Programmable Automation Technologies. Daniel Kandray
organized or connected into a single entity called a manufacturing cell. Manufacturing cells contain an assortment of material handling equipment, including robots and CNC processing equipment. Most often the cell’s activities are orchestrated and directed by a PLC. The robot, CNC equipment, and PLC make the cell “flexible,” as they can be programmed and reprogrammed to perform a wide variety of tasks and produce different products. This single text addresses all three technologies of robotics, CNC, and PLCs.
Yet, “flexible automation” is, in fact, a misnomer. While it is true that the term is appropriate for a specific manufacturing cell in which the technologies are employed, when grouping robotics, CNC, and PLCs under a collective banner, one should highlight what these technologies have in common—namely, “programmability.” Therefore, these technologies are collectively named “programmable automation technologies,” and this book is so titled: Programmable Automation Technologies: An Introduction to CNC, Robotics and PLCs.
While I was writing this text, the nation’s—indeed the world’s—economy plunged into a severe recession. To rise from the current economic turmoil the manufacturing industry must become more productive, a goal that is readily achievable through automation. Programmable automation technologies are the building blocks from which all automation is developed. Hence, the urgent need to improve productivity and become more competitive in the global economy should motivate a significantly greater interest in programmable automation.
The present text is organized into a four sections, which follow a logical sequence of inquiry. The first section is introductory: Chapter 1 provides some background on manufacturing and defines programmable automation. Chapter 2 explains calculation methods used to justify automation expenditures, as motivated by productivity concepts. The second section treats computer numerical control: Chapter 3 introduces CNC technology, Chapter 4 discusses CNC programming, and Chapter 5 addresses CNC simulation. Robotics is covered in the third section in much the same way that CNC was covered in the second section: Chapter 6 introduces robotics technology and Chapter 7 goes over both robotic programming and simulation. (Note that robotic simulation does not have a dedicated chapter.) The last section of the text addresses PLCs: Chapter 8 introduces PLCs and Chapter 9 covers programming and simulation of PLCs. Finally, Chapter 10 concludes the text with a discussion of how all three technologies are brought together to create a programmable automation cell.
Engineering technology students at two- and four-year colleges comprise the book’s primary audience. However, anyone with a technical background and a general understanding of manufacturing and manufacturing processes will find this text useful, as well as to those who wish, simply, to study and understand the use of these technologies.
Engineering technology is an applied science, so its students need to learn much more than theory: They need also practical knowledge, skills, and abilities that will allow them to readily apply automation technology. For this reason, the text offers plentiful examples and identifies and discusses readily available simulation software with which the reader can experiment.
I welcome and look forward to feedback from students, instructors and the general reader. Please write to me at [email protected] and the publisher will forward your messages to me.
Dan KandrayApril, 2010
Introduction to Programmable Automation
Contents
1.1 Introduction to Programmable Automation
1.4 Manufacturing PerformanceMeasures
Objective
The objective of this chapter is to introduce the reader to programmable automation, define automation in general, and to introduce the ideas of when and where automation is applied.
1.1 Introduction to Programmable Automation
Programmable automation technology is a remarkably useful tool for manufacturing engineers/technologists who seek to improve manufacturing systems of their respective industries. It combines mechanical, electrical, and computer technologies that have been developed for very specific automation capabilities. The term “programmable automation technology” actually refers to three individually distinct technologies that have a common thread: programmability. These technologies are computer numerical control (CNC) technology, robotics technology, and programmable logic control (PLC). Each, in some form, either directly or indirectly, is used in almost all modern automation systems—one is unlikely to walk into a modern manufacturing facility without observing one of these technologies in action. This, however, has not always been the case.
Initial migration to programmable automation was gradual, hampered by the complexity, expense, and, in some cases, poor reliability of early systems. Additionally, utilization of the technology required that companies retain technical experts specifically devoted to the implementation, programming, and maintenance of the systems. However, over the last 25 years programmable automation technology has greatly matured: Modern systems are standardized, substantially less complicated and expensive, and extremely reliable. Whereas use of this technology was initially the domain of specialists—particularly engineers—now virtually every member of an engineering or maintenance staff is expected to use the technology at some level. In fact, it is now imperative that mechanical engineers and technologists—who used to avoid “electrical stuff”—have a solid foundation in it. Hence, the goal of this text: to instruct any member of an engineering team so he or she may comfortably delve into the automation arena.
Before we properly define “programmable automation” and develop a full description of its capabilities, we first must present an understandable picture of manufacturing in general. In the following section we explore manufacturing and define some of its key terms. Subsequent sections define automation in general and programmable