Motor assembly gear noise optimization method and device

Abstract

The invention provides a motor assembly gear noise optimization method and device, and the method comprises the steps: injecting a voltage compensation instruction related to the noise order of a to-be-optimized gear under the working condition that the noise of the motor assembly gear exceeds the standard, and enabling a motor to generate a torque for suppressing the noise intensity of the gear. In the noise optimization target rotating speed section, according to the order of the gear to be optimized and the current motor rotating speed, the switching frequency is calculated; determining a voltage injection initial angle through theoretical analysis and calibration; according to the actual mechanical angle and the initial angle, a table is looked up to obtain a to-be-injected voltage instruction, and the table is obtained through theoretical analysis and calibration; superposing the to-be-injected voltage instruction on the original voltage instruction to obtain a target voltage instruction; and controlling the motor to generate torque for suppressing the gear noise intensity according to the switching frequency and the target voltage instruction. According to the method and device, the motor gear noise can be optimized by controlling the motor to generate the torque for suppressing the gear noise intensity, so that the cost is reduced, and the project period is prevented from being influenced.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a method and device for optimizing motor assembly gear noise. Background Art

[0002] In the drive system of electric vehicles, the motor assembly is a core component, and its performance directly affects the overall performance of the vehicle. In view of the different noise sources in the motor assembly, in the prior art, for the harmonic torque noise of each order caused by the motor, such as the 24th order, the 48th order, etc., the noise of a specific order is usually optimized by the harmonic current injection method based on the close relationship between the harmonic current and the harmonic torque. However, in practice, it is found that since there is no multiple relationship between the gear order and the electrical frequency, the traditional software control method is difficult to work. Therefore, the prior art usually reduces gear noise by optimizing the gear design, improving the tooth surface shape, or adjusting the noise conduction path. However, these methods need to be fully considered in the forward design. Once the gear design scheme is determined, if the noise is optimized, it involves the modification and verification of the scheme, which will greatly increase the cost and affect the entire project cycle. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method and device for optimizing the gear noise of a motor assembly, which can optimize the gear noise of the motor assembly by controlling the motor to generate a torque that suppresses the gear noise intensity, thereby reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle.

[0004] The first aspect of the present application provides a method for optimizing gear noise of a motor assembly, comprising:

[0005] Under the condition that the motor assembly gear noise exceeds the standard identified offline, the current motor speed, the gear order to be optimized and the original voltage command are obtained;

[0006] In the noise optimization target speed section, the switching frequency is calculated according to the gear order to be optimized and the current motor speed;

[0007] Determine the initial angle of voltage injection and collect the actual mechanical angle at each PWM control cycle point;

[0008] Determining a voltage instruction to be injected according to the actual mechanical angle and the initial angle;

[0009] Superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction;

[0010] The motor is controlled according to the switching frequency and the target voltage command to generate a torque that suppresses the intensity of gear noise.

[0011] Furthermore, the formula for calculating the switching frequency is:

[0012] Fpwm = k*Fgear*Fmech;

[0013] Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is a preset multiple coefficient, specifically an even multiple coefficient.

[0014] Further, determining the initial angle of voltage injection includes:

[0015] The initial angle of voltage injection is determined through theoretical analysis and calibration.

[0016] Further, determining the voltage instruction to be injected according to the actual mechanical angle and the initial angle includes:

[0017] Calculate the table lookup angle according to the initial angle and the actual mechanical angle;

[0018] Look up the table according to the table lookup angle to obtain a current instruction corresponding to the table lookup angle;

[0019] The voltage command to be injected is calculated according to the current command.

[0020] A second aspect of the present application provides a motor assembly gear noise optimization device, the motor assembly gear noise optimization device comprising:

[0021] An acquisition unit, used for acquiring the current motor speed, the gear order to be optimized and the original voltage command under the condition that the motor assembly gear noise exceeds the standard identified offline;

[0022] A calculation unit, used for calculating the switching frequency according to the gear order to be optimized and the current motor speed within the noise optimization target speed section;

[0023] A first determining unit, used to determine an initial angle of voltage injection;

[0024] The acquisition unit is used to acquire the actual mechanical angle at each PWM control cycle time point;

[0025] A second determining unit, configured to determine a voltage instruction to be injected according to the actual mechanical angle and the initial angle;

[0026] A superposition unit, used for superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction;

[0027] A control unit is used to control the motor to generate a torque that suppresses the intensity of gear noise according to the switching frequency and the target voltage command.

[0028] Furthermore, the formula for calculating the switching frequency is:

[0029] Fpwm = k*Fgear*Fmech;

[0030] Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is a preset multiple coefficient, specifically an even multiple coefficient.

