Noise reduction method and device for automobile multi-motor system and automobile

Abstract

The invention relates to a noise reduction method and device for an automobile multi-motor system, a storage medium and a vehicle. The method comprises the steps that when a first motor and a second motor are both in a running state, the noise frequency and state parameters of the first motor and the noise frequency and state parameters of the second motor are obtained; according to the specific frequency parts of the two motors, harmonic current acting on the other motor is generated in combination with the state parameters of the other motor; and for the common frequency part of the two motors, the phases of the first motor and the second motor on the common noise frequency are controlled to be opposite based on a conventional mode. Compared with the prior art, noise reduction is achieved through pairing of the two motors, the unique frequency and the common frequency are processed respectively, the frequency range capable of being subjected to noise reduction can be greatly widened, and then the vehicle noise is better reduced.

Description

Technical Field

[0001] The present invention relates to the field of electric drive, and in particular to a noise reduction method, device, storage medium and vehicle for a multi-motor system of an automobile. Background Art

[0002] New energy vehicles are the key to the transformation and upgrading of my country's automobile industry. The main common types are: hybrid vehicles that take into account both endurance and fuel economy, electric vehicles with dual motors as main drive and auxiliary drive, and wheel-side and wheel-hub drive vehicles with two or four wheels that can be driven independently and flexibly controlled. The corresponding electric drive systems are as follows: (1) hybrid systems with generators and drive motors, (2) main drive and auxiliary drive systems with dual motors, (3) wheel-side and wheel-hub motor systems with two independent wheels. (4) wheel-side and wheel-hub motor systems with four independent wheels. Among them, (1), (2) and (3) have two motor systems, and (4) has four motor systems. All of the above drive systems have multiple motor systems. When multiple motors work together, multiple noise sources couple with each other, making the superposition of noise inside the vehicle more intense. The noise is one after another, which reduces the ride comfort of the new energy vehicle.

[0003] To solve the problem of noise from multiple motor systems in new energy vehicles being superimposed and increasing, the existing methods for reducing vibration and noise are as follows: (1) Generally, the physical hardware of each motor is optimized separately, such as improving the material stiffness from the design perspective, or improving the manufacturing accuracy from the process perspective to reduce vibration and noise. These optimization methods will increase the material cost and manufacturing cost. (2) Equip the car with an ANC (Active Noise Control) system, which generates anti-phase sound waves in the audio generator in the car to offset the noise of the hybrid system, but this will greatly increase the hardware cost of the whole vehicle. In addition, according to the noise transfer theory of "source-path-receiver", equipping the car with an ANC system only solves the problem at the receiver end, and does not really solve the problem from the source of noise, so the actual experience is not ideal.

[0004] There are also some existing technologies that attempt to reduce noise by injecting current. For example, Chinese patent CN108386280A discloses a noise reduction method for a vehicle, which is used to actively reduce the noise of the vehicle's range extender. The vehicle includes a range extender, which includes an engine module and a generator module. The noise reduction method includes setting the corresponding relationship between the power and speed of the range extender and the combustion parameters of the engine module; adjusting the phase of the sound generated by the engine and the generator module so that the frequency of the sound they generate is the same and the phase is opposite; controlling the amplitude of the sound with opposite phases of the engine module and the generator module to cancel each other. The noise reduction system includes an engine module and a generator module; wherein the engine module and the generator module are configured to have opposite phases of the sound generated within the same frequency during operation, so that the amplitude of their sound cancels each other. However, the frequency range overlap interval of the engine and the range extender is small, so this solution can only eliminate noise in certain specific frequency intervals, and it is difficult to meet the demand for eliminating the overall noise of the vehicle. Summary of the invention

[0005] The purpose of the present invention is to provide a noise reduction method, device, storage medium and vehicle for a multi-motor system of an automobile, which realizes noise reduction by pairing two motors and processes the unique frequency and the common frequency separately, which can greatly increase the frequency range that can be reduced, thereby better reducing vehicle noise.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A noise reduction method for a multi-motor system of an automobile, comprising:

[0008] When the first motor and the second motor paired with the first motor are both in a running state, obtaining the noise frequency of the first motor and the state parameter of the corresponding second motor, wherein the corresponding second motor is the second motor paired with the first motor;

[0009] A portion of the noise frequency of the first motor that is within a first frequency range is extracted as a first characteristic noise frequency, and a second harmonic current acting on the corresponding second motor is generated based on the first characteristic noise frequency and a state parameter of the corresponding second motor, wherein the first frequency range is a frequency range unique to the first motor.

