|
Accuracy: |
An
expression describing the ability of a measuring
instrument to show the true value of a measured
quantity. It is generally expressed as the magnitude
of the total error expected in the measurement. It
is usually given as a percent of full scale reading
of the measuring instrument. |
|
Actuator: |
The part of a regulating valve to convert thermal,
electrical, or fluid energy into mechanical energy
to open or close the valve. |
|
Adaptive control: |
A system that modifies
behaviour in response to changes in the dynamics of
the process and the character of the disturbances. |
|
Agent-based system: |
A method to simulate a
manufacturing system in which each component of the
system is an agent that receives input from service
agents and provides a service or outputs to client
agents, |
|
Agile manufacturing: |
A means of thriving in an
environment of continuous change by managing complex
relationships through innovations in technology,
information, and communication, organizational
redesign and new marketing strategies. Adaptation of
a factory to produce new products demanded by a
customer or new market. |
|
AGVS |
Automated guided vehicle
system, vehicles equipped with automatic guidance
equipment that follow a prescribed path, stopping at
various stations to load or unload parts or
materials. |
|
Amplitude ratio: |
The ratio of the amplitude of
the sine wave output to the sine wave input. A
stable system will have all of it's A.R. values
below 1.0 for a variations in input frequency. |
|
Analog signal: |
A signal measurement over time
that is continuous. |
|
Artificial
intelligence (AI): |
The concept that a computer can
be programmed to be capable of learning, reasoning,
adaptation and self-correction. |
|
Artificial neural network:
|
A processing architecture
derived from models of neuron interconnections of
the brain. Unlike typical computers, neural networks
are supposed to incorporate learning, rather than
programming, and parallel, rather than sequential,
processing. |
|
Automated guided vehicle
system (AGVS): |
Vehicle equipped with automatic
guidance equipment that follow a prescribed path,
stopping at each machining or assembly station for
loading or unloading of parts. |
|
Automation: |
(1) The conversion to and
implementation of procedures, processes or equipment
by automated means. (2) Industrial open- or
closed-loop control systems in which the manual
operation of controls is replaced by servo
operation. |
|
Autonomous system : |
A network that is administered
by a single set of management rules that are
controlled by one person, group or organization.
Autonomous systems often use only one routing
protocol, although multiple protocols can be used.
The core of the Internet is made up many autonomous
systems. |
|
Benchmark: |
A fixed point of reference or a
standard for comparison, used to achieve excellence
within the manufacturing firm; an outstanding
example, appropriate for use as a model. |
|
Best practice: |
A process of benchmarking
against competition to find out how the best is
done. |
|
Bill of material: |
A listing of all the
subassemblies, parts and raw materials that go into
a parent assembly. |
|
Bode diagram: |
A drawing used to represent the
system steady state (frequency) response to a sine
wave input of variable frequency. The graph plots
the Amplitude Ratio versus the frequency on a
log-log scale and the Phase Lag versus frequency on
a normal-log scale. |
|
Cascade control: |
A control system in which one
feedback loop is located within another feedback
loop. The two measured variables must be related by
cause and effect and the inner loop must be faster
than the outer loop. |
|
Certainty factor: |
A term assigned to a fuzzy rule
conclusion that expresses the degree of uncertainty
associated with the conclusion should the premise
part be 100% correct. |
|
Changeover time: |
Time required to modify a
system or workstation usually including both
teardown time for the existing condition and setup
time for the new condition; typically associated
with a switch to new product. |
|
Computer-aided design (CAD):
|
The use of high-resolution
graphics in a wide range of design activities,
allowing quick evaluation and modification of
intent. |
|
Computer-aided
manufacturing-CAM: |
The use of computer technology
to generate data to control part or all of a
manufacturing process. |
|
Computer-integrated
manufacturing-CIM: |
The increased integration of
business and manufacturing functions through
application of information technology; the use of
computers in all aspects of manufacturing, with
integration of functions and control in a hierarchy
of computer systems. |
|
Computer numerical control (CNC):
|
The control of motion in an
accurate and programmable manner through use of a
dedicated computer within a numerical control unit
having local data input such that machine tools are
freed from the need for hard-wired controllers. |
|
Concurrent engineering:
