perm filename NSF.HB[DOC,TOB] blob
sn#052649 filedate 1973-07-02 generic text, type T, neo UTF8
00100 I. THE NEED FOR ADVANCED AUTOMATION
00200
00300
00400 The contributions that advanced automation can make to enhance
00500 productivity in manufacturing are now widely appreciated. Current
00600 interest in advanced computer-oriented automation stems from two
00700 sources. The first is the decreasing cost of computation combined
00800 with an improved understanding of how to apply computation to various
00900 aspects of manufacturing. The second cause is the realization that
01000 many current manufacturing operations, primarily assembly and
01100 inspection, will require complex automation methods which are now
01200 research techniques. The same considerations apply to the automation
01300 of tasks such as laboratory and medical procedures, but the emphasis
01400 has been (as ours will be) on manufacturing. A recent ARPA-sponsored
01500 study [Anderson 1972] in which we participated suggests the following
01600 major benefits from advanced automation:
01700 improved national productivity
01800 reduced prices
01900 increased product quality and uniformity
02000 customization of products
02100 increased job satisfaction.
02200 We would like to add just one comment. As we have seen with other
02300 technological developments such as numerical-controlled tools, there
02400 will be things made which were previously impractical to make. There
02500 is widespread agreement in the technical, industrial and government
02600 communities on the potential benefits of advanced automation. There
02700 is much less agreement on the level of sophistication needed in
02800 automation hardware and software. While there are large application
02900 areas in which specially constructed machines or simple general
03000 purpose devices will prove optimal, we believe that the most
03100 practical solution for intermediate quantities (500 to 100,000) will
03200 be to develop general purpose assembly and inspection devices
03300 controlled by sophisticated programs in digital computers.
03400
03500 These conclusions are supported by our consultation with industrial
03600 management who have manufacturing responsibilities. Programmibility
03700 is necessary even in the automobile industry which has large volume,
03800 but essentially custom assembles each car. This has been repeatedly
03900 emphasized in workshops and private conversations.
04000
04100 Another conclusion is that the process of improving the organization
04200 of manufacturing can make heavy use of computer systems.
04300 Computer-aided design is already in heavy use in semiconductor
04400 industries, and making a beginning in other industries. Inventory
04500 and parts tracking are important facilities in the aircraft industry.
04600 Direct numerical control of several N/C machines by a central
04700 computer is also extensively used. Some effort has been directed in
04800 Europe towards the "group technology" approach of Opits, which
04900 attempts to emphasize commonality by using parts descriptions to
05000 group items which are alike. Evolution of computer-aided
05100 manufacturing depends on integrating these facilities and bringing
05200 more facilities under effective control.
05300
05400 These two systems, programmable automation and computer-aided
05500 manufacturing interact in a beneficial way. An important part of the
05600 development process for programmable automation is the development of
05700 programming systems which actually program assembly devices.
08200
08300 There is one further concept in common among presentations of
08400 automation. Automation must be incremental. This is supported by
08500 numerous considerations: invested capital in existing plants, design
08600 costs for conversion, and the necessity for a sequence of
08700 understandable and predictably profitable steps along the path.
08800
08900 We contend that inserting programmable assembly devices incrementally
09000 into existing factories or new factories with only slight
09100 modifications, demands more from the programmable device. We see
09200 this process at work as industrial robots of the Unimate class slowly
09300 develop more facilities. The simple robot described in the ISI study
09400 [Anderson] does not exist yet; it must still be proven feasible by
09500 demonstration. We outline below some arguments about cost and
09600 productivity factors which follow from programmable assembly. These
09700 arguments follow from compatibility with current manufacturing
09800 design, from economies of scale, and from commonality of technology,
09900 and from desires for quality of product and predictability of the
10000 process. Several studies have indicated some priorities among
10100 directions of automation. The ISI study [Anderson] indicates that
10200 less than 20% of discrete manufacturing is amenable to special
10300 purpose automation. A Chrysler Corporation study indicates that car
10400 assembly labor has first priority in automation; assembly plant
10500 direct labor is 40% of direct corporate labor. The ISI study quotes
10600 a figure of 75% as the fraction of batch produced discrete
10700 manufactures. One conclusion is that "the emphasis in development
10800 should be on simple vision devices and on low-bandwidth tactile and
10900 force sensing feedback". That study indicates that the assembly
11000 process typically accounts for 50 percent of production cost.
