Information processing device, control method therefor, and program

Abstract

The present invention more effectively reduces discomfort of occupants, which is caused by a noise when the road surface condition switches.　An information processing device 10 comprises a control unit 11 for: acquiring audio information of a noise which is generated during traveling of a vehicle 50 and is sensed by a microphone 15; generating, on the basis of the acquired audio information, a cancellation sound for canceling a road noise caused by unevenness of a road surface G on which the vehicle 50 travels; and causing a speaker 16 to output the generated cancellation sound. The control unit 11: acquires road surface information indicating the condition of the road surface G in a direction in which the vehicle 50 advances; detects, on the basis of the acquired road surface information, a switching point at which the condition regarding the unevenness of the road surface G switches; and, in response to the detection of the switching point, causes the speaker 16 to output a noise sound obtained by imitating the road noise in a fixed transition section which is before or after the switching point passed along due to traveling by the vehicle 50 and in which the degree of unevenness of the road surface is smaller.

Description

Information processing device, control method thereof, and program

[0001] The present disclosure relates to an information processing device, a control method thereof, and a program.

[0002] It is known to output a cancellation sound to cancel out noise in order to reduce noise generated when a vehicle is traveling. For example, Patent Document 1 describes adjusting a cancellation sound to cancel road noise entering the vehicle cabin in accordance with the road surface conditions ahead of the vehicle.

[0003] Japanese Patent Application Laid-Open No. 2018-169525

[0004] However, the conventional configuration leaves room for improvement in terms of reducing the discomfort felt by occupants due to noise generated near the tires when road surface conditions change as the vehicle travels.

[0005] An object of the present disclosure is to more effectively reduce the discomfort felt by occupants due to noise when road surface conditions change.

[0006] (1) An information processing device according to one embodiment of the present disclosure includes a control unit that acquires audio information of noise generated while a vehicle is traveling, detected by a microphone; generates a cancellation sound based on the acquired audio information to cancel road noise caused by unevenness of the road surface on which the vehicle is traveling; and outputs the generated cancellation sound to a speaker. The control unit acquires road surface information indicating the condition of the road surface in the direction in which the vehicle is traveling; detects a change point where the condition related to unevenness of the road surface changes based on the acquired road surface information; and, in response to detecting the change point, outputs a noise sound simulating the road noise to the speaker in a certain transition section where the degree of unevenness of the road surface is smaller before or after the vehicle passes the change point as it travels.

[0007] (2) As an embodiment of the present disclosure, in (1), the control unit may reduce the volume of the cancellation sound output from the speaker or stop output of the cancellation sound during the transition period.

[0008] (3) As an embodiment of the present disclosure, in (1) or (2), when the control unit detects, based on the acquired road surface information, that the vehicle is traveling from a section where the road surface is less uneven to a section where the road surface is more uneven before or after the switching point, the control unit may cause the speaker to output the noise sound in the transition section before passing the switching point.

[0009] (4) As one embodiment of the present disclosure, in (3), the control unit may cause the speaker to output the noise at a louder volume as the vehicle approaches the switching point while traveling through the transition section.

[0010] (5) As an embodiment of the present disclosure, in any of (1) to (4), when the control unit detects, based on the acquired road surface information, that the vehicle is traveling from a section where the road surface is more uneven to a section where the road surface is less uneven before or after the switching point, the control unit may cause the speaker to output the noise sound in the transition section after passing the switching point.

[0011] (6) As an embodiment of the present disclosure, in (5), the control unit may cause the speaker to output the noise at a lower volume as the vehicle travels away from the switching point while traveling through the transition section.

[0012] (7) As one embodiment of the present disclosure, in any of (1) to (6), the control unit may acquire, as the road surface information, a photographed image of the road surface in the direction in which the vehicle is traveling, and analyze the photographed image to detect the change point at which the condition regarding the unevenness of the road surface changes.

[0013] (8) As an embodiment of the present disclosure, in any one of (1) to (7), the control unit may acquire the audio information detected by the microphone as the road surface information, and analyze the audio information to detect the change point at which the condition regarding the unevenness of the road surface changes.

