一阶RC低通滤波

计算流程

代码

import numpy as np
from matplotlib import pyplot as plt
from matplotlib.pylab import mpl
zhfont = mpl.font_manager.FontProperties(fname='C:\\Windows\\Fonts\\simsun.ttc')
fontcn = {'fontproperties': zhfont, 'size': 20, 'color': 'red'}
mpl.rcParams['font.sans-serif'] = ['SimHei']  # 显示中文
mpl.rcParams['axes.unicode_minus'] = False  # 显示负号
#     入口：NEW_DATA 新采样值，OLD_DATA 上次滤波结果，k滤波系数
#     出口:本次滤波结果

def filter_1(NEW_DATA,OLD_DATA, k):
    if NEW_DATA < OLD_DATA:
        result = OLD_DATA - abs(OLD_DATA-NEW_DATA) * k
    elif NEW_DATA > OLD_DATA:
        result = OLD_DATA + abs(OLD_DATA - NEW_DATA) * k
    else:
        result = OLD_DATA
    return result


if __name__ == "__main__":
    R = 1000
    C = 4.7
    tao = R*C
    t = 1800
    k = t / tao
    q2 = np.zeros((1, 500))
    for i in range(3, 200):
        q2[0, i] = 20 + 3*np.sin(0.3*i)
    for i in range(200, 500):
        q2[0, i] = 25 + 3*np.sin(0.3*i)
    q2[0, 0] = 0
    q2[0, 1] = 5
    q2[0, 2] = 11
    record = []
    OLD_DATA = 0
    for i in range(1, 500):
        OLD_DATA = filter_1(q2[0, i], OLD_DATA, k)
        record.append(OLD_DATA)
    record.insert(0, 0)
    _x = range(1, 501)
    _x1 = np.zeros((1, 500))
    for i in range(500):
        _x1[0, i] = i+1
    plt.figure(figsize=(40,24), dpi=200)
    plt.plot(list(_x), record, "o:", markersize=1)
    plt.plot(_x1, q2, "*:", markersize=1)
    plt.xlabel('采样次数', fontcn)
    plt.ylabel('数值', fontcn)
    plt.tick_params(labelsize=20)
    plt.legend(['滤波效果', '采样值'])
    plt.savefig('一阶RC低通滤波.jpg')
    plt.show()

滤波效果