Noise control method for a hybrid vehicle

Abstract

A noise control method for a hybrid vehicle having both an internal combustion engine (20) and a motor (30) as drive sources, the method comprising: Checking a driving state of the hybrid vehicle by a controller (10); when the driving state of the hybrid vehicle is an internal combustion engine driving state, calculating a first virtual noise for optimizing an internal combustion engine noise with the controller (10) by extracting main order components of the internal combustion engine (20) based on an engine speed and engine load data and by optimizing an arrangement of the extracted main order components of the internal combustion engine (20) or by adjusting their output levels; when the driving state of the hybrid vehicle is a motor driving state, calculating a second virtual noise for generating an optimized internal combustion engine noise with the controller (10) by extracting order components of the engine (30) based on an engine speed and engine load data, converting the extracted order components of the engine (30) into corresponding main order components of the internal combustion engine (20), and by optimizing an arrangement of the converted main order components of the internal combustion engine (20) or by adjusting their output levels; and after calculating the first virtual sound or the second virtual sound, outputting the calculated first virtual sound or the calculated second virtual sound by the controller (10) to a sound device of the hybrid vehicle; wherein, when the driving state is switched between an internal combustion engine driving state and a motor driving state, the method further includes: Calculating a third virtual sound by the controller (10) that represents a target driving state; Causing the controller (10) to gradually change the virtual sound from the virtual sound of a previous driving state to the third virtual sound over a predetermined period of time; and Outputting the calculated third virtual noise and the gradual transition by the controller (10) to the noise device.

Description

BACKGROUND TECHNICAL AREA

[0001] The present invention generally relates to a noise control method for a hybrid vehicle having both an internal combustion engine and a motor as drive sources, wherein an optimized vehicle noise is provided to a driver according to a driving state of the hybrid vehicle. DESCRIPTION OF THE RELATED PRIOR ART

[0002] Recently, due to the introduction of vehicles such as hybrid vehicles that use both fossil fuel and a battery as a power source, and electric vehicles that use a battery as a power source, installation of a noise generating device in an environmentally friendly vehicle has become mandatory since these types of vehicles generate little noise.

[0003] In the United States, laws are being considered that would require an environmentally friendly vehicle to produce noise above a certain level.

[0004] In general, vehicle noise, the lack of vehicle noise, or monotonous vehicle noise can be unpleasant for drivers. Pedestrians may also find vehicle noise unpleasant. However, vehicle noise can prevent accidents because such noise alerts pedestrians to the proximity of an approaching vehicle.

[0005] Furthermore, silence or a monotonous noise in a hybrid vehicle can have a negative impact on a driver. For example, it can degrade the driving experience, or there is a risk of the driver falling asleep during motor driving mode, as there is no unique sound from an internal combustion engine. Furthermore, regenerative braking can cause discomfort while driving.

[0006] US 2017 / 0 123 754 A1 discloses a vehicle sound generation device comprising a vehicle state detection unit, a storage unit, a sound source reproduction unit, a sound source amplification unit, a sound output unit, and a control unit. The vehicle state detection unit detects a vehicle speed, and the control unit calculates a corresponding shift factor corresponding to the vehicle speed from the speed shift profile and controls and outputs the sound pressure or pitch of the operating sound. The present invention generates and controls a virtual operating sound to generate a virtual sound that imitates a real sound of an internal combustion engine. Techniques related to a sound control mode in an internal combustion engine driving state or an electric motor driving state are essentially presented.

[0007] WO 2011 / 092 282 A1 relates to a method for operating a hybrid vehicle with at least one electric motor and at least one internal combustion engine, wherein the internal combustion engine is operated in a stationary manner in a first operating range of the vehicle and deactivated in at least a second operating range of the vehicle. To enable a constant background noise without sudden changes, a background noise corresponding to the operating noise of the internal combustion engine is generated during the second operating range.

[0008] The published patent applications US 2017 / 0 330 550 A1, US 2013 / 0 343 570 A1 and US 2015 / 0 002 287 A1 concern further noise control methods for motor vehicles.

