-28] STATIC AND DYNAMIC CONTROL LOOP ERRORS 



3. Minimum phase equation : 



— — ^ — ' = — (differentiate Equation 8-37) 



Combining Equations 8-37 and 8-38 



2(c02 — CO]) 2(a)2 — OJl) 



0.69 



and 



0.69 



Wm 0.64cOc 



2co,(a;2/co, - 1) 2a)i(5.49) 



447 

 (8-38) 



(8-39) 

 (8-40) 



0.64a;. (0.64) (61. 6) 



from which coi = 2.48 and co2 = 16.1 

 O^r. = 39.4 



CO. = 61.6 



C0.3 = 114. 



These are the search loop corner frequencies, bandwidth, and maximum 

 phase frequency in radians per second. A log magnitude phase diagram or 



Odb 



400 



(ili-) 



s{m*') (ii4+' 



25.0 

 39.4 



1.6 wc=61.6 

 



Fig. 8-33 Nichols Chart of Search Loop. 



