CN112423434A - Power supply ripple based multi-path LED lamp brightness bypass detection device and method - Google Patents

Power supply ripple based multi-path LED lamp brightness bypass detection device and method Download PDF

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CN112423434A
CN112423434A CN202011268498.1A CN202011268498A CN112423434A CN 112423434 A CN112423434 A CN 112423434A CN 202011268498 A CN202011268498 A CN 202011268498A CN 112423434 A CN112423434 A CN 112423434A
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led lamp
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ripple
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CN112423434B (en
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皇甫江涛
洪鑫宇
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Zhejiang University ZJU
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/32—Pulse-control circuits
    • H05B45/325—Pulse-width modulation [PWM]
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    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
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Abstract

The invention discloses a power supply ripple-based multi-channel LED lamp brightness bypass detection device and method. The LED lamp driving circuit comprises an LED lamp, an LED lamp driving circuit, a power supply ripple signal acquisition circuit and a signal processor; LED lamp drive circuit links to each other and control the LED lamp with the LED lamp, a plurality of even has the LED lamp drive circuit of LED lamp and couples and forms multichannel LED lamp on the power, power ripple signal acquisition circuit receives on the power and gathers the power ripple that a plurality of LED lamp drive circuit produced the power, power ripple signal acquisition circuit transmits the power ripple of gathering to signal processor through the USB interface, signal processor can obtain the luminance of every LED lamp after handling mixed ripple signal. The invention relates to a bypass access type device, which realizes the brightness detection of a plurality of paths of LED lamps under the original circuit, and has the advantages of simple structure, low cost and certain universality.

Description

Power supply ripple based multi-path LED lamp brightness bypass detection device and method
Technical Field
The invention relates to a multi-path LED lamp brightness detection method, in particular to a multi-path PWM LED lamp brightness bypass detection device and method based on power supply ripples.
Background
LEDs are solid state electrical light sources and semiconductor lighting devices. Its electrical characteristics are highly discrete. The device has the characteristics of small volume, high mechanical strength, low power consumption, long service life, easy regulation and control and no pollution. PWM is a pulse width modulated signal where the pulse width represents the time of the pulse high level and PWM dimming turns on and off the LED by a PWM wave to change the conduction time of the forward current to achieve the effect of brightness adjustment because the human eye is insensitive to brightness flicker and the average brightness of the LED is observed by the human eye when the PWM wave frequency is greater than 100 Hz.
Present luminance to the LED lamp detects mostly based on the sensor, and uses the drawback of sensor more and more obvious, and it is comparatively general that the sensor is easily influenced by the environment, and the unstable performance in adverse circumstances receives external dust's influence etc. easily. Meanwhile, the sensor needs to be directly installed in the driving circuit when the whole LED circuit is designed, which is not beneficial to updating and upgrading of equipment, so that a bypass detection method and a bypass detection system which are more intelligent and more convenient and can realize brightness detection without changing the structure of the original circuit need to be developed, however, relevant reports are not found at present.
Disclosure of Invention
Aiming at the defects in the background art, the invention aims to provide a power supply ripple-based multi-path PWM LED lamp brightness bypass detection method, aiming at the condition that one power supply drives a plurality of paths of LED lamps, and indirectly detecting the brightness corresponding to each path of LED lamp by utilizing the regular change of different power supply ripples generated by the disturbance of different states of the LED lamps modulated by multi-path PWM on an LED lamp driving circuit.
In order to achieve the purpose, the invention adopts the technical scheme that:
multi-path LED lamp brightness bypass detection device based on power supply ripple
The device comprises an LED lamp, an LED lamp driving circuit, a power supply ripple signal acquisition circuit and a signal processor; LED lamp drive circuit links to each other and controls the LED lamp with the LED lamp, and a plurality of even has the LED lamp drive circuit of LED lamp and couples and form multichannel LED lamp on the power, and power ripple signal acquisition circuit receives on the power and gathers the power ripple that a plurality of LED lamp drive circuit produced the power, and power ripple signal acquisition circuit transmits the power ripple of gathering to signal processor through CH340USB switching mouth, signal processor is computer terminal.