[0009] The foregoing is merely intended to assist in understanding the background of the present invention and is not intended to imply that the present invention falls within the scope of related art already known to those skilled in the art. SUMMARY OF REVELATION

[0010] The present disclosure addresses the above problems by providing a noise control method for a hybrid vehicle in which an interior noise of the hybrid vehicle is maintained constant and a driver is provided with an appropriate virtual noise according to a driving condition, regardless of whether the driver is traveling at a constant speed or not. Consequently, the driver does not have to feel discomfort during driving due to noise changes, thus improving the driving experience.

[0011] To achieve the above object, according to an exemplary embodiment, there is provided a noise control method for a hybrid vehicle having both an engine and a motor as drive sources, the method comprising the steps of: checking a running state of the hybrid vehicle by a controller; when the running state of the hybrid vehicle is an engine running state, calculating a first virtual noise for optimizing an engine noise with the controller by extracting main order components of the engine based on an engine speed (RPM) and engine load data and by optimizing an arrangement of the extracted main order components of the engine or by adjusting their output levels;when the driving state of the hybrid vehicle is an engine driving state (EV mode), calculating a second virtual sound to generate an optimized engine sound with the controller by extracting order components of the engine based on an engine speed and engine load data, converting the extracted order components of the engine into corresponding main order components of the engine, and optimizing an arrangement of the converted main order components of the engine or adjusting their output levels; and after calculating the first virtual sound or the second virtual sound, outputting the calculated first virtual sound or the second virtual sound to a sound device of the hybrid vehicle by the controller;

[0012] In addition, the noise control method, when the driving state is switched from the engine driving state to the motor driving state or vice versa, further comprises: calculating, by the controller, a third virtual noise representing a target driving state, and causing the controller to gradually change the virtual noise from the virtual noise of a previous driving state to the third virtual noise over a predetermined period of time; and outputting, by the controller, the calculated third virtual noise and gradual transition to the noise device.

[0013] In another embodiment, the sound control method further includes: after calculating the first virtual sound or the second virtual sound, checking by the controller whether or not a difference value of the traveling speed of the vehicle is 0, that is, whether the vehicle speed is constant, wherein, when the difference value of the traveling speed is 0, the controller stops outputting the first virtual sound or the second virtual sound.

[0014] In another embodiment, the noise control method may further comprise, when the difference value of the vehicle speed is not 0: adding an acceleration characteristic to the first virtual noise or the second virtual noise by the controller and outputting the added virtual noise to the noise device, wherein the acceleration characteristic is calculated based on a speed increase of the engine or the motor, a change rate of the vehicle speed and / or a pedal opening rate.

[0015] In another embodiment, the noise control method may further include: after calculating the first virtual noise or the second virtual noise, checking, by the controller, whether or not a driving mode of the hybrid vehicle is an ECO mode, a COMFORT mode, or a SPORT mode; and after checking the driving mode, adding, by the controller, a driving mode characteristic to the first virtual noise or the second virtual noise corresponding to the checked driving mode and outputting the added virtual noise to the noise device. The driving mode characteristic may be preset to amplify output levels of the main order components of the internal combustion engine. Specifically, the driving mode characteristic may be set such that the amplification level gradually increases between the ECO mode, the COMFORT mode, and the SPORT mode.

[0016] In a preferred embodiment, the controller may collect engine load data based on an engine vibration sensor, an engine sensor, a boost pressure sensor, and / or an exhaust pressure sensor to calculate the first virtual noise.

[0017] In a preferred embodiment, the controller may collect engine load data based on an engine vibration sensor, a voltage sensor, and / or a current sensor to calculate the second virtual noise.

[0018] According to various embodiments of the noise control method for the hybrid vehicle configured as described above, a vehicle noise corresponding to an engine driving state can be provided that matches the vehicle acceleration experience. Therefore, the driver can enjoy an enhanced acceleration experience.

[0019] In addition, in an engine driving condition, the acceleration experience can be improved by generating a virtual combustion engine sound corresponding to a driving situation.

[0020] In addition, the driving experience can be improved by gradually changing the sound pressure level during a change in the driving state of the hybrid vehicle.

