Current sensor based on differential demodulation and PID feedback control and environment compensation method thereof

Abstract

The invention discloses a current sensor based on differential demodulation and PID feedback control and an environment compensation method thereof, and relates to the field of current measurement. According to the current sensor based on differential demodulation and PID feedback control, modulation voltage signal data of a plurality of periods of the current sensor are continuously obtained and preprocessed, the preprocessed modulation voltage signal data of each period of the current sensor are subjected to data analysis, and differential signals of each period of the current sensor are obtained; carrying out demodulation processing to obtain a current change signal of each period of the current sensor; according to the invention, the current change signal of each period of the current sensor is analyzed to obtain the current control index of the current period of the current sensor, the current control index is compared and analyzed with the preset current-driven regulation and control interval, and corresponding regulation and control measures are taken based on the analysis result, so that regulation is carried out according to real-time data, and the regulation and control accuracy is improved. Therefore, the accuracy and the reliability of current measurement are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of current measurement, and specifically to a current sensor based on differential demodulation and PID feedback control and its environmental compensation method. Background Art

[0002] With the rapid development of electronic technology and automatic control, current sensors have been widely used in many fields such as industry, instrumentation, automobiles, and smart homes. As an important measurement tool, current sensors can accurately monitor current changes and ensure the safety and reliability of equipment. However, due to environmental interference, traditional current sensors often have measurement errors, which affect the stability and accuracy of the system. The differential demodulation method can effectively reduce signal errors caused by environmental interference and improve the sensitivity and accuracy of the sensor by finely demodulating the current sensor signal. And PID feedback control uses proportional, integral, and differential control algorithms to optimize the response time and stability of the sensor by adjusting the current signal feedback in real time, thus ensuring the reliability of the measurement results.

[0003] The prior art, such as a Hall current sensor with temperature compensation and its temperature compensation method disclosed in the patent application with publication number CN110687347B, solves the technical problem that the current measurement accuracy of the current Hall current sensor is reduced due to temperature fluctuations. It includes a Hall current chip, a PCB substrate temperature acquisition unit, a level conversion isolation unit, an AD conversion unit, a main control unit, and a signal output unit; the signal output end of the Hall current chip is electrically connected to the signal input end of the level conversion isolation unit; the signal output end of the PCB substrate temperature acquisition unit is electrically connected to the main control unit; the signal output end of the level conversion isolation unit, the AD conversion unit, the main control unit, and the signal output unit are electrically connected in sequence; during the process of the Hall current chip collecting current, the PCB substrate temperature acquisition module continuously monitors the chip temperature change and compensates the current collected by the Hall current chip according to the temperature value, and the obtained current value has high accuracy.

[0004] Based on the above solution, it is found that the limitations of the prior art at least include the following problems. First, the temperature calibration range and current calibration points in the prior art are carried out under a set environment and are only valid under specific calibration conditions. Therefore, when the temperature and current changes in the actual application of the current sensor are large, it is impossible to adjust the compensation in real time dynamically, which affects the measurement accuracy and stability. Second, the prior art lacks dynamic feedback control for real-time current changes, resulting in a large impact of the output current on external environmental changes and making it difficult to adjust adaptively. Finally, in the prior art, the signal of the current sensor is demodulated after level conversion and filtering processing, and the current output cannot be adjusted in time in each cycle, which may cause errors and affect the real-time response and accuracy of the sensor. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a current sensor based on differential demodulation and PID feedback control and its environmental compensation method, which solves the problems that the temperature calibration range and current calibration points in the prior art are carried out under set environments and are only effective under specific calibration conditions. As a result, when the temperature and current change greatly in the actual application of the current sensor, real-time dynamic adjustment and compensation cannot be carried out, thus affecting the measurement accuracy and stability. Secondly, the prior art lacks dynamic feedback control for real-time current changes, which leads to a large influence of the output current by external environmental changes and thus makes it difficult to adaptively adjust. Finally, in the prior art, the signal of the current sensor is demodulated after level conversion and filtering processing, and the output of the current cannot be adjusted in time in each cycle, which may cause errors and thus affect the real-time response and accuracy of the sensor.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A current sensor based on differential demodulation and PID feedback control, comprising: a data acquisition unit, a signal conversion unit, a feedback control unit, and an output regulation unit; the data acquisition unit is used to continuously acquire modulation voltage signal data of several cycles of the current sensor and perform preprocessing, and the modulation voltage signal data is specifically the instantaneous voltage value at each time point; the signal conversion unit is used to perform data analysis on the modulation voltage signal data of each cycle of the preprocessed current sensor to obtain the difference signal of each cycle of the current sensor, and perform demodulation processing to obtain the current change signal of each cycle of the current sensor; the feedback control unit is used to analyze the current change signal of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor, and comprehensively analyze the output current value of each cycle of the current sensor in combination with PID feedback control to obtain the current control index of the current cycle of the current sensor; the output regulation unit is used to compare and analyze the current control index of the current cycle of the current sensor with a preset regulation interval of current drive, and take corresponding regulation measures based on the analysis result.

[0007] Further, the specific steps to obtain the difference signal of each cycle of the current sensor are as follows: comprehensively analyze the instantaneous voltage values at each time point of each cycle of the current sensor to obtain the instantaneous voltage peak value of each cycle of the current sensor, and mark it as the voltage amplitude of each cycle of the current sensor; and analyze the instantaneous voltage values at each time point of each cycle of the current sensor by combining the Fourier transform method to obtain the frequency value and phase value of each cycle of the current sensor; and obtain the first reference voltage signal of each cycle when the current sensor is in an ideal state, where the first reference voltage signal includes a first reference voltage amplitude, a first reference frequency value, and a first reference phase value; comprehensively analyze the voltage amplitude and phase value of each cycle of the current sensor with the reference voltage amplitude and reference phase value of each cycle in the ideal state respectively to obtain the difference amplitude and difference phase value of each cycle of the current sensor, and mark the frequency value of each cycle of the current sensor as the difference frequency value; generate an expression of the difference signal of each cycle of the current sensor based on the difference amplitude, difference phase value, and difference frequency value of each cycle of the current sensor.

