Vehicle sound generator

Abstract

To provide a vehicle sound generator that can improve driver comfort. [Solution] The vehicle sound generator (3, 3A) comprises a sound detection unit (33) and output units (34, 34a, 34b). The sound detection unit (33) detects vehicle sounds generated by the movement of the vehicle (100, 100A). The output units (34, 34a, 34b) output an adjusted sound based on first data relating to the vehicle sound and second data relating to a reference sound corresponding to the driver's perception.

Description

Technical Field

[0001] The present invention relates to a vehicle sound generating device mounted on a vehicle.

Background Art

[0002] Conventionally, noise canceling devices for suppressing or removing noise around a vehicle have been proposed. For example, Patent Document 1 discloses a noise canceling device that suppresses or removes noise by radiating a sound having a phase opposite to that of the noise into the vehicle interior through a speaker.

[0003] Also, conventionally, a vehicle effect sound generating device that detects an acceleration / deceleration operation by a driver and generates an effect sound corresponding to the amount of acceleration / deceleration in the vehicle interior has been proposed. For example, Patent Document 2 discloses a pseudo sound generating device that generates an effect sound corresponding to the acceleration / deceleration and engine speed of a vehicle from a speaker.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, continuously variable transmissions (CVTs), which continuously change the gear ratio to optimize the rotational speed of the engine or motor, have become widespread, for example, as transmissions for vehicles. In CVTs, a discrepancy between the amount the driver presses the accelerator and the actual acceleration of the vehicle is a problem, resulting in a rubber band feeling that drivers find unpleasant. Patent documents 1 and 2 generate noise cancellation and sound effects according to the state or movement of the vehicle, such as engine speed. However, in vehicles equipped with a CVT and an engine, or vehicles equipped with a power source other than an engine, such as a motor, there is a discrepancy between the state or movement of the vehicle and the driver's perception, so the driver's discomfort cannot be eliminated.

[0006] The present invention is based on the above-mentioned problems and aims to provide a vehicle sound generating device that can improve driver comfort. [Means for solving the problem]

[0007] The vehicle sound generating device according to the present invention comprises a sound detection unit that detects vehicle sounds generated by the movement of a vehicle, and an output unit that outputs an adjusted sound based on first data relating to the vehicle sound and second data relating to a reference sound corresponding to the driver's perception. [Effects of the Invention]

[0008] According to the vehicle sound generating device of the present invention, driver comfort can be improved by outputting an adjusted sound based on second data relating to a reference sound that corresponds to the driver's perception. [Brief explanation of the drawing]

[0009] [Figure 1] This figure illustrates the schematic configuration of a vehicle equipped with a vehicle sound generating device according to Embodiment 1. [Figure 2] This figure illustrates the sound generation process by a vehicle sound generator according to Embodiment 1. [Figure 3] This is a flowchart illustrating the flow of sound generation processing in Embodiment 1. [Figure 4] This figure illustrates a schematic configuration of a vehicle equipped with a vehicle sound generating device according to Embodiment 2. [Figure 5] This is a flowchart illustrating the flow of sound generation processing in Embodiment 2. [Figure 6] This is a flowchart illustrating the sound generation process in Embodiment 3. [Modes for carrying out the invention]

[0010] An example of a vehicle sound generating device according to the present invention will be described below with reference to the drawings.

[0011] Embodiment 1. Figure 1 is a diagram illustrating the schematic configuration of a vehicle 100 equipped with a vehicle sound generator 3 according to Embodiment 1. As shown in Figure 1, the vehicle 100 of this embodiment is equipped with a drive unit 1, a vehicle speed detection device 2, and a vehicle sound generator 3. The drive unit 1, the vehicle speed detection device 2, and the vehicle sound generator 3 are connected to each other via wired or wireless communication for data communication. Note that Figure 1 only shows the components of the vehicle 100 that are relevant to the present invention. In addition to the components shown in Figure 1, the vehicle 100 is equipped with equipment and devices that are naturally present in a typical vehicle.

[0012] The drive unit 1 is a powertrain that transmits power to the drive wheels of the vehicle 100. In Figure 1, only the engine 11 is shown as an example of the components of the drive unit 1 that are relevant to the present invention. However, the drive unit 1 may also include other power transmission devices such as a transmission, clutch, or drive shaft in addition to the components shown in Figure 1. In addition, an electric motor may be provided in place of the engine 11, or together with the engine 11, in the drive unit 1. The following explanation will use the case in which the drive unit 1 is equipped with an engine 11 as an example.

[0013] The engine 11 supplies the driving force to rotate the drive wheels of the vehicle 100. For example, the engine 11 is a gasoline engine or a diesel engine and is coupled with a continuously variable transmission (CVT). The rotational speed of the engine 11 is transmitted to the vehicle sound generator 3. If the drive unit 1 includes an electric motor and the electric motor is operating, the rotational speed of the electric motor may be transmitted to the vehicle sound generator 3 instead of, or together with, the rotational speed of the engine 11.