The LED lamp driving circuit comprises a driving circuit power port, a driving circuit output port, an LED lamp positive and negative interface, a PWM signal duty ratio control circuit and an LED lamp working circuit, wherein the PWM signal duty ratio control circuit is connected with the LED lamp working circuit, the LED lamp working circuit is connected with the LED lamp through the driving circuit output port and the LED lamp positive and negative interface in sequence, and the LED lamp driving circuit is connected to a power supply through the driving circuit power port; the duty ratio of the high level and the low level in the PWM wave in the PWM signal duty ratio control circuit is controlled by an external knob or an infrared remote control, so that the working time of the working circuit of the LED lamp is controlled, and the effect of adjusting the brightness of the LED lamp is achieved.
The power supply ripple signal acquisition circuit comprises a filter circuit, a load resistor, a sampling resistor, an AD sampling module and an amplifying circuit; the power supply is connected with a load resistor and a sampling resistor which are connected in series, the two ends of the sampling resistor are connected with an amplifying circuit, the amplifying circuit converts and amplifies weak differential signals at the two ends of the sampling resistor and then outputs the weak differential signals, the amplifying circuit is sequentially connected with a filter circuit, a capacitor and an AD sampling module, and the AD sampling module transmits collected power supply ripples to a signal processor through a CH340 serial port-USB chip.
Second, multi-path LED lamp brightness bypass detection method based on power supply ripple
The method for inputting the mixed ripple signal into the signal processor and processing the mixed ripple signal comprises the following steps:
1) j-layer decomposition is carried out on the mixed ripple signal, and a wavelet coefficient and a scale coefficient of the mixed ripple signal are obtained after decomposition and reconstruction;
the step 1) is specifically as follows:
j-layer decomposition is carried out on the mixed ripple signal by using a complex wavelet function basis of Hilbert transform, a decomposed signal Y is obtained after decomposition and reconstruction, and a wavelet coefficient and a scale coefficient of the mixed ripple signal can be obtained from the decomposed signal Y:
Figure BDA0002776860320000021
wherein d isiFor decomposing the i-th wavelet coefficient, c, in the signal YjTo decompose the jth scale factor in the signal Y.
2) Selecting wavelet coefficient and scale coefficient, establishing signal decomposition matrix, and performing dimensionality reduction reconstruction on the signal decomposition matrix to obtain multi-channel signal
Figure BDA0002776860320000022
The step 2) is specifically as follows:
performing dimensionality reduction reconstruction on the signal decomposition matrix Q to obtain a multi-channel signal
Figure BDA0002776860320000023
Selecting wavelet coefficient d1,d2,...,djAnd a scale factor cjWherein d is1Represents the 1 st wavelet coefficient, d2Representing the 2 nd wavelet coefficient, djExpressing the jth wavelet coefficient, and establishing a signal decomposition matrix Q ═ cj,d1,d2,...,dj]TAnd calculating the eigenvalue Λ ═ λ of the covariance matrix S1,λ2,...,λj+1]And the corresponding feature vector V ═ ω1,ω2,...,ωj+1]：
Figure BDA0002776860320000031
Wherein,
Figure BDA0002776860320000032
u1represents the scale factor cjMean value of u2Representing wavelet coefficients d1Mean value of uj+1Representing wavelet coefficients djT denotes the transposition operation, λ1Represents the 1 st eigenvalue, λ, in the covariance matrix Sj+1Represents the j +1 th eigenvalue, ω, in the covariance matrix S1Represents the 1 st eigenvector, ω, in the covariance matrix Sj+1Representing the j +1 th eigenvector in the covariance matrix S;
let the eigenvalue Λ ═ λ1,λ2,...,λj+1]Sorting from big to small, and selecting in sequenceSelecting N-1 eigenvalues, wherein N represents the number of LED lamps, selecting N-1 signal components with eigenvalue serial numbers corresponding to the N-1 eigenvalues from the signal decomposition matrix Q, and forming a multi-channel signal together with the mixed ripple signal
