Advanced Training on System designregister.ansys.com.cn/ansyschina/ugm2014/material/slide... ·...

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Advanced Training on System design

ANSYS UGM Conference May 2014

Thierry Le Sergent SCADE System product manager


Agenda

• Basics in Model Based Systems Engineering

• Simple example with SCADE tools

• More tool needs for industrial process o Data management o Tool configuration

• Industrial example : aircraft braking system

• Q&A


Example of Complex System

Moving Mechanics

With Electric Drives In a Fluid

Environment... Controlled by

Software!


System Engineering

• Methods & guidelines to manage complexity

• Example in aeronautics domain

ARP-4754A Guidelines for Development of Civil Aircraft and Systems (SAE Standard)


ARP-4754A and other Civilian Avionics Standards

Aircraft & System Development Processes

ARP 4754A / ED-79A

Safety Assessment Process Guidelines & Methods

ARP 4761

Electronic Hardware Development Lifecycle

DO-254 / ED-80

Software Development Lifecycle

DO-178B / ED-12B

Intended Aircraft

Function

Function, Failure & Safety Information

System Design

Information

演示者

演示文稿备注

Scade systrem is at the heart of the process


ARP-4754A: Development AND Safety

System Development Process Safety Assessment Process

FHA Functional

Hazard Analysis

PSSA Preliminary System Safety Assessment

SSA

System Safety Assessment

Certification

CCA

Common Causes Analysis

Aircraft Function Development

Allocation of System Requirements to Items

System Implementation

Allocation of Aircraft Functions to Systems

Development of the System Architecture

Implementation

Aircraft Functions

System Functions

Safety Requirements

Item Requirements

演示者

演示文稿备注

The system development process is cascaded in the grey box on the right of the picture. I will not enter into the details of the safety assessment processes on the left part of the picture, but I will just highlight the important information exchanged between the 2 parallel processes. From the aircraft level requirement, the system development process is made of 4 stages, each with a very important outcome. First the requirements are analyzed and decomposed into functions. This functional design is an important input for the safety assessment process to perform the system level Functional Hazard Assessment. Second, the physical architecture of the system is designed. Note that the safety assessment provides safety objectives for this architecture. Of course, the functions must be allocated to the components specified in the system architecture design. This system architecture design is also analyzed from the safety assessment perspective with a Preliminary System Safety Assessement. The next step of the System development process is to allocate the architecture components to SW or HW. and finally each system architecture component is implemented What is important to remember is that from the functional decomposition and the architecture design, the safety assessment process provides safety requirements for the architecture components, and defines the Development Assurance Level, the DAL. This is the famous level A from DO-178B for the most critical functions developed in software, to level D for the non critical functions. So at the end of the safety assessment process and system development process you know what are the SW components, and what is their DAL level.


Function vs Architecture

• Takeoff and Land • Sense Position and Velocity • Navigate • Produce Horizontal Thrust • Produce Vertical Lift

Architectural Definitions Functional Decomposition

http://monia2009.centerblog.net/5974-Astre-Soucoupe-volante?ii=1


Example: “Emergency Floatation System”


Typical Systems Engineering Documents

Function Float_CP EMERGENCY_ FLOATATION_ UNIT

AMC2 Rh_ASU LL_AU WIS1

To acquire inflation command

To detect helicopter immersion

To acquire the information to authorize or not the inflation

To compute conditions to enable/disable inflation

To inflate the floats

Physical interfaces Functional interfaces

DI_IPB_WATER_DETECTED Water_Immersion; Immersion_status

RT_WIS1_SENSOR

Water_Immersion; Immersion_status; Height above water; ON_GND_Detection; Airspeed

LH Jettison

N/A

RH Jettison

N/A

PW_FRONT_LH_CARTRIDGE1

Trigger_Bottle


Trigger_Bottle

Functional Design

Architectural Design

Functions & Interfaces Allocation

Requirements

Data

演示者

演示文稿备注

Traditional tools used to implement the system development processes are Word and drawing tools such as Viso, for both the functional design, and the architecture design. And typically excel sheets are used to specify the function and interface allocation to architecture components. Important things to remember: Draws are important; it is the usual communication means for engineers working in as many different areas as mechanics, electronics, or SW engineering. - Tables are nice for verification activities, and support large scale models. But this traditional means have a major inconvenience: they are not “model based”. I mean here that the graphical designs and the allocation table are physically independent; so if one modifies either side, the change must be taken into account manually at the other side. This synchronization is both painful, time consuming and likely to introduce bugs in the process. And this issue does not concern only the system engineers for the consistency of the functional and the architecture decomposition; the components that are developed in SW must also be synchronized with the definition of the system components made by the system engineers. The system to SW interface synchronization is one of the mayor benefits that the SCADE tools offer as I will show you in the demo.


