A weak current signal filtering method, device, electronic equipment and storage medium

Abstract

The present disclosure belongs to the field of signal processing technology, and provides a weak current signal filtering method, system, electronic device and storage medium, the method comprising: dividing the noise into environmental noise, system noise and random noise according to the source of the noise; constructing a system noise model and an environmental noise model according to the environmental noise and the system noise; performing parameter compensation on the environmental noise and the system noise according to the system noise model and the environmental noise model to obtain a compensation value containing the random noise; filtering the random noise in the compensation value to obtain a filtering value of the current transmission signal. The step of selecting the filtering algorithm is removed, and different noise models are constructed according to different noise environments to adapt to different noise environments, thereby improving the filtering effect of the noise.

Description

Technical Field

[0001] The present disclosure belongs to the field of signal processing technology, and in particular relates to a weak current signal filtering method, device, electronic equipment and storage medium. Background Art

[0002] In the process of sensor signal transmission in existing industrial control systems, sensor signals are often distorted due to external environmental noise or system noise. To solve the above problems, two signal filtering methods are usually used at the hardware level or signal processing level: at the hardware level, the key links of the sensor transmission system are protected, such as adding anti-vibration and magnetic protection covers to the sensor transmission link. This method can reduce external environmental noise to a certain extent. At the signal processing level, relevant signal processing algorithms are used to filter or compensate the collected signals, such as using wavelet denoising algorithms to filter out environmental noise. This method requires a certain understanding of the type of noise in order to design a reasonable signal filtering algorithm.

[0003] In the existing technology, signal filtering has the following characteristics: 1) It is necessary to have a good understanding of the noise source and noise type, otherwise it is difficult to select an effective signal filtering algorithm. 2) Existing methods usually use static compensation to deal with system noise, that is, they do not consider the nonlinear effect of the input signal on the system noise. 3) There is no systematic method to analyze the noise and its impact on the signal, resulting in a poor signal filtering effect. Summary of the invention

[0004] To solve the above problems, the present invention provides a weak current signal filtering method and device, which adopts a method of dividing different types of noise and establishing filtering models to filter them separately. It can handle multiple noises simultaneously, adapt to more complex noise environments, and improve the accuracy of signal transmission.

[0005] This application is implemented through the following technical solutions:

[0006] A current transmission signal filtering method, the method comprising:

[0007] According to the source of noise, noise can be divided into environmental noise, system noise and random noise;

[0008] According to the environmental noise and system noise, a system noise model and an environmental noise model are constructed;

[0009] Perform parameter compensation on environmental noise and system noise according to the system noise model and the environmental noise model to obtain a compensation value including random noise;

[0010] The random noise in the compensation value is filtered to obtain a filtered value of the current transmission signal.

[0011] Furthermore, the environmental noise is divided into stable environmental noise and random environmental noise according to whether there is a constant noise source;

[0012] Classify random environmental noise as random noise.

[0013] Furthermore, building a system noise model includes:

[0014] Eliminate environmental noise;

[0015] Input multiple groups of first original values, modulate and process the optical analog signal at the same time, and obtain multiple first measurement values ​​by demodulating and calculating the modulated optical analog signal;

[0016] Calculate a first deviation value according to the first original value and the first measured value;

[0017] generating a system noise model according to the first deviation value and the first measurement value;

[0018] The system noise model is: , where D1 is the first deviation value, I is the first measurement value, and A1 and B2 are calculated by the least squares method.

[0019] Furthermore, an environmental noise model is constructed, including:

[0020] Determine the location of constant noise sources;

[0021] Measure and calculate the three-dimensional distribution value between the sensor system and the constant noise source;

[0022] The collected noise data is normalized according to the distance between the constant noise source and the sensor system to obtain a normalized value;

[0023] Input a second original value, modulate the optical analog signal at the same time, and calculate the average value of the current measurement value within a preset time length according to the demodulated optical analog signal to obtain a second measurement value;

[0024] Calculate a second deviation value according to the second original value and the second measured value;

[0025] Calculate and obtain an environmental noise model according to the second deviation value and the normalized value;

[0026] The environmental noise model is: , where D2 is the second deviation value, Q is the normalized value, and A2 and B2 are calculated by the least squares method.

