ROBOTICS COMES OF AGE

ROBOTICS COMES OF AGE

INTRODUCTION TO ROBOTICS The primary thrust of domestic U . S . interest in robotics is the belief that r o b o t s , along with other automation technology, will be an important tool for improving the competitiveness of U . S . manufacturing. The use of robots can lower p r o d u c ­ tion c o s t s , improve the quality of manufactured g o o d s , and reduce workplace h a z a r d s . A clear t h e m e has been the concern that foreign c o m p e t i t o r s , such as the Pacific Rim Countries ( J a p a n ) and E u r o p e (Sweden and G e r m a n y ) , h a v e gained a significant edge over the United States both in using this new p r o d u c ­ tion technology and in establishing a competitive position in the major export m a r k e t for r o b o t s . United States manufacturers are investing increasing a m o u n t s in new forms of automation to increase productivity, reduce product cost, and improve prod­ uct quality and reliability in order to regain some of the domestic and world market share lost to foreign competitors. Robotics is one technology that is being applied successfully to accomplish these objectives. Firms that have incorporated robots into their manufacturing processes have d e m o n s t r a t e d in­ creases in productivity and reductions in manufacturing c o s t s . T h e technology is flexible. R o b o t s can perform as stand-alone machines or as c o m p o n e n t s of an a d v a n c e d computer-integrated manufacturing system, along with c o m p u t e r aided d e s i g n / c o m p u t e r - a i d e d manufacturing ( C A D / C A M ) s y s t e m s , a u t o m a t e d materials-handling e q u i p m e n t , and c o m p u t e r numerically controlled ( C N C ) ma­ chine tools. F o r a robot to function in the manufacturing environment it must perform successfully with respect to repeatability, a c c u r a c y , intelligence, and c o m m u ­ nication. The first t w o work hand in hand, since accuracy is the quality that m a k e s repeatability usable. A c c u r a c y is how close the robot can c o m e to a c o m m a n d e d position. Repeatability is how close the robot can return to the previously " t o u c h e d " position. Intelligence operates through the various sen­ sory capabilities and through high-level language programming. Finally, the 1

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1. Robotics Comes of Age

robot must have the ability to accept and feed back information a n d — i n a growing n u m b e r of c a s e s — i n t e r a c t with other equipment in a manufacturing systems setting. R o b o t s have always excelled in applications where freeing h u m a n s from repetitious tasks or dangerous operating environments w a s a goal. A d v a n c e s in visual, tactile, acoustic, and magnetic sensing capabilities have provided robots with the ability to perform many of the basic manufacturing functions, including visual inspection a n d intricate welding operations. N e w generations of robots are being applied in areas such as finishing, laser and water-jet cutting, assem­ bly, and inspection. Clearly this technology is important n o w and in the future as one of the tools U . S . manufacturers can use to regain competitiveness, both in the domestic market and o v e r s e a s . T h e s e same perceived advantages are spur­ ring many other industrial nations to devote substantial resources to further development of robotics technology, thereby guaranteeing an intensely compet­ itive global robot market into the foreseeable future. Figure 1-1 shows the growth in annual sales of robots in the United States. Robots have b e c o m e o n e of the m o r e visible indicators of the trend toward factory automation. R o b o t s are replacing h u m a n workers in the factories and on the production lines. W h e r e there were once machinists, welders, and painters, there are n o w robots and their support s y s t e m s , many of which are maintained and controlled by the w o r k e r s that were initially displaced by the robots. At first, robots c o m p e t e d on an economic basis with the workers they replaced. T h e early robots were extremely expensive a n d , with a life span of approximately 8 y e a r s , could hardly c o m p e t e with h u m a n w o r k e r s . But as w o r k e r benefits and wages began to increase, the fixed costs associated with robots b e c a m e a reasonable cost alternative. 700 r -

625

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600 570

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500 c o

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300 240

200 190 155 100

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Year Figure 1-1

U.S. annual robot sales.

1986

1987

1988

3

Introduction to Robotics

In the 1970s a few h u n d r e d robots were in u s e . T h e y performed j o b s that w e r e t o o h a z a r d o u s for h u m a n w o r k e r s , or were t o o physically difficult or boring. T h e j o b required of the robot what it required of the worker: limited skill and t h e ability to cope with the specific working conditions. Automobile manufacturers began emphasizing the use of robots in the middle a n d late 1970s. A s the wages of w o r k e r s spiraled even higher, manage­ ment sought to replace manual labor with r o b o t s . T h e result w a s factories with lines of robots that had replaced h u m a n welders. T h e robots performed m o r e consistently, which resulted in increased quality. Painting robots w e r e devel­ oped next b e c a u s e h u m a n s could also not paint as consistently as the r o b o t s . T o d a y , robots are working in a wide variety of manufacturing operations across t h e entire s p e c t r u m of the e c o n o m y . T h e trend is for robots to continue to b e c o m e cost-effective in more and more fields as the wages of h u m a n w o r k e r s continue to increase relative to robot operating costs. Table 1-1 shows the major robotic application areas by their percentage of current application. T h e s e trends show areas of primary interest in robot usage. Although o n e faction of futurists believes that h u m a n s are in danger of being replaced t o m o r r o w by the robot, d o n ' t plan on seeing this h a p p e n . Like h u m a n s , w h o have t a k e n several millenia to evolve, in much the same fashion the robot will d e v e l o p into a m o r e complete entity over time. Presently the robot, even in its current state of evolution, is capable of performing many of the menial, tedious, repetitive, d a n g e r o u s , and otherwise unpleasant chores that o c c u r in the production world. T o perform tasks usually performed by a h u m a n , the robot will require some h u m a n capacities, namely, adaptable hands or grippers, wrist and a r m s with sufficient joints to allow range of motion, strength to meet the task at h a n d , m e m o r y to learn and repeat tasks once learned, vision to locate itself and parts in p r o d u c t i o n , and t h e ability to permit control or supervision of the w o r k performed. Finally, the robot must be as reliable and operate at a speed no less than t h e h u m a n it is to replace. Several attributes are missing from the qualifications of our current robot, as shown in Table 1-2. A robot cannot react to unforeseen c i r c u m s t a n c e s or changing e n v i r o n m e n t s and it lacks the ability to improve performance based on prior e x p e r i e n c e .

Table 1-1 Estimate of U.S. Robot Population by Application

Task Welding Materials handling Machine loading/unloading Assembly Casting Painting and finishing Other applications

Percentage of total 26 22 17 15 11 8 1

1. Robotics Comes of Age

0 Table 1-2 Comparison of Robot versus Human Skills and Characteristics Robot

Human

Action and Manipulation • One or more arms; automatic hand change is T w o arms and t w o legs; multipurpose hands. possible. • Incremental usefulness per each additional arm T w o hands cannot operate independently. can be relatively higher than in humans. • Movement time related to distance m o v e d by Movement time and accuracy governed by F i t f s speed acceleration, and deceleration, and will law. High-precision movements may interfere increase with higher accuracy requirements. with calculation processes. Brain and Control • Fast, e.g., up to 10,000 bits/sec for a small S l o w — 5 bits/sec. minicomputer control. • N o t affected by meaning and connotation of Affected by meaning and connotation of signals. signals. • N o valuation of quality of information unless provided by program. • Error detection depends on program. Good error detection/correction at cost of redundancy. • Very good computational and algorithmic capability by computer. • Negligible time lag. Time lags increased, 1 to 3 sec. • Ability to accept information is very high, limited Limited ability to accept information (10 to 20 only by the channel rate. bits/sec). • Good ability to select and e x e c u t e responses. Very limited response selection; execution (1 sec) responses may be "grouped" with practice.

• Memory capacity from 20 commands to 2,000 commands and can be extended by secondary memory such as cassettes. • Can forget completely but only on command. • "Skills" must be specified in programs.

• Requires training by an experienced human or machine. • Training does not have to be individualized. • N o need to retrain once the program taught is correct.

N o social and psychological needs.

a

Memory • N o indication of capacity limitation.

• Memory contains basic skills accumulated by experience. • Slow storage access/retrieval. • Very limited working register (5 times). Training • Requires human teacher. • Usually individualized is best. • Retraining often needed due to forgetting.

Social • N e e d s considerable support.

From G. Nof, A. Knight, and D . Salvendy, "Effective Utilization of Industrial R o b o t s — A Job and Skills Analysis A p p r o a c h , " AIIE Transactions, Vol. 12, N o . 3, September 1980.

Why Use Robots?

5

WHY USE ROBOTS? O v e r the past several y e a r s , robots have b e c o m e c o m m o n in manufacturing facilities a r o u n d t h e world. If a d v a n c e d manufacturing technology is to b e c o m e a viable reality, robots will need to b e c o m e much more capable in every aspect: from precision to weight capacity to multipurpose programming and applica­ tions. A u t o m a t i o n will be a hallmark of the future factory, a world of c o m p u t e r integrated (Fig. 1-2) and computer-directed work cells each performing a spe­ cific part of t h e overall p r o c e s s of manufacture, from crude metal cutting to precision assembly a n d subsequent packaging. T h e application of a robot will be based on considerable analysis of the entire system implications and h o w this n e w equipment will affect the overall operation. R o b o t s c a n clearly be identified in terms of the functions they perform. • Pick-and-place robots m o v e objects from o n e place to a n o t h e r and po­ sition materials for the manufacturing p r o c e s s . T h e y can perform material handling, grasping, transporting, and heavy-duty handling. • Machine-loading robots c a n , in support of another machine such as a numerically controlled m a c h i n e , accomplish the task of material loading and tool changing.

