A.1. Model-Based Testing of Automotive Electronic Control Units. 1 Introduction. 2 Simulation in development of automotive ECUs

Transcription

1 A. Model-Bsed Testig of Autootive Electroic Cotrol Uits Güh, Clees Techische Uiversität Bei, Deprtet of Electroic Mesureet d Digostic Techology Eisteiufer 7, ekr. EN, D-0587 Bei, 9 (0) 99 Itroductio Owig to icresigly strict legisltio, s well s custoer s high expecttios ivolvig drivig cofort, perforce, d sfety, the coplexity of the power tri of oder otor s hs treedously icresed. Absolutely essetil chieveets ecessry to esure cofority with curret d future eviroetl legisltio will iclude dvced egies with ultitude of cotrollble copoets, s well s the pplictio of dvced trsissio systes. It will furtherore be possible to stisfy requireets plced o future s oly by etworkig electroic cotrol uits (s), d by ipleettio of the fuctios distributed throughout these uits. Applictio of iovtive ethods i the developet of s, iput of their dt, d their testig is essetil to successfully coted with the resultig coplexity of softwre, d with the ssocited developet cycles tht hve cosequetly becoe icresigly shorter. Moutig cost squeezes dditiolly rule out y luxury of cost rises i such work. I cotrst to developet d testig i rod trils exclusively prcticed i eier yers, siultio i softwre developet d i clibrtio hs ow ttied icresigly doit role. It is possible to stisfy qutittively d qulittively icresigly striget specifictios i testig oly through optiized d pled test process i ll developet phses. Oe solutio for optiiztio of the test process with respect to testig depth d icurred costs is pplictio of utoted testig i hrdwre-i-the-loop, softwre-i-the-loop, d odel-i-the-loop siultio. Applictio fesibility of these siultio ethods, however, is ssured oly if the odels eployed feture the required degree of detilig, d ost essetilly if these odels re vilble o tie: i.e., by begiig of the correspodig developet-process phses (for exple, the softwre-testig phse). Without restrictio i gee pplicbility, this presettio will focus o the prticulr spect of testig s i the power tri. The sectio below will begi by describig the pplictio of siultio i the developet process of utootive s. ectio will preset copriso of the HiL, MiL, d il siultio techiques, d will discuss the dvtges d disdvtges of ech. ectio four will elborte i detil o odel geertio s required for such siultio. The pplictio of siultio for utoted testig, i ectio 5, will highlight the reltioship of these techiques to ctul prctice. iultio i developet of utootive s The so-clled V (see fig. ) odel offers good illustrtio of the pplictio of siultio. The type of siultio pplied will deped o the prticulr step of developet. The poit of deprture for developet is the custoer s specifictios, de vilble t the begiig of softwre developet i the for of ctlog of user requireets. The step followig syste specifictio is fuctio specifictio, which c be supported by odel-i-the loop siultio (MiL ). Model-i-the loop siultio tkes plce o PC or worksttio, with siultio of both the specified fuctios s well s the itself. This step fetures developet of the fuctios s softwre odels i grphiclly orieted progrer systes such s MATLAB /iulik. Desig d deteritio of the fuctios the follow i detil. The result is electroic ctlog of specifictios tht c be ipleeted. The followig step etils direct testig d optiiztio of the softwre odels of the fuctios, with the pproprite softwre d hrdwre tools: o bypss coputer i the, or o test bech (i.e., by rpid prototypig ). Model-i-the-loop siultio d rpid prototypig eble fidig d eliitio of specifictio errors i ey phse. oftwre desig d codig for the trget syste i.e., ipleettio of the fuctios i softwre cpble of series productio re icorported i the process steps of progr desig, odule desig,

2 ystespezifiktio syste specifictio fuctiol Fuktiosspezifiktio specifictio odule Moduletwurf desig custoer Kude requireets Aforderug 5 6 clibrtio Appliktio rpid Rpid-Prototypig prototypig Codierug codig Modultest odule test ystetest syste test progr Progretwurf desig itegrtio Itegrtiostest test oftwretwicklugsprozess developet process Model-i-the-Loop iultio iulik- Fhrzeugodell iulik- Fhrzeugodell oftwre-i-the-loop iultio 55 Offlie iultio (DoE) iulik- odel Modell of the der softwre oftwre softwre oftwre series eriecode code iulik- Fhrzeugodell egie iulik- Fhrzeugodell Kefeld- optiistio o ptiierug cotrol Kefelder, preter z.b. chltkefedl d codig. These process steps re idelly ccopied by itesive sttic lyses, i the for of reviews. To icresig degree, dvced utocode geertors re supportig the codig phse. The subsequet odule test, required for verifictio of the odule desig, c be supported by softwre-i-the-loop siultio (il). The softwre odel used eier i odel-i-the-loop siultio is replced here by the lter series code, d is itegrted ito the siultio. The itegrtio test perfored ext is iteded to test the executble progr i iterctio with the other odules, the opertig syste, d the hrdwre copoets used. Durig this phse, hrdwre-i-the-loop siultor (HiL ) supports the egieer. The subsequet fuctio d syste tests re likewise ufesible t the required testig depth without the use of hrdwre-i-theloop siultor. Fig. : iultio i the developet process The ext step clibrtio of the s (i.e., deteritio of the preters d chrcteristic curves) owdys icresigly tkes plce o HiL siultors, by es of offlie siultio (5). HiL siultio, furtherore, hs ssued icresigly essetil role i rig testig d cceptce testig (6). At this poit, for exple, it is possible to siulte the rest of the o egie test beches with trsissio, driver, d drivig resistce i order to be ble to drive e.g. New Europed Drivig Cycles (NEDC). HiL, MiL, d il siultio for testig fuctiol Fuktiostest test Rpid-Cotrol Prototypig cotrol Regelstrecke plt i i the Fhrzeug iulik- odel Modell of the der softwre oftwre teuergerät HiL siultio c be successfully eployed for testig both idividul s well s etworked s. For such purposes, the rel s ust be vilble t lest s prototypes. Fst coputer hrdwre (i.e., the siultio syste) virtully siultes, i rel tie, the relevt copoets of the, the driver, d the eviroet. The HiL syste furtherore offers powerful I/O ports: i order, for exple, to red i the set vlues (ipulted vribles) of the rel vi A/D coverters for the siulted ctutors. The rel geertes these set vlues. I dditio, the HiL syste ust lso offer the required outputs e.g., for pulsewidth-odulted sigls or for D/A coverters i order to eble represe-ttio of sesor vlues for the. Fig. MiL il (PC) il (Processor) HiL depicts the ode-lig depth for HiL, MiL, d il siultio. esors HW-Iterfce Bypss Hrdwre-i-the-Loop iultio iultor teuergerät teuergerät 6 Hil iultio o Prüfstd test bech iulik- Fhrzeugodell iultor Fuctiol oftwre test Prüfstd bech Vehicle Driver urroudigs Actutors HW-Iterfce Opertig yste / Hrdwre Abstrctio Lyer C-Network Fig. : Modelig depth for MiL, HiL, d il siultio Hrdwre oftwre HiL siultio geely ivolves itegrtio ito the siultio loop of uber of rel prts (ctutors d sesors) e.g. throttle-vlve ctutor. Work i fuctio d softwre developet for the power tri is ow icresigly ovig towrd geertio of specifictios i grphicsorieted odelig lguge such s iulik. As result, executble odel of the softwre is provided i very

3 ey phse of the developet process. Oce this softwre odel is copleeted by odels of the ctutor d the sesor systes, it is the possible to siulte the etire syste i MiL. If, i lter step of the developet process, this softwre odel is replced by the coverted code (series code), the result is kow s softwre-i-the loop siultio. iultio the rus etirely o PC, d it is possible to test the code, lso for idividul odules, etirely prt fro itself. iultio-odel repository PC for test egieer iultio coputer Test docuettio eril oitor Developer bord Fig. : Test cofigurtio for il iultio (processor) Fig. depicts dditiol vritio of il siultio []. I cotrst to PCbsed siultio, this vritio ivolves lodig the code oto the trget processor. It is possible to set up PC to iclude ll tools for the build of project-dedicted siultio eviroets, d for coduct d lysis of the tests. The seril oitor llows ccess to the ebedded syste, which is cotrolled vi this oitor. ttus ifortio c be displyed, d the softwre to be tested c be loded. It is ot ecessry for the developet bord to iclude ll the iterfces of the. The seril oitor, however, is bsolutely ecessry s is iterfce for likig to siultio. It is possible, for exple, to ipleet such iterfces vi Etheret or field bus. The siultio-odel repository show here is dtbse syste tht ebles provisio of siultio odules for ulti-project pplictios. Opertio of the siultio process is closely liked to the developet bord: i.e., siultio is tepoly sychroized with the ebedded syste. electio, strt, d teritio of the siultio process tkes plce fro the seril oitor. The test server is used to diister the test docuets tht re utoticlly creted durig testig. A erver provides the testig egieer ccess to the test docuettio for evlutio of the test rus. I dditio, the scripts required for utotio of the tests re filed o this server. Model geertio for MiL, il, d HiL siultio The idel solutio geely ttepted is to use the se odels for MiL, il, d HiL siultio. This solutio, however, requires rel-tie-cpble siultio odels. Owig to the requireet tht HiL siultors should be fster th the s to be tested by fctor of pprox. 0, siultio icreets of pprox. 500 µs will result, for opertios with dvced power-tri s tht hve clock-pulse periods less th 0 s. The odels to be ipleeted ust therefore be so siple s possible i their theticl descriptio but yet ust siulte the dyic behvior of the, with sufficiet ccout tke of ll cotrolled vribles. A coplete odel for the trsissio test, for exple, will coti especilly for utotic coduct of testig, d i dditio to pure siultio of logitudil dyics the followig copoets: driver odel, the possibility of tkig vrious drivig courses d eviroetl coditios ito ccout, s well s possibilities to siulte errors (e.g., trsissio fults). This odel ust be expded to iclude lte dyics for testig of the etwork. I dditio to the iulik syste, orieted s it is to sigl flow, the object-orieted lguge Modelic hs proved effective i this cotext. T M T M T Egie Clutch Trsissio ω ω ω Fig. : Modulr structure of the odel for power tri Vehicle Dyics The odel preseted here ws creted fro the iulik librry VeLoDy, s prt of project executed i collbortio with the Bei copy IAV GbH. With its sub-odels for the egie, clutch, trsissio, d the dyics, this odel siultes the logitudil dyic behvior of the etire power tri. Utiliztio is de here of torque-speed iterfce (see fig. ), whereby the oet blce is distributed to the idividul oduls. The oet origitig fro the egie is