[0008] Further, the specific formulas for calculating the difference amplitude and difference phase value of each cycle of the current sensor and the expression of the difference signal are as follows:

[0009] ; where is the difference amplitude of the th cycle of the current sensor, is the voltage amplitude of the th cycle of the current sensor, is the phase value of the th cycle of the current sensor, is the first reference voltage amplitude of the th cycle when the current sensor is in an ideal state, is the first reference phase value of the th cycle when the current sensor is in an ideal state, is the difference phase value of the th cycle of the current sensor, is the th cycle of the difference signal, is the frequency value of the th cycle of the current sensor, is the number of cycles, is the pi.

[0010]

[0010] Further, the specific steps to obtain the current change signal of each cycle of the current sensor are as follows: Analyze the difference signal of each cycle of the current sensor in combination with the Fourier transform method to obtain several frequency components of each cycle of the current sensor; and perform extraction processing on each frequency component of each cycle of the current sensor to obtain the signal frequency value corresponding to each frequency component of each cycle of the current sensor; obtain the cut-off frequency of the frequency signal of each cycle of the current sensor and establish a frequency response function; comprehensively analyze the signal frequency value corresponding to each frequency component of the difference signal of each cycle of the current sensor and the frequency response function in combination with the inverse Fourier transform method to obtain the current change signal of each cycle of the current sensor.

[0011] Further, the specific steps to obtain the current control index of the current cycle of the current sensor are as follows: Comprehensively analyze the current signal of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor; establish a current error function of the current sensor based on the output current value of each cycle of the current sensor and the preset target current value, and obtain the critical gain and cycle duration of the current sensor; analyze the critical gain and cycle duration of the current sensor to obtain the proportional reference coefficient, integral reference coefficient, and differential reference coefficient of the current sensor; adjust and analyze the proportional reference coefficient, integral reference coefficient, differential reference coefficient, and current error function of the current sensor to obtain the current control index of the current cycle of the current sensor.

[0012] Further, the specific formula for calculating the current control index of the current cycle of the current sensor is as follows: ; where is the proportional gain index of the th cycle of the current sensor, is the proportional reference coefficient of the current sensor, is the integral reference coefficient of the current sensor, is the differential reference coefficient of the current sensor, , is the number of cycles.

[0013] Further, the specific steps to obtain the output current value of each cycle of the current sensor are as follows: Read the initial voltage amplitude of the initial voltage signal of each cycle of the current sensor, mark it as the voltage change value of each cycle of the current sensor, and obtain the sensitivity coefficient and initial current value of the current sensor; perform a ratio analysis on the voltage change value of each cycle of the current sensor and the sensitivity coefficient respectively to obtain the output current change value of each cycle of the current sensor, and establish a current change function of the current sensor; comprehensively analyze the initial current value and current change function of the current sensor to obtain the output current value of each cycle of the current sensor;

[0014] Among them, the expression of the current change function of the current sensor and the calculation formula for calculating the output current value of each cycle of the current sensor are as follows: ; among them, is the current change function of the current sensor, is the output current change value of the th cycle of the current sensor, is the output current value of the th cycle of the current sensor, is the initial current value of the current sensor, , is the number of cycles.

[0015] An environmental compensation method for a current sensor based on differential demodulation and PID feedback control includes: obtaining the environmental data of the current cycle of the current sensor, where the environmental data is specifically the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value, and obtaining the temperature value reference value, humidity value reference value, and magnetic field strength value reference value of the current sensor; performing standardization processing on the temperature value reference value, humidity value reference value, magnetic field strength reference value of the current sensor and the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle; comprehensively analyzing the standardized temperature value reference value, humidity value reference value, magnetic field strength value reference value of the current sensor and the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle to obtain the environmental compensation index of the current cycle of the current sensor; comprehensively analyzing the environmental compensation coefficient and current control index of the current cycle of the current sensor to obtain the current correction control index of the current cycle of the current sensor.

[0016] Furthermore, the specific formulas for calculating the environmental compensation index and current correction control index of each cycle of the current sensor are as follows:

[0017] ;

[0018] Among them, is the environmental compensation index of the current cycle of the current sensor, is the temperature value of the current cycle of the current sensor after standardization processing, is the temperature reference value of the current sensor after standardization processing, is the temperature coefficient of the current sensor stored in the database, is the humidity value of the current cycle of the current sensor after standardization processing, is the humidity reference value of the current sensor after standardization processing, is the humidity coefficient of the current sensor stored in the database, is the humidity value magnetic field intensity value of the current sensor after standardization processing for the current cycle, is the magnetic field intensity reference value of the current sensor after standardization processing, is the magnetic field coefficient of the current sensor stored in the database, is the electromagnetic interference value of the current sensor for the current cycle after standardization processing, is the interference coefficient of the current sensor stored in the database, , is the current correction control index of the current sensor for the current cycle, is the current control index of the current sensor for the current cycle, , is the number of cycles, is the natural constant.

[0019] The present invention has the following beneficial effects:

[0020] (1), The current sensor based on differential demodulation and PID feedback control, by introducing the PID control algorithm and real-time feedback mechanism, enables the current sensor to automatically adjust the output according to external changes. The data acquisition unit continuously obtains the modulated voltage signal of the current sensor and adjusts the control strategy through dynamic demodulation and analysis, ensuring that under changing working conditions, the sensor can adaptively adjust the output current, enhancing the real-time response ability and adaptability of the sensor.

[0021] (2), The current sensor based on differential demodulation and PID feedback control, through continuous monitoring and real-time preprocessing of the data acquisition unit, enables the current sensor to accurately capture the instantaneous voltage value of each cycle, and through the signal conversion unit to conduct a detailed analysis of current changes, so that the current measurement can not only reflect the actual current changes, but also be adjusted according to real-time data, thus avoiding measurement errors caused by environmental factors, significantly improving the accuracy and reliability of current measurement.

[0022] (3), The environmental compensation method of the current sensor based on differential demodulation and PID feedback control, by real-time collecting the environmental data of the current sensor for the current cycle and conducting standardization processing with its reference value, can accurately obtain and comprehensively analyze the influence of various environmental factors on current measurement. The introduction of the environmental compensation index ensures that under different environmental conditions, the measurement accuracy of the current sensor is not interfered by external fluctuations, automatically correcting the sensor output, thus ensuring high accuracy and stability in various complex environments, and then improving the adaptability of the sensor in harsh or changing environments, avoiding the decrease in accuracy caused by environmental changes.

[0023] Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all the above-mentioned advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flowchart of a current sensor based on differential demodulation and PID feedback control according to the present invention.

[0025] Figure 2 It is a block diagram of a current sensor based on differential demodulation and PID feedback control according to the present invention.

[0026] Figure 3 It is a flowchart of an environmental compensation method for a current sensor based on differential demodulation and PID feedback control according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In the embodiments of the present application, through a current sensor based on differential demodulation and PID feedback control and its environmental compensation method, the problems in the prior art are solved. The temperature calibration range and current calibration points in the prior art are carried out under a set environment and are only effective under specific calibration conditions. As a result, when the temperature and current in the actual application of the current sensor change greatly, it is impossible to adjust the compensation in real time dynamically, thus affecting the measurement accuracy and stability. Secondly, the prior art lacks dynamic feedback control for real-time current changes, which leads to a large influence of the output current on external environment changes and then makes it difficult to adjust adaptively. Finally, in the prior art, the signal of the current sensor is demodulated after level conversion and filtering processing, and the current output cannot be adjusted in time in each period, which may cause errors and then affect the real-time response and accuracy of the sensor.

[0028] The general idea for the problems in the embodiments of the present application is as follows:

[0029] First, continuously obtain the periodic modulation voltage signal data of the current sensor and perform preprocessing. Then, through the signal conversion unit, perform data analysis on the modulation voltage signal data of each period of the preprocessed current sensor to obtain the difference signal of each period of the current sensor, and perform demodulation processing to obtain the current change signal of each period of the current sensor. Finally, the feedback control unit uses PID feedback control to analyze the current change signal of each period, calculate the current control index, and compare it with the preset current regulation range. According to the comparison result, the regulation unit is output to execute corresponding regulation measures to adjust the current output in real time to ensure that the current value of the sensor is stable within the expected range.

[0030] Please refer to Figure 1 and Figure 2, an embodiment of the present invention provides a technical solution: a current sensor based on differential demodulation and PID feedback control, including the following steps: a data acquisition unit, configured to continuously obtain data of modulation voltage signals at the output end of the current sensor (in this embodiment, the current sensor is a TMR current sensor) for several (signal) cycles (by adding an adaptive control circuit to the output part of the sensor to dynamically adjust the modulation depth (amplitude, frequency or phase) of the output signal in response to external current or magnetic field changes), and perform preprocessing. The modulation voltage signal data is specifically the instantaneous voltage value at each time point (the instantaneous voltage value is the exact value of the voltage signal at a certain moment, obtained by the sampling method, that is, a sampling device (such as an analog-to-digital converter, abbreviated as ADC) samples the voltage signal, the ADC measures and outputs the voltage value, and stores the output voltage value in the database);

[0031] A signal conversion unit, configured to perform data analysis on the modulation voltage signal data of each cycle of the preprocessed current sensor to obtain the difference signal of each cycle of the current sensor, and perform demodulation processing to obtain the current change signal of each cycle of the current sensor;

[0032] A feedback control unit, configured to analyze the current change signal of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor, and comprehensively analyze the output current value of each cycle of the current sensor in combination with PID feedback control to obtain the current control index of the current cycle (i.e., the last cycle obtained) of the current sensor;

[0033] An output regulation unit, configured to compare and analyze the current control index of the current cycle of the current sensor with a preset regulation range of current drive, and take corresponding regulation measures based on the analysis result.

[0034] (If the current control index of the current cycle of the current sensor is within the preset regulation range of current drive, then maintain the current state; if the current control index of the current cycle of the current sensor is lower than the lower limit of the preset regulation range of current drive, then increase the current drive, increase the current output until the current reaches the normal range, and PID control can be used for fine-tuning, gradually increasing the current until the target value is reached; if the current control index of the current cycle of the current sensor is higher than the upper limit of the preset regulation range of current drive, then decrease the current drive, reduce the current output, and check whether there is overload or short circuit in the current sensor).

[0035] Specifically, the specific steps to obtain the difference signal of each cycle of the current sensor are as follows: comprehensively analyze the instantaneous voltage values at each time point of each cycle of the current sensor to obtain the instantaneous voltage peak value of each cycle of the current sensor, and mark it as the voltage amplitude of each cycle of the current sensor; and analyze the instantaneous voltage values at each time point of each cycle of the current sensor by combining the Fourier transform method to obtain the frequency value and phase value of each cycle of the current sensor; and obtain the first reference voltage signal of each cycle when the current sensor is in an ideal state (i.e., the output of the system without external disturbance or current change), and the first reference voltage signal includes the first reference voltage amplitude, the first reference frequency value (the same as the frequency value of the corresponding cycle), and the first reference phase value; comprehensively analyze the voltage amplitude and phase value of each cycle of the current sensor with the reference voltage amplitude and reference phase value of each cycle in the ideal state respectively to obtain the difference amplitude and difference phase value of each cycle of the current sensor, and mark the frequency value of each cycle of the current sensor as the difference frequency value; generate the expression of the difference signal of each cycle of the current sensor based on the difference amplitude, difference phase value, and difference frequency value of each cycle of the current sensor.

[0036] Among them, specifically obtaining the frequency value and phase value of each cycle of the current sensor is as follows: perform Fourier transform analysis on the instantaneous voltage values at each time point of each cycle of the current sensor to obtain several frequency components of each cycle of the current sensor, and combine the statistical method to analyze the amplitude values corresponding to each frequency component of each cycle of the current sensor to obtain the fundamental frequency of each cycle of the current sensor (i.e., the frequency component with the largest corresponding amplitude value), mark it as the frequency value of each cycle of the current sensor, and mark the phase offset corresponding to the fundamental frequency of each cycle of the current sensor as the phase value.