Figure 1-2 General Electric's computer-integrated manufacturing diesel engine plant. (Courtesy of General Electric.)

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1. Robotics Comes of Age

• Continuous path applications such as welding, spray painting, and heat treating, in which precise rates of motion are required, are within the r o b o t ' s capability. • A s s e m b l y robots can perform many operations in the production p r o c e s s . T h e design of such robots will be a challenge to the ingenuity of the designer, w h o must grapple with the problems of the sophisticated sensing of the parts and their orientation in the workstation. Central to this effort will be the a d v a n c e s required in the development of software algorithms to recognize and identify parts in a r a n d o m orientation and a variety of lighting conditions. Tooling and parts feeders will also be required to support this n e w capability as it c o m e s on line. • Inspection robots will d e p e n d on the knowledge derived in the world of assembly robots and will perform sophisticated m e a s u r e m e n t s . The ro­ bots will position p a r t s , use some measuring devices, determine suitable production definition, and c h e c k for rejection criteria. W h a t additional new j o b s will be created in the factory of the future is still to be determined. T h e r e will certainly be new challenges as we proceed into the next c e n t u r y , as well as new dangers to cope with and new requirements for our robotized w o r k force. Table 1-3 lists the prime reasons for using r o b o t s . T h e laws governing safety in the workplace and the threat of potential injuries are excellent reasons to consider r o b o t s . Many dangerous tasks are performed in factories, and some of these tasks are not appropriate for human w o r k e r s . A good example of such a task is loading and unloading a die cast m a c h i n e , a j o b performed at high t e m p e r a t u r e in an environment polluted with fumes and v a p o r s . M a n y other h a z a r d o u s situations are currently handled by r o b o t s . T h e s e robots include: • welding r o b o t s , which are subjected to sparks, oil leaks, and water spray; • machining r o b o t s , which are subjected to flying chips; • painting r o b o t s , which o p e r a t e in h a z a r d o u s paint fume e n v i r o n m e n t s . T o d a y ' s robots can be usefully employed to accomplish highly structured industrial tasks for which variability can be controlled or engineered out. T h e s e are generally repetitive and programmable t a s k s , such as assembly, spot weld­ ing, spray painting, palletizing and unloading metal forming, and metal cutting. M a n y hands-on tasks that are currently performed by workers will soon be d o n e by r o b o t s . E x p e c t e d uses for robots include heat treating, grinding and buffing, and inspection and assembly. The next generation of r o b o t s , which will

Table 1-3 Reasons for Using Robots (in Rank Order) 1. 2. 3. 4. 5. 6. 7. 8.

Increased profit Reduced labor costs Elimination of dangerous jobs Increased output rate Improved product quality Increased product flexibility Reduced materials waste Reduced labor turnover

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Robots Defined

have integral m a c h i n e vision, tactile s e n s o r s , or audio s e n s o r s , will be able to perform a m u c h b r o a d e r range of tasks in less structured e n v i r o n m e n t s . T h e robot generally will outperform the h u m a n in e x t e n d e d , repetitive, well-defined t a s k s . Significant productivity increases can be e x p e c t e d b e c a u s e of the r o b o t ' s c o n s t a n t p a c e and ability to operate in a multishift e n v i r o n m e n t . A robot is impervious to fatigue and can repeatedly perform complex t a s k s , result­ ing in increased production over e x t e n d e d periods. Its ability to perform repeti­ tive tasks g u a r a n t e e s that after learning a task, the robot will create less waste in production and less r e w o r k , both of which mean less material input to the process. While outperforming h u m a n labor, the robot suffers few of the w e a k n e s s e s inherent in h u m a n s . T h e robot does not get sick, take leave or b r e a k s , or go on strike, and is not susceptible to injury. Its costs are mostly up front a n d , un­ like h u m a n w o r k e r s , it does not get annual raises, health benefits, and retire­ ment pay.

ROBOTS DEFINED 4 Although e v e r y o n e uses the word ' r o b o t , " the mental images conjured up vary from p e r s o n to p e r s o n . In the w a k e of the movie Star Wars, m a n y people visualize R2D2 and C 3 P O (Fig. 1-3) or androids shuttling around the landscape and carrying on intellectual discussions with each other. H o w e v e r , by h u m a n s t a n d a r d s , r o b o t s are still in the e m b r y o n i c stages of development. R o b o t s c o m e in all sizes and s h a p e s ; from a Lincoln Electric C o m p a n y L a s e r Vision M I G Trak Welding Robot (Fig. 1-4) to the robot a r m on the space shuttle lifting over 500 kilograms in a zero-gravity e n v i r o n m e n t . M o r e typical robots are seen in s o m e of the latest automobile commercials in which L e e l a c o c c a takes you for a tour of an auto plant, w h e r e you see a row of industrial robots all taking their turn on a chassis passing before t h e m . This industrial robot is not nearly as flashy as the Star Wars d u o previously mentioned. It d o e s n ' t walk, talk, or s e e ; h o w e v e r , it does perform work. It is usually bolted to the floor, but eventually they will b e c o m e part of a fully mobile system on the factory floor in which they m o v e from one task to another. It has b e e n difficult to establish a usable, generally agreed upon interna­ tional definition of a r o b o t . E x p e r t s use different a p p r o a c h e s in defining the term. It is important to have some c o m m o n understanding to help define the state of the art, to project future capabilities, and to c o m p a r e efforts b e t w e e n countries. Depending on the definition used, for e x a m p l e , estimates of the n u m b e r of r o b o t s installed in J a p a n vary from 20,000 to over 100,000. This variation stems in part from the difficulty of distinguishing simple robots from 4 very flexible robot s y s t e m s . A t e x t b o o k definition of an industrial robot is ' a programmable multifunc­ tional device designed to both manipulate and transport p a r t s , tools, or spe­ cialized implements through variable p r o g r a m m e d paths for the performance of specific manufacturing t a s k s . " Taking this definition apart: • P r o g r a m m a b l e — c a p a b l e of executing stored program or routines resident in its m e m o r y . T h e m e m o r y may be on magnetic t a p e , on c o m p u t e r floppy disk, or in a r a n d o m - a c c e s s m i c r o p r o c e s s o r .

1. Robotics Comes of Age

Multifunctional—capable of being applied to a variety of operations. By inserting o t h e r learned operations stored in o n e of the m e m o r y media, the robot b e c o m e s capable of performing other t a s k s . M a n i p u l a t e — t o handle or use with skill. This will include gripping, hold­ ing, and rotating objects. T r a n s p o r t — c a r r y or c o n v e y from one place to another. T h e work space for any robot will d e p e n d on its design, but once determined the robot must be capable of effective operation in that space. Tools or specialized manufacturing i m p l e m e n t s — u n i q u e tools like spray guns for painting or welding guns for welding, and more c o m m o n tools like drills, grinders, r o u t e r s , e t c . Variable p r o g r a m m e d p a t h s — p r e d e t e r m i n e d and stored directions or maps on the correct and sequential m o v e s necessary to perform a task. T h e path m a y b e defined only by its end points, by m a n y points along its path, or continuously from end to end. Specific manufacturing t a s k s — t h o s e work elements defined or definable, with certain repeatability, that is, not requiring any additional h u m a n intervention o n c e learned. T h e tasks will be limited by our ability to define the step-by-step p r o c e s s e s involved in completing the task.

Figure 1-3

Science fiction robots. (Courtesy of Star Wars, Lucas Films, Inc.)

Robots Defined

Figure 1 -4

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Lincoln's "Laser Vision MIG Trak" welding robot. (Courtesy of Lincoln Electric Company.)

R o b o t s meeting the definition elements are evolving from less complex to more complex machines as follows: 1. Manual manipulators operated by h u m a n s . A c o m m o n example of a manual manipulator is a b a c k h o e , which is an arm guided by an operator. 2. F i x e d - s e q u e n c e pick-and-place r o b o t s — m a n i p u l a t o r s performing a se­ ries of steps specified by mechanical c a m s , switches, or valves. 3. Variable-sequence r o b o t s — i n s t r u c t i o n s are specified by resetting elec­ trical c o n n e c t i o n s . 4. Playback r o b o t s — c a n r e m e m b e r and repeat any operation after being trained by an o p e r a t o r . 5. Numerically controlled r o b o t s — c a n receive instructions via magnetic tape or directly from a c o m p u t e r . 6. Smart or intelligent r o b o t s — c a n modify their own actions by responding to data received from sensors and by using the ability to process that sensory information.

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1. Robotics Comes of Age

This definition of a robot describes the current state of the technology and is generally accepted by the U . S . industry.