[0010] Furthermore, in order to provide a noise reduction effect, a scheme is added in which the first motor is used to reduce the noise of the unique frequency part of the second motor. Specifically, the noise reduction method further includes:

[0011] When the first motor and the second motor paired with the first motor are both in a running state, obtaining a state parameter of the first motor and a noise frequency corresponding to the second motor;

[0012] A portion of the noise frequency corresponding to the second motor that is within a second frequency range is extracted as a second characteristic noise frequency, and a first harmonic current acting on the first motor is generated based on the second characteristic noise frequency combined with a state parameter of the first motor, wherein the second frequency range is a frequency range unique to the second motor.

[0013] Furthermore, a noise reduction scheme for the noise of the common frequency portion of the first motor and the second motor is added, and the noise reduction method further includes:

[0014] A portion of the noise frequency of the first motor that is within the third frequency range is extracted as a first common noise frequency, a portion of the noise frequency of the corresponding second motor that is within the third frequency range is extracted as a second common noise frequency, and based on the first common noise frequency and the second common noise frequency, the first motor and the corresponding second motor are controlled to have opposite phases on the common noise frequency, wherein the third frequency range is a frequency range common to the first motor and the corresponding second motor.

[0015] The state parameters of the second motor include the rotation speed and the number of pole pairs of the second motor;

[0016] The second harmonic current acting on the corresponding second motor is generated based on the first characteristic noise frequency combined with the state parameters of the corresponding second motor, specifically: the second harmonic current acting on the corresponding second motor is generated according to the first characteristic noise frequency combined with the rotational speed and pole pair number of the corresponding second motor.

[0017] The order of the second harmonic current is specifically:

[0018]

[0019] Among them: B is the order of the second harmonic current, f A is the first characteristic noise frequency, n B is the speed of the second motor, p B is the number of pole pairs of the second motor.

[0020] The state parameters of the first motor include the rotation speed and the number of pole pairs of the first motor;

[0021] The method of generating the first harmonic current acting on the first motor based on the second characteristic noise frequency combined with the state parameters of the first motor is specifically: generating the first harmonic current acting on the first motor based on the second characteristic noise frequency combined with the rotation speed and pole pair number of the first motor.

[0022] The first harmonic current order is specifically:

[0023]

[0024] Among them:A is the order of the first harmonic current, f B is the second unique noise frequency, n A is the speed of the first motor, p A is the number of pole pairs of the first motor.

[0025] There are one or more first motors and one or more second motors, and the number of the first motors and the second motors are equal and matched one by one.

[0026] A noise reduction device for a multi-motor system of an automobile comprises a memory, a processor, and a program stored in the memory, wherein the processor implements the above method when executing the program.

[0027] The first motor and the second motor paired therewith are both provided with acoustic corrugated plates, and the phases of the acoustic corrugated plates thereon are opposite.

[0028] A hybrid vehicle includes a vehicle body, a drive motor and a generator, and is characterized in that it also includes a noise reduction device as described above, and the drive motor is defined as a first motor, and the generator is defined as a second motor paired with the first motor.

[0029] A multi-drive motor vehicle comprises a vehicle body and multiple drive motors, and is characterized in that it also comprises a noise reduction device as described above, wherein the number of the drive motors is an even number, any drive motor is defined as a first motor, and a drive motor symmetrically arranged on the other side of the vehicle with the first motor is defined as a second motor paired with the first motor.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. Use two motors to achieve noise reduction, and process the unique frequency and common frequency separately, which can greatly increase the frequency range that can be reduced, thereby better reducing vehicle noise.

[0032] 2. The number of times harmonic currents are generated based on their own speed and pole pair number can reduce the requirements for the computing power of the control system. There is no need to conduct experiments to determine the comparison relationship table for various scenarios. When the motor structure is modified, there is no need to re-test to obtain the comparison relationship table, which greatly reduces costs.

[0033] 3. It has good applicability to hybrid vehicles and multi-motor systems.

[0034] 4. The noise reduction effect is better by using the noise source. Compared with the ANC audio generator in the car which only weakens the noise at the receiver, the noise reduction effect is better by using the noise source. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic flow chart of the main steps of the method in Example 1 of the present invention;

[0036] Figure 2 Schematic diagram of the main steps of the method in Example 4 of the present invention. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] Example 1

[0039] For hybrid vehicles, the hybrid vehicle includes a vehicle body, a drive motor and a generator, the drive motor and the generator constitute a dual-motor system, the drive motor is defined as the first motor, the generator is defined as the second motor paired with the first motor, and the noise reduction method designed for the automotive multi-motor system includes:

[0040] When the first motor and the second motor paired with the first motor are both in a running state, obtaining the noise frequency and state parameters of the first motor, and the noise frequency and state parameters of the second motor;

[0041] Extracting a portion of the noise frequency of the first motor that is in a first frequency range as a first specific noise frequency, and generating a second harmonic current acting on the second motor based on the first specific noise frequency and a state parameter of the second motor, wherein the first frequency range is a frequency range unique to the first motor;

[0042] Extracting a portion of the noise frequency of the second motor that is in a second frequency range as a second unique noise frequency, and generating a first harmonic current acting on the first motor based on the second unique noise frequency combined with a state parameter of the first motor, wherein the second frequency range is a frequency range unique to the second motor;

[0043] A portion of the noise frequency of the first motor that is within the third frequency range is extracted as a first common noise frequency, a portion of the noise frequency of the second motor that is within the third frequency range is extracted as a second common noise frequency, and based on the first common noise frequency and the second common noise frequency, the first motor and the second motor are controlled to have opposite phases on the common noise frequency, wherein the third frequency range is a frequency range common to the first motor and the second motor.

[0044] The first specific noise frequency, the second frequency range and the third frequency range may be determined by experiments or obtained by simulation calculations and are pre-stored in the storage device.

[0045] Since the frequency overlap range of the drive motor and the generator is large, the noise range can basically be fully covered, thereby improving the noise reduction effect.

[0046] In addition, in some implementations, only a solution of using the first motor to reduce the noise of the second motor may be included.

[0047] Specifically, in some embodiments, the first harmonic current and the second harmonic current can be obtained by looking up a table. Of course, in more embodiments, they can also be obtained by calculation. Specifically,

[0048] The state parameters of the first motor include the rotation speed and the number of pole pairs of the first motor, and the state parameters of the second motor include the rotation speed and the number of pole pairs of the second motor;

[0049] Based on the first characteristic noise frequency combined with the state parameter of the second motor, a second harmonic current acting on the second motor is generated, specifically: based on the first characteristic noise frequency combined with the speed and pole pair number of the second motor, the second harmonic current acting on the second motor is generated;

[0050] Based on the second characteristic noise frequency combined with the state parameters of the first motor, a first harmonic current acting on the first motor is generated. Specifically, the first harmonic current acting on the first motor is generated according to the second characteristic noise frequency combined with the rotation speed and pole pair number of the first motor.

[0051] In this embodiment, the order of the second harmonic current is specifically:

[0052]

[0053] Among them: B is the order of the second harmonic current, f A is the first characteristic noise frequency, n B is the speed of the second motor, p B is the number of pole pairs of the second motor;

[0054] The first harmonic current order is:

[0055]

[0056] Among them: A is the order of the first harmonic current, f B is the second unique noise frequency, n A is the speed of the first motor, p A is the number of pole pairs of the first motor.

[0057] After the second harmonic current flows into the winding of the second motor, an electromagnetic field is generated, and the electromagnetic field generates an electromagnetic force in the air gap between the stator and rotor of the motor. The electromagnetic force excites vibration on the stator of the motor and radiates noise. It should be ensured that the noise generated by the second harmonic current and the noise of the first motor's unique frequency part have opposite phases and equal amplitudes. The phase and amplitude of the first harmonic current are similar.

[0058] The number of times harmonic currents are generated based on their own speed and pole pair number can reduce the requirements on the computing power of the control system. There is no need to test and determine the comparison relationship table for various scenarios. There is no need to re-test and obtain the comparison relationship table when the motor structure is modified, which greatly reduces costs.

[0059] In addition, the specific process of determining whether the first motor and the second motor paired with the first motor are both in the running state specifically includes:

[0060] Collecting the speed and torque of the first motor and the speed and torque of the second motor;

[0061] Determine whether the speed and torque of the first motor are both non-zero, and if so, determine that the first motor is in a running state;

[0062] It is determined whether the rotation speed and torque of the second motor are both non-zero. If yes, it is determined that the second motor is in a running state.

[0063] Example 2

[0064] For a dual-drive motor system in the form of main and auxiliary drive, including a main drive motor and an auxiliary drive motor, the main drive motor is defined as a first motor, and the auxiliary drive motor is defined as a second motor paired with the first motor. The noise reduction method designed for the automotive multi-motor system is the same as that in Example 1, so it will not be repeated.

[0065] Example 3

[0066] For a motor system with a wheel rim and a wheel hub with two independently driven wheels, it includes two wheel rim drive motors or two wheel hub drive motors. At this time, when two wheel rim drive motors are used, one of the wheel rim drive motors is used as the first motor, and the other wheel rim drive motor is used as the second motor paired with the first motor; when two wheel hub drive motors are used, one of the wheel hub drive motors is used as the first motor, and the other wheel hub drive motor is used as the second motor paired with the first motor; the noise reduction method designed for the automotive multi-motor system is the same as that in Example 1, so it will not be repeated.

[0067] In particular, in this embodiment, the two drive motors are symmetrically arranged relative to the vehicle axis. The vehicle axis is specifically a line that is parallel to the driving direction and is equidistant from the wheels on both sides of the vehicle when the vehicle is traveling in a straight line. The two drive motors are axially symmetrically arranged relative to the vehicle axis, which is specifically manifested as: the projections of the two drive motors on the horizontal plane are symmetrically arranged relative to the projection of the vehicle axis on the horizontal plane.

[0068] Example 4

[0069] For a four-drive motor system or a situation with more drive motors, at this time, generally, the number of drive motors is an even number, and they will be symmetrically arranged on both sides of the vehicle. For example, for a four-drive motor system, it includes a left front drive motor, a right front drive motor, a left rear drive motor and a right rear drive motor, wherein the left front drive motor and the right front drive motor are symmetrically arranged on both sides of the vehicle, and the left rear drive motor and the right rear drive motor are symmetrically arranged on both sides of the vehicle. Therefore, the left front drive motor is defined as the first first motor, the right front drive motor is defined as the second second motor, and the first first motor is paired with the second second motor, and of course, vice versa. In addition, the left rear drive motor is defined as the second first motor, and the right rear drive motor is defined as the second second motor, and the second first motor is paired with the second second motor. Similarly, for a six-drive motor system, it is similar, and three pairs of paired first motors and second motors can be obtained.

[0070] On this basis, the noise reduction method designed for automotive multi-motor systems includes:

[0071] When the first motor and the second motor paired with the first motor are both in a running state, obtaining the noise frequency and state parameters of the first motor, and the noise frequency and state parameters of the corresponding second motor, wherein the corresponding second motor is the second motor paired with the first motor;

[0072] Extracting a portion of the noise frequency of the first motor that is in a first frequency range as a first specific noise frequency, and generating a second harmonic current acting on the corresponding second motor based on the first specific noise frequency combined with a state parameter of the corresponding second motor, wherein the first frequency range is a frequency range unique to the first motor;

[0073] Extracting a portion of the noise frequency corresponding to the second motor that is in a second frequency range as a second unique noise frequency, and generating a first harmonic current acting on the first motor based on the second unique noise frequency combined with a state parameter of the first motor, wherein the second frequency range is a frequency range unique to the second motor;

[0074] A portion of the noise frequency of the first motor that is within the third frequency range is extracted as a first common noise frequency, a portion of the noise frequency of the corresponding second motor that is within the third frequency range is extracted as a second common noise frequency, and based on the first common noise frequency and the second common noise frequency, the first motor and the corresponding second motor are controlled to have opposite phases on the common noise frequency, wherein the third frequency range is a frequency range common to the first motor and the corresponding second motor.

[0075] In addition, specifically, the first harmonic current and the second harmonic current may be obtained in a manner similar to that of Embodiment 1, but it should be noted that each pair of the first motor and the second motor should be controlled independently.

[0076] Example 5

[0077] This embodiment can be based on any one of Embodiments 1 to 4. In certain scenarios where higher noise reduction requirements are required, further noise reduction can be achieved by means of acoustic corrugated plates. Specifically, the first motor and the second motor paired therewith are both provided with acoustic corrugated plates, and the phases of the acoustic corrugated plates thereon are opposite.

[0078] If the above functions are implemented in the form of software functional units 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 invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for 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 method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

Claims

1. A noise reduction method for a multi-motor system of an automobile, characterized in that: include: When the first motor and the second motor paired with the first motor are both in a running state, obtaining the noise frequency of the first motor and the state parameter of the corresponding second motor, wherein the corresponding second motor is the second motor paired with the first motor; A portion of the noise frequency of the first motor that is within a first frequency range is extracted as a first characteristic noise frequency, and a second harmonic current acting on the corresponding second motor is generated based on the first characteristic noise frequency and a state parameter of the corresponding second motor, wherein the first frequency range is a frequency range unique to the first motor.

2. A noise reduction method for a multi-motor system of an automobile according to claim 1, characterized in that: The noise reduction method further comprises: When the first motor and the second motor paired with the first motor are both in a running state, obtaining a state parameter of the first motor and a noise frequency corresponding to the second motor; A portion of the noise frequency corresponding to the second motor that is within a second frequency range is extracted as a second characteristic noise frequency, and a first harmonic current acting on the first motor is generated based on the second characteristic noise frequency combined with a state parameter of the first motor, wherein the second frequency range is a frequency range unique to the second motor.

3. A noise reduction method for a multi-motor system of an automobile according to claim 2, characterized in that: The noise reduction method further comprises: A portion of the noise frequency of the first motor that is within the third frequency range is extracted as a first common noise frequency, a portion of the noise frequency of the corresponding second motor that is within the third frequency range is extracted as a second common noise frequency, and based on the first common noise frequency and the second common noise frequency, the first motor and the corresponding second motor are controlled to have opposite phases on the common noise frequency, wherein the third frequency range is a frequency range common to the first motor and the corresponding second motor.

4. The noise reduction method for a multi-motor system of an automobile according to claim 1, characterized in that: The state parameters of the second motor include the rotation speed and the number of pole pairs of the second motor; The second harmonic current acting on the corresponding second motor is generated based on the first characteristic noise frequency combined with the state parameters of the corresponding second motor, specifically: the second harmonic current acting on the corresponding second motor is generated according to the first characteristic noise frequency combined with the rotational speed and pole pair number of the corresponding second motor.

5. A noise reduction method for a multi-motor system of an automobile according to claim 4, characterized in that: The order of the second harmonic current is specifically: Among them: B is the order of the second harmonic current, f A is the first characteristic noise frequency, n B is the speed of the second motor, p B is the number of pole pairs of the second motor.

6. A noise reduction method for a multi-motor system of an automobile according to claim 2, characterized in that: The state parameters of the first motor include the rotation speed and the number of pole pairs of the first motor; The method of generating the first harmonic current acting on the first motor based on the second characteristic noise frequency combined with the state parameters of the first motor is specifically: generating the first harmonic current acting on the first motor based on the second characteristic noise frequency combined with the rotation speed and pole pair number of the first motor.

7. A noise reduction method for a multi-motor system of an automobile according to claim 6, characterized in that: The first harmonic current order is specifically: Among them: A is the order of the first harmonic current, f B is the second unique noise frequency, n A is the speed of the first motor, p A is the number of pole pairs of the first motor.

8. The noise reduction method for a multi-motor system of an automobile according to claim 1, characterized in that: There are one or more first motors and one or more second motors, and the number of the first motors and the second motors are equal and matched one by one.

9. A noise reduction device for a multi-motor system of an automobile, comprising a memory, a processor, and a program stored in the memory, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 8 is implemented.

10. The noise reduction device according to claim 9, characterized in that: The first motor and the second motor paired therewith are both provided with acoustic corrugated plates, and the phases of the acoustic corrugated plates thereon are opposite.

11. A hybrid vehicle, comprising a vehicle body, a drive motor and a generator, characterized in that: It also includes the noise reduction device as claimed in claim 9 or 10, wherein the driving motor is defined as a first motor, and the generator is defined as a second motor paired with the first motor.

12. A multi-drive motor vehicle, comprising a vehicle body and a plurality of drive motors, characterized in that: It also includes the noise reduction device as described in claim 9 or 10, wherein the number of the drive motors is an even number, any drive motor is defined as a first motor, and the drive motor symmetrically arranged on the other side of the vehicle is defined as a second motor paired with the first motor.

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