TWI779863B - Electronic system with heat dissipation and feedforward active noise control function - Google Patents

Abstract

An electronic system includes a fan module, an embedded controller, an error microphone, an active noise cancellation controller, and a micro speaker module. The error microphone is configured to output an error signal by detecting the noise level during the operation of the electronic system. According to the error signal and the fan information provided by the embedded controller, the active noise cancellation controller calculates the narrow-band noises associated with the actual single-blade fundamental frequency noise, the actual BPF fundamental frequency noise generated by the fan module and related phase deviations, and drives the micro speaker module accordingly for providing a noise cancellation signal. The error signal may be reduced to zero by adaptively adjusting the noise cancellation signal for canceling the noises generated during the operation of the electronic system.

Description

Electronic system with heat dissipation and feed-forward active noise control

The invention provides an electronic system with heat dissipation and feedforward active noise control functions, especially an electronic system with heat dissipation and feedforward active narrow-band noise control functions.

In the modern information society, computer systems have become an indispensable information tool for most people. In order to avoid power reduction or damage to components due to overheating, computer systems generally use fans to provide heat dissipation to dissipate the heat generated inside the device or suck in cold air from the outside of the device.

The speed and static pressure of the fan determine the air flow of the fan. The noise when the fan is running is approximately proportional to the fifth root of its speed. The faster the speed, the stronger the heat dissipation capability, but the greater the noise. As the CPU becomes more powerful, the waste heat generated inside the device also increases, and the trend of miniaturization will reduce the heat flow efficiency. How to balance heat dissipation and noise reduction is an important issue.

The invention provides an electronic device with heat dissipation and feed-forward active noise control functions The system includes a fan module, an embedded controller, an error microphone, an active noise reduction controller, and a speaker module. The fan module operates according to a fan control signal to provide heat dissipation. The embedded controller is used to provide the fan control signal and a synchronous signal, wherein the synchronous signal includes the structure and operation setting information of the fan module. The error microphone is used to detect the noise generated during the operation of the electronic system to provide a corresponding error signal. The active noise reduction controller is used to obtain an actual single-blade fundamental frequency, an actual blade passing frequency fundamental frequency, an actual blade passing frequency multiplier, and a phase offset when the fan module operates at each rotational speed; Provide a phase compensation signal according to the synchronization signal, wherein the phase compensation signal includes the actual single-blade fundamental frequency, the actual blade passing frequency fundamental frequency, and the actual blade passing frequency multiplier when the fan module operates at a current speed , and the phase offset; and generating a loudspeaker control signal according to the error signal and the phase compensation signal. The speaker module is used to generate an anti-phase noise signal according to the speaker control signal, wherein the anti-phase noise signal at least includes a first noise cancellation waveform and a second noise cancellation waveform, the first noise cancellation waveform is related to the An inverse signal of the actual single-blade fundamental frequency, and the second noise cancellation waveform is an inverse signal of the actual blade pass frequency fundamental frequency.

10: Processor

20: Fan module

30: Embedded controller

40:Speaker module

50: error microphone

60: Active noise reduction controller

62: Frequency calculator

64: Signal generator

66: Digital filter

68: Speaker drive circuit

70:Secondary Path Compensation Transfer Function Module

72: Secondary path transfer function module

74:Noise Weighting and Transformation Module

76: Adaptive filter

100: Electronic system

310-340, 410-450: steps

S _FG : Fan control signal

S _MIC : speaker control signal

S _SYN : Synchronization signal

x(n): phase compensation signal

x’(n): correction phase compensation signal

y(n): anti-phase noise signal

y'(n): Correction of anti-phase noise signal

e(n): error signal

e’(n): Error signal after processing

d(n): noise signal

FIG. 1 is a functional block diagram of an electronic system with heat dissipation and feed-forward active noise control functions in an embodiment of the present invention.

Fig. 2 is a schematic diagram of the implementation of the active noise reduction controller in the embodiment of the present invention.

