Page 63 - Modern Control Systems

Exercises 37

f. Closed-loop feedback The result of making a judgment about how much
control system compromise must be made between conflicting
criteria.
g. Flyball governor An interconnection of elements and devices for a
desired purpose.
h. Specifications A reprogrammable, multifunctional manipulator used
for a variety of tasks.
i. Synthesis A gap between the complex physical system and the
design model intrinsic to the progression from the
initial concept to the final product.
j . Open-loop control The intricate pattern of interwoven parts and
system knowledge required.
k. Feedback signal The ratio of physical output to physical input of an
industrial process.
1. Robot The process of designing a technical system.
m. Multivariable control A system that utilizes a device to control the process
system without using feedback.
n. Design gap Uncertainties embodied in the unintended
consequences of a design.
o. Positive feedback The process of conceiving or inventing the forms,
parts, and details of a system to achieve a specified
purpose.
p. Negative feedback The device, plant, or system under control.
q. Trade-off The output signal is fed back so that it adds to the
input signal.
r. Productivity An interconnection of components forming a
system configuration that will provide a desired
response.
Engineering design The control of a process by automatic means.
Process The adjustment of the parameters to achieve the most
favorable or advantageous design.
u. Control system The process by which new physical configurations are
created.
Automation A mechanical device for controlling the speed of a
steam engine.

EXERCISES

Exercises are straightforward applications of the concepts c. Nongravitational acceleration
of the chapter. d. Rotational position (or angle)
The following systems can be described by a block diagram e. Rotational velocity
showing the cause-effect relationship and the feedback (if f. Temperature
present). Identify the function of each block and the de- g. Pressure
sired input variable, output variable, and measured vari- h. Liquid (or gas) flow rate
able. Use Figure 1.3 as a model where appropriate. i. Torque
j . Force
E1.1 Describe typical sensors that can measure each of E1.2 Describe typical actuators that can convert the fol-
the following [93]: lowing [93]:
a. Linear position a. Fluidic energy to mechanical energy
b. Velocity (or speed) b. Electrical energy to mechanical energy