Main pains expressed

• Main pains expressed by system engineers o Multiple independent techniques and tools to study specific aspects

of a system o Design activities between the different disciplines are often

redundant (e.g. Control System, Safety analysis, Software design)

o Consistency and reconciliation issues when updates occurs o No global view shared by all engineers

• High level requirements expressed o One graphical representation, standardized o Usable in multi-disciplinary contexts o Allowing analysis supported by tools


MBSE formalizes the practices of Systems Engineering through the use of models and

organizes models-centric activities instead of documents-centric activities

Model-Based Systems Engineering


ANSYS Systems Products System

Design & Simulation

System Architecture Design & Verification, Multi-physics

System Simulation

Control Software Design

Prototyping, Design, Verification, Qualified

Code Generation

HMI Software Design

Prototyping, Design, Verification, Qualified

Code Generation

System & Software

Lifecycle Management

Test Creation, Management & Execution, Requirements & Configuration Management,

Metrics & Dashboards, Documentation

Generation


• Available from Esterel Technologies

System Engineering Methodology Handbook


Model-Based Systems Engineering Typical Workflow

Detailed Design Embedded Software, Electronics, Physics Hardware

Functional and Architectural Analysis Modelling of functions and Architecture

Operational Analysis Modelling of operational scenarios

Requirements Analysis Manage textual requirements (Doors, Word, Excel…)

1

3

2

4


Functional

Allocations

Detailed Architecture

System Functional & Architectural Design

Architecture

Functional decomposition and detailed architecture modeling


Functional View

Functional view of Inflation


Architecture View

演示者

演示文稿备注


Allocation of Functions Function Float_CP EMERGENCY_

FLOATATION_ UNIT

AMC2 Rh_ASU LL_AU WIS1

To acquire inflation command

To detect helicopter immersion

To acquire the information to authorize or not the inflation

To compute conditions to enable/disable inflation

To inflate the floats

Functional Allocation in SCADE System Allocation Tables


Allocation of Interfaces

Physical interfaces Functional interfaces

DI_IPB_WATER_DETECTED Water_Immersion; Immersion_status

RT_WIS1_SENSOR

Water_Immersion; Immersion_status; Height above water; ON_GND_Detection; Airspeed

LH Jettison

N/A

RH Jettison

N/A


Trigger_Bottle


Trigger_Bottle

Interface Allocation in SCADE System Allocation Tables


• Not one single System Engineering method/process – Depends on company culture and organization – Depends on pre-existing know-how on the system to develop

• Principle Refine, Trace, Verify

Focus on Functions vs architecture


• 1) Refine

• Keys – Architecture decomposition

• Stop when components can be better design with dedicated tools – SCADE Suite for SW components:

Designs for automated qualified embedded code generation should not be made with SCADE System

– Multi-physics and 3D tools for physical components: A bold or an electronics circuit should not be made with SCADE System

– Function decomposition • One elementary function must be allocated to 1 architecture component • Refine functional decomposition until you can make it

Methodology key points Abstract

(functions) Concrete

(components)

Coarse grain

Trace, Allocate

Decompose

Fine grain


Functions allocation

Pressure Sensor1

Pressure Sensor2

SW code

Provide Pressure

Architecture components

Functions

Not a good specification of what Each component shall do Refine the function so that each elementary functions is fully allocated to 1 component


Functions allocation

Pressure Sensor1

Pressure Sensor2

SW code

Provide Pressure

Measure P1

Measure P2

Average 1s

Average 1s

Max pressure

Architecture components

Functions

Good specification of what each component shall do

And don’t refine further (use SCADE Suite for SW code impl)


• 2) Trace

• Each refinement is traced to the previous level SCADE LifeCycle RMgateway to manage directly end-to-end requirement impact analysis