ROOTS OF ROBOTICS A r o u n d 1923, the word " r o b o t " c a m e into general use following the publication of Karel C a p e k ' s play R.U.R. (Rossaurrfs Universal Robots). In 1926, robots first a p p e a r e d in the movies in Metropolis, the most celebrated science fiction film of the silent period. The story, set in the year 2000, showed the masters of Metropolis exploiting the w o r k e r s , w h o , like the Luddites in early nineteenthcentury England, ultimately rebelled against the m a s t e r s , the machinery, and the robot Maria. Isaac A s i m o v , in his first robot story, " S t r a n g e Playfellows," published in 1940, featured a friendly robot named Robbie that saved a little girl. Asimov continued to write positive robot stories, trying to counteract what he calls the " F r a n k e n s t e i n c o m p l e x . " A s i m o v , together with J o h n Campbell, then the edi­ tor of the leading science fiction magazine Astounding Science Fiction, began to formulate the T h r e e L a w s of Robotics. With Campbell's help and counsel, Asimov developed the robot characteristics for which he is now famous. The T h r e e L a w s of Robotics are: 1. A robot may not injure a h u m a n being or, through inaction, allow a h u m a n being to c o m e to h a r m . 2. A robot must obey the orders given it by h u m a n beings except where such orders would conflict with the First L a w . 3. A robot must protect its own existence as long as such protection does not conflict with the First or Second law. In his third robot story, " L i a r , " published in May 1941, Asimov introduced the first of the T h r e e L a w s of Robotics and in his fifth story, " R u n a r o u n d , " pub­ lished in March 1942, outlined all three laws for the first time. It was in this story that Asimov coined the word " r o b o t i c s . " The technology of teleoperators received a boost in 1948 when Ray Goertz and others at the Argonne National L a b o r a t o r y built the first mechanical m a s t e r - s l a v e manipulator with force feedback, which enabled an o p e r a t o r to feel w h a t w a s happening to the manipulator on the other side of a wall. While w o r k w a s progressing to improve teleoperators, there was a trend in the United States, mainly p r o m o t e d by the U . S . Air F o r c e , to improve productivity of the machining of aircraft p a r t s . T h e idea for the m o d e r n numerically controlled (NC) machine tool c a m e from J o h n P a r s o n s , w h o , with the help of F r a n k Stulen, convinced the Air F o r c e in 1948 that automatically controlled machine tools could greatly increase the productivity in small and medium lots. T h e s e lot sizes m a k e u p an estimated 7 0 % or m o r e of most manufacturing and almost all of a e r o s p a c e manufacturing. In 1952, a young H a r v a r d M B A , John Diebold, wrote the pioneering work " A u t o m a t i o n , T h e A d v e n t of the Automatic F a c t o r y . " Diebold was thinking on a theoretical level, and in this important work he wrote:

Roots of Robotics

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During the last d e c a d e . . . d e v e l o p m e n t s in the fields of electronics, c o m m u n i c a t i o n s and electrical network analysis have m a d e possible the construction of a wide variety of self-correcting and self-programming m a c h i n e s . T h e s e machines are capable of automatically performing a s e q u e n c e of logical o p e r a t i o n s , similar in many ways to the mental p r o c e s s e s of h u m a n s ; they can correct the errors which o c c u r in the c o u r s e of their o w n operations, and can c h o o s e , according to built-in criteria, a m o n g several pre-determined plans of action. T h e s e recent a d v a n c e m e n t s have been of such importance that they will constitute the first stages of w h a t coming generations will look upon as the second industrial revolution. T h e pioneering g r o u n d w o r k for robotics v/as brought together by the inven­ tive and creative technical expert George Devol. In 1954, Devol was issued a patent for the U n i m a t e , an abbreviation for Universal A u t o m a t i o n . T h e Unimate was a teachable manipulator for programmable part handling. Devol con­ tinued to invent and eventually was a w a r d e d o v e r 40 robotics-related p a t e n t s , which b e c a m e the core of Unimation, the first and most influential robotics company. Until 1956, no one had been purely dedicated to robotics. This changed w h e n George Devol met J o s e p h F . Engelberger at a cocktail party in Connecti­ cut. Engelberger was receptive w h e n Devol told him of his idea for a program­ mable manipulator. Subsequently Engelberger played the role of e n t r e p r e n e u r , s u p e r s a l e s m a n , and spark plug, which, when combined with D e v o l ' s inven­ tiveness and strong patent position, was sufficient to provide the catalyst for the birth of the industrial robot industry. Engelberger later b e c a m e k n o w n as " t h e father of industrial r o b o t s . " B e t w e e n 1956 and 1958, Engelberger, Devol, Maurice J. D u n n e , and George E. M u n s o n visited m a n y automotive facilities of major U . S . builders and other manufacturing plants to better understand the market and the types of potential applications that w e r e best suited to the new concept of the industrial robot. Although Unimation is considered to be the first robot c o m p a n y , in 1959 the Planet R o b o t C o m p a n y was selling pick-and-place robot devices. Planet's sim­ ple machines performed useful functions in industry and were the first c o m m e r ­ cially available industrial r o b o t s . In 1957, the original c o m p a n y Consolidated Controls, supporting Engel­ berger and D e v o l ' s early efforts, decided not to pursue the business and decided to sell off its interests. At this time, Engelberger went to a variety of other c o m p a n i e s and tried to interest them in the business and the robotics technol­ ogy. At the same time, J a m e s H a r d e r at Ford Motor C o m p a n y , w h o was a w a r e of E n g e l b e r g e r ' s difficulties, was pushing for automation at Ford and said that he could use 2000 of the robots immediately. H e was worried that the fledgling robot industry would be set back with the loss of Unimation. Therefore, he circulated the specifications for the Unimate robot to other U . S . manufacturing and industrial c o m p a n i e s , asking t h e m to bid on producing such a machine for F o r d . T h e net result of this twofold a c t i o n — t h e pull from the marketplace (Ford) and the push from E n g e l b e r g e r — w a s that a n u m b e r of large corporations entered the robot b u s i n e s s , including A M F , H u g h e s Aircraft, I B M , S u n s t r a n d ,

12

1. Robotics Comes of Age

and W e s t e r n Electric. F r o m that group, the most viable product, the Versatran robot used by A M F , b e c a m e U n i m a t e ' s leading competitor. In 1958, with enough information in hand and confident that a machine could be p r o d u c e d that would sell, work on the Unimate began. The first Unimate was hydraulically p o w e r e d , had a digital control and a magnetic drum m e m o r y , and used all discrete solid-state control c o m p o n e n t s . This design was extremely innovative at the time. M u c h of the advanced controller design relied on Devol's early work with c o m p u t e r s , m e m o r y devices, and electronics. In 1961, the first of three prototype machines was installed in the General M o t o r s T u r n s t e d t plant in T r e n t o n , N e w Jersey. The robot was to perform die casting w o r k , and was taught by being led through the various steps of the operation, which it then recorded. The robot contained a m e m o r y of approxi­ mately 180 steps, 5 inputs, and 5 o u t p u t s . The market price was about $18,000. It was hoped that the Unimate would be applied for machine-tool loading and unloading, but 12 years passed before Unimates actually began to perform this work. In 1964, h o w e v e r , General M o t o r s , as a result of their own internal studies, decided to use Unimates on their N o r w o o d spot welding line, and placed an order for 66 robots to be used in their new L o r d s t o w n , Ohio plant, which was to be a s h o w c a s e of modern manufacturing technology. This was an e n o r m o u s order, as Unimation was then building only 3 or 4 machines per m o n t h . After the G M o r d e r was filled, Unimation went back to its previous productivity. The industrial robot turned out to be a solution looking for a problem. Engelberger c a m e to realize that nobody needed a robot. Manufacturers were only motivated by saving m o n e y , and a motivated h u m a n w o r k e r could usually outperform an industrial robot. Industry was uninterested in going through the difficulties inherent in installing this new technology; only w h e n foreign c o m p e ­ tition, mainly from J a p a n , started to employ the machines did U . S . management b e c o m e willing to invest the necessary time and m o n e y . While U . S . industry hesitated to buy r o b o t s , in the mid-1980s the J a p a n e s e were showing tremen­ dous interest in robotics. F o r e x a m p l e , whereas Engelberger might talk before a d o z e n managers and engineers in the United States, in J a p a n he would speak before h u n d r e d s of enthusiastic professionals, all eager to learn about the new technology. Engelberger a p p e a r e d on J a p a n e s e television and was often intro­ duced as " t h e father of r o b o t s . " In 1968, Engelberger's Unimation granted Kawasaki the right to build the Unimate industrial robot line in Japan in exchange for royalties. Many other large J a p a n e s e c o m p a n i e s were ready to j u m p into the market at the same time, and " r o b o t f e v e r " was beginning to spread throughout J a p a n e s e industries. The J a p a n e s e w e r e quick to apply the technology because of a labor shortage, a good relationship b e t w e e n the w o r k e r s and m a n a g e m e n t , and, most importantly, the m a n a g e r s ' long-term view on market share and industrial competitiveness based on manufacturing productivity. J o s e p h Engelberger has been tireless in his promotion of the increased productivity that is possible when robots are em­ ployed in manufacturing. The first generation of m o d e r n roboticists and the first generation of modern robots reached their peak at the R O B O T S 6 Trade Show held in Detroit, Michigan, in M a r c h 1982. T h e press heralded the 1980s as the " d e c a d e of the r o b o t ; " predictions of fully a u t o m a t e d , u n m a n n e d factories of the future a b o u n d e d . T h e usually conservative financial community flocked to invest in

