50 Years Controlling Industrial Processes

8/2/2019 50 Years Controlling Industrial Processes

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ontrorocesses Iooking back at measurement andcontrol technologies during the past50 years, we have seen the field changedramatically. Weve witnessed the transi-tion from manual and mechanical technol-ogy to pneumatic, electromechanical,electronic, and todays digital and infor-mation-based world.Along the way, the tools we use to doour jobs have changed just as dramati-cally, and thus the training and educationwe need to perform our work successfully.Weve gone from drawing boards to com-puter graphics; from rotary telephones todigital fax machines; from slide rules tocalculators; and, of course, from room-size computers to laptops.Driving these changes are the de-mands of a changing world: the need toincrease productivity and quality, globalcompetition, and the need to more safelymanufacture products that are environ-mentally friendly.During the past half-century, measure-ment and control professionals and tech-nicians have made manufacturing history,while theyve helped win wars and groweconomies. From my perspective, heresa snapshot look at some significant meas-urement and control highlights and mile-

stones over the past 50 years.World War I1World War I1 had a dramatic impacton the pace of technological developmentin the United States, including proceduresand instruments used in the control indus-tries. With increased demand for aviationfuel, for example, refineries were redes-

W. Gerald Wilbanksigned and expanded to boost productivity.In 1 940 the average production was30,000 barrels per day; by the end of thewar, that figure had risen to 580,000 bar-rels per day.The U.S. process industries, particu-larly the chemical industry, played a ma-jor role in winning World War 11.Temporarily halting most consumer-ori-ented chemical development, competingchemical and equipment suppliers joinedforces to design, construct, and operatechemical plants crucial to the war effort.

Four projects, in particular, were ofunprecedented scope: the Manhattan Pro-ject, which produced the atomic bomb,and the development of high-octane avia-tion gasoline, synthetic rubber, and peni-cillin. Also, newly-developed lead sulfideinfrared detectors were able to detect pas-sive radiation emitted by military targets,such as aircraft.Control technology not only helpedaid American efforts during the war, italso played a significant role in ending thewar. In 1943, a group ofUS. ArmyCorpsEngineers working on the Manhattan Pro-ject approached Taylor Instruments abouta new method to control the flow of ahighly explosive gas called uraniumhexafluoride. The demands of the K-25project-involving more than 200,000 in-struments-helped spur Taylors inven-tion of the first pressure transmitters.K-25contained several miles of instrumentpanels and helped produce U-235, whichwent into the making of bombs.Computer technology also was pro-gressing. In 1946, the Moore School of

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had grown to about 4,000 members dis-tributtid among 50 sections.

Tra nsisto r and Seeds of D igitalControlThe device that changed everyoneslife in industrialized society-includingthe process control industry-was thetransistor, invented in 1947 by scientistsat AT&Ts Bell Laboratories. Arguablythe most important invention of this cen-tury, the transistor opened the electronicsage, eventually driving out many pneu-matic or air-based controllers of the 1920sand 1930s.Meanwhile, in 1948, Foxboro intro-duced the first pneumatic differentialpressure transmitter, commonly known asthe d/p cell, which still is in use today insome applications. In 1949, the NationalBureau of Standards (NBS) developed adifferential manometer to compare pres-sures of gases, organic vapors, and non-corrosive liquids.

Greater transmission distances duringthe 1950s helped move control rooms fur-ther from the actual processes. Typicalcontrol rooms in the 1950s containedlarge control panels, run by several opera-tors handling several hundred controllersand instruments, mounted and catego-rized by plant unit and area. Large annun-ciator panels alerted the operators tounusual process conditions.The UNIVAC (universal automaticcomputer) began to be installed commer-cially in about 1951. It was the second

commercially available computer, afterMark I. Its ability to process large amountsof raw data did not escape the notice ofcontrol engineers, although it would be afew years before its potential would beproperly explored and applied.

