Errors in control systems can be attributed to many factors. Changes in the reference input will cause unavoidable errors during transient periods and may cause steady state error also. Imperfections in the system components such as static friction, backlash (a sudden strong response or reaction), amplifier drift as well as aging or deterioration will cause errors at steady state.
6.2 TYPES OF INPUT SIGNALS
In analysing or designing a particular control system, we must have a basis of comparison of performance of various control systems. This basis may be set by specifying particular test input signals and by comparing the responses of various systems to these input signals. Usually the input signals to control ...