[0031] Furthermore, the first determination unit is specifically configured to determine an initial angle of voltage injection through theoretical analysis and calibration.

[0032] Further, the second determining unit includes:

[0033] A calculation subunit, used for calculating a table lookup angle according to the initial angle and the actual mechanical angle;

[0034] A table lookup subunit, configured to perform a table lookup according to the table lookup angle to obtain a current instruction corresponding to the table lookup angle;

[0035] The calculation subunit is further used to calculate the voltage instruction to be injected according to the current instruction.

[0036] A third aspect of the present application provides an electronic device, comprising a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the motor assembly gear noise optimization method described in any one of the first aspect of the present application.

[0037] A fourth aspect of the present application provides a computer-readable storage medium storing computer program instructions, wherein when the computer program instructions are read and executed by a processor, the motor assembly gear noise optimization method described in any one of the first aspect of the present application is executed.

[0038] The beneficial effects of the present application are as follows: the method and device can optimize the motor assembly gear noise by controlling the motor to generate torque that suppresses the gear noise intensity, reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A schematic diagram of a flow chart of a method for optimizing motor assembly gear noise provided in an embodiment of the present application;

[0041] Figure 2 A schematic flow chart of another method for optimizing motor assembly gear noise provided in an embodiment of the present application;

[0042] Figure 3 A distance framework diagram of a motor assembly gear noise optimization method provided in an embodiment of the present application;

[0043] Figure 4 A schematic diagram of the structure of a motor assembly gear noise optimization device provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of the structure of another motor assembly gear noise optimization device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0046] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0047] Example 1

[0048] Please see Figure 1 , Figure 1 A schematic flow chart of a motor assembly gear noise optimization method provided in this embodiment. The motor assembly gear noise optimization method includes:

[0049] S101. Under the condition that the motor assembly gear noise exceeds the standard as identified offline, obtain the current motor speed, the gear order to be optimized, and the original voltage command.

[0050] S102: In the noise optimization target speed range, the switching frequency is calculated according to the gear order to be optimized and the current motor speed.

[0051] In this embodiment, the formula for calculating the switching frequency is:

[0052] Fpwm = k*Fgear*Fmech;

[0053] Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is the preset multiple coefficient, specifically an even multiple coefficient.

[0054] S103: Determine the initial angle of voltage injection, and collect the actual mechanical angle at each PWM control cycle time point.

[0055] S104: Determine a voltage instruction to be injected according to the actual mechanical angle and the initial angle.

[0056] S105 , superimposing the voltage command to be injected on the original voltage command to obtain a target voltage command.

[0057] S106 , controlling the motor to generate a torque that suppresses gear noise intensity according to the switching frequency and the target voltage command.

[0058] In this embodiment, the method can inject a signal that varies with space when the gear noise is excessive and is identified offline, so that the motor generates a torque that suppresses the intensity of the gear noise. Specifically, the method can inject a rectangular wave voltage command in an open loop by setting a specific switching frequency, and superimpose it on the original voltage command, thereby ultimately reducing the gear noise.

[0059] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0060] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0061] It can be seen that the implementation of the motor assembly gear noise optimization method described in this embodiment can optimize the motor assembly gear noise by controlling the motor to generate a torque that suppresses the gear noise intensity, thereby reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle.

[0062] Example 2

[0063] Please see Figure 2 , Figure 2 A schematic flow chart of a motor assembly gear noise optimization method provided in this embodiment. The motor assembly gear noise optimization method includes:

[0064] S201. Under the condition where the motor assembly gear noise exceeds the standard as identified offline, obtain the current motor speed, the gear order to be optimized, and the original voltage command.

[0065] S202: In the noise optimization target speed range, the switching frequency is calculated according to the gear order to be optimized and the current motor speed.

[0066] In this embodiment, the formula for calculating the switching frequency is:

[0067] Fpwm = k*Fgear*Fmech;

[0068] Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is the preset multiple coefficient, specifically an even multiple coefficient.

[0069] In this embodiment, the method can set the switching frequency (Fpwm) to an even multiple (k) of the gear order (Fgear) to be optimized within the noise optimization target speed range, that is, k is an even number. Specifically, the switching frequency also changes dynamically with the speed (corresponding to the mechanical frequency Fmech).

[0070] Generally, the following relationship exists: Fpwm=k*Fgear*Fmech.

[0071] S203. Determine the initial angle of voltage injection through theoretical analysis and calibration.

[0072] In this embodiment, the voltage injection initial angle refers to the initial angle of the rectangular wave voltage command to be injected, specifically the relative angle between the period starting point of the voltage waveform to be injected and the mechanical angle starting point. The initial angle value needs to be obtained through theoretical analysis and actual calibration.

