Method and apparatus for controlling driving sound of electric vehicle

Abstract

The invention relates to a method and an apparatus for controlling driving sound of an electric vehicle. A method of controlling an electric vehicle driving sound using a motor vibration and a virtual transmission signal includes: extracting, by a signal processing controller, a vibration level of an Nth order component having a maximum linearity for a motor output torque among order components extracted from a vibration signal of a rotating electric vehicle (EV) motor and a virtual engine RPM; converting, by the signal processing controller, a revolution per minute (rpm) of the EV motor into a frequency to determine a frequency for each order component; the EV mode travel sound is set by the signal processor by applying a vibration level of the Nth order component to a frequency level of each order component to be output and rearranging the order components such that a number of revolutions per minute of the virtual engine reflects a travel mode changed according to the number of virtual gears.

Description

Technical Field

[0001] The present disclosure relates to a method for controlling a driving sound of an electric vehicle based on a motor vibration, the method controlling the driving sound of the electric vehicle based on the motor vibration and a virtual transmission signal of the electric vehicle using the motor as a power source. Background Art

[0002] Recently, with the emergence of vehicles that do not generate engine noise, such as electric vehicles (EVs) that can travel using an electric motor, eco-friendly vehicles have become required to be equipped with noise generating devices. Generally, the noise generated by a vehicle causes some discomfort not only to the driver but also to pedestrians around the vehicle, but the noise is used to increase the vehicle recognition ability of pedestrians to recognize surrounding vehicles through vision and hearing and prevent traffic accidents.

[0003] Therefore, a driving sound control for an EV has been developed to store and play a virtual sound because, unlike an internal combustion engine vehicle, an EV is very quiet during acceleration / deceleration and generates only high-frequency electromagnetic noise.

[0004] Recent driving sound control technologies are considered a salable aspect of a vehicle by improving a driver's driving pleasure through hearing and vision. Therefore, it is necessary to store and generate music or sounds suitable for an EV.

[0005] The information included in this background of the present disclosure is only for enhancing an understanding of the general background of the present disclosure and may not be regarded as an admission or any form of suggestion that this information forms the prior art known to those skilled in the art. Summary of the Invention

[0006] Aspects of the present disclosure aim to provide a technology for controlling a driving sound desired by a customer according to a performance of an electric vehicle (EV) based on characteristics of a motor that replaces a conventional internal combustion engine, and to provide a technology for controlling a driving sound of an EV that can extract, in real time, an order component of a motor vibration having a high correlation with a motor output characteristic of the EV corresponding to a power performance of an internal combustion engine through a virtual engine revolutions per minute (RPM) and a virtual number of gears, and then implement a driving sound according to a power performance characteristic of the vehicle.

[0007] A method for controlling the driving sound of an electric vehicle using motor vibration and virtual transmission signals according to an exemplary embodiment of the present disclosure includes: extracting, by a signal processing controller, a vibration level of an Nth-order component having the maximum linearity for motor output torque among the order components extracted from the vibration signal of a rotating electric vehicle (EV) motor and a virtual engine RPM; determining, by the signal processing controller, the frequency of each order component by converting the RPM of the EV motor into a frequency; and setting the driving sound in the EV mode by the signal processing controller applying the vibration level of the Nth-order component to the frequency level of each order component to be output and rearranging the order components such that the virtual engine RPM reflects the driving mode changed according to the virtual number of gear positions.

[0008] In addition, the Nth-order component may be the Nth-order component whose determination coefficient R 2 is 90% or more, and the order component may be determined by a vibration sensor configured to detect the vibration signal of the EV motor.

[0009] In addition, the virtual engine RPM may be determined by Equation 1, [Equation 1] Virtual engine RPM = Actual measured motor RPM × Transmission ratio of virtual target stage.

[0010] In addition, for the virtual number of gear positions, the difference between the virtual target gear and the virtual current gear may be caused by the transmission forward rate of Equation 2, [Equation 2] Transmission forward rate = (Virtual engine RPM - Current gear RPM) / (Target gear RPM - Current gear RPM) × 100%.