13

Robot Technology

robot and sensor c o m p a n i e s based on forecasted sales and r e v e n u e figures. Most importantly, by 1982 the U . S . business leaders were finally making the long-term c o m m i t m e n t to rejuvenate their factories by using a d v a n c e d technol­ ogy that would enable t h e m to be competitive in the international m a r k e t p l a c e . A u t o m o t i v e industries, which have always been the largest users of industrial r o b o t s , w e r e widely seeking robotic solutions to production p r o b l e m s . Major corporations such as I B M , General Electric, and Westinghouse en­ tered the robot business at this time; the Detroit show and conference atten­ d a n c e set an all-time r e c o r d , and the halls were filled with an eager public hoping to catch a glimpse of the near future. Robot vision systems were introduced at this s h o w , and n e w c o m p a n i e s were being formed to market this technology. Also o n t h e horizon w a s t h e shining star of artificial intelligence, which w a s o n c e again on t h e rise and holding great promise for robotics. A n o t h e r significant o c c u r r e n c e in 1981 w a s the formation of G M F , a U . S . based joint v e n t u r e b e t w e e n General M o t o r s and F a n u c Limited that would design, manufacture, and sell robotics s y s t e m s . Eric Mittelstadt w a s elected President and C . E . O . of the n e w c o m p a n y , in which G M and F a n u c shared a 5 0 - 5 0 equity interest. T h e robots sold by G M F are manufactured at the F a n u c facilities in J a p a n , with the exception of some machines built in the United States. Dr. Sieuemon I n a b a , President of F a n u c , sits on the G M F board of directors. W h e n I B M , G E , W e s t i n g h o u s e , and G M entered the robot business, the overall robot m a r k e t changed: past c u s t o m e r s of the existing robot c o m p a n i e s suddenly b e c a m e c o m p e t i t o r s . A realignment of m a r k e t share a n d m a r k e t domi­ nation w a s soon u n d e r w a y . B e t w e e n 1982 and 1986, G M F c a m e to dominate the robot m a r k e t in capturing more than 30% market share, largely because General Motors is the single largest user of industrial r o b o t s . F r o m 1982 o n , the large corporations began buying robot and machine vision c o m p a n i e s and incorporat­ ing t h e m as part of their internal plan to increase productivity by using a d v a n c e d manufacturing technology, thereby gaining a foothold in the factory automation business. T h e r e is still an e n o r m o u s a m o u n t of work to be d o n e . T h e next generation of roboticists are those future engineers, m a n a g e r s , and researchers w h o are still attending universities and working in their research laboratories. T h o s e w h o join the manufacturing industries will apply the latest technology and push productivity levels to a n e w high. All of these workers will be the pioneers of the second generation.

ROBOT TECHNOLOGY Robotics has a dual technological ancestry that has an important influence on discussions about what they a r e , what they can d o , and h o w they are likely to d e v e l o p . T h e t w o ancestral lines are (1) industrial engineering automation tech­ nology, a discipline that stretches historically over a c e n t u r y , and (2) c o m p u t e r science and artificial intelligence technology, which is only a few d e c a d e s old. Ideas about the nature of robots differ according to the importance given to these t w o technological r o o t s . Most m o d e r n industrial robots are extensions of a u t o m a t e d assembly-line

14

1. Robotics Comes of Age

technology. This form of automation historically has not d e p e n d e d on com­ p u t e r s , although microelectronics provides a powerful new tool for extending its capabilities. In this industrial automation view, m o d e r n industrial robots are closely related to numerically controlled machine tools. F r o m such a perspec­ tive, robotics is already approaching the state of a m a t u r e technology. Over the next d e c a d e , the most important impacts of robotics on the e c o n o m y and w o r k force cannot be considered separately from the impacts of industrial automation in general. On the o t h e r hand, m o d e r n c o m p u t e r technology may provide future robots with new " i n t e l l i g e n t " capabilities such as visual and tactile perception, mobil­ ity, or the ability to u n d e r s t a n d instructions given in a high-level natural lan­ guage, such as " A s s e m b l e that p u m p ! " The commercial availability of such capabilities m a y be one or t w o d e c a d e s a w a y . In the view of some c o m p u t e r science r e s e a r c h e r s , robotics will have little significant social impact in the near future. T h e y estimate that, given sufficient research support, a flexible, intelligent robot could be p r o d u c e d for the market within this d e c a d e . A robot of this type will be able to m o v e freely about an u n s t r u c t u r e d e n v i r o n m e n t and perform a wide variety of tasks on c o m m a n d with minimal reprogramming time. This view stresses continuing basic research in c o m p u t e r science related to robotics, particularly in artificial intelligence. Ro­ bots are seen as " s t a n d - a l o n e , " reprogrammable devices capable of performing m a n y tasks other than large-scale, assembly-line applications, for e x a m p l e , small-scale b a t c h manufacturing, mining, or equipment repair. Which of these views is most pertinent in terms of current policy issues will d e p e n d in part on w h e t h e r such an " i n t e l l i g e n t " robot would be economically feasible in the near future and w h e t h e r it would meet a significant need in the industrial sector. In fact, it seems likely that both types of robotics technology will eventually b e c o m e important, but that their economic and social impacts will differ to the extent that they are used for different p u r p o s e s in different e n v i r o n m e n t s . F u r t h e r m o r e , the time scale for widespread adoption will be significantly later for the " i n t e l l i g e n t " m a c h i n e s . R o b o t s are only one c o m p o n e n t of a large collection of related devices and techniques that form the technological base of industrial automation. Mechani­ cal devices that perform tasks similar to those d o n e by m o d e r n industrial robots have existed for centuries. T h e principal difference is that, w h e r e a s so-called " h a r d a u t o m a t i o n " is custom-designed to a particular task, robots are stan­ dardized but flexible and p r o g r a m m a b l e units that can be installed in different e n v i r o n m e n t s with m u c h less customization. T h e r e is a trade-off b e t w e e n the efficiency of hard a u t o m a t i o n and the flexibility of robots. Since machinery will be integrated with the total design of a factory, it may not be useful to distinguish robotics as an independent technology. A fully a u t o m a t e d factory of the future might include the following c o m p o n e n t s : • A computer-aided design (CAD) system that provides a tool for engineers to d e v e l o p n e w p r o d u c t s on a c o m p u t e r using an electronic display screen. T h e data b a s e generated by the c o m p u t e r during the design p h a s e is then used by o t h e r c o m p u t e r i z e d parts of the factory. • Numerically controlled machine tools and other a u t o m a t e d devices that fabricate c o m p o n e n t s of the p r o d u c t and transport and assemble t h e m following instructions generated by the C A D system.

15

Typical Applications

• R o b o t s , also operating u n d e r computer-generated instructions, that trans­ fer materials from station to station, o p e r a t e tools such as welders and spray p a i n t e r s , a n d perform assembly t a s k s . • C o m p u t e r i z e d information systems that keep track of inventory, trace the flow of material through t h e plant, diagnose p r o b l e m s , and e v e n correct t h e m w h e n possible. All of these technologies are currently under d e v e l o p m e n t and are being used in s o m e form. T h e y will likely evolve into c o m p o n e n t s of a fully auto­ m a t e d , flexible manufacturing facility. T h u s , there a p p e a r to be t w o parallel technological t r a c k s along which industrial robots are likely t o d e v e l o p : (1) stand-alone standardized units that will have varying uses in m a n y different e n v i r o n m e n t s a n d (2) robotics technology that is integrated into complete facto­ ries that will t h e m s e l v e s be flexible.

TYPICAL APPLICATIONS Identifying the applications in which robots are most appropriate will b e t h e key to the productivity of our factories of the future. A robot can be the better choice w h e r e a tool or p r o d u c t must be m o v e d independently or in conjunction with a n o t h e r m a c h i n e . T h e categories of manufacturing activities that fit this defini­ tion a r e : • Manipulation o r t r a n s p o r t — m o v e m e n t of parts from o n e place t o a n o t h e r . • P r o c e s s i n g — p a r t s are altered by a tool, that is, drilling, routing, machin­ ing, welding, painting, soldering, or glueing, or are handled by a robot to install c o m p o n e n t s in light manufacturing assemblies. • I n s p e c t i o n — p a r t s are transferred from o n e place to a n o t h e r for inspection and the robot awaits decision from some form of inspector or machine for instructions for its next m o v e . Several of the m a n y areas in which robots are being applied will be e x a m i n e d in an attempt to show the versatility and potential for r o b o t s .

Material

Handling

T h e technological issues involved in current material-handling applications range from the routine to the very complex. In the simplest c a s e s , the " p i c k a n d - p l a c e " p r o c e s s e s , the robot needs only to m o v e to a prescribed location, grasp an object, m o v e to a second prescribed location, and release the object. In the more a d v a n c e d implementations, the robot may use any combination of specially engineered grippers such as magnetic or v a c u u m grippers, some m e t h o d of smooth path control, or various sensors to locate and verify acqui­ sition of the w o r k p i e c e . T h e level of sophistication, then, generally d e p e n d s on the specific needs of each individual implementation. T h e driving factor for robotization of material-handling applications d e ­ p e n d s heavily on t h e w o r k volume. If the batch size is very large, then hard automation is generally m o r e economical than r o b o t s . C o n v e r s e l y , if the batch size is very small, then h u m a n labor is usually more economical than r o b o t s .

16

1. Robotics Comes of Age

H o w e v e r , there m a y b e overriding reasons for using robots in applications w h e r e they would be less economical than other m e t h o d s , including work in an unpleasant or h a z a r d o u s e n v i r o n m e n t , such as a foundry, or highly repetitive or difficult w o r k that would c a u s e fatigue or injury in h u m a n laborers.

