KR100208167B1 - Active noise control device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active noise control device capable of removing noise sources by actively controlling noise generated by motors and other actuators in household appliances.

To this end, the present invention is a sensor unit for detecting a noise signal, a signal amplification unit for amplifying and outputting the noise signal output from the sensor unit, and a low pass filtering of the low-pass filtering of the noise signal amplified from the signal amplification unit A filter for detecting the phase of the noise signal low-pass filtered from the first low pass filter, a microcom unit for real-time processing of the noise signal output from the first low pass filter and the phase detecting unit without phase delay; A second low pass filter for low frequency filtering and outputting the signal output from the microcomputer unit, a power amplifying unit for power amplifying and outputting the low pass filtered signal output from the second low pass filter, and a power amplification unit for the power amplifying unit It is composed of an output unit for outputting a signal to the acoustic sound field space.

Description

Active noise control

As shown in FIG. 1, the active noise control principle generates noise by overlapping the generated noise signal N with an artificial sound S having the same amplitude and antiphase as the noise signal generated in a certain acoustic space. It is a principle to attenuate.

As a result, the noise signal is synthesized by combining the noise signal (N) and the artificial sound (S), as shown in FIG. 2, and the controlled noise signal (N + S) is theoretically zero to remove the noise. do.

FIG. 3 is a block diagram illustrating the actual implementation of the active noise control principle in a circuit.

As shown, from the sensor unit 1 for detecting the noise signal, a signal amplifier 2 for amplifying and outputting the noise signal output from the sensor unit 1, and from the signal amplifier 2 A first low pass filter 3 for low frequency filtering and outputting the amplified noise signal, a real time signal processor 4 for real time processing of the low pass filtered noise signal from the first low pass filter 3 and a phase delay, and In addition, the microcomputer 5 for real-time control of the noise signal in parallel with the real-time signal processor 4, the second low-pass filter unit 6 for low-pass filtering the signal output from the real-time signal processor 4 and A power amplifier 7 for power amplifying and outputting the low pass filtered signal from the second low pass filter 6 and outputting the power amplified signal from the power amplifier 7 to the acoustic sound field space Is composed of an output unit 8.

Referring to Figures 4 and 6 attached to the operation of the conventional active noise control device configured as described above are as follows.

First, the sensor unit 1 detects and outputs a noise signal X (k) in an acoustic sound field space.

Here, X (k) is a signal input from the microphone.

Then, the signal amplifier 2 amplifies and outputs the noise signal X (k) detected by the sensor unit 1.

Accordingly, the first low pass filter 3 performs low pass filtering on the amplified noise signal X (k).

Then, the real-time signal processing unit 4 converts the low-pass filtered noise signal X (k) from the first low pass filter unit 3 into a digital signal through an internal analog / digital converter (not shown in the accompanying drawings). The artificial sound having the same amplitude and inverse phase as that of the converted noise signal X (k) is generated and outputted through a digital / analog converter (not shown in the accompanying drawings).

That is, the real-time signal processor 4 initializes the internal RAM (not shown in the accompanying drawings) as shown in FIGS. 4 and 6, and sets the order of the filter.

The low-pass filtered noise signal X (k) from the first low pass filter unit 3 is converted into a digital signal through an internal analog / digital converter (not shown in the accompanying drawings) and the converted noise signal [ X (k)] is output through the control target system 4a such as a home appliance such as a refrigerator in the real time signal processor 4.

In addition, the digital filtering coefficient adjusting unit 4b in the real-time signal processing unit 4 carries out a low-pass filtered noise signal X (k) from the first low-pass filter unit 3 as an internal analog / digital converter. Unsigned) is converted into a digital signal, the digital filtering coefficient of the converted noise signal X (k) is adjusted, and the adjusted digital filtering coefficient signal y (k) is output.

Here, y (l) is an output signal generated from the output unit.

Then, the mixer 4c in the real time signal processor 4 mixes the artificial sound output from the artificial sound generator 4a and the digital filtering coefficient signal y (k) adjusted from the digital filtering coefficient adjuster 4b. To output the residual noise signal [E (k)].

Thereafter, the digital filtering coefficient adjusting unit 4b in the real time signal processing unit 4 feeds back the error of the residual noise signal E (k) output from the mixer 4c to feed the digital filtering coefficient signal y (k). By adjusting, the artificial sound is adjusted so that the error of the residual noise signal E (k) becomes almost zero.

Accordingly, the second low pass filter 6 performs low pass filtering on the artificial sound output from the real time signal processor 4.

Then, the power amplifier 7 power amplifies the low-pass filtered artificial sound from the second low pass filter 6 and outputs the amplified artificial sound to the acoustic sound field space through the output unit 8.

5 shows an embodiment of an active noise control device.

However, such a conventional active noise control device has a problem in that the manufacturing cost increases when trying to apply to the product because it must have a hardware means (DSP CHIP) for real-time recognition and real-time control of the noise signal.

Accordingly, an object of the present invention is to provide an active noise control device capable of actively controlling noise generated by a motor and other actuators in a home appliance to remove a noise source.

1 is a conceptual diagram of active noise control.

2 is an abnormal signal waveform diagram of an active noise control result.

3 is a block diagram of an active noise control device.