• 3) Verify

• Verify model consistency – Define you own design rule and automate verification with SCADE System Checker

• Simulate as soon as possible – Functional behavior: SCADE Suite – Multi-physics: ANSYS Simplorer – Both cases: SCADE LifeCycle Rapid Prototyper

Methodology key points


• Support Model Based System Engineering (MBSE) development process o Functional decomposition & architecture design o Allocation of functions on components

• Enable a seamless design process from system design to software implementation o Synchronization of system components with software

implementation

• SCADE System Modeler o Focus on ease of use o Allows graphical multi-views on a system model composing

packages, diagrams, blocks, ports, connectors o SysML based


Simple example Fighter model


Simple example

• Simplified Fighter o Radar o Identification Friend or Foe o Mission computer o Interactive display o Gun

• Textual requirements


Functional decomposition


Functional decomposition


Traceability Model / Requirements


Traceability from SCADE System • SCADE LifeCycle RM Gateway GUI

o A docked-window for immediate visualization, navigation, link


Architecture design


Architecture design Mission Computer


Allocation table

• Leaf functions allocated to leaf components


Model documentation generation


System Model API

• Development of custom verifications, data import or export o Wizard to help creating your first

scripts o TCL, Java and OCL technologies


SCADE System Checker • Automated verification

o For methodological rules and consistency of the model • “Are all functions allocated to a component?” • “Are all functions well connected”

o Easy customization of rules • Predefined rules • User defined rules

o Tool configurations • Select different set of checking rules • Select packages to be checked

For example, different check at: – Functional level – Architecture level

o Run and report • Within IDE or in batch


SCADE System Checker report


SCADE System • System – Software Models Synchronization

o Avoid duplication of efforts and inconsistencies between system structural models and software behavioral models

o System design and Software components evolve independently

o On-demand re-synchronization of interfaces

Interfaces described in SCADE System model

Software designs


System – Software Collaboration

Software System

SCADE System Advanced Modeler Seat


Model Diff/Merge

• Compute, highlight and merge dependencies in 1 click

• User control with “force match” and “exclude match” actions



Model Diff/Merge

• Comprehensive report generation

• Differences before merge session

• Merge actions • Differences

after merge session



Collaboration Capabilities

• Model Component Export o Preserve IP of other system design parts, e.g. to subcontract the SW

development of one system block

• Workflow example o 1/ Export subsystems

• Allow several teams working in parallel on the exported subsystems o 2/ Reintegrate modifications

• Rely on Diff-Merge tool o 3/ Report from reintegration o 4/ Iterate as often as needed



Data management


Comprehensive Data Management with SCADE System

• Systems engineers need to o Manage and produce ICDs (Interface Control Documents),

that are detailed specifications of • all the interfaces between subsystems • all the interfaces of the system with the outside

o Ensure independence between the system architecture and the data exchanged, produced and consumed within the system • Those data may be defined prior to the design of the system architecture

itself (reuse of legacy data)

• SCADE System allows to o Import/export data dictionaries o Allocate data to the architecture, and propagate data along the

communication paths o Manage and produce model-based ICDs

演示者

演示文稿备注

Re-written y EB


Import/export Data dictionary

Direct copy/paste from/to excel

- Creates data, - Binds names to existing information e.g. datatype

<Ctrl> c

<Ctrl> v


SCADE System data

• Data in SCADE system o Objects defined within blocks with a name and a datatype

• (SysML “block properties” renamed “data” in SCADE System)


Exchange of information (between functions or architecture items)

Classical representation in SysML: Info exchanged between items expressed by the ports, carrying in particular a name and a direction.


Exchange of information (between functions or architecture items)

Data-based representation: The ports represent only “gates” through which the information implemented as “data” can circulate. Data are connected to Ports and propagate through the connectors


Data propagation in architecture

OFV_SpeedCommand

CabinPressure1

SpeedCommand

OFV_SpeedCommand = SpeedCommand


• Model based ICDs o At all levels (functional, architecture item, equipment,…) o Supported by customizable tables in each block

• List of data produce/consumed • Data properties • Information extracted from the model (queries)

– e.g. Source/Target of the data, – Communication means properties, …

o ICD tables always in synch with the model, directly exportable to excel

Model based ICDs


Demo

• Data propagation in Fighter example



Benefits

• Better independence between the architecture and the information managed by the system o The data may exist prior to the architecture design o Simple import from excel

• Maintain ICD (Interface Control Document) consistent o Detailed Specification of the interfaces at all levels o Export to excel

• Support traceability with requirements

• Automate verifications o Rule example: “Are all data produced by exactly 1 component, and used

at least once?”