[0014] (9) A control method for an information processing device according to one embodiment of the present disclosure is a control method for an information processing device including a control unit, wherein the control unit: acquires audio information of noise generated while the vehicle is traveling, detected by a microphone; generates a cancellation sound for canceling road noise caused by unevenness of the road surface on which the vehicle is traveling, based on the acquired audio information; and outputs the generated cancellation sound to a speaker, wherein the control unit: acquires road surface information indicating the condition of the road surface in the direction in which the vehicle is traveling; detects a switching point at which the condition related to unevenness of the road surface switches, based on the acquired road surface information; and, in response to detecting the switching point, outputs a noise sound simulating the road noise to the speaker in a certain transition section where the degree of unevenness of the road surface is smaller before or after the vehicle passes the switching point as it travels.

[0015] (10) A program according to an embodiment of the present disclosure causes a computer to operate as any one of the information processing devices (1) to (8).

[0016] According to an embodiment of the present disclosure, it is possible to more effectively reduce discomfort felt by occupants due to noise when road surface conditions change.

[0017] 1 is a diagram illustrating an example of a vehicle equipped with an information processing device according to an embodiment; FIG. 2 is a block diagram illustrating an example of the configuration of the information processing device; FIG. 3 is a flowchart illustrating an example of an operation procedure of the information processing device; FIG. 4 is a diagram illustrating an example of a change in the volume of road noise when passing through a switching point; FIG. 5 is a diagram illustrating an example of a change in the volume of road noise when passing through a switching point; FIG. 6 is a diagram illustrating an example of a change in the volume of road noise when passing through a switching point;

[0018] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, parts having the same configuration or function are denoted by the same reference numerals. In the description of this embodiment, duplicated descriptions of the same parts may be omitted or simplified as appropriate.

[0019] 1 is a diagram illustrating an example of a vehicle 50 equipped with an information processing device 10 according to an embodiment. The information processing device 10 outputs a cancellation sound for canceling noise generated when the vehicle 50 is traveling, thereby reducing noise inside the vehicle cabin.

[0020] The information processing device 10 includes a camera 14 , a microphone 15 , a speaker 16 , an acceleration sensor 17 , and a calculation unit 19 .

[0021] The camera 14 photographs the road surface G in the direction in which the vehicle 50 is traveling, and acquires a photographed image of the road surface G. The camera 14 is, for example, a stereo camera that acquires a three-dimensional image including depth information as a photographed image, but may also be an imaging device that acquires a two-dimensional image. The camera 14 may be equipped with two or more imaging elements to acquire a three-dimensional image. In the example of FIG. 1 , the camera 14 is provided in front of the vehicle 50 so as to be able to photograph the road surface G in front of the vehicle 50, but may also be provided at the rear of the vehicle 50.

[0022] The microphone 15 detects audio information of noise in the cabin of the vehicle 50. The microphone 15 may be provided, for example, near a seat in the vehicle 50. The information processing device 10 may invert the phase of the audio information of the noise detected by the microphone 15 to generate a cancellation sound to cancel the noise. In a state in which the cancellation sound is being output, the information processing device 10 may use the audio information in the cabin acquired by the microphone 15 to evaluate the effectiveness of noise canceling.

[0023] The speaker 16 outputs the cancellation sound as sound waves. The speaker 16 may be realized by an audio output device of an audio system originally provided in the vehicle 50. The speaker 16 may be installed at any location inside the vehicle. For example, the speaker 16 may be installed on or near the floor inside the vehicle.

[0024] The acceleration sensor 17 measures the acceleration of the vehicle 50. The measurement value of the acceleration sensor 17 is used to evaluate NVH (Noise, Vibration, and Harshness). The acceleration sensor 17 may be realized by any type of sensor, such as a semiconductor gauge, capacitance, or differential transformer type. The acceleration sensor 17 may be attached to an axle that transmits power generated by a drive unit, such as an engine, a motor, or a combination thereof, to the tires 51, 52.

[0025] The calculation unit 19 is connected to the camera 14, the microphone 15, the speaker 16, and the acceleration sensor 17, and controls the operations of these devices. As will be described later with reference to FIG. 2 , the calculation unit 19 includes a control unit 11, a storage unit 12, and a communication unit 13.

[0026] The vehicle 50 is, for example, a passenger car or the like, but is not limited to this and may be any vehicle. The vehicle may be, for example, a gasoline-powered vehicle, a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, or a battery-powered electric vehicle, but is not limited to these. The vehicle 50 has tires 51 and 52.

[0027] The tire 51 is provided with a communication device 53. The tire 52 is provided with a communication device 54.

[0028] The communication devices 53, 54 perform wireless communication. The communication devices 53, 54 are, for example, RF (Radio Frequency) tags. RF tags are also called RFID (Radio Frequency Identification) tags. The communication devices 53, 54 include an IC (Integrated Circuit) chip constituting a control unit and a memory unit, and one or more antennas connected to the IC chip. The IC chip may store any information related to the tires 51, 52, such as the tire's identification information, manufacturing date, circumference, and number of pitches per circumference. The pitches are widthwise grooves formed on the surface of the tires 51, 52. For example, the communication devices 53, 54 may have a longitudinal shape as a whole, with two antennas extending linearly, wavy, or spirally extending from the IC chip in opposite directions.

[0029] The IC chip may be operated by an induced electromotive force generated by electromagnetic waves received by one or more antennas. That is, the communication devices 53 and 54 may be passive communication devices. Alternatively, the communication devices 53 and 54 may further include a battery and be capable of communicating by generating electromagnetic waves using their own power. That is, the communication devices 53 and 54 may be active communication devices.

[0030] In the above configuration, the information processing device 10 acquires audio information of noise generated while the vehicle 50 is traveling using the microphone 15, generates a cancellation sound for canceling the road noise based on the audio information, and outputs the generated cancellation sound to the speaker 16. Road noise is noise caused by unevenness in the road surface G on which the vehicle 50 is traveling. The elastic motion of the tires 51, 52, which is excited by the unevenness in the road surface G, is transmitted through the suspension, vibrating the ceiling, floor, etc. of the vehicle body, resulting in interior noise.

[0031] Here, the information processing device 10 acquires road surface information indicating the condition of the road surface G in the direction in which the vehicle 50 is traveling. Based on the acquired road surface information, the information processing device 10 detects a switching point where the condition of the road surface G switches depending on its roughness. For example, a boundary between a paved road and an unpaved rough area corresponds to such a switching point. In response to detecting the switching point, the information processing device 10 causes the speaker 16 to output a noise sound simulating road noise in a certain transition section where the degree of roughness of the road surface G is smaller before or after the vehicle 50 passes through the switching point as it travels. For example, when the vehicle 50 moves from a good road with a small degree of roughness to a bad road with a large degree of roughness, the information processing device 10 causes the speaker 16 to output a noise sound simulating road noise in a transition section just before the switching point, which is the boundary between the good road and the bad road. Conversely, when the vehicle 50 moves from a bad road to a good road, the information processing device 10 outputs a noise sound simulating road noise from the speaker 16 in the transition section after passing the switching point.

[0032] In this way, the information processing device 10 reduces the change in noise inside the vehicle cabin perceived by the occupants before and after the switching point by deliberately outputting a noise sound simulating road noise from the speaker 16 in a certain transition section where the degree of unevenness is smaller before and after the vehicle 50 passes through the switching point. Therefore, even when the vehicle 50 passes through the switching point, the change in the volume of road noise due to changes in the road surface becomes gradual, making it possible to more effectively reduce the discomfort felt by the occupants due to the noise.

[0033] 2 is a block diagram showing an example configuration of the information processing device 10. As described above, the information processing device 10 includes a camera 14, a microphone 15, a speaker 16, an acceleration sensor 17, and a calculation unit 19. The calculation unit 19 includes a control unit 11, a storage unit 12, and a communication unit 13. The calculation unit 19 is one or more computer devices that can communicate with each other. The calculation unit 19 is not limited to these, and may be any general-purpose electronic device such as an FPGA (Field Programmable Gate Array), a single board computer (SBC), or a PC (Personal Computer), or may be another dedicated electronic device.

[0034] The control unit 11 includes one or more processors. In one embodiment, the "processor" may be, but is not limited to, a general-purpose processor or a dedicated processor specialized for a specific process. The control unit 11 is communicably connected to each component of the information processing device 10 and controls the operation of the information processing device 10 as a whole.