[0073] S204: Collect the actual mechanical angle at each PWM control cycle time point.

[0074] In this embodiment, the method can calculate the mechanical angle at each PWM control cycle time point and convert it into the mechanical angle value required for voltage injection.

[0075] S205, calculating the table lookup angle according to the initial angle and the actual mechanical angle.

[0076] S206 , look up the table according to the table lookup angle to obtain a current instruction corresponding to the table lookup angle.

[0077] S207, calculating the voltage command to be injected according to the current command.

[0078] S208 , superimposing the voltage command to be injected on the original voltage command to obtain a target voltage command.

[0079] In this embodiment, the command of the injected voltage varies with space (mechanical angle). Specifically, the voltage command can be further simplified by looking up a table, wherein the input of the table is the angle and the output is the current (the voltage can be calculated according to the current and the rotation speed) command.

[0080] In this embodiment, the table lookup angle is processed as follows: table lookup angle = mod (mechanical angle - initial angle, 360 / Fgear).

[0081] In this embodiment, the first dimension of the table can be directly replaced by an array of [1:1:k]. The current command of the second dimension of the table can be an arbitrary waveform interpolation applicable to calibration, including but not limited to sine wave, triangle wave, rectangular wave, etc., and its amplitude is obtained through theoretical analysis and actual calibration.

[0082] S209, controlling the motor to generate a torque that suppresses gear noise intensity according to the switching frequency and the target voltage command.

[0083] Please see Figure 3 , Figure 3 A distance framework diagram of a motor assembly gear noise optimization method is shown. Wherein, UdUq represents the voltage component on the motor d-axis (direct axis) and the voltage component on the motor q-axis (quadrature axis).

[0084] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0085] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0086] It can be seen that the implementation of the motor assembly gear noise optimization method described in this embodiment can optimize the motor assembly gear noise by controlling the motor to generate a torque that suppresses the gear noise intensity, thereby reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle.

[0087] Example 3

[0088] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a motor assembly gear noise optimization device provided in this embodiment. Figure 3 As shown, the motor assembly gear noise optimization device includes:

[0089] The acquisition unit 310 is used to acquire the current motor speed, the gear order to be optimized and the original voltage command under the condition that the motor assembly gear noise exceeds the standard identified offline;

[0090] A calculation unit 320, used to calculate the switching frequency according to the gear order to be optimized and the current motor speed within the noise optimization target speed range;

[0091] A first determining unit 330, configured to determine an initial angle of voltage injection;

[0092] The acquisition unit 340 is used to acquire the actual mechanical angle at each PWM control cycle time point;

[0093] A second determining unit 350 is used to determine a voltage instruction to be injected according to the actual mechanical angle and the initial angle;

[0094] A superposition unit 360, used for superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction;

[0095] The control unit 370 is used to control the motor to generate a torque that suppresses the gear noise intensity according to the switching frequency and the target voltage command.

[0096] In this embodiment, the explanation of the motor assembly gear noise optimization device can refer to the description in Example 1 or Example 2, and will not be further elaborated in this embodiment.

[0097] It can be seen that the motor assembly gear noise optimization device described in this embodiment can optimize the motor assembly gear noise by controlling the motor to generate torque that suppresses the gear noise intensity, reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle.

[0098] Example 4

[0099] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a motor assembly gear noise optimization device provided in this embodiment. Figure 4 As shown, the motor assembly gear noise optimization device includes:

[0100] The acquisition unit 310 is used to acquire the current motor speed, the gear order to be optimized and the original voltage command under the condition that the motor assembly gear noise exceeds the standard identified offline;

[0101] A calculation unit 320, used to calculate the switching frequency according to the gear order to be optimized and the current motor speed within the noise optimization target speed range;

[0102] A first determining unit 330, configured to determine an initial angle of voltage injection;

[0103] The acquisition unit 340 is used to acquire the actual mechanical angle at each PWM control cycle time point;

[0104] A second determining unit 350 is used to determine a voltage instruction to be injected according to the actual mechanical angle and the initial angle;

[0105] A superposition unit 360, used for superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction;

[0106] The control unit 370 is used to control the motor to generate a torque that suppresses the gear noise intensity according to the switching frequency and the target voltage command.

[0107] In this embodiment, the formula for calculating the switching frequency is:

[0108] Fpwm = k*Fgear*Fmech;

[0109] Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is the preset multiple coefficient, specifically an even multiple coefficient.

[0110] As an optional implementation manner, the first determination unit 330 is specifically configured to determine the voltage injection initial angle through theoretical analysis and calibration.