Figure BDA0002776860320000033
3) Combining multiple channel signals
Figure BDA0002776860320000034
Whitening processing is carried out to obtain whitened multichannel signal
Figure BDA0002776860320000035
Randomly assigning initial values to the separation matrix M using whitened multichannel signals
Figure BDA0002776860320000036
Continuously iterating the separation matrix M to the previous separation matrix Mk-1From the current separation matrix MkSatisfies sigma Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma; wherein σ is an error, and satisfies 0<σ<1, k is the number of iterations of the separation matrix M, Σ | Mk-Mk-1I denotes a separation matrix MkAnd a separation matrix Mk-1Obtaining an intermediate matrix after difference is made, and summing all elements in the intermediate matrix to obtain a result; calculating to obtain original multi-channel signal
Figure BDA0002776860320000037
Figure BDA0002776860320000038
Wherein O (t) ═ O1(t),O2(t),···,ON(t)]，O1(t) represents the 1 st original channel signal, and N represents the total N LED lamps;
the step 3) is specifically as follows:
combining multiple channel signals
Figure BDA0002776860320000039
By usingWhitening processing is carried out by the following formula to obtain whitened multichannel signal
Figure BDA00027768603200000310
Figure BDA00027768603200000311
Randomly assigning an initial value to the separation matrix M, and continuously iterating the separation matrix M to the previous separation matrix M by using the following formulak-1From the current separation matrix MkError of (2) satisfies | Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma;
Figure BDA00027768603200000312
Figure BDA00027768603200000313
Figure BDA00027768603200000314
Figure BDA00027768603200000315
wherein,
Figure BDA0002776860320000041
the function of the cumulative distribution is represented,
Figure BDA0002776860320000042
representing a probability distribution function, mk-1Represents a row in the separation matrix M obtained in the (k-1) th iteration, and y represents the whitened multi-channel signal
Figure BDA0002776860320000043
M andk-1the same line sequence numberOne row of (1), mkDenotes M and M in the separation matrix M obtained in the k-th iterationk-1One line of the same line sequence number, Mk-1Representing the separation matrix M, M obtained by the k-1 th iteration calculationkRepresenting a separation matrix M obtained by the k-th iterative computation, wherein E { } represents an expected operation, and T represents a transposition operation;
finally, the original multi-channel signal is calculated
Figure BDA0002776860320000044
4) Converting each sub-original channel signal in the original multi-channel signal O (t) into a square wave signal, calculating the duty ratio of each square wave signal, and forming a total duty ratio q ═ q1,q2,...,qN]And obtaining the brightness L of the N LED lamps [ L ] from the total duty ratio q1,L2,...,LN]The duty ratio corresponds to the brightness of the LED lamp in equal proportion, and when the duty ratio is 1, the LED lamp is in the brightest working state; when the duty ratio is 0, the LED lamp is completely extinguished.
The invention has the following effective benefits:
the invention discloses a power supply ripple-based multi-channel PWM (pulse width modulation) LED lamp brightness bypass detection device and method, which are different from the traditional sensor-based LED lamp brightness detection method, and the brightness corresponding to each channel of LED lamp is indirectly detected by using the regular change of different power supply ripples generated by the disturbance of different states of a PWM LED lamp on an LED lamp driving circuit.
The invention designs a multipath PWM LED lamp brightness bypass detection device based on power supply ripples, which is used as a bypass access type system, realizes the brightness detection of multipath PWM LEDs under the condition of not changing the original circuit, has simple system structure, low realization cost, wide application range and certain universality, and provides another idea by combining the ubiquitous power internet of things and the non-sensing detection based on the power supply ripples.
Drawings
FIG. 1 is a block schematic diagram of an embodiment of the invention;
FIG. 2 is a block diagram of the architecture of an embodiment of the present invention;
FIG. 3 is a schematic diagram of a PWM signal duty cycle control circuit interface;
FIG. 4 is a circuit diagram of a power supply ripple signal acquisition circuit;
FIG. 5 is a flow chart of a signal processing algorithm of the signal processor;
in the figure: 1. the LED lamp comprises an LED lamp body, 2 an LED lamp driving circuit, 3 a power supply ripple signal acquisition circuit, 4 a signal processor, 5 a power supply, 6 a driving circuit power port, 7 a PWM signal duty ratio control circuit, 8 a driving circuit output port, 9 an LED lamp positive and negative interface, 10 an LED lamp working circuit, 11 a filter circuit, 12 a load resistor, 13 a sampling resistor, 14 an AD sampling module, 15 and an amplifying circuit.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
As shown in fig. 1 and 2, the invention includes an LED lamp 1, an LED lamp driving circuit 2, a power supply ripple signal acquisition circuit 3 and a signal processor 4; LED lamp drive circuit 2 links to each other and controls LED lamp 1 with LED lamp 1, a plurality of LED lamp drive circuit 2 that even has LED lamp 1 forms the multichannel LED lamp on hookup to power 5, power ripple signal acquisition circuit 3 receives on power 5 and gathers the power ripple that a plurality of LED lamp drive circuit 2 produced power 5, power ripple signal acquisition circuit 3 transmits the power ripple of gathering to signal processor 4 through CH340USB switching mouth, signal processor 4 is computer terminal.
The LED lamp driving circuit 2 comprises a driving circuit power port 6, a driving circuit output port 8, an LED lamp positive and negative interface 9, a PWM signal duty ratio control circuit 7 and an LED lamp working circuit 10, wherein the PWM signal duty ratio control circuit 7 is connected with the LED lamp working circuit 10, the LED lamp working circuit 10 is connected with the LED lamp 1 sequentially through the driving circuit output port 8 and the LED lamp positive and negative interface 9, and the LED lamp driving circuit 2 is connected to a power supply 5 through the driving circuit power port 6; the duty ratio of the high level and the low level in the PWM wave in the PWM signal duty ratio control circuit 7 is controlled by an external knob or an infrared remote control, so that the working time of the LED lamp working circuit 10 is controlled, and the effect of adjusting the brightness of the LED lamp 1 is achieved.
The PWM signal duty ratio control circuit selects a duty ratio adjustable square wave signal generating circuit which is easily purchased in the market, a PWM pulse module with a liquid crystal display of telesky company is selected in the implementation of the invention, three PWM signal generators output 50Hz, 200Hz and 600Hz equal-amplitude PWM waves to a working circuit of an LED lamp, and in the specific implementation, the LED lamp driving circuit 2 selects three paths, namely the number of the LED lamps is three.
As shown in fig. 4, the power supply ripple signal acquisition circuit 3 includes a filter circuit 11, a load resistor 12, a sampling resistor 13, an AD sampling module 14, and an amplifying circuit 15; the load resistor 12 and the sampling resistor 13 which are connected in series are connected between the power supplies 5, two ends of the sampling resistor 13 are connected with the amplifying circuit 15, the amplifying circuit 15 converts and amplifies weak differential signals at two ends of the sampling resistor 13 and then outputs the signals, the amplifying circuit 15 is sequentially connected with the filter circuit 11, the capacitor and the AD sampling module 14, and the AD sampling module 14 transmits collected power supply ripples to the signal processor 4 through a CH340 serial port-USB chip.
In a specific implementation, the load resistor 12 is 120 Ω, the sampling resistor 13 is 1 Ω, and the non-inverting input amplifiers a1 and a2 based on OP27 are selected, and the non-inverting inputs of the non-inverting input amplifiers a1 and a2 are used to amplify the input resistor. The differential amplifier a3 based on INA105 converts a differential input signal into a single-ended output signal, improves the common mode rejection ratio of the amplifier circuit 15, i.e., rejects the common mode, amplifies differential mode gain, and rejects noise. According to circuit principles, the differential mode gain of the amplifier is calculated:
Avd＝1+2R3/RX
where Avd represents the voltage amplification. In the embodiment of the invention, a sliding rheostat with the resistance R3 of 5k omega is selected, and the resistance R4 of 20k omega is selected, so that the magnification is 9 times at least.