[0027] Furthermore, noise parameters are compensated according to the system noise model and the environmental noise model, including:

[0028] Input a third original value, modulate the optical analog signal, and obtain a third measured value by demodulating and calculating the modulated optical analog signal;

[0029] Inputting the third original value and the third measured value into the system noise model and the environmental noise model to obtain a third deviation value and a fourth deviation value respectively;

[0030] The third measured value is compensated using the third deviation value and the fourth deviation value to obtain a compensation value.

[0031] Further, the compensation value=the third measurement value+the third deviation value+the fourth deviation value.

[0032] Furthermore, a current transmission signal filtering method further includes:

[0033] A sixth deviation value between the third original value and the filtered value is calculated, and when the sixth deviation value is within a preset deviation range, it is confirmed that the system noise model and the environmental noise model are valid.

[0034] A current transmission signal filtering device, the device comprising:

[0035] A sound source analysis module is used to classify noise into environmental noise, system noise and random noise according to the source of the noise;

[0036] A model building module, used to build a system noise model and an environmental noise model according to the environmental noise and the system noise;

[0037] A noise compensation module is used to perform parameter compensation on system noise and environmental noise according to the system noise model and the environmental noise model to obtain a random noise compensation value;

[0038] The noise filtering module is used to filter the random noise in the compensation value to obtain the filtered value of the current transmission signal.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. Remove the step of selecting the filtering algorithm and build different noise models according to different noise environments to adapt to different noise environments.

[0041] 2. In this application, a system noise model is constructed for the system noise in the transmission system, which eliminates the nonlinear influence of the system noise and improves the filtering effect of the noise.

[0042] 3. Systematically perform parameter compensation and signal filtering on different noises to improve the filtering effect of noise.

[0043] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 The schematic diagram of the prior art process on which the present application is based is shown;

[0046] Figure 2 A schematic diagram of the process flow of the current transmission signal filtering method of the present application is shown;

[0047] Figure 3 A schematic diagram of a process flow for processing different types of noise in a current transmission signal filtering method according to an embodiment of the present disclosure is shown;

[0048] Figure 4 A schematic diagram of a noise processing and model determination process according to an embodiment of the present disclosure is shown;

[0049] Figure 5 A schematic structural diagram of a current transmission signal filtering device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0051] The present invention is as follows Figure 1 The prior art shown serves as a basis:

[0052] Its operation process is:

[0053] One input of the original value and one input of the unmodulated optical analog signal are made to the optical fiber terminal device.

[0054] After being modulated, the optical analog signal is input into a photoelectric signal processing device for demodulation and calculation to obtain a current measurement value.

[0055] like Figure 2 As shown, a weak current signal filtering method according to an embodiment of the present disclosure includes:

[0056] Noise is classified according to its source, which includes system noise, environmental noise and random noise.

[0057] The system noise is generated by factors such as nonlinear input and output or temperature drift of optical devices or electrical devices in the sensing system, and the influence of the system noise on signal transmission has certain regularity.

[0058] The environmental noise is caused by vibration, electromagnetics, and dust in the surrounding environment of the sensor system, and is further divided into stable environmental noise and random environmental noise according to whether there is a constant noise source. The location of the constant noise source is further determined.

[0059] In this embodiment, the random environmental noise is divided into the random noise.

[0060] Among them, the noise sources of the random noise are relatively diverse, including those caused by the environment, the sensor system itself or improper operation during the test. Common random noise types include: single-frequency noise, pulse noise, Gaussian noise, etc. Its characteristics are that the temporal and spatial distribution characteristics of the noise are irregular, but the impact on the accuracy of signal measurement is small.

[0061] like Figure 3 As shown, different processing is performed according to different noise types.