[0021] In addition, the driving experience is enhanced by providing an appropriate output level of the virtual sound according to a speed, acceleration, deceleration and / or driving mode of the hybrid vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and other advantages of the present disclosure will become more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a flowchart illustrating a noise control method for a hybrid vehicle in accordance with an exemplary embodiment; Fig. 2 is a view showing a noise control system for a hybrid vehicle in accordance with an exemplary embodiment; Fig. 3 is a view showing a noise control flow when the hybrid vehicle is in an engine running state according to an exemplary embodiment; Fig. 4 is a view showing a noise control flow in accordance with an exemplary embodiment when the hybrid vehicle is in a motor running state; and Fig. 5 is a graph of a change in the sound pressure level of the hybrid when a virtual sound is output to a sound device in accordance with an exemplary embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, exemplary embodiments of a noise control method for a hybrid vehicle will be described in detail with reference to the accompanying drawings.

[0024] Fig. 1 is a flowchart showing a noise control method for a hybrid vehicle in accordance with an exemplary embodiment, and Fig. 2 is a view showing a noise control system for a hybrid vehicle in accordance with an exemplary embodiment.

[0025] Referring to Fig. 1 and Fig. 2, the noise control method for the hybrid vehicle having an engine 20 and a motor 30 as drive sources may include: checking a driving state of the hybrid vehicle by a controller 10 (step S100); when the driving state determined in step (S100) is an engine driving state (HEV mode), calculating, by the controller 10, a first virtual noise that optimizes an engine noise by extracting main order components of the engine 20 based on an engine speed and engine load data, and optimizing an arrangement of the main order components or adjusting their output levels (step S110);When the driving state determined in step (S110) is an engine driving state (EV mode), the controller 10 calculates a second virtual sound that generates an optimized engine sound by extracting main order components of the engine 30 based on an engine speed and engine load data, converts the extracted order components of the engine 30 into corresponding main order components of the engine 20, and optimizes an arrangement of the converted main order components of the engine 20 or adjusts their output levels (step S120); and after calculating the first virtual sound or the second virtual sound, the controller 10 outputs the calculated first virtual sound or the second virtual sound to a sound device 40 of the hybrid vehicle (step S160).

[0026] Generally speaking, in the hybrid vehicle noise control method according to this exemplary embodiment, when the driving state of the hybrid vehicle is set to an HEV mode that uses the engine 20 as the main power source, a first virtual noise calculated consistent with the characteristics of the engine 20 is output to the hybrid vehicle noise device 40. When the driving state of the hybrid vehicle is set to an EV mode that uses the motor 30 as the main power source, a second virtual noise calculated consistent with the characteristics of the motor 30 is output to the hybrid vehicle noise device 40. Thus, a vehicle noise matching a vehicle state is provided.

[0027] In detail, the controller 10 first checks the driving state of the hybrid vehicle in step (S100). In another exemplary embodiment, the controller 10 may check a driving state of a current vehicle by communicating with a hybrid control unit (HCU).

[0028] When the driving state is determined to be an internal combustion engine driving state (hybrid electric vehicle mode: HEV mode), noise is generated during the combustion process of the internal combustion engine. Therefore, in step (S120), the controller 10 calculates a first virtual noise to minimize the combustion noise and provide a dynamic driving experience to a driver, and outputs the calculated first virtual noise to the noise device 40 in step (S160).

[0029] Fig. 3 is a view showing a noise control flow when the hybrid vehicle is in an engine running state according to an exemplary embodiment. When the running state of the hybrid vehicle is an engine running state, the controller 10 extracts the noise with reference to FIG. Fig. 1 to 3, a main order frequency of the internal combustion engine 20 is determined from an engine speed, and extracts main order components among order components of the internal combustion engine 20 necessary for controlling a vehicle noise by performing a Fast Fourier Transform (FFT) analysis based on the extracted main order frequency and engine load data. The controller 10 adjusts an arrangement of the extracted main order components according to an engine characteristic, adjusts a level difference between respective order components, and outputs the adjusted arrangement and the adjusted level difference to the noise device 40. Consequently, a vehicle noise optimized for the driving condition can be provided.The main order component of the internal combustion engine means a specific order component that is required to control a vehicle among all measured internal combustion engine order components, such as internal combustion engine noise, internal combustion engine vibrations, etc.

[0030] Additionally, when the driving state of the hybrid vehicle is a motor driving state (electric vehicle mode: EV mode), white noise is generated while the engine is rotating. The controller 10 outputs a virtual engine sound related to a driving speed of the hybrid vehicle by using the sound device 40, allowing the driver to hear a natural engine sound during the motor driving state, thereby enhancing the driving experience.

