Chapter 1 Introduction to Control Systems PDF

Chapter (1) Chapter (1) Introduction to Introduction to Control Control Systems Systems  Introduction Introduction A control system 15 an int...

Chapter (1) Chapter (1) Introduction to Introduction to Control Control Systems Systems  Introduction Introduction A control system 15 an interconnection of components forming a system con- figuration that will provide a desired system response. The basis for analysis of a system 15 the foundation provided by linear system theory, which assumes a cause— effect relationship for the components of a system. A component, or process, to be controlled can ‎‫ عط‬represented graphically, ‎‫ كد‬shown ‎‫ ست‬Figure 1.1. The imnput—-output relationship represents the cause-and-effect relationship of ‎‫ عط‬process, which ‎‫سد‬ turn represents a processing of the input signal to provide a desired output signal. An open-loop control system uses a controller and an actuator to obtain the desired response, as shown ‎‫ ست‬Figure 1.2. An open-loop system 15 a system without feedback. Desired output Input ‎‫عب‬ Process ‎‫ ما‬Output ‎‫ربج‬ |»— Controller ‎‫با‬ Actuator [~ Process [ Oulpul FIGURE 1.1 FIGURE 1.2 Process 10 be Open-loop control controlled. system (without feedback). An open-loop system operates without feedback and directly generates the output in response to an input signal.  Introduction Introduction In contrast to an open-loop control system, a closed-loop control system utilizes an additional measure of the actual output to compare the actual output with the desired output response. The measure of the output ‎‫ كا‬called the feedback signal. A simple closed-loop feedback control system ‎‫ كا‬shown ‎‫ هت‬Figure 1.3. A feedback control system is a control system that tends ‎‫ ما‬maintain a prescribed relationship of one system variable to another by comparing functions of these variables and using the difference as a means of control. With an accurate sensor, the measured output 15 a good approximation of the actual output of the system. Desired output Error Actual a design gap d. a specification Control engineers are concerned with understanding and controlling segments of their envi- ronments, often called a. systems. : a. systems b. design synthesis > trade-offs d. risk An open-loop control system utilizes an actuating device to control a process a. without using feedback b. using feedback a. without using feedback ¢. in engineering design d. in engineering synthesis  Skills Check Skills Check Complete the following sentence: A system with more than one input variable or more than one output variable is known by what name? a. Closed-loop feedback system b. Open-loop feedback system ¢. Multivariable control system ¢. Multivariable control system d. Robust control system Control engineering is applicable to which fields of engineering? a. Mechanical and aerospace d. All of the above b. Electrical and biomedical ¢. Chemical and environmental d. All of the above Closed-loop control systems should have which of the following properties: a. Good regulation against disturbances b. Desirable responses to commands d. All of the above ¢. Low sensitivity ‎‫ ما‬changes ‎‫ سا‬the plant parameters d. All of the above