The filter circuit 11 uses a second-order low-pass filter based on OP27 to filter out high-frequency noise, thereby smoothing the waveform. The cut-off frequency f of the second-order RC low-pass filter is directly related to the second-order RC low-pass filter as follows:
Figure BDA0002776860320000061
in the example, the selected resistor R5 ═ R6 ═ 5k Ω, and the selected capacitor C1 ═ C2 ═ 0.01uF, and the cutoff frequency f of the second-order RC low-pass filter is calculated to be 1190 kHz.
The AD sampling module 14 selects internal ADC resources of an STM32F103 series single chip microcomputer of ST company, the AD sampling module 14 transfers acquired sampling data to an internal memory through internal DMA of STM32, the burden of a CPU is reduced, meanwhile, the stability and the accuracy of AD sampling are enhanced, the sampling data, namely, a mixed ripple signal is transmitted to the signal processor 4 through UART serial communication by converting an onboard CH340 serial port into a USB chip, and the sampling frequency is 10kHz in the specific implementation of the invention, so that the Nyquist sampling frequency theorem is met.
As shown in fig. 5, the method for processing the mixed ripple signal by inputting the mixed ripple signal into the signal processor 4 includes the following steps:
1) j-layer decomposition is carried out on the mixed ripple signal, and a wavelet coefficient and a scale coefficient of the mixed ripple signal are obtained after decomposition and reconstruction;
the step 1) is specifically as follows:
j-layer decomposition is carried out on the mixed ripple signal by using a complex wavelet function basis of Hilbert transform, a decomposed signal Y is obtained after decomposition and reconstruction, and a wavelet coefficient and a scale coefficient of the mixed ripple signal can be obtained from the decomposed signal Y:
Figure BDA0002776860320000062
wherein d isiFor decomposing the i-th wavelet coefficient, c, in the signal YjTo decompose the jth scale factor in the signal Y.
In a specific implementation, j is 4, and the corresponding signal component is obtained as follows:
Figure BDA0002776860320000063
2) selecting wavelet coefficient and scale coefficient, establishing signal decomposition matrix, and decomposing signal matrixPerforming dimensionality reduction reconstruction to obtain a multi-channel signal
Figure BDA0002776860320000064
The step 2) is specifically as follows:
performing dimensionality reduction reconstruction on the signal decomposition matrix Q to obtain a multi-channel signal
Figure BDA0002776860320000065
Selecting wavelet coefficient d1,d2,...,djAnd a scale factor cjWherein d is1Represents the 1 st wavelet coefficient, d2Representing the 2 nd wavelet coefficient, djExpressing the jth wavelet coefficient, and establishing a signal decomposition matrix Q ═ cj,d1,d2,...,dj]TAnd calculating the eigenvalue Λ ═ λ of the covariance matrix S1,λ2,...,λj+1]And the corresponding feature vector V ═ ω1,ω2,...,ωj+1]：
Figure BDA0002776860320000071
Wherein,
Figure BDA0002776860320000072
u1represents the scale factor cjMean value of u2Representing wavelet coefficients d1Mean value of uj+1Representing wavelet coefficients djT denotes the transposition operation, λ1Represents the 1 st eigenvalue, λ, in the covariance matrix Sj+1Represents the j +1 th eigenvalue, ω, in the covariance matrix S1Represents the 1 st eigenvector, ω, in the covariance matrix Sj+1Representing the j +1 th eigenvector in the covariance matrix S;
let the eigenvalue Λ ═ λ1,λ2,...,λj+1]Sorting from big to small, sequentially selecting N-1 eigenvalues, wherein N represents the number of LED lamps, and selecting N-1 eigenvalues from a signal decomposition matrix QThe N-1 signal components of the corresponding characteristic value serial numbers and the mixed ripple signals jointly form a multi-channel signal
Figure BDA0002776860320000073
In a specific implementation, the signal decomposition matrix Q ═ c4,d1,d2,d3,d4]TFirstly, calculating a mean vector of each signal component of the signal decomposition matrix Q:
Figure BDA0002776860320000074
Figure BDA0002776860320000075
Figure BDA0002776860320000076
Figure BDA0002776860320000077
Figure BDA0002776860320000078
where L is the length of the signal component.
Eigenvalues Λ ═ λ of the covariance matrix S1,λ2,...,λ5]And the corresponding feature vector V ═ ω1,ω2,...,ω5](ii) a Let the eigenvalue Λ ═ λ1,λ2,...,λ5]Sorting from big to small, sequentially selecting 2 eigenvalues, selecting 2 signal components with eigenvalue serial numbers corresponding to the 2 eigenvalues from the signal decomposition matrix Q, and forming a multi-channel signal together with the mixed ripple signal
Figure BDA0002776860320000081
3) Combining multiple channel signals
Figure BDA0002776860320000082
Whitening processing is carried out to obtain whitened multichannel signal
Figure BDA0002776860320000083
Randomly assigning initial values to the separation matrix M using whitened multichannel signals
Figure BDA0002776860320000084
Continuously iterating the separation matrix M to the previous separation matrix Mk-1From the current separation matrix MkSatisfies sigma Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma; wherein σ is an error, and satisfies 0<σ<1, k is the number of iterations of the separation matrix M, Σ | Mk-Mk-1I denotes a separation matrix MkAnd a separation matrix Mk-1Obtaining an intermediate matrix after difference is made, and summing all elements in the intermediate matrix to obtain a result; calculating to obtain original multi-channel signal
Figure BDA0002776860320000085
Figure BDA0002776860320000086
Wherein O (t) ═ O1(t),O2(t),···,ON(t)]，O1(t) represents the 1 st original channel signal, namely the original channel signal generated by the 1 st LED lamp, and N represents the total N LED lamps;
the step 3) is specifically as follows:
combining multiple channel signals
Figure BDA0002776860320000087
Whitening processing is carried out by adopting the following formula to obtain a whitened multichannel signal
Figure BDA0002776860320000088
Figure BDA0002776860320000089
Randomly assigning an initial value to the separation matrix M, and continuously iterating the separation matrix M to the previous separation matrix M by using the following formulak-1From the current separation matrix MkSatisfies sigma Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma;
Figure BDA00027768603200000810
Figure BDA00027768603200000811
Figure BDA00027768603200000812
Figure BDA00027768603200000813
wherein,
Figure BDA00027768603200000814
the function of the cumulative distribution is represented,
Figure BDA00027768603200000815
representing a probability distribution function, mk-1Represents a row in the separation matrix M obtained in the (k-1) th iteration, and y represents the whitened multi-channel signal
Figure BDA00027768603200000816
M andk-1one line of the same line sequence number, mkDenotes M and M in the separation matrix M obtained in the k-th iterationk-1One line of the same line sequence number, Mk-1Representing the separation matrix M, M obtained by the k-1 th iteration calculationkRepresenting the separation moment calculated in the k-th iterationThe matrix M, E { } represents the expected operation, and T represents the transposition operation;
finally, the original multi-channel signal is calculated
Figure BDA00027768603200000817
4) Converting each sub-original channel signal in the original multi-channel signal O (t) into a square wave signal, calculating the duty ratio of each square wave signal, and forming a total duty ratio q ═ q1,q2,···,qN]And obtaining the brightness L of the N LED lamps [ L ] from the total duty ratio q1,L2,···,LN]The duty ratio corresponds to the brightness of the LED lamp in equal proportion, and when the duty ratio is 1, the LED lamp is in the brightest working state; when the duty ratio is 0, the LED lamp is completely extinguished.
In a specific implementation, the total duty cycle q is [ q ═ q1,q2,q3]The brightness L of the corresponding three LED lamps is ═ L1,L2,L3]。

Claims (7)

1. The utility model provides a multichannel LED lamp luminance bypass detection device based on power ripple which characterized in that: the LED power supply comprises an LED lamp (1), an LED lamp driving circuit (2), a power supply ripple signal acquisition circuit (3) and a signal processor (4); LED lamp drive circuit (2) link to each other and control LED lamp (1) with LED lamp (1), a plurality of even has LED lamp drive circuit (2) of LED lamp (1) and forms multichannel LED lamp on hookup power (5), power ripple signal acquisition circuit (3) are received on power (5) and are gathered power ripple that a plurality of LED lamp drive circuit (2) produced power (5), power ripple signal acquisition circuit (3) transmit the power ripple of gathering to signal processor (4) through the USB switching mouth.