Fig. 3 is a flow chart of the operation of the electronic system in the embodiment of the present invention.

No. 4 is a flowchart of the operation of the electronic system in the embodiment of the present invention.

FIG. 1 is a functional block diagram of an electronic system 100 with heat dissipation and feed-forward active noise control functions according to an embodiment of the present invention. The electronic system 100 includes a processor 10, a fan module 20, an embedded controller (embedded controller, EC) 30, a speaker module 40, an error microphone 50, and an active noise cancellation (active noise cancellation, ANC) ) controller 60.

The processor 10 can be a central processing unit (Central Processing Unit, CPU) or a graphics processing unit (Graphics Processing Unit, GPU), which is a key computing engine in the electronic system 100, responsible for executing the instructions and programs required by the operating system , is also the main source of waste heat in the electronic system 100 .

The fan module 20 can have different structures depending on its type, mainly using a motor to drive the fan blades to rotate, so as to bring cooler air to the inside of the chassis and discharge hotter air inside to achieve heat dissipation. In the present invention, the fan module 20 will operate according to a fan control signal S _FG provided by the embedded controller 30. The larger the value of the fan control signal S _FG , the faster the motor speed in the fan module 20 and the better the heat dissipation effect. The stronger it is, the louder the noise will be. During operation of the electronic system 100 , the fan module 20 is usually the main source of noise. In one embodiment, the fan control signal S _FG can be a pulse width modulation (Pulse Width Modulation, PWM) square wave signal to adjust the motor in the fan module 20 by changing its duty cycle. Rotating speed. In one embodiment, the fan module 20 may include one or more axial fans or centrifugal fans. However, the number of fans, fan types and fan driving methods included in the fan module 20 do not limit the scope of the present invention.

The embedded controller 30 stores the EC codes of various operations of the related electronic system 100 and the timing of important signals when starting up. In the shutdown state, the embedded controller 30 will keep running to wait for the user's power-on message; in the power-on state, the embedded controller 30 will control the system's standby/hibernation state, keyboard controller, charging indicator light, and fan Motor speed in module 20. The embedded controller 30 usually includes a temperature sensor (not shown in FIG. 1 ) to monitor the operating temperature of the processor 10 and output a fan control signal S _FG accordingly. When the operating temperature of the processor 10 is higher, the duty cycle of the fan control signal S _FG is larger, and the motor speed in the fan module 20 is faster; when the operating temperature of the processor 10 is lower, the duty cycle of the fan control signal S _FG is greater. The shorter the period, the slower the rotation speed of the motor in the fan module 20 .

The speaker module 40 is an electronic component capable of converting electronic signals into audio signals, and generally includes a diaphragm and a driving circuit composed of an electromagnet and a voice coil. The speaker module 40 can operate according to a speaker control signal S _MIC provided by the ANC controller 60. When the current of the speaker control signal S _MIC passes through the voice coil, the voice coil vibrates with the frequency of the current, and the vibrator connected to the voice coil The membrane vibrates, of course, which in turn pushes the surrounding air to vibrate to produce sound. In the embodiment of the present invention, the diaphragm of the speaker module 40 is disposed in the air outlet structure of the fan module 20 and can generate an anti-phase noise signal y(n) according to the speaker control signal S _MIC .

The error microphone 50 is used to pick up noise when the electronic system 100 is running, and output a corresponding error signal e(n) to the ANC controller 60 , where d(n) represents the noise signal to be eliminated during the running of the electronic system 100 . Since the fan module 20 is the main noise source, the error microphone 50 can be disposed close to the air outlet of the fan module 20 . Error microphone 50 can see through A main path and a secondary path to detect noise: the main path is related to the signal transmission path between the fan module 20 and the error microphone 50, and the noise signal d(n) will be picked up through the main path; and the secondary path is related to In the signal transmission path between the speaker module 40 and the error microphone 50 , a corrected anti-phase noise signal y′(n), one of the related anti-phase noise signals y(n), is captured through the secondary path. In more detail, the error signal e(n) output by the error microphone 50 is the difference between the noise signal d(n) and the corrected anti-phase noise signal y'(n), the value of the error signal e(n) The smaller the value, the better the noise reduction effect. In one embodiment, the error microphone 50 can be a digital MEMS (Micro Electro Mechanical System, MEMS) microphone, which has performances such as high heat resistance, high vibration resistance, and high radio frequency interference resistance. However, the type of the error microphone 50 does not limit the scope of the present invention.