4 is an active noise control block diagram of the real-time signal processor of FIG.

5 is an exemplary view of applying a conventional active noise control device to a refrigerator.

6 is a flowchart of a real-time signal processor control of FIG.

7 is a block diagram of an active noise control device according to the present invention.

8 is an active noise control flowchart by the microcomputer of FIG.

9 is an active noise control block diagram according to FIG.

FIG. 10 is a diagram illustrating control rule and index data network generation of FIG.

* Explanation of symbols for main parts of the drawings

101: sensor unit 101: signal amplification unit

103: first low pass filter 104: phase detector

105: microcomputer unit 106: second low pass filter unit

107: power amplifier 108: output unit

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

7 is a block diagram of the active noise control device according to the present invention, and the sensor unit 101 for detecting the noise signal and the signal amplification to amplify and output the noise signal output from the sensor unit 101 A first low pass filter 103 for low-pass filtering and outputting a noise signal amplified from the signal amplifier 102, and a low pass filtered noise signal from the first low pass filter 103 A phase detector 104 for detecting a phase, a micom unit 105 for real-time processing of a noise signal output from the first low pass filter 103 and the phase detector 104 without phase delay, and the micom A second low pass filter 106 for low-pass filtering and outputting the signal output from the unit 105, and a power amplifying unit for amplifying and outputting the low pass filtered signal output from the second low pass filter 106 ( 107 and electric power from the power amplifier 107. The output unit 108 outputs the amplified signal to the acoustic sound field space.

Referring to Figures 8 and 10 attached to the operation and effect of the present invention configured as described above are as follows.

First, the sensor unit 101 detects and outputs a noise signal X (k) in an acoustic sound field space.

Here, X (k) is a signal input from the microphone. Then, the signal amplifier 102 amplifies and outputs the noise signal X (K) detected by the sensor unit 101.

Accordingly, the first low pass filter 103 performs low pass filtering on the amplified noise signal [X (K)].

Then, the microcomputer 105 interrupts (S1) and converts the low-pass filtered noise signal from the first low pass filter 103 into a digital signal through an internal analog / digital converter (not shown in the accompanying drawings). Done.

In addition, the phase detector 104 detects and outputs the phase of the low-pass filtered noise signal [X (K)] from the first low pass filter 103 (S2).

Then, the microcomputer 105 converts the noise signal [X (K)] into a digital signal through the analog / digital converter (not shown in the accompanying drawings) and converts the converted noise signal [X (K)]. As shown in FIG. 8, the control target system 105a such as a home appliance such as a refrigerator is output.

Then, the control rule adjusting unit 105b in the microcomputer 105 responds to the noise signal [X (K)] by modeling the generated signal through a neural network as shown in FIG. The y (k) signal is output to correspond to the output value one-to-one.

Here, y (k) is an output signal generated from the output unit.

Accordingly, the mixer 105c in the microcomputer 105 mixes the noise signal X (k) output from the control target system 105a with the y (k) signal output from the control rule adjusting unit 105b. The error of the residual noise signal E (k) and the change of the error are calculated and output by the following equation (S3).

E (k) = x (k)-y (k), ΔE (k) = E (k)-E (k-1)

Where E (k) is the error of the residual noise signal and ΔE (k) is the error change signal of the residual noise signal.

In addition, the microcomputer 105 calculates an index table of an internal memory (not shown in the accompanying drawings) in which an inverse phase signal corresponding to the phase signal of the noise signal X (k) is pre-stored. (S4) it is extracted and converted into an analog signal through an internal digital / analog converter (not shown in the accompanying drawings) and output.

Thereafter, the control rule adjusting unit 105b in the microcomputer 105 feeds back the residual noise signal E (k) output from the mixer 105c to adjust the y (k) signal to adjust the residual noise signal E ( k)] error.

Meanwhile, the second low pass filter 106 performs low pass filtering on the analog signal output from the microcomputer 105.

Then, the power amplifier 107 power amplifies the low-pass filtered analog signal from the second low pass filter 106 and outputs the amplified signal to the acoustic sound field space through the output unit 018 (S5). ).

Thereafter, the above operation is continued until the error of the residual noise signal E (k) is eliminated.

As described above, the present invention has the effect of effectively controlling the noise generated by the motor and other actuators (Actuator) in the home appliance to effectively remove the noise source.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active noise control device, and more particularly, to an active noise control device for actively controlling noise generated by a motor and other actuators and the like in a home appliance to remove a noise source.

Claims (1)

A sensor unit 101 for detecting a noise signal, a signal amplifier 102 for amplifying and outputting a noise signal output from the sensor unit 101, and a noise signal amplified from the signal amplifier 102. A first low pass filter 103 for filtering and outputting low pass, a phase detector 104 detecting a phase of the low pass filtered noise signal from the first low pass filter 103, and the first low pass filter ( A microcomputer 105 for real-time processing of the noise signal output from the 103 and the phase detector 104 without phase delay, and a second low pass filter for low-pass filtering the signal output from the microcomputer 105. And a power amplifier 107 for power amplifying and outputting the low pass filtered signal output from the second low pass filter 106, and a signal amplified power from the power amplifier 107. Configured to include an output unit 108 for outputting to the sound field space Active noise control apparatus characterized by.