[0037] The first reference voltage signal is the output signal of the sensor measured at a known current value, and the output signal (i.e., the static signal) is measured under the condition of no current input (zero current condition). Through calibration experiments, the input current is changed and the output signal is recorded, so as to establish the relationship between the input and the output, and a reference signal representing the "ideal" state is selected.

[0038] And the specific formulas for calculating the difference amplitude and difference phase value of each cycle of the current sensor and the expression of the difference signal are:

[0039] ; where is the difference amplitude of the th cycle of the current sensor, is the voltage amplitude of the th cycle of the current sensor, is the The phase value of a cycle, is the first reference voltage amplitude of the cycle when the current sensor is in an ideal state, is the first reference phase value of the cycle when the current sensor is in an ideal state, is the differential phase value of the cycle of the current sensor, is the differential signal of the cycle, is the frequency value of the cycle of the current sensor, , is the number of cycles, is pi, which is taken as 3.14 in this embodiment.

[0040] In this embodiment, the frequency and phase values are obtained through Fourier transform, so as to accurately analyze the output signal of the current sensor, accurately judge the change of the signal, and the frequency value and phase value are important parameters characterizing the signal characteristics, which helps to detect the small changes caused by external disturbances or system instability. Secondly, by calculating the differential amplitude and differential phase, the difference between the system output and the ideal reference state can be captured, and the sensitivity and response ability of the measurement system can be further improved. Fourier transform can convert the signal from the time domain to the frequency domain, helping to effectively filter out noise, and then enabling the current sensor to operate stably in a high-noise environment. At the same time, through the accurate measurement of the fundamental frequency and phase offset, the difference between the noise signal and the actual current signal can be effectively distinguished, thereby improving the anti-interference ability. Finally, each cycle of the current sensor is analyzed independently to evaluate the state of each cycle in real time, and using the differential signal expression, the gap between the current sensor and the ideal reference state can be accurately described, providing a quantitative basis for subsequent optimization and adjustment.

[0041] Specifically, the specific steps to obtain the current change signal of each cycle of the current sensor are as follows: Analyze the differential signal of each cycle of the current sensor in combination with the Fourier transform method to obtain several frequency components of each cycle of the current sensor; and perform extraction processing on each frequency component of each cycle of the current sensor to obtain the signal frequency value corresponding to each frequency component of each cycle of the current sensor; obtain the cut-off frequency of the frequency signal of each cycle of the current sensor and establish a frequency response function; combine the inverse Fourier transform method to comprehensively analyze the signal frequency value corresponding to each frequency component of the differential signal of each cycle of the current sensor and the frequency response function to obtain the current change signal of each cycle of the current sensor.

[0042] Among them, the discriminant of the frequency response function is: ; among them, is the frequency response function, the th signal frequency value corresponding to the th frequency component of the cut-off frequency of the frequency signal of the , is the number of periods, , is the number of frequency components.

[0043] Specifically, the Fourier transform method converts the time-domain signal (the difference signal of each period of the current sensor) into the frequency domain, that is, decomposes the complex time-domain signal into a combination of several sine waves (sine waves with different frequencies, amplitudes, and phases), namely frequency components.

[0044] Specifically, the inverse Fourier transform method converts the filtered frequency components (i.e., the frequency components filtered by the frequency response function) back into the time domain, that is, the current change signal.

[0045] In this implementation, the time-domain signal of the current sensor is converted into a frequency-domain signal through the Fourier transform, so as to decompose the complex current change signal into a combination of several sine waves, and each sine wave represents a frequency component in the signal. By extracting these frequency components, precise data support is provided for signal filtering and control. At the same time, the frequency components of each period are extracted and the frequency values of each frequency component are obtained, so as to capture the important frequency information in the current signal. Secondly, by establishing a frequency response function and applying it to each frequency component of the signal, filtering processing is carried out for signals in different frequency ranges, which helps to remove unwanted high-frequency noise or low-frequency drift and retain the effective components in the signal. Secondly, the inverse Fourier transform converts the frequency components processed by the frequency response function back into the time-domain signal, and a smoother and optimized current change signal can be obtained, so that the signal recovery process is more accurate, avoiding possible distortion during the filtering process, and ensuring that the current change signal can reflect the real current change situation. Finally, through the fine extraction and filtering of each frequency component, a higher-quality current change signal is restored, thereby improving the response speed and stability.

[0046] Specifically, the specific steps to obtain the current control index of the current sensor in the current cycle are as follows: comprehensively analyze the current signals of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor; establish a current error function of the current sensor based on the output current value of each cycle of the current sensor and the preset target current value, and obtain the critical gain and cycle duration of the current sensor; analyze the critical gain and cycle duration of the current sensor to obtain the proportional reference coefficient, integral reference coefficient, and differential reference coefficient of the current sensor; adjust and analyze the proportional reference coefficient, integral reference coefficient, differential reference coefficient, and current error function of the current sensor to obtain the current control index of the current sensor in the current cycle.

[0047] Among them, the critical gain is the proportional gain value when the current signal in the current sensor enters the critical oscillation state, which is obtained through the experimental method, that is, set an initial proportional gain, increase the proportional gain, monitor the response of the system, and when the output begins to become unstable and maintain periodic oscillation, record the value of the proportional gain and store it in the database.

[0048] The cycle duration is the time required for the current signal to complete a full oscillation, which is obtained through the sampling method. Sample the signal, use an oscilloscope to monitor the waveform of the signal, and store the time difference from the starting point of one oscillation to the starting point of the next oscillation (i.e., the cycle duration) in the database.

[0049] And the expression of the current error function of the current sensor and the specific formulas for calculating the proportional reference coefficient, integral reference coefficient, and differential reference coefficient of the current sensor are as follows: ; where is the current error function of the current sensor, is the current value of the th cycle of the current sensor, is the current reference value of the current sensor, is the proportional reference coefficient of the current sensor, is the proportionality factor stored in the database, which takes 0.6 in this embodiment, is the critical gain of the current sensor, is the integral reference coefficient of the current sensor, is the integral factor stored in the database, which takes 2 in this embodiment, is the cycle duration of the current sensor, is the differential reference coefficient of the current sensor, is the differential factor stored in the database, which takes 8 in this embodiment, , is the number of cycles.

