copyright © claytex services limited 2015 systems engineering specialists racing in real-time:...

Copyright © Claytex Services Limited 2015

Systems Engineering Specialists

Racing in Real-time:Multi-domain modelling for Driver-In-the-Loop simulators


Claytex Services Limited

• Based in Leamington Spa, UK– Office in Cape Town, South Africa

• Established in 1998• Experts in Systems Engineering, Modelling

and Simulation– Focused on physical modelling and

simulation using the open standards: Modelica and FMI

• Business Activities– Engineering consultancy– Software sales and support

• Dassault Systemes• rFpro

– Modelica library developers– Training services

• Global customer base


Engineering Consultancy

• Focused on Systems Engineering, Modelling and Simulation

• Active in multiple industries• Examples:

– Development and validation of models– Analysis of systems using existing tools based on

Dymola, Simulink, etc.– Development and integration of models with driving

simulators• From desktop simulators to high performance full-

motion simulators in Formula 1 Indycar, and NASCAR– Development of bespoke tools to support Systems

Engineering• Translation of models between tools/languages• Integration of models in to existing analysis tools and

processes– Process development and improvement

• Requirements Management, Model Specification, Model Management, etc.


Modelica and FMI Development

• Engines Library– Mean value and crank angle resolved engine models

• Powertrain Dynamics Library– Powertrain modelling for driveability and shift quality

• Vehicle Dynamics for Motorsport– Used in Formula 1, NASCAR, IndyCar and Sports cars

• Simulator Integration– Integration of VDLMotorsports and rFactor Pro

• FlexBody Library– Flexible bodies from Nastran, Genesis and Abaqus

• SystemID Library– Neural networks for non-linear system identification of dynamic systems

• XML Reader– Enables the use of XML files for parameters in Modelica

• FMI Blockset for Simulink– Import FMI compliant models in to Simulink


• Distributors of rFpro and Dassault Systemes solutions

Multi-domain modelling and simulation based on Modelica, supporting multiple physical domains in a single integrated simulation environment

For managing requirements traceability and impact analysis across hardware and software projects lifecycle

Design, validation and deployment of control system software using IEC 61131-3 languages for safety critical systems

A suite of design and functional tools to develop AUTOSAR compliant embedded software

Specialist products within CATIA covering every aspect of Systems Engineering including requirements, functional architecture, control design and physical modelling

rFactor Pro focuses on simulators for engineering development of vehicle dynamics and the control systems and active safety systems that affect vehicle dynamics.

Software Portfolio


Introduction

• Driving simulators increasingly used in both Motorsport and Automotive

• Originally introduced in Motorsport for driver training

• Allows tests to be completely safe and in repeatable conditions

• Due to testing restrictions now used to evaluate new designs, new technologies and work on car setup before arriving at the race track

• Broad range of approaches to suit different needs– Desktop system– Small motion systems with 3-4 dof– Full motion platforms with 6 dof

• Entertainment systems• Engineering development systems


Example Motorsport System

• Simulators for engineering development• Ansible Motion Series 1 platform

– 6 degrees of freedom– Large excursions possible on all axes– High frequency range for realistic motion

cueing• rFactor Pro graphics, sound and track

data– Low latency and high bandwidth offering

the fastest video & audio pipelines– Extensive range of tracks available for

Motorsport and Automotive applications• Dymola based vehicle dynamics model

– Multi-domain vehicle model


Example Desktop System

• Able to evaluate baseline capability of a vehicle or enable detailed assessment of a control system• Key features:

– rFactor Pro provides the core capability • Range of test scenarios (race tracks, proving ground)• High quality graphics

– Podium Technologies PTWinSim• Host for the physics model enabling real-time telemetry

streaming• Supports running multiple models from Dymola,

Simulink, C/C++– Dymola vehicle model

• Full MultiBody chassis model– Telemetry system

• Gredi used to view data in real-time from the model– Logitech steering wheel and pedals (gaming system)– 1 PC used for the complete system

• 1 for the simulator (graphics, physics, etc.)• Optionally separate pc for calibration and telemetry tools


Generalised architecture

• Driver interface – Single LCD to multiple projectors– Gaming wheel and pedals to sophisticated hand

wheel loading system– Motion platform

• Graphics system– Typically based on gaming technology such as

rFactor Pro but specially developed for DiL• Physics model

– Appropriately detailed model of the car to be tested• Desktop system might be just 1 PC• High-end driving simulator

– 8+ PC’s (1 per projector, 1 for physics, 1 for motion, 1 for telemetry, 1 for overall coordination)

• Options to integrate HIL systems


Dymola and CATIA Systems

• Dymola is a standalone tool • CATIA Systems is integrated into the

3DEXPERIENCE platform– Core functionality is the same, only the user

interface changes– Easy to move models between the two programs

• Multi-domain modelling and simulation of complex dynamic systems


Component Orientated Modelling

• Modelling and simulation of systems integrating multiple physical domains– Mechanics (1D, MultiBody), 1D Thermofluids,

Control, Thermal, Electrical, Magnetics and more• Promotes extensive model reuse at component

and system level– Components represent physical parts: valves,

gears, motor– Connections between parts describe the physical

connection (mechanical, electrical, thermal, signal, etc.)