The ANC controller 60 can receive a synchronous signal S _SYN from the embedded controller 30 and an error signal e(n) from the error microphone 50, wherein the synchronous signal S _SYN includes the structure of the related fan module 20 (such as the number of blades of each fan ) and operating settings (such as motor speed in different modes) information. According to the synchronous signal S _SYN and the error signal e(n), the ANC controller 60 can calculate the narrow-band noise in the noise generated by the fan module 20 during actual operation, and then provide the speaker control signal S _MIC to drive the speaker module. group 40, so that the anti-phase noise signal y(n) provided by the speaker module 40 can effectively offset the noise signal d(n), that is, the error signal e(n) can be reduced to zero as much as possible.

FIG. 2 is a schematic diagram of the implementation of the ANC controller 60 in the embodiment of the present invention. ANC controller 60 includes a frequency calculator 62, a signal generator 64, a digital filter 66, a speaker drive circuit 68, a secondary path compensation transfer function module 70, a secondary path transfer function module 72, a noise weighting and transformation module 74, and an adaptive filtering device 76.

In the present invention, the electronic system 100 can operate in an off-line mode, which can obtain information about the frequency-phase offset at a specific motor speed, and an on-line mode, which can provide feed-forward active noise control.

FIG. 3 shows a flowchart of the electronic system 100 operating in offline mode, which includes the following steps:

Step 310: The fan module 20 operates at a specific fan speed.

Step 320 : Measure the noise frequency and the corresponding power of the specific fan speed.

Step 330: Obtain the phase shift relationship of each noise frequency at a specific fan speed.

Step 340 : Design the phase compensation signal x(n) for a specific fan speed.

The noise source of the fan module 20 during operation comes from the air flow caused by the rotation of the motor, and the narrow-frequency component may originate from the thickness noise of the volume displacement generated by the movement of the fan blade, or the variable load force on the surface of the fan blade (with The blade passing frequency (BPF) noise caused by axial lift force and fan surface pull force). Since the BPF and related harmonics are related to the pressure disturbances generated as each fan blade passes a fixed reference point, a specific narrow frequency noise is generated when the blade tip generates periodic pressure waves. The frequency calculator 62 of the ANC controller 60 can obtain the current rotational speed of the fan module 20, the estimated single-blade frequency point and the number of blades according to the synchronization signal S _SYN provided by the embedded controller 30, wherein the value of BPF is the fan module 20 is the product of the motor speed and the number of blades. Assuming that the number of blades of the fan module 20 is 37, Table 1 below shows the data calculated by the frequency calculator 62, but does not limit the scope of the present invention. The unit of motor speed is rpm and the unit of frequency is hertz.

As mentioned above, the fan module 20 may have different speed settings, and the noise signals generated by different speeds may have a phase shift due to the tolerance of the electronic system 100. Therefore, the present invention first calculates the correlation in the offline mode. Phase offset information of each rotation speed of the fan module 20 .