[0014] The vehicle speed detection device 2 detects the driving speed of the vehicle 100 (hereinafter referred to as "vehicle speed"). The vehicle speed detection device 2 consists of, for example, a sensor that reads the rotational speed of the drive wheels of the vehicle 100, and a computer that calculates the vehicle speed from the read rotational speed of the drive wheels and the size of the drive wheels. The vehicle speed detected by the vehicle speed detection device 2 is transmitted to the vehicle sound generator 3.

[0015] The vehicle sound generator 3 is a device for providing sounds in the vehicle cabin of the vehicle 100 that correspond to the driver's perception. More specifically, the vehicle sound generator 3 generates an adjustment sound that cancels and / or supplements the actual vehicle sound, thereby allowing the driver to perceive a sound that corresponds to their perception (hereinafter referred to as the "reference sound") and reducing driver discomfort. As shown in Figure 1, the vehicle sound generator 3 of this embodiment includes a control unit 31, a storage unit 32, a microphone 33, and a speaker 34.

[0016] The control unit 31 consists of a processor such as a CPU that executes a program stored in the storage unit 32, a dedicated processing circuit such as an ASIC or FPGA, or both. The control unit 31 includes a vehicle sound detection unit 311, a comparison unit 312, and a data generation unit 313. The vehicle sound detection unit 311, the comparison unit 312, and the data generation unit 313 are functional units that are realized by the processor constituting the control unit 31 executing a program stored in the storage unit 32, or by a dedicated processing circuit.

[0017] The vehicle sound detection unit 311 detects vehicle sounds that are generated by the running of the vehicle 100. The vehicle sound detection unit 311 estimates engine sounds included in the vehicle sounds based on the rotational speed of the engine 11. Further, the vehicle sound detection unit 311 detects the overall vehicle sound in the vehicle 100 using the sound collected by the microphone 33 as feedback. When the drive device 1 has an electric motor and the vehicle 100 runs only by driving the electric motor, the vehicle sound detection unit 311 estimates motor sounds included in the vehicle sounds based on the rotational speed of the electric motor, and in the same manner as in the case of engine sounds, detects the overall vehicle sound in the vehicle 100 using the sound collected by the microphone 33 as feedback. Alternatively, when the drive device 1 has an engine and an electric motor and the vehicle 100 runs by driving both the engine and the electric motor, the vehicle sound detection unit 311 estimates engine sounds included in the vehicle sounds based on the rotational speed of the engine 11, estimates motor sounds included in the vehicle sounds based on the rotational speed of the electric motor, and detects the overall vehicle sound in the vehicle 100 using the sound collected by the microphone 33 as feedback. The vehicle sound detection unit 311 outputs first data regarding the detected vehicle sound to the comparison unit 312. When sounds other than engine sounds and motor sounds, such as wind noise or road noise, etc., which cannot be estimated from the rotational speed of the engine 11 or the electric motor, occur, the sound collected by the microphone 33 may be used as the overall vehicle sound, and first data regarding the vehicle sound may be output from the microphone 33 to the comparison unit 312. At least one of the vehicle sound detection unit 311 and the microphone 33 in the present embodiment corresponds to the sound detection unit of the present invention.

[0018] The comparison unit 312 compares the first data regarding the vehicle sound detected by the vehicle speed detection device 2 with the second data regarding the reference sound stored in the storage unit 32 according to the vehicle speed detected by the vehicle speed detection device 2, and outputs the comparison result to the data generation unit 313. The first data includes elements of the vehicle sound, and the second data includes elements of the reference sound. The elements of each sound are at least any one of sound pressure, pitch, and timbre. The comparison unit 312, as an example, compares at least any one of the sound pressure, pitch, and timbre of the vehicle sound at the current vehicle speed with at least any one of the sound pressure, pitch, and timbre of the reference sound at the vehicle speed, and transmits to the data generation unit 313 as the comparison result whether the vehicle sound and the reference sound are the same. When the sound pressure of the vehicle sound is different from the sound pressure of the reference sound, when the pitch of the vehicle sound is different from the pitch of the reference sound, and when the timbre of the vehicle sound is different from the timbre of the reference sound, the comparison unit 312 transmits to the data generation unit 313 a comparison result that the vehicle sound and the reference sound are not the same. Here, the so-called "same" includes not only the case of being exactly the same, but also the case within a preset allowable range even if it is not exactly the same.