[0011] Another method for controlling the driving sound of an electric vehicle using motor vibration and virtual transmission signals according to an exemplary embodiment of the present disclosure includes: extracting, by a signal processing controller, the Nth-order component having the maximum linearity for motor output torque among the order components extracted from the vibration signal of a rotating electric vehicle (EV) motor and a virtual engine RPM; determining, by the signal processing controller, the frequency of each order component by converting the RPM of the EV motor into a frequency; and setting the driving sound in the EV mode by the signal processing controller applying the vibration level of the Nth-order component to the frequency level of each order component to be output and reconfiguring the order components, wherein the virtual engine RPM changes according to the virtual number of gear positions.

[0012] In addition, extracting the Nth-order component may include performing a fast Fourier transform (FFT) on the vibration signal and resampling by a non-uniform fast Fourier transform (NFFT).

[0013] In addition, extracting the Nth-order component may include: using order tracking analysis of the EV motor and an RPM-based band-pass filter to extract the Nth-order component.

[0014] The present disclosure provides a technique for controlling a motor vibration signal and a virtual drive signal based on an EV to match the performance of a vehicle and a driving sound desired by a user, and can extract an order component of motor vibration having a high correlation with the motor output characteristics of the EV, and then realize a driving sound available in an internal combustion engine through a virtual engine RPM and the number of gear positions to match the dynamic performance characteristics of the vehicle.

[0015] The methods and apparatuses of the present disclosure have other features and advantages that will be apparent from or more particularly set forth in the accompanying drawings and the following detailed description, which are incorporated herein and together serve to explain certain principles of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a diagram exemplarily showing an electric vehicle (EV) to which the present disclosure is applied.

[0017] Figure 2 is a diagram exemplarily showing signals and data flows from an input signal to an output of a driving sound according to an exemplary embodiment of the present disclosure.

[0018] Figure 3A 、 Figure 3B and Figure 3C are graphs showing changes in output torque of each load and changes in an order level according to the position of a vibration sensor.

[0019] Figure 4 is a block diagram of a control algorithm from an input signal to a sound output according to an exemplary embodiment of the present disclosure.

[0020] Figure 5A and Figure 5B are diagrams for describing a process and results of extracting an Nth order level using a fast Fourier transform (FFT) analysis algorithm applied to the present disclosure.

[0021] Figure 6A 、 Figure 6B and Figure 6C are diagrams for describing a process and results of extracting an Nth order level using an order tracking algorithm applied to the present disclosure.

[0022] Figure 7 is a diagram for describing a process of determining a virtual engine RPM and the number of virtual transmission gear stages.

[0023] Figure 8A and Figure 8BA diagram for comparing the motor vibration signals before and after applying the virtual drive signal of the present disclosure.

[0024] It can be understood that the accompanying drawings are not necessarily drawn to scale and present a slightly simplified representation of various features illustrating the basic principles of the present disclosure. Specific design features of the present disclosure included herein (including, for example, specific dimensions, orientations, positions, and shapes) will be determined in part by the specific intended application and use environment.

[0025] In the accompanying drawings, throughout several views of the drawings, reference numerals refer to the same or equivalent components of the present disclosure. Detailed Description

[0026] Reference will now be made in detail to various embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings and described below. Although the present disclosure will be described in conjunction with the exemplary embodiments of the present disclosure, it should be understood that this specification is not intended to limit the present disclosure to those exemplary embodiments. On the other hand, the present disclosure is intended to cover not only the exemplary embodiments of the present disclosure, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the present disclosure as defined by the appended claims.

[0027] Hereinafter, various exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and these embodiments are examples and can be implemented in various different forms by those skilled in the art to which the present disclosure pertains, and thus are not limited to the various exemplary embodiments included herein.

[0028] Figure 1 is a diagram exemplarily showing an electric vehicle (EV) to which the present disclosure is applied, and Figure 2 is a diagram exemplarily showing the signals and data streams from the input signal to the output of the driving sound according to an exemplary embodiment of the present disclosure.

