RoboMine

Natural frequency:

The frequency at which an underdamped second order system subject to a forcing function of sine wave of that frequency oscillates with amplitude greater than the input. For a third order system there are two natural frequency values while for a fourth order system there are three.

(1) Any system of connected computers and peripherals. (2) In an electrical or hydraulic circuit, a combination of circuit elements. (3) A representation of interconnected nodes or locations with suppliers and customers and a set of connections such as a road or the flow of information or materials.

Networked organization:

A company organized in the form of a group of peers rather than a hierarchy or a system of departments.

Numerical control (NC):

A technique of operating machine tools or similar equipment in which motion is generated in response to numerically ordered commands generated by CAD systems, punched tapes or other communication media.

Nyquist frequency

Digital signal processing requires analog to digital conversion of the input signal. The first step in AtoD conversion is to sample the instantaneous amplitude of the signal at specific times determined by the sampling rate. If the signal contains changes in information at frequencies more than half the sampling rate, the signal will be sampled incorrectly, and the samples will contain spurious components know as Aliasing. The theoretical maximum frequency that can be correctly sampled is half the sampling rate and is called the Nyquist frequency. To avoid aliasing, the sampling rate must be significantly greater than twice the highest frequency present in the signal.

Nyquist plot:

Object-oriented database:

A database used to store objects that are the basis of object-oriented computing in which data as well as references to the procedures used to perform data operations are combined.

Object-oriented software:

Results from modular programming in which each object is a software package containing a collection of related procedures and data that can be reused to shorten application development time. Objects make it easier to customize software systems to mirror actual business processes without negatively impacting the ability to migrate to later software releases.

Offset:

A property of a proportional control system in which the final steady state value is "off-set" from the desired value.

On-off control:

A control system in which the final control element has only two positions - fully open or fully closed. It is also known as two-position control.

Output variable:

(1) The end result of a process or system. (2) Information leaving a device; data resulting from processing. (3) An audio, electric or mechanical signal delivered by an instrument.

Over-damped system:

A system is said to be over-damped when it shows a cyclic response and the oscillations decrease in amplitude over time.

Overshoot:

In a second order system, overshoot is the amount by which the amplitude of the first cycle exceeds the final steady state value.

Pade approximation:

To linearize the delay time in a system, a Taylor Series Expansion is performed on the exponential function and only the first order terms are retained. The technique permits the mathematical analysis of such a system.

Perfect load compensator:

A Feedforward controller system in which the controlled variable produces a response exactly opposite to that of the load change resulting in an overall response that is zero.

PID

Acronym used to describe a control philosophy based on related the error signal to the controller output according to proportional, integral and derivative relationships, each of which are additive.

P & ID

Acronym used to describe diagrams that show process and instrumentation layouts for a plant.

Planning and scheduling systems:

A new generation of planning and scheduling tools that, unlike MRP II, includes constraint models that deal with both materials and capacity. These technologies can be applied along a continuum extending from short-term, plant-floor scheduling to strategic planning of supply chains.

Phase lag:

The time lag of a system expressed as an angular definition to reflect the frequency of a forcing function applied to the system.

Process:

A natural phenomenon marked by gradual changes that lead toward a particular result; a series of actions or operations leading to an end; a continuous operation or treatment in manufacturing; a continuous and regular production executed in a definite, uninterrupted manner.

Process control:

Automatic process monitoring and control by an instrument or computer programmed to respond appropriately to feedback.

Process identification:

A method by which a mathematical model of a process is identified and proven. Changes in the model can also be IDed.

Process load:

Any variable not controlled directly by an existing system but which has a role in determining system output. A load change causes the system to attempt to "regulate" system output.

Process simulation:

Use of a mathematical model by a computer program to envision process design scenarios with real-time visual and numerical feedback. Process optimization and the ability to forecast potential problems are the results.

Process time constant:

This term describes the distribution over time of a system response. For a first order system, it represents that time at which 63.2% of the total response occurs.

Productivity:

A measurement of output for a given amount of input(s). In this document, labour productivity (value-added per employee) is used as the measure of productivity. Increases in productivity are considered critical to raising living standards.

Program:

(1) A complete structured sequence of program statements directing a computer to implement an algorithm. (2) All software programming necessary to solve a problem.

Programmable logic controller (PLC):

A system that controls large numbers of discrete elements using very fast I/O scan times. Today, even the smallest PLCs may be equipped with serial communication and analog control capabilities, and perform arithmetic functions.

Proportional control:

A controller relationship or transformation in which the controller output changes in proportion to the error signal. The error is multiplied by a term called the Controller Gain. 

Protocol:

A standard set of procedures to allow data to be transferred among systems.