Assembly Robotic assembly operations may be performed at a variety of sophisti­ cation levels. F o r easy-mating assemblies, low levels of sensor and path control sophistication are required, while for the more critical assemblies, complex force sensing and machine vision may be necessary. In addition to advanced sensing r e q u i r e m e n t s , critical path control may also be required. The geometry of assembling t w o closely fitted workpieces is not trivial; although a h u m a n can easily c o m p e n s a t e for slight misalignment, a robot cannot always m a k e the minute corrections in position and angle of attack to properly assemble t w o w o r k p i e c e s . Although completely accurate and efficient assembly control m e t h o d s are not yet available, partial solutions to this problem are available and are being used in production. T h e driving force for robotic a s s e m b l y , as for robotic material handling, d e p e n d s on throughput v o l u m e . F o r very large v o l u m e s , hard automation with fixturing s y s t e m s is m o r e economical than robotics, while for very small batches h u m a n labor can be m o r e economical than r o b o t s . F o r those volumes of w o r k w h e r e robots h a v e the potential for being economical, robotic assembly has the advantage of increased consistency over h u m a n labor. Just as for inspection, the high repeatability of the robot affords a higher and more predictable level of quality control than with h u m a n s y s t e m s . A secondary incentive for using robots for assembly involves clean r o o m and h a z a r d o u s or unpleasant environ­ m e n t s . Using a robot for an operation that must be performed in a clean r o o m eliminates the complications of h u m a n preparation for the clean r o o m .

Welding Welding is a p r o c e s s that joins metals by fusing them. The process of spot welding includes the c o m p r e s s i o n of the t w o metals at the point of weld, the weld itself, a short period of cooling, and finally the release of the welded area. T o sustain the welding electrodes over a long period of successive welds, they are water-cooled. M u c h of the p r o c e s s time is spent moving from one weld point to the next. In the a u t o industry, robots are generally synchronized to perform the same welding s e q u e n c e over several chassis at one time. W h e r e welding must be d o n e on heavy metals and over long s e a m s , arc welding is m o r e appropriate. In the arc welding process an inert gas floods the area to be welded and the arc is then struck and sustained b e t w e e n the welding rod and the w o r k p i e c e . T h e t e m p e r a t u r e at the arc rises to sufficient levels to melt the metals and fuse the joint. This form of welding has found application in the joining of a l u m i n u m s , c o p p e r s , magnesiums, and stainless steels. T h e robot is strongly e n t r e n c h e d in welding p r o c e s s e s , and with the a u t o m o ­ bile and aircraft industries as strong supporters and i n n o v a t o r s , the applications will increase in other a r e a s . N o t only can robot welders perform more precisely and m o r e repeatably than a h u m a n welder, but they also d o it f a s t e r — s o m e estimates indicate a three-to-one saving in time. And once again, the h a z a r d o u s e n v i r o n m e n t m a k e s r o b o t s especially useful.

Typical Applications

Spray

17

Painting/Coating

In general, robotic painting and coating operations require a very low level of technological sophistication, for e x a m p l e , sensors are not widely used in painting applications. T h e most critical aspect of the robot technology for painting tasks is smooth path control. In some of the more recent painting applications, h o w e v e r , the robot controller is called on not only to direct the path of the robot and control the painting a p p a r a t u s , but also to coordinate the painting with the m o v e m e n t of an assembly line and with other c o n c u r r e n t operations such as d o o r opening. B e c a u s e robotic painting and coating operations require a minimum level of technology, in combination with the fact that this technology has been available for some time, robots have shown a heavy penetration into the painting indus­ try, especially in automobile paint-spraying applications. In fact, several differ­ ent robot manufacturers have built reputations solely on their paint-spraying robots.

Die Casting Die casting involves the production of parts by injecting metal alloys under high t e m p e r a t u r e and pressure into metal molds or dies. This w a s a pioneer application for robot u s e , and the die casting industry now uses robotics to load the m a c h i n e , q u e n c h the part, unload the machine, and perform rough trimming. E a c h of these operations is within the capability of the robot. S o m e are used in 24-hour o p e r a t i o n s , 7 days a week, with an extremely high degree of success and few d o w n t i m e p r o b l e m s . T h e die-cast operation is an excellent e x a m p l e of h o w robots can replace w o r k e r s in a h a z a r d o u s environment on a 24-hour basis.

Press Operations Presses are used to shape metal into a variety of s h a p e s , from body panels of cars to appliances, and robots are n o w performing the basic operations. T h e pick-and-place robot can pick up a stock metal, place it in the press so that it registers correctly, r e m o v e the finished part, and then either stack it or pass it to the next operation. Press operations are considered to be among the most h a z a r d o u s in the factory, and safety regulations require sophisticated devices that m a k e the press inoperative w h e n h u m a n s inadvertently enter the machine safety z o n e . O v e r the y e a r s , as a result of h u m a n ingenuity, there have been many attempts to defeat these safety m e a s u r e s , and accidents have o c c u r r e d . R o b o t s are best e m p l o y e d in those press operations w h e r e the cycle is relatively slow. S o m e p r e s s e s w o r k at a rate b e y o n d the r o b o t ' s capability to be useful in performing t h e supply and transfer functions. S o m e of these faster operations are n o w serviced by a u t o m a t e d stacking equipment.

Inspection Robotic inspection generally requires the most technologically a d v a n c e d equipment available. As sensor technology i m p r o v e s , inspection applications are b e c o m i n g m o r e varied. Sensing systems currently used for robotic inspec­ tion include two-dimensional and lightstripe machine vision, as well as force

18

1. Robotics Comes of Age

sensing and tactile sensing. In addition, other types of sensing are being imple­ m e n t e d as a d v a n c e s in infrared, ultrasonic, and eddy current sensing technolo­ gies have reduced the price of these sensors to a cost-effective level. Until recently, sensing technology has been either unavailable or uneco­ nomical. F o r this r e a s o n , robot penetration into inspection processes has been slower than e x p e c t e d . As the technologies improve and the prices d r o p , robotic inspection will b e c o m e more c o m m o n . Also, because inspection processes are increasingly coupled to assembly t a s k s , robotic inspection will be employed more with the increase in robotic assembly. The primary reason for using robots in inspection tasks is quality control. T h e consistency and repeatability of the robot and the control algorithms that c o m p a r e the workpiece to a model allow for not only greater but also more consistent levels of quality. One of the most important factors that could in­ crease the use of robotic inspection is not availability of new technologies but rather the need for decreasing the cost and increasing the speed of current technologies. Additionally, three-dimensional real-time vision and precision tactile sensing arrays are very active research areas that, when fully developed, will expand the scope of robotic inspection.

THE ROBOT INDUSTRY T h e principal uses of robots today are welding, spray painting, and a variety of so-called pick-and-place light assembly operations that involve simply picking u p an object and putting it with a specific orientation in a predetermined spot. The automobile industry (Fig. 1-5) has been the largest user of industrial robots, in t e r m s of the value of equipment installed. The following discussion considers the industrial robot to be an extension of manufacturing automation. We do not address possible new robot applications outside of manufacturing, such as u n d e r w a t e r or nuclear equipment repairs. Domestic robot manufacturers appear to fall into four groups: 1. Traditional machine tool manufacturers, such as Cincinnati Milacron, that have developed a broad state-of-the-art robot product line. 2. Firms such as Adept that have specialized in vertical robot m a r k e t s , such as the S C A R A light assembly robot. 3. Large manufacturing firms, such as IBM and General Electric. S o m e of these firms may c h o o s e either to retain the technology for their own use or to market their robots to other c o m p a n i e s . 4. Small entrepreneurial firms (TRC) that develop new, innovative robots. This type of firm has been important in developing new s y s t e m s and could play an important role in robotics. T h e relative importance of these different types of firms in the market place will depend on and, in turn, influence the evolution of robotics technology. The history of the microelectronics market suggests that many innovations in robot­ ics will c o m e from the e n t r e p r e n e u r s . Significant in this regard is the trend among many larger industrial firms to acquire small, innovative firms to either diversify or integrate their traditional product lines with new technologies. Despite improved growth in robot sales this year, the U . S . robotics industry

The Robot Industry

19

Figure 1-5 Robots spot-welding the Sentra passenger car and/or truck cab. (Courtesy of Nissan Motor Manufacturing Corporation U.S.A.)

remains a small, low-volume industry, largely dependent on the automotive and light manufacturing electronics industries for the majority of its r e v e n u e s . T h e industry is currently in a flat growth/sales m o d e b e c a u s e the automotive indus­ try cut back on their capital spending plans in 1989. At present the automobile i n d u s t r y ' s share of annual robotics orders runs about 50 percent, which is down substantially from the beginning of the d e c a d e . As a result of the decline in automotive-related capital expenditures b e t w e e n 1985 and 1989, the robotics industry has increased research and development in vertical applications that

