asm – gasoline engine simulation package 6 automotive simulation models fuel system the fuel...

dSPACE

ASM – Gasoline Engine Simulation Package

dSPACE Automotive Simulation Models – ASM

NEW: Gasoline Engine Model and ASMParameterