Calculating phase delay for one signal to have the same zero crossings

I need to fix the phase delay in the triangle signal to make sure all signals have the same zero crossings. I keep getting error messages (either not enough input arguments or an error within a specific signal that only shows up if I try to calculate). Is there a recommended formula to calculate and fix the phase delay?

% This script will generate a figure that plots a pulse waveform as a function of time.

% Set the signal parameters

Frequency_Hz = 100;

Amplitude = 1;

Phase_rad = 0;

DutyCycle = 90; % the percentage (0-100%) of the cycle the pulse train is "high" (positive)

Duration_sec = 0.03;

SamplingRate_Hz=20000;

% Generate the signal and corresponding time vector

[signal, time_sec] = pulse_542(Amplitude, Frequency_Hz, Phase_rad, DutyCycle, Duration_sec, SamplingRate_Hz);

% Create a plot showing the signal as a function of time

figure(1) % Creates figure number 1

hold on

plot(time_sec, signal, 'r-') % Plot the signal as a red solid line

ylim([-1.2 1.2]*Amplitude) % Allow better visualization of the pulse train

% This script will generate a figure that plots a triangle waveform as a function of time.

% Set the signal parameters

Frequency_Hz = 100;

Amplitude = 1;

Phase_rad = 0;

Duration_sec = 0.03;

SamplingRate_Hz=20000;

% Generate the signal and corresponding time vector

[signal, time_sec] = triangle_542(Amplitude, Frequency_Hz, Phase_rad, Duration_sec, SamplingRate_Hz);

% Create a plot showing the signal as a function of time

plot(time_sec, signal, 'g:') % Plot the signal as a dotted green line

% This script will generate a figure that plots a tone as a function of time.

% Set the tone parameters

Frequency_Hz = 100;

Amplitude = 1;

Phase_rad = 0;

Duration_sec = 0.03;

SamplingFreq_Hz=20000;

% Generate the tone and corresponding time vector

[tone_signal, tone_time_sec] = tone_542(Amplitude, Frequency_Hz, Phase_rad, Duration_sec, SamplingFreq_Hz);

tone_signal=tone_signal+1;

% Create a plot showing the tone as a function of time

plot(tone_time_sec, tone_signal, 'b--') % Plot the signal as a dashed blue line

hold off

title('Signals as a function of time') % Adds a title to the plot

ylabel('Signals') % Labels the y-axis

xlabel('Time (sec)') % Labels the x-axis

print -dtiff test

Answer 1

[Mathieu NOE]

hello

unfortunately you did not provide (attach) the functions you are sing to generate the waveforms

nevertheless, see below a code to show how to measure time lag between signals, that you can afterwards use to sync your signals

the result obtained here is 0.2 rad , which is what I defined in the signals at the beginning

all the best

x = 0:0.1:30;
y1 = sin(x+0.25).*exp(-x/10); % reference signal 
y2 = 0.75*sin(x+0.45).*exp(-x/10);  % signal shifted by 0.2 rad

figure(1),
plot(x,y1,'r',x,y2,'b');

% find crossing points at y threshold = 0
threshold = 0;
[xc1] = find_zc(x,y1,threshold);
[xc2] = find_zc(x,y2,threshold);

% phase shift  = x distance divided by period and multiplied by 2pi
p1 = mean(diff(xc1)); % mean period of signal 1
p2 = mean(diff(xc2)); % mean period of signal 2

phase_shift = mean(xc1-xc2)/p1*2*pi % is the value used in the data generation 

phase_shift = 0.2000

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [Zx] = find_zc(x,y,threshold)
% positive slope "zero" crossing detection, using linear interpolation
y = y - threshold;
zci = @(data) find(diff(sign(data))>0);  %define function: returns indices of +ZCs
ix=zci(y);                      %find indices of + zero crossings of x
ZeroX = @(x0,y0,x1,y1) x0 - (y0.*(x0 - x1))./(y0 - y1); % Interpolated x value for Zero-Crossing 
Zx = ZeroX(x(ix),y(ix),x(ix+1),y(ix+1));
end

[Mathieu NOE]

hello again

do you mind accepting my answer (if it has fullfiled your expectations ) ? tx