ISA Grows, Gas Chromatog raphyIn 1952, ISA established its nationalheadquarters in Pittsburgh. The first issueof ISA Journal was published in January1954. ISA activities grew rapidly. The11th Annual Conference and Exhibit inNew York, in 1956, drew a record 36,000registrants.In 1952, A.T. James and A.J.P. Martindeveloped the process of gas-liquid chro-matography, a technique for separatingand analyzing a mixture, for which theylater received the Nobel Prize. This tech-nique dramatically improved the speed,accuracy, and sensitivity of previous chro-matographic procedures. By 1956, Beck-

man Instruments was marketing the fiistgas chromatograph.During this period, flowmeters alsocame into their own. In 1954, Foxborobegan marketing an electromagneticflowmeter in the U.S. The next year, ul-trasonic flowmeters hit the market, and by1957, ultrasonic level sensors were devel-oped.The first computer system applied toprocess control is believed to be the DIGI-TAC machine developed in 1954 byHughes Aircraft Co., which generated thefirst major patent in that field.In 1956, ISA leaders testified on thesubject of automation before the Congres-sional Subcommittee on Economic Stabi-l izat ion. They contended thatmeasurement and control practices werenecessary if the available labor was toincrease productivity 37 percent by 1965,as forecast.

Vendors demonstrated electronic con-trollers at ISAs 13th annual show inPhiladelphia in 1958. Meanwhile, in1959, Honeywell introduced the 4-20manalog signal, which became an industrystandard a few years later for calibratingtransmitters. At ISAs 14th annual showin Chicago, Bailey Meter Co. introducedits all-solid-state controller, using transis-tors and magnetic amplifiers. The sys-tems most notable feature was itsautomatic transfer from manual to auto-matic control-a predecessor to todaysbumpless transfer.Westinghouse research in the late1950s led to the discovery of supercon-ductors, which permitted an electrical cur-rent, once started in them, to flow foreverwith no degradation of strength.

Digital Control Arrives,Computers Hit It BigJust as World Wars I and 11spurredR&D and manufacturing in control appli-cations, the rapidly advancing space pro-gram helped advance digital controlapplications throughout the 1960s. Pneu-matic controls were now being replacedby electronic and some digital controls.Direct digital control (DDC), in whichthe computer is responsible for movingcontrol elements, bypassed the early ana-log controllers. Chemical companies inthe U.K. and U.S. used computers in the60s to perform direct digital control.Despite the growing number of instal-lations, computer systems were extremelyexpensive and lacked backup when a fail-ure occurred. The systems typically were

large and had many functians crammedinto them to justify the huge monetaryoutlay by vendor and user alike.In 1964, I B M bet the com-pany-and won big-time-with the in-troduction of System/360, the firstcomputer line to offer upward and down-ward compatibility from the smallest tothe largest models. It set an industry stand-ard that has lasted to this day.With the introduction of the PDP-8 in1965, the worlds first mass-producedminicomputer, Digital Equipment Corp.revolutionized computer design. Smaller,less expensive, easier to program, and fit-ting into a compact equipment cabinet, itwas the first machine with random accesscore memory to sell for under $100,000.The PDP series became an industry stand-ard.At the end of the 1960s, Honeywellintroduced its Vutronik process controlline, allowing operators to make stepchanges in set point by manipulating thePID algorithm, without incurring processupsets.In 1965,Moore Products marketed theSyncro Station, a self-synchronizing con-troller that allowed simple, bumplesstransfer from automatic to manual control.The product represented the final, signifi-cant achievement in pneumatic controls.

The Hardware Era: Auto MakersSpur PLCsIn the late 1960s, General Motors pre-pared specs on what was ultimately tobecome the first programmable logic con-troller (PLC). Requirements for the as-yet-undesigned product included theability to replace electromechanical re-lays, which failed frequently, and also toestablish a system to easily identify wherethe failures occurred. The result was asolid-state, sequential logic solver, de-signed for factory automation and con-tinuous processing applications.The advantages of the PLC were theability to program the system faster andmuch more easily with a much smallerfootprint. In contrast, electromagnetic re-lay panels had to be rewired when controlschemes changed.In 1969, he first astronauts walked onthe moon, bearing Rosemount sensors tomonitor suit pressure, temperature, andoxygen. That same year, Honeywell be-gan R&D on a new distributed controlsystem (DCS). The impetus for such asystem came from the uumanageabilityand unreliability of the large, centralized

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computer control devices. The product,however, would not be unveiled for an-other six years.Following the success of minicomput-ers and PLCs in the 60s, the 70s broughtan era of more advanced instrumentation,including computer control hardware andsoftware. Distributed process control overseveral computers, interconnected in net-works, became a goal for many industrialplants.On the process front, in 1970, Techni-con Corp. introduced a water pollutionmonitor for multiple analysis, capable ofmeasuring up to six water pollutants con-tinuously and simultaneously. A fewyears later, sensor technology advanced asNASA launched a satellite to demonstratethe usefulness of remotely sensing condi-tions on and above earths surface.