20

1. Robotics Comes of Age

will allow other industries, such as light manufacturing, to apply robotics tech­ nology to their manufacturing p r o c e s s e s . Application a d v a n c e m e n t s in light manufacturing, such as those made dur­ ing 1989 in surface-mount and through-hole technologies, will reduce the robot­ ics i n d u s t r y ' s d e p e n d e n c e on orders from the automotive industry. These types of applications particularly suit the revitalized U . S . electronics and appliance industries. Also, the flexibility, quality control, productivity, and automation requirements of m o d e r n manufacturing ensure the expanding use of robotics in the factory of the future. T h e robotic industry's recent profitability will enable U . S . p r o d u c e r s to devote more time, energy, and funding to application re­ search. The fastest-growing m a r k e t s for robotics are in light manufacturing assem­ bly operations. Recently the electronics industry has seen significant growth, which is influenced partially by d e v e l o p m e n t s in robot s e n s o r s , artificial intelli­ g e n c e , n e t w o r k c o m m u n i c a t i o n s , enhanced a c c u r a c y , and system integration. B e t w e e n 1987 and 1994, U . S . robot revenues are projected to show a c o m p o u n d annual growth rate of 9.7 percent and may reach $879 million by 1994. R e v e n u e s for light industrial robots alone are expected to exceed 50 percent of the total U . S . robot market by 1994. Internationally, the world market for robots was $2.83 billion in 1987 and may reach $4.93 billion by 1994. Imports of robots into the United States are estimated to account for at least 30 percent of domestic c o n s u m p t i o n . Eighty percent of these imports are from J a p a n , which is the dominant force in the world in robot manufacture producing more than half the total. In contrast, the United States and E u r o p e each produce about 20 percent of the world total. T h e r e are about 300 firms producing robots in J a p a n , and one-third of this output is for in-house use only. T h e growth of robots in American industry is tied to the level of long-term investment in new manufacturing m e t h o d s and automation in general. In com­ parison to other leading industrial nations, investment has been dismally low in the United States. Assuming that American corporate management m a k e s a long-term c o m m i t m e n t , the U . S . robotics industry could change markedly over the next decade in r e s p o n s e to demand shifts. As mentioned earlier, the spread of robots to a wider range of light manufacturing industries will make the industry less d e p e n d e n t on the capital spending cycles of the automotive sector. F u r t h e r m o r e , the rise in assembly and materials-handling applications for ro­ bots will bring an increase in d e m a n d for robot systems as opposed to stand­ alone m a c h i n e s . Future success in the U . S . market will go to the supplier who can provide a complete turnkey system to meet u s e r s ' needs. The application of peripherals and systems software for the more complex factory automation solutions will b e c o m e an increasingly important focal area for domestic pro­ ducers. Robotics firms in the United States will remain d e p e n d e n t on offshore c o m p o n e n t s in the manufacture and assembly of robot s y s t e m s . H o w e v e r , the source for these imports may well shift, as the E u r o p e a n C o m m u n i t y appears ready to challenge the J a p a n e s e share of the world market. The Western Eu­ ropean nations have also recently worked out agreements to share the cost of research and d e v e l o p m e n t . This type of joint effort will expedite the develop­ ment of new technology and the closing of gaps where they exist. More impor­ tantly, it will reduce the costs associated with research and development for a n u m b e r of c o m p a n i e s and allow them to spread their research over a wider b a s e .

Impact on Jobs

^1

IMPACT ON JOBS In addition to the potential applications of new robotics technology, a n u m b e r of impacts that the expansion of robotics will have on j o b s have been identified. E a c h of these issues is discussed briefly in this section. • Productivity • Labor - U n e m p l o y m e n t , displacement, or j o b shifting - Positive or negative effects on the quality of working e n v i r o n m e n t (such as e x p o s u r e to h a z a r d s , j o b b o r e d o m , and e m p l o y e r / e m p l o y e e relations) • E d u c a t i o n and training - N e e d for technological specialists - N e e d for a technologically literate w o r k force - N e e d for retraining w o r k e r s

Productivity M u c h of the literature on robotics refers to the contribution that robotics will m a k e t o w a r d improving industrial productivity. Since a major national c o n c e r n is the strengthening of the productivity and competitiveness of U . S . industry, it is important to examine this issue. S o m e e x p e r t s w a r n about exaggerating the importance of robotics in im­ proving productivity. T w o r e a s o n s are offered: 1. Robotics is only one tool in a wide array of technologies available to a u t o m a t e manufacturing and e n h a n c e t e a m w o r k in order to increase industrial productivity. 2. Productivity is a subtle and complex concept with n u m e r o u s definitions and m e a s u r e m e n t s . F u r t h e r m o r e , even after a specific definition is c h o s e n , industrial productivity d e p e n d s on m a n y factors that interact with o n e a n o t h e r . H e n c e , it is difficult to attribute productivity improve­ m e n t s to a n y single technology. T h e s e warnings d o not suggest that robotics is an u n i m p o r t a n t production technology. M o s t e x p e r t s believe it is important; h o w e v e r , they are cautious not to take a n a r r o w view of all technologies w h e n assessing impacts on industrial productivity. Although most applications of robots to date h a v e b e e n m a d e by large firms, the future diffusion of robotics and related technologies will also affect smalland medium-sized b u s i n e s s e s in several w a y s . F o r e x a m p l e , there are likely to be many n e w business opportunities for small firms to develop and p r o d u c e software and specialized types of equipment and to provide s y s t e m integration services. S e c o n d , it can be argued that robotics and flexible a u t o m a t i o n may in some cases lower the minimum e c o n o m y of scale for efficient production, and therefore new manufacturing opportunities for small firms will b e c o m e avail­ able. This situation frequently arises w h e n major equipment technologies change. Capital formation is a n o t h e r issue that has b e e n raised regarding robotics. T h e important question s e e m s to be w h e t h e r there is a d e q u a t e capital to buy the

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1. Robotics Comes of Age

appropriate robot technology that will e n h a n c e a c o m p a n y ' s productivity in three a r e a s : 1. T o fund the modernization of industrial plants for the use of automation technology. T h e financial need would be particularly great if we rebuilt entire plants to m a k e the most effective use of robotics, rather than incrementally i m p r o v e the existing plant. 2. T o fund the construction and evolutionary expansion of U . S . plants to p r o d u c e robots in the quantities necessary to have a significant economic impact. 3. T o fund e n t r e p r e n e u r s w h o wish to develop new types of r o b o t s . T h e importance of the availability of capital for this purpose d e p e n d s on the d e m a n d and desirability of increasingly efficient and economical technology. T h e lack of capital is a very serious impediment to the growth of the robotics industry and to the expansion of robot use in manufacturing. Some experts believe that a tax policy, such as an investment tax credit, that encourages such investment would be an important stimulus.

Labor U n e m p l o y m e n t is an issue that is constantly raised in discussions about the impact of r o b o t s , but the relationship b e t w e e n robotization and e m p l o y m e n t is commonly m i s u n d e r s t o o d . Productivity i m p r o v e m e n t s resulting from the use of robotics and related technologies can affect labor in a n u m b e r of w a y s . T h e s e effects d e p e n d on factors such as: • T h e effects of new technology on the relative proportion of machinery to w o r k e r s (the c a p i t a l - l a b o r ratio) in a given industry. • The extent of change in prices and production volumes for U . S . firms once the new technology is in use. • T h e supply of qualified w o r k e r s with specific j o b skills in a given industry. United States e m p l o y m e n t in a given industry may fall b e c a u s e of produc­ tivity i m p r o v e m e n t s , which by definition enable fewer workers to produce a given volume of p r o d u c t . E m p l o y m e n t in a given industry may remain constant or rise, h o w e v e r , if productivity i m p r o v e m e n t s are combined with increases in production v o l u m e . Effective labor compensation may also rise or fall if produc­ tivity i m p r o v e m e n t s lead to shorter work w e e k s or new product prices or both, depending in large part on production volume and profitability. Finally, average wage levels will change with adjustments in the necessary mix of w o r k e r skills resulting from the implementation of robotics and related technologies. Definitions of u n e m p l o y m e n t , like those of productivity, require distinc­ tions b e t w e e n short-term and persistent j o b loss, and between true unem­ ployment (job loss) and displacement (job shift). For some time, most experts in the United States have argued that m o r e j o b s are created by new technology than are eliminated. H o w e v e r , if these j o b s are in different industries a n d / o r require different skills, the effect on an individual w h o would be replaced by automation could be traumatic. In general, if they have been replaced in a union organization, they will in turn displace s o m e o n e else, a process that ripples through the j o b structure. E v e n though the replaced w o r k e r s may be employed, the opportunity for " n e w h i r e s " is lost as a result of the j o b reduction impact.