[0062] A system noise model and an environmental noise model are constructed according to the system noise and the environmental noise.

[0063] The environmental noise is excluded, preferably, the first deviation value of the system noise and the system noise model are calculated under the condition of no environmental noise or weak environmental noise.

[0064] The calculation process is:

[0065] A plurality of groups of first original values ​​are connected to the optical fiber terminal device; preferably, the first original value is a constant current value.

[0066] At the same time, the optical fiber terminal device modulates and processes the optical analog signal, and the optical signal processing device demodulates and calculates the modulated optical analog signal to obtain a plurality of first measurement values. The first original value corresponds to the first measurement value one by one.

[0067] Calculate a first deviation value according to the first original value and the first measured value;

[0068] The system noise model is generated by a least square method according to the first deviation value and the first measurement value.

[0069] The system noise model is: , wherein D1 is the first deviation value, I is the first measurement value, and A1 and B2 are calculated by the least squares method.

[0070] According to the constant noise source, a second deviation value and an environmental noise model under the constant noise source are calculated.

[0071] Determine the position of the constant noise source; select a noise monitoring point near the constant noise source, and use a noise sensor to collect noise.

[0072] In this embodiment, the constant noise source is identified based on an empirical method of a person skilled in the art or a noise measurement sensor.

[0073] The three-dimensional distribution value between the sensor system and the constant noise source is measured and calculated. In this process, bilinear, bicubic and other interpolation methods can be used to improve the spatial resolution of the noise field.

[0074] The collected noise data is normalized according to the distance between the constant noise source and the sensor system to obtain a normalized value.

[0075] A second original value is connected to the optical fiber terminal device; preferably, the second original value is a reference current signal of 4mA.

[0076] At the same time, the optical fiber terminal device modulates the optical analog signal, and the optical signal processing device demodulates the modulated optical analog signal to calculate the average value of the measured current value within a preset time length to obtain a second measurement value; wherein, the preset time length is a set value, which is adjusted according to the actual operating environment needs and is a conventional setting during implementation in this field.

[0077] Calculate a second deviation value according to the second original value and the second measured value;

[0078] Calculate the environmental noise model according to the second deviation value and the normalized value;

[0079] The environmental noise model is: , where D2 is the second deviation value, Q is the normalized value, and A2 and B2 are calculated by the least squares method.

[0080] like Figure 4 As shown, the noise is processed and the noise model is verified.

[0081] Noise is parameter-compensated according to the system noise model and the environmental noise model.

[0082] The parameter compensation process is:

[0083] The third original value is connected to the optical fiber terminal device, and the optical analog signal is modulated at the same time. The optoelectronic signal processing device demodulates and calculates the modulated optical analog signal to obtain the third measurement value.

[0084] The third original value and the third measured value are input into the system noise model and the environmental noise model to obtain a third deviation value and a fourth deviation value respectively.

[0085] The third measurement value is compensated using the third deviation value and the fourth deviation value to eliminate the system noise and the environmental noise in the third measurement value, thereby obtaining a compensation value containing the random noise. The compensation value = the third measurement value + the third deviation value + the fourth deviation value.

[0086] The random noise in the compensation value is filtered to obtain a filtered value.

[0087] The filtering algorithm in the filtering process is one or more of median filtering, mean filtering and Gaussian filtering algorithms. The above filtering algorithms are all prior arts commonly known to those skilled in the art.

[0088] A third deviation value between the third original value and the filtered value is calculated, and when the third deviation value is within a preset deviation range, it is confirmed that the system noise model and the environmental noise model are valid.

[0089] Based on the above method, Figure 5 As shown, the embodiment of the present disclosure also provides a weak current signal filtering device corresponding to the above method, the device comprising:

[0090] A sound source analysis module is used to classify noise into environmental noise, system noise and random noise according to the source of the noise;

[0091] A model building module, used to build a system noise model and an environmental noise model according to the environmental noise and the system noise;

[0092] A noise compensation module, used for performing parameter compensation on the system noise and the environmental noise according to the system noise model and the environmental noise model to obtain a compensation value including the random noise;

[0093] The noise filtering module is used to filter the random noise in the compensation value to obtain a filtered value of the current transmission signal.