• Store your own component and system models in libraries to easily share and reuse them across the business


Model Definition

• Models are defined using the Modelica modelling language– A generic modelling language– Design for convenient, component orientated modelling of complex multi-domain systems– Models are defined as differential algebraic equations (DAE)

• Dymola provides access to the Modelica code behind models

model Inertia extends Interfaces.Rigid; parameter SI.Inertia J=1 “Moment of Inertia”; SI.AngularVelocity w “Angular velocity”; SI.AngularAcceleration a “Angular acceleration”;equation w = der(phi); a = der(w); flange_a.tau + flange_b.tau = J * a;end Inertia;


• A freely available, open source, standardised modelling language• Developed and maintained by the Modelica Association

– An independent, international not-for-profit organisation– Established in 1996– Currently over 100 members from academia, tool vendors and industrial end-users

• Anyone can get involved

• Organised into project groups for the Modelica Language, Modelica Standard Library and FMI Standard

• The Modelica Standard Library contains basic models in many engineering domains


Modelling Approach

Example: Inverted Pendulum

• Classic problem in control and dynamics– Representative of a missile flight control problem

• The centre of gravity is located behind the centre of drag causing aerodynamic instability

• To design and tune the controller requires a model of the system

• The systems contains the following:– Mechanics in the cart and pendulum– Electric motor to drive the cart– Control system with sensors and actuators


Modelling Approach

Traditional methodology

• Determine all the equations that capture the system behaviour

• Manually rearrange and solve the equations• Implement the solution in C, Fortran, Simulink, etc.• Problems with this approach:

– Cannot easily change the properties of individual components (mass, length, resistance, etc.)

– Cannot easily reuse the model or subsystem models for other tasks

– Cannot easily change the detail in one part of the model


Modelling Approach

Modelica based approach

• Discretise the system into subsystems and components

• Define the system architecture and physical connections between subsystems

• Implement the subsystem models and plug these in to the architecture

Control

Electrical & 1D Mechanics

MultiBodyMechanics


Symbolic Manipulation

• The model equations are automatically transformed in to the required solution for simulation• Advanced mathematical techniques are used to reduce the size of the problem without removing detail

• What does this mean in practice• The Inverted Pendulum contains 659 equations

– Using the Modelica modelling approach these are formed as a DAE• Symbolic manipulation automatically reduces this to:

– 7 continuous time states– 92 other time varying quantities

• Including 1 linear system, originally containing 14 equations but reduced to a system containing just 2 equations– All the other equations relate to constants or variables that are exactly equal to these 99 variables

• Advantages of Symbolic Manipulation– Automate the often error prone process of rearranging equations in to a solution– Apply advanced mathematical techniques to reduce the size of the problem– Can deliver real-time simulation performance of Vehicle Dynamics models with over 100,000 equations (1ms

time step)


Model Reuse

Benefits of the Modelica Approach

• Fast model creation through drag-and-drop of components

• No manual rearrangement of model equations required– Eliminates a difficult and tedious task– Symbolic manipulation is used

• Models can easily be replaced with more detailed representations– Model architecture remains the same but new subsystem

models can be plugged in provided they have the same physical connections

• Subsystems can easily be reused for different analysis tasks– For example, invert the physical model to determine the

control inputs required– Here the angular response of the pendulum to a

disturbance is prescribed and the required input to the power supply will be calculated


Modelica Application Libraries

• Air Conditioning• Belts• Build Tools• eDrives• Engines• FlexBody• Flexible Bodies• Fuel Cell• Heat Exchanger• Human Comfort• Hydraulics• Liquid Cooling• Pneumatics• Powertrain Dynamics• Simulator• Smart Electric Drives• SystemID• Terrain Server• TIL Suite• Vapor Cycle• Vehicle Dynamics• VDLMotorsports• XMLReader


Dymola in Motorsport

• Design– Enables engineers to quickly evaluate the impact

of design changes on the complete system– Offline and real-time simulation

• Test– Use the models to support off-track testing– DiL and HiL simulations

• Race– Use the models trackside for setup optimisation

and with the telemetry system– Integrate into lapsim and trackside tools


Vehicle Dynamics for Motorsport

• VDLMotorsports Library– Add-on to the standard Vehicle Dynamics library– Used in Formula 1, IndyCar, GP2, NASCAR and

sports car racing• Includes adjustable suspension

– Specify shim thickness to adjust track rod, pushrod, etc.

• Kinematic and compliant suspension models• Pacejka tyre model• Wide range of experiments for K&C and

dynamics plus setup and quasi-static tests• Real-time capable MultiBody models• Open and extendible


Simulator Toolbox

• Enables VDLMotorsports models to be compiled ready to run with rFactor Pro– Simply plug the vehicle model in to the template

and execute the build function• Compiles model to work with PTWinSim and

McLaren Electronics vTAG• Solution proven on several motion platforms

– Ansible Motion– McLaren Electronics– Moog

• Supports full range of rFactor Pro features– HD Terrain Server and multiple tyre contact points– Collisions


Dymola Demo


Summary

• Modelica and Dymola can be used to create MultiBody vehicle dynamics models suitable for use in real-time applications– Can also include mean value engine models and energy recovery systems to model the whole system

• Using Dymola, new design ideas and concepts can be quickly modelled and compiled for use in the simulator– Enables real drivers to start evaluating these ideas at a very early stage in the development process– The simulator usage increases and is brought earlier in to the development process


Contact

For further information please contact:

Mike Dempsey

Claytex Services Ltd.

Edmund House

Rugby Road

Leamington Spa

CV32 6EL

UK

Tel +44 1926 885900

Fax +44 1926 885910

[email protected]

copyright © claytex services limited 2015 systems engineering specialists racing in real-time:...

Documents

control systems

aspect of systems engineering

active safety systems

simulink slide

safety critical systems

software portfolio slide

physical modelling rfactor

simulation active