2017

Adopting Model Based System Development

Joshua Spiegel, Brian Ladson, M. Michael BriggsPresented by: Brian Ladson

Modeling and Simulation Engineerbladson@meicompany.com

Millennium Engineering and Integration CompanyNovember 1, 2017

Millennium Engineeringand Integration Company

1

2017

Simulation-Driven Development• “An approach to engineering that uses models as an integral part

of the technical baseline that includes the requirements, analysis, design, implementation, and verification of a capability, system, and/or product throughout the acquisition life cycle.” Final Report, Model-Based Engineering Subcommittee, NDIA, 2/2011

• Traditional Systems Engineering• Manual processes executed throughout top-down decomposition &

bottom-up realization, i.e. the ‘V’• Process lacks verification that requirements are satisfied

• Model Based Engineering/System Development (MBE or MBSD) fits naturally into the workflow with Models & Simulations integrated into each process phase

• To fully take advantage of MBSD for complex systems, tools that can simulate continuous and discrete time dynamics and generate real-time code are needed

• MATRIXx, LabVIEW, MATLAB / Simulink, SCADE, etc have Automatic Code Generation

2Simulation-Driven Development Achieves Substantial Reduction in

Software Life Cycle Cost & Improves Software Operational Reliability

2017

Seamless Model-Based Engineering• Model Based Systems Engineering (MBSE)

& Model Based Engineering (MBE) are an integral part of the Systems Engineering ‘V’

• Graphically-programmed models enable simulation-driven concepts, design trades, and early optimization

• Model Based Development substantially reduces development time / cost of complex systems• Engineering automation software tools

accelerate design via a re-usable library of pre-programmed functional objects with an integrated simulation engine

• System simulation availability speeds up trade studies and sensitivity analyses

3

Algorithm Blocks

Model Software

Model Based Development Process

Simulink Template

Improved Coding Accuracy and Reduced Development Time

2017Model Based Systems DevelopmentToolchain & Processes

4

Requirements

& Traceability

UML/SysML

Diags Model

Files &

Code

Scripts &

Code Integ.

w/Middleware

Requirements

Database Test

Results

DB

Block-diagram Sim Models

of HW & SW functions• NRT System Simulation

Code Generator

Embedded

Target Processors• RT Plant Simulator for PIL/HIL

• Flight Processor or Surrogate

External Simulation

Frameworks

Requirements

Management Tool

Real-Time Integrated

Development Environmnt• RTOS & Runtime environment

• Compiler, Linker, Loader etc

• BSP & IPC software

CM/VC• Config Mgmnt

• Version Control

• Build Management

Load

Module

Standalone Model

Builds

Generated RT

Source Code

& Make Files

Test

Vectors

External Code

Comms Middleware, Code Gen Control & Parsing Scripts

Legacy Models & Code• C++ Source Code, Simulink Blk Diags

UML/SysML Tool• Structure/Object Diagrams

• State Charts

• Sequence Diagrams

Back-propagate changes

2-way Translator

Requirements

& Traceability

Model

Files

Model File

Test

Results

DB

UML/SysMLDiags

Database

Block Diagram

Model Files

Middleware(optional)

Ext

Test

Results

DB

MBSE & MBE Tools

MBE Tools

Multiphysics Model Data

2017

Phased Strategic MBSD Adoption Approach• Investment Required:

• Significant Adaptation in Corporate Software Development Process

• Purchase of Multi-User Licenses for Multiple Mathworks Software Tools: MATLAB/Simulink/RTW/Stateflow, etc.

• Training / Retaining of Personnel• Living With Resistance to Change and Perception of

Increased Performance Risk Until Benefits Have Been Demonstrated

• Transition Legacy Processes and Code to align with MBD

• Expand Modeling Guidelines, Model Libraries, and V&V Process

5

Investment

Be

nef

it

A Phased Strategic Approach and Key Investments are Required to Adopt Model Based System Development and Realize its Benefits

2017

Transitioning Legacy Processes and Code• Legacy Models, Simulations, and Design Processes represented as

MANY lines of code• Legacy Code & Processes need NOT be abandoned – most can be used

and maintained in the Model Based Development Environment• Rapid Plug-and-Play, Drag-and-Drop architecture leverages legacy

models and simulations

• Many organizations interested in transitioning to Model Based Development Processes• Why don’t they OR haven’t they transitioned yet?