[0050] The specific formula for calculating the current control index of the current sensor in the current cycle is as follows: ; where is the proportional gain index of the current sensor in the th cycle (i.e., the current cycle), is the proportional reference coefficient of the current sensor, is the integral reference coefficient of the current sensor, is the differential reference coefficient of the current sensor, , is the number of cycles.

[0051] In this embodiment, is the proportional term of the current sensor and is the current error value of the current cycle of the current sensor, is the integral term of the current cycle of the current sensor and is the integral of the current error of the current sensor, is the differential term of the current cycle of the current sensor and is the derivative of the current error of the current sensor.

[0052] In this implementation scheme, by comparing the output current value of the current sensor with the target current value, a current error function is generated, thereby reflecting the deviation between the current output and the target current, providing a basis for subsequent control adjustment, and adjusting the control parameters according to the error magnitude to optimize the current output. And by calculating the proportional, integral, and differential reference coefficients and combining with the current error value of the current cycle, multi-dimensional feedback control of the current is performed to ensure that the current output remains within a stable control range, thereby enhancing the response ability of the current sensor to current changes, being able to quickly correct the current deviation, and improving the accuracy of the current sensor. Secondly, the critical gain and the cycle duration are key parameters for the stability of the current sensor. By determining these parameters through experiments, the critical stability point of the system can be accurately understood, avoiding system oscillation or slow response caused by too high or too low gain, ensuring that the system operates within a stable range. At the same time, by setting the critical gain, the current control state can be monitored in real time and the parameters can be adjusted to prevent the current sensor from entering an unstable state or oscillating, ensuring the stability of the current signal, thereby improving the robustness of the current sensor to external disturbances (such as voltage fluctuations, load changes, etc.), ensuring stable operation under various uncertain conditions. And the sampling and analysis of the cycle duration can help the current sensor identify and adapt to different working loads and operating environments. Finally, the real-time feedback mechanism of the current error enables the current sensor to automatically adjust the control output according to the current error of the current cycle, and then dynamically adjust the control strategy to ensure that the current output always maintains the minimum error with the target value. The integral term helps to eliminate the cumulative error, and the differential term reduces the instantaneous fluctuation, thereby achieving precise current regulation.

[0053] Specifically, the specific steps to obtain the output current value of each cycle of the current sensor are as follows: Read the initial voltage amplitude of the initial voltage signal of each cycle of the current sensor, mark it as the voltage change value of each cycle of the current sensor, and obtain the sensitivity coefficient and initial current value of the current sensor; Perform a ratio analysis on the voltage change value of each cycle of the current sensor with the sensitivity coefficient respectively to obtain the output current change value of each cycle of the current sensor, and establish a current change function of the current sensor; Perform a comprehensive analysis on the initial current value and the current change function of the current sensor to obtain the output current value of each cycle of the current sensor.

[0054] Among them, the expression of the current change function of the current sensor and the calculation formula for obtaining the output current value of each cycle of the current sensor are as follows: ; where is the current change function of the current sensor, is the output current change value of the th cycle of the current sensor, is the output current value of the th cycle of the current sensor, is the initial current value of the current sensor, , is the number of cycles.

[0055] Among them, the sensitivity coefficient is the proportional relationship between the magnetic field change caused by the current change in the TMR current sensor and the output voltage, and is obtained through the TMR current sensor technical specification stored in the database.

[0056] The initial current value is the current value measured by the current sensor without external disturbance or current change, and is obtained through the theoretical model of the circuit, that is, obtain the working voltage and load impedance of the TMR current sensor circuit, then the initial current value = working voltage / load impedance.

[0057] In this embodiment, represents the change amount of the current.

[0058] In this implementation, the voltage change value is combined with the sensitivity coefficient for analysis, so as to accurately convert the voltage signal into the current change value. The sensitivity coefficient, as a key parameter of the TMR (tunnel magnetoresistance) current sensor, can accurately reflect the influence of the current change on the magnetic field and voltage output, so that the current change can be accurately converted into the current change value. The establishment of the current change function can further clarify the current response relationship of the current sensor, thereby ensuring that there is a clear and predictable relationship between the current output value and the voltage change value. At the same time, the sensitivity coefficient of the TMR current sensor reflects the proportional relationship between the magnetic field change and the output voltage, so that the current sensor can accurately respond to small current changes, thereby improving the measurement accuracy. Secondly, through the sensitivity A comprehensive analysis of the sensitivity coefficient and the voltage change value can more accurately calculate the current change value, which in turn helps to further optimize the control system and ensure that the current is stable and works within the specified range. In addition, the method for obtaining the initial current value ensures the output value of the current sensor under ideal conditions without external disturbances, thereby providing a stable benchmark for subsequent current changes, thereby avoiding errors caused by external disturbances, and through the establishment of the current change function, the change of current over time can be accurately simulated, thereby ensuring that the control system can adjust and respond to current fluctuations in real time and maintain current stability. Finally, by combining the current change function with the initial current value for analysis, more precise current control can be achieved, thereby ensuring that the current output value can be consistent with the target current value.

[0059] See also Figure 3 The embodiment of the present invention provides a technical solution: an environmental compensation method for a current sensor based on differential demodulation and PID feedback control, comprising the following steps: obtaining environmental data of the current sensor in the current cycle, the environmental data specifically being temperature value, humidity value, magnetic field strength value, and electromagnetic interference value, and obtaining temperature value reference value, humidity value reference value, and magnetic field strength value reference value of the current sensor; standardizing the temperature value reference value, humidity value reference value, and magnetic field strength reference value of the current sensor as well as the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle; comprehensively analyzing the standardized temperature value reference value, humidity value reference value, and magnetic field strength reference value of the current sensor as well as the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle to obtain the environmental compensation index of the current sensor in the current cycle; comprehensively analyzing the environmental compensation coefficient and current control index of the current sensor in the current cycle to obtain the current correction control index of the current sensor in the current cycle.