CUSTOMIZE the SCADE System Modeler


SCADE System Configurator

• Customize SCADE System for a Customer specific domain, as well as standard domains such as IMA, AUTOSAR, etc…



SCADE System Configurator Workflow

SCADE System Configurator SCADE System Modeler

Define customized object kinds, derived from SCADE System objects

Equipment - propX - propY

Bus - propZ

Function - prop1 - prop2 Configuration

Plug-in

Generate

Deploy

Specialist End-User

Domain specific modeler



Definition of Domain-Specific Objects

• Definition of domain-specific objects o Function, Equipment, Bus, … o Domain specific objects properties and inter-objects constraints



System Modeler IDE Customization


• IDE customization o Dedicated user interface palettes o Dedicated property view



Automatic Packaging of Configuration


• IDE customization o Dedicated user interface palettes o Dedicated property view

• Automatic packaging of the SCADE System Configuration o SCADE System Configuration managed as a SCADE project o Simple deployment on SCADE System end-user machine



Demo

• Workflow example o 1/ Create simple configuration project o 2/ Deploy the configuration o 3/ Create simple configured project o 4/ Exploit the configured project for code generation

o Video



Braking System


Braking System

62


Braking System

• System Requirements

• System model: 3 levels o Functional

• Exchanges of functional data between functions o Software

• Introduction of redundancies, messages, … • Functions are realized by Software components

o Hardware • The CPU, switches, … • Software components are allocated to Hardware components

• Software design o Requirements o SCADE Suite model from which the embeddable code is generated



Braking System Traceability

64



• 1/ System Requirements – System model o Trace the System Functions to the System Requirements o Some requirements are traced to the Software and Hardware levels o Supported by SCADE LifeCyle Requirement Management Gateway


1/



• 2/ Within System model o Functions allocated to Software components o Software components allocated to Hardware components o Supported by SCADE System allocation o Can be shown in SCADE LifeCyle Requirement Management

Gateway for end-to-end impact analysis


2/



• System to Software o 3/ Models: automated translation of Software components defined

in System model give the traceability to the Software architecture o 4/ System Requirements allocated to Software are refined in the

Software HLR document. Traceability with RM Gateway o 5/ Behavioral design in SCADE Suite is traced to the Software HLR

document with RM Gateway


3/

4/

5/


Braking System items (Traceability)

68


Functional View


Software View (AFDX Messages)


Physical View


Mapping View (Partition)


ICD Table in SCADE System

• Focus on ADIRU

ADIRU DATA

Easy to fill from Excel (Ctrl^C Ctrl^V)


ICD Table in SCADE System

• Provided in the tool (Model based approach)

• Kept consistent

• Available to designer

• No Export function needed just Crl^C Crl^V to export to Excel


ICD Source Destination Parameter Name TypeCOM ACMS AFDX_AB_MODE_LOW NullCOM ACMS AFDX_AB_MODE_MED NullCOM ACMS AFDX_AB_MODE_MAX NullCOM ACMS AFDX_AB_FAULT NullCOM ACMS AFDX_AB_LOW_ACTIV NullCOM ACMS AFDX_AB_MED_ACTIV NullCOM ACMS AFDX_AB_MAX_ACTIV NullCOM COCKPIT O_B_LOW_ON NullCOM COCKPIT O_B_MED_ON NullCOM COCKPIT O_B_MAX_ON NullCOM COCKPIT O_B_STK_LIGHT NullCOM COCKPIT O_B_LG_LEVER_UP_BAULK NullCOM COCKPIT O_B_LOW_DECEL NullCOM COCKPIT O_B_MED_DECEL NullCOM COCKPIT O_B_MAX_DECEL NullCOM COCKPIT O_B_BPPS Null

