A self-adaptive music sounding control method for a washing machine motor

Abstract

The application discloses a self-adaptive music sounding control method for a washing machine motor, which comprises the following steps: S1, system initialization; S2, real-time working condition monitoring; S3, audio instruction generation; S4, audio waveform generation: a discrete sinusoidal wave sampling sequence is generated by an MCU according to a single-tone parameter and is used as an audio disturbance current Iq_audio(t); S5, current loop superposition control: the audio disturbance current Iq_audio(t) is superposed to a basic torque current Iq_base at a current loop given end of FOC vector control, so that a total torque current given Iq_ref is obtained, and an excitation current given Id_ref is kept as 0; and S6, motor vibration sounding: a small-amplitude alternating electromagnetic excitation is superposed to a basic driving magnetic field of a motor stator winding, so that controllable micro-vibration is generated between the stator and a machine shell, a prompt sound or music is formed through a washing machine cavity structure and air conduction. According to the application, a buzzer, a loudspeaker and all driving circuits are directly cancelled, patching, panel opening, wire harness assembly, function testing and hidden costs such as bad repair are saved.

Description

Technical Field

[0001] This invention relates to the field of washing machine prompt sound technology, specifically a method for adaptive music sound control of a washing machine motor. Background Technology

[0002] The current home appliance market is becoming increasingly competitive, and order prices are being driven lower and lower. Modern household washing machines generally have external sound-producing devices such as passive buzzers and surface-mount speakers, which require separate circuit layout, reserved PCB space, structural openings, and wiring harness assembly. Mass production material costs, labor assembly costs, and after-sales failure rates are all relatively high.

[0003] Washing machines require additional sound-generating components such as passive buzzers, surface-mount speakers, and piezoelectric buzzers, along with dedicated drive circuits, PCB layouts, panel openings, wiring harnesses, and mounting structures. This directly increases BOM material costs and introduces hidden costs throughout the entire process, including surface mounting, assembly, testing, and rework. In the context of intensified price competition in the industry, this significantly weakens the product's cost-effectiveness and profit margin. The sound-generating components and drive circuits are independent add-on modules. In the humid, vibrating, and long-term powered washing machine operating environment, they are prone to component failure, poor wiring connections, water ingress through openings, and resonance noise, increasing the overall defect rate and after-sales maintenance costs, and affecting product stability and brand reputation. Therefore, we propose an adaptive music sound control method for washing machine motors. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive music sound control method for washing machine motors to solve the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for adaptive music sound control of a washing machine motor, comprising the following steps: S1. System initialization: Load FOC vector driver, preset audio library, operating parameters, and complete motor position calibration, drive circuit and button circuit self-test; S2. Real-time operating condition monitoring: Continuously collects motor speed, phase current, load status, eccentricity, button signals and washing program status to determine the current washing, rinsing, spin-drying, shutdown and fault conditions; S3. Audio command generation: Based on button triggers, program nodes, and fault events, call the corresponding prompt tone or music from the preset audio library, and decompose the audio signal into a single tone sequence. Each single tone is configured with a fixed frequency, amplitude, and duration. S4. Audio waveform generation: The MCU generates a discrete sine wave sampling sequence according to the single tone parameters, which is used as the audio disturbance current Iq_audio(t); S5. Current Loop Superposition Control: At the current loop reference terminal of FOC vector control, the audio disturbance current Iq_audio(t) is superimposed on the base torque current Iq_base to obtain the total torque current reference Iq_ref, while keeping the excitation current reference Id_ref constant at 0. S6. Motor vibration sound generation: The stator winding of the motor is superimposed with a small amplitude alternating electromagnetic excitation on the basic driving magnetic field, which causes the stator and the casing to produce controllable micro-vibration, which is transmitted through the washing machine cavity structure and air to form a prompt sound or music.

[0006] Preferably, it also includes S7, adaptive adjustment: dynamically adjusts the amplitude, frequency and duration of sound emission according to working conditions and abnormal states, and blocks or pauses sound emission in abnormal states to ensure motor safety and normal execution of the washing program.

