Method and system for controlling interior sound of a vehicle

Abstract

The present disclosure relates to a system for controlling the interior sound of a vehicle. The system phase-shifts the frequency of extraneous sound generated by the engine's operating state to increase current density, thereby suppressing signal distortion. This reduces or minimizes distortion caused by excessive amplifier current usage when generating extraneous sound, and suppresses the generation of unnecessary noise in a vibration generator and the vehicle's frame.

Description

Technical Field

[0001] The present disclosure relates to a method and system for controlling interior sound of a vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Recently, the development of new technologies for electric and hybrid vehicles has been ongoing both domestically and internationally. Drivers may be unaware of the driving experience, which can lead to accidents. Therefore, electric and hybrid vehicles should meet minimum noise standards while driving.

[0004] Furthermore, in addition to electric vehicles and hybrid vehicles, even ordinary vehicles generate engine sounds and exhaust sounds as well as additional running sounds when traveling at high speeds to create a sporty driving feeling when traveling at high speeds.

[0005] The driving sound is generated separately by analyzing the engine speed, engine torque, vehicle speed and the position of the accelerator pedal, and generating sound as the driving sound inside the vehicle through a vibration generator according to the driving state of the vehicle.

[0006] This vibration generator is provided with an amplifier for increasing the power of a signal. However, due to the characteristics of the amplifier itself, current distortion occurs in a specific area.

[0007] In other words, when generating driving sounds, an algorithm based on driving conditions generates a digital signal according to the given situation. This digital signal is converted into an analog signal, and then the analog signal is amplified according to the actual current. When the vehicle enters the high RPM range, excessive current usage in the amplifier causes distortion, generating harmonic components and producing unwanted noise in the vibration generator and vehicle body.

[0008] The above content is only intended to help understand the background of the present disclosure, and is not intended to indicate that the present disclosure falls within the scope of the prior art known to those skilled in the art. Summary of the Invention

[0009] The present disclosure provides a method and system for controlling the interior sound of a vehicle. Specifically, the method and system are configured to reduce or minimize distortion that may occur due to excessive amplifier current usage when generating additional sound, thereby suppressing or preventing unnecessary noise from a vibration generator and vehicle body.

[0010] In one form of the present disclosure, a method for controlling interior sound of a vehicle is provided, the method being configured to transmit additional sound corresponding to engine sound and exhaust sound of the vehicle to the interior of the vehicle, the method comprising: a controller analyzing a plurality of orders having different frequencies based on an engine operating state; the controller applying a pre-stored phase signal for correction to one or more of the plurality of orders; and the controller synthesizing the orders to which the pre-stored phase signal for correction is applied to output a drive signal for generating the additional sound.

[0011] In one form, applying the pre-stored phase signal for correction may include: grouping a plurality of orders based on orders consistent with a period of a signal waveform according to frequency; and applying the pre-stored phase signal for correction to each group.

[0012] In another form, applying the pre-stored phase signal for correction may include grouping orders that coincide with one another according to a greatest common divisor of frequencies of the orders.

[0013] In other forms, synthesizing the orders may include synthesizing the orders of each group using pre-stored phase signals for correction.

[0014] The phase of the pre-stored phase signal for correction may be set in each group so that a maximum current amplitude and a minimum current amplitude of a frequency band based on an order of each group are less than or equal to a preset current value.

[0015] The pre-stored phase signal for correction can derive the maximum current amplitude and the minimum current amplitude by deriving values ​​according to which the differential coefficients in the frequency band of some orders among the multiple orders become zero, and the maximum current amplitude and the minimum current amplitude can be derived as phase values ​​less than or equal to the preset current value.

[0016] In one form, when synthesizing the orders, after synthesizing the orders of each group, a preset gain value is applied to output a driving signal for the additional sound.

[0017] In another aspect of the present disclosure, a system for controlling interior sound of a vehicle is provided. The system is configured to transmit additional sound corresponding to the engine sound and exhaust sound of the vehicle to the interior of the vehicle. The system may include: a sound module configured to transmit the additional sound based on the engine operating state; and a controller configured to control the additional sound of the sound module. Specifically, the controller analyzes multiple orders having different frequencies based on the engine operating state, applies a pre-stored phase signal for correction to one or more of the multiple orders, and synthesizes the orders of the multiple orders to which the pre-stored phase signal for correction is applied to output a drive signal for generating the additional sound, thereby causing the sound module to transmit the additional sound as the drive signal.

