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DIGITAL SIGNAL 8

PROCESSING (DSP)

All humans practice digital signal processing (DSP) daily. This may come as a sur-
prise, but it’s true. Further, very few people know the simple theory that they actually
practice each day by instinct alone. In this chapter, we’ll discuss the theory and relate
it to real-life examples.
First, let’s quickly review how DSP functions. Most of the real world is analog, not
digital. The robot will need to look at signals of all sorts. These signals have to be acces-
sible to the control computer so the proper processing can occur.
Figure 8-1 shows one way this can be done. An analog-to-digital (A/D) converter
digitizes the analog input signals. The digital representations of the signals then go into
the computer where they are processed as needed for the application. The computer can
then output digital results, some of which can drive a digital-to-analog (D/A) converter,
which generates analog signals for output. Each element in this chain of electronics
serves to modify the information from the original signals in various ways. We’ll dis-
cuss the characteristics of each block in the figure later in the chapter, but for now, just
realize that the computer cannot see the analog signals at all times. It can only sample

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