In the early O OS, IBM developed thefirst RAM (random access memory) com-puter chip. The development acceleratedaccess times and helped pave the way forthe microprocessor revolution of the 70s.Communications technology chargedahead, with scientists at Coming GlassWorks successfully manufacturing glassfibers, providing the foundation for futurefiber optic cables.

PLCs Advance, DCS BornThroughout the industry, 1974 was aboom year, with instrument makers re-porting record sales, earnings, and back-logs. Shortages and escalating prices forenergy and materials drove their manufac-turing customers to step up the use ofcost-saving control equipment.

Electronic innovations continued, in-cluding the introduction of MOS (metaloxide semiconductor) technology byRCA for the fabrication of integrated cir-cuits. This invention helped make circuitscheaper to produce and facilitated greaterminiaturization.Other significant developments in themid-1970s included the first fully engi-neered microprocessor system for dedi-cated control and data handling;developments in gas chromatography

which improved flexibility, maintainabil-ity, reliability and data handling in indus-trial process control: laser-based,non-contacting flowmeters; and the firstvortex flowmeter.About the same time, Yokogawa, inJapan, and Honeywell, in the U.S., intro-duced the first distributed control systems,marking a significant and far-reaching

change in the way that control systemswould be configured and applied.In 1977, Honeywell introduced thefirst redundant process controller. It al-lowed a single on-line spare controller toprovide complete redundancy for any oneof up to eight other controllers. For thefirst time, operators could view data in thecontrol room, even though the processitself was located remotely. Distributedcontrol truly revolutionized the processindustries, initiating a series of similarhardware introductions over the next 10years.Another significant development in1975 was optical fibers, from AT&TsBell Laboratories. Also at Bell Labs,David Auston invented the fastest elec-tronic switch devised to date by usinglaser light beams to start and stopan elec-trical signal.

ISA Accredited by ANSIIn 1976, the American National Stand-ards Institute (ANSI) approved ISA as anANSI-accredited standards-writing or-ganization, making ISA only the fourthsuch organization to receive that recogni-tion. In 1980, ISA relocated its headquar-ters to Research Triangle Park, N.C.Developments in 1976 included thefirst packaged digital implementation ofconventional PI and PID control algo-rithms: an advanced analog control andinteractive digital display system espe-cially designed for process plant opera-tors; panel-mounted instrument modulesfor split architecture control systems: anda sensitive monitor to detect the amountof mercury to which a worker is exposedduring a workday.In 1977, Johnson Space Center inHouston constructed a facility that couldsimulate an entire space shuttle mission,testing avionics and astronaut responseunder virtually all possible operating con-ditions. Also that year, Honeywell in-vented the f irst microprocessorinstrumentation to combine variable setpoint versus time programming with inte-gral, three-mode control.On the computer front in 1977, IBMannounced development of a 64-bit dy-namic random access (DRAM) array,which achieved a storage element the sizeof one ten-millionth of a square inch.US -DATA, in 1978, introduced the ndustrysfirst microprocessor-based, user-config-urable, interactive color graphic worksta-tion for use with PLCs and industrialcomputers.Meanwhile, Beckman Instru-

ments introduced the first automated di-chotomous particulate sampler to collectand separate aerosols into respirable andnon-respirable fractions, spurring a 100-unit order from the Environmental Protec-tion Agency.

The Software EraThe hardware focus of the 1970s con-tinued into the early %Os, with IBMsintroduction of the personal computer in1981. Lines between DCSs, PLCs, andPCs were blurring as each began to incor-porate features of the other platforms.Vendors now distinguished themselvesthrough software.Neural networks and artificial intelli-gence (AI) applications, while not exactlyexploding in popularity, began to emerge.

Neural networks, designed to reflect orimitate the neural process of the brain,were used in control systems dealing withreactors, modeling, vision, and voice rec-ognition.Expert systems were developed tohelp capture the expertise of long-termoperators, train new operators, and short-en the learning curve. The use of fuzzylogic, a theory developed in 1965, alsoincreased in the %Os, allowing controlengineers to use words such as sort ofhot or very slow, instead of precisenumbers.DCS applications for batch control

continued to growin the 1980s as the costof hardware came down, making the in-vestment more manageable for frequentlychanging applications. Smart transmitterswere launched in 1983, eliminating theneed for digital-to-analog and analog-to-digital conversions to improve system andloop accuracy.Meanwhile, ISAs reputation as aninternational standards-setting body wasbolstered in 1982 when the U.S. Techni-cal Advisory Group for the InternationalElectrotechnical Commission selectedISA as administrative secretariat. Thenext year, ISAs Training Center opened

in Raleigh, N.C. Since then, ISA hastrained more than 40,000 measurementand control professionals in numerous as-pects of instrumentation.The terms MAP (ManufacturingAutomation Protocol) and CIM (Com-puter Integrated Manufacturing) becamebuzzwords in the 1980s-but languishedinto the 90s.

