my project is pi controller. i finished p controller but i don't know how to do the integral equation using assembly language.

can anyone give the algorithm for simple integral equation.

thanks for timely help.

 

In a PI (or PID) control loop, the integral part is computed by:

Ki*T*e(k)

where Ki is your constant, T is the control loop sampling period, and e(k) is the current error between your desired and actual output.

e(k) = s(k) - m(k)

where s(k) is the set value and p(k) is the measured value

 

thanks for your reply

i have some doubts on the above equation kindly clarify my doubts

can u give some examples for integral constant

units of T is in sec or minutes

For example

ki is 10

T is 5sec

e(k)=20 (s(k)-m(k)),s(k)=40 m(k)=20

then
output y=10*5*20

is it correct, unit of output is in terms of sec or minutes

 

Well, I dont know what kind of system you are controlling (perhaps you should mention it), but a sampling period of minutes seems very long. I could *maybe* understand seconds for a hot-plate or something. For motor control and positioning, I was thinking along the lines of milliseconds or even useconds.

The value of ki will depend much on your system, but some of mine have ki around 0.1, 0.2, 0.4, etc.