Impact on Jobs

23

On the o t h e r h a n d , new j o b s will be created in the production and servicing of robots and related technologies. T h e n u m b e r of j o b s created and the rate at which they a p p e a r will d e p e n d both on growth rate of the robot industry and on the degree to which robot manufacture and repair are themselves a u t o m a t e d . T o a s s e s s the effects of a u t o m a t i o n on future e m p l o y m e n t levels, a baseline must b e established against which j o b loss or gain can be m e a s u r e d . This baseline could b e a simple extrapolation of current t r e n d s , but it also m a y need to be adjusted to reflect t w o other effects: • Virtual e m p l o y m e n t — d o m e s t i c j o b s that were not explicitly eliminated, but that would h a v e existed if robots w e r e not installed. • Virtual u n e m p l o y m e n t — d o m e s t i c j o b s that would have been lost if the plant had not r e s p o n d e d to domestic and international competition by automating. As with productivity, it is difficult to attribute e m p l o y m e n t effects to any single c o m p o n e n t , such as robotics, as part of an entire range of i m p r o v e m e n t s in the manufacturing p r o c e s s . Any examination of the effects of robots on j o b s would need to consider robotics in the m u c h b r o a d e r context of automation technology in general. T h e r e are t w o principal sets of questions concerning u n e m p l o y m e n t . T h e s e questions differ in their focus, in their implications, and in the data collection n e c e s s a r y to analyze them: 1. Will the United States experience a long-term rise in the real u n e m ­ p l o y m e n t rate b e c a u s e of the introduction of robotics and o t h e r auto­ mation? If so, will these effects be differentially felt by geographical location, social class, education level, race, sex, or other characteristics? W h a t might be the e m p l o y m e n t penalty of not automating? 2. Will the use of robots create displacement effects over the next d e c a d e ? H o w will these effects be specific to particular industry classes, geo­ graphical locations, or types of j o b s ? H o w will l a b o r / m a n a g e m e n t nego­ tiations be affected? T h e quality of the working environment is a n o t h e r issue that needs to be a d d r e s s e d . If r o b o t s are employed principally for j o b s that are unpleasant or d a n g e r o u s and if the new j o b s created by robotics are better, the quality of w o r k life will i m p r o v e . In the longer term, productivity increases may also result in a shorter, m o r e flexibly scheduled w o r k week. N e w forms of a d v a n c e d manufacturing technology may in m a n y cases relieve j o b b o r e d o m and resulting w o r k e r dissatisfaction that m a n y m a n a g e m e n t experts h a v e b e e n c o n c e r n e d with. W o r k e r s may be able to use m o r e complex skills and perform a greater variety of t a s k s . F o r instance, they may be able to follow the assembly of a p r o d u c t from beginning to end and a s s u m e greater individual responsibility for the quality of the final product. T h e h u m a n working environment can also be improved by segregating p r o c e s s e s that create hazard­ ous working conditions (such as heat or e x p o s u r e to chemicals) from the section of the factory occupied by h u m a n s . F u r t h e r m o r e , equipping a w o r k e r with a robot helper for s t r e n u o u s activities not only eases j o b stress but also creates e m p l o y m e n t opportunities for those w h o have physical handicaps or other limitations. W h e t h e r t h e s e benefits are realized d e p e n d s in part on h o w industry uses r o b o t s . M a n y labor e x p e r t s are c o n c e r n e d that some uses of robots will not be so salutary. F o r e x a m p l e , s o m e argue that one long-term effect of robotics may be

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1. Robotics Comes of Age

to " d e s k i l l " labor, requiring less ability on the part of h u m a n s as they are incorporated into a mechanized environment. Other experts have pointed out the increased opportunities for employer surveillance of e m p l o y e e s . S o m e unions also fear that a u t o m a t i o n could be used by employers to " d o w n g r a d e " j o b s that require working with a u t o m a t e d s y s t e m s , or that robots might be targeted to replace unionized j o b s first.

Education and Training A n u m b e r of education and training issues are raised in the areas of robot installation, p r o g r a m m i n g , and m a i n t e n a n c e . T h e r e is still a shortage of trained technical experts in the field of robotics, and if there is to be any significant expansion in the p a c e of robot-driven automation, m a n y more c o m p u t e r scien­ tists, engineers, software p r o g r a m m e r s , and technicians will be required in the next d e c a d e . A shortage already exists in many fields of engineering and sci­ e n c e , and it seems to be particularly critical in areas of c o m p u t e r software design and programming. H e n c e , the lag in education and training is not unique to robotics technology, at least in the case of highly skilled j o b s . At the same time, the use of robots has already created some new technical j o b s . Programs have b e e n started at the community college level to train w o r k e r s in robot installation, programming, and m a i n t e n a n c e . There is also a need for a m o r e technologically literate work force, one that has a basic under­ standing of technology and m a t h e m a t i c s . I m p r o v e d technological literacy would provide the following benefits: 1. T o the extent that w o r k e r s would be expected to instruct, oversee the m a i n t e n a n c e of, or repair robot units, they would need some basic under­ standing of c o m p u t e r s and s y s t e m s , both mechanical and electrical. 2. A technologically literate work force would be less likely to resist the introduction of robots and other advanced manufacturing technology. 3. A knowledgeable, technologically skilled w o r k e r would be easier to retrain for a n o t h e r j o b s o m e w h e r e else in the plant. O n e r e a s o n the J a p a n e s e w o r k force seems to welcome robots in their plants is the high level of technological literacy reported for the average J a p a n e s e e m p l o y e e . This would give employers greater latitude in finding another and possibly m o r e skilled j o b for a displaced w o r k e r . If the introduction of robotics into a plant is not to result in u n e m p l o y m e n t , a program of retraining displaced w o r k e r s for new j o b s is n e c e s s a r y . Retraining also will be required for those w o r k e r s w h o remain, for their existing j o b s will change in form and function even if their j o b titles remain the s a m e .

SAFETY Industrial robots have a remarkably good safety record. H o w e v e r , additional precautions (safety s e n s o r s , guard rail/cage, s y s t e m s , o p e r a t o r training) could increase the safety of robots still further. Industrial robots also eliminate some of the h a z a r d s involved in working in many factory e n v i r o n m e n t s , such as machine safety g u a r d s , heat, noise, fumes, and lifting of heavy loads that are e n c o u n t e r e d in using metal presses and painting. The importance of robots for

Safety

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risk control has b e e n especially great since the Occupational Safety and Health Act went into effect. T h e r e are several opportunities for e n h a n c e d robot system safety, including i m p r o v e m e n t s to protect against software and h a r d w a r e failures, fail-safe de­ sign, and the e n h a n c e m e n t of o p e r a t o r training. T h e s e are briefly described in the following sections.

Protection against Software Failures R e d u n d a n c y , though e x p e n s i v e , offers the best protection against software failure. A d o u b l e - r e d u n d a n t system can shut itself d o w n w h e n its t w o com­ p o n e n t s disagree, and a triple-redundant system can use majority logic to over­ ride one failed c o m p o n e n t and continue operation. Both h a r d w a r e and software r e d u n d a n c y are useful. Hierarchical and multiprocessor systems can be m a d e more reliable by data r e d u n d a n c y . Time-outs are a n o t h e r simple and effective failure test; for e x a m ­ ple, a time-out could be used in the interface h a r d w a r e b e t w e e n a robot and its controlling c o m p u t e r . If the c o m p u t e r fails to send the robot interface a keepalive signal, the interface halts the robot. A status check is a third w a y to detect software failure. In a status c h e c k , one c o m p u t e r sends specific data to a second c o m p u t e r , which can tell if the data are self-consistent. The safest way of checking status is to run t w o identical c o m p u t e r s in parallel and c o m p a r e their actions.

Protection against Hardware Failures T h e servo valve is a weak point in a hydraulic system since dirt in the hydraulic fluid can c a u s e the spool to stick in an open position and result in uncontrolled motion of the a r m . A precise servo valve is a very complex and expensive d e v i c e , but it could still be improved by rotating it continuously or back and forth a r o u n d its axis independent of its normal control motion along that axis. This would improve valve operation by reducing static friction in the valve to zero and m a k e the valve more sensitive to small control signals, as well as m a k e it possible to detect a valve clogged by dirt in the fluid since the rotation would stop. S e n s o r s that detect loss of line voltage, pneumatic p r e s s u r e , or hydraulic p r e s s u r e , as well as excessive t e m p e r a t u r e , speed, acceleration, force, and servo e r r o r s , could also be included in the system. Either h a r d w a r e or software could monitor the signals from such s e n s o r s . R e d u n d a n c y in the individual c o m p o n e n t s of robotic devices and safety systems can m a k e the entire device or system more reliable. C o m p o n e n t r e d u n d a n c y can be applied at m a n y levels in a robot s y s t e m ; for e x a m p l e , a robot might have multiple actuators on each joint so that o n e could fail without making the robot drop what it is carrying. Of c o u r s e , this increases the cost of the system, so it may not always be economi­ cally justifiable.

Fail-Safe Design H a z a r d detection s e n s o r s , electrical circuits, and o t h e r c o m p o n e n t s in a safety device can fail. E q u i p m e n t that simulates w h a t e v e r condition the sensor is s u p p o s e d to detect can be added to guard against this, and this equipment

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1. Robotics Comes of Age

would challenge the detection system automatically. If the sensor should fail to respond to a challenge, a warning signal would be generated by the safety device.

Operator Training Accidents cannot be prevented by safety devices alone. Those w h o work with or a r o u n d robots must also be trained in the precautions necessary for their own safety. F o r e x a m p l e , it is educational for w o r k e r s to see a robot snap a 3/8-in. steel rod in half. S o m e of the mistaken assumptions include: 1. If the robot arm is not moving, they a s s u m e it is not going to m o v e . 2. If the robot arm is repeating one pattern of motions, they assume it will continue to repeat that pattern. 3. If the robot arm is moving slowly, they a s s u m e it will continue to m o v e slowly. 4. If they tell the robot arm to m o v e , they a s s u m e it will m o v e the way they want it t o . In s u m m a r y , w o r k e r s must use good c o m m o n sense in all aspects of the robot application and should check each part of the robotics equipment safety as with any other piece of a u t o m a t e d equipment.