After the fan module 20 operates at a specific speed in step 310 , then in step 320 the actual noise frequency and the corresponding power of the specific speed are measured. In one embodiment, step 320 may include operations such as audio signal cutting, audio signal zero padding, audio signal conversion, and audio signal peak determination. In more detail, when the electronic system 100 is operating in the offline mode, the error microphone 50 will capture the noise signal generated by the fan module 20 at a specific fan speed, and cut the captured noise signal into multiple segments (for example, Each section contains 1024 sampling points), extend the length of each sequence (for example, extend the length of each section to 1024×8 sampling points), place the 1024 sampling points of the original noise signal at the front end of each sequence after extension, Then, the newly added 1024×7 sampling points at the back end of each sequence are zero-padded. Then, the present invention brings Fast Fourier Transform (FFT) into each sequence after zero padding, so as to convert the noise signal from the time domain to the power frequency response in the frequency domain. Finally, the present invention determines the peaks in the frequency response to find the actual BPF fundamental frequency and the actual BPF multiplier at this particular fan speed. There may be a difference of ±100 Hz between the actual BPF fundamental frequency and the actual BPF multiplier and the theoretical values shown in Table 1.

In step 330, the present invention obtains the phase shift relationship of each noise frequency at a specific fan speed. In one embodiment, since the signal processing of the BPF base frequency will affect the BPF frequency multiplier signal, the speaker drive circuit 68 can control the speaker module 40 to play the BPF base frequency signal and the double frequency of the noise signal at a specific fan speed in sequence. Signals, ..., N multiplied signals (N is an integer greater than 1), until the multiplied signals of the specific fan speed are processed.

，因此第k個序列的訊 號可表達為sin(w * t+△φ^k)，其中K為大於1之整數，而k為介於1和K之間的整數。也就是說，當BPF基頻訊號之相位固定時，其正弦波中每一個序列的相位差異固定(例如40°,60°,80°…)，而上述動態相位正弦波中每一個序列的相位差異會增加△φ^k度的變化(例如在K=12時依序為40°,90°,140°…)。 Next, the detailed implementation of step 330 is described. The power of the audio signal is related to the frequency. First, a dynamic phase sine wave including K sequence lengths is provided for the BPF baseband signal. The phase offset of each sequence Δφ ^k is

, so the signal of the kth sequence can be expressed as sin(w * t+△φ ^k ), where K is an integer greater than 1, and k is an integer between 1 and K. That is to say, when the phase of the BPF fundamental frequency signal is fixed, the phase difference of each sequence in its sine wave is fixed (for example, 40°, 60°, 80°...), and the phase of each sequence in the above dynamic phase sine wave The difference will increase the variation of △φ ^k degrees (eg 40°, 90°, 140°... at K=12 in sequence).

Next, the speaker drive circuit 68 will control the speaker module 40 to play the dynamic phase sine waves at a specific fan speed in sequence, and the power of each sequence is calculated after being picked up by the error microphone 50, and then the power corresponding to the sequence with the smallest power is calculated. Phase is set to the phase offset of the noise frequency. For example, for the dynamic phase sine wave of the related BPF fundamental signal, if the power of the second sequence sin(w * t+Δφ ² ) is the smallest, the phase offset of the BPF fundamental signal will be set to Δφ ² . For the dynamic phase sine wave of the related BPF double frequency signal, if the kth sequence sin(w * t+Δφ ^k ) has the smallest power, the phase offset of the BPF double frequency signal will be set to Δφ ^k .

Finally, in step 340, the present invention will repeat steps 310-330 for each fan speed of the fan module 20, so as to design a corresponding phase compensation signal x(n) for each fan speed, wherein the fundamental frequency of the BPF and multipliers each have different power and phase.

FIG. 4 shows a flowchart of the electronic system 100 operating in the live mode, which includes the following steps:

Step 410: The error microphone 50 captures the noise and provides a corresponding error signal e(n).

Step 420: The ANC controller 60 obtains the number of blades of each fan in the fan module 20 and the motor speed in each mode from the synchronization signal S _SYN provided by the embedded controller 30, and provides a corresponding phase compensation signal x(n).

Step 430: The ANC controller 60 obtains information such as the actual single-blade fundamental frequency, actual frequency multiplier, and actual BPF when the fan module 20 is in operation according to the error signal e(n) and the phase compensation signal x(n), and provides information accordingly Speaker control signal S _MIC .

