Skip to main content
main-content

Über dieses Buch

The authors and editors of this Handbook have attempted to fill a serious gap in the professional literature on industrial automation. Much past attention has been directed to the general concepts and philosophy of automation as a way to convince owners and managers of manufacturing facilities that automation is indeed one of the few avenues available to increase productivity and improve competitive position. Seventy-three contributors share their knowledge in this Handbook. Less attention has been given to the "What" and "How" of automation. To the extent feasible and practical within the confines of the pages allowed, this Handbook concentrates on the implementation of automation. Once the "Go" signal has been given by management, concrete details-not broad definitions and philosophical discussions-are required. To be found in this distinctly different book in the field are detailed parameters for designing and specifying equipment, the options available with an evaluation of their relative advantages and limitations, and insights for engineers and production managers on the operation and capabilities of present-generation automation system components, subsystems, and total systems. In a number of instances, the logical extension of current technology into the future is given. A total of 445 diagrams and photos and 57 tables augments detailed discussions. In addition to its use as a ready reference for technical and management personnel, the book has wide potential for training and group discussions at the college and university level and for special education programs as may be provided by consultants or by "in-house" training personnel.

Inhaltsverzeichnis

Frontmatter

Backdrop to Automation Systems

Frontmatter

Automation: The Multifaceted Technology Overview

Abstract
Automation, possibly more aptly termed automation engineering, is a design engineering philosophy that is directed toward enhancing the automatic nature (sometimes called automaticity) of a machine, process, or other type of work system1. The objective of automation is to cause the work system to be as automatic, that is, self-acting, self-regulating, and self-reliant, as may be possible—but against the practical backdrop of various economic, environmental, social, and other restraints. Because of these restraints, the work systems are only partially automated.
Douglas M. Considine, Glenn D. Considine

Annotated Glossary of General Automation Terms

Abstract
Prior to the 1970s, the automation of industrial production was mainly an extension of mechanization, that is, the use of systems that did not incorporate feedback1. Attempts to automate were largely of an unplanned, scattered, piecemeal nature. Even by the late 1980s, just a few plants worldwide have been automated extensively across-the-board in a way that matches the rather distorted public image of automation on a grandiose scale. Plant-wide, all-at-once automation is found in but a comparative handful of plants that are either new grassroots facilities built from the ground up or plants that have been fully refurbished from the receiving to the shipping dock. In either case, such new or modernized facilities represent tremendous capital outlays that are well beyond the resources of most manufacturing firms.
Douglas M. Considine, Glenn D. Considine

Sensors and Measuring Systems

Frontmatter

Geometric Variables I: Position, Motion, Speed, Velocity

Abstract
In the discrete-piece manufacturing industries as typified by metals, plastics, and other materials fabrication and assembly (machinery, automobiles, aircraft, appliances, electronic equipment, et al.), system geometry is nearly always of the utmost importance to maintaining product quality and throughput (productivity). In the flat goods and continuous-length product industries, geometric measurements, notably of thickness and caliper, are of equal importance in the control of film, foil, paper, wire, cable, and similar products. In the bulk/fluid industries (chemical, petroleum, food processing, among others), the measurement and control of liquid level (position of a fluid interface), the speed of bulk conveyors, and the volumetric feeding for fluid blending are but three examples of critical geometric variables that determine processing quality and profitability.
Douglas M. Considine, Glenn D. Considine

Geometric Variables II: Dimension, Displacement, Thickness

Abstract
Metrological standards and practices grow in importance as more and more automation is applied to manufacturing and processing facilities. Automation enhances the chances of generating scrap and rejects at an exceedingly rapid rate. Higher throughputs and productivity have developed a critical need for very efficient on-line inspection of parts and materials with no degradation of measurement accuracy and resolution. It is interesting to note that one of the forerunners of modern automation was the mass production line introduced several decades ago. These lines could not have succeeded without the concept of interchangeable parts. In turn, this concept would not have been viable had not concentrated attention been paid to establishing in-plant metrological laboratories and the development of more precise measuring techniques—improved interferometers, gage blocks, optical gratings, optical comparators, and the like 1.
Douglas M. Considine, Glenn D. Considine

Geometric Variables III: Object Detection, Proximity, Presence, Nonpresence

Abstract
As pointed out in an earlier article on “Position, Motion, Speed, Velocity,” position is central among the geometric variables. Generally1, in position control and motion systems, control action is taken to establish a position or series of positions that lie along a trajectory or path. In these cases the exact coordinates of position are usually paramount. In object detection, exactness of position is not usually the case (but there are exceptions)—the primary purpose being that of detecting the presence or absence of an object.
Douglas M. Considine, Glenn D. Considine

Machine Vision

Abstract
Machine vision (MV) is part of the larger field of artificial visual perception, which may be defined as seeing, analyzing, and interpreting patterns, scenery, juxtapositions, dimensional magnitude, color, and many other characteristics of the visual environment. This is done with the partial or total substitution of the human visual system by instruments (frequently optical) and computers and/or electronic subsystems.
Larry Werth

Machine Vision: State-of-the-Art Systems

Abstract
Although much attention has been given in the literature to the application of machine vision systems in connection with their use for enhancing the ability and flexibility of robots (so-called smart robots), as of the latter half of the 1980s, statistics indicate that non-robotic applications for machine vision are in the majority. The general categories of such uses include: (1) identification, (2) classification, (3) sorting and measuring, (4) inspection, (5) verification, and (6) quality control. Machine vision systems are enjoying a rather wide acceptance in the electronics manufacturing industry. A number of robotic guidance applications of machine vision, in addition to those mentioned in this article, pertain to automated industrial operations, such as welding, machining, painting, assembly, materials handling, among others.
Douglas M. Considine, Glenn D. Considine

Control Systems

Frontmatter

Control System Architecture

Abstract
Control system functionality and architectures have been evolving steadily for many years. Advances in semiconductor technology have allowed far more processing power to be applied at all levels of plant control than was believed possible only a few years ago. This power will be needed to achieve plantwide automatic control, which includes full integration of process control and plant business systems.
Carl K. Zimmermann

Programmable Controllers

Abstract
As recently as the early 1960s, industrial control systems had been constructed from traditional electromechanical devices, such as relays, drum switches, and paper tape readers2. The control relay was the most widely used device for controlling discrete manufacturing processes. Although these earlier devices are still used today, and many of the problems associated with using them have been eliminated due to technological advances in their design, such approaches continue to suffer from some inherent problems. Relays were susceptible to mechanical failure, they required large amounts of energy to operate, and they generated large amounts of electrical noise. Extreme care had to be taken in the design of relay-based control systems because it was not uncommon for the outputs to “chatter,” that is, turn on and off rapidly when they changed states. The logic of the circuit was dictated by the wiring of contacts and coils, and in order to make changes, more time was required to rewire the logic than was needed in the first place.
Ralph E. Mackiewicz

Programmable Controllers: State-of-the-Art-Systems

Abstract
Because of the very large number of quality manufacturers of programmable controllers (PCs) in the United States, Europe, and Japan, most of whom do not offer a single product but rather a family of related products designed to satisfy the requirements of a large range of applications, selecting a system best suited to a given application has become increasingly difficult during the past several years. Consequently, efforts have been made to construct tabular comparisons of the capabilities and features of PCs. In one tabular system1, the following criteria are listed:
  • Total system I/O
  • Maximum discrete I/O
  • Maximum analog I/O
  • Relay ladder logic
  • High-level language
  • PID capabilities
  • Motion control
  • Documentation
  • PC data highway
  • Type of interface
  • Scan rate
  • Type and size of memory
Douglas M. Considine, Glenn D. Considine

Programming the Programmable Controller

Abstract
In connection with manufacturing automation, software may be defined as the informal conversion of a technical problem into a sequence of instructions (program) that are understood by the programmable controller. Software preparation involves the analysis of problems and the generation of the program by the user. A relatively recent addition to the definition of software is the inclusion of program documentation.
Erich Sulzer

Sequence Controllers—Hardware/Software Trends

Abstract
The application of the function diagram, as described in the preceding article in this Handbook, is further supported by the possibility of projecting and programming a sequence control simultaneously by means of supplemental graphic elements.
Erich Sulzer

Expert System and Model-Based Self-Tuning Controllers

Abstract
The necessity of self-tuning3 controllers is best illustrated by an example. Consider a heat exchanger that uses saturated steam to heat water that flows through its tube bundle. A simple control scheme senses the outlet water temperature and attempts to position the steam valve so that the actual water temperature equals the desired water temperature. Effects of both nonlinearities in the steam valve and changing steam pressure can be reduced by using a second control loop to control the steam flow.4 The slower-acting temperature controller now adjusts the set point of the faster-acting steam flow controller. Unfortunately, a fixed parameter temperature controller has difficulty because of the nonlinear, time-varying behavior of the process. A change in the water flow rate changes the effective delay time and heat transfer characteristics of the process. Gradual fouling of the heat exchanger tubes also changes the process dynamics over time. Good control performance at one operating condition can give way to very poor performance (overdamped or unstable response) at another operating condition.
Peter D. Hansen, Thomas W. Kraus

Numerical Control and Computerized Numerical Control

Abstract
Numerical Control (NC) is the term universally applied to the flexible automation through electronics of general-purpose machine tools. From the late 1950s on, it has made increasing strides on all machine types, bringing with it the benefits of improved productivity and quality.
John Boyle

Computer Numerical Control—State-of-the-Art Systems

Abstract
The application of computer numerical control (CNC) to machine tools is mainly guided by four factors: (1) the volume of work produced during a given period of time, (2) the variety of work produced, (3) the complexity of the workpieces produced, and (4) the desirability of making possible the implementation of the newer manufacturing philosophies, notably computer-integrated manufacturing (CIM) and flexible manufacturing systems (FMS).
Douglas M. Considine, Glenn D. Considine

Actuators and Materials — Transfer Systems

Frontmatter

Antitumor effects

Servomotor and Servosystem Design Trends

Abstract
New products or an upgrading of existing products evolve as suppliers continually evaluate their equipment for improvements to maintain a competitive edge. Whether it be X-Y or point-to-point positioning or a constant or variable speed requirement, an electric motor provides precise motion control in a diverse group of products, ranging from simple conveyors to more complex machine tools and computer peripherals. The more complex systems utilize a four-quadrant servo drive system in conjunction with the servomotor. With emphasis on increased productivity and reliability, the technology in this area is being pushed at a good rate. This is leading to more effective use of the microprocessor in servo loop control. This article explores trends in both servomotors and servosystems and how these trends relate to applications when a manufacturing firm retrofits or upgrades its products.
John Mazurkiewicz

Robots in Perspective

Abstract
In the opinion of some authorities, robots and their application (robotics), as we approach the 1990s, command a somewhat disproportionately high share of the technical and public attention given to the total concept of manufacturing and processing automation. But, with many thousands of robots now installed, their presence is indeed impressive, and there are few sages who do not forecast a bright future for robotics during the remainder of this century.
Douglas M. Considine, Glenn D. Considine

Robot Technology Fundamentals

Abstract
A widely accepted definition of robot is that of the Robot Institute of America: “A robot is a reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices, through variable programmed motions for the performance of a variety of tasks.”
Douglas M. Considine, Glenn D. Considine

A Robot Dynamics Simulator

Abstract
Robotic manipulators are complex (coupled and nonlinear) multi-variable mechanical systems that are designed to perform specific tasks. The versatile robot arm dynamic simulation tool VAST (Ref. 1) has been created to provide a user-friendly working environment in which to simulate and interpret the physical characteristics of robot and actuator dynamics and design and evaluate feedback controllers for robotic manipulators. The development and features of VAST are highlighted in this article. The simulator structure is flexible, versatile, and amenable to further development. The simulator has been designed to become the foundation of a robot-oriented CAD (computer-aided design) system.
Charles P. Neuman

Control of Actuators in Multilegged Robots

Abstract
The increased interest in robotics has led to the integration of robots in automated manufacturing systems. Since the robot’s area of operation (workspace) is limited by its reach, modification of some working environments is required in order to put the workpiece within the robot’s reach. One can also envision applications where considerable distance must be traversed by the robot to reach its workpiece. One example may be in crisis management, where the presence of human operators may not be possible. For instance, in the case of a nuclear reactor accident where the radiation level may exceed the safe level for human operators, a number of robots could be deployed to the accident site for assessment of damages and possible repairs.
Nader D. Ebrahimi