[0060] The electromagnetic interference value is the interference intensity of the electromagnetic wave generated by the external or internal source of the TMR current sensor on the sensor signal, which is obtained through an EMI sensor (such as an electromagnetic field detector).

[0061] The magnetic field strength value is the comprehensive magnetic field strength value outside the TMR current sensor, and the magnetic field strength value = 1 / 2 The sum of the squares of the magnetic field strength values in each direction.

[0062] The humidity value reference is the ideal operating humidity of the current sensor under standard environmental conditions, and is obtained from the technical manual of the current sensor stored in the database.

[0063] The magnetic field strength reference is the magnetic field strength value of the current sensor under standard environment, and is obtained from the technical manual of the current sensor stored in the database.

[0064] Specifically, the specific formulas for calculating the environmental compensation index and the current correction control index of each cycle of the current sensor are as follows:

[0065] ;

[0066] Among them, is the environmental compensation index of the current cycle of the current sensor, is the temperature value of the current cycle of the current sensor after normalization, is the temperature reference value of the current sensor after normalization, is the temperature coefficient of the current sensor stored in the database, is the humidity value of the current cycle of the current sensor after normalization, is the humidity reference value of the current sensor after normalization, is the humidity coefficient of the current sensor stored in the database, is the magnetic field strength value of the humidity value of the current cycle of the current sensor after normalization, is the magnetic field strength reference value of the current sensor after normalization, is the magnetic field coefficient of the current sensor stored in the database, is the electromagnetic interference value of the current cycle of the current sensor after normalization, is the interference coefficient of the current sensor stored in the database, , is the current correction control index of the current cycle of the current sensor, is the current control index of the current cycle of the current sensor, , is the number of cycles, is the natural constant, which is taken as 2.71 in this embodiment.

[0067] It should be explained that , , , The specific acquisition process is as follows: Read the temperature value, humidity value, magnetic field intensity value, and electromagnetic interference value of the current sensor in the current cycle after normalization processing, perform summation analysis to obtain the environmental sum value of the current sensor, and perform ratio analysis on the temperature value, humidity value, magnetic field intensity value, and electromagnetic interference value of the current sensor in the current cycle after normalization processing with the environmental sum value respectively, and use the ratio analysis results as the corresponding coefficients.

[0068] Among them, the calculation data examples of the environmental compensation index and current correction control index of the current sensor in the current cycle are as follows in the table: Table 1 Calculation Data Examples of the Environmental Compensation Index and Current Correction Control Index of the Current Sensor in the Current Cycle

[0069] In the table, is the temperature value of the current sensor in the current cycle after normalization processing, is the temperature reference value of the current sensor after normalization processing, is the humidity value of the current sensor in the current cycle after normalization processing, is the humidity reference value of the current sensor after normalization processing, is the magnetic field intensity value of the humidity value of the current sensor in the current cycle after normalization processing, is the magnetic field intensity reference value of the current sensor after normalization processing, is the electromagnetic interference value of the current sensor in the current cycle after normalization processing, is the temperature coefficient of the current sensor stored in the database, is the humidity coefficient of the current sensor stored in the database, is the magnetic field coefficient of the current sensor stored in the database, is the interference coefficient of the current sensor stored in the database, is the environmental compensation index of the current sensor in the current cycle, is the current control index of the current sensor in the current cycle, unit: ampere, is the current correction control index of the current sensor in the current cycle, unit: ampere.

[0070] First set of data: The temperature value of the current sensor after standardization in the current cycle is: 0.624; the temperature reference value of the current sensor after standardization is: 0.584; the humidity value of the current sensor after standardization in the current cycle is: 0.447; the humidity reference value of the current sensor after standardization is: 0.493; the magnetic field intensity value of the humidity value of the current sensor after standardization in the current cycle is: 0.611; the magnetic field intensity reference value of the current sensor after standardization is: 0.546; the electromagnetic interference value of the current sensor after standardization in the current cycle is: 0.422; the temperature coefficient of the current sensor stored in the database is: 0.342; the humidity coefficient of the current sensor stored in the database is: 0.151; the magnetic field coefficient of the current sensor stored in the database is: 0.283; the interference coefficient of the current sensor stored in the database is: 0.234; the environmental compensation index of the current sensor in the current cycle is approximately: 0.141; the current control index of the current sensor in the current cycle is approximately: 0.061 amperes; the current correction control index of the current sensor in the current cycle is approximately: 0.109 amperes.

[0071] Second set of data: The temperature value of the current sensor after standardization in the current cycle is: 0.671; the temperature reference value of the current sensor after standardization is: 0.584; the humidity value of the current sensor after standardization in the current cycle is: 0.472; the humidity reference value of the current sensor after standardization is: 0.493; the magnetic field intensity value of the humidity value of the current sensor after standardization in the current cycle is: 0.585; the magnetic field intensity reference value of the current sensor after standardization is: 0.546; the electromagnetic interference value of the current sensor after standardization in the current cycle is: 0.483; the temperature coefficient of the current sensor stored in the database is: 0.342; the humidity coefficient of the current sensor stored in the database is: 0.151; the magnetic field coefficient of the current sensor stored in the database is: 0.283; the interference coefficient of the current sensor stored in the database is: 0.234; the environmental compensation index of the current sensor in the current cycle is approximately: 0.154; the current control index of the current sensor in the current cycle is approximately: 0.057 amperes; the current correction control index of the current sensor in the current cycle is approximately: 0.102 amperes.

[0072] The third set of data: The temperature value of the current sensor after standardization in the current cycle is: 0.529; the temperature reference value of the current sensor after standardization is: 0.584; the humidity value of the current sensor after standardization in the current cycle is: 0.521; the humidity reference value of the current sensor after standardization is: 0.493; the magnetic field intensity value of the humidity value of the current sensor after standardization in the current cycle is: 0.634; the magnetic field intensity reference value of the current sensor after standardization is: 0.546; the electromagnetic interference value of the current sensor after standardization in the current cycle is: 0.391; the temperature coefficient of the current sensor stored in the database is: 0.342; the humidity coefficient of the current sensor stored in the database is: 0.151; the magnetic field coefficient of the current sensor stored in the database is: 0.283; the interference coefficient of the current sensor stored in the database is: 0.234; the environmental compensation index of the current sensor in the current cycle is approximately: 0.151; the current control index of the current sensor in the current cycle is approximately: 0.067 amperes; the current correction control index of the current sensor in the current cycle is approximately: 0.119 amperes.