Step 440: The speaker module 40 generates an anti-phase noise signal y(n) according to the speaker control signal S _MIC .

Step 450: The ANC controller 60 provides the corrected reference signal x'(n) for the secondary path corrected reference signal x(n), and corrects the reverse noise signal y(n) to provide the corrected reverse noise signal y'( n); Execute step 310.

In step 410, when the electronic system 100 is operating in the on-line mode, the error microphone 50 picks up the noise and provides a corresponding error signal e(n). As mentioned above, the error signal e(n) provided by the error microphone 50 is the difference between the noise signal d(n) and the corrected anti-phase noise signal y'(n), and the noise signal d(n) mainly It comes from the rotation of the fan blades when the fan module 20 is in operation.

In step 420, the signal generator 64 of the ANC controller 60 will provide the corresponding phase compensation signal x(n) according to the data calculated by the frequency calculator 62 and the data obtained in the offline mode, wherein the phase compensation signal x (n) Including information such as the actual frequency multiplier, actual BPF, phase offset, and sound pressure spectrum (dBSPL) of the fan module 20 at the current speed, the reference power value of the speaker control signal S _MIC can be determined, and by adjusting the digital The parameter W(Z) of the filter 66 can change the power level of the speaker control signal S _MIC .

In steps 430 and 440, the digital filter 66 of the ANC controller 60 will drive the speaker driving circuit 68 according to the error signal e(n) and the phase compensation signal x(n) to output the speaker control signal S _MIC , and then drive the speaker module Group 40 provides an inverted noise signal y(n), where W(Z) represents an adjustable operating parameter of digital filter 66 .

，再依據預估訊號

來校正參考訊號x(n)以提供校正後參考訊號x’(n)。ANC控制器60之次級路徑轉移函數模組72可為一頻譜分析儀，用來量測次級路徑的實際頻率響應S(Z)，再依此校正反向噪音訊號y(n)以提供校正後反向噪音訊號y’(n)，進而補償次級路徑對訊號傳輸造成的影響。 The characteristics of the speaker module 40 itself and the white noise (white noise) sent to the fan module 20 during operation will affect the secondary path between the speaker module 40 and the error microphone 50, assuming the anti-phase noise currently provided by the speaker module 40 The signal y(n) can completely cancel the noise signal d(n), but after being transmitted through the secondary path, the anti-phase noise signal y(n) captured by the error microphone 50 may not be able to completely cancel due to signal attenuation or distortion. Cancels the noise signal d(n). Therefore, in step 450, the secondary path compensation transfer function module 70 of the ANC controller 60 can obtain the estimated signal of the secondary path from the embedded controller 30

, and then according to the estimated signal

to correct the reference signal x(n) to provide a corrected reference signal x'(n). The secondary path transfer function module 72 of the ANC controller 60 can be a spectrum analyzer, which is used to measure the actual frequency response S(Z) of the secondary path, and then correct the reverse noise signal y(n) accordingly to provide After correction, the reverse noise signal y'(n) is used to compensate the influence of the secondary path on the signal transmission.

The noise weighting conversion module 74 is coupled to the error microphone 50, and can process the error signal e(n) measured by the error microphone 50 according to a specific signal weighting method and signal conversion method, and then convert the processed error signal e'( n) to the adaptive filter 76 . In one embodiment, the noise weighting conversion module 74 can use A weighting (A weighting) and fast Fourier transform (Fast Fourier Transform, FFT) to process the error signal e(n). However, the signal weighting method and signal conversion method used by the noise weighting conversion module 74 do not limit the scope of the present invention.