[0019] The data generation unit 313 generates data corresponding to the adjustment sound output from the speaker 34 according to the comparison result of the comparison unit 312. Specifically, when it is determined that the vehicle sound is different from the reference sound, the data generation unit 313 generates cancellation data for canceling the vehicle sound and pseudo data corresponding to the reference sound, and superimposes these to generate adjustment data corresponding to the adjustment sound. The cancellation data and the pseudo data are data regarding sound waves including information regarding each of sound pressure, pitch, and timbre which are elements of sound. The pseudo data is generated such that the sound elements are the same as the second data of the reference sound. The processing of the data generation unit 313 will be described in detail later.

[0020] The memory unit 32 is composed of, for example, volatile or non-volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), or flash memory. The memory unit 32 stores a program for the control unit 31 to execute sound generation processing, and various data such as calculation formulas and thresholds used in the execution of the program. The memory unit 32 also stores second data related to a reference tone, which is a sound corresponding to the driver's perception.

[0021] The microphone 33 is located inside the vehicle 100 and collects sound from inside the vehicle, processes the signal, and transmits it to the control unit 31. There may be one microphone 33 or multiple microphones.

[0022] Speaker 34 is an output unit located inside the vehicle 100 that outputs adjustment sounds. Speaker 34 outputs adjustment sounds based on adjustment data generated by the control unit 31. Although only one speaker 34 is shown in Figure 1, there may be multiple speakers 34. If there are multiple speakers 34, adjustment sounds based on adjustment data generated by the control unit 31 will be output from each of the multiple speakers 34.

[0023] Figure 2 is a diagram illustrating the sound generation process by the vehicle sound generator 3 according to Embodiment 1. The vertical axis of Figure 2 represents the sound elements (sound pressure, pitch, or timbre) SE, and the horizontal axis represents the sensory parameter X. In Figure 2, the graph of the reference sound Ds is shown as a solid line, and the graph of the vehicle sound Dv is shown as a dashed line. Note that Figure 2 schematically shows the graphs of each sound to explain the sound generation process, and the shape of the graphs of each sound is not limited to the example in Figure 2.

[0024] If the vehicle 100 is equipped with a continuously variable transmission (CVT) that can continuously change the gear ratio, a discrepancy may occur between the amount the driver presses the accelerator and the actual acceleration of the vehicle 100, resulting in a rubber-band feeling that the driver finds unpleasant. Furthermore, even without a CVT, depending on the vehicle's power source and the environment in which the vehicle is located, sounds that are incompatible with the driver's perception may be generated, causing driver discomfort. In response to this, the vehicle sound generator 3 of this embodiment suppresses the discrepancy between the state or movement of the vehicle 100 and the driver's perception by adjusting the vehicle sound using a reference tone Ds that corresponds to the driver's perception.

[0025] The sensory parameter X is an index that reflects the driver's perception. As shown in Figure 2, the reference tone Ds is determined according to the sensory parameter X and is the ideal sound where the sensory parameter X and the driver's perception match. Second data regarding the reference tone Ds is generated in advance through experimental verification and stored in the memory unit 32. In Figure 2, an example is shown in which the reference tone Ds changes linearly according to the sensory parameter X, but the reference tone Ds is not limited to changing linearly according to the sensory parameter X.

[0026] The sensory parameter X is at least one of the following: vehicle speed, accelerator pedal depression amount, brake pedal depression amount, vibration of vehicle 100, information from a camera mounted on vehicle 100, steering angle information (steering wheel angle), outside temperature of vehicle 100 (outside air temperature), inside temperature of vehicle 100 (cabin temperature), time of day, and weather information. Vehicle speed is detected by the vehicle speed detection device 2. For example, the reference tone Ds is set so that the pitch becomes higher or the sound pressure increases as the vehicle speed increases. The accelerator pedal depression amount is detected by a sensor installed in vehicle 100 that detects changes in the position of the accelerator pedal. For example, the reference tone Ds is set so that the sound pressure increases as the accelerator pedal depression amount increases. The brake pedal depression amount is detected by a sensor installed in vehicle 100 that detects changes in the position of the brake pedal. For example, the reference tone Ds is set so that the sound pressure decreases as the brake pedal depression amount increases. The vibrations of the vehicle 100 are detected by an acceleration sensor or the like installed in the vehicle 100. For example, the reference sound Ds is set so that the sound pressure increases as the vibration of the vehicle 100 increases.

