Digital Control Systems [MEE 4003] - Kckong.info

1.1. PROBLEM DEFINITION 5
dimension (across a scan line) and two discrete dimensions (frame and line).
1.1.5 Continuous-time and discrete-time signals
If the quantities are defined only on a discrete set of times, we call it a discrete-time signal.
The discrete-time signal can be indexed by an integer that represents the sequence of each
data point.
On the other hand, a continuous-time real signal is any real-valued function that is
defined for all timetin an interval.
[Example 1-3] An example of the continuous-time and discrete-time signals is shown
in Fig. 1.3. In general, the discrete-time signal is a sampled version of its corresponding
continuous-time signal.
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Figure 1.3: Continuous-time and discrete-time domain signals.
(a): a continuous-time signal, (b): a discrete-time signal
1.1.6 Digital control
Digital control is a branch of control theory that uses digital computers to act as system
controllers. Depending on the requirements, a digital control system can take the form
of a microcontroller (costs less than 10,000 KRW) to a digital signal processor (DSP,
costs more than 10,000,000 KRW). Since a digital computer has finite precision (i.e.,
Digital Control Systems, Sogang University
Kyoungchul Kong