The adaptive filter 76 is coupled to the secondary path compensation transfer function module 70 and the noise weight conversion module 74, and can process the corrected phase compensation signal x'(n) and the processed error signal e' according to a specific algorithm (n), and then adjust the parameter W(Z) of the digital filter 66. More specifically, the corrected phase compensation signal x'(n) includes information such as the actual motor speed of the fan module 20, the actual fundamental frequency of a single blade, the actual frequency multiplication, the actual BPF, and the phase offset, and the adaptive filter 76 then According to the processed error signal e'(n), the corrected actual single-blade fundamental frequency, corrected actual frequency multiplier, and corrected actual BPF and other related narrow-band noise information can be obtained when the fan module 20 is in operation, and then according to The parameter W(Z) of the digital filter 66 is adjusted. In this way, when the digital filter 66 drives the speaker driving circuit 68 to output the speaker control signal S _MIC , the anti-phase noise signal y(n) generated by the speaker module 40 will reflect the actual operation status of the fan module 20 and the current Noise reduction level. More specifically, the antiphase noise signal y(n) includes at least a first noise cancellation waveform and a second noise cancellation waveform, wherein the first noise cancellation waveform is an inverse signal relative to the actual single-blade fundamental frequency, and the second noise cancellation waveform The second noise cancellation waveform is the inverse signal relative to the actual BPF fundamental frequency.

In one embodiment, the adaptive filter 76 can process the corrected phase compensation signal x'(n) and the processed error signal e'(n) according to a Least mean square (LMS) algorithm. However, the algorithm used by the adaptive filter 76 does not limit the scope of the present invention.

To sum up, the electronic system 100 of the present invention first obtains the phase offset information of each rotation speed of the relevant fan module 20 in an offline mode. Then when operating in the online mode, the error microphone 50 will pick up the noise and output a corresponding error signal, and the ANC controller 60 will calculate the fan module 20 according to the error signal and the fan information provided by the embedded controller 30. The narrow-band noise (actual single-blade fundamental frequency noise or actual BPF fundamental frequency noise) in the noise generated during actual operation, and then drive the speaker module 40 accordingly to provide the anti-phase noise signal y(n), so that the anti-phase noise signal y(n) can offset the noise generated when the electronic system 100 is in operation. By adaptively adjusting the reverse noise signal to adjust the value of the error signal to 0, the invention can take into account the important issues of heat dissipation and noise reduction, and can offset the phase shift caused by system tolerances to improve the accuracy of active noise control .

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

40:Speaker module

50: error microphone

60: Active noise reduction controller

62: Frequency calculator

64: Signal generator

66: Digital filter

68: Speaker drive circuit

70:Secondary Path Compensation Transfer Function Module

72: Secondary path transfer function module

74:Noise Weighting and Transformation Module

76: Adaptive filter

S _MIC : speaker control signal

S _SYN : Synchronization signal

x(n): phase compensation signal

x’(n): Corrected position compensation signal

y(n): anti-phase noise signal

y'(n): Correction of anti-phase noise signal

e(n): error signal

e’(n): Error signal after processing

d(n): noise signal

Claims (11)