[0027] The information from the video footage of the camera mounted on vehicle 100 consists of at least one of the following: video footage of the outside of vehicle 100 and video footage of the inside of vehicle 100. The video footage of the outside of vehicle 100 is, for example, information regarding the brightness outside of vehicle 100. The brightness outside of vehicle 100 is obtained from the brightness of the video footage from the camera mounted on vehicle 100. For example, in situations surrounded by obstacles such as inside a tunnel, it is difficult to see far ahead, making the speed seem higher. Furthermore, vehicle sound reflects off the inner walls of the tunnel and is transmitted into the vehicle, creating a superimposed sound that makes the vehicle sound seem louder. As a result, the driver may mistakenly perceive the speed of vehicle 100 as high inside the tunnel, and may drive at a lower speed than the actual speed, potentially causing congestion inside the tunnel. Therefore, as an example, when vehicle 100 enters a tunnel, the reference sound Ds when the external brightness is below a threshold brightness is set to correspond to the actual vehicle speed. In this case, the sensory parameter X is the video footage from the camera and the vehicle speed. As another example, the sound pressure of the reference tone Ds when the brightness outside the vehicle 100 is below a threshold brightness is set to be lower than the sound pressure of the reference tone Ds when the brightness is higher than the threshold brightness. Here, the threshold brightness is specifically a brightness lower than the brightness due to sunlight, for example, the brightness inside a tunnel, or the brightness between the brightness due to sunlight and the brightness inside a tunnel. In addition, changes in the brightness outside the vehicle 100 may be detected using an illuminometer or the like installed outside the vehicle 100, along with or instead of the image of the outside of the vehicle 100.

[0028] Furthermore, the information from the external video of vehicle 100 may also be information about the location (scenery) where vehicle 100 is traveling. Information about the location where vehicle 100 is traveling can be obtained by using AI (Artificial Intelligence) to perform image recognition on the external video of vehicle 100 captured by a camera. For example, the sounds desired by the driver will differ depending on whether vehicle 100 is traveling on a highway, in a rural area, along the coast, or in an urban area. Therefore, as an example, a reference sound Ds can be set according to the location where vehicle 100 is traveling. In this case, the sounds preferred by drivers in each location can be determined through experiments, etc., and stored in a database as reference sounds Ds. In addition, information about the location where vehicle 100 is traveling may be obtained using GPS information installed in vehicle 100, along with, or instead of, the internal video of vehicle 100.

[0029] The video information from inside vehicle 100 includes, for example, information about the driver's psychological state inside vehicle 100. Information about the driver's psychological state can be obtained by using AI-based image recognition on video footage of the inside of vehicle 100 captured by a camera. In this case, the relationship between the driver's movements or facial expressions, which are information about the driver's psychological state, and the preferred type of reference sound Ds is pre-programmed into a database through AI learning. For example, when the driver has an irritated expression, that is, when the driver is angry, the sound pressure of the reference sound Ds is set higher than when the driver is not angry. When a driver is angry, they tend to increase their speed, so by increasing the sound pressure even at low vehicle speeds, it is possible to make the driver feel like they are driving fast. This can suppress the driver from increasing their speed and ensure safety.

[0030] Steering angle information is detected by a steering angle sensor installed on the vehicle 100, which measures the angle of the steering wheel. Reference sound Ds based on steering angle information are also determined in advance through experiments and other means, and stored in a database, based on sounds preferred by drivers. For example, in the case of a driver who prefers to drive at high speeds, the reference sound Ds may be set to output a drift sound (the sound of tires rubbing against the road surface) when cornering (when the steering wheel angle exceeds a predetermined angle). Alternatively, to prevent accidents when cornering, the reference sound Ds may be set so that the sound pressure increases as the steering wheel angle increases. Furthermore, in the case of a driver who prefers safe driving or a quiet environment, the reference sound Ds may be set so that the sound pressure decreases as the steering wheel angle increases.

[0031] The ambient temperature, which is the temperature outside the vehicle 100, is detected by a temperature sensor installed on the outside of the vehicle 100. For example, when the ambient temperature is high, such as in summer, there is a tendency to want to rev the engine compared to when the ambient temperature is low, such as in winter. Therefore, as an example, when the ambient temperature is high, the sound pressure of the reference tone Ds is set higher than when the ambient temperature is low. The cabin temperature, which is the temperature inside the vehicle 100, is detected by a temperature sensor installed inside the cabin of the vehicle 100. As an example, when the cabin temperature is high, the sound pressure of the reference tone Ds is set higher than when the cabin temperature is low.

[0032] Information regarding the time of day is obtained from a clock installed in vehicle 100. When it is nighttime, sound travels more easily due to factors such as atmospheric pressure. Therefore, as an example, when it is nighttime, the sound pressure of the reference tone Ds is set lower than when it is daytime. Information regarding the weather is obtained from images from a camera mounted on vehicle 100 or through communication with an external device that manages weather information. When it is raining, sound travels less easily. Therefore, as an example, when it is raining, the sound pressure of the reference tone Ds is set higher than when it is sunny.

