# How to design a 'phase-lead compensator'?

Discussion in 'Homework Help' started by woodmark75, Dec 14, 2014.

Dec 11, 2014
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2. ### t_n_k AAC Fanatic!

Mar 6, 2009
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Assume a second order response approximation of the actual response.
The required PO then leads to the damping factor $\zeta$.
The settling time needs to be stated as being within a certain percentage (5%,2%, ??) of the final value. This leads to a value of $\omega_n$ given the required damping factor $\zeta$.
Knowing damping factor and $\omega_n$ then allows you to place a target dominant complex pole pair on the root locus plane. Presumably the uncompensated root locus doesn't include the target pole pair. Lead compensation design then requires you to "force" the root locus to intersect the target dominant pole pair.
There is a wealth of guidance on the Web on how to do this. You should show some effort on your part to indicate you are at least familiar with the process.

3. ### woodmark75 Thread Starter Member

Dec 11, 2014
36
0
Yes I should have said that the Ts is +/- 5%.

4. ### t_n_k AAC Fanatic!

Mar 6, 2009
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Other than the specifications given, one might also expect to have a steady state error specification. Could be important in the aircraft control.