Standard Test Signals

What is Signal?

A signal is a physical quantity or a function of one or more independent variables such as Time and Space. It contains or conveys some information. There are many signals in this world which change with respect to Time and Space. Standard test signals are the signals which are used to estimate the performance and characteristics of the system by analyzing the responses of these signals. These signals are applied one by one as input to the system to determine different responses of the system in different cases and then we estimate different characteristics of the system such as Stability, Linearity, Transient response, and Frequency response by analyzing different responses or we can say outputs of the system. In terms of Mathematical representation of signals, these signals are used to represent complex signals....

Standard Test Signals

Standard test signals are the signals which are used to check the control systems performance using time response of the output. There are various Standard test signals which are listed below, we will discuss one by one about these signals With their mathematical expressions and graphical representation....

Step Signal

A Step signal is one of the standard test signal. It is also known as Heaviside’s function or Heaviside’s Step signal. The magnitude of step signal is constant. A Step signal exists only for positive values and zero for negative values. It is denoted by u(t), mathematically u(t) will be constant for t>0 ( i.e., for positive values) and will be zero for t<0 (i.e., for negative values). It represents sudden change in the reference input. It is used to analyze system response to sudden changes in the reference input. It is defined by its magnitude....

Ramp Signal

A Ramp signal is one of the standard test signal. It is an increasing function which increases linearly with Time. A Ramp signal exists only for positive values and zero for negative values. It is denoted by r(t), mathematically r(t) will be ‘ t ‘ for t>=0 ( i.e., for positive values of t ) and will be zero for t<0 (i.e., negative values of t ). Ramp signal is used to analyze system response to linearly changing inputs. It is also known as velocity type input. Ramp input is defined by its slope....

Impulse Signal

An Impulse signal is one of the standard test signal. It is also known as Dirac delta function. An Impulse signal exists only at zero. The magnitude of an Impulse signal is infinity. It is denoted by δ(t), mathematically δ(t) will be infinity at t = 0 and zero for t ≠ 0. An impulse signal is an infinitesimally narrow pulse with unit area and infinite amplitude. It is used to analyze system response to Impulse – like inputs. It gives overall system response. Continuous Impulse signal is defined by its magnitude whereas Discrete Impulse signal is defined by its Amplitude....

Parabolic Signal

A Parabolic signal is one of the standard test signal. Parabolic signal is the signal whose magnitude varies as square of time. It is represented by p(t), mathematically p(t) will be t2/2 for t>=0 ( i.e. for positive values) and will be zero for t<0 ( i.e. for negative value ). It is also called acceleration type input. It is used to analyze system response to Non linear inputs....

Relationship Between Signals

Given below are some Relationship between signals :...

Standard Test Signals – FAQs

What are the real-life examples of unit step signals?...