[0029] Reference Figure 1 , installed in the EV to implement the present disclosure, includes a vibration sensor 10 for measuring the vibration signal generated when the motor rotates, a controller area network (CAN) signal 20 connected to the vehicle via CAN communication, a signal processing controller 30 for processing the vibration signal and the CAN signal, and a sound output device 40.

[0030] The vibration signal of the motor measured by the vibration sensor 10 is input to the signal processing controller 30, and the vibration characteristics according to the real-time motor rotation are measured. The vibration sensor 10 can be used by selecting from a vibration sensor for acquiring an analog signal and a micro-electromechanical system (MEMS) sensor including a knocking sensor method that can convert an analog signal into a digital signal through a digital signal conversion module and process the digital signal itself.

[0031] The CAN signal 20 can obtain the motor RPM, the opening of the accelerator pedal, and the vehicle speed in real time, and may include not only information related to the driving mode change, the motor torque, and the vehicle running characteristics, but also a signal for a virtual engine RPM and a virtual gear stage number in an exemplary embodiment of the present disclosure.

[0032] The signal processing controller 30 may be configured to determine the driving condition regarding the presence or absence of acceleration / deceleration / constant speed driving or the intention of the driver according to the vibration signal and the CAN signal as input signals, generate a target driving sound signal using the motor RPM and the vibration signal, and transmit the target driving sound signal as output data to the sound output device 40. As the signal processing controller, an on-board audio digital signal processor (DSP) may be applied. The DSP may be used for voice coding to digitize voice as an analog signal, and is an integrated circuit for allowing a mechanical device to quickly process digital signals.

[0033] The sound output device 40 can output the output data received from the signal processing controller through a speaker set in the engine compartment embedded with the motor to output a specific frequency band. In addition, the sound output device can be installed on the outside of the vehicle (which includes the front surface, rear surface and side surface of the vehicle) instead of the inside of the engine compartment, for protecting pedestrians and outputting through an audio speaker set in the interior of the vehicle for the driver or passengers, and the sound output device can be a thin speaker or a membrane playable device.

[0034] Figure 2 is a diagram exemplarily showing a process of obtaining real-time information related to motor vibration and motor RPM information from a vibration sensor and a vehicle CAN signal, performing calculations in a signal processing controller, and then outputting acceleration sensing sound to the interior of a vehicle through an external audio amplifier. As described above, the location of the sound output device may include not only the interior of the vehicle but also the exterior of the vehicle, the interior of an engine room, etc. In an exemplary embodiment of the present disclosure, a virtual engine RPM and a virtual number of gears are generated by a vehicle control unit (VCU) from real-time vibration signal information obtained from a vibration sensor and transmitted to a signal processing controller.

[0035] The vibration level caused by the rotation of the EV motor is a relatively low value compared to the level caused by the combustion of the internal combustion engine. Therefore, it is important to select the position of the sensor, which can accurately extract small changes in the vibration level. The method of selecting the position of the sensor is as follows.

[0036] First, a position with high amplitude when sweeping through the analysis of the structural analysis model of the EV motor is selected, and because the position should be a flat surface for mounting the vibration sensor, a position with high amplitude sensitivity relative to the flat surface should be selected. In addition, the vibration measurement direction of the vibration sensor is measured in a direction perpendicular to the mounting surface. In other words, the amplitude change in the direction perpendicular to the mounting surface can be predicted by analysis.

[0037] After the structural analysis, while changing the position of the sensor, the output torque change and the level change of each order of the motor vibration are measured for each load of the motor, and regression analysis is performed on the measured values ​​of the output torque change and the order level change. The position that produces the maximum amplitude and has a high sensitivity can be selected to extract the motor output characteristics and the determination coefficient R 2 The Nth order component is 0.9 or more, and the position where the linearity and level change characteristics best appear according to the characteristics of the amplitude caused by the motor vibration can be selected.

