## Proportional (P), Integral (I), Derivative (D) Controllers Usage Conditions

1. When does the Proportional (P) Controller is used? Answer. Proportional (P) Controller is used during the following conditions: Load Changes are small Offset (error exist due to difference between steady state value and desired value) can be tolerated. The process reaction rate is such as to permit a narrow proportional band. Since this reduces … Read more

## Distributed Control System (DCS) in Power Plant

Usage of Single Computer for control of all the process variables of a plant would result in the loss of control activities in the plant if a failure occurs in the master single computer. Also, the time required for accessing large data, processing the received data and controlling of the entire plant by single computer … Read more

## Extended Kalman Filter – Algorithm & Applications

In the previous article, we had learned about Kalman filter. As Kalman filter assumes linear system but finds greatest applications in non-linear systems. Kalman filter assumes an approximate solution, describe the deviations from the reference by linear equations. Kalman filter has issues of divergence also. When the error covariance matrix Pk computed by the Kalman filter … Read more

## Kalman Filter | Algorithm & Applications

The Kalman filter is a recursive state space model based estimation algorithm. In other words, it is an optimal recursive data processing algorithm. Kalman filter is also called as the Predictor-Corrector algorithm. This filter is named after Rudolph E. Kalman, who in 1960 published his famous paper describing a recursive solution to the discrete data … Read more

## Servomechanism | Servomotor & Applications

Servomechanism It is a feedback control system in which a controlled variable or the output is a mechanical position or its time derivatives like velocity and acceleration. Servomotors have two main classifications based on servomechanism i.e. 1. DC Servomotors Armature controlled DC motor Field Controlled DC motor 2. AC Servomotors 1. DC Servomotors DC ServoMotor … Read more

## Signal Flow Graph

In case of block diagram reduction diagram, there is no standard procedure for reducing the block diagram to evaluate its transfer function. Also, the block diagram reduction technique is tedious and is difficult to choose the rules to be applied for reduction. In order to avoid such problems, the block diagram is converted to signal … Read more

## State Space Representation of a System

The control system analysis fails for multiple-input multiple-output (MIMO) systems and the systems initially not at rest by using transfer function approach. The use of the state-space approach for the analysis of control systems enables to overcome the shortcomings of the transfer function approach. State The state of a dynamic system is the smallest state of variables … Read more

## Mechanical Electrical Analogy

Mechanical Electrical Analogy The concept of an analogous system is very useful in practice. Since one type of system may be easier to handle experimentally than other. A given electrical system consisting of resistance, inductance and capacitance may be analogous to the mechanical system consisting of a suitable combination of dashpot, mass, and spring. Analogous System … Read more

## Performance Indices in Control System- ISE,IAE,ITSE,ITAE

When we design a control system for a physical process, one or more parameters are to be selected to give the best performance. For this purpose, a measure known as Performance Indices is used. The usual criteria for performance index are given using 4 expressions which are the function of an error signal. 1. Integral Square … Read more