help needed PID control calculations(BRUSHLESS DC MOTOR CONTROL)

Hi ALL,

I am mohd sulaiman. I am working on Brushless dc Motor position control.In my application we are controlling the motor using the dsp processor from TEXAS i.e TMS320LF2407A. my design have been completed now i have startedd to write the code for the application. I have doubt regarding the implementatation of the PID and PI control in software and how do we determine the Respective constants of the PID or PI controller. could any one explain on what parameters of the motor they are dependent and how do we determine them.

Thanking you in Advance, With Regards Mohd sulaiman

Reply to
Sulaiman mohd
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You're familiar with analog control loop theory ? Open loop response and closed loop response of the system ? If your sampling frequency is far above the bandwidth you can proceed if it was analog, else you have to pull it over to the digital domain by the means of the Z-tranform.

Rene

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Reply to
Rene Tschaggelar

look in microchip's site, they have an application note. It goes into all the theory.

Reply to
CBarn24050

Z-transform is the discrete version of the lapplace transform. If your sampling frequency is too low, you are cutting off the high freqency responses. That's true for both digital and analog.

Let me try some simpler terms. Basically, any analog wave form can be modeled in a sequence of fundamental frequencies. If you pick n of the important ones, you can simulate the characteristic of the system with N differential equations, or a Nth order matrix. Then your system is in the form of Y(t) = M(t)X(t) + A(t), where M(t) is NxN and A(t) is Nx1 You just need a do some matrix calcuations (computer can do that very well).

If you need additional details, please email me (epl). I don't think other people want to bother with these details.

Reply to
Edward Lee epl

On 5 May 2004 22:17:07 -0700, snipped-for-privacy@hotmail.com (Sulaiman mohd) wrote in comp.arch.embedded:

Have you already looked at the applications notes for motor control available from the web page

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?

This one has source code available:

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Jack Klein
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Jack Klein

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