[0038] The power performance of the motor in the EV is expressed as the output torque of the motor. In an exemplary embodiment of the present disclosure, in order to control the driving sound based on the motor vibration, a component having a high correlation with the output torque trend of the motor in the order degree and order level characteristics of the motor based on the motor RPM among multiple pieces of information related to the vibration signal of the motor should be extracted and selected as the Nth order component. The order component is expressed differently according to the internal structure of the motor including the number of magnetic cores, etc.

[0039] Figure 3A is an embodiment for selecting an optimal position of a vibration sensor disposed on a motor, Figure 3B shows that the X-axis is the motor RPM, the Y-axis is the output torque and shows the change in output torque for each load, and Figure 3CIt shows that the X-axis is the motor RPM and the Y-axis is the change in level (dB) for each Nth load step. These are graphs for comparing the output torque, step degree, and step level change depending on the measured position. That is, by comparing the step components, the linearity of the output torque change of each load of the motor among the multiple step components of the vibration measured from the motor and the correlation with the linear factor according to the load change are determined.

[0040] As a result of the embodiment, a graph of motor RPM step degree (N th ) - step level (dB) is completed, and as a step component with high motor output torque and high correlation, the determination coefficient R 2 is determined to be 0.9 or greater for the 24th order as the reference Ref order.

[0041] Figure 4 is a block diagram of a control algorithm from various signal inputs (S10) to the output (S40) of the sound output device according to an exemplary embodiment of the present disclosure.

[0042] As input signals, the vibration signal of the EV motor is measured by using the vibration sensor 10, and the EV motor RPM, pedal opening, vehicle speed data, driving mode, virtual engine RPM, and virtual gear position are input from the CAN signal 20. The algorithm from signal input (S10) to output (S40) is determined by the signal processing controller 30, and the final output is executed by the sound output device 40 including the indoor / outdoor audio speakers.

[0043] The Nth order component is extracted from the motor vibration signal obtained by the vibration sensor 10, and it is determined as the reference Ref order with the determination coefficient R 2 being 0.9 or greater, and the level (S30) of the Nth order component (i.e., the reference Ref order component) is determined.

[0044] By first calculating the reference Ref order component once from the Nth order component and then inputting the reference Ref order component to the signal processing controller, it can always be used as the reference Ref order component. At the same time, by extracting the Nth order component from the motor vibration signal at a specific time, the reference Ref order component can be set to be automatically determined by the signal processing controller.

[0045] At the same time, in S31, step components (e.g., the second order / fourth order) generated for the motor RPM obtained in real time can be generated, and the motor RPM used instantaneously is the virtual motor RPM. The virtual motor RPM can be changed by virtual transmission gear shifting and is represented as the virtual engine RPM in the specification of this application.

[0046] When determining the Nth-order component that serves as a reference for the order level in S30, order rearrangement (S36) is performed by matching the order components generated in S31. Meanwhile, in S36, the amplification degree of the level of the arranged order components can be determined, and real-time amplification control can be executed.

[0047] The engine order component arrangement can be selected based on which one of the driving modes in the signal input (S10) information and the driving mode in S35 from the input information related to the virtual number of gears is in the energy-saving / normal / sports mode and the information related to the virtual number of gears, and this can be additionally reflected during order rearrangement in S36.

[0048] The virtual engine RPM and the virtual number of gears can be set to match the EV concept and be set to output virtual gear transmission information of a fast transmission pattern in the case of an EV that assigns performance, and output virtual gear transmission information of a soft transmission pattern in the case of a luxury-oriented EV. For the virtual engine RPM and the virtual number of gears, virtual engine RPM information, virtual shift time points, and information related to the virtual number of gears of a multi-gear (sixth gear, eighth gear, etc.) pattern suitable for the characteristics of the EV are provided through a virtual gearshift (VGS) algorithm as input values to the signal processing controller 30 from the signal input S10 through the VCU.

