Hard Real-time Embedded Systems are ubiquitously used today in safety critical commercial applications

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1 Extenble and Scalable Tme Trggered Schedulng or Automotve Applcaton We Zheng Advor: Proeor Alberto Sangovann-Vncentell Che Revew Ma Berele CA Agenda Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Problem Problem Model Model Mathematcal Mathematcal Model Model Algorthm Implementaton Implementaton Evaluaton Evaluaton Che Revew Ma

2 Proect Motvaton Hard Real-tme Embedded Stem are ubqutoul ued toda n aet crtcal commercal applcaton X-b-wre Power Tranmon Unt - 6-lne per da ppm redental deect - 5 month valdaton tme FABIO ROMEO Magnet- Marell DAC La Vega June 20th 2001 Vercaton o complex tem tme and reource ntenve For at tme-to-maret Extenble and Scalable tem Che Revew Ma Degn Flow Functonalt Archtecture Control algorthm degn Plant Model degn Fault Model Functonal Smulaton Functonal Model Phcal Archtecture Model ECU archtecture Networ archtecture Allocate Functon to Ta Ta and ther WCET Sgnal Mddleware OS Sotware Model Allocatng ta to ECU Allocatng gnal to BUS Mappng Renement Vrtual Prototpe Schedulng Smulaton capturng computatonal contrant TT behavoral mulaton Che Revew Ma

3 Functonalt: Allocate Functon to Ta TASK A TASK A INPUT PROCESSING TASK B DISTRIBUTED CONTROL AGREEMENT TASK D OUTPUT FAULT MANAGEMENT INPUT FAULT MANAGEMENT OUTPUT PROCESSING SYSTEM COORDINATION BY-WIRE CONTROL TASK C NODE STATE OF HEALTH SOURCE: GM Che Revew Ma Stem Archtecture ECU APP. TT TASKS FT. TT APP. OSEK TASKS TASKS OSEK TIME DISPATCHER... OSEK SCHEDULER Comm. controller BUS DRIVER BUS DRIVER... STATIC SEG COMMUNICATION CYCLE NIT SYMBOL WIN DYNAMIC SEG Che Revew Ma

4 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Problem Statement Ident a et o metrc to capture extenblt and calablt Appl the et o metrc n a degn Evaluate the eectvene o the et o metrc Speccall we want to: Stud a hard real tme embedded tem n the automotve doman Focu on the chedulng apect o tem degn Characterze extenblt and calablt n chedulng Appl the et o metrc n a chedulng algorthm Evaluate the eectvene o the approach wth ndutral cae tud Problem Problem Ident a Set o Metrc Formall Decrbe Metrc Appl Metrc To Degn Evaluate Reult w.r.t. Metrc Che Revew Ma

5 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Prevou Wor Statc cclc chedulng ha been extenvel reearched Clacal chedulng theor ue metrc uch a Mnmzng um o completon tme Mnmzng chedule length Mnmzng reource For real tme tem deadlne added a a contrant Empha hted to ndng eable oluton whle Mnmzng end-to-end dela Mnmzng communcaton cot Cloet problem concept come rom Paul Pop et al Cloet problem ormulaton come rom Armn Bender et al Che Revew Ma

6 Prevou Wor Paul Pop et al wrote about ncremental degn Ue lt chedulng approach to obtan a vald chedule Ue a heurtc to dtrbute lac n the tem Mng everal mportant component Preempton not condered Reultng chedule not utable or uture ta wth urgent deadlne Meage lac not dtrbuted Extenblt not condered Armn Bender et al ued mathematcal programmng or mappng and chedulng Wor motvated b otware-hardware co-degn Obectve to obtan chedule eablt whle Maxmzng Perormance Mnmzng reource Che Revew Ma Reearch Drecton Idle Tme Idle[ ECU1 T5_2] T1_1 T3 T5_1 T1_2 T5_2 ECU1 ECU2 T2_1 T4 T2_2 D 12_1 D 34 D 12_2 Bu Tme Data Slac Slac[ D12_2 T2_2] Focu on optmall utlze redundance n chedule or extenblt and calablt Idle tme and lac are tradtonall ncorporated n hard real tme embedded tem chedule to ncreae tem robutne We hould utlze thee redundance to: Tolerate ncremental degn change Accommodate new ta to be added n uture product update Che Revew Ma

