The mode of control is the way in which a control system makes corrections relative to an error that exists between the setpoint of a controlled variable and its actual value.
We have a number of ways (i.e. control modes) … Read more
Tag: controllers
The Performance Limits for PID Controllers
PID Controllers can be applied successfully to most control problems in process control, electrical drive systems and servo mechanisms due to the fact that most of these processes have a dynamic behaviour that can be adequately approximated by a second-order … Read more
What is a Discontinuous Controller?
This is a controller with only 2 switching states, that is, the output signal is switched ON and OFF depending on whether the process variable goes below or above a preset limit or setpoint.
An example of a discontinuous controller … Read more
Analog vs Digital Controllers
Analog signals pass continuously through a full range of values for example a measuring device converts the process variable (PV), say temperature, into a signal corresponding to this temperature. Each temperature value corresponds to a value of the electrical signal. … Read more
Position Control System using a Microprocessor-Based Controller
Consider the following figure illustrating a position control system employing a microprocessor-based controller with parallel ports:
The system above has one output port and three input ports (each port has its own address). … Read more
Basic Steps to Consider in Designing a Control System
Typically a control system should be designed to work together with an already existing process. The control design problem can be stated at local, supervisory or even plant-wide level.
If we consider the local level, the typical steps in designing … Read more
Fuzzy Controller and its Industrial Applications
Fuzzy logic is a human model, potentially applicable to a wide range of processes and tasks that require human instinct and experience. In computer, truth-values are either 1 or 0, which corresponds to true/false duality. In fuzzy logic, truth is … Read more
Basic Elements of a Digital Controller for a Steam-Turbine Driven Generator
The block diagram below illustrates the basic elements of a minicomputer system for speed and voltage control as well as data acquisition of a steam-turbine driven generator unit.
Typical output variables … Read more
How Controllers are used in Industrial Automation Systems
In many process control systems, microprocessor based programmable logic controllers are used for decision making due to the sophistication of the system and the large number of process variables involved.
The PLC can be configured to receive a small number … Read more
How to Tune the PID Controller
Before we discuss how to tune the PID controller, let’s look at some basic facts about PID Controller.
Basic Facts about PID Controller
Many control systems use a combinational of three types of control i.e. Proportional + Integral + Derivative … Read more