Definition: The actuators that are designed to operate on compressible fluid generally air, is known as Pneumatic Actuator. The Pneumatic actuators use the pressurized air as input and change it into mechanical motion. More specifically, pneumatic actuators are devices that change the pressure obtained by compressing the air into mechanical energy. Introduction We know that actuators are the devices employed in the control system that acts on the control signal received from the controller … [Read more...] about Pneumatic Actuator

# Control Systems

## Hydraulic Actuator

Hydraulic Actuator is the type of actuator that utilizes the hydraulic pressure as input in order to provide excitation to the plant (controlled process) of the control system. The controller provides the control signal to the actuator that hydraulically applies the equivalent signal to the plant in order to have the desired output in controlled operations. The hydraulic systems possess an operating pressure range between 1 to 35 Mega Pascals. These are widely used in closed-loop control … [Read more...] about Hydraulic Actuator

## AC Servomotor

A type of servomotor that uses AC electrical input in order to produce mechanical output in the form of precise angular velocity is known as AC servo motor. AC servomotors are basically two-phase induction motors with certain exceptions in designing features. The output power achieved from ac servomotor ranges between some watt to a few hundred watts. While the operating frequency range is between 50 to 400 Hz. It provides closed-loop control to the feedback system as here the use of a … [Read more...] about AC Servomotor

## DC Servomotor

Definition: A type of servomotor that uses DC electrical input to generate mechanical output like velocity, acceleration or position is known as DC servomotor. It is somewhat similar to a normal DC motor. However, there exist some differences between a normal dc motor and dc servomotor. Basically, DC servomotors of all types are required to be excited individually. This leads to provide linear characteristics between torque and speed. Introduction We have already discussed in our previous … [Read more...] about DC Servomotor

## Servomotors

Servomotors are electrical devices used for converting electrical signal provided as input into a precise angular velocity. It is known as a servo system. Basically, a servo system is the one that generates some form of mechanical variable like velocity, acceleration or position as its output. A servomotor is designed to generate the mechanical equivalent of the applied electrical signal. It is known to be a low power motor that finds applications in servomechanisms or position control … [Read more...] about Servomotors

## Analogous Systems

Definition: Electrical and mechanical systems possess fixed analogy and there exist similarity between the equilibrium equations of the two. This allows forming such electrical systems whose behavioural characteristics are similar to the given mechanical system. Such systems are known as analogous systems. More specifically, it is called electrical analogous of mechanical system. Basically, two systems are analogous in nature when the conditions given below are fulfilled: There must … [Read more...] about Analogous Systems

## Mason’s Gain Formula

It is a technique used for finding the transfer function of a control system. Basically, a formula that determines the transfer function of a linear system by making use of the signal flow graph is known as Masonâ€™s Gain Formula. It shows its significance in determining the relationship between input and output. Introduction In the previous article, we have seen how a signal flow graph is constructed. We have already seen that a signal flow is a graph is generally formed by using the … [Read more...] about Mason’s Gain Formula

## Signal Flow Graph of Control System

A graphical method of representing the control system using the linear algebraic equations is known as the signal flow graph. It is abbreviated as SFG. This graph basically signifies how the signal flows in a system. The equation representing the system holds multiple variables that perform a crucial role in forming the graph. Basically, if we have the set of equations that describes the system then by using the variables of the equation, the signal flow graph is obtained. This graph helps … [Read more...] about Signal Flow Graph of Control System

## Routh-Hurwitz Stability Criterion

Routh-Hurwitz stability criterion is an analytical method used for the determination of stability of a linear time-invariant system. The basis of this criterion revolves around simply determining the location of poles of the characteristic equation in either left half or right half of s-plane despite solving the equation. We have already discussed, the stability of the control system in our previous article. It is considered an important parameter of the control system. The stability of a … [Read more...] about Routh-Hurwitz Stability Criterion

## Nyquist Stability Criterion

Nyquist criterion or Nyquist stability criterion is a graphical method which is utilized for finding the stability of a closed-loop control system i.e., the one with a feedback loop. This criterion serves as a crucial way for design and analysis purpose of the system with feedback. Thus, it finds major application in Electronics and Control System Engineering. The principle of Nyquist criterion was independently proposed by an electrical engineer of German origin, Felix Strecker in the year … [Read more...] about Nyquist Stability Criterion