[0049] Meanwhile, the EV mode driving sound set in S36 can interact with the input signal or an external signal, and thus the calculated values (S38, S39, and S40) can be selectively changed. After passing through a variable frequency band filter based on the virtual engine RPM (S37), the result can be applied to S38.

[0050] The band filter is a band-pass filter and is a filter for removing any frequency or lower components and any frequency or higher components from the input signal and outputting only the frequencies within a predetermined frequency band. The band filter can also be configured by a combination of a low-pass filter and a high-pass filter. Therefore, in S38, the band filter can also be applied only in a predetermined frequency band region to achieve the driving sound of the EV mode.

[0051] In order to reflect changes in the dynamic performance of the vehicle in the EV driving sound control and achieve a sound that matches the driver's acceleration intention, a weight value can be applied to the virtual engine RPM (S32), and a weight value can also be applied to the opening degree of the accelerator pedal (S33).

[0052] In addition, the results of both S32 and S33 (S39) can be applied and selected. In addition, for vehicle speed data, the vehicle speed difference change value (S34) can be applied. The vehicle speed difference change value can be applied to the operation immediately before the output (S40), that is, the last operation of the signal processing controller 30.

[0053] Meanwhile, an algorithm for extracting the Nth-order component representing the characteristics and linearity of the motor output torque can be selectively determined according to the calculation speed, accuracy, calculation amount, etc.

[0054] Figure 5A and Figure 5B The case of applying the fast Fourier transform (FFT) algorithm, which has advantages in terms of accuracy, is shown. Figure 5A It is an exemplary view showing that time data is converted into frequency data, and FFT can be performed on the area that can be measured in a very short time, and the frequency resolution is low. Frequency resolution means the density of the values of the corresponding frequency bands that can be observed at intervals when observing a desired signal in the frequency domain. Therefore, the non-uniform fast Fourier transform (NFFT) technique can be additionally applied. By forcibly adding an additional M zero-padding data to increase the resolution, the original data information measured by the vibration sensor can be maintained. Finally, FFT data resampled to the 2Hz level can be obtained to extract the accurate value of the Nth-order component using the motor RPM. For this purpose, zero-padding up to the insufficient number of data can be performed by applying the NFFT technique, and the resolution can be resampled to the 2Hz level. Figure 5B The result of selectively obtaining only the data of the Nth component among the values extracted using the FFT analysis algorithm is shown.

[0055] The overall algorithm applying this algorithm includes: calculating the order component according to the vibration signal of the rotating EV motor, extracting the Nth-order component with the maximum linearity for the motor output torque among the calculated order components, calculating the frequency of each order component by converting the virtual RPM of the EV motor into frequency, setting the EV mode driving sound by applying the vibration level of the Nth-order component to the level of the frequency of each order component to be output, rearranging the order components, and outputting the set EV mode driving sound.

[0056] The extraction of the Nth-order component can control the driving sound of the EV motor of the EV based on the motor vibration for extracting the Nth-order component by performing FFT transformation on the vibration signal and performing resampling through NFFT.

[0057] Figure 6A 、 Figure 6B and Figure 6CThe result of extracting the Nth order component based on the virtual engine RPM information by applying the order tracking algorithm with a small amount of calculation using an algorithm for extracting the Nth order component representing the characteristics and linearity of the motor output torque is shown. Figure 6A In the above, the order components of the vibration signal are extracted by order tracking calculation, and in Figure 6B In , a band filter is applied to calculate the Nth order according to the change in the virtual engine RPM. The band filter is a bandpass filter and is a filter for removing any frequency or lower components and any frequency or higher components from an input signal and outputting only frequencies in a predetermined frequency band, and Figure 6B , the X-axis is frequency, and the Nth order component is extracted by applying a bandpass filter. Figure 6C is a diagram exemplarily showing the level of the Nth order component of the virtual engine RPM for each load.

[0058] The overall algorithm applying the algorithm can control the driving sound of the EV motor of the EV by calculating order components based on the vibration signal of the rotating EV motor, extracting the Nth order component among the calculated order components using order tracking analysis and an RPM-based bandpass filter for the EV motor, calculating the frequency of each order component by converting the RPM of the EV motor into a frequency, rearranging the order components by applying the vibration level of the Nth order component to the level of the frequency of each order component to be output, to set the EV mode driving sound, and outputting the set EV mode driving sound.