[0033] Furthermore, the sensory parameter X may be a combination of two or more of the following: vehicle speed, accelerator pedal depression, brake pedal depression, vibration of vehicle 100, information from a camera mounted on vehicle 100, steering angle information (steering wheel angle), outside temperature of vehicle 100 (outside air temperature), inside temperature of vehicle 100 (cabin temperature), time of day, and weather. For example, the sensory parameter X may be a combination of the brightness outside vehicle 100, which is information from a camera mounted on vehicle 100, and the vehicle speed. In this case, as an example, as described above, if the brightness outside vehicle 100 drops sharply to below a threshold brightness, such as when entering a tunnel, the sound pressure of the reference sound Ds will be set lower even at the same vehicle speed. Alternatively, the sensory parameter X may be a combination of the brightness outside vehicle 100, which is information from a camera mounted on vehicle 100, and the time of day. In this case, if the time of day is daytime and the brightness is below a threshold brightness, it is estimated that the vehicle has entered a tunnel, and the sound pressure of the reference sound Ds will be set lower. In addition to the above, a reference tone Ds can be set for any combination.

[0034] For example, if the sensory parameter X is vehicle speed, the comparison unit 312 compares the elements of the vehicle sound Dv at the current vehicle speed detected by the vehicle speed detection device 2 with the elements of the reference sound Ds at that vehicle speed. Then, it outputs to the data generation unit 313 as a comparison result whether or not the vehicle sound Dv and the reference sound Ds are the same. In the example in Figure 2, the sensory parameter X (vehicle speed) is X V1 In this case, it is determined that the vehicle sound Dv and the reference sound Ds are not the same, and the sensory parameter X (vehicle speed) is X V2 In this case, it is determined that the vehicle sound Dv and the reference sound Ds are the same. If the comparison unit 312 determines that the vehicle sound Dv and the reference sound Ds are not the same, the data generation unit 313 generates adjustment data corresponding to an adjustment sound that makes the vehicle sound Dv the reference sound Ds, and outputs the adjustment sound from the speaker 34.

[0035] Figure 3 is a flowchart illustrating the flow of sound generation processing in Embodiment 1. Figure 3 explains the flow of sound generation processing when the sensory parameter X is vehicle speed as an example. As shown in Figure 3, first in step S1, the vehicle sound detection unit 311 detects the vehicle sound. The vehicle sound detection unit 311 generates first data related to the vehicle sound based on the rotational speed of the engine 11 and the signal from the microphone 33, and transmits it to the comparison unit 312. Also, in step S2, the vehicle speed of the vehicle 100 is detected by the vehicle speed detection device 2. The vehicle speed detected by the vehicle speed detection device 2 is transmitted to the comparison unit 312.

[0036] Then, in step S3, the comparison unit 312 compares the first data relating to the detected vehicle sound with the second data relating to the reference sound stored in the memory unit 32 at the detected vehicle speed, and determines whether the vehicle sound and the reference sound are the same. If the comparison result shows that the vehicle sound and the reference sound are the same (S3: YES), the process returns to step S1. In other words, if the vehicle sound and the reference sound are the same, there is no need to cancel or supplement the vehicle sound, and therefore no adjustment sound is generated from the vehicle sound generator 3.

[0037] If the vehicle sound and the reference sound are not the same (S3:NO), in step S4, the data generation unit 313 generates cancellation data to cancel the vehicle sound Dv. Here, the data generation unit 313 generates cancellation data with the opposite phase to the vehicle sound Dv using a known method as active noise cancellation.

[0038] Then, in step S5, the data generation unit 313 generates pseudo-data corresponding to the reference tone Ds. Here, the data generation unit 313 generates pseudo-data that includes the same elements as the second data of the reference tone Ds using a known method as active sound control. More specifically, the data generation unit 313 refers to the second data of the reference tone Ds stored in the storage unit 32 and generates pseudo-data that includes elements of the reference tone Ds corresponding to the current vehicle speed detected by the vehicle speed detection device 2. Note that the order of the processing in step S4 and step S5 may be reversed, or the processing in step S4 and step S5 may be performed in parallel.

[0039] In step S6, the data generation unit 313 superimposes the cancellation data and pseudo-data to generate adjustment data corresponding to the adjustment sound. Then, in step S7, the adjustment data generated by the data generation unit 313 is output to the speaker 34, and the adjustment sound corresponding to the adjustment data is output from the speaker 34. As a result, vehicle noises (such as the booming sound of the engine 11) generated in the cabin are canceled, and a sound corresponding to the reference sound Ds is generated in the cabin, which is perceived by the driver as a sound according to their senses.

[0040] As described above, the vehicle sound generator 3 of this embodiment stores a reference sound corresponding to the driver's perception in advance and generates an adjustment sound to adjust the vehicle sound to match the reference sound. As a result, the driver can perceive sounds that match their own perception while the vehicle 100 is in motion, improving comfort.

[0041] In particular, the vehicle sound generator 3 generates sound according to an indicator (such as vehicle speed) that reflects the driver's perception, regardless of the engine speed of the engine 11. This makes it possible, for example, to control the gear ratio using a CVT to prioritize the efficiency of the engine 11, thereby further improving the efficiency of the engine 11, while reducing discomfort caused by the discrepancy between the state of the vehicle 100 and the driver's perception, such as a rubber band feeling.