4 successively reduced log the power tri: i.e., by the lod oets of the idividul copoets. Feedbck tkes plce by es of rottiol frequecy, trsferred fro the wheel i the directio of the egie. This torque-speed iterfce kes odulr build of the power tri possible.. Virtul driver [] I order to chieve the gretest possible degree of utotio for testig, virtul driver is required tht c for the purpose of drivig through prescribed test cycles ctivte the ctutors for pedl sesor d brke pedl, thereby observig specifictios for prticulr speed vlue. Idepedetly of the speed regultor, siulted (softwre) s re eployed to ctivte the clutch d the trsissio syste. The specified ger i which the trsissio is to be operted is provided to the trsissio, s fctor of the stipulted speed. The priry criteri of the virtul driver re syptotic behvior i sttiory stte (i.e., costt speed), s well s observce of tolerce rge roud required speed. The virtul driver cosists of the odules for the pedl-sesor cotroller d the brke cotroller, which re switched i plel. The outputs re ctivted vi priority cotroller i ltertive d utully exclusive odes.. Ite-cobustio egies I ost cses for HiL, MiL, d il siultio, cobitios of odel structures re used. Itegrtio of the pheoeologicl descriptio odels copleets the bsic physicl structure. ee fig. 5 for overview of the vrious types of odelig, especilly for siultio of ite-cobustio egies. For siultio of itecobustio egie, rough Dt bsed Theoreticl distictio c be drw betwee the physiclly bsed pproches, d the Blck Box White Box pheoeologicl descriptio by theticl odels of the iput-output behvior o No 0-di. -di. -di. the bsis of observed pretric pretric esureets. I physicl Freqeucy Respose DoE odelig, distictio still tkes Neu Networks plce og the diesios uder cosidertio: three-, Cobied oe-, d zero-diesiol. I the pst, it hs proved Fig. 5: Cobied odel structures for ite-cobustio egies extreely resourcecosuig to obti d preterize such odels purely o the bsis of egieerig d desig dt. Oe chief proble is tht the siultio odels iteiked i such cofigurtios hve for the ost prt ot bee rel-tie cpble. Aother difficulty is tht it is ofte ipossible to cquire the egieerig d desig dt i the tie required. For HiL siultio, oe- d three-diesiol odels re ot suitble owig to the extreely gret out of coputer cpcity d tie required. With zero-diesiol odels [], the egie is broke dow ito copoet sseblies (e.g., cyliders, exhust-gs turbies, etc.), with subsequet deteritio of the respectively predoit sttes. This pproch represets coproise betwee coitet of coputer resources d coputed exctess. I ost cses, zero-diesio odels re cobied with the pheoeologicl odels. Wheres zero-diesiol odel is used for descriptio of the fuel d ir pths (see fig. 6), productio of oet (i.e., the cobustio process) is represeted by pheoeologicl sub-odel. For such odelig, vrious theticl pproch such s grid ps, eurol etworks, d polyoils [].

