330 
Random signals, second-order proba- 
bility density function, 251 
spectral density function, 254-255 
Regulator systems, 192 
Ripple, 6, 18, 199-219 
approximation of, in feedback sys- 
tems, 202 
using infinite summation, 199-202 
determination of, by use, of advanced 
z transforms, 212-217 
of multirate sampling technique, 
202-206 
of partial fraction summation, 
206-212 
Ripple-free sampled-data systems, 
169-173 
design of, rules for, 170 
using state variable feedback, 173- 
178 
Root locus for sampled-data systems, 
105-110 
Routh-Hurwitz stability criterion for 
sampled-data systems, 98-100 
Sample sequence, sum of squares of, 
78-79 
Sampled-data processing unit, 92 
(See also Digital controller) 
Sampled-data system design, equiva- 
lent digital controller, 173-178 
minimal prototype, 148-153 
minimizing integrated square error, 
178-181 
with plant saturation, 181-186 
ripple-free, 169-173 
by use, of continuous networks, 
117-136 
of digital controllers, 145-173, 
186-192 
(See also Digital controller) 
of pulsed networks, 136-143 
of root locus, 138-139 
Sampled-data systems, 4-5, 86-116, 
130-133, 153-155, 181-186, 192- 
195, 320 
SAMPLED-DATA CONTROL SYSTEMS 
Sampled-data systems, approximation 
by use of most important side- 
bands, 130-133 
behavior between sampling instants 
(see Ripple) 
closed-loop, 155-163 
compensation of (see Compensation 
of sampled systems) 
digital controllers for (see Digital 
controller) 
dominant poles of, 109-110 
effect of disturbances on, 192-195 
feedback, 5-7, 90-105 
frequency response of (see Frequency 
response of sampled-data sys- 
tems) 
hidden oscillations in, 93-94, 136, 
199, 217-218 
minimization of integrated square 
error in, 179-181 
multirate (see Multirate sampled- 
data systems) 
open-loop, 4-5 
compensation of, 153-155 
random signals in, 261—267 
(See also Random signals) 
root locus, 105-110 
saturation in, 181-186 
stability of (see Stability of sampled- 
data systems) 
table of basic relationships, 320 
Sampled-data theory, miscellaneous 
applications of, 10-11, 282-312 
Sampled elements in cascade, 86-90 
Sampled random signals, 255-258 
optimum linear filtering of, 267-280 
comparison to zero-order data 
hold, 278-280 
feedback implementation, 277-278 
mean-square error, 272 
transfer function of optimum filter, 
272 
(See also Random signals) 
Sampling, approximation by most im- 
portant sidebands, 130-133 
double-rate, 203-206 