[0059] Figure 7 The virtual transmission signal and the change of the virtual gear number are shown. There is a change between the actual RPM of the EV motor and the RPM at the virtual gear 1-2-3-4 gear, and the virtual engine RPM is achieved so that a transmission delay occurs between the virtual target gear and the virtual current gear according to the change of the virtual gear number.

[0060] The virtual engine RPM is a reference for generating the overall virtual effect and is represented as in the following equation 1. In the instantaneous case, k may be determined by any one or more of the delay due to the connection between the virtual torque and the inertia, the transmission forward rate due to the clutch operation, and the virtual idle RPM, and in an ideal case, k may be 1.

[0061] The transmission forward rate is a reference for generating the transmission intervention torque, and is represented as the following Equation 2. When the virtual engine RPM follows the target gear RPM at the current gear RPM, the transmission forward rate is less than 100%, and when the virtual engine RPM is equal to the target gear RPM, the transmission forward rate completes 100%.

[0062] [Equation 1]

[0063] Virtual engine RPM = k × Measured actual motor RPM × Transmission ratio of virtual target stage

[0064] [Equation 2]

[0065] Transmission forward rate = (Virtual engine RPM - Current gear RPM) / (Target gear RPM - Current gear RPM) × 100%

[0066] Figure 8A and Figure 8B shows a comparison result before and after applying a virtual transmission signal and a virtual number of gear positions according to an exemplary embodiment of the present disclosure, and the comparison result is a change in frequency over time. This shows an order component that has a high correlation with the motor torque by extracting a vibration component, and generates a desired order component by using the motor RPM information, sets the level of the generated order component through an algorithm for synthesizing a vibration signal, and furthermore, in order to simulate the sound of an internal combustion engine during an accelerating drive, by additionally applying Figure 7 the virtual transmission signal, the frequency of the order component is changed over time according to the transmission mode generated by the virtual transmission signal.

[0067] In addition, terms related to a control device such as "controller", "control equipment", "control unit", "control device", "control module", or "server" refer to a hardware device including a memory and a processor configured to execute one or more steps interpreted as an algorithm structure. The memory stores algorithm steps, and the processor executes the algorithm steps to perform one or more processes of the method according to various exemplary embodiments of the present disclosure. The control device according to an exemplary embodiment of the present disclosure can be implemented by a non-volatile memory and a processor. The non-volatile memory is configured to store an algorithm for controlling the operation of each component of a vehicle or data on software commands for executing the algorithm, and the processor is configured to perform the above operations using the data stored in the memory. The memory and the processor can be separate chips. Alternatively, the memory and the processor can be integrated in a single chip. The processor can be implemented as one or more processors. The processor can include various logic circuits and operation circuits, can be configured to process data according to a program provided from the memory, and can be configured to generate a control signal according to the processing result.

[0068] The control device can be at least one microprocessor operated by a predetermined program, and the predetermined program can include a series of commands for performing the methods included in the above various exemplary embodiments of the present disclosure.

[0069] The foregoing invention may also be embodied as computer-readable code on a computer-readable recording medium. A computer-readable recording medium is any data storage device that can store data readable by a computer system later, as well as store and execute program instructions readable by a computer system later. Examples of computer-readable recordings include hard disk drives (HDDs), solid state drives (SSDs), silicon disk drives (SDDs), read-only memories (ROMs), random access memories (RAMs), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., as well as implementations as carrier waves (e.g., transmission via the Internet). Examples of program instructions include machine language code (such as machine language code generated by a compiler) and high-level language code executable by a computer using an interpreter, etc.

[0070] In various exemplary embodiments of the present disclosure, each of the above operations may be performed by a control device, and the control device may be configured by a plurality of control devices or an integrated single control device.