|
The restructuring of the
engineering process so that the input of all
concerned parties, including manufacturing, sales
and even customers, are heard from during a
project's conception. |
|
Confidence level: |
A threshold level that must be
met by the premise of a rule in order for the
conclusion statements to be activated. |
|
Continuous-flow production:
|
Production where in products
flow continuously rather than being proportioned
into lots or as a series of batches. |
|
Continuous improvement:
|
A philosophy of making frequent
and small changes to production processes, developed
in Japan; the cumulative results of which lead to
high levels of quality and efficiency. |
|
Continuous process control:
|
The use of transducers
(sensors) to monitor a process and make automatic
changes in operations through the design of
appropriate feedback control loops; such devices
historically have been mechanical or
electromechanical, but now widely use computers and
centralized control. |
|
Control system: |
The deliberate guidance or
manipulation of the elements in a system in order to
achieve a prescribed value or performance of a
system to complete a defined process. |
|
Control variable: |
The variable within a control
system that is manipulated to achieve a desired
response in the output variable. |
|
Critically-damped system: |
If the roots of the
characteristic equation of a second order system are
real and equal, then the system is said to be
critically damped, i.e., on the border between
overdamped and underdamped. |
|
Damping coefficient: |
A measure of the degree of
damping of the oscillations within a control system.
If greater than 1.0, the system is overdamped and no
oscillations will occur. If the damping coefficient
equals 1.0, the system is critically damped. Between
1.0 and 0.0, the system is said to be underdamped
and the oscillations will decline in amplitude over
time. If the damping coefficient is less than 0 then
the system is unstable. |
|
Dark factory:
|
A completely automated factory
with no labour. |
|
Data acquisition system:: |
Any instrument or computer that
acquires data from sensors via amplifiers,
multiplexers and any necessary analog to digital
converters; typically associated with process
industries. |
|
Database: |
A collection of structured
data, independent of any application. |
|
Data highway: |
The name given to the network
in a plant or factory that transfers data between
elements that make up the overall automation system.
|
|
Dead time: |
The time over which no change
in an output variable is observed following a step
change in the input variable. Also known as delay
time. |
|
Dead band: |
A
specific range of values in which an input signal
can be altered without causing a change in the
output signal. |
|
Decision-support tool:
|
A personal computer, client or
application server-based system that uses
memory-based processing to perform rapid simulations
using data drawn from business transaction
processing systems, such as enterprise resources
planning. |
|
Degree of belief: |
A value assigned to a variable
or statement which describes how strong or weak the
system believes that the variable or statement is
true. |
|
Derivative control: |
A controller relationship or
transformation in which the slope of the error-time
curve is used to determine the controller output.
The slope is multiplied by a constant called the
Derivative Time constant. |
|
Digital signal: |
A signal measurement over time
that consists of separate, discrete values generally
with a constant sampling time interval. |
|
Discrete event simulation:
|
A technique often used by
engineers in the design and modification of
production systems, whereby models output
statistical estimates of performance, using graphic
animation to help create a greater understanding of
system dynamics. |
|
Discrete manufacturing:
|
Production of distinct items
such as automobiles and computers. |
|
Distributed Control System (DCS): |
Distributed Control Systems
evolved from centralized process control computers
common in the 1960s. The systems were developed for
continuous-flow processes that required loop,
analog, and limited discrete control. A DCS is a
real-time, fault-tolerant system for continuous and
complex batch-process applications. |
|
Distribution management:
|
The determination of optimal
quantities of each product to be made at each plant
and to be distributed to each warehouse, such that
manufacturing and distribution costs are minimized
and customer demand is met. |
|
Document management system:
|
A procedure that allows users
to store, search and manipulate documents
electronically, and to maintain a library of text
and images in a compact space; most systems also
provide a means for passing documents across a
network. |
|
Dynamic error: |
The time deviation between
output and input of a ramp change. |
|
Dynamic scheduling:
|
Software that refines
production schedules as conditions change. |