11100
11200 We assume that present manipulators have a small but stable market,
11300 and that most will have minicomputers soon (Sundstrand does now).
11400 Will the incremental cost of touch, force and visual sensors be
11500 offset by the opening of new capabilities, and will the cost be
11600 offset by reduced cost of system design for machines which allow
11700 loose alignment tolerances? We estimate that touch and force sensing
11800 will add about 5% to the price of current manipulators of the Unimate
11900 class. We estimate that by 1977, the incremental cost of visual
12000 sensors, a laser ranging device such as we use now,and additional
12100 memory requirements, will add about 15%-20% to current manipulator
12200 prices. If labor costs continue to rise, part of the increase will be
12300 offset, but cost comparisons will not change appreciably over that
12400 time scale unless significant new mechanical designs are made. A
12500 conclusion is that sensor-equipped robots will be available at slight
12600 additional cost. We will discuss the benefits of incremental
12700 improvements to manipulators.
12800
12900 We do not expect mechanical production costs to drop as dramatically
13000 as electronics costs fall with integration. The most promising cost
13100 reduction development would be high-production standard modules such
13200 as robots. As an example, consider the Stanford arm; produced in
13300 unit quantity, parts, manufacturing and assembly costs are
13400 approximately $10K. The arm is much simpler than an automobile; there
13500 is no reason why it should cost more. A smaller, more recent design
13600 costs $3500 each in quantities of two.
13700
13800 At what cost are robots economically viable? This varies enormously;
13900 if they are serving a large and expensive machine, the cost can be
14000 relatively high. Unimation now projects labor costs at $22,000 to
14100 $24,000 per man year averaged over the next 10 years, and assumes a
14200 payoff of 2 years for a projected acceptable cost level of $46,000. A
14300 robot with two arms, minicomputer control, force and touch sensors
14400 could be constructed for under $10K in quantities of 1000 now. To
14500 summarize: two arms (new small Scheinman design) $2000 with hand; arm
14600 drivers and arm interface electronics $1000; force and touch $800;
14700 small computer 8k memory $4500; total $8300. Assuming that the
14800 computer price falls to $1200 by 1978, this will at least compensate
14900 for inflation. Of course, these are small arms, suited for parts
15000 assembly, not automotive body assembly. The larger arms, assuming
15100 slight redesign for cost, would cost about $2500 in units of 1000,
15200 for a total system cost (not price) of $12300. This is the range of
15300 price of present transfer machines which have limited market because
15400 they have limited motion, no control, and are thus locked out of the
15500 economy of scale. There is a dynamic which leads to economy of scale;
15600 the greater the versatility, the wider is the market for
15700 applications. This will be true particularly in small production and
15800 job shop operations which have been difficult to automate. The
15900 larger the production, the more versatility for the same initial cost
16000 as special devices. Also, with high volume, standardization of
16100 maintenance, and availability of parts and service are improved. The
16200 quality of the device is also improved.
16300
16400 The economies of scale in production of assembly modules are matched
16500 by economies of intellectual scale in development of design for
16600 automation. The design process is modularized and easily
16700 communicable; there is a common discipline which can be widely
16800 absorbed; developments of many sources can be integrated. Programming
16900 and training done once for one machine can be transferred to all
17000 machines in a plant, and even transferred nationwide. Functional
17100 modularity has been emphasized in our studies. Modularity is clearly
17200 possible and there is a powerful economic incentive to assemble
17300 widely varying systems from one, two, or three arm modules, force and
17400 touch modules, vision and ranging modules, with planning and
17500 monitoring modules. This would also entail software modularity with
17600 computer-aided mechanical design and job specification for robots on
17700 a local or network time-sharing service.
17800
17900 The alternative is special design for each operation. We expect that
18000 at some point, design will be cheaper with standard robot modules
18100 than with special purpose designs, just as it is now more economical
18200 to use mini-computer controllers than special purpose controllers.
18300 Modularity has the potential to reduce design time and improve
18400 predictability of design time and costs, permitting better planning
18500 and response to competition. To some extent, the dehumanized
18600 industrial worker now fills the role of standard module, so that we
18700 do not expect discontinuous change. The continuity with decades of
18800 experience with design for human versatility in assembly can be
18900 relied upon; robots with some versatility, sensing, contingency
19000 actions, and dexterity will provide a transition to newer schemes
19100 which will evolve more slowly. Another advantage of general purpose
19200 techniques is the ease with which the size of the robot can be scaled
19300 up or down. There appears to be no difficulty in making very large or
19400 very small assembly stations which use essentially the same programs.
