how to check weather the values are constant or fluctuating over a period of time and give a output in one or zeros in a simulink model

in the above image the values are changing between 1 and 0 this is because vales are not in an increasing order

in the above image the values are constant 1 ( for 50 seconds)

i want to develop a model that can read the values till the 50 seconds and return a value of 1 if the values are flautuating like image 1 and 0 if the values remain constant (1) for fifty seconds

Answer 1

[Manish]

Hi abhijeet.

I understand that you want to check whether values are constant or fluctuating during the first 50 seconds and output a 1 or 0 accordingly.

To achive this follow the below steps:

• Add the 'MATLAB function' block to the Simulink model.
• Implement the code in the 'MATLAB Function' block to determine if values are constant or fluctuating over 50 seconds and output the result. (See the sample code below.)
• Connect the input signal to the 'MATLAB Function' block.
• Add a 'Display' block to the model and connect it to the output of the 'MATLAB Function' block to visualize the result.

Here is sample code for the step 2:

function y = checkFluctuation(u)
    persistent valuesArray index 
    % Initialize persistent variables
    if isempty(valuesArray)
        valuesArray = -1 * ones(1, 50);  % Initialize with -1
        index = 1;
    end
    if index <= 50
        valuesArray(index) = u;
        index = index + 1;
    end
    % Check if the array is filled
    if index > 50
        % Check if all values are 1
        if all(valuesArray == 1)
            y = 0;
        % Check for alternating pattern 101010...
        elseif isequal(valuesArray, repmat([1 0], 1, 25))
            y = 1;
        else
            y = -1;
        end
    else
        y = -1;
    end
end

Refer the below links for better understanding:

• https://www.mathworks.com/help/matlab/ref/persistent.html
• https://www.mathworks.com/help/simulink/slref/matlabfunction.html

Hope it helps!