MONCAS1CAS2CAS3

ACPTNull

MON CAS1;CAS2;CAS3 SYSTEM_CONF Null

MONCAS1CAS2CAS3

BF_BCS_ACPT_LOW_PRESNull

MONCAS1CAS2CAS3

BCS_LBP_RATIO_VALNull

MONCAS1CAS2CAS3

BCS_RBP_RATIO_VALNull

MONCAS1CAS2CAS3

BF_BCS_SV1_JOP Null

MONCAS1CAS2CAS3

EF_BCS_RELEASE_FLT_WHEEL12Null

MONCAS1CAS2CAS3

BCS_BRKSELV1_UNWANTNull

MONCAS1CAS2CAS3

BCS_BRKSELV1_JCLNull

MONCAS1CAS2CAS3

BCS_B_SYST12_FAILURENull

MONCAS1CAS2CAS3

BCS_VAL_WHEELSPEED1Null

MONCAS1CAS2CAS3

BCS_VAL_WHEELSPEED2Null

MONCAS1CAS2CAS3

BCS_BF_AS_BRK1_LOSSNull

MONCAS1CAS2CAS3

BCS_BF_AS_BRK2_LOSSNull

ADIRU COM ADIRU_AC_GND_SPEED NullADIRU COM ADIRU_AC_ACCEL NullADIRU COM ADIRU_AC_PITCH_ANGLE Null

COCKPIT COM I_U_LBP NullCOCKPIT COM I_U_RBP NullCOCKPIT COM I_U_BPPS NullCOCKPIT COM I_B_LG_UP NullCOCKPIT COM I_B_LG_DOWN NullCOCKPIT COM I_B_ASOFF NullCOCKPIT COM I_B_AB_1 NullCOCKPIT COM I_B_AB_2 NullCOCKPIT COM I_B_AB_3 NullCOCKPIT COM I_B_AB_4 NullCOCKPIT COM I_B_RTO NullCOCKPIT COM I_B_STK NullCOCKPIT COM I_B_PARK_ON Null

Nom de paramètre unique par partition


Synchronization with SCADE Suite & SCADE Display

o Synchronization in both direction between the SCADE System model and SCADE Suite partitions model


SCADE Solutions for IMA Compliant Systems


SCADE IMA Solution Approach

• Solution build on top of SCADE System to overcome SysML drawbacks o Dedicated IMA objects (SCADE System Configurator) o Specific management of instances o Data Management Capabilities

• Objectives o Provide an IMA Designer Editor o Perform Checks (Projection Constraints like Segregation, Platform

constraints like resource Usage & Envelope) o Ease collaboration between OEM and Application provider o Generate Configuration Tables and ICD tables o Scheduling analysis o Encoding Decoding Data (like ARINC 429) o Simulation o Documentation Generation and Traceability (Lifecycle)


SCADE IMA Configurator model On going work

• Current Status o Logical View o Hardware View (simplified) o Mapping – Projection o Resource Definition Usage Envelope mechanism

• On Going o Attribute Settings o Projection Constraints capture (segregation, …) o VxWorks Table generation o Scheduling Analysis o Data Management o Checks definition (allocation constraints, Platform Constraints)


Logical-SW


Physical-HW


Mapping Logical / Physical (PARTITION)


Resources


• Ensure determinism of system behavior and standards compliance o Determinism of generated code o Qualified code/table generation capabilities (for DO-178B/C Level A) o Conformance to ARINC 653 standard

• IMA resources management (sizing, optimization and Checks)

• Communication Management (Message Definition in link with ICD, VL definition)

• Automation of IMA configuration table generation (On going work with WindRiver)

• Scheduling Analysis (On going work with SymTAVision)

• Certification according to DO-178B & C

SCADE Solutions for IMA Expected Benefits


SCADE System Summary Benefits


SCADE System Summary Benefits • Support System Engineering development process

o Functional decomposition & architecture design o Allocation of functions on components o Data import, export, link with architecture

• SCADE System Modeler o Focus on ease of use, Allows graphical multi-views o Based on the SysML standard notation o Model API for the development of custom verifications, import or export

• Enable a seamless design process from system design to software implementation o Traceability with other tools via SCADE LifeCycle RMGateway o Automatic generation of reports with SCADE LifeCycle Reporter o Interfaces synchronization of system components with software

implementation

A Model–based solution… much more than a “drawing” tool and plain databases


THANK YOU

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