[0018] The controller may group the orders of the plurality of orders based on frequency, and may apply a pre-stored phase signal for correction to each group.

[0019] The controller can group orders with consistent periods according to frequency, and can be divided into multiple groups.

[0020] The controller may synthesize the order of each group applying a pre-stored phase signal for correction.

[0021] The pre-stored phase signal for correction may be a phase set for each group so that when the order of each group is synthesized, the maximum current amplitude and the minimum current amplitude of the frequency band are less than or equal to a preset current value.

[0022] After synthesizing the orders of each group, the controller may apply a preset gain value to output a driving signal for the additional sound.

[0023] The method and system for controlling the interior sound of a vehicle, configured as described above, can phase-shift the frequency of the additional sound generated based on the engine's operating state to increase current density, thereby suppressing or preventing signal distortion. Consequently, the present disclosure can effectively suppress distortion caused by excessive amplifier current when generating additional sound, thereby preventing unnecessary noise from being generated in the vibration generator and the vehicle's frame.

[0024] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order that the present disclosure may be fully understood, various forms of the present disclosure will be described by way of example with reference to the accompanying drawings, in which:

[0026] Figure 1 and Figure 2is a flow chart illustrating a method of controlling interior sound of a vehicle;

[0027] Figure 3 is a graph showing frequency according to engine speed;

[0028] Figure 4 and Figure 5 is shown for illustration purposes only. Figure 1 A graph illustrating the phase of the method for controlling interior sound of a vehicle;

[0029] Figure 6 It shows Figure 1 A flowchart of a method of controlling interior sound of a vehicle is shown; and

[0030] Figure 7 is a schematic diagram of a system for controlling the interior sound of a vehicle.

[0031] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0032] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate identical or corresponding parts and features.

[0033] Hereinafter, a method and system for controlling interior sound of a vehicle according to exemplary forms of the present disclosure are described with reference to the accompanying drawings.

[0034] Figure 1 and Figure 2 is a flow chart illustrating a method of controlling interior sound of a vehicle according to one form of the present disclosure, Figures 3 to 6 Is used to illustrate Figure 1 A view of a method of controlling interior sound of a vehicle is shown, Figure 7 is a schematic diagram of a system for controlling interior sound of a vehicle according to one form of the present disclosure.

[0035] like Figures 1 to 3 As shown, the method for controlling the interior sound of a vehicle includes: a confirmation step S10 of analyzing a plurality of orders having different frequencies based on an engine operating state; a correction step S20 of applying a pre-stored phase signal for correction to one or more of the plurality of orders; and an output step S30 of synthesizing the plurality of orders to which the phase signal for correction is applied, and outputting it as a driving signal for generating an additional sound.

[0036] In one form, in order to generate additional sounds corresponding to engine sounds and exhaust sounds inside the vehicle, a speaker may be provided that emits sounds similar to the engine sounds or exhaust sounds through an electrical signal based on the engine operating state.

[0037] The present disclosure aims to reduce or minimize the phenomenon of current distortion caused by the characteristics of the amplifier itself, wherein the amplifier generates an electrical signal for the speaker, which produces additional sound. To this end, a microcontroller unit (MCU) receives a controller area network (CAN) signal based on the engine's operating status and generates a sound waveform according to the situation through a preset algorithm. A digital-to-analog converter (DAC) converts the digital signal based on the sound waveform into an analog signal, and the analog signal is amplified by an amplifier (AMP) to match the actual current. Here, the current distortion phenomenon occurs due to the characteristics of the amplifier itself. The present disclosure reduces the harmonic components caused by the distortion phenomenon, thereby improving the problem of generating rattling noise.

[0038] Specifically, a confirmation step S10 is performed in which a plurality of orders having different frequencies based on the engine operating state are analyzed. Here, the engine operating state may be the engine speed (RPM) and the engine load, and a change in the engine frequency according to the engine speed is analyzed. In addition, the order is a frequency component that generates a vibration excitation force based on the engine speed. For example, Figure 3 As shown, orders C2, C3, ..., C(n) are set according to the engine frequency based on the engine speed, and different frequencies are analyzed for each order. That is, in confirmation step S10, orders based on the engine speed are pre-stored, and frequencies are analyzed for each order. The orders can be set based on the characteristics of the speaker and amplifier, as well as the engine specifications, and the frequencies based on the orders can be derived and stored in advance.