[0073] The fourth set of data: The temperature value of the current sensor after standardization in the current cycle is: 0.662; the temperature reference value of the current sensor after standardization is: 0.584; the humidity value of the current sensor after standardization in the current cycle is: 0.488; the humidity reference value of the current sensor after standardization is: 0.493; the magnetic field intensity value of the humidity value of the current sensor after standardization in the current cycle is: 0.597; the magnetic field intensity reference value of the current sensor after standardization is: 0.546; the electromagnetic interference value of the current sensor after standardization in the current cycle is: 0.512; the temperature coefficient of the current sensor stored in the database is: 0.342; the humidity coefficient of the current sensor stored in the database is: 0.151; the magnetic field coefficient of the current sensor stored in the database is: 0.283; the interference coefficient of the current sensor stored in the database is: 0.234; the environmental compensation index of the current sensor in the current cycle is approximately: 0.156; the current control index of the current sensor in the current cycle is approximately: 0.054 amperes; the current correction control index of the current sensor in the current cycle is approximately: 0.096 amperes.

[0074] The fifth set of data: The temperature value of the current sensor after standardization in the current cycle is: 0.558; the temperature reference value of the current sensor after standardization is: 0.584; the humidity value of the current sensor after standardization in the current cycle is: 0.422; the humidity reference value of the current sensor after standardization is: 0.493; the magnetic field intensity value of the current sensor after standardization in the current cycle is: 0.603; the magnetic field intensity reference value of the current sensor after standardization is: 0.546; the electromagnetic interference value of the current sensor after standardization in the current cycle is: 0.458; the temperature coefficient of the current sensor stored in the database is: 0.342; the humidity coefficient of the current sensor stored in the database is: 0.151; the magnetic field coefficient of the current sensor stored in the database is: 0.283; the interference coefficient of the current sensor stored in the database is: 0.234; the environmental compensation index of the current sensor in the current cycle is approximately: 0.139; the current control index of the current sensor in the current cycle is approximately: 0.059 amperes; the current correction control index of the current sensor in the current cycle is approximately: 0.104 amperes.

[0075] In this implementation, by calculating the environmental compensation index and the current correction control index, these environmental impacts can be effectively compensated, thereby improving the measurement accuracy of the current sensor, and further ensuring that the measured current value is more in line with the actual situation. By calculating the current correction control index, more accurate correction parameters can be provided for the control system of the current sensor, and then automatically adjusted according to the real-time environmental changes to maintain the stability and reliability of current control, and avoid measurement errors caused by environmental changes. At the same time, it helps to improve the robustness of the system and reduce the negative impact of external environmental changes on the sensor output. Secondly, through standardization processing and ratio analysis, the performance of the current sensor is optimized according to the actually collected data, so that the output of the current sensor is more accurate, ensuring that the system can perform feedback adjustment according to real-time data. Finally, the calculated environmental compensation and current correction control indices can automatically adjust the current value, reduce human intervention, and improve the efficiency and accuracy of overall control.

[0076] In summary, this application has at least the following effects:

[0077] By introducing the PID control algorithm and the real-time feedback mechanism, the current sensor can automatically adjust its output according to external changes. The data acquisition unit continuously obtains the modulated voltage signal of the current sensor and adjusts the control strategy through dynamic demodulation and analysis, ensuring that under changing working conditions, the sensor can adaptively adjust the output current, enhancing the real-time response ability and adaptability of the sensor.

[0078] Through continuous monitoring and real-time preprocessing by the data acquisition unit, the current sensor can accurately capture the instantaneous voltage value of each cycle, and through the signal conversion unit, a detailed analysis of the current change is carried out. Furthermore, the current measurement can not only reflect the actual current change, but also be adjusted according to real-time data, thus avoiding measurement errors caused by environmental factors, and significantly improving the accuracy and reliability of current measurement.

[0079] By collecting the environmental data of the current sensor in real time for the current cycle and performing standardization processing with its reference value, the influence of various environmental factors on current measurement can be accurately obtained and comprehensively analyzed. The introduction of the environmental compensation index ensures that under different environmental conditions, the measurement accuracy of the current sensor is not interfered by external fluctuations, thus automatically correcting the sensor output, and then ensuring high accuracy and stability in various complex environments, and improving the adaptability of the sensor in harsh or changing environments, avoiding the decrease in accuracy caused by environmental changes.

[0080] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0081] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A current sensor based on differential demodulation and PID feedback control, characterized in that: include: Data acquisition unit, signal conversion unit, feedback control unit, output regulation unit; The data acquisition unit is used to continuously acquire the modulated voltage signal data of several cycles of the current sensor and perform preprocessing, wherein the modulated voltage signal data is specifically the instantaneous voltage value at each time point; The signal conversion unit is used to perform data analysis on the pre-processed modulated voltage signal data of each cycle of the current sensor to obtain a difference signal of each cycle of the current sensor, and perform demodulation processing to obtain a current change signal of each cycle of the current sensor; The feedback control unit is used to analyze the current change signal of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor, and to perform a comprehensive analysis on the output current value of each cycle of the current sensor in combination with the PID feedback control to obtain the current control index of the current sensor in the current cycle; The output control unit is used to compare and analyze the current control index of the current sensor in the current cycle with the preset current drive control interval, and take corresponding control measures based on the analysis result.