[0035] The storage unit 12 includes any storage module, such as a hard disk drive (HDD), a solid state drive (SSD), a read-only memory (ROM), and a random access memory (RAM). The storage unit 12 may function as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 12 stores any information used in the operation of the information processing device 10. For example, the storage unit 12 may store system programs, application programs, and various information received by the communication unit 13. The storage unit 12 is not limited to being built into the information processing device 10, but may also be an external database or an external storage module.

[0036] The communication unit 13 includes any communication module that can communicate with other devices such as a scanner using any communication technology. The communication unit 13 may further include a communication control module for controlling communication with other devices and a storage module for storing communication data such as identification information required for communication with other devices.

[0037] The functions of the information processing device 10 can be realized by executing a computer program (program) according to this embodiment on a processor included in the control unit 11. That is, the functions of the information processing device 10 can be realized by software. The computer program causes a computer to execute the processing of steps included in the operation of the information processing device 10, thereby causing the computer to realize the functions corresponding to the processing of each step. That is, the computer program is a program for causing a computer to function as the information processing device 10 according to this embodiment. The computer program may be recorded on a computer-readable recording medium. Programs include information used for processing by an electronic computer that is equivalent to a program. For example, data that is not a direct instruction to a computer but has properties that define computer processing falls under the category of "something equivalent to a program."

[0038] Some or all of the functions of the information processing device 10 may be realized by a dedicated circuit included in the control unit 11. That is, some or all of the functions of the information processing device 10 may be realized by hardware. Furthermore, the information processing device 10 may be realized by a single computer or by multiple computers working together.

[0039] 3 is a flowchart showing an example of an operation procedure of the information processing device 10. The operation of the information processing device 10 described with reference to FIG. 3 may correspond to one of the control methods of the information processing device 10. The operation of each step in FIG. 3 may be executed based on the control by the control unit 11 of the information processing device 10. The following processing is executed in parallel with the traveling of the vehicle 50.

[0040] In step S1 , the control unit 11 acquires audio information of noise detected by the microphone 15 and generated while the vehicle 50 is traveling.

[0041] In step S2, the control unit 11 analyzes the audio information acquired in step S1, and generates a cancellation sound for canceling road noise caused by the unevenness of the road surface G on which the vehicle 50 is traveling.

[0042] Specifically, the control unit 11 may generate a cancellation sound for canceling road noise based on the audio information detected by the microphone 15 and the acceleration of the vehicle 50 detected by the acceleration sensor 17. Specifically, the control unit 11 may predict the frequency band of the road noise based on the acceleration of the vehicle 50 detected by the acceleration sensor 17, and extract the road noise from the audio information detected by the microphone 15 based on the predicted frequency band, etc. The control unit 11 may invert the phase of the extracted road noise to generate a cancellation sound for the road noise.

[0043] In step S3, the control unit 11 causes the speaker 16 to output the cancellation sound generated in step S2.

[0044] In step S4, the control unit 11 acquires road surface information indicating the condition of the road surface G in the direction in which the vehicle 50 is traveling. The road surface information is any information indicating the condition of the road surface G on which the vehicle 50 is traveling, which may affect the noise reaching the vehicle cabin. For example, the road surface information may be, but is not limited to, a photographed image of the road surface G in the direction in which the vehicle 50 is traveling acquired by the camera 14, audio information detected by the microphone 15, or a combination thereof. For example, the road surface information may be information regarding the road surface G acquired by any sensor such as radar or LiDAR (Light Detection and Ranging). Alternatively, an external device such as a cloud or the storage unit 12 of the information processing device 10 may store in advance the road surface information indicating the condition of the road surface G in association with map information indicating the geographical position. The control unit 11 may use location information of the vehicle 50 measured by a device such as a GPS (Global Positioning System) receiver as a query and acquire road surface information corresponding to the location information from the external device or the storage unit 12.