[0071] In various exemplary embodiments of the present disclosure, the memory and the processor may be provided as one chip or as separate chips.

[0072] In different exemplary embodiments of the present disclosure, the scope of the present disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) for enabling the operations of the methods according to different embodiments to be executed on a device or a computer, and non-transitory computer-readable media including such software or commands stored thereon and executable on a device or a computer.

[0073] In various exemplary embodiments of the present disclosure, the control device may be implemented in the form of hardware or software, or may be implemented in a combination of hardware and software.

[0074] Furthermore, terms such as "unit", "module", etc. included in the specification mean units for processing at least one function or operation, which may be implemented by hardware, software, or a combination thereof.

[0075] In an exemplary embodiment of the present disclosure, a vehicle may be referred to based on a concept including various transportation means. In some cases, a vehicle may be interpreted as based on not only various land transportation means traveling on roads (such as cars, motorcycles, trucks, and buses), but also various transportation means such as airplanes, drones, ships, etc.

[0076] For ease of explanation and to accurately define the appended claims, reference is made to the positions of such features shown in the accompanying drawings, and the terms "upper", "lower", "inner", "outer", "upward", "downward", "upward", "downward", "front", "rear", "rear", "inner", "outer", "inward", "outward", "inner", "outer", "inner", "outer", "forward" and "backward" are used to describe the features of the exemplary embodiments. It should be further understood that the term "connected" or its derivatives refer to both direct connection and indirect connection.

[0077] The term "and / or" may include combinations of multiple related listed items or any of the multiple related listed items. For example, "A and / or B" includes all three cases, namely "A", "B", and "A and B".

[0078] In an exemplary embodiment of the present invention, "at least one of A and B" may refer to "at least one of A or B" or "at least one of a combination of at least one of A and B". In addition, "one or more of A and B" may refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0079] In this specification, unless otherwise stated, singular expressions include plural expressions, unless the context clearly indicates otherwise.

[0080] In an exemplary embodiment of the present disclosure, it should be understood that terms such as "including" or "having" are intended to specify the presence of the features, quantities, steps, operations, elements, components, or combinations thereof described in the specification, and do not exclude the possibility of adding or the presence of one or more other features, quantities, steps, operations, elements, components, or combinations thereof.

[0081] According to an exemplary embodiment of the present invention, components may be combined with each other to form one, or some components may be omitted.

[0082] For purposes of illustration and description, the foregoing description of specific exemplary embodiments of the present disclosure has been presented. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. To illustrate certain principles of the present invention and their practical applications, exemplary embodiments have been selected and described so that other technicians in the art can make and utilize various exemplary embodiments of the present disclosure and their various alternatives and modifications. The scope of the present disclosure is intended to be defined by the appended claims and their equivalents.

Claims

1. A method for controlling the running sound of an electric vehicle using motor vibration and a virtual transmission signal, the method comprising: extracting, by a signal processing controller, a vibration level of an Nth order component having maximum linearity for motor output torque among order components extracted from a vibration signal of a rotating electric vehicle motor and a virtual engine rpm; determining, by the signal processing controller, a frequency of each order component by converting the revolutions per minute of the electric vehicle motor into a frequency; as well as The electric vehicle mode driving sound is set by the signal processing controller by applying the vibration level of the Nth order component to the level of the frequency of each order component to be output and rearranging the order components so that the virtual engine rpm reflects the driving mode changed according to the virtual gear number.

2. The method according to claim 1, wherein: The Nth order component is the coefficient of determination R 2 The Nth order component is more than 90%.

3. The method according to claim 1, wherein: The order components are determined by a vibration sensor that detects a vibration signal of the electric vehicle motor.

4. The method according to claim 1, wherein: The virtual engine rpm is determined by Equation 1, [Equation 1] Virtual engine rpm = actually measured motor rpm × virtual target gear ratio.

5. The method according to claim 1, wherein: For the virtual gear number, the difference between the virtual target gear and the virtual current gear is caused by the transmission forward rate of Equation 2, [Equation 2] Transmission forward rate = (virtual engine rpm - current gear rpm) / (target gear rpm - current gear rpm) x 100%.