2. The current sensor based on differential demodulation and PID feedback control according to claim 1, characterized in that: The specific steps to obtain the difference signal of each cycle of the current sensor are as follows: Comprehensively analyzing the instantaneous voltage value at each time point of each cycle of the current sensor, obtaining the instantaneous voltage peak value of each cycle of the current sensor, and marking it as the voltage amplitude of each cycle of the current sensor; The instantaneous voltage value of each time point of each cycle of the current sensor is analyzed by combining the Fourier transform method to obtain the frequency value and phase value of each cycle of the current sensor; and obtaining a first reference voltage signal of each cycle when the current sensor is in an ideal state, wherein the first reference voltage signal includes a first reference voltage amplitude, a first reference frequency value, and a first reference phase value; The voltage amplitude and phase value of each cycle of the current sensor are comprehensively analyzed with the reference voltage amplitude and reference phase value of each cycle under an ideal state to obtain the difference amplitude and difference phase value of each cycle of the current sensor, and the frequency value of each cycle of the current sensor is marked as the difference frequency value; An expression for a difference signal of each cycle of the current sensor is generated based on the difference amplitude value, the difference phase value, and the difference frequency value of each cycle of the current sensor.

3. The current sensor based on differential demodulation and PID feedback control according to claim 2, characterized in that: The specific formula for calculating the difference amplitude and difference phase value of each cycle of the current sensor and the expression of the difference signal are as follows: ； in, The current sensor The difference in amplitude of the cycles, The current sensor The voltage amplitude of each cycle, The current sensor The phase value of a cycle, The current sensor is in an ideal state. The first reference voltage amplitude of the cycle, The current sensor is in an ideal state. The first reference phase value of the cycle, The current sensor The difference phase value of the cycle, For the The difference signal of the period, The current sensor The frequency value of the cycle, , is the number of cycles, is the ratio of pi.

4. The current sensor based on differential demodulation and PID feedback control according to claim 1, characterized in that: The specific steps to obtain the current change signal of each cycle of the current sensor are as follows: The difference signal of each cycle of the current sensor is analyzed by combining the Fourier transform method to obtain several frequency components of each cycle of the current sensor; and extracting and processing each frequency component of each cycle of the current sensor to obtain a signal frequency value corresponding to each frequency component of each cycle of the current sensor; Obtaining the cutoff frequency of the frequency signal of each cycle of the current sensor and establishing a frequency response function; The signal frequency value and the frequency response function corresponding to each frequency component of the difference signal of each cycle of the current sensor are comprehensively analyzed by combining the inverse Fourier transform method to obtain the current change signal of each cycle of the current sensor.

5. The current sensor based on differential demodulation and PID feedback control according to claim 1, characterized in that: The specific steps of obtaining the current control index of the current sensor in the current cycle are as follows: Comprehensively analyzing the current signal of each cycle of the current sensor to obtain the output current value of each cycle of the current sensor; Establishing a current error function of the current sensor based on the output current value of each cycle of the current sensor and a preset target current value, and obtaining a critical gain and a cycle duration of the current sensor; Analyze the critical gain and cycle duration of the current sensor to obtain the proportional reference coefficient, integral reference coefficient, and differential reference coefficient of the current sensor; The proportional reference coefficient, the integral reference coefficient, the differential reference coefficient, and the current error function of the current sensor are adjusted and analyzed to obtain the current control index of the current sensor in the current cycle.

6. The current sensor based on differential demodulation and PID feedback control according to claim 5, characterized in that: The specific formula for calculating the current control index of the current sensor in the current cycle is as follows: ； in, The current sensor The proportional gain index for each cycle, is the proportional reference coefficient of the current sensor, is the integral reference coefficient of the current sensor, is the differential reference coefficient of the current sensor, , is the number of cycles.

7. The current sensor based on differential demodulation and PID feedback control according to claim 5, characterized in that: The specific steps to obtain the output current value of each cycle of the current sensor are as follows: Reading the initial voltage amplitude of the initial voltage signal of each cycle of the current sensor, marking it as the voltage change value of each cycle of the current sensor, and obtaining the sensitivity coefficient and initial current value of the current sensor; The voltage change value of each cycle of the current sensor is analyzed with the sensitivity coefficient to obtain the output current change value of each cycle of the current sensor, and the current change function of the current sensor is established; Comprehensively analyze the initial current value and current variation function of the current sensor to obtain the output current value of each cycle of the current sensor; Among them, the expression of the current change function of the current sensor and the calculation formula for calculating the output current value of each cycle of the current sensor are as follows: ； in, is the current change function of the current sensor, The current sensor The output current change value of each cycle is: The current sensor The output current value of each cycle is is the initial current value of the current sensor, , is the number of cycles.

8. An environmental compensation method for a current sensor based on differential demodulation and PID feedback control, using the current sensor based on differential demodulation and PID feedback control as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Obtain environmental data of the current cycle of the current sensor, wherein the environmental data specifically includes temperature value, humidity value, magnetic field strength value, and electromagnetic interference value, and obtain a temperature reference value, a humidity reference value, and a magnetic field strength reference value of the current sensor; Standardize the temperature value reference value, humidity value reference value, magnetic field strength reference value of the current sensor and the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle; Comprehensively analyze the standardized temperature value reference value, humidity value reference value, magnetic field strength value reference value of the current sensor and the temperature value, humidity value, magnetic field strength value, and electromagnetic interference value of the current cycle to obtain the environmental compensation index of the current sensor in the current cycle; The environmental compensation coefficient and the current control index of the current sensor in the current cycle are comprehensively analyzed to obtain the current correction control index of the current sensor in the current cycle.

9. The environmental compensation method of the current sensor based on differential demodulation and PID feedback control according to claim 8, characterized in that: The specific formula for calculating the environmental compensation index and current correction control index of each cycle of the current sensor is as follows: ； in, is the ambient compensation index of the current sensor's current cycle, is the temperature value of the current sensor in the current cycle after normalization, is the temperature reference value of the current sensor after standardization, is the temperature coefficient of the current sensor stored in the database, is the humidity value of the current sensor in the current cycle after normalization, is the humidity reference value of the current sensor after standardization, is the humidity coefficient of the current sensor stored in the database, is the humidity value and magnetic field strength value of the current sensor in the current cycle after normalization. is the reference value of the magnetic field strength of the current sensor after standardization, is the magnetic field coefficient of the current sensor stored in the database, is the electromagnetic interference value of the current sensor in the current cycle after normalization, is the interference coefficient of the current sensor stored in the database, , is the current correction control index of the current sensor in the current cycle, is the current control index of the current sensor in the current cycle, , is the number of cycles, is a natural constant.

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