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Lecture 23 – Freq. Domain Compensator Design. Review:. Review (cont.). Lead Compensator Design in Freq. Domain. What’s wrong with using Gc(s) = K to meet gain and phase margin specs? Form of the Lead Compensator:. Lead Compensator Design in Freq. Domain. Let’s look at a Bode Plot of.
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Lecture 23 – Freq. Domain Compensator Design • Review: EE571
Review (cont.) EE571
Lead Compensator Design in Freq. Domain • What’s wrong with using Gc(s) = K to meet gain and phase margin specs? • Form of the Lead Compensator: EE571
Lead Compensator Design in Freq. Domain • Let’s look at a Bode Plot of EE571
Lead Compensator Design in Freq. Domain • Parameters which need to be designed: • Procedure: • Pick Kc(s) to meet ess specs • Lump Kc(s) in with G(s) and make Bode Plot of KcG(s) • Measure gain and phase margins • Choose m such that: • Find where • Find frequency cgnew where • Solve for T • Go back EE571
Lead Compensation Example • G(s) = 4/(s+2) • Specs: ess|ramp = 1/40 • gm > 10 dB • pm 50o EE571
Lead Compensation Example • Matlab Code: EE571
Lead Compensator Design in Freq. Domain • Form of Lag Compensator: • How the heck can we insert a lag compensator and improve stability?????? • Idea: • Parameters which need to be designed: EE571
Lag Compensator Design in Freq. Domain • Parameters which need to be designed: • Procedure: • Pick Kc(s) to meet ess specs • Lump Kc(s) in with G(s) and make Bode Plot of KcG(s) • Measure gain and phase margins • Find frequency cgnew where • Set where • Set 1/T • Go Back EE571
Lag Compensation Example • G(s) = 4/(s+2) • Specs: ess|ramp = 1/40 • gm > 10 dB • pm 50o EE571
Lag Compensation Example • Matlab Code: EE571
Lag Compensation Example EE571
Differences in the Lead and Lag Design • Classic 2nd Order System: • Relationship Between Bandwidth and Settling Time: EE571