Bilal ahmed ansari
- 1. BILAL AHMED ANSARI PROFESSOR REHAN ADIL B.S ELECTRONICS(5th SEMESTER) DATED:19/12/2012. TITTLE MODERN CONTROL SYSTEM ABSTRACT: In this research we describe a general process for designing a control system. A control system consisting of interconnected components is designed to achieve a desired purpose.To understand the purpose of a control system, it is useful to examine examples of control systems through the course of history.These early systems many of the same ideas of feedback that are in use today.Modern control engineering practice includes the use of control design strategies for improving manufacturing processes, the efficiency of energy use, advanced automobile control, including rapid transit, among others.We also discuss the notion of a design gap. The gap exists between the complex physical system under investigation and the model used in the control system synthesis. The iterative nature of design allows us to handle the design gap effectively while accomplishing necessary trade offs in complexity, performance, and cost in order to meet the design specifications. INTRODUCTION: This is written at the level of the senior engineering student and is intended to be used as a text for the first course in control systems. It presents a comprehensive treatment of the analysis and design of continuous-time control systems. It is assumed that the reader has had courses on introductory differential equations, introductory vector matrix analysis, introductory circuit analysis, and mechanics. Control engineering is based on the foundations of feedback theory and linear system analysis, and it generates the concepts of network theory and communication theory. Accordingly, control engineering is not limited to any engineering discipline but is applicable to aeronautical, chemical, mechanical, environmental, civil, and electrical engineering. 18th Century: James Watt’s centrifugal governor for the speed control of a steam engine. 1920s: Minorsky worked on automatic controllers for steering ships. 1930s: Nyquist developed a method for analyzing the stability of controlled systems 1940s; Frequency response methods made it possible to design linear closed loop control systems 1950s: Root-locus method due to Evans was fully developed 1960s: State space methods, optimal control, adaptive control and 1980s: Learning controls are begun to investigated and developed.
- 2. Present: And on-going research fields. Recent application of modern control theory includes such non engineering systems such as biological, biomedical, economic and socio-economic systems To understand the word control system, first we have to know the meaning of word system and then word control system can be clear. SYSTEM: A system is a combination or an arrangement of different physical components which act together as an entire unit to achieve certain objectives. CONTROL SYSTEM : An interconnection of components forming a system configuration that will provide a desired response. PROCESS: The device, plant, or system under control. The input and output relationship represents the cause and effect relationship of the process. OPEN LOOP CONTROL SYSTEM: Utilize a controller or control actuator to obtain the desired response. CLOSED LOOP CONTROL SYSTEM: Utilize feedback to compare the actual output to the desired output response. BASIC CONCEPTS OF A CONTROL SYSTEM: 1. PLANT: A physical object to be controlled such as a mechanical device, a heating furnace, a chemical reactor or a spacecraft. 2. CONTROLLED VARIABLE: the variable controlled by Automatic Control System , generally refers to the system output. 3. EXPECTED VALUE: The desired value of controlled variable based on requirement often it is used as the reference input. 4. CONTROLLER: An agent that can calculate the required control signal. 5. ACTUATOR: A mechanical device that takes energy, usually created by air, electricity, or liquid, and converts that into some kind of motion. 6. SENSOR: A device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. 7. DISTURBANCE: The unexpected factors disturbing the normal functional relationship between the controlling and controlled parameter variations. BASIC REQUIREMENT FOR A CONTROL SYSTEM: 1. STABILITY: Refer to the ability of a system to recover equilibrium. 2. QUICKNESS: Refer to the duration of transient process before the control system to reach its equilibrium. ACCURACY: Refer to the size of steady-state error when the transient process ends.