7 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Capture the Metrc Model Model Extenblt Tolerate change o Ta WCET Tolerate change o Data WCTT Motvaton Scalablt Accommodate NEW ta b tatcall chedulng them on a legac tem Mantan Bu Schedule Mantan non-nvolved ECU chedule Mantan nvolved ECU chedule wthout reconguraton Meage let & Rght lac Max Sum o all lac Mn Varance o all lac Implementaton Approach Provde bloc o computaton tme or uture computaton ntenve ta Provde porot n chedule to allow or uture ta wth tght deadlne ECU dle tme dtrbuton Bu dle tme dtrbuton Evenl dtrbute all dle tme Che Revew Ma

8 Applng the Metrc Mathematcal Mathematcal Model Model Develop a ormal repreentaton o the problem ung mathematcal programmng and olve t ung extng olver Modelng Language: AMPL Advantage: obtan optmal oluton w.r.t. cot uncton Dadvantage: computatonall ntenve utable onl or moderatel zed problem Aumpton: Hard real tme deadlne Statcall cheduled ta wth data dependenc Dtrbuted and heterogeneou mult-proceor archtecture Tme trggered bu wth TDMA protocol Preempton allowed on ECU wth no level lmt Mult-rate ta upport wth adaptve ta graph expanon Fxed ta allocaton wth no ta mgraton Che Revew Ma Mathematcal Formulaton 1 Mathematcal Mathematcal Model Model Notaton The et o Ta T = { t = 1... m} The et o ECU E = { e = 1... n} The et o ta par wth data dependenc runnng on the ame ECU σ = {( t t t T t T t < t a = a } The et o ta par wth data dependenc runnng on derent ECU ϖ = {( t t t T t T t < t a a 1} The et o ta non-reachable ta par runnng on the ame ECU = {( t t t T t T a = a t <> t } The et o ta par runnng on the ame ECU π = {( t t t T t T a = a E} The et o ta allocaton or ECU λ { κ E} κ = { t a = 1} = Che Revew Ma

9 Mathematcal Formulaton 2 Mathematcal Mathematcal Model Model Parameter and Varable Mappng rom Ta to ECU M = T E = { a = 1... m; = 1... n} 1 ta mapped to ECU a = 0 otherwe Ta and Meage Ta: 6-tuple parameter varable Vector e T r T p T c T T T τ : e r p c WCET Releae Tme Perod Idle tme Startng tme Fnhng tme Meage: 5-tuple parameter varable Vector ς : mt l r m m mt ( ϖ WCTT l ( ϖ Let Slac rl ( ϖ Rght Slac m ( ϖ Startng tme m ( ϖ Fnhng tme Che Revew Ma Mathematcal Formulaton 3 Mathematcal Mathematcal Model Model Parameter and Varable (contnue Idle tme and Integer Varable c dle rt c ater lat c 0 = 1 Idle tme or ta not the rt ta n o t runnng ECU Frt dle tme or each ECU Idle tme or ECU beore the uper perod the tartng tme o ta precede the tartng tme o ta otherwe ( p z l 0 = 1 0 = 1 ta not preempted b ta otherwe data tranmtted rom ta to ta precede data tranmtted rom ta to l otherwe ( ( ϖ ( l ϖ Che Revew Ma

10 Che Revew Ma Mathematcal Formulaton 4 Subect to the ollowng contrant: Releae and Deadlne Contrant Executon Tme/Tranmon Contrant Precedence Contrant Non-negatve and Integer Contrant T d T r T T e p e = ( σ ( <= ϖ ( m ϖ ( mt m ϖ = ( m mt m = Λ Λ ( 1( ( (1 ( l or l bnar z bnar p m m T l = = ( ( ( 0( ϖ ϖ ϖ Mathematcal Model Mathematcal Model Che Revew Ma Mathematcal Formulaton 5 Contrant (contnued: Mutual excluon contrant Idle tme contrant n m or n m z m mt m n m or n m z m mt m m n m n m n m n m n Λ Λ ( ( (1 ( ( ϖ ϖ ϖ ϖ Λ Λ Λ Λ ( 1 ( 1( ( (1 ( p p p p p E e P c c E P c p c c p c lat ater dle lat ater dle dle dle = Λ Λ Λ Λ Λ ( (1 0 ( ( ( κ κ κ π π π Mathematcal Model Mathematcal Model

11 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Multple Obectve Cot Functon Algorthm Extenblt max R = ( ϖ (( m ( m Scalablt mns = a E T dle 2 ater _ lat 2 ( c average ( c average E Jontl Extenblt & Scalablt mn RS K ( R K S = 1 2 Che Revew Ma