[0042] Embodiment 2. Embodiment 2 will now be described. The vehicle sound generator 3A of Embodiment 2 differs from that of Embodiment 1 in its method of outputting the adjusted sound. Figure 4 is a diagram illustrating the schematic configuration of a vehicle 100A equipped with the vehicle sound generator 3A according to Embodiment 2. As shown in Figure 4, the vehicle 100A of this embodiment is equipped with a drive unit 1, a vehicle speed detection device 2, and a vehicle sound generator 3A. The configurations of the drive unit 1 and the vehicle speed detection device 2 are the same as those of Embodiment 1.

[0043] The vehicle sound generator 3A of this embodiment includes a control unit 31, a storage unit 32, a microphone 33, a first speaker 34a, and a second speaker 34b. The configuration of the storage unit 32 and the microphone 33 of this embodiment is the same as that of Embodiment 1. The control unit 31 of this embodiment differs from Embodiment 1 in that it outputs the cancellation data and pseudo-data generated by the data generation unit 313 to the first speaker 34a and the second speaker 34b, respectively.

[0044] The first speaker 34a and the second speaker 34b are output units located inside the vehicle 100A that output adjustment sounds. The first speaker 34a outputs a sound based on cancellation data generated by the control unit 31. The second speaker 34b outputs a sound based on pseudo-data generated by the control unit 31. In this embodiment, the sound output from the first speaker 34a and the sound output from the second speaker 34b are collectively referred to as the "adjustment sound". The number of first speakers 34a and second speakers 34b may be one or multiple.

[0045] Figure 5 is a flowchart illustrating the flow of sound generation processing in Embodiment 2. In Figure 5, the case where the sensory parameter X is vehicle speed is used as an example. As shown in Figure 5, first in step S11, the vehicle sound detection unit 311 detects the vehicle sound. The vehicle sound detection unit 311 generates first data related to the vehicle sound based on the rotational speed of the engine 11 and the signal from the microphone 33, and transmits it to the comparison unit 312. Also, in step S12, the vehicle speed of the vehicle 100 is detected by the vehicle speed detection device 2. The vehicle speed detected by the vehicle speed detection device 2 is transmitted to the comparison unit 312.

[0046] Then, in step S13, the comparison unit 312 compares the first data relating to the detected vehicle sound with the second data relating to the reference sound stored in the memory unit 32 at the detected vehicle speed, and determines whether the vehicle sound and the reference sound are the same. If the comparison results in the vehicle sound and the reference sound being the same (S13: YES), the process returns to step S11. In other words, if the vehicle sound and the reference sound are the same, there is no need to cancel or supplement the vehicle sound, and therefore no adjustment sound is generated from the vehicle sound generator 3A.

[0047] If the vehicle sound and the reference sound are not the same (S13: NO), in step S14, the data generation unit 313 generates cancellation data to cancel the vehicle sound Dv. Here, the data generation unit 313 generates cancellation data with the opposite phase to the vehicle sound Dv using a known method as active noise cancellation. Then, in step S15, the cancellation data generated by the data generation unit 313 is output to the first speaker 34a, and the first speaker 34a outputs a sound corresponding to the cancellation data. As a result, the vehicle sound (such as the booming sound of the engine 11) occurring inside the vehicle cabin is canceled.

[0048] Furthermore, in step S16, the data generation unit 313 generates pseudo-data corresponding to the reference tone Ds. Here, the data generation unit 313 generates pseudo-data that includes the same elements as the second data of the reference tone Ds using a known method as active sound control. More specifically, the data generation unit 313 refers to the second data of the reference tone Ds stored in the storage unit 32 and generates pseudo-data that includes elements of the reference tone Ds corresponding to the current vehicle speed detected by the vehicle speed detection device 2. Then, in step S17, the pseudo-data generated by the data generation unit 313 is output to the second speaker 34b, and a sound corresponding to the pseudo-data is output from the second speaker 34b. As a result, a sound corresponding to the reference tone Ds is generated inside the vehicle and perceived by the driver as a sound according to their senses. Note that the order of the processes in steps S14-S15 and steps S16-S17 may be reversed, or the processes in steps S14-S15 and steps S16-S17 may be performed in parallel.

[0049] As described above, the vehicle sound generator 3A of this embodiment also stores a reference sound corresponding to the driver's perception in advance and generates an adjustment sound to adjust the vehicle sound to become the reference sound. As a result, the driver can perceive sounds that are in line with their own perception while the vehicle 100 is in motion, improving comfort.

[0050] Embodiment 3. Embodiment 3 will now be described. Embodiment 3 differs from Embodiment 1 in that it includes second data of multiple types of reference sounds. The configuration of the vehicle sound generator 3 in this embodiment is the same as in Embodiment 1.