5 DK E.V. & L,DK p s, V s & & = ugrohrdruck: Mifold pressure ugrohr itke ifold Luftssestro Air flow i the durch itke ds ifold ugrohr : ( & & ) = & L,DK L,Zyl ( & ) L,DK L,Zyl = & V p L,DK dt R T L L, A & L,Zyl fuel pth ir pth ir-fuel ixture torque frictio torque theoreticl odel for itke ifold pressure DoE polyo odel for torque M D = 0 für 70 i 00 i Fig. 6: Cobied odel structures for siultio of ite cobustio egie. Clutch d trsissio syste The trsissio d clutch odels re ech creted s dul-ss systes, cosistig of iput d output shfts. With the id of stte chie, switchig is possible og the possible sttes, d the correspodig solutios for the differetil equtios re clculted. These sttes for the clutch re: ope/slip, d closed. The trsissio hs coprble structure, but with three sttes. Durig orl drivig opertio, whe ger is egged, the stte is orl opertio. If is it ecessry to switch gers, the ger is disegged, d the idle stte is ctivted. Whe the requireet exists to egge ew ger, the syste switches ito the sychroiztio stte. Whe speed equlity is chieved, the syste returs to the orl stge. The effective oets of ierti re the clculted, i ccordce with the ger tht is egged.. Vehicle dyics For clcultios ivolvig dyics, the propulsive power F P is deteried fro the egie oet through the trsissio d the differetil trsissio rtio (i G d i A ). The followig ct i oppositio thereto: the ccelertio force; the drivig resistce, cosistig of rollig (F R ), wid (F W ) d clibig resistce (F C ); s well s the brkig force pplied by the driver (F B ). The followig equtio defies the ccelertio of the : veh & x = F F F F () P W C B 5 Test geet d utoted test processes [5] tests ust be closely liked to softwre developet i defied process (see fig. 7). I order to ehce process relibility (i.e., reproducibility of the results), test-geet syste is essetil. A test-geet syste itegrtes the idividul test-process steps ito oe eviroet, d provides coprehesive ifortio d results. I dditio to cquisitio of the specified requireets d of the test cses, s well s to cretio of the test pl, geet syste ebles iititio of the utoted test d its evlutio vi the pproprite iterfces. For the bove resos, ll the copoets of siultio syste ust be reote-cotrollble: begiig with the siultor d extedig to the tble clcultio progr tht produces the test docuettio. cript lguges such s TcL/Tk d Pytho hve becoe extesively ccepted for this purpose. The

6 tools used for specifictio of the tests ow icresigly support utotic geertio of the scripts. For exple, utotio progrs re creted i Pytho fro UML sequece digr. The error dtbse, likewise itegrted i test geet, docuets the results of ll testig cses: e.g., s either with or without errors. The geet syste records test coditios s exctly s possible, i order to be ble to reproduce y errors tht occur. A essetil poit fter ech test cycle is deteritio of the degree of turity of the softwre. I this process, copriso is ecessry of the specified requireets with the extet to which they hve bee covered by successfully coducted test rus, icludig the reiig errors. A record of the course of errors d of test results is lso essetil prt of test geet. Fig 7: Test process 6 ury d outlook This presettio provides overview d descriptio of the possibilities offered by siultio for the testig of utootive s. Elbortio is de of the siultio ethods MiL, il, d HiL, d of the ethods for obtiig rel-tie-cpble odels for siultio of the logitudil dyics of. Future developets will revel the extet to which tests will lso be perfored with il siultio tht re ow ruig predoitly o HiL siultio systes. A test-geet syste is the idel pltfor for siultio of the etire test process. The itegrtio of utoted tests for MiL, il, d HiL siultors, s well s geet of the odels required for odel-supported tests, will i this cotext gi i iportce i the future for work i the re of utoobile electroics. Refereces [] Mibu, O.; Rebeschieß,.: Test vo dptive oftwreechise zur Fehlerkopestio. iultio ud Test i der Fuktios- ud oftwreetwicklug für die Autoobilelektroik. Hus der Techik (HdT) Tgug,./ 5. März 005 (ccepted). [] Heidrich, I: iultio ud Optiierug eies Kurbelwellestrtergeertortriebstrgs it Motor ud Getriebekupplug. TU Bei, Diplorbeit FG Elektroische Mess- ud Digosetechik, 00 [] Offer, T.; Hätschel, U.: Virtuelle Etwicklug ud Test vo teuergerätefuktioe i dyische Fhrzeugbetrieb. I teuerug ud Regelug vo Fhrzeuge ud Motore AUTOREG 00, Mhei, 5. u. 6. April 00. VDI/VDE [] Güh, C.; Röpke, K.; Lide, M.: Gewiug echtzeitfähiger Modelle für die Hrdwre-ithe-Loop iultio it Hilfe der sttistische Versuchsplug. VDI yposiu Mess- ud Versuchstechik i Fhrzeugbu. VDI-Berichte Nr. 66, 00 [5] Edt, P.; Reihold, A.; Mitzlff, D.: Testgeet ls Itegrtiosplttfor für Testufgbe ud Testwerkzeuge i der Autoobilelektroik. Ifotiet / Teletik i Fhrzeug, , expert veg 00 [6] Broek, B; E. Noteboo; E.: Testig Ebedded oftwre. Addiso-Wesley, 00.