12 Extenblt and Scalablt o Tme Trggered Schedulng Algorthm Mappng T1 T5 T2 ECU1 ECU2 T1 T3 T5 T2 T1 T2 T5 T4 T3 T4 T6 FlexRa Ta graph expanon (n a SUPERperod unctonalt archtecture Mnmze Scalable Checng Schedule End Schedulablt Extenble Schedule to End Latenc T1_1 T3 T1_1 T5_1 T3 T3 T5_1 T1_2 T5_1 T1_2 T5_2 Jontl Conderng ECU1 T1_1 Extenble T3 and Scalable T5_1 T1_2 T5_2 ECU1 ECU1 T2_1 T4 T1_1 T3 T2_1 T5_1 T1_2 T4 T4 T2_2 T2_2 ECU2 T2_1 T4 ECU1 ECU2 ECU2 D 12_1 D 34 D 12_2 D 12_1 D 34 D 34 T2_1 D 12_2 T4 T5_2 T2_2 T5_2 T2_2 Bu Bu D 12_1 D 34 D 12_2 ECU2 Bu Tme Tme 0 D 12_1 1 D 34 2 D 12_2 3 4 Tme Bu Extenble Scalable Schedule: Tme Schedule--- 0 Add 1 2 WCET Increae 3 4 WCET New Ta Change T1_1 T3 T3 T5_1 T5_1 T1_2 T5_2 T1_2 T6 T5_2 ECU1 T2_1 T2_1 T4 T4 T2_2 T2_2 ECU2 D 12_1 D 12_1 D 34 D 34 D 12_2 D 12_2 Bu Tme Che Revew 4 Ma T2_2 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Summar Concluon Future Wor Che Revew Ma

13 Advanced Automotve Control Applcaton Obect Dtance and Speed Current Speed T9 T7 T8 Dered Speed T10 Current throttle Dered brang poton orce Dered Throttle poton Adaptve Crue Control T11 T13 T12 T14 Actuate Throttle Actuate brae T15 T16 T17 T18 Let-Rear Let-Front Rght-Rear Rght-Front Wheel peed Wheel Speed Wheel Speed Wheel Speed Hand-wheel Lateral Yaw Rate poton acceleraton Dered Brang Force Actuate Actuate Brae Throttle Tracton Control T19 T23 T20 T22 T21 T24 Hand-wheel Road-wheel poton orce Dered road- Dered hand- Wheel angle Wheel eort Electrc Power Steerng T3 T1 T4 T2 Actuate teerng Rac motor Force eedbac To drver T5 T6 Applcaton and correpondng ta graph repreentaton Che Revew Ma Archtecture and Ta Allocaton P1 T4T11 P2 T3T12 T22 P3 T10T20 Proceor wth ta allocated Throttle poton Steerng Rac Force Obect Dtance Actuator are drectl connected to the bu Throttle Value Hand- Wheel motor Steerng Rac Motor FlexRa LR Wheel peed LF Wheel Speed RR Wheel Speed RF Wheel Speed Car Speed Accelarator Hand- Wheel angle Brae Senor are drectl connected c to the bu Che Revew Ma

14 Implementaton Inratructure Implementaton Implementaton Cae tud Decrbe the Metrc Automatc AMPL data le generaton AMPL model wth cot uncton and contrant Formalze the Metrc CPLEX olver. Automatc Gant graph generaton T1_1 T3 T5_1 T1_2T5_2 ECU1 T2_1 T4 T2_2 ECU2 D 12_1 D 34 D 12_2 Bu Tme Sel-developed proect nratructure. O-the-hel proect nratructure Get Schedulng Reult Evaluate Reult w.r.t. Metrc Che Revew Ma Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Summar Concluon Future Wor Che Revew Ma

15 Cot Functon Evaluaton Evaluaton Evaluaton Mult-obectve cot uncton an abtracton Mathematcal programmng ormulaton ha lmted emantc Extenblt and calablt metrc are too complex Decrbed n ull the cot uncton would be too computatonall expenve Mut determne the cot uncton abtracton eectvel repreent the metrc Ue the reult o CPLEX olver Extract real lac and dle tme dtrbuton baed on prece denton o the metrc Compare reult wth the chedule wthout extenblt and calablt optmzaton Che Revew Ma Tradtonal Schedulng Reult Evaluaton Evaluaton Optmzng or End to End Latenc Che Revew Ma