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Sm art Devices, FieldbusIn 1987, Foxboro introduced the firstcontrollers to use artificial intelligencetechnology, while Texas Instruments in-troduced an AI-based system for instru-mentation training and maintenance. Thatsame year, NBS developed an ultrasonicsensor for measuring depth and propor-tion of treated surfaces of steel and metalalloys.Fieldbus became the talk of the indus-try in the late 1980s,with standards devel-opments having been underway since themid-1980s by ISA and the InternationalElectrotechnical Commission.In the late 1980s, DCS, PLC, and PCsoftware packages increased signifi-cantly. With industry standards cominginto play, companies began to considerpartnerships and strategic agreementswith vendors whose products and exper-tise supplemented their own, increasingbusiness for everyone involved.For example, in 1989, Johnson Con-trols and Yokogawa Electric Corp.formed a joint venture to strengthen theirpenetration of North America. Allen-Bradley in alliance with Digital Equip-ment developed a new generation ofindustrial control systems to unite com-munications between the plant floor andmanagement offices. The same year,Hewlett-Packard, Fisher Controls, andCoopers & Lybrand opened a technologycenter that offered a real-world look at afully integrated CIM production systemgeared to the process industry.

Communications and OpenSystemsWhile the 70s and 80s were domi-nated by proprietary systems and soft-ware, the current decade has witnessed arevolution in hardware-independentpackages, leading the way to open sys-tems.Kicking off the 1990s, Wonderwareintroduced InTouch, a Microsoft Win-dows-based human-machine interface ap-

plication generator which allows opera-tors to manage many computer-controlledprocesses from their PCs.The valueof open system architecturehas been debated for some time, with bothvendors and users fearful of degradingsecurity and reliability. However, manycontrol vendors today are spendingR& Ddollars on open architectures and ensuringconnectivity with other systems.

Just as MAP andCIM were buzzwordsof the %Os, MES (Manufacturing Execu-tion Systems) is a buzzword for the 90s.It is an approach to integrating a businessfrom operations data to the business man-agemenvmanagement information sys-tems (MIS) level-areas that previouslywere separate. With MES, process andbusiness data can be accessed andor ma-nipulated to better schedule resources andproduce higher quality documentation.Hardware independence is key to MESsuccess so that information can be trans-mitted throughout the plant.New chips, such as the RISC-basedAlpha chip, Pentium, and PowerPC lines,execute more instructions than previousprocessors, while the client-server archi-tecture is now coming into its own in theprocess world. In this architecture, infor-mation is shared and distributed equallythroughout a network.Other significant technical develop-ments and trends in the 1990s include therapid evolution of graphical user inter-faces; I S0 9000 certification of processcontrol suppliers; increased popularity ofauto-tuning; continued development ofbatch standardization; more neural net-work activity; and increased use of fuzzylogic.

Batch, ISA GrowIn 1993, more than 30,000 peopleattended ISM93 Chicago. Today, ISAsnearly 50,000 members represent virtu-ally every major industry in more than 80countries.

In 1995, long-awaited batch controlstandards have given batch users commondefinitions of terminology, as well as or-ganizational and equipment models.In 1994, in the largest single contractin Rosemounts history-with a$50mil-lion potential-Dow Chemical agreed toa global alliance, standardizing onRosemount pressure transmitters. Thisglobal alliance helped set a purchasingpattern which an increasing number ofusers and vendors have adopted today.ISA continues to be the wellspring forinstrumentation and control, serving theinterests of those who work in this vitallyimportant area of industrial technology.As ISA moves onto its next 50 years,it will continue to foster advancement inthe theory, design, manufacture, and useof instruments, computers, and systemsfor measurement and control. And alongthe way, manufacturing history will con-tinue to be made.

66 IEEE Control Systems

50 Years Controlling Industrial Processes

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