[0094] Based on the same inventive concept as the above disclosed content, the present disclosure also provides an electronic device accordingly. The electronic device of the present disclosure embodiment includes at least one electrically connected processor and only one memory, the memory is electrically connected to the processor, wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the method as described above.

[0095] It should be noted that the electrical connection between the above-mentioned units does not necessarily mean the connection between lines. An indirect connection method can be applied to the embodiments of the present disclosure as long as the purpose of the present disclosure is achieved.

[0096] Based on the same inventive concept, the present disclosure also provides a computer storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned current transmission signal filtering method is implemented.

[0097] Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A weak current signal filtering method, characterized in that: The method comprises, According to the source of noise, noise can be divided into environmental noise, system noise and random noise; According to the environmental noise and the system noise, a system noise model and an environmental noise model are constructed; wherein, Eliminate the environmental noise; input multiple groups of first original values ​​to the optical fiber terminal device, and at the same time, the optical fiber terminal device modulates and processes the optical analog signal, and the optical signal processing device demodulates the modulated optical analog signal to obtain multiple first measurement values; calculate the first deviation value according to the first original value and the first measurement value; generate the system noise model according to the first deviation value and the first measurement value; A second original value is connected to the optical fiber terminal device, and the optical fiber terminal device modulates the optical analog signal at the same time. The optical signal processing device demodulates the modulated optical analog signal and calculates the average value of the measured current value within a preset time length to obtain a second measurement value; a second deviation value is calculated based on the second original value and the second measurement value; the collected noise data is normalized according to the distance between the constant noise source and the sensor system to obtain a normalized value; the environmental noise model is obtained according to the second deviation value and the normalized value; Performing parameter compensation on the environmental noise and the system noise according to the system noise model and the environmental noise model to obtain a compensation value including the random noise; The random noise in the compensation value is filtered to obtain a filtered value of the current transmission signal.

2. The method according to claim 1, characterized in that The environmental noise is divided into stable environmental noise and random environmental noise according to whether there is a constant noise source; The random environmental noise is divided into the random noise.

3. The method according to claim 1, characterized in that: The system noise model is: , wherein D1 is the first deviation value, I is the first measurement value, and A1 and B1 are calculated by the least squares method.

4. The method according to claim 2, characterized in that: The environmental noise model is: , where D2 is the second deviation value, Q is the normalized value, and A2 and B2 are calculated by the least squares method.

5. The method according to claim 1, characterized in that The performing parameter compensation on noise according to the system noise model and the environmental noise model comprises: Input a third original value, modulate the optical analog signal, and obtain a third measured value by demodulating and calculating the modulated optical analog signal; Inputting the third original value and the third measured value into the system noise model and the environmental noise model to obtain a third deviation value and a fourth deviation value respectively; The third measured value is compensated using the third deviation value and the fourth deviation value to obtain a compensation value.

6. The method according to claim 5, characterized in that The compensation value=the third measurement value+the third deviation value+the fourth deviation value.

7. The method according to claim 5, characterized in that Also includes: A sixth deviation value between the third original value and the filtered value is calculated, and when the sixth deviation value is within a preset deviation range, it is confirmed that the system noise model and the environmental noise model are valid.

8. A weak current signal filtering device, used to implement the method according to any one of claims 1 to 7, characterized in that: The device comprises: A sound source analysis module is used to classify noise into environmental noise, system noise and random noise according to the source of the noise; A model building module, used to build a system noise model and an environmental noise model according to the environmental noise and the system noise; A noise compensation module, used for performing parameter compensation on the environmental noise and the system noise according to the system noise model and the environmental noise model to obtain a compensation value including the random noise; The noise filtering module is used to filter the random noise in the compensation value to obtain a filtered value of the current transmission signal.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

10. A computer storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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