The Timing Model TIMMO Methodology Guest Lecture at Chalmers - PDF document

ITEA 2 – 06005: TIMMO Timing Model The Timing Model TIMMO Methodology Guest Lecture at Chalmers University Stefan Kuntz, Continental Automotive GmbH 10-02-2009 TIMMO Methodology Page 1 Welcome About Stefan Kuntz • Studied Electrical Engineering (HW) und Computer Engineering (SW) • Over 20 years experience in the software engineering domain in different positions and industries (mainly embedded distributed real-time systems) • Worked in Italy and the United States • Companies – Corporations (Siemens AG, SGS Thomson) – SMEs (FORCE Computers, MEDAG) – Start-Up • Today at Continental Automotive in the Innovation Center of the division Powertrain Engine Systems – Modeling, Design and Implementation of Software intensive Systems (SiS) – Active member of AUTOSAR Timing Subgroup – TIMMO work package 3 "Methodology" leader – Research projects: mobilSOFT, TIMMO, Automotive Core 2020 10-02-2009 TIMMO Methodology Page 2 1

Warm-UP Some questions • Why does one need methodology and methods respectively? • Ever heard about processes and methods before? • Who already did apply methods consciously? • Do you know why methodology is important? • What is architecture? Domain knowledge, notation, and methods. • What are your expectations? Please, ask questions whenever you like! 10-02-2009 TIMMO Methodology Page 3 Agenda • Introduction to TIMMO • Overview of EAST ADL • TIMMO Events and Event Chains • Example • Questions and Discussion 10-02-2009 TIMMO Methodology Page 4 2

Introduction to TIMMO Funded Project • Timing Model TIMMO • Funded by Information Technology for European Advancement ITEA • Duration: April 2007 to September 2009 • Partners – AUDI AEV, Volkswagen carmeq, Volvo Technology – BOSCH, Continental Automotive, DENSO Automotive, ZF Friedrichshafen – ETAS, Mentor Graphics Sweden, Siemens Information Systems, SYMTA VISION, TTTech – Chalmers University, C-Lab, University of Paderborn 10-02-2009 TIMMO Methodology Page 5 Introduction to TIMMO Objectives • Solving the problem of describing the temporal/timing requirements and behavior of a distributed real-time embedded systems (DRES) • Define a language to specify – timing requirements and constraints – timing properties • Provide the capability to analyze and assess timing, a.k.a. temporal behavior, of a system beginning at early stages of the development process • Define a methodology that enable one to apply the language in different scenarios • Alignment with Aut omotive O pen S ystem Ar chitecture AUTOSAR 10-02-2009 TIMMO Methodology Page 6 3

Introduction to TIMMO Objectives of TIMMO and AUTOSAR Timing Subgroup • Timing Model TIMMO – Methodology. Formal and standardized specification, analysis, and verification of timing properties and constraints across all development phases. – Language. Formal and standardized specification, analysis, and verification of timing properties and constraints on all levels of abstraction. – Early validation. Improved, predictable development cycle. • AUTOSAR WP II 1.2 Timing Subgroup (Release 4.0) – Augmenting AUTOSAR with timing properties for the analysis of a system’s dynamics – Augmenting AUTOSAR with timing constraints for the validation of a system’s dynamics – Consolidated and consistent representation of timing information – Integration of feedback from ITEA 2 project TIMMO 10-02-2009 TIMMO Methodology Page 7 Introduction to TIMMO Timing and Abstraction Levels (EAST ADL) OEM – «Requirement» The doors shall be unlocked not later than 1 second after a valid [transponder] key has Feature Level been recognized. EAST ADL Analysis Level «Requirement» ... EAST ADL ? How are timing requirements broken down into timing Design Level properties; and how are timing properties transformed EAST ADL into timing constraints and requirements respectively? «Property» ... Implementation Level AUTOSAR Operational Level Supplier – «Property» The function (runnable) AUTOSAR unlockDoor responds within 120 ms (nominal) to a request to unlock the doors. [Assumption: The function is executed on a X12 6MHz processor ... ] EAST Electronics Architecture and Software Technology ADL Architecture Description Language 10-02-2009 TIMMO Methodology Page 8 4

