is generated in the direction determined by the sound image direction determination unit 12.

[0023] When the host vehicle 1 and the object 30 move, the positional relationship between the host vehicle 1 and the object 30 changes. The sound image direction determination unit 12 causes the direction in which the sound image of the warning sound is localized to follow the direction of the approaching object relative to the host vehicle 1. The audio signal control unit 14 widens the trajectory of the sound image of the warning sound as the distance from the host vehicle 1 to the approaching object becomes shorter.

[0024] 3 is a diagram showing an example of the hardware configuration of the warning sound control device 10. As shown in FIG. 3, the warning sound control device 10 can be configured by a CPU 21, a memory 22, a DSP (Digital Signal Processor) 23, and an amplifier 24.

[0025] The CPU 21 executes programs stored in the memory 22 to realize the functions of the approaching object detection unit 11, sound image direction determination unit 12, and sound image trajectory determination unit 13 shown in FIG. 2. The memory 22 also stores parameters used by the sound image direction determination unit 12 and the sound image trajectory determination unit 13 to adjust the position and trajectory of a sound image. The functions of the audio signal control unit 14 and the sound image trajectory determination unit 13 are realized by the DSP 23 and the amplifier 24. The DSP 23 may be included in the CPU 21. That is, the functions of the DSP 23 may be realized by the CPU 21 executing programs.

[0026] 3 shows only one CPU 21, there may be multiple CPUs 21. That is, the functions of the approaching object detection unit 11, the sound image direction determination unit 12, and the sound image trajectory determination unit 13 may be realized by multiple CPUs 21 operating in cooperation with each other. Also, the hardware configuration shown in FIG. 3 is merely an example, and each piece of hardware may be replaced with other hardware that can realize the same function.

[0027] 6 is a flowchart showing the operation of the warning sound control device according to embodiment 1. The operation of the warning sound control device 10 will be described below with reference to the flowchart of FIG.

[0028] The warning sound control device 10 is activated, for example, when the power of the host vehicle 1 is turned on. When the warning sound control device 10 is activated, the approaching object detection unit 11 searches for an object approaching the host vehicle 1 based on information about the object 30 detected by the camera 2 (step ST1). The approaching object detection unit 11 determines whether or not an approaching object has been detected (whether or not the object 30 detected by the camera 2 is an approaching object) (step ST2). If an approaching object is not detected (NO in step ST2), steps ST1 and ST2 are repeatedly executed.

[0029] If an approaching object is detected (YES in step ST2), the sound image direction determination unit 12 and the sound image trajectory determination unit 13 acquire information on the direction of the object 30 relative to the vehicle 1 and the distance from the vehicle 1 to the object 30 from the approaching object detection unit 11 (step ST3).

[0030] Then, the sound image direction determination unit 12 determines the direction in which to localize the sound image of the warning sound based on the direction of the approaching object relative to the host vehicle 1 (step ST4). Specifically, the sound image direction determination unit 12 orients the direction of the sound image of the warning sound in the same direction as the direction of the approaching object relative to the driver of the host vehicle 1.

[0031] Furthermore, the sound image trajectory determination unit 13 determines the trajectory of the sound image of the warning sound based on the distance from the host vehicle 1 to the approaching object (step ST5). Specifically, the sound image trajectory determination unit 13 determines the size of the trajectory of the sound image of the warning sound (the size of the figure drawn by the trajectory). At this time, the warning sound control device 10 makes the trajectory of the sound image of the warning sound larger as the distance from the host vehicle 1 to the approaching object becomes shorter.

[0032] Step ST4 and step ST5 may be performed in any order, or may be performed simultaneously (in parallel).

[0033] Next, the audio signal control unit 14 controls the audio signal of the warning sound so that the sound image of the warning sound is localized in the direction determined by the sound image direction determination unit 12 and moves along the trajectory determined by the sound image trajectory determination unit 13, and the warning sound output processing unit 15 outputs the audio signal of the warning sound controlled by the audio signal control unit 14 from the speaker 3. This generates the sound image of the warning sound (step ST6).

[0034] After that, the process returns to step ST1, and the above processing is repeated. As a result, the direction in which the sound image of the warning sound is localized follows the direction of the approaching object relative to the host vehicle 1, and the trajectory of the sound image of the warning sound becomes larger as the distance from the host vehicle 1 to the approaching object becomes shorter.

[0035] The warning sound control device 10 according to the first embodiment notifies the driver of the host vehicle 1 of the distance from the host vehicle 1 to an approaching object based on the size of the trajectory of the sound image of the warning sound. The size of the trajectory of the sound image of the warning sound corresponds to the magnitude of the change in direction of the sound image relative to the driver of the host vehicle 1. Since it is relatively easy to recognize the direction of a sound image, the driver can easily recognize the distance to the approaching object from the change in the size of the trajectory of the sound image of the warning sound. This makes it easier for the driver to understand the degree of risk of the approaching object colliding with the host vehicle 1.