[0045] In step S5, the control unit 11 determines whether there is a switching point where the condition of the road surface G changes based on the road surface information acquired in step S4. For example, the control unit 11 may determine the degree of unevenness of the road surface G based on the road surface information, and determine a point where the change in the degree of unevenness is greater than a certain threshold as a switching point. For example, the switching point may be located at the boundary between a good road with few or small unevennesses on the road surface G and a bad road with many or large unevennesses. When information acquired by the camera 14 is used as the road surface information, the control unit 11 may determine whether there is a switching point located a predetermined distance away from the vehicle 50. Alternatively, the control unit 11 may determine whether there is a switching point located at a location that takes a predetermined time to reach from the current location based on the speed and acceleration of the vehicle 50. The speed of the vehicle 50 can be acquired by any method. For example, the control unit 11 may calculate the speed of the vehicle 50 based on the acceleration of the vehicle 50 detected by the acceleration sensor 17. If a switching point exists (YES in step S5), the control unit 11 proceeds to step S6, and if not (NO in step S5), the control unit 11 proceeds to step S7.

[0046] In step S6, upon detecting the switching point, the control unit 11 causes the speaker 16 to output a noise sound simulating road noise in a certain transition section where the degree of unevenness of the road surface G is smaller before or after the vehicle 50 passes through the switching point as it travels.

[0047] The processing of steps S5 and S6 will be described with reference to Figures 4 to 7. Figures 4 to 7 are diagrams showing an example of changes in the volume of road noise when passing through a switching point. In Figures 4 to 7, the horizontal axis represents time, and the vertical axis represents the volume of road noise that has reached the passenger compartment of the vehicle 50.

[0048] 4 and 5 show changes in the volume of road noise reaching the vehicle cabin when the vehicle 50 moves from a good road to a bad road. In FIGS. 4 and 5, the vehicle 50 passes through a transition point where the road surface G changes from a good road to a bad road at time t1. FIG. 4 shows changes in road noise when step S6 is not performed. Graph 61 in FIG. 4 shows changes in road noise after the cancellation sound is output in step S3. As shown by graph 61 in FIG. 4, when step S6 is not performed, the volume of road noise reaching the vehicle cabin suddenly increases from V1 to V2 at the transition point. Such a sudden change in noise volume is perceived as unpleasant noise by the occupants. Therefore, in order to mitigate such a sudden change in noise volume, the control unit 11 controls the speaker 16 to output a noise sound simulating road noise in the transition section just before the transition point.

[0049] FIG. 5 shows the change in road noise when processing step S6 is performed. In the example of FIG. 5, a noise sound simulating road noise is output during the transition section from time t0 to time t1. Area 62 shows the volume of this intentionally added noise. As a result, as shown in graph 63, the volume of road noise reaching the vehicle cabin increases gradually during the transition section, making it possible to reduce discomfort to the occupants.

[0050] The control unit 11 may perform similar processing when the vehicle 50 moves from a bad road to a good road. FIGS. 6 and 7 show changes in the volume of road noise reaching the vehicle cabin when the vehicle 50 moves from a bad road to a good road. In FIGS. 6 and 7 , the vehicle 50 passes through a transition point where the road surface G changes from a bad road to a good road at time t1. FIG. 6 shows changes in road noise when the processing of step S6 is not performed. Graph 64 in FIG. 6 shows changes in road noise after the cancellation sound is output in step S3. As shown by graph 64 in FIG. 6 , when the processing of step S6 is not performed, the volume of road noise reaching the vehicle cabin suddenly decreases from V2 to V1 at the transition point. Even when the noise decreases, such a sudden change in noise volume is perceived as unpleasant by the occupants. Therefore, in order to mitigate such a sudden change in the volume of the noise, the control unit 11 causes the speaker 16 to output a noise sound that imitates road noise in the transition section after passing through the switching point.

[0051] FIG. 7 shows the change in road noise when processing step S6 is performed. In the example of FIG. 7, a noise simulating road noise is output during the transition period from time t1 to time t2. Area 65 shows the volume of this intentionally added noise. As a result, as shown in graph 66, the volume of road noise reaching the vehicle cabin gradually decreases during the transition period, making it possible to reduce discomfort to the occupants.

[0052] In step S7, the control unit 11 determines whether or not to end the processing of the flowchart. For example, the control unit 11 may determine to end the processing when the engine of the vehicle 50 is turned off, when an occupant issues an instruction to end the processing, etc. If the processing is to be ended (YES in step S7), the control unit 11 ends the processing of the flowchart, and if not (NO in step S7), the control unit 11 returns to step S1 to continue the processing.