Introduction to TIMMO Reflections on Timing Requirements and Properties OEM – «Requirement» The doors shall be unlocked not later than 1 second after a valid [transponder] key has been Feature recognized. Level (EAST ADL) «Requirement», Analysis «Property» ... Level (EAST ADL) ? Design How are timing constraints broken down into timing constraints/properties; and how are timing properties Level (EAST ADL) transformed into timing constraints/properties? Implementation «Property», Level (AUTOSAR) «Requirement» ... Operational Supplier – «Property» The function (runnable) unlockDoor Level (AUTOSAR) responds within 120 ms (nominal) to a request to unlock the doors. [Assumption: The function is executed on a X12 6MHz processor ... ] Level of abstraction 10-02-2009 TIMMO Methodology Page 9 Overview of EAST ADL EAST ADL Abstraction Levels Functional View Feature This level describes the features visible to the user such as windscreen wipers, window lifter, cruise control. Level Analysis This level captures the behavior and algorithms of the vehicle functions and their inter-dependencies. Level Design This level represents the decomposition of the functionality analyzed in the Analysis View and its design. Level Implementation This level represents the logical software architecture, the technical architecture, and consists of the OS and middleware models. Level Operational This level describes the mapping of the software components and the executable system including the binary code and [parameter] data. Level Software and Hardware View Level of abstraction 10-02-2009 TIMMO Methodology Page 10 5

Overview of EAST ADL EAST ADL Abstraction Levels and AUTOSAR Views Functional View Feature Feature Model Level Analysis Functional Analysis Level Architecture/Model Hardware Design Design Architecture/Model Functional Design Middleware Level Architecture/Model Abstraction Environment Models Implementation Implementation Architecture/Model ECU Resource Level AUTOSAR VFB, System, and ECU view Descriptions Operational Operational Architecture/Model Level AUTOSAR ... Software and Hardware View Level of abstraction Artifacts 10-02-2009 TIMMO Methodology Page 11 TIMMO EAST ADL Abstraction Levels, Events, and Timing Events are refined across the Event Feature Transformation from levels of abstraction. An event on Level continuous time into one level may be refined into a discrete time sequence of events (causality) on domain. Analysis the level of abstraction beneath. Level Event models (periodic, sporadic, pattern, arbitrary) are specified for Design events. Level Transformation from EAST ADL Design On the operational level all events Level to AUTOSAR given on the implementation level Implementation views [Timing]. occur over time. Level Operational Level Event Occurrences time 10-02-2009 TIMMO Methodology Page 12 6

TIMMO Event Models • Periodic event model • Sporadic event model • Pattern event model • Arbitrary event model 10-02-2009 TIMMO Methodology Page 13 TIMMO Periodic Event Model 10-02-2009 TIMMO Methodology Page 14 7

TIMMO Sporadic Event Model 10-02-2009 TIMMO Methodology Page 15 TIMMO Pattern Event Model 0 60 Crankshaft Camshaft • Observable events: Start of crankshaft (position 0°), Top-Dead-Center of cylinders/piston (TDC1, TDC2, ...) Bottom-Dead-Center of cylinders (BDC1,BDC2, ...), Start of segment and half-segment of cylinders, open inlet valve, close inlet valve, open outlet valve, close outlet valve, etc. 10-02-2009 TIMMO Methodology Page 16 8

TIMMO Arbitrary Event Model 10-02-2009 TIMMO Methodology Page 17 TIMMO Event Chains Stimulus Response • Relating events • Causality EC Response/Stimulus ECS ECS ECS ECS ECS ECS EC Event Chain ECS Event Chain Segment 10-02-2009 TIMMO Methodology Page 18 9

TIMMO Example: Braking System (High Level System View) Brake/Stop Brake Pedal Lights Brake/Stop Brake System Light Rear Right Other Brake/Stop Traffic The Driver Light Rear Left Participant From the actor/user's (driver, other From a vehicle's point of view the traffic participants) perspective the Brake System simply is a box without brake system consists of a brake pedal any input/output arrows. So what is the (sensor) and the stop lights relation with other vehicle functions? (actuators). An assumption is that the For example, the vehicle function brake actuators are part of the system Cruise Control also senses the brake called 'Brake System' but are not pedal in order to temporarily turn off its shown in the figure depicted above, due to the fact that these actuators are operation when the driver pedals the not directly visible to actors (driver and brake pedal. In this case the brake traffic participants). pedal becomes a global visibility in the vehicle's system. 10-02-2009 TIMMO Methodology Page 19 TIMMO Example: Braking System (The Hardware View) 1 1 3 3 2 4 3 3 1 1 Network, e.g. CANbus, FlexRay TM 1 Brake Actuator 2 Pedal Module – Brake Pedal 3 Wheel Speed Sensor 4 Steering Angle Sensor 10-02-2009 TIMMO Methodology Page 20 10