[0036] <Embodiment 2> In the second embodiment, the sound image trajectory determination unit 13 changes the size of the trajectory of the sound image of the warning sound, taking into consideration not only the distance from the host vehicle 1 to the approaching object but also the speed at which the approaching object approaches the host vehicle 1 (i.e., the relative speed of the approaching object with respect to the host vehicle 1, hereinafter simply referred to as the "relative speed of the approaching object"). Specifically, the sound image trajectory determination unit 13 makes the trajectory of the sound image of the warning sound larger as the relative speed of the moving object increases. The relative speed of the moving object can be calculated from the time-series change in the distance from the host vehicle 1 to the moving object.

[0037] For example, a method is envisioned in which the sound image trajectory determination unit 13 weights the size of the trajectory of the sound image of the warning sound determined by the method of embodiment 1 according to the relative speed of the moving object. This method will be explained assuming that the trajectory of the sound image of the warning sound is a circle with a radius r. For example, if the distance between the host vehicle 1 and the object 30 at time T1 is d3, and the distance between the host vehicle 1 and the object 30 changes to d4 at time T2, ΔT seconds after time T1, the radius r at time T2 is calculated using the formula r = A·v / d4. The weight v is the relative speed of the moving object during the period from time T1 to time T2, and is expressed as v = (d4 - d3) / ΔT.

[0038] In this way, by changing the size of the trajectory of the sound image of the warning sound depending on the relative speed of the approaching object, the driver can more easily grasp the level of risk of the approaching object colliding with the vehicle 1.

[0039] <Third Embodiment> Humans tend to perceive the position of a sound source as higher the frequency of the sound. Therefore, in the third embodiment, the audio signal control unit 14 increases the frequency of the warning sound as the position of the sound image of the warning sound determined by the sound image direction determination unit 12 increases. For example, when the sound image is localized at a height (e.g., distance from the ground) of 1 m, a warning sound of 100 Hz is output, and when the sound image is localized at a height of 3 m, a warning sound of 10 kHz is output.

[0040] This allows the driver of the vehicle 1 to more easily recognize the size of the trajectory of the sound image of the warning sound, and more easily grasp the distance from the vehicle 1 to an approaching object.

[0041] In the above embodiment, the mobile body on which the warning sound control device 10 is mounted has been described as a vehicle, but the warning sound control device 10 can be applied to various mobile bodies, not just vehicles, such as aircraft and ships.

[0042] It is possible to freely combine the embodiments, and to modify or omit the embodiments as appropriate. [Explanation of symbols]

[0043] 1 Vehicle, 2 Camera, 3 Speaker, 10 Warning sound control device, 11 Approaching object detection unit, 12 Sound image direction determination unit, 13 Sound image trajectory determination unit, 14 Audio signal control unit, 15 Warning sound output processing unit, 21 CPU, 22 Memory, 23 DSP, 24 Amplifier, 30 Object.

Claims

1. an approaching object detection unit that detects an object approaching a moving body and acquires information on the distance from the moving body to the object and the direction of the object relative to the moving body; a sound image direction determination unit that determines a direction in which to localize a sound image of a warning sound based on a direction of the object relative to the moving body; a sound image trajectory determination unit that determines a trajectory of a sound image of the warning sound based on a distance from the moving body to the object; an audio signal control unit that controls an audio signal of the warning sound so that the sound image of the warning sound is localized in the direction determined by the sound image direction determination unit and moves along the trajectory determined by the sound image trajectory determination unit; a warning sound output processing unit that outputs the audio signal of the warning sound controlled by the audio signal control unit from a speaker; Equipped with the sound image direction determination unit causes a direction in which the sound image of the warning sound is localized to follow a direction of the object relative to the moving body, the sound signal control unit changes a trajectory of a sound image of the warning sound in accordance with a distance from the moving body to the object. Alarm sound control device.

2. the sound signal control unit increases the trajectory of the sound image of the warning sound as the distance from the moving body to the object decreases. The warning sound control device according to claim 1 .

3. the sound image trajectory determination unit increases the trajectory of the sound image as the relative velocity of the object with respect to the moving body increases, The warning sound control device according to claim 2 .

4. the audio signal control unit controls the audio signal of the warning sound so that the frequency of the warning sound increases as the position of the sound image of the warning sound increases. The warning sound control device according to any one of claims 1 to 3.

5. an approaching object detection unit of the warning sound control device detects an object approaching the moving body and acquires information on the distance from the moving body to the object and the direction of the object relative to the moving body; a sound image direction determination unit of the warning sound control device determines a direction in which to localize a sound image of the warning sound based on a direction of the object relative to the moving body; a sound image trajectory determination unit of the warning sound control device determines a trajectory of a sound image of the warning sound based on a distance from the moving body to the object; an audio signal control unit of the warning sound control device controls the audio signal of the warning sound so that the sound image of the warning sound is localized in the direction determined by the sound image direction determination unit and so that the sound image of the warning sound moves along the trajectory determined by the sound image trajectory determination unit; the warning sound output processing unit of the warning sound control device outputs the audio signal of the warning sound controlled by the audio signal control unit from a speaker; In the warning sound control method, the sound image direction determination unit causes a direction in which the sound image of the warning sound is localized to follow a direction of the object relative to the moving body, the sound signal control unit changes a trajectory of a sound image of the warning sound in accordance with a distance from the moving body to the object. Warning sound control method.

Images