[0051] The memory unit 32 of this embodiment stores multiple second data sets relating to multiple types of reference tones. Here, taking Figure 2 as an example, the second data relating to reference tones is a linear graph shown in Figure 2, and the reference tones are the sound elements at each point on the linear graph. In other words, the second data is data of a set of multiple reference tones. Each of the multiple reference tones included in the second data is determined according to at least one of one or more sensory parameters X that reflect the driver's senses. For example, each of the multiple reference tones included in the second data is determined according to at least one of the following: vehicle speed, accelerator pedal depression amount, brake pedal depression amount, vibration of the vehicle 100, and image from a camera mounted on the vehicle 100, steering angle information (steering wheel angle), outside temperature of the vehicle 100 (outside air temperature), inside temperature of the vehicle 100 (cabin temperature), time of day, and weather.

[0052] On the other hand, the multiple types of secondary data are determined from indicators different from the sensory parameter X. For example, each of the multiple types of secondary data is set according to the driver's attributes (gender, age, driving history, etc.) or the driver's personality. Alternatively, each of the multiple types of secondary data is set according to the driver's mood (e.g., happy, sad, angry, or calm) or the driver's preference (e.g., want to feel speed, or want to feel safe). In these cases, experiments are conducted according to the driver's attributes, personality, mood, or preference to acquire the multiple types of secondary data, which are then stored in the memory unit 32.

[0053] Furthermore, each of the multiple types of second data may be set for each time period. In this case, the sensory parameter X that defines each of the multiple reference sounds included in the second data does not necessarily have to include the time period. When each of the multiple types of second data is set for each time period, as an example, the sound pressure of the reference sound during the nighttime period is set lower than the sound pressure during the daytime period. This allows for quieter driving during the nighttime period. Also, each of the multiple types of second data may be set for each location where the vehicle 100 is driving. Since the driver's mood differs depending on whether the vehicle 100 is driving in a rural area, along the coast, or in an urban area, it is preferable to select according to the driver's mood. In this case, information about the location (scenery) where the vehicle 100 is driving, obtained from external video or GPS, does not necessarily have to be included in the sensory parameter X.

[0054] The driver selects one of several types of secondary data and inputs information indicating the selected secondary data via an interface such as an operation panel provided in the vehicle 100. Alternatively, the driver inputs information such as the driver's attributes, personality, mood, or preferences, time of day, or location where the vehicle 100 is traveling. If each of the several types of secondary data is set for each time of day, the driver may be able to input an instruction to automatically switch the secondary data for each time of day. Alternatively, if each of the several types of secondary data is set for each time of day, and the sensory parameter X includes the time of day, the time of day input by the driver, or the secondary data selected by the driver, may take precedence. In detail, if the sensory parameter X includes the time of day, the reference tone will automatically change each time the time of day changes, but the driver may be able to select the reference tone for their preferred time of day regardless of the actual time of day. Alternatively, for reasons such as driver safety or environmental considerations, processing based on the sensory parameter X including the time of day may be performed to conform to the actual time of day rather than the content input by the driver. Furthermore, if multiple types of second data are set for each location, and the sensory parameter X includes location information, the second data corresponding to the location information entered by the driver may be prioritized. This allows, for example, a driver to feel a sense of security as if they were in a rural landscape when driving in an urban area and wanting to relax. Alternatively, for reasons such as driver safety or environmental considerations, processing based on the sensory parameter X including location may be performed to better match the actual location than the content entered by the driver.

[0055] The comparison unit 312 selects one of several types of second data in response to input from the driver, etc., and compares the selected second data with the first data of the vehicle sound.

[0056] Figure 6 is a flowchart illustrating the flow of sound generation processing in Embodiment 3. As shown in Figure 6, first, in step S21, information is input for the driver to select one of several types of second data. As described above, here, the driver inputs information such as the driver's attributes, personality, mood or preference, time of day, or the location where the vehicle 100 is traveling. Alternatively, information indicating one of the several types of second data selected by the driver is input.

[0057] In the subsequent step S22, the comparison unit 312 extracts one of several types of second data stored in the storage unit 32 according to the input content. For example, if driver attributes are input, the comparison unit 312 selects and extracts the second data corresponding to the input attribute from among the several types of second data stored in the storage unit 32. Alternatively, if nighttime is input as the time of day, the comparison unit 312 selects and extracts the second data corresponding to nighttime from among the several types of second data stored in the storage unit 32. After that, the same steps S1 to S7 as in Embodiment 1 are performed using the selected reference tone second data.

[0058] As described above, the vehicle sound generator 3 of this embodiment can further improve driver comfort by selecting one of several types of second data set according to the driver's input, etc., from among the driver's attributes, personality, mood, or preferences, time of day, or location where the vehicle 100 is traveling, and generating an adjusted sound.

