Page 74 - Modern Control Systems

48 Chapter 1 Introduction to Control Systems

ANSWERS TO SKILLS CHECK

El True or False: (1) True; (2) True; (3) False; (4) False; Word Match (in order, top to bottom); p, f, h, k, m,
(5) True q, d, 1, n, c, r, s, , j b, e, t, o, u, v, a, i, g
Multiple Choice: (6) d; (7) d; (8) b; (9) c; (10) a;
(11) d; (12) a; (13) c; (14) d; (15) d

TERMS AND CONCEPTS

Automation The control of a process by automatic means. Multiloop feedback control system A feedback control
Closed-loop feedback control system A system that uses system with more than one feedback control loop.
a measurement of the output and compares it with the Multivariate control system A system with more than
desired output to control the process. one input variable or more than one output variable.
Complexity of design The intricate pattern of interwoven Negative feedback An output signal fed back so that it
parts and knowledge required. subtracts from the input signal.
Control system An interconnection of components form- Open-loop control system A system that uses a device to
ing a system configuration that will provide a desired control the process without using feedback. Thus the
response. output has no effect upon the signal to the process.
Design The process of conceiving or inventing the forms, Optimization The adjustment of the parameters to achieve
parts, and details of a system to achieve a specified the most favorable or advantageous design.
purpose.
Plant See Process.
Design gap A gap between the complex physical system
and the design model intrinsic to the progression from Positive feedback An output signal fed back so that it
the initial concept to the final product. adds to the input signal.
Disturbance An unwanted input signal that affects the Process The device, plant, or system under control.
output signal. Productivity The ratio of physical output to physical input
Embedded control Feedback control system that employs of an industrial process.
on-board special-purpose digital computers as integral Risk Uncertainties embodied in the unintended conse-
components of the feedback loop. quences of a design.
Engineering design The process of designing a technical Robot Programmable computers integrated with a ma-
system. nipulator. A reprogrammable, multifunctional manip-
Feedback signal A measure of the output of the system ulator used for a variety of tasks.
used for feedback to control the system.
Specifications Statements that explicitly state what the
Flyball governor A mechanical device for controlling the device or product is to be and to do. A set of prescribed
speed of a steam engine. performance criteria.
Hybrid fuel automobile An automobile that uses a con- Synthesis The process by which new physical configura-
ventional internal combustion engine in combination tions are created. The combining of separate elements
with an energy storage device to provide a propulsion or devices to form a coherent whole.
system. System An interconnection of elements and devices for a
Measurement noise An unwanted input signal that affects desired purpose.
the measured output signal. Trade-off The result of making a judgment about how to
Mechatronics The synergistic integration of mechanical, compromise between conflicting criteria.
electrical, and computer systems.