[0039] As described above, when multiple orders are analyzed in the confirmation step S10, the correction step S20 is performed, in which a pre-stored phase signal for correction is applied to one or more orders. That is, the current in the frequency band can be reduced by applying the pre-stored phase signal for correction to the frequencies according to the multiple orders.

[0040] Here, in the correction step S20, a plurality of orders may be grouped based on the order of the same period of the synthesized signal according to the frequency, and a pre-stored phase signal for correction may be applied to each group. Subsequently, the output step S30 may synthesize the order of each group to which the phase signal for correction is applied in the correction step S20.

[0041] Therefore, each phase signal for correction can be applied to multiple orders. However, storing all the phase signals for correction corresponding to each order requires a large storage space. Therefore, it is necessary to group the multiple orders so that the period of the synthesized signal according to the frequency is consistent, and apply the phase signal for correction to each group.

[0042] In the correction step S20, the signal periods of each group are made consistent, thereby enabling the groups to be divided into multiple groups. As described above, when grouping the orders, only when the periods based on frequency are consistent can the optimized value be derived by applying and synthesizing the phase signal used for correction. Therefore, it is necessary to make the periods consistent when grouping the orders.

[0043] Therefore, by grouping multiple orders to align the periods of the synthesized signals according to frequency and applying a phase correction signal to each group, the frequency shape of each group remains the same, and the amplitudes of the maximum and minimum currents in the frequency band can be adjusted during synthesis. Thus, in the present disclosure, distortion caused by excessive current in the amplifier can be prevented by adjusting the current amplitudes in the frequency band.

[0044] The phase signal used for correction can also be phase-set for each group so that, when the orders of each group are synthesized, the maximum and minimum current amplitudes of the frequency band are less than or equal to a preset current value. The preset current value is intended to prevent current distortion and rattling noise, and can be determined in advance through experimentation.

[0045] Specifically, to derive the maximum and minimum current amplitudes, the phase signal for correction according to the frequency of the order is obtained by finding the position where the differential coefficient (slope) becomes zero in the frequency (sinusoidal waveform) according to each order. In this case, when deriving the phase signal for correction, by deriving a value where the differential coefficient is zero in a frequency band according to some of the multiple orders, without examining all the frequencies of the orders, it is possible to derive the maximum and minimum current amplitudes that can be grouped using only a portion.

[0046] In other words, if f(t) = Asin(2πf1t) + Bsin(2πf2t) + Csin(2πf3t) is differentiated assuming three orders, it can be calculated as f′(t) = A(2πf1)cos(2πf1t) + (2πf2)cos(2πf2t) + C(2πf3)sin(2πf3t), thereby deriving the value of f′(t) = 0. Where A is the maximum amplitude, f is the frequency, and t is the time.

[0047] Thus, the maximum current amplitude and the minimum current amplitude can be derived by using a portion of values ​​according to time without checking all frequencies, and a portion of values ​​can be utilized according to a period of time within a cycle.

[0048] Using this calculation, the phase signal for correction can be derived by the following equation.

[0049]

[0050] This equation can be differentiated as follows:

[0051]

[0052] Here, the phase may be a phase signal, and the phase signal for correction may be obtained by deriving the phase included in the preset current value when f′(t) is 0.

[0053] That is, Figure 4 As shown in FIG, when there are groups A, B, and C with different cycles, it can be seen that the current of the waveform synthesized for each group exceeds 1A, which is an appropriate value of the amplifier characteristics, and reaches 2A. Figure 5 As shown, when the phase signals for correction corresponding to Groups B and C are applied, the present disclosure can show that the current synthesized into the waveform of each group is less than 1 A. As described above, when the phase signal for correction is applied to each group, the current density increases over time, and by utilizing this principle, the current distortion due to the amplifier characteristics is reduced or minimized.

[0054] Reference Figure 4 and Figure 5 , the frequency based on each group and the phase signal for correction are exemplary, and various values ​​may be applied in consideration of various factors.