[0111] As an optional implementation manner, the second determining unit 350 includes:

[0112] A calculation subunit 351, used to calculate the table lookup angle according to the initial angle and the actual mechanical angle;

[0113] The table lookup subunit 352 is used to look up the table according to the table lookup angle to obtain the current instruction corresponding to the table lookup angle;

[0114] The calculation subunit 351 is further used to calculate the voltage instruction to be injected according to the current instruction.

[0115] In this embodiment, the explanation of the motor assembly gear noise optimization device can refer to the description in Example 1 or Example 2, and will not be further elaborated in this embodiment.

[0116] It can be seen that the motor assembly gear noise optimization device described in this embodiment can optimize the motor assembly gear noise by controlling the motor to generate torque that suppresses the gear noise intensity, reducing the workload of gear design and tooth surface shape optimization in the later stage of the project, thereby greatly reducing costs and avoiding affecting the project cycle.

[0117] An embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the motor assembly gear noise optimization method in Embodiment 1 or Embodiment 2 of the present application.

[0118] An embodiment of the present application provides a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the motor assembly gear noise optimization method in Embodiment 1 or Embodiment 2 of the present application is executed.

[0119] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0120] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0121] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0122] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0123] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0124] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for optimizing motor assembly gear noise, characterized in that: include: Under the condition that the motor assembly gear noise exceeds the standard identified offline, the current motor speed, the gear order to be optimized and the original voltage command are obtained; In the noise optimization target speed section, the switching frequency is calculated according to the gear order to be optimized and the current motor speed; Determine the initial angle of voltage injection and collect the actual mechanical angle at each PWM control cycle point; Determining a voltage instruction to be injected according to the actual mechanical angle and the initial angle; Superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction; The motor is controlled according to the switching frequency and the target voltage command to generate a torque that suppresses the intensity of gear noise.

2. The motor assembly gear noise optimization method according to claim 1, characterized in that: The formula for calculating the switching frequency is: Fpwm = k*Fgear*Fmech; Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is a preset multiple coefficient, specifically an even multiple coefficient.

3. The motor assembly gear noise optimization method according to claim 1, characterized in that: The determining of the initial angle of voltage injection comprises: The initial angle of voltage injection is determined through theoretical analysis and calibration.

4. The motor assembly gear noise optimization method according to claim 3, characterized in that: The step of determining the voltage instruction to be injected according to the actual mechanical angle and the initial angle includes: Calculate the table lookup angle according to the initial angle and the actual mechanical angle; Look up the table according to the table lookup angle to obtain a current instruction corresponding to the table lookup angle; The voltage command to be injected is calculated according to the current command.

5. A motor assembly gear noise optimization device, characterized in that: The motor assembly gear noise optimization device comprises: An acquisition unit, used for acquiring the current motor speed, the gear order to be optimized and the original voltage command under the condition that the motor assembly gear noise exceeds the standard identified offline; A calculation unit, used for calculating the switching frequency according to the gear order to be optimized and the current motor speed within the noise optimization target speed section; A first determining unit, used to determine an initial angle of voltage injection; The acquisition unit is used to acquire the actual mechanical angle at each PWM control cycle time point; A second determining unit, configured to determine a voltage instruction to be injected according to the actual mechanical angle and the initial angle; A superposition unit, used for superimposing the voltage instruction to be injected on the original voltage instruction to obtain a target voltage instruction; A control unit is used to control the motor to generate a torque that suppresses the intensity of gear noise according to the switching frequency and the target voltage command.

6. The motor assembly gear noise optimization device according to claim 5, characterized in that: The formula for calculating the switching frequency is: Fpwm = k*Fgear*Fmech; Among them, Fpwm is the switching frequency, Fgear is the gear order to be optimized, Fmech is the mechanical frequency corresponding to the current motor speed, and k is a preset multiple coefficient, specifically an even multiple coefficient.

7. The motor assembly gear noise optimization device according to claim 5, characterized in that: The first determination unit is specifically configured to determine an initial angle of voltage injection through theoretical analysis and calibration.

8. The motor assembly gear noise optimization device according to claim 7, characterized in that: The second determining unit includes: A calculation subunit, used for calculating a table lookup angle according to the initial angle and the actual mechanical angle; A table lookup subunit, configured to perform a table lookup according to the table lookup angle to obtain a current instruction corresponding to the table lookup angle; The calculation subunit is further used to calculate the voltage instruction to be injected according to the current instruction.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the motor assembly gear noise optimization method according to any one of claims 1 to 4.

10. A readable storage medium, characterized in that: The readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the motor assembly gear noise optimization method according to any one of claims 1 to 4 is executed.

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