Page 58 - Understanding Automotive Electronics

2735 | CH 2 Page 45 Tuesday, March 10, 1998 10:55 AM

THE SYSTEMS APPROACH TO CONTROL AND INSTRUMENTATION 2

The response that is often optimum for many applications is called critical
damping D :
c
D = M K
u
c
Critical damping gives the most uniform response for the greatest range of
frequencies. This situation (which is normally the most desirable) is depicted by
the solid curve in Figure 2.11.
Step Response
The step response char- The performance of a system is also represented by its time response which
acterizes the perfor- is closely related to its frequency response. Perhaps the most meaningful method
mance of a system. of assessing the time response of a system is to examine its response to an input
step. Figure 2.12 is a graph of a step input to the example system as well as the

Figure 2.12
Step Response of a
System

FPO

UNDERSTANDING AUTOMOTIVE ELECTRONICS 45