[0031] Fig. 4 is a view showing a noise control flow according to an exemplary embodiment when the hybrid vehicle is in a motor running state. When the running state of the hybrid vehicle is a motor running state, the controller 10 extracts the noise control flow with reference to FIG. Fig. 1, Fig. 2 and Fig. 4 order components of the engine 30 from an engine speed and calculates order components of the internal combustion engine 20 corresponding to the extracted order components of the engine 30. In a preferred embodiment, the order components of the engine 30 are converted into the main order components of the internal combustion engine 20 by performing an FFT analysis based on the calculated order components of the internal combustion engine 20 and the engine load data. Then, the controller 10 adjusts an arrangement of the converted main order components of the internal combustion engine 20 and a level difference between respective order components, and outputs the adjusted arrangement and the level difference to the sound device 40, so that an optimized vehicle sound can be provided to the driver during an engine driving condition.

[0032] In particular, in an engine driving state, the controller 10 may calculate a second virtual sound corresponding to the main order component of the internal combustion engine 20 in real time and output the calculated second virtual sound to the sound device 40. Alternatively, the controller 10 may be configured to store a second virtual sound calculated according to an engine characteristic and output the previously stored second virtual sound to the sound device 40 when a driving situation corresponding to the stored virtual sound occurs in an engine driving state.

[0033] Generally, primary order components of a four-cylinder internal combustion engine are extracted as secondary order components, and primary order components of a six-cylinder internal combustion engine are extracted as tertiary order components. Furthermore, in the exemplary embodiments, primary order components of the engine 30 are generated each time the engine 30 rotates, and the generated primary order components are converted into tertiary order components when the internal combustion engine 20 is a six-cylinder internal combustion engine. Consequently, a virtual engine sound matching the engine characteristic can be output.

[0034] In a preferred embodiment, the sound device 40 may be an engine compartment speaker that outputs sound to the vehicle compartment, a vehicle compartment speaker, a frequency-specific filter speaker, and / or a pedestrian warning speaker that outputs sound to the exterior of the vehicle.

[0035] In a further exemplary embodiment of the invention, the controller 10 may, however, in step (S140), with reference to the Fig. 1 to 4, after calculating the first virtual sound or the second virtual sound in steps (S110) or (S120), check whether a difference value of the vehicle speed is 0 or not. If the difference value of the vehicle speed is determined to be 0 in step (S140), the controller 10 may stop outputting the first virtual sound or the second virtual sound of step (S160).

[0036] In other words, the driving speed difference value is an index that reflects the instantaneous flow of driving speed. When the driving speed difference value is determined to be 0, it can be determined that the driver is driving the hybrid vehicle at a constant speed.

[0037] If a virtual engine sound is output by the sound device 40 while the driver drives the hybrid vehicle at a constant speed as above, the NVH (Noise, Vibration, and Harshness) performance of the hybrid vehicle deteriorates. To maintain silence for improving the NVH performance of the hybrid vehicle, the output of the first virtual sound or the second virtual sound of step (S160) may be stopped. Alternatively, the silence of the hybrid vehicle may be improved by converting and outputting the first virtual sound or the second virtual sound to a sound source having a phase opposite to the noise measured inside the vehicle.

[0038] If the vehicle speed difference value is not determined to be 0 in step (S140), the controller 10 adds an acceleration characteristic to the first virtual sound or the second virtual sound in step (S160) and outputs the added virtual sound. The acceleration characteristic is calculated based on a speed increase of the engine or the motor, a vehicle speed change rate, and / or a pedal opening rate.

[0039] In other words, if the vehicle speed difference value is not 0, it is determined that the driver is not traveling at a steady speed. The controller 10 determines whether the hybrid vehicle is in an acceleration state or a deceleration state by using an engine speed increase or a motor speed increase received from an engine control unit (ECU) and a motor control unit (MCU), a vehicle speed change rate received from a vehicle speed sensor, and / or a pedal opening rate received from an accelerator pedal sensor (APS), and outputs an appropriate corresponding virtual sound.

[0040] It is preferable to adjust the acceleration characteristic such that gain amounts of the output levels from the main order components of the internal combustion engine are increased as the acceleration of the hybrid vehicle increases.