An electronic system with heat dissipation and feed-forward active noise control functions, which includes: a fan module, used to operate according to a fan control signal to provide heat dissipation; an embedded controller (embedded controller, EC), used To provide the fan control signal and a synchronous signal, wherein the synchronous signal contains information about the structure and operation settings of the fan module; an error microphone is used to detect the noise generated when the electronic system is operating to provide a corresponding An error signal; an active noise cancellation (ANC) controller, used to: obtain an actual single-blade fundamental frequency and an actual blade passing frequency (blade passing) when the fan module operates at each speed frequency, BPF) base frequency, an actual BPF multiplier, and a phase offset; a phase compensation signal is provided according to the synchronous signal, wherein the phase compensation signal includes the actual unit when the fan module operates at a current speed blade fundamental frequency, the actual BPF fundamental frequency, the actual BPF multiplier, and the phase offset; and generating a speaker control signal according to the error signal and the phase compensation signal; and a speaker module for generating a speaker control signal according to the speaker control signal to generate an anti-phase noise signal, wherein the anti-phase noise signal includes at least a first noise cancellation waveform and a second noise cancellation waveform, the first noise cancellation waveform is an inverse signal related to the actual single-blade fundamental frequency , and the second noise cancellation waveform is an inverse signal relative to the actual BPF fundamental frequency. The electronic system as described in claim 1, wherein the active noise reduction controller includes: a frequency calculator, which is used to obtain an estimated single-blade fundamental frequency when the fan module operates at each speed according to the synchronization signal , an estimated single-blade frequency multiplier and an estimated BPF fundamental frequency; a signal generator for performing an audio signal cutting operation, an audio signal zero filling operation, and an audio signal on the signal detected by the error microphone conversion operation and a sound signal peak judgment operation to obtain the actual single-blade fundamental frequency, the actual BPF fundamental frequency, and the actual BPF multiplier frequency when the fan module operates at each rotational speed; and a digital filter for and performing an operation on the phase compensation signal to determine a reference power value of the loudspeaker control signal. The electronic system as described in claim 2, wherein: the error microphone is also used to detect a noise signal generated when the fan module operates at a specific speed; the speaker module also broadcasts a BPF base of the noise signal Frequency signal, the BPF base frequency signal is a first dynamic phase sine wave including a plurality of sequence lengths; the active noise reduction controller is also used to set the phase corresponding to the sequence with the smallest power in the first dynamic phase sine wave is the phase offset of the BPF fundamental frequency signal in the noise signal; after playing the BPF fundamental frequency signal of the noise signal, the speaker module also plays at least one N-fold frequency signal of the noise signal, and the at least one N-fold Frequency signals are complex numbers A second dynamic phase sine wave with a sequence length; the active noise reduction controller is also used to set the phase corresponding to the sequence with the smallest power in the second dynamic phase sine wave as the at least one N multiple frequency in the noise signal a phase offset of the signal; and N is an integer greater than 1. The electronic system as described in claim 2, wherein the active noise reduction controller further includes: an adaptive filter, which is used to adjust the phase used by the digital filter when performing calculations according to the phase compensation signal and the error signal parameter, and then adaptively adjust the power value of the speaker control signal. The electronic system as claimed in claim 4, wherein: the adaptive filter uses a least mean square (LMS) algorithm to process the phase compensation signal and the error signal. The electronic system as described in claim 4, wherein the active noise reduction controller further includes: a secondary path compensation transfer function module, coupled to the embedded controller to receive an estimated signal of the secondary path, and then according to the The estimated signal of the secondary path is used to correct the phase compensation signal to provide a corrected phase compensation signal; and a noise weighting and conversion module is used to process the error signal according to a specific signal weighting method and a specific signal conversion method to provide a processed error signal, wherein: The secondary path is related to the signal transmission path between the speaker module and the error microphone; and the adaptive filter is based on the corrected phase compensation signal and the processed error signal to adjust the digital filter when performing operations parameters used. The electronic system as described in claim 6, wherein the active noise reduction controller further includes: a secondary path transfer function module, which is used to measure the actual frequency response of the secondary path, and then correct the reverse noise signal accordingly To provide a corrected reverse noise signal. The electronic system as described in claim 6, wherein the active noise reduction controller is further used to adjust the parameters used by the digital filter when performing calculations according to the corrected phase compensation signal and the processed error signal, so as to adapt to The power value of the speaker control signal is adjusted selectively to reduce the value of the error signal. The electronic system as claimed in claim 1, wherein the error microphone is arranged at the air outlet of the fan module. The electronic system as claimed in claim 1, wherein the ANC controller is further used to: measure an actual frequency response of a signal transmission path between the speaker module and the error microphone; and Correcting the reverse noise signal according to the actual frequency response to provide a corrected reverse noise signal. The electronic system as claimed in claim 1, wherein the ANC controller is further configured to: receive an estimated frequency response of a signal transmission path between the speaker module and the error microphone from the embedded controller; and based on The estimated frequency response corrects the phase compensation signal to provide a corrected phase compensation signal.

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