Stepper Motors and Controls

Abstract
Position measurement and motion control are major requirements for numerous applications in the discrete-piece manufacturing industries. Stepper motors, which are inherently digital in nature, are in tune with the digital information handling technology that typifies the modern approach to automation systems found in these industries. Fundamentally high-precision devices, stepper motors are often the method of choice for many open-loop control applications. The line of demarcation between servomotors (feedback—closed loops) and stepper motors for motion control is rapidly becoming less distinct—resulting from a change in design philosophy and improvements in stepper motors, including higher incremental resolution, more stable torques at low speeds, and a reduction of previously speed-sensitive resonances. This topic is explored in more detail later in this article. Stepper motors are also widely used in electronic equipment for disk drives, printers, plotters, medical equipment, and office automation devices.
Douglas M. Considine, Glenn D. Considine

Linear and Planar Motors

Abstract
The fabrication of future integrated circuits will require X-Y table submicron positioning for wafer/mask alignment. This will require a servo drive with a minimum number of moving parts and the virtual absence of mechanical friction. Linear electric motors (LEMs) offer an attractive method for X-F table positioning, since the force transducer and payload can be on the same housing. This means that high accelerations may be achieved without excessive vibrations owing to mechanical resonances.
G. T. Volpe

Solid-State Variable Speed Drives

Abstract
The past two decades have seen rapid growth in the availability and usage of solid-state variable speed drives. Today there is a profusion of types that are suitable for virtually every type of electrical machine from the sub-fractional to the multi-thousand horsepower rating. (See Fig. 1.) Despite the diversity, there are two common properties of these drives: (1) All of them accept commonly available AC input power of fixed voltage and frequency and, through switching power conversion, create an output of suitable characteristics to operate a particular type of electric machine, i.e., they are machine specific. (2) All of them are based on solid-state switching devices. Even though many of the power conversion principles have been known as long as fifty years, when they were developed using mercury arc rectifiers, it was not until the invention of the thyristor in 1957 that variable speed drives became practical.
Richard H. Osman

Materials Motion/ Handling Systems

Abstract
Aside from a few very exceptional cases, which may date back a century or more, factory automation on a rather grand scale was not taken seriously until the post-World War II era. During the 1940s and 1950s, the major steps toward automation were largely confined to various materials-handling situations. Conveying and transferring materials from one workstation to another, or in the case of the transfer machine per se, where several operations were integrated in one machine (an early version of the cell concept), were particularly suited to relay logic. Consequently, well before the appearance of the programmable controller in the very late 1960s, progress in automation tended to be measured by progress in materials handling. In fact, during those earlier days of automation, a vice-president of Ford Motor Company (D. S. Harder) in 1947 defined automation as “the automatic handling of workpieces into, between, and out of machines.”
Douglas M. Considine, Glenn D. Considine

Interfaces and Communications

Frontmatter

Antitumor effects

Communication Standards for Automated Systems

Abstract
There was a time not many years ago when the transmission of information to and controlling devices and the logging of manufacturing and processing data were simply a routine part of the control engineering task. Without question, today, the tail is wagging the dog, so to speak—with communication systems, including the quest for communication standards, now demanding much of the creative thinking of the practitioners of automation technology. And this situation, of course, has arisen for many excellent reasons that have been repeated many times over in the professional automation literature.
Douglas M. Considine, Glenn D. Considine

User Interfacing to Process Computer Systems

Abstract
This article presents a discussion of the evolution of process computing up to the current distributed architectures. The discussion asserts that the current dominant architecture, combined with recent advances in graphics technology, provides powerful tools for creating highly functional, easy-to-use, human-machine interfaces. Concepts important to the design of process computer-user interfaces and an example of a typical process user interaction, performed via an interactive graphics interface, are also presented.
Arthur K. McCready

Local Area Networks (LANs)

Abstract
As automation in the factory increases, the need for communication between computers, controllers, and other “intelligent” machines has become critical. In the past, when factory automation was limited to the use of programmable controllers (PCs), numerical control (NC) of machines, and similar traditional approaches, communication was not a major limiting factor. Each tool was essentially self-contained, and the communication requirement was primarily a user interface for controlling and updating machine operation. With the accelerated growth of automated tools and processes, however, communication between these entities is required to control not only their operation but their interrelationships as well. To this is added the desire to overlay environmental control, energy management, and materials requirements planning (MRP) to the factory operation. The end result is that intercomputer/controller communication has become the largest single problem to be addressed for factory automation. These interrelationships are shown in Fig. 12.
Bruce A. Loyer

Backmatter

Weitere Informationen