2. The power supply ripple-based multi-path LED lamp brightness bypass detection device according to claim 1, wherein: the LED lamp driving circuit (2) comprises a PWM signal duty ratio control circuit (7) and an LED lamp working circuit (10), the PWM signal duty ratio control circuit (7) is connected with the LED lamp working circuit (10), and the LED lamp working circuit (10) is connected with the LED lamp (1); the duty ratio of the high level and the low level in the PWM wave in the PWM signal duty ratio control circuit (7) is controlled by an external knob or infrared remote control, so that the working time of the LED lamp working circuit (10) is controlled, and the effect of adjusting the brightness of the LED lamp (1) is achieved.
3. The power supply ripple-based multi-path LED lamp brightness bypass detection device according to claim 1, wherein: the power supply ripple signal acquisition circuit (3) comprises a filter circuit (11), a load resistor (12), a sampling resistor (13), an AD sampling module (14) and an amplifying circuit (15); load resistance (12) and sampling resistor (13) that are connected with the series between power (5), the both ends and amplifier circuit (15) of sampling resistor (13) are connected, and amplifier circuit (15) link to each other with filter circuit (11), electric capacity, AD sampling module (14) in proper order, and AD sampling module (14) change the power ripple transmission to signal processor (4) that the USB chip will gather through the CH340 serial ports.
4. A power supply ripple-based multi-path LED lamp brightness bypass detection method applied to the multi-path LED lamp brightness bypass detection device of any one of claims 1 to 3 is characterized in that: the mixed ripple signal is input into the signal processor (4), and the method for processing the mixed ripple signal comprises the following steps:
1) j-layer decomposition is carried out on the mixed ripple signal, and a wavelet coefficient and a scale coefficient of the mixed ripple signal are obtained after decomposition and reconstruction;
2) selecting wavelet coefficient and scale coefficient, establishing signal decomposition matrix, and performing dimensionality reduction reconstruction on the signal decomposition matrix to obtain multi-channel signal
Figure FDA0002776860310000011
3) Combining multiple channel signals
Figure FDA0002776860310000012
Whitening processing is carried out to obtain whitened multichannel signal
Figure FDA0002776860310000013
To the separation matrix M randomAssigning initial values using whitened multichannel signals
Figure FDA0002776860310000014
Continuously iterating the separation matrix M to the previous separation matrix Mk-1From the current separation matrix MkSatisfies sigma Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma; wherein σ is an error, and satisfies 0<σ<1, k is the number of iterations of the separation matrix M, Σ | Mk-Mk-1I denotes a separation matrix MkAnd a separation matrix Mk-1Obtaining an intermediate matrix after difference is made, and summing all elements in the intermediate matrix to obtain a result; calculating to obtain original multi-channel signal
Figure FDA0002776860310000021
Figure FDA0002776860310000022
Wherein O (t) ═ O1(t),O2(t),···,ON(t)]，O1(t) represents the 1 st original channel signal, and N represents the total N LED lamps;
4) converting each sub-original channel signal in the original multi-channel signal O (t) into a square wave signal, calculating the duty ratio of each square wave signal, and forming a total duty ratio q ═ q1,q2,···,qN]And obtaining the brightness L of the N LED lamps [ L ] from the total duty ratio q1,L2,···,LN]The duty ratio corresponds to the brightness of the LED lamp in equal proportion, and when the duty ratio is 1, the LED lamp is in the brightest working state; when the duty ratio is 0, the LED lamp is completely extinguished.
