1. 1 of 25 June 4, 2002 Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi Department of Computer and Information Science Linköpings universitet

2. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 2 of 25 June 4, 2002 Contributions Defined a simple architecture definition language (ADL) Used to model the automotive electronic systems XML representation: models portable among manufacturers and suppliers Identified the constraints of the automotive electronic field Types of requirements Modelling and representation of automotive electronic requirements using XML technologies Xlinkit, XQuery, CommonRules Case study representing a vehicle cruise controller Modeled using our ADL The requirements placed on the cruise controller have been modelled using xlinkit, XQuery and CommonRules

3. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 3 of 25 June 4, 2002 Outline nAutomotive Electronics The Industry Generic Architectures The Cruise Controller nModelling AE using XML The Merits of XML The Cruise Controller Model The Cruise Controller nRequirements Modelling Requirements on the Cruise Controller XML Technologies Xlinkit, XQuery, CommonRules n Conclusions and Future Work

4. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 4 of 25 June 4, 2002 Embedded Systems Automotive Electronic Systems  Complex distributed embedded systems that have important requirements safety cost, and performance.  Responsible for controlling the functionality of a vehicle.

5. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 5 of 25 June 4, 2002 Automotive Industry: Interoperability XML Car makers Suppliers

6. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 6 of 25 June 4, 2002  An ADL is a language that provides features for modeling a hardware and software system’s conceptual architecture.  In other way, it is a high-level description of the overall interconnection structure of an architecture.  It provides formal modeling notations for architectural elements, such as components, connectors.  It also provides development tools that operate on architectural specifications, such as configuration and constraints.  It reduces cost of development.  ADLs: Software: ACME,Rapide, C2, Darwin, MetaH, SADL, UinCon, Wright, xArch, … Hardware: MoML, ISDL, Valen-C, MIMOLA, LISA, nML, ARC, Axys, RADL, Target, MDES, EPRESSION, … What is an ADL?

7. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 7 of 25 June 4, 2002 ADL Exchange: The Merit of XML XML highly suited for ADLs “The Merit of XML as an Architecture Description Metalanguage”, Steve Pruitt et al. Representation Analysis Traceability Views Collaboration Repository

8. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 8 of 25 June 4, 2002 AE: Generic Architecture

9. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 9 of 25 June 4, 2002 Cruise Controller Vehicle cruise controller. Modelled with a CPG of 32 processes and two conditions. Mapped on 5 nodes: CEM, ABS, ETM, ECM, TCM. Schedule: Process Start WCET Resource PR1 0 0 P6 PR2 0 12 P1 PR28 0 12 P2 ARC2 12 1 B1 PR3 13 7 P2......

10. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 10 of 25 June 4, 2002 XML Model for Cruise Controller  architecture.xml I 128  behaviour.xml 7 2 PR3 PR4 0  mapping.xml PR1 PR2 PR30  schedule.xml 0 0 P6 0 12 P1

11. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 11 of 25 June 4, 2002 Requirements Engineering  RE is the branch of systems engineering concerned with  the real-world goals and constraints on systems  the relationship of these factors to precise specifications of systems behavior, and to their evolution over time and across system families.  RE Activities:  eliciting requirements  modeling and analyzing requirements  communicating requirements  agreeing requirements  evolving requirements

12. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 12 of 25 June 4, 2002 Requirements on the Cruise Controller  Requirements on the model  The model should be consistent  Every process should be mapped to one and only one node  Every sensor/actuator should be connected  The schedule should be correct  The schedule should respect the precedence constraints  No two slots in the schedule should overlap  Cruise Controller  Timing requirements  The CC should execute within 100 ms  Resource requirements  The sum of processes’ memory on a node should not exceed that node's capacity  Should be expressed using XML Technologies

13. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 13 of 25 June 4, 2002 XQuery: An XML Query Language  W3C standard  http://www.w3.org/TR/xquery  Derived from Quilt Jonathan Robie, Don Chamberlin, and Daniela Florescu  Based on XML-QL  Relevant W3C documents  XML Query Requirements  XML Query Use Cases  XQuery 1.0: An XML Query Language  XQuery 1.0 and XPath 2.0 Data Model  XQuery 1.0 Formal Semantics  XML Syntax for XQuery 1.0 (XQueryX)

14. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 14 of 25 June 4, 2002 XQuery  To find all process names and connected sensors for processes whose worst case execution time > 10ms & memory size < 20MB. { for $b in document(“Behavior.xml”)//Process where $b/WCET > 10 and $b/Memory < 20 return { $b/Sensor }  Overview  Path expressions: XPath  Conditional expressions  FLWR (“flower”) expressions

15. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 15 of 25 June 4, 2002 XPath Behavioral_Model Process NameWCETMemory Sensor PR2 12 ms 10 KBCC  W3C Standard  http://www.w3.org/TR/xpath http://www.w3.org/TR/xpath  Example 1: Behavioral_Model/Process/Name  Example 2: Behavioral_Model/Process/Name [../WCET = 12] Tree Construction

16. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 16 of 25 June 4, 2002 FLWR (“FLOWER”) Expression  “Flower” expressions FOR... LET... FOR... LET... WHERE... RETURN... FOR/LET Clauses WHERE Clause RETURN Clause List of tuples Filtered list of tuples Instance of XQuery data model Example: find all Processes with WCET > 14 FOR $x IN document("behavior.xml") // Process WHERE $x/WCET > 14 RETURN $x/@Id Result: PR6 PR8 PR31

17. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 17 of 25 June 4, 2002 If-Then-Else { let $a := document("data/schedule.xml")//SLOT, $b := max(for $c in document("data/schedule.xml")//SLOT/Start return int(string-value($c))), $d := $a[Start = $b], $e := $a[Start = $b]/Start, $f := $a[Start = $b]/Duration, $g := $b+$f return { $e, $f} { {$g}, if ($g>100) then Time Lapsed else "WCET ok" } } The CC should execute within 100 ms.

18. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 18 of 25 June 4, 2002 Resource Requirement Query for $map in document("data/sweb/mapping.xml")//MAP, $nod in document("data/sweb/architecture.xml")//:NODE[@Id = $map/@Resource] let $proc := document("data/sweb/behaviour.xml")//PROCESS[@Id = $map/Process] return <processor Name={$nod/@Name} Id={$nod/@Id} HasMemory={$nod/Memory/text(),$nod/Memory/@unit} MemoryUsedByScheduledProcesses={sum($proc/Memory),$nod/Memory/@unit}> { for $process in $proc return <process Name={$process/@Name} Id={$process/@Id} Memory={$process/Memory/text(),$process/Memory/@unit} /> sortby(int(substring-before(@Memory,"K"))) } sortby(int(substring-after(@Id,"P")))

19. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 19 of 25 June 4, 2002 Resource Requirements Result query result:check_resource_consistency.xml …

20. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 20 of 25 June 4, 2002 XQuery Software  QuiP  http://www.softwareag.com/ developer/downloads/default.htm  Software AG  Windows and Linux on x86  Features  Latest W3C syntax  Graphical user interface.  Kweelt  http://kweelt.sourceforge.net/  Open Source  Runs on all Java platforms  Problems  Older syntax, from previous W3C requirements.  No graphical user interface.

21. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 21 of 25 June 4, 2002 xLinkit  Xlinkit is a lightweight application service which provides rule- based link generation and checks the consistency of distributed documents and web content.  xLinkit is specially designed to validate complex documents  Semantics: first order logic Document Set Links Link Generation Docunments Rule Language XML Rule Set Rule Engine Architecture XLink Rules

22. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 22 of 25 June 4, 2002 Query Construction

23. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 23 of 25 June 4, 2002 Xlinkit Results consistent <xlinkit:ConsistencyLink ruleid="http://www.ida.liu.se/rule.xml#/ consistencyruleset/consistencyrule[1]"> inconsistent

24. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 24 of 25 June 4, 2002 Discussion  XML technologies  Current technologies  Xlinkit: first order logic + path expressions  XQuery: relational databases + path expressions  CommonRules: logic programming  Semantic Web  DAML+OIL  RuleML

25. Portable Automotive Electronic Models using Standard XML Technologies Syed Zia Akbar Zaidi 25 of 25 June 4, 2002 Conclusions and Future Work Simple architecture ADL with an XML representation Modelled the cruise controller using this ADL Automotive electronic requirements Modelling and representation of requirements using XML technologies Xlinkit, XQuery, CommonRules Requirements on the cruise controller Modelled using xlinkit, XQuery and CommonRules Future work: What is the advantage of using the SemanticWeb technologies? DAML+OIL instead of XML for the ADL representation RuleML instead of CommonRules