[0041] When the controller 10 detects that the hybrid vehicle is in an acceleration state by using the speed increase of the engine or motor, the rate of change of the vehicle speed, and the accelerator opening rate data, the controller 10 amplifies the output levels of the main order components of the engine 20 to provide an engine sound that matches the corresponding acceleration characteristic, and outputs the amplified output levels to the sound device 40 to provide the driver with an improved driving experience.

[0042] The noise control method for the hybrid vehicle according to another embodiment further includes, after calculating the first virtual noise or the second virtual noise of step (S110) or step (S120), the step (S150) of checking by the controller 10 whether a driving mode of the hybrid vehicle is an ECO mode, a COMFORT mode, or a SPORT mode.

[0043] After checking the driving mode in step (S150), the controller 10 executes step (S160) by adding a driving mode characteristic to the first virtual sound or the second virtual sound and outputting the modified virtual sound. In a preferred embodiment, the driving mode characteristic is preset so that the output levels of the main order components of the internal combustion engine are amplified according to the driving mode. The driving mode characteristic is set so that the gain of the output levels gradually increases from ECO mode to COMFORT mode to SPORT mode.

[0044] In other words, the controller 10 provides a vehicle sound that matches the driving mode of the hybrid vehicle. A soft sound is provided in ECO mode, a crisp sound is provided in COMFORT mode, and a dynamic sound is provided in SPORT mode, allowing the driver to experience different driving experiences according to the driving mode.

[0045] In a preferred embodiment, when calculating the first virtual noise in step (S110), the controller 10 may collect the engine load data based on an engine vibration sensor, a combustion pressure sensor, a boost pressure sensor, and / or an exhaust pressure sensor.

[0046] Generally, during operation of the internal combustion engine 20, noise and vibration are generated due to the power stroke of the internal combustion engine 20, and the main order components of the internal combustion engine can be extracted using the information about the above internal combustion engine noise and vibration. Therefore, to detect a motion characteristic of the internal combustion engine 20, vibrations of the internal combustion engine 20 can be directly measured by an internal combustion engine sensor or can be indirectly measured using information about combustion pressure, boost pressure, and exhaust pressure. So that the controller 10 can generate a vehicle noise matching the motion characteristic of the internal combustion engine 20 based on the directly or indirectly measured vibration data.

[0047] Similarly, when calculating the second virtual noise in step (S120), the controller 10 may collect the engine load data based on an engine vibration sensor, a voltage sensor, and / or a current sensor.

[0048] In other words, to measure a vibration characteristic generated by the operating motor 30, a vibration sensor can be used directly. Alternatively, the vibration characteristic of the motor 30 can be measured indirectly by using a voltage sensor or a current sensor in which a vibration characteristic is predetermined according to a voltage or current of the motor 30.

[0049] Consequently, the controller 10 sets a target arrangement of the main order components of the internal combustion engine and its target output level according to the vibration characteristic of the internal combustion engine 20 or motor 30, and provides the driver with a vehicle sound that matches the driving performance of the hybrid vehicle. Consequently, the driver's driving experience is improved.

[0050] When the driving state is switched from the engine driving state to the motor driving state or vice versa in step (S100), the noise control method of the hybrid vehicle may further include the step (S130) of calculating, by the controller 10, a third virtual noise representing a target driving state and causing the controller to gradually change the virtual noise from the virtual noise of a previous driving state to the third virtual noise over a predetermined period of time; and outputting the third virtual noise calculated by the controller and gradually transmitting it to the noise device.

[0051] In other words, since there is a perceptible difference in vehicle noise when the hybrid vehicle is in an internal combustion engine driving state or in an engine driving state, the driver may experience discomfort because he or she perceives a perceptible difference in vehicle noise when the driving state switches.

[0052] Using the exemplary embodiment described above, the driver's driving experience can be enhanced because they perceive no difference in the vehicle noise when the driving state switches. By outputting the third virtual noise through the noise device 40 and gradually changing the sound pressure during the transition over a predetermined period of time, the disturbing noise for the driver is minimized.

[0053] Fig. 5 is a graph illustrating the change in sound pressure level of the hybrid vehicle when a virtual sound is output to a sound device in accordance with an exemplary embodiment.

[0054] As in Fig. As shown in Figure 5, when switching the driving mode from an EV mode to an HEV mode using an internal combustion engine, a noticeable difference in sound pressure is normally generated due to airborne noise transmitted from the internal combustion engine. However, by adopting the exemplary embodiments described above, the driver does not have to perceive a difference caused by a noise change because the sound pressure is gradually increased during a transition from the EV mode to the HEV mode.