[0059] The above describes the embodiments, but the present invention is not limited to the above embodiments, and can be modified and combined in various ways without departing from the spirit of the present invention. For example, each functional unit of the control unit 31 of the vehicle sound generating device 3 may be provided in an ECU (Electronic Control Unit), which is a processor that comprehensively controls the operation of various devices provided in the vehicle 100.

[0060] Furthermore, the second data of the reference tone stored in the memory unit 32 may be updated, added to, or adjusted (for example, by fine-tuning the graph of the second data in Figure 2) by the driver or the like. In this case, the second data is updated via an interface such as an operation panel provided in the vehicle 100. This allows the driver to arbitrarily adjust the reference tone according to their preference.

[0061] Furthermore, in the above embodiment, if the vehicle sound and the reference sound are different, the vehicle sound is canceled and a simulated sound corresponding to the reference sound is generated. However, the method of adjusting the vehicle sound in the vehicle sound generator 3 is not limited to this. For example, the vehicle sound generator 3 may generate an adjusted sound based on the comparison results of the sound pressure, pitch, and timbre of the vehicle sound and the reference sound. Specifically, the comparison unit 312 compares the sound pressure, pitch, and timbre of the vehicle sound at the current vehicle speed with the sound pressure, pitch, and timbre of the reference sound at that vehicle speed, and outputs the comparison results to the data generation unit 313. In this case, the comparison results include the magnitude relationship between the sound pressure of the vehicle sound and the sound pressure of the reference sound, the pitch relationship between the pitch of the vehicle sound and the pitch of the reference sound, and the analogous relationship between the timbre of the vehicle sound and the timbre of the reference sound.

[0062] The data generation unit 313 then generates cancellation data and / or pseudo-data based on the comparison results of the comparison unit 312. For example, if the sound pressure of the vehicle sound is greater than the sound pressure of the reference sound, and the pitch and timbre are the same for both the vehicle sound and the reference sound, the data generation unit 313 generates cancellation data to suppress the vehicle sound so that its sound pressure becomes equal to the sound pressure of the reference sound, and does not generate pseudo-data. In this case, a sound corresponding to the cancellation data is output from the speaker 34 as an adjustment sound. Alternatively, if the sound pressure of the vehicle sound is less than the sound pressure of the reference sound, and the pitch and timbre are the same for both the vehicle sound and the reference sound, the data generation unit 313 generates pseudo-data to supplement the vehicle sound so that its sound pressure becomes equal to the sound pressure of the reference sound, and does not generate cancellation data. In this case, a sound corresponding to the pseudo-data is output from the speaker 34 as an adjustment sound. In this modified example as well, the driver can perceive sounds that are in line with their own senses while the vehicle 100 is in motion, improving driver comfort. [Explanation of Symbols]

[0063] 1 Drive unit, 2 Vehicle speed detection unit, 3, 3A Vehicle sound generator, 11 Engine, 31 Control unit, 32 Memory unit, 33 Microphone, 34 Speaker, 34a First speaker, 34b Second speaker, 100, 100A Vehicle, 311 Vehicle sound detection unit, 312 Comparison unit, 313 Data generation unit.

Claims

1. A sound detection unit (33) that detects vehicle noise generated by the movement of the vehicles (100, 100A), Output units (34, 34a, 34b) output an adjusted sound based on first data relating to the vehicle sound and second data relating to a reference sound corresponding to the driver's perception, A vehicle sound generator (3, 3A) equipped with the above.

2. The adjustment sound is generated based on the comparison result between the elements of the vehicle sound and the elements of the reference sound. The vehicle sound generating device (3, 3A) according to claim 1, wherein the element is at least one of sound pressure, pitch, and timbre.

3. The vehicle sound generating device (3, 3A) according to claim 1 or 2, wherein the reference sound is determined according to at least one of the following: the speed of the vehicle (100, 100A), the amount the accelerator is pressed, the amount the brake is pressed, the vibration of the vehicle (100, 100A), the image from a camera mounted on the vehicle (100, 100A), steering angle information, the external temperature of the vehicle (100, 100A), the internal temperature of the vehicle (100, 100A), the time of day, and the weather.

4. The vehicle sound generating device (3, 3A) according to claim 1 or 2, wherein the adjustment sound is a sound that causes the driver to perceive the reference sound.

5. A storage unit (32) that stores multiple types of the aforementioned second data, The vehicle sound generating device (3, 3A) according to claim 1 or 2, further comprising: a control unit (31) that extracts any of the above-mentioned second data from among the plurality of types of the above-mentioned second data in accordance with the input of the driver, and controls the output unit (34, 34a, 34b) to output the adjustment sound based on the extracted second data.

6. The vehicle sound generating device (3, 3A) according to claim 1 or 2, wherein the second data is updatable.

7. The vehicle sound generating device (3, 3A) according to claim 1 or 2, wherein the vehicle (100, 100A) is equipped with a continuously variable transmission.

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