Please select the most similar patent number from A, B, C and D. Which number is?
A data collection method for continuous physical quantities such as temperature and pressure, comprising: inputting a voltage signal, u, representing a continuous physical quantity; acquiring through an analog sampling channel (1) a sampling signal, u k , of an analog voltage, the sampling frequency being f Δh ; digital low-pass filtering u k  (6) to acquire a voltage signal (ũ k ) that has undergone low-pass filtering; re-sampling (ũ k ) to acquire a re-sampling signal, ũ j , re-sampling frequency, f Δy , being the same as the sampling frequency required by the application end, and the sampling frequency, f Δh , is  M  times the re-sampling frequency, f Δy ; storing and outputting the re-sampling signal, ũ j , to the application end. Provided is a corresponding device. The present invention lowers the cost of analog sampling channels. ū j , replacing ũ j , can be directly applied to industrial automation. In particular, the outputted ũ j  no longer contains a transient value, and can satisfy the input quantity requirements of steady-state models, and can inhibit random interference and enhance measurement precision.
A: An anti-interference processing method during detection of CP signals by vehicle-mounted charger, comprising the following steps: step 1, capturing CP signals; step 2, determining whether the CP signals satisfy a preset pulse width, and reserving qualified CP signals satisfying the preset pulse width; step 3, performing amplitude limiting on the frequencies of the qualified CP signals; step 4, performing average filtering on the amplitude-limited frequencies to obtain smooth sampling frequency values; step 5, performing low-pass filtering on the smooth sampling frequency values; step 6, determining whether the frequency values of the CP signals satisfy Chinese standard requirements, if not, ending the capture, and if yes, calculating a duty cycle so as to continue to perform the next step; and step 7, performing low-pass filtering on the calculated duty cycle to obtain a final CP signal, and ending the capture. By means of the method, a stable CP signal can still be detected while CP signals are severely interfered.
B: A method and device for sampling and compensating a blood pressure detection signal and a blood pressure signal acquisition system. The method comprises: controlling an ECG sampling module (61) and a PPG sampling module (62) to simultaneously sample a standard periodic signal, and obtaining a sampling frequency and a sampling ending time respectively; compensating a sampling start time and the sampling frequency of the ECG sampling module (61) or the PPG sampling module (62), such that a deviation of the sampling frequency is lower than a preset frequency threshold and the difference between the sampling ending times is lower than a preset time threshold.
C: The present invention relates to a steady-state processing method and device for digital measurement or telemetry of an electric power system, including: inputting a data sequence {y k } = {y k , y k-1 ,... y k-N } of the digital measurement or telemetry of a physical quantity y; according to the data sequence {y k }, calculating the n+1 order derivative of y, n = 0, 1,..., until a formula (I) is satisfied, so as to determine n; performing variable substitution with a formula (II), and calculating a data sequence {x k }; judging that a current numerical value x k  is located in a transient-state process or a steady-state process; when the current numerical value x k  is judged to be located in the steady-state process, calculating an average value as a steady-state value according to {x k }; and performing integral inverse transformation, and solving the steady-state value of y from. Also proposed is another steady-state processing method and device for digital measurement or telemetry of an electric power system by adopting a Kalman filter to substitute for the above derivation process. The present invention is applicable to two conditions of the field of digital measurement or telemetry, and performs accurate steady-state processing in the whole process of determining the physical quantity of an electric power system.
D: A variable-sampling rate Fourier analysis method, comprising the following steps: S100, comparing an initially set sampling frequency to preliminarily sample a signal to be analyzed, and then analyzing the fundamental frequency and fundamental amplitude of said signal by means of Fourier analysis; S200, performing preliminary determination on the fundamental amplitude obtained by the analysis, determining a sampling frequency that satisfies the whole cycle truncation, and resampling the signal; S300, performing Fourier analysis on the sampled signal, and using a triple-spectrum-line method to determine an optimal sampling frequency, i.e., an optimal sampling frequency that satisfies the whole cycle truncation and has no spectral leakage; and S400, resampling the signal to obtain the frequency and amplitude of each sub-harmonic. The variable-sampling rate Fourier analysis method can implement high-precision high-frequency signal acquisition and analysis by using a small sampling rate, thereby reducing the cost of the acquisition system and increases the analysis speed.
Answer: C