[0055] According to the sound control method for the hybrid vehicle established as described above, a vehicle sound suitable for vehicle acceleration can be provided in accordance with an internal combustion engine driving state. Therefore, the driver can experience an enhanced acceleration experience.

[0056] In addition, in an engine driving condition, the acceleration experience can be improved by generating a virtual combustion engine sound corresponding to a driving situation.

[0057] In addition, the driver does not have to experience any discomfort caused by a noise change because a sound pressure level can be gradually adjusted when the driving state of the hybrid vehicle is switched.

[0058] In addition, the driver can perceive an improved driving experience because an appropriate output level of the virtual sound is provided in accordance with a speed, acceleration, deceleration and / or driving mode of the hybrid vehicle.

[0059] Although exemplary embodiments have been described for the purpose of illustration, it will be apparent to those skilled in the art that various modifications, additions and substitutions are possible without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A noise control method for a hybrid vehicle having both an internal combustion engine (20) and a motor (30) as drive sources, the method comprising: Checking a driving state of the hybrid vehicle by a controller (10); when the driving state of the hybrid vehicle is an internal combustion engine driving state, calculating a first virtual noise for optimizing an internal combustion engine noise with the controller (10) by extracting main order components of the internal combustion engine (20) based on an internal combustion engine speed and engine load data and by optimizing an arrangement of the extracted main order components of the internal combustion engine (20) or by adjusting their output levels; when the driving state of the hybrid vehicle is a motor driving state, calculating a second virtual noise for generating an optimized internal combustion engine noise with the controller (10) by extracting order components of the engine (30) based on an engine speed and engine load data, converting the extracted order components of the engine (30) into corresponding main order components of the internal combustion engine (20), and by optimizing an arrangement of the converted main order components of the internal combustion engine (20) or by adjusting their output levels; and after calculating the first virtual sound or the second virtual sound, outputting the calculated first virtual sound or the calculated second virtual sound by the controller (10) to a sound device of the hybrid vehicle; wherein, when the driving state is switched between an internal combustion engine driving state and a motor driving state, the method further includes: Calculating a third virtual sound by the controller (10) that represents a target driving state; Causing the controller (10) to gradually change the virtual sound from the virtual sound of a previous driving condition to the third virtual sound over a predetermined period of time; and Outputting the calculated third virtual noise and the gradual transition by the controller (10) to the noise device. [2] The method of claim 1, further comprising: after calculating the first virtual noise or the second virtual noise, checking a difference value of a driving speed by the controller (10). [3] The method according to claim 2, wherein when the calculated difference value of the vehicle speed is 0, the controller stops outputting the first virtual sound or the second virtual sound; and when the difference value of the vehicle speed is not 0, the method further includes: adding an acceleration characteristic to the first virtual sound or the second virtual sound by the controller and outputting the added virtual sound to the sound device. [4] A method according to claim 3, wherein the acceleration characteristic is calculated based on a speed increase of the internal combustion engine (20) or the motor (30), a rate of change of the driving speed and / or a pedal opening rate. [5] A method according to any one of the preceding claims, further comprising: after calculating the first virtual noise or the second virtual noise, checking by the controller (10) whether a driving mode of the hybrid vehicle is an ECO mode, a COMFORT mode or a SPORT mode; and Adding a driving mode property to the first virtual sound or the second virtual sound according to the determined driving mode by the controller (10), and Output the added virtual sound to the sound device. [6] The method of claim 5, wherein the driving mode characteristic is preset to amplify output levels of the main order components of the internal combustion engine (20), and wherein the driving mode characteristic is adjusted to gradually increase a gain of the output levels as the driving mode changes from an ECO mode to a COMFORT mode to a SPORT mode. [7] A method according to any one of the preceding claims, wherein, in calculating the first virtual noise, the controller (10) collects the engine load data based on an engine vibration sensor, an engine sensor, a boost pressure sensor and / or an exhaust pressure sensor. [8] A method according to any one of the preceding claims, wherein, in calculating the second virtual noise, the controller (10) collects the engine load data based on an engine vibration sensor, a voltage sensor and / or a current sensor.

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