~A2!!TheEngineering Society~ ForAdvancing Mobility~ LandSeaAirandSpace® 400COMMONWEALTH DRIVEWARRENDALE, PA15096 chnical mrerlS 881277 Microcontrollers inOff-Highway Applications=A StatusReport FredPollman Sundslrand-Sauer International Off-Highway &Powerplant CongressandExposition Milwaukee. Wisconsin September 12-15.1988Downloaded from SAE International by University of British Columbia, Monday, September 24, 2018Theappearance ofthecodeatthebottomofthefirstpageofthispaperindicates SAE'sconsentthatcopiesofthepapermaybemadeforpersona! orintern<::luse,or forthepersonal orinternaluseofspecificclients.Thisconsentisgivenonthecon~ dition,however, thatthecopierpaythestatedperarticlecopyfeethroughthe Copyright Clearance Cen.ter,lnc.,Operations Center,P.O.Box765,Schenectady, N.Y.12301,forcopying beyondthatpermitted bySections 107or108oftheU.S. Copyright Law.Thisconsentdoesnotextendtootherkindsofcopyingsuchas copying forgeneraldistribution, foradvertising orpromotional purposes, for creatingnewcollective works,orforresale. Paperspublished priorto1978mayalsobecopiedalaperpaperfeeof$2.50 undertheabovestatedconditions. SAEroutinely stocksprintedpapersforaperiodofthreeyearsfollowing dateof publication. DirectyourorderstoSAEOrderDepartment. Toobtainquantityreprintrates,permission toreprintatechnical paperorper~ missionto'usecopyrighted SAEpublications inotherworks,contacttheSAE Publications Division. AlJSAEpi1pfJfSllI'lI Ilbsrl1lcrll<f endind1lJtooin rheSAEG/ob.31Mobo"hryDJfllb<ue. SAEGLOSA!. U06lUTY DATABASE Nopartofthispublication maybereproduced inanyform,in anelectronic retrievalsystemorotherwise, withouttheprior writtenpermission ofthepublisher. ISSNOI48· 7191 Copyright ©1988SocietyofAutomotive Engineers,lnc. Positions andopinionsadvanced inthispaperarethoseof theeuthor(s) andnotnecessarily thoseofSAE.Thaauthor Issolelyresponsible forthecontentofthepaper.Aprocess Isavallabla bywhichdIScussions willbaprintedwiththe paperliltIspublished InSAETmnsactlons. Forpermission topublishthispaperInfullorInpsrl,contactthaSAE Publications Division.Personswishingtosubmitpaperstobeconsidered for presentation orpublication throughSAEshouldsendtha manuscriptora300wordabstractofaproposed manus· criptto:Secmtary, Engineering ActivityBoard,SAE. PrintedInU.S.A.Downloaded from SAE International by University of British Columbia, Monday, September 24, 20188811277 Microcontrollers inOff=Highway Applications-A StatusReport FredPollman Sundstrand-Sauer COMPUTER CONTROLS Computers aremakingasignificant impactinthe off-highway marketplace. Inarecentsurveyofnew construction equipment, thirteenmajorequipment manufacturers arenowofferingcomputers on22 differenttypesofmachines. (3)Almosttwo-thirds of theseusethecomputer foracontrolfunction. Inthe agricultural area,arecentsurveyofthetop50new products had19whichwerecomputer based.(5) Whilethemajorityoftheseweremonitors andnot controls, thebasictechnology isbeingestablished. Acrossalloff-highway marketsthemajorengine manufacturers nowoffercomputer basedfuel controls fortheirpopular engines. Equipment manufacturers seetheuseofcomputers continuing toincrease. (1)(3) Computer controlsformobileequipment are normallyspecially designed "blackboxes"withboth hardware andsoftware tailoredtotheneedsofthe application. Thesecontrollers donotbearany resemblance tothecomputers whichareusedin officesoronin-plantindustrial machines. Formobileelectrohydraulic controlsareprovenandthattheir usewillincrease steadily. Microcontroller technology willbeamajorfactorinthisexpansion. ELECTROHYDRAULIC CONTROLS havebeen usedonmobileequipment formorethan20years withameasured degreeofsuccess. Forthemost part,theelectrohydraulic controlapplications could becategorized asautomatic regulators ofacritical machinefunction. Thetechnology hasusedanalog circuitrywithlogicdevicesandamplifiers builtfrom manydiscreteelectrical components. Duringthis period,thereweresignificant advances madein understanding therigorsofmobileequipment asit relatestoelectrical cir