phase_相位差_相位检测_dft相位差_相位误差_probablyjss_

% NC, 2017-08-26. clear; clc; close all; %% Basic parameters fs = 400e6; % sampling rate: 400MHz f = 20e6; % basic signal frequency: 20MHz f_ref = 20e6+10 ; % reference signal frequency lambda = 780e-9; % wavelength:780nm v_max = 1.53; % the maximum velocity: 1.53m/s N = 1000; % the cutoff parameter for filtered signal %% Reference signal t0 = (1/fs):(1/fs):0.01; s_ref = cos(2*pi*f_ref*t0); s_sin = sin(2*pi*f*t0); s_cos = cos(2*pi*f*t0); %% Measurement signal s1 a1 = 1000; t1_1 = (1/fs):(1/fs):0.002; t1_2 = (1/fs):(1/fs):0.00153; t1_3 = (1/fs):(1/fs):0.00294; t1_4 = (1/fs):(1/fs):0.00153; t1_5 = (1/fs):(1/fs):0.002; d1_1 = t1_1*0; d1_2 = d1_1(length(d1_1)) + 0.5*a1*t1_2.*t1_2; d1_3 = d1_2(length(d1_2)) + t1_3*1.53; d1_4 = d1_3(length(d1_3)) + t1_4.*1.53 - 0.5*a1*t1_4.*t1_4; d1_5 = d1_4(length(d1_4)) + t1_5*0; d1 = [d1_1, d1_2, d1_3, d1_4, d1_5]; figure; plot(t0, d1);grid on;hold on; xlabel('t (s)');ylabel('d (m)'); title('The theoretical displacement of s1'); % d1 = v_max*t0; %d1 = 0.5*0.5*t0.*t0; theta1 = (2*pi*4/lambda)*d1; s1 = cos(2*pi*f_ref*t0 + theta1); % figure; % plot(t0, d1);grid on;hold on; % xlabel('t (s)');ylabel('d1 (m)'); % title('The theoretical value of the calculation result from s1'); %% Measurement signal s2 % d2 = (v_max/2)*t0; f2 = 1000; d2 = 0.0002*sin(2*pi*f2*t0); figure; plot(t0, d2);grid on;hold on; xlabel('t (s)');ylabel('d (m)'); title('The theoretical displacement of s2'); theta2 = (2*pi*4/lambda)*d2; s2 = cos(2*pi*f_ref*t0 + theta2); % figure; % plot(t0, d2);grid on;hold on; % xlabel('t (s)');ylabel('d2 (m)'); % title('The theoretical value of the calculation result from s2'); %% Measurement signal s3 t3_1 = (1/fs):(1/fs):0.002; d3_1 = t3_1*0; d3_2 = t3_1*0+lambda/4096/4; d3_3 = t3_1*0+2*lambda/4096/4; d3_4 = t3_1*0+3*lambda/4096/4; d3_5 = t3_1*0+4*lambda/4096/4; d3 = [d3_1, d3_2, d3_3, d3_4, d3_5]; figure; plot(t0, d3);grid on;hold on; xlabel('t (s)');ylabel('d (m)'); title('The theoretical displacement of s3'); theta3 = (2*pi*4/lambda)*d3; s3 = cos(2*pi*f_ref*t0 + theta3); % %% Add some noise % level_n = 1.5e-3; % s_ref = s_ref + (rand(1, length(t0))-0.5)*2*level_n; % s1 = s1 + (rand(1, length(t0))-0.5)*2*level_n; % s2 = s2 + (rand(1, length(t0))-0.5)*2*level_n; % s3 = s3 + (rand(1, length(t0))-0.5)*2*level_n; %% Test s1 phase0 = DFT_Cal(s_ref, s_sin, s_cos); phase1 = DFT_Cal(s1, s_sin, s_cos); phase_1 = phase1 - phase0; %phase_1 = phase1; d1_r = phase_1 / (2*pi*4/lambda); figure; plot(t0, d1_r);grid on;hold on; xlabel('t (s)');ylabel('d1 (m)'); title('The calculated displacement s1'); %Error analysis error1 = d1 - d1_r; error1 = error1(N+1:length(t0)-N); error1 = error1 - mean(error1); error_4096_std = zeros(1, length(error1)); error_4096_std_up = error_4096_std + (2*pi/4096)/(2*pi*4/lambda); error_4096_std_down = error_4096_std - (2*pi/4096)/(2*pi*4/lambda); figure; plot(t0(N+1:length(t0)-N), error1);grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_up,'r');grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_down,'r');grid on;hold on; xlabel('t (s)');ylabel('error1 (m)'); title('The relative error of s1'); % frequency-domain analysis % cas_calc(error1, fs); %% Test s2 phase0 = DFT_Cal(s_ref, s_sin, s_cos); phase2 = DFT_Cal(s2, s_sin, s_cos); phase_2=phase2-phase0; d2_r = phase_2 / (2*pi*4/lambda); d2r=tsmovavg(d2_r, 's', 20) ; figure; plot(t0, d2_r);grid on;hold on; axis([0 0.01 -0.0002 0.0002 ]); xlabel('t (s)');ylabel('d2 (m)'); title('The calculated displacement s2'); % Error analysis error2 = d2 - d2_r; error2 = error2(N+1:length(t0)-N); error2 = error2 - mean(error2); % % error_4096_std = zeros(1, length(error1)); % error_4096_std_up = error_4096_std + (2*pi/4096)/(2*pi*4/lambda); % error_4096_std_down = error_4096_std - (2*pi/4096)/(2*pi*4/lambda); figure; plot(t0(N+1:length(t0)-N), error2);grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_up,'r');grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_down,'r');grid on;hold on; xlabel('t (s)');ylabel('error2 (m)'); title('The relative error of s2'); %% Test s3 phase0 = DFT_Cal(s_ref, s_sin, s_cos); phase3 = DFT_Cal(s3, s_sin, s_cos); phase_3 =phase3- phase0; d3_r = phase_3 / (2*pi*4/lambda); %d3r=tsmovavg(d3_r, 's', 20) ; figure; plot(t0(N:length(t0)-N), d3_r(N:length(t0)-N));grid on;hold on; %plot(t0(N:length(t0)-N), d3r(N:length(t0)-N));hold on; xlabel('t (s)');ylabel('d3 (m)'); title('The calculated displacement s3'); % Error analysis error3 = d2 - d2_r; error3 = error3(N+1:length(t0)-N); error3 = error3 - mean(error3); % % error_4096_std = zeros(1, length(error1)); % error_4096_std_up = error_4096_std + (2*pi/4096)/(2*pi*4/lambda); % error_4096_std_down = error_4096_std - (2*pi/4096)/(2*pi*4/lambda); figure; plot(t0(N+1:length(t0)-N), error3);grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_up,'r');grid on;hold on; plot(t0(N+1:length(t0)-N), error_4096_std_down,'r');grid on;hold on; xlabel('t (s)');ylabel('error3 (m)'); title('The relative error of s3'); % frequency-domain analysis % cas_calc(error2, fs);