[0055] At the same time, after synthesizing the order of each group, the output step S30 may apply a preset gain value to output a driving signal for the additional sound. This step is to output a driving signal for the speaker for the additional sound output, and after synthesizing the order of each group, the amplifier output value may be derived by multiplying the gain value and the synthesized signal.

[0056] Here, the gain value is based on the driving condition of the vehicle, and application of the gain value is intended to form an additional sound that is the same as the engine sound according to various driving conditions taking into account RPM, engine torque, vehicle speed, etc. Therefore, an additional sound suitable for the driving condition of the vehicle can be output through the speaker according to the output value of the amplifier.

[0057] like Figure 6 As shown, in one form of the present disclosure as described above, the control method of the present disclosure is as follows.

[0058] In one form, the method performs step S11 of collecting information based on the engine operating state. This step enables the MCU to receive engine operating state information such as engine speed (RPM) and engine load from various sensors as CAN signals, and generate a sound waveform according to the situation through a preset algorithm.

[0059] Thereafter, the digital signal may be converted into an analog signal by a DAC, and a grouping step S12 may be performed based on frequency data according to a plurality of orders. In this case, each group may group orders whose cycles of the synthesized signal according to the frequency coincide with each other, and a step S21 of applying each phase signal for correction to each group may be performed. Figure 3 In FIG. 5 , assuming that there are three groups and a phase signal for correction corresponding to each group, it can be seen that step S22 of applying each phase signal for correction to each group is performed.

[0060] As described above, when the phase signal for correction is applied to each group, step S31 of synthesizing the groups to which the phase signal for correction is applied is performed, and then step S32 of applying the gain value after synthesizing the groups is performed. As described above, when the gain value is applied, step S33 of outputting the driving signal for the additional sound is performed, so that the additional sound can be generated as the driving signal for the final output by the sound module.

[0061] At the same time, if Figure 7 As shown, a system for controlling the interior sound of a vehicle transmits additional sound corresponding to the engine sound and exhaust sound of the vehicle to the interior of the vehicle, and the system for controlling the interior sound of the vehicle includes: a sound module 10 for transmitting the additional sound based on the engine operating state; and a controller 20, wherein the controller is configured to control the additional sound of the sound module 10, and analyze a plurality of orders having different frequencies based on the engine operating state and apply a pre-stored phase signal for correction to one or more of the plurality of orders by synthesizing the plurality of orders, and output a driving signal for generating the additional sound, so that the sound module 10 transmits the additional sound as the driving signal.

[0062] Here, the sound module 10 may be a speaker that generates additional sound by vibrating based on the engine's operating status. The controller 20 may be equipped with an MCU, a DAC, and an amplifier. The MCU receives a signal input based on the engine's operating status and generates a sound waveform based on the situation using a preset algorithm. The DAC converts the digital signal based on the sound waveform into an analog signal, and the amplifier amplifies the analog signal to match the actual current. Furthermore, the controller 20 is configured to control the sound module 10.

[0063] In other words, since the controller 20 analyzes orders based on the engine operating state and performs phase change to apply a pre-stored phase signal for correction to each order, a waveform of a frequency below a predetermined current is generated, thereby increasing current density and avoiding the rattling problem.

[0064] Here, the controller 20 groups multiple orders based on the order of the same period of the synthesized signal according to the frequency. In this case, the controller 20 can divide the signal into multiple groups so that the signal period of each group is consistent, and can apply a pre-stored phase signal for correction to each group. Here, the controller 20 can perform grouping based on the frequency of the multiple orders, and can pre-derive the frequencies of the multiple orders and store them in the controller 20. Thereafter, the controller 20 can synthesize the orders of each group to which the phase signal for correction is applied.

[0065] Here, when synthesizing the order of each group, the phase signal preset by the controller 20 may be set at a phase in which the maximum current amplitude and the minimum current amplitude of each group with respect to the frequency band are less than or equal to a preset current value.

[0066] In addition, the controller 20 may output a driving signal for the additional sound by applying a preset gain value after synthesizing the order of each group.

[0067] Therefore, additional sound suitable for the driving condition of the vehicle can be output through the speaker according to the output value of the amplifier.