[0007] Preferably, the adaptive adjustment includes: immediately pausing or disabling the sound function when the motor experiences overcurrent, stall, overheating, overload, or excessive eccentricity; limiting the sound amplitude during high-speed dehydration, outputting only short, low-frequency prompts; and supporting one-click on / off of the audio function via software.

[0008] Preferably, the discrete sine wave sampling sequence satisfies: Where f is the single-tone frequency, and its value ranges from 200Hz to 1200Hz; A represents the current amplitude, which is 10% to 70% of the motor's rated current. Ts is the sampling period, which is consistent with the FOC current loop control period, and its value ranges from 50μs to 200μs. k is the sampling sequence number, which continues until the set sound duration ends.

[0009] Preferably, the total torque current is given to satisfy: Iq_ref = Iq_base + Iq_audio(t) Wherein, Iq_base is the base torque current output by the speed loop under washing, rinsing and spin-drying conditions; Iq_audio(t) is the short-time small-amplitude audio disturbance current; after superposition, the motor torque fluctuation is ≤5% and the speed deviation is ≤2%.

[0010] Preferably, the preset audio library includes power-on tone, power-off tone, program end melody, key prompt tone, child lock prompt tone, gear shift tone, and graded fault alarm tone; the fault prompt tone is a rapid high-frequency tone, and the regular prompt tone is a soft mid-low frequency tone, and resonance noise is eliminated by cavity acoustic filtering.

[0011] Preferably, the response delay of the key prompt tone is ≤7ms.

[0012] Preferably, the audio waveform is pre-generated and cached in memory, and then directly read and output when triggered.

[0013] An adaptive music sound control system for a washing machine motor, the system being used to execute the control method described above; comprising: an FOC drive module, a working condition monitoring module, an audio library management module, an audio waveform generation module, a current loop superposition module, a safety protection module, and a cavity acoustic optimization module; the current loop superposition module is used to superimpose the audio disturbance current onto Iq_base, keeping Id_ref=0, without affecting the speed loop, position loop, and SVPWM core output; the safety protection module is used to shield the sound generation during overcurrent, stall, overheating, overload, and excessive eccentricity, and to limit the amplitude during high-speed spin drying.

[0014] A washing machine employs a permanent magnet synchronous BLDC motor and FOC vector control drive to execute the control method described above. The washing machine is a fully automatic pulsator washing machine, a drum washing machine, or a washer-dryer combo.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Significantly reduced costs and high mass production value: Directly eliminating the buzzer, speaker, and all drive circuits saves 0.6-0.7 yuan in BOM cost per unit; eliminating hidden costs such as surface mount technology, panel opening, wiring harness assembly, functional testing, and defective repairs, resulting in an overall cost reduction of 1.0-1.5 yuan per unit; based on an annual production of 1 million units, the annual cost reduction can reach 1 million to 1.5 million yuan, excluding after-sales maintenance savings, significantly enhancing market competitiveness.

[0016] 2. Adaptable to all working conditions without affecting overall machine performance: The automatic working condition graded sound emission strategy greatly avoids affecting the operation of the washing machine; the motor torque fluctuation during the sound emission process is ≤5% and the speed deviation is ≤2%, without machine body vibration or eccentric weight increase problems, and does not interfere with the normal operation of the core programs of washing, rinsing and spin-drying, and can be used commercially in all weather conditions.

[0017] 3. Millisecond response time, consistent with the sound interaction experience of traditional buzzers: The response latency of button prompts is ≤7ms, which is the same as that of traditional buzzers; it supports single click, continuous click, long press and other operations, and the prompts are crisp, without delay, stuttering and crosstalk. The user's operation feel is completely consistent with the original buzzer, and there is no need to change the usage habits.

[0018] 4. Acoustic optimization for clean and comfortable sound quality: The washing machine cavity is specially filtered and tuned to eliminate resonance noise and harsh noise; it can play a variety of sound effects such as startup music, program end melody, and graded fault prompts, which can distinguish scenes and clearly distinguish layers, thereby enhancing product differentiation and user experience.

[0019] 5. Zero hardware modification and easy portability: It fully reuses existing hardware without adding new components, modifying the PCB, or changing the structure; it can be quickly ported to all FOC-driven home appliances such as inverter refrigerators, inverter fans, and inverter kitchen appliances, with strong versatility and wide expandability.

