How to adjust value from matlab-mfile and feedback in simulink

I am having a model in simulink uploaded at:

<http://www.freeimagehosting.net/79moh. >

In the first iteration the model should take value from matlab mfile and calculate error for Pid as e=r-i where 'i' is the value taken from matlab mfile but after that it should take feedback and calculate the error as e=r-y where 'y' is the value of feedback from space state. How can I do that in simulink. Any guidance?

Answer 1

[Muruganandham Subramanian]

step1:Initialize all i/p data in m-file & variable 'i'

step2: use 'sim()' command to run your model

step3: store the value of 'y' in baseworkspace by 'To workspace' block from model

step4:calculation

[Beenish Mazhar]

Sir I have tried using these commands even then the value of simin is not updated I have attached the code and the updated block diagram is uploaded at< http://www.freeimagehosting.net/aauvl>. Please suggest me further changes.

clc 
clear all
close all
Tstop=10;
simin=[0 0]
options =simset('SrcWorkspace','current');
sim('pidtry',Tstop,options)
simin=simout3

[Muruganandham Subramanian]

Insteadof using 'simin', you can do this by creating closed(feedback) loop by output signal(simout) followed by 'unit delay(1/z)' then to subtraction block.Initial condition for delay block is '0'.

[Beenish Mazhar]

sir I guess this is what you are saying which I have uploaded at http://www.freeimagehosting.net/na4ts. But sir then where shall I give the initial value from m-file. Kindly guide me.

[Muruganandham Subramanian]

check this:

<<C---Users--Admin--Desktop--New-nbsp-picture.jpg>>

[Beenish Mazhar]

Sir the link or code in your comment is not given.

[Muruganandham Subramanian]

constant->'(+-)' block->(-)simin(Insteadof this) %simin is not needed

From output(i.e.simout3)--> use 'unit delay'(1/z)block from simulink library, initial codition as '0'(i.e.zero) in delay block and then connect to (-)sign of add block

[Beenish Mazhar]

Thank you sir for your reply.Sir in the link given above I have done the same work and I have used the simin command because it is not necessary that initial value taken from mfile is zero, it may vary i.e simin initial value could be 2 or 5 etc.Kindly now tell me how to resolve the issue

[Muruganandham Subramanian]

Initial condition in unit delay is user specified. so you can give any value like 0 or 2 or 5 or etc...