[0068] The controller 20 according to an exemplary form of the present disclosure can be implemented by a non-volatile memory (not shown) and a processor (not shown), wherein the non-volatile memory is configured to store data related to algorithms developed to control the operation of various components of the vehicle or software instructions for reproducing the algorithms, and the processor is configured to use the data stored in the memory to perform the operations described below. Here, the memory and the processor can be implemented as separate chips. Alternatively, the memory and the processor can be implemented as a single chip integrated with each other. The processor can adopt a configuration having one or more processors.

[0069] The method and system for controlling the interior sound of a vehicle, configured as described above, can phase-shift the frequency of the additional sound generated based on the engine's operating state to increase current density, thereby preventing signal distortion. This reduces or minimizes distortion caused by excessive amplifier current when generating the additional sound, and suppresses or prevents the generation of unnecessary noise in the vibration generator and vehicle body.

[0070] As described above, the present disclosure has been described with reference to specific exemplary forms. However, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from the scope and spirit of the present disclosure.

Claims

1. A method of controlling interior sound of a vehicle, the method transmitting additional sound corresponding to engine sound and exhaust sound of the vehicle to the interior of the vehicle, the method comprising: Controller analysis has multiple orders with different frequencies based on engine operating conditions; The controller applies a pre-stored phase signal for correction to one or more orders of the plurality of orders; as well as The controller synthesizes the plurality of orders applying the pre-stored phase signal for correction to output a driving signal for generating the additional sound, in, Applying the pre-stored phase signal for correction includes: grouping the plurality of orders into at least one group based on at least one of the plurality of orders having consistent cycles of signal waveforms according to frequencies; and applying the pre-stored phase signal for correction to at least one group including the at least one order; wherein synthesizing the plurality of orders comprises synthesizing at least one order of at least one group of the pre-stored phase signals for correction, The phase of the pre-stored phase signal for correction is set in at least one group so that the maximum current amplitude and the minimum current amplitude of the at least one frequency band of each order based on the at least one group are less than or equal to a preset current value, and The pre-stored phase signal for correction is derived by deriving a value at which a differential coefficient becomes zero in a frequency band according to at least one order of the multiple orders to derive the maximum current amplitude and the minimum current amplitude, and deriving the maximum current amplitude and the minimum current amplitude as phase values ​​less than or equal to the preset current value.

2. The method according to claim 1, wherein Applying the pre-stored phase signal for correction includes: The plurality of orders that coincide with each other according to the greatest common divisor of the frequencies of the plurality of orders are grouped.

3. The method according to claim 1, wherein In synthesizing the plurality of orders, after synthesizing the at least one order of at least one group, a preset gain value is applied to output the driving signal for the additional sound.

4. A system for controlling interior sound of a vehicle, the system transmitting additional sound corresponding to engine sound and exhaust sound of the vehicle to the interior of the vehicle, the system comprising: a sound module that transmits the additional sound based on the engine operating status; as well as a controller that controls the additional sound of the sound module, analyzes a plurality of orders having different frequencies based on an operating state of the engine, applies a pre-stored phase signal for correction to the plurality of orders, and synthesizes the plurality of orders to which the pre-stored phase signal for correction is applied to output a drive signal for generating the additional sound, thereby causing the sound module to transmit the additional sound as the drive signal; in, Applying the pre-stored phase signal for correction includes: grouping the plurality of orders into at least one group based on at least one of the plurality of orders having consistent cycles of signal waveforms according to frequencies; and applying the pre-stored phase signal for correction to at least one group including the at least one order; wherein synthesizing the plurality of orders comprises synthesizing at least one order of at least one group of the pre-stored phase signals for correction, The phase of the pre-stored phase signal for correction is set in at least one group so that the maximum current amplitude and the minimum current amplitude of the at least one frequency band of each order based on the at least one group are less than or equal to a preset current value, and The pre-stored phase signal for correction is derived by deriving a value at which a differential coefficient becomes zero in a frequency band according to at least one order of the multiple orders to derive the maximum current amplitude and the minimum current amplitude, and deriving the maximum current amplitude and the minimum current amplitude as phase values ​​less than or equal to the preset current value.

5. The system according to claim 4, wherein: The controller makes the periods of the signals of at least one group including at least one order consistent, and the periods of the signals are divided into a plurality of groups.

6. The system according to claim 4, wherein: After synthesizing the at least one order of at least one group, the controller applies a preset gain value to output the driving signal for the additional sound.

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