5. The method of claim 4, wherein the method comprises the following steps: the step 1) is specifically as follows:
j-layer decomposition is carried out on the mixed ripple signal by using a complex wavelet function basis of Hilbert transform, a decomposed signal Y is obtained after decomposition and reconstruction, and a wavelet coefficient and a scale coefficient of the mixed ripple signal can be obtained from the decomposed signal Y:
Figure FDA0002776860310000023
wherein d isiFor decomposing the i-th wavelet coefficient, c, in the signal YjTo decompose the jth scale factor in the signal Y.
6. The method of claim 5, wherein the method comprises the following steps: the step 2) is specifically as follows:
performing dimensionality reduction reconstruction on the signal decomposition matrix Q to obtain a multi-channel signal
Figure FDA0002776860310000024
Selecting wavelet coefficient d1,d2,···,djAnd a scale factor cjWherein d is1Represents the 1 st wavelet coefficient, d2Representing the 2 nd wavelet coefficient, djExpressing the jth wavelet coefficient, and establishing a signal decomposition matrix Q ═ cj,d1,d2,···,dj]TAnd calculating the eigenvalue Λ ═ λ of the covariance matrix S1,λ2,...,λj+1]And the corresponding feature vector V ═ ω1,ω2,…,ωj+1]：
Figure FDA0002776860310000025
Wherein,
Figure FDA0002776860310000026
u1represents the scale factor cjMean value of u2Representing wavelet coefficients d1Mean value of uj+1Representing wavelet coefficients djT denotes the transposition operation, λ1Represents the 1 st eigenvalue, λ, in the covariance matrix Sj+1Representing covarianceThe j +1 th eigenvalue, ω, in the matrix S1Represents the 1 st eigenvector, ω, in the covariance matrix Sj+1Representing the j +1 th eigenvector in the covariance matrix S;
let the eigenvalue Λ ═ λ1,λ2,...,λj+1]Sorting from big to small, sequentially selecting N-1 eigenvalues, wherein N represents the number of LED lamps, and selecting N-1 signal components of eigenvalue serial numbers corresponding to the N-1 eigenvalues from the signal decomposition matrix Q to form a multi-channel signal together with the mixed ripple signal
Figure FDA0002776860310000031
7. The method of claim 6, wherein the method comprises the following steps: the step 3) is specifically as follows:
combining multiple channel signals
Figure FDA0002776860310000032
Whitening processing is carried out by adopting the following formula to obtain a whitened multichannel signal
Figure FDA0002776860310000033
Figure FDA0002776860310000034
Randomly assigning an initial value to the separation matrix M, and continuously iterating the separation matrix M to the previous separation matrix M by using the following formulak-1From the current separation matrix MkSatisfies sigma Mk-Mk-1Obtaining a final separation matrix M, wherein | < sigma;
Figure FDA0002776860310000035
Figure FDA0002776860310000036
Figure FDA0002776860310000037
Figure FDA0002776860310000038
wherein,
Figure FDA0002776860310000039
the function of the cumulative distribution is represented,
Figure FDA00027768603100000310
representing a probability distribution function, mk-1Represents a row in the separation matrix M obtained in the (k-1) th iteration, and y represents the whitened multi-channel signal
Figure FDA00027768603100000311
M andk-1one line of the same line sequence number, mkDenotes M and M in the separation matrix M obtained in the k-th iterationk-1One line of the same line sequence number, Mk-1Representing the separation matrix M, M obtained by the k-1 th iteration calculationkRepresenting a separation matrix M obtained by the k-th iterative computation, wherein E { } represents an expected operation, and T represents a transposition operation;
finally, the original multi-channel signal is calculated
Figure FDA00027768603100000312
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CN208445795U (en) * 2018-05-29 2019-01-29 中国石油天然气集团有限公司 The Adaptive Suppression circuit and LED light source driving circuit of remnants ripple electric current

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Publication number Priority date Publication date Assignee Title
KR101452240B1 (en) * 2012-12-14 2014-10-22 (주)세종하이테크 Circuit for reducing Direct Current ripple for LED lighting apparatus
CN104812121A (en) * 2014-01-27 2015-07-29 通用电气公司 LED driving circuit
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