[0053] As described above, the information processing device 10 intentionally outputs a noise sound simulating road noise from the speaker 16 in a certain transition section where the degree of unevenness is smaller before or after the vehicle 50 passes through a switching point. Therefore, even when passing through a switching point, the change in noise due to changes in the road surface becomes gradual, making it possible to more effectively reduce the discomfort felt by the occupants due to the noise.

[0054] In addition, while the vehicle is traveling in the transition section, the information processing device 10 may reduce the volume of the cancellation sound output from the speaker 16 or may stop output of the cancellation sound in step S3. This type of processing makes it possible to reduce the discomfort felt by occupants due to noise, even if a noise simulating road noise is not output from the speaker 16.

[0055] Furthermore, as described with reference to Figures 5 and 7, the information processing device 10 may increase the volume of the noise sound that simulates road noise in the transition section when traveling in a location closer to the switching point.

[0056] For example, when the information processing device 10 detects that the vehicle 50 is traveling from a good road, where the degree of roughness of the road surface G is smaller, to a bad road, where the degree of roughness is larger, before and after the switching point, the information processing device 10 may cause the speaker 16 to output noise in a transition section before passing the switching point. With this configuration, when the vehicle is traveling from a good road to a bad road, noise is intentionally output while traveling in the transition section before the switching point, thereby reducing the change in noise before and after passing the switching point. Therefore, the change in noise before and after passing the switching point becomes gradual, making it possible to more effectively reduce the discomfort of the occupants caused by noise.

[0057] Specifically, when moving from a good road to a bad road, the information processing device 10 may cause the speaker 16 to output noise at a volume that increases as the vehicle 50 approaches the switching point while traveling through the transition section. With this configuration, by changing the volume of the noise output while traveling through the transition section depending on the distance from the switching point, the change in noise perceived by the occupants can be made smaller, and the discomfort felt by the occupants can be further reduced effectively.

[0058] Furthermore, when the information processing device 10 detects that the vehicle 50 is traveling from a bad road to a good road before or after a switching point, the information processing device 10 may cause the speaker 16 to output noise in the transition section after passing the switching point. With this configuration, when the vehicle is traveling from a bad road to a good road, noise is intentionally output while traveling in the transition section after passing the switching point, thereby reducing the change in noise before and after passing the switching point. Therefore, the change in noise before and after passing the switching point becomes gradual, making it possible to more effectively reduce the discomfort of the occupants caused by noise.

[0059] Specifically, when moving from a bad road to a good road, the information processing device 10 may cause the speaker 16 to output noise at a lower volume as the vehicle 50 travels through the transition section and moves away from the switching point. With this configuration, by changing the volume of the noise output while traveling through the transition section depending on the distance from the switching point, the change in noise perceived by the occupants can be made smaller, and the discomfort felt by the occupants can be further reduced effectively.

[0060] In this way, by changing the volume of the noise output while traveling through the transition section depending on the distance from the switching point, the information processing device 10 can further reduce the change in noise perceived by the occupant, thereby more effectively reducing the occupant's discomfort. However, the information processing device 10 may simplify the processing so that the volume of the noise does not change continuously. For example, the information processing device 10 may output noise at a constant volume from the speaker 16 during the transition section. Alternatively, the information processing device 10 may select one of a plurality of predetermined volume levels and switch the volume level as appropriate while traveling through the transition section to output the noise from the speaker 16.

[0061] Furthermore, the information processing device 10 may acquire, as road surface information, an image of the road surface G in the traveling direction of the vehicle 50 taken by the camera 14, analyze the image, and detect a change point where the condition related to the unevenness of the road surface G changes. In this way, since the condition of the road surface G is detected based on the image of the road surface G along which the vehicle 50 will travel, it is possible to accurately determine the timing of passing through the change point and effectively perform processing to reduce discomfort to the occupants with little time lag.