• Time, Cost, OR Lack of Path to Convert Large Scale Proven Legacy Models and Simulations to Model Based Environment

• How can they transition?• Legacy Models and Simulations are transitioned to the Model Based

Environment via Automated Tools which reduce Time, Cost, and Human Error which were once precluding factors

6Legacy Models and Simulations are Integrated Directly or Transitioned

to the Model Based Development Environment

2017

Expanding Modeling Guidelines & Model Libraries

• Common model repository enables software verification and validation (V&V) in a parallel model environment before implementing on critical operational assets

• Automated evaluations ensure Model Based Systems are developed, implemented, and integrated as intended and follow set modeling guidelines for ease of readability & requirements traceability

• Well designed, Integrated Models Facilitate Configuration Control and Rapid Change Implementation • Traceability between requirements and other model elements become a set of living linkages

that provide key insight into system dependencies

7Expanding Modeling Guidelines & Model Libraries Enables a Seamless

Model Based Systems Development Process

2017

Automatic Code Generation• Automatic Code Generation is Vital to Model Based Development Processes

• Leverages graphical programming language to rapidly prototype simulations in Monte Carlo space and integrate with external software / hardware

• Hours-to-days to accomplish initial capability assessments early in system life cycle

• Custom Code Generation Tools target desired Middleware and significantly reduce time required / error associated with transitioning prototype to an integrated system• Automatic Code Generation techniques utilized to produce real-time software products for

complex systems including flight vehicles

8

2017MBSE Payoff Examples:Telerobotic Remote Ops With Latency Compensation& Virtual Haptic Feedback (for DARPA Phoenix)

9

2017

MBSD Applied to NASA Ames LADEE Flight Software• Lunar Atmosphere and Dust Environment Explorer (LADEE)

• Lunar orbiting spacecraft• Structure based on modular bus developed by NASA• Objectives

• Measure dust & atmosphere properties around Moon• LaserCom experiment

• Launch: Sept 2013, Wallops, on a Minotaur V, 7-Month Mission• Millennium Roles since early 2009

• Flight Software Development • Real-time Simulation Development• Mission Ops Support

• Rapid Development Infrastructure• Simulink-centric Model based Development with Embedded Coder• Loosely-Coupled Architecture (cFE)• Early and Frequent Integration

• Early Integration in P/HIL Testbeds• Evolving fidelity as H/W becomes available• Early Integration of Device Protocol Software

• Posix I/O Drivers Approach• Facilitates Mix’n’Match Evolution of transports• Meets LADEE Testbed Implementation Goals 10

2017

LADEE Loosely-Coupled Flight Software Environment

11

Command

& Mode

Processor

Actuator

Manager

State

Estimator

Safe Mode

Controller

Attitude

Control

System

Thermal

Control

System

Power

Control

System

SchedulerLimit

Checker

Stored

Commands

Memory

Scrub

Memory

Manager

Memory

Dwell

Hardware

I/O

Health &

Safety

Data

Storage

File

Manager

Telemetry

Output

CCSDS File

DeliveryChecksum

Command

Ingest

House-

keeping

Software Bus

Telemetry

Gnd Cmds

Sensor Data

OFSW

System Support, O/S Services and Device Drivers

Battery

Charge

System

FSW Internal

FSW ExternalSimulink

Task

cFS

Task

Hand

Written

Task

KEY

2017

LADEE Processor/Hardware-In-Loop Simulation: Spacecraft Sim & Embedded Code Generated by Simulink Embedded Coder

• Flight code generated from Simulink, runs on Flight Avionics EDU• Provides testing of FSW with Avionics I/O• Definitive answers on resource utilization• Highest fidelity simulations for verification/validation 12

2017MBSD Payoff Example:Payload Modular Open Architecture

13MBSD Enabled Rapid Integration, Test, and Proof of a Customer Defined

Architecture using Models & Algorithms from Common Repository

2017International Space StationFlying 1,000,000 Lines of Autocoded ADA• Pointing & Support Portion of Guidance,

Navigation & Control Flight Software• Flight Code for All Onboard Experiments

• Solved Boeing’s problem of verifiying & validating mandated Ada code from dozens of experiment suppliers

• All suppliers used the MATRIXx/SystemBuild/Autocode toolset to develop Ada code and test it on a Space Station “Application Generator” with ISS Real-time target processor

• Original intent was rapid-prototyping: NASA decided to use 1,000,000 lines of Autocoded ADA inflight when it was discovered that the generated code was bulletproof

14

ISS

2017PhantomWorks Post-Transition-to-MathWorksExperimental Vehicles: X-40a, X-43• X-40A Space Maneuver Vehicle (9000 ft drop

test to autolanding)• Simulink simulation validated against NASA

Fortran sim• 6 weeks to initial code delivery• 1 week turn on changes

• X-43 (Hyper-X) Scramjet Research Flight Experiments• Flight software for propulsion & flight control

systems developed using Simulink & RTW• Reduced development time by months• Aided Boeing in achieving SEI CMMI Level 5

software rating

15

X-43 (Hyper-X)

X-40A

2017

Summary: Model Based System Development Payoffs• Graphically-programmed models enable simulation-driven concepts, design trades,

and early optimization• Integrated Engineering Toolkit Enables Rapid Design/Development• Rapid Plug-and-Play, Drag-and-Drop architecture leverages legacy models and sims• Analysis activities that used to take months are now measured in hours or days• Modifications and technology injections are accurately characterized much quicker

than legacy development processes allow• We provide support and training for customers who want to adopt advanced MB

engineering techniques and processes

16MBSD Substantially Reduced Development Time and Cost, Increased Product

Robustness and Reliability, & Accelerated Integration, Test, and Validation