16 Optmzed Schedulng Reult Evaluaton Evaluaton Optmzng or Extenblt and Scalablt Che Revew Ma Metrc Evaluaton Evaluaton Evaluaton Our et o metrc one abtracton o the extenblt and calablt concept Mut determne our metrc eectvel handle ncremental degn change Incremental Degn Scenaro: Bac ACC Stop-N-Go ACC Addton o a new Adaptve Crue Control eature Predct dered peed baed on: Dgtal map normaton Forward loong von enor Requre addton o ta and meage Some extng ta wll need more computaton tme Che Revew Ma

17 Adaptve Crue Control Evaluaton Evaluaton Incremental Degn Change: Add new Dgtal Map Computaton ta on P1 More complex algorthm n T10 (Dered Speed Control Dered Speed Control requre new nput rom Hand Wheel Senor Dered Throttle Control requre new nput rom Forward Von Senor Dgtal Map Computaton Hand Wheel Poton Obect Dtance Current Speed and Speed T19 T_add T9 T7 T8 Dered Speed Current throttle poton Dered Throttle poton Dered brang orce T11 T10 T12 Actuate Throttle Actuate brae T13 T14 Che Revew Ma Tradtonal Schedule Evaluaton Evaluaton In Tradton Schedule: Incremental change mpoble wthout ull rechedulng Che Revew Ma

18 Optmzed Schedule Evaluaton Evaluaton In Tradton Schedule: Incremental change mpoble wthout ull rechedulng In Optmzed Schedule: A lot more porot to accommodate new ta and meage Che Revew Ma Optmzed Schedule Evaluaton Evaluaton In Tradton Schedule: Incremental change mpoble wthout ull rechedulng In Optmzed Schedule: A lot more porot to accommodate new ta and meage New uncton added: Wthout dturbng legac chedule Che Revew Ma

19 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Concluon Succeull captured extenblt and calablt metrc Recognzed mplcaton n acceleratng tme-to-maret o embedded tem development Reduce re-vercaton burden n ncremental degn low No ncreae n reource requrement Formulated the chedulng problem a a mathematcal programmng problem Contructed mult-obect cot uncton abtracted rom the metrc The cot uncton hown to be eectve or the metrc The metrc hown to be eectve n ndutr cae tud Che Revew Ma

20 Agenda Proect Motvaton Problem Statement Prevou Wor Invetgatve Approach Metrc Denton Mathematcal Formulaton Mult-Obectve Cot Functon Cae Stud Stem Decrpton Cot Functon Evaluaton Metrc Evaluaton Concluon Future Wor Che Revew Ma Future Wor Protocol Comparon FlexRa V. TTP Slot Sze Optmzaton Slot Sze Exploraton COMMUNICATION CYCLE Read/Wrte Meage Frame Pacng Buer Requrement COMMUNICATION CYCLE Fragmentaton Che Revew Ma

21 Future Wor Control algorthm degn Plant Model degn Fault Model Functonal Smulaton Ta and ther WCET Sgnal Mddleware OS Functonalt Functonal Model Sotware Model Allocate Functon to Ta Archtecture Phcal Archtecture Model ECU archtecture Networ archtecture Renement Allocatng ta to ECU Allocatng gnal to BUS Vrtual Prototpe Mappng Schedulng Tme Trggered Schedulng Meage Schedulng Ta Schedulng Smulaton capturng computatonal contrant TT behavoral mulaton Slot Sze Optmzaton Che Revew Ma Reerence Paul Pop: Anal and Snthe o Communcaton-Intenve Heterogeneou Real-Tme Stem. Ph. D. The No. 833 Dept. o Computer and Inormaton Scence Lnöpng Unvert June 2003 H. Kopetz et al. Real-Tme Stem-Degn Prncple or Dtrbuted Embedded Applcaton Kluwer Academc Publher 1997 N. Kandaam J. P. Hae B. T. Murra. Dependable Communcaton Snthe or Dtrbuted Embedded Stem. Lu Laland Schedulng Algorthm or Multprogrammng n a Hard-Real-Tme Envronment J. ACM 20 p Devller Gooen Lu and Laland chedulablt tet revted Inormaton Proceng Letter p Bn Go. Buttazzo Gu. Buttazzo Rate Monotonc Anal : The Hperbolc Bound p Pradumna K. Mhra and Saneev M. Na. Dtrbuted Control Stem Development or FlexRa-Baed Stem A. Bender Degn o an Optmal Looel Coupled Heterogeneou Multproceor Stem n Proceedng o Electronc Degn and Tet Conerence page Che Revew Ma