INTERNATIONAL LEADERSHIP Substantial investments in E u r o p e and Japan for encouraging the use of robots is increasing the competition in robotics technology development. This c o m p e ­ tition exists on t w o levels: (1) developing and selling robotics technology itself and (2) using robots to p r o d u c e goods more competitively (e.g., automobiles and in light assembly manufacturing). S o m e analysts believe that the directions of robotics-related research are significantly different b e t w e e n the United States and o t h e r nations, notably J a p a n . American researchers emphasize software and highly flexible larger s y s t e m s , while many international laboratories are concentrating on vertical m a r k e t h a r d w a r e solutions. Other analysts maintain that the international state of the art in robotics is superior to that in the United States. In general, such "technological l e a d s " are hard to either prove or disprove. H o w e v e r , there is a c o n s e n s u s that the utilization of robots is more a d v a n c e d in several other nations, such as Japan and S w e d e n , c o m p a r e d to in the United States. Although the international interdependence of robot p r o d u c e r s facilitates the spread of new technology, gaps exist in several areas b e t w e e n the United States and its foreign competition. American firms lead their foreign competitors in a n u m b e r of areas associated with robot peripherals and applications of the m o r e complex robot functions. H o w e v e r , it appears that as a whole American business has been slow to apply these technologies in the production arena. P r o d u c e r s in J a p a n and W e s t e r n E u r o p e are concentrating on closing any tech­ nological gaps in areas w h e r e they lag behind U . S . p r o d u c e r s , whereas they are extending their lead over U . S . suppliers in other areas of technology. In general, our international competitive position is partially driven by the application of

International Leadership

27

r o b o t s , continued research and d e v e l o p m e n t , a c c e p t o r s of U . S . and industrial s t a n d a r d s , and fair international trade a g r e e m e n t s . T h e issue of international competition creates conflicts in i m p o r t / e x p o r t policy. F u r t h e r controls might be placed on import/export of robots either for national security r e a s o n s or to limit foreign access to domestic high technology that increases the competitiveness of U . S . firms. H o w e v e r , such controls also deny U . S . robot manufacturers access to foreign m a r k e t s . E v e n if the total international m a r k e t in r o b o t s w e r e to remain relatively small, robot technology would be a vital c o m p o n e n t in the much larger international market for sales of complete computer-integrated a d v a n c e d manufacturing factories. N o c o u n t r y has p u r s u e d robotics with as much vigor as J a p a n . In the mid-1960s, w h e n J a p a n imported the first industrial r o b o t s , J a p a n e s e industry and g o v e r n m e n t w e r e gaining in industrial strength and making a worldwide push in the a u t o m o t i v e , m o t o r c y c l e , and c o n s u m e r electronics industries. J a p a n appeared to be ideal for the successful introduction of robots: a shortage of laborers to perform the w o r k ; good m a n a g e m e n t / l a b o r relations; stable, farthinking m a n a g e m e n t , not driven by a need for short-term returns on investment and equity; an industrial base that had been largely rebuilt after World W a r II; cooperative efforts a m o n g the universities, g o v e r n m e n t agencies, and industrial giants; a basically clean, rational, and harmonious practice of manufacturing, which leads to an easier implementation of robotic technology; and an emphasis on efficiency and productivity using the simplest technology appropriate. In addition to these factors, J a p a n e s e c o r p o r a t e m a n a g e m e n t views domestic com­ petition as a continual threat to the c o r p o r a t e family's well-being. As a result of the m a r k e t environment and motivation, the J a p a n e s e cap­ tured the lion's share of the world industrial robot market and were far ahead of any other country in the application of industrial r o b o t s . Unlike the U . S . robot industry, w h e r e a b o u t a d o z e n c o m p a n i e s dominate the robot b u s i n e s s , in J a p a n there are 300 manufacturers of robots. In the early 1970s, J a p a n ' s Ministery of International T r a d e and Industry (MITI) recognized that industrial robot technology would be important to Ja­ p a n ' s m o v e m e n t into the international marketplace as a dominant manufacturer. T h u s , M I T I s p o n s o r e d robotic technology research and encouraged the applica­ tion of robots in various leasing programs by stimulating cooperative ventures b e t w e e n J a p a n e s e universities, g o v e r n m e n t , and industries. In 1971, the Japa­ nese Industrial R o b o t Association ( J I R A ) was formed. It was the first profes­ sional robot association ever formed, even though the United States had been using robots for a d e c a d e . This cooperative trade organization consisted of industrial robot builders and its main goal was to disseminate information on industrial robot technology. J I R A was organized with the help and leadership of many J a p a n e s e c o m p a n i e s , particularly K a w a s a k i H e a v y Industries and its executive vice-president and director, U s u n e o A n d o . R e s e a r c h w a s subsequently c o n d u c t e d at many universities throughout J a p a n , including W a s e d a , T o k y o , N a g o y a , and K a t o . T o k y o University and many of J a p a n ' s large c o m p a n i e s have their own research organization, a m o n g them M a t s u s h i t a , Hitachi, K a w a s a k i , Y a s k a w a , Mitsubishi, Seiko, and F a n u c , u n d e r the farsighted m a n a g e m e n t of Seiumon Inaba, President of F a n u c . Until this time, J a p a n ' s strength was in the application of robotic technol­ ogy; h o w e v e r , J a p a n has recently also taken leadership in technology design. M a n y of the robot a r m s used throughout the world are manufactured in J a p a n ,

1. Robotics Comes of Age

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as are an increasing n u m b e r of the controls. One of the most popular robot manipulator designs, the S C A R A robot, was developed under the leadership of Hiroshi M a k i n o , professor of precision engineering at Y a m a n a s h i University. W o r k in u n d e r s e a robotics is being c o n d u c t e d by the Japan Marine Science and Technology C e n t e r ( J A M S T E C ) in Y o k o s u k a . The J a p a n e s e will surely con­ tinue their efforts in the application and development of robotic technology.

NOW AND THE FUTURE T h e robot has existed as a tool for little more than 25 y e a r s . The technology evolved from early d e v e l o p m e n t s in servo m e c h a n i s m s for remote control of naval w e a p o n s and aircraft control s y s t e m s , teleoperator manipulators used in the nuclear industry, and machine tools. T h e s e d e v e l o p m e n t s began in the United States in the early to mid-1950s by George Devol and led to the founding of Unimation, the w o r l d ' s first robot producer. T o d a y ' s U . S . robotics industry is a mix of established robot p r o d u c e r s , a few venture capital g r o u p s , and major robot users (such as IBM and Fanuc) w h o have m o v e d into robot production. Although over 56 U . S . - b a s e d firms partici­ pate in the domestic robot market, most industry revenue is shared among the top 5 p r o d u c e r s , w h o control more than 80 percent of the market. T h e majority of sales are m a d e to firms in the a u t o m o t i v e , electronics assembly, and a e r o s p a c e industries. T h e structure of the U . S . robotics industry has changed dramatically over the past d e c a d e . Beginning in the late 1970s, inflated market growth projections, stimulated by intense media coverage of robots as the technology of the future, fueled rapid growth in the industry. Overly optimistic projections of U . S . de­ mand for robots encouraged J a p a n e s e and E u r o p e a n industrial robot p r o d u c e r s to establish footholds in the U . S . market, either independently or through established U . S . firms. M a n y U . S . p r o d u c e r s , under heavy competitive pres­ sures, looked offshore for suppliers from w h o m they could purchase existing technology and h a r d w a r e at lower cost to them than by using domestic produc­ tion. Several large firms sought to establish themselves as producers for general sale as well as for their o w n use. T h e entry of these c o m p a n i e s , notably General M o t o r s , I B M , and General Electric, had a significant impact on the structure of the U . S . robotics industry and on the market strategies of existing firms. T h e top three U . S . - b a s e d robot p r o d u c e r s — C i n c i n n a t i Milacron, A d e p t , and G M F — illustrated the variety of firms in the industry. Cincinnati Milacron is a machine tool p r o d u c e r that has diversified into robotics. T h e c o m p a n y derives a compar­ atively small portion of its total r e v e n u e s from robot sales. A d e p t , a spin-off from U n i m a t i o n , derives most of its r e v e n u e from the sale of r o b o t s . G M F is a joint v e n t u r e b e t w e e n General M o t o r s and F a n u c Limited of J a p a n that was created in 1982, u n d e r which F a n u c shares its robot design technology with G M ; only part of the G M F p r o d u c t line is manufactured in the United States. G M F has b e e n o n e of the sales leaders in the U . S . robot m a r k e t since 1984; its market share for 1989 is estimated at 31 percent. T h e creation of G M F had a substantial impact on established robot pro­ ducers such as Cincinnati Milacron and Unimation, w h o had focused their marketing strategies on large-volume sales of robots to the automotive industry,

Now and the Future

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particularly spot welding r o b o t s . General M o t o r s , the largest U . S . robot user, n o w p u r c h a s e s most of its robots from G M F . Several competing suppliers have b e e n forced to m o v e into less profitable lower-volume market segments and h a v e suffered a reduction in their overall sales volume and m a r k e t share as a result. At p r e s e n t , the U . S . robotics industry is supported by a substantial level of technology transfer from foreign robot p r o d u c e r s . M a n y U . S . firms h a v e pur­ c h a s e d exclusive or nonexclusive marketing rights from J a p a n e s e and E u r o p e a n robot p r o d u c e r s or h a v e obtained licenses to manufacture these robots in the United States. O t h e r s h a v e entered into joint ventures or technology e x c h a n g e a r r a n g e m e n t s with one or more foreign firms. A majority of U . S . firms market­ ing r o b o t s simply add value to a basic robot manufactured offshore by enhancing its capability through the addition of end effectors, various forms of sensing devices, c o m m u n i c a t i o n s p a c k a g e s , and system integration services. T h e utilization of robots in manufacturing will be the driving force if the trend for factory a u t o m a t i o n is to continue in the 1990s. We n o w h a v e the technology to fully a u t o m a t e our plants; h o w e v e r , America does not h a v e the funding and m a n a g e m e n t vision to m o v e aggressively. O u r worldwide competi­ tors will force us to apply robotics as one of the key manufacturing tools of the next generation.