[0062] Furthermore, the information processing device 10 may acquire audio information detected by the microphone 15 as road surface information, analyze the audio information, and detect a change point where the condition of the road surface G changes from uneven to uneven. For example, the information processing device 10 may detect the passage of a change point where a bad road changes to a good road from the audio information, and output a noise sound from the speaker 16 in response to the detection of the passage of the change point. In this way, since the change point is detected based on the audio information of the microphone 15 used for noise canceling, it is possible to perform processing to reduce discomfort to the occupants without providing any additional equipment.

[0063] The present disclosure is not limited to the above-described embodiments. For example, multiple blocks shown in the block diagram may be integrated, or one block may be divided. Multiple steps shown in the flowchart may be executed in parallel or in a different order depending on the processing capacity of the device executing each step, or as needed, instead of being executed in chronological order as described. Other modifications are possible within the scope of the present disclosure. [Contribution to the United Nations-led Sustainable Development Goals (SDGs)]

[0064] The SDGs have been proposed to realize a sustainable society. One embodiment of the present invention is thought to be a technology that can contribute to "No. 9 - Building a foundation for industry and technological innovation."

[0065] REFERENCE SIGNS LIST 10 Information processing device 11 Control unit 12 Memory unit 13 Communication unit 14 Camera 15 Microphone 16 Speaker 17 Acceleration sensor 19 Calculation unit 50 Vehicle 51, 52 Tires 53, 54 Communication device 61 to 66 Graph G Road surface

Claims

1. An information processing device comprising: a control unit that acquires audio information of noise generated while a vehicle is traveling, detected by a microphone; generates a cancellation sound to cancel road noise caused by unevenness of the road surface on which the vehicle is traveling based on the acquired audio information; and outputs the generated cancellation sound to a speaker, wherein the control unit acquires road surface information indicating the condition of the road surface in the direction in which the vehicle is traveling; detects a switching point where the condition related to unevenness of the road surface switches based on the acquired road surface information; and, in response to detecting the switching point, outputs a noise sound simulating the road noise to the speaker in a certain transition section where the degree of unevenness of the road surface is smaller before or after the vehicle passes the switching point as it travels.

2. The information processing device according to claim 1, wherein the control unit reduces the volume of the cancellation sound output from the speaker or stops output of the cancellation sound during the transition period.

3. The information processing device of claim 1, wherein when the control unit detects, based on the acquired road surface information, that the vehicle is traveling from a section where the road surface is less uneven to a section where the road surface is more uneven before or after the switching point, the control unit causes the speaker to output the noise sound in the transition section before passing the switching point.

4. The information processing device according to claim 3, wherein the control unit causes the speaker to output the noise at a louder volume as the vehicle approaches the switching point while traveling through the transition section.

5. The information processing device of claim 1, wherein when the control unit detects, based on the acquired road surface information, that the vehicle is traveling from a section where the road surface is more uneven to a section where the road surface is less uneven before or after the switching point, the control unit causes the speaker to output the noise sound in the transition section after passing the switching point.

6. The information processing device according to claim 5, wherein the control unit causes the speaker to output the noise at a lower volume as the vehicle travels away from the switching point while the vehicle is traveling in the transition section.

7. The information processing device according to claim 1, wherein the control unit acquires, as the road surface information, photographed images of the road surface in the direction in which the vehicle is traveling, and analyzes the photographed images to detect the change point at which the condition regarding the unevenness of the road surface changes.

8. The information processing device according to claim 1, wherein the control unit acquires the audio information detected by the microphone as the road surface information, analyzes the audio information, and detects the change point at which the condition regarding the unevenness of the road surface changes.

9. A control method for an information processing device having a control unit, comprising the steps of: acquiring audio information of noise generated while the vehicle is traveling, detected by a microphone; generating a cancellation sound for canceling road noise caused by unevenness of the road surface on which the vehicle is traveling, based on the acquired audio information; and outputting the generated cancellation sound from a speaker, wherein the control unit acquires road surface information indicating the condition of the road surface in the direction in which the vehicle is traveling; detects a switching point where the condition related to unevenness of the road surface switches, based on the acquired road surface information; and, in response to detecting the switching point, causes the speaker to output a noise sound simulating the road noise in a certain transition section where the degree of unevenness of the road surface is smaller before or after the vehicle passes the switching point as it travels.

10. A program for causing a computer to operate as an information processing device according to any one of claims 1 to 8.

Images