19500
19600 Versatile assembly devices have an efficiency advantage in medium
19700 scale and job shop production; their utilization efficiency can be
19800 higher because versatility allows a variety of operations to be
19900 scheduled at one station. The availability of computers for
20000 production scheduling will allow the flexibility to be used to
20100 advantage. Robots would also have longer life over which to amortize
20200 costs, since they could function with greatly changed production
20300 operations, and evolve with new hardware and software modules. They
20400 would have higher reliability, since they would have monitoring,
20500 contingency action, and error recovery. They would be self-aligning,
20600 self-calibrating, and self-testing.
20700
20800 With simple devices, inspection and assembly operations must be
20900 broken down into small operations with transfer operations between.
21000 This introduces extra transfer devices with orientation-preserving or
21100 re-orienting steps, and overlapping operations which can be combined
21200 in an advanced device. The extra cost of jigs and fixtures, and of
21300 stopping assembly lines adds to the cost of special purpose
21400 automation. Robots can cut down on real estate, since several
21500 operations can be done at one station.
21600
21700 Because of the adaptibility of work stations, production runs can be
21800 smaller, with less capital tied up in inventory and unused machines.
21900 There can be better response to the needs of high technology industry
22000 which often requires small quantities. There has been difficulty in
22100 meeting the tight tolerances necessary for operation of
22200 non-intelligent devices. It is hard to estimate the value of systems
22300 which work within current industrial tolerance, rather than requiring
22400 radical improvements in engineering practice, but that continuity
22500 does seem important.
22600
22700 Serious issues arise in the development of robots with simple sensory
22800 systems. Some evaluation issues should be settled by demonstration,
22900 since much sharper analyses can be made this way.
23000
23100 There is already a significant degree of industrial involvement in
23200 computer-aided assembly. GM Research Lab has demonstrated a wheel
23300 mounting operation using visual alignment. IBM has a small robot
23400 project. Hitachi has demonstrated a robot with touch and a system
23500 with visual identification of objects on a conveyor belt, with visual
23600 control of manipulation. Can industry be expected to adequately
23700 support this development? Development of primitive robots is an
23800 evolutionary process, not a single product development. The area is
23900 too big; the payoffs are huge and the investment level is large.
24000 Also, traditionally, industry has been dependent on suppliers. But
24100 with the exception of IBM, the suppliers are smaller and less able to
24200 risk the development. Management techniques require inordinate
24300 return on capital. An alternative support could come again from the
24400 military. The ARPA study and the history of numerical controlled
24500 machine tools are natural consequences of the vast military
24600 procurement in technologically advanced products. In the case of N/C,
24700 funds could be diverted from an outmoded technology to development of
24800 devices which were essential to production plans for the future. It
24900 is high technology products which are most competitive
25000 internationally in the civilian economy. The record of government
25100 investment in numerical control, solid state electronics, computers,
25200 and electro-optical devices has been very productive. However, in
25300 large scale development of civilian products and international
25400 markets, foreign governments have taken the lead. The development of
25500 general purpose assembly devices will benefit manufacturers in a
25600 broad spectrum of industry, particularly medium scale manufacturing.
25700 It is an appropriate area for governmental action to help meet a
25800 national need.
25900
26000 Given sensor-equipped robots at little extra cost over current
26100 senseless robots, they will have visual ability to sense color,
26200 strong contrasts in brightness, recognize known objects from two
26300 dimensional outlines (top view of flat object) or three dimensionally
26400 using depth, to a certain extent they will be able to recognize three
26500 dimensional objects using monocular recognition. They will be able
26600 to visually align mating parts in assembly operations, increase
26700 reliability by self- calibration and flaw and disaster detection, and
26800 permit large tolerances in parts transfer, even permitting parts to
26900 be taken from a bin. Several of these abilities are not yet
27000 available in the laboratory, but with known conditions and objects,
27100 and some engineering (e.g. color coding) are achievable within the
27200 time span of the proposed project.
27300
27400 The major determinant of the economic impact of assembly robots will
27500 be the extent of their capabilities. Assessing and extending these
27600 capabilities is the principal goal of the proposed project.
27700