how to calculate rise time fall time for this graph in generalized manner

I need to calculate rise time and fall time of the multiple pulses in the graph in automated way. the only toolbox i have is image processing and the basic tools.

So, i cannot use directly the rise time and fall time commands(as they are contained in signal processing toolbox).

Is there any way, hint for solving this problem.

[SHANTANU KSHIRSAGAR]

i had written a code as follows :

but due to unavailability of signal processing toolbox not able to perform the rise time and falltime commands.

can we do it in generalised way, without using any toolbox as such.

filetype='*.xlsx';
f=fullfile(folder,filetype);
d=dir(f); 
    
for k=1:numel(d)     
MATRIX = xlsread(fullfile(folder,d(k).name));
rise_time=riserisetime(MATRIX(:,2)); 
fall_time=falltime(MATRIX(:,2));
filename1 = 'test1.xlsx';
filename2 = 'test2.xlsx';
writematrix(rise_time,filename1,'sheet',k);
writematrix(fall_time,filename2,'sheet',k);
end

[darova]

I highlighted points in red. Is it correct?

[SHANTANU KSHIRSAGAR]

I want to calculate rise time and fall time for each pulse. I would like to ask what is the significance of the the points which you have marked. Do you mean to seperate pulses through those points? But you do so we would miss some data between points marked . Can we make it taking all data into consideration.

[darova]

I selected points of rise and fall. I just want to know if i understand correctly you question

[SHANTANU KSHIRSAGAR]

There are ripples in the curve we also need to consider them , need to take 10%to 75% as rise time and 100% to 20% as fall time .

[darova]

Can you show it on the image?

[SHANTANU KSHIRSAGAR]

here due to ripples the there is deviation from the upper zero level(consider the middle value) and also same ata the lower zero level . after calculating the exact zero level from the ripples , we need to find out the 10%,75% values for the rise time. and 100% and 20% on falling edge for fall time. These values will keep changing slightly as each of the upper and lower zero levels in the ripples will change .

[darova]

Can you attach the data?

[SHANTANU KSHIRSAGAR]

I have attached a excel worksheet which contains the required data.

Answer 1

[darova]

I want to show you how succesfull i am

please see attached script

[SHANTANU KSHIRSAGAR]

This is really close to the solution. Can we find the rise time and fall time through the obtained graph.

1. I wanted to inquire about the use of tand operator that you have made(I think it is related to tan of an angle).

2. can the ripple be calculate for the upper part of each pulse.

[SHANTANU KSHIRSAGAR]

From the obtained plot we can see that multiple points are obtained for whatever, say 10% or 75% .(when i have reduced the step size to 50).

Why have we taken the 100 as the sampling value (Here, ii = 1:100:length(x);).

we need to find the precise value for the 10% and 75% because those will be needed to find the rise time and fall time. I have attached the enlarged view of the obtained graph.

[SHANTANU KSHIRSAGAR]

also the logical operator which has been used is producing tentetive outputs and not the correct one's as per my perception.

[SHANTANU KSHIRSAGAR]

Thank you for the answer ,

• define the use of < tand (89.9)
• use of logical operator (values obtained are only in the form of 1's and 0's.)

in the attached script by you.