[0020] 6. Safe and reliable with high fault tolerance: The drive protection takes priority over the sound function, and the sound is automatically blocked or limited under abnormal working conditions; it supports independent switching of audio function, which takes into account both practicality and safety, reduces after-sales failure rate, and improves the stability of the whole machine. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of the present invention; Figure 2 This is a diagram of the sound-generating driver of the present invention; Figure 3 This is a flowchart of the sound generation process of the present invention; Figure 4 This is a flowchart of the FOC control sound generation process of the present invention; Figure 5 This is a waveform diagram of the measured motor current and speed of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0023] Please see Figure 1-5 In this embodiment of the invention, a method for adaptive music sound control of a washing machine motor includes the following steps: S1. System initialization: Load FOC vector driver, preset audio library, operating parameters, and complete motor position calibration, drive circuit and button circuit self-test; S2. Real-time operating condition monitoring: Continuously collects motor speed, phase current, load status, eccentricity, button signals and washing program status to determine the current washing, rinsing, spin-drying, shutdown and fault conditions; S3. Audio command generation: Based on button triggers, program nodes, and fault events, call the corresponding prompt tone or music from the preset audio library, and decompose the audio signal into a single tone sequence. Each single tone is configured with a fixed frequency, amplitude, and duration. S4. Audio waveform generation: The MCU generates a discrete sine wave sampling sequence according to the single tone parameters, which is used as the audio disturbance current Iq_audio(t); S5. Current Loop Superposition Control: At the current loop reference terminal of FOC vector control, the audio disturbance current Iq_audio(t) is superimposed on the base torque current Iq_base to obtain the total torque current reference Iq_ref, while keeping the excitation current reference Id_ref constant at 0. S6. Motor vibration sound generation: The stator winding of the motor is superimposed with a small amplitude alternating electromagnetic excitation on the basic driving magnetic field, which causes the stator and the casing to produce controllable micro-vibration, which is transmitted through the washing machine cavity structure and air to form a prompt sound or music.

[0024] S7. Adaptive Adjustment: Dynamically adjusts the amplitude, frequency, and duration of the sound output based on operating conditions and abnormal states. In abnormal states, sound output is muted or paused to ensure motor safety and normal operation of the washing program. The adaptive adjustment includes: immediately pausing or muting the sound output when the motor experiences overcurrent, stall, overheating, overload, or excessive eccentricity; limiting the sound amplitude during high-speed spin-drying, outputting only a short, low-frequency alert tone; and supporting one-click on / off of the audio function via software.

[0025] The discrete sinusoidal sampling sequence satisfies: Where f is the single-tone frequency, and its value ranges from 200Hz to 1200Hz; A represents the current amplitude, which is 10% to 70% of the motor's rated current. Ts is the sampling period, which is consistent with the FOC current loop control period, and its value ranges from 50μs to 200μs. k is the sampling sequence number, which continues until the set sound duration ends.

[0026] The total torque current given satisfies: Iq_ref = Iq_base + Iq_audio(t) Wherein, Iq_base is the base torque current output by the speed loop under washing, rinsing and spin-drying conditions; Iq_audio(t) is the short-time small-amplitude audio disturbance current; after superposition, the motor torque fluctuation is ≤5% and the speed deviation is ≤2%.

[0027] The preset audio library includes power-on tone, power-off tone, program end melody, key prompt tone, child lock prompt tone, gear shift tone, and graded fault alarm tone; the fault prompt tone is a rapid high-frequency tone, and the regular prompt tone is a soft mid-low frequency tone, and resonance noise is eliminated by cavity acoustic filtering; the response delay of the key prompt tone is ≤7ms.

[0028] The audio waveform is pre-generated and cached in memory, and is directly read and output when triggered.

[0029] An adaptive music sound control system for a washing machine motor, the system being used to execute the control method described above; comprising: an FOC drive module, a working condition monitoring module, an audio library management module, an audio waveform generation module, a current loop superposition module, a safety protection module, and a cavity acoustic optimization module; the current loop superposition module is used to superimpose the audio disturbance current onto Iq_base, keeping Id_ref=0, without affecting the speed loop, position loop, and SVPWM core output; the safety protection module is used to shield the sound generation during overcurrent, stall, overheating, overload, and excessive eccentricity, and to limit the amplitude during high-speed spin drying.