6. The method according to claim 1, further comprising: Output the set electric vehicle mode driving sound, Wherein, before output, the output volume is adjusted by a signal processing controller by applying a frequency bandpass filter based on the revolutions per minute of the electric vehicle motor.

7. The method according to claim 1, further comprising: Output the set electric vehicle mode driving sound, Wherein, before outputting, the output volume is adjusted by applying a weight value to the revolutions per minute of the electric vehicle motor.

8. The method according to claim 1, further comprising: Output the set electric vehicle mode driving sound, Before output, the output volume is adjusted by applying a weight value to the pedal opening.

9. The method according to claim 1, further comprising: Output the set electric vehicle mode driving sound, Before outputting, the output volume is adjusted by determining the vehicle speed difference change value according to the vehicle speed data.

10. The method according to claim 1, wherein: In the setting of the electric vehicle mode running sound, an order component of a change according to the running mode is selectively set.

11. A method for controlling the running sound of an electric vehicle using motor vibration and a virtual transmission signal, the method comprising: extracting, by a signal processing controller, an Nth order component having maximum linearity for the motor output torque among order components extracted from a vibration signal of a rotating electric vehicle motor and a virtual engine rpm; determining, by the signal processing controller, a frequency of each order component by converting the revolutions per minute of the electric vehicle motor into a frequency; as well as The signal processing controller applies the vibration level of the Nth order component to the level of the frequency of each order component to be output and rearranges the order components to set the electric vehicle mode running sound, The virtual engine revolutions per minute are changed according to the virtual number of gears.

12. The method according to claim 11, wherein: Extracting the Nth order component includes performing fast Fourier transform on the vibration signal and resampling through unequal-interval fast Fourier transform.

13. The method according to claim 11, wherein: Extracting the Nth order component includes extracting the Nth order component using an order tracking analysis of the electric vehicle motor and a rpm based band pass filter.

14. A device for controlling the running sound of an electric vehicle using motor vibration and a virtual transmission signal, the device comprising: processor; as well as a non-transitory storage medium containing program instructions, The processor is configured to: extracting a vibration level of an Nth order component having maximum linearity for motor output torque from among order components extracted from a vibration signal of a rotating electric vehicle motor and a virtual engine rpm; determining a frequency of each order component by converting the revolutions per minute of the electric vehicle motor into a frequency; as well as An electric vehicle mode running sound is set by applying the vibration level of the Nth order component to the level of the frequency of each order component to be output and rearranging the order components so that the virtual engine rpm reflects the running mode converted according to the virtual gear number.

15. The device according to claim 14, wherein: The Nth order component is the coefficient of determination R 2 The Nth order component is more than 90%.

16. The device according to claim 14, wherein: The order component is determined by a vibration sensor that detects a vibration signal of the electric vehicle motor.

17. The device according to claim 14, wherein: The virtual engine rpm is determined by Equation 1, [Equation 1] Virtual engine rpm = actually measured motor rpm × virtual target gear ratio.

18. The device according to claim 14, wherein: For the virtual gear number, the difference between the virtual target gear and the virtual current gear is caused by the transmission forward rate of Equation 2, [Equation 2] Transmission advance rate = (virtual engine rpm - current gear rpm) / (target gear rpm - current gear rpm) × 100%.

19. The device according to claim 14, wherein: The processor is further configured to: output the set electric vehicle mode driving sound, Before output, the output volume is adjusted by applying a frequency bandpass filter based on the RPM of the electric vehicle motor, Before outputting, adjusting the output volume by applying a weight value to the revolutions per minute of the electric vehicle motor, Before output, adjust the output volume by applying a weight value to the pedal opening, or Prior to output, the output volume is adjusted by determining a vehicle speed difference change value based on the vehicle speed data.

20. The device according to claim 14, wherein: In the setting of the electric vehicle mode running sound, an order component of a change according to the running mode is selectively set.

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