[0030] A washing machine employs a permanent magnet synchronous BLDC motor and FOC vector control drive to execute the control method described above. The washing machine is a fully automatic pulsator washing machine, a drum washing machine, or a washer-dryer combo.

[0031] 1. High-frequency harsh noise: Built-in multi-segment preset audio library to distinguish the sound effects of different scenarios such as power-on, power-off, program end, child lock, gear shift, fault alarm, etc. The fault prompt tone is urgent and eye-catching, while the regular prompt tone is soft and clear, improving the sound quality and user experience.

[0032] 2. Safety-first scheduling and protection: When the motor experiences overcurrent, stall, overheating, overload, or excessive eccentricity, the sound function will be immediately suspended or disabled, and the safety protection logic will be executed first; the sound amplitude will be limited during high-speed dehydration, and only a short, low-frequency warning sound will be retained; the audio function can be turned on or off with one click in the software, which is compatible with traditional usage habits and reduces the risk of failure.

[0033] 3. Sound is generated through vibration of the entire machine: ①Pre-define the key prompt tone, startup music, program end melody, and fault alarm tone into a single-tone sequence (each single tone corresponds to a fixed frequency, duration, and volume). ② For each single tone, the MCU generates a discrete sine wave sampling sequence in real time: ; Where: f: single-tone frequency (frequency ranges from 200 to 1200 Hz depending on different operating conditions); A: Amplitude (ranging from 10% to 70% of the rated current, depending on the operating conditions). Sampling period (consistent with the FOC current loop period, typically between 50 and 200 μs); k: Sampling sequence number, which continues until the set duration ends (the appropriate sound duration is automatically set according to different working conditions). ③ The generated sine wave sequence is stored in the buffer in advance, and can be read directly when triggered by a button or when a program node arrives, without the need for complex decoding, and output in milliseconds.

[0034] ④ The motor stator windings are superimposed with a small-amplitude alternating electromagnetic excitation on the basic dynamic magnetic field, causing the motor stator and casing to produce regular micro-vibrations; Id_ref is always 0, and the audio disturbance is only superimposed on Iq_ref, i.e., Iq_ref = Iq_base + Iq_audio(t); Iq_audio(t) is a small-amplitude, short-time AC waveform. Among them, Iq_base is the basic torque current required for the previous washing / rinsing / spinning (output by the speed loop); Iq_audio(t) is the short-time, small-amplitude sine wave generated above. The superposition is only completed at the current loop setpoint, without modifying the speed loop, position loop, or tampering with the PWM main waveform; the current loop PI regulator automatically compensates for small disturbances, so that the average torque and average speed remain completely unchanged, only generating controllable micro-vibrations. The vibration energy is conducted through the structure of the washing machine and the air to form a clear and audible prompt sound or music, achieving buzzer-free sound generation.

[0035] The working principle of this invention is as follows: Loading the FOC driver, audio waveform library, and operating parameters; calibrating the motor position; and performing self-tests on the driver and buttons. During operation, continuously collecting motor speed, current, load, eccentricity, and button signals to determine the current operating condition. A short prompt tone is invoked when a button is triggered; the corresponding music is invoked at the program node; and an alarm tone is invoked in case of a fault, with amplitude and frequency matched according to the operating condition. The audio waveform is decoupled and superimposed onto the current loop setpoint, and then regulated by PI and SVPWM to output the drive voltage. Micro-excitation is superimposed on the stator to generate vibration, which is conducted through the cavity to form sound. Torque fluctuations are suppressed in real time, amplitude is limited at high speeds, and sound is muted in case of abnormalities to ensure stability.

[0036] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adaptive music sound control of a washing machine motor, characterized in that, Includes the following steps: S1. System initialization: Load FOC vector driver, preset audio library, operating parameters, and complete motor position calibration, drive circuit and button circuit self-test; S2. Real-time operating condition monitoring: Continuously collects motor speed, phase current, load status, eccentricity, button signals and washing program status to determine the current washing, rinsing, spin-drying, shutdown and fault conditions; S3, Audio Command Generation: Based on button triggers, program nodes, and fault events, call the corresponding prompt tone or music from the preset audio library, decompose the audio signal into a single tone sequence, and configure each single tone with a fixed frequency, amplitude, and duration. S4. Audio waveform generation: The MCU generates a discrete sine wave sampling sequence according to the single tone parameters, which is used as the audio disturbance current Iq_audio(t); S5. Current Loop Superposition Control: At the current loop reference terminal of FOC vector control, the audio disturbance current Iq_audio(t) is superimposed on the base torque current Iq_base to obtain the total torque current reference Iq_ref, while keeping the excitation current reference Id_ref constant at 0. S6. Motor vibration sound generation: The stator winding of the motor is superimposed with a small amplitude alternating electromagnetic excitation on the basic driving magnetic field, which causes the stator and the casing to produce controllable micro-vibrations, which are transmitted through the washing machine cavity structure and air to form a prompt sound or music.

2. The adaptive music sound control method for a washing machine motor according to claim 1, characterized in that, It also includes S7 and adaptive adjustment: dynamically adjusts the amplitude, frequency and duration of the sound output according to the working conditions and abnormal states, and blocks or pauses the sound output in abnormal states to ensure the safety of the motor and the normal execution of the washing program.

3. The adaptive music sound control method for a washing machine motor according to claim 2, characterized in that, The adaptive adjustment includes: immediately pausing or disabling the sound function when the motor experiences overcurrent, stall, overheating, overload, or excessive eccentricity; limiting the sound amplitude during high-speed dehydration, outputting only short, low-frequency alert sounds; and supporting one-click on / off of the audio function via software.

4. The adaptive music sound control method for a washing machine motor according to claim 1, characterized in that, The discrete sinusoidal sampling sequence satisfies: Where f is the single-tone frequency, and its value ranges from 200Hz to 1200Hz; A represents the current amplitude, which is 10% to 70% of the motor's rated current. Ts is the sampling period, which is consistent with the FOC current loop control period, and its value ranges from 50μs to 200μs. k is the sampling sequence number, which continues until the set sound duration ends.

5. The adaptive music sound control method for a washing machine motor according to claim 1, characterized in that, The total torque current given satisfies: Iq_ref = Iq_base + Iq_audio(t) Wherein, Iq_base is the base torque current output by the speed loop under washing, rinsing and spin-drying conditions; Iq_audio(t) is the short-time small-amplitude audio disturbance current; after superposition, the motor torque fluctuation is ≤5% and the speed deviation is ≤2%.

6. The adaptive music sound control method for a washing machine motor according to claim 1, characterized in that, The preset audio library includes power-on tone, power-off tone, program end melody, key prompt tone, child lock prompt tone, gear shift tone, and graded fault alarm tone; the fault prompt tone is a rapid high-frequency tone, and the regular prompt tone is a soft mid-low frequency tone, and resonance noise is eliminated by cavity acoustic filtering.

7. The adaptive music sound control method for a washing machine motor according to claim 6, characterized in that, The response delay for key prompt sounds is ≤7ms.

8. The adaptive music sound control method for a washing machine motor according to claim 1, characterized in that, The audio waveform is pre-generated and cached in memory, and is directly read and output when triggered.

9. A washing machine motor adaptive music sound control system, characterized in that, The system is used to execute the control method according to any one of claims 1-8; it includes: an FOC drive module, a working condition monitoring module, an audio library management module, an audio waveform generation module, a current loop superposition module, a safety protection module, and a cavity acoustic optimization module; the current loop superposition module is used to superimpose the audio disturbance current onto Iq_base and keep Id_ref=0; the safety protection module is used to shield the sound generation when there is overcurrent, stall, overheating, overload, or excessive eccentricity, and to limit the amplitude during high-speed dehydration.

10. A washing machine, characterized in that, The washing machine is driven by a permanent magnet synchronous BLDC motor and FOC vector control, and executes the control method described in any one of claims 1-8. The washing machine is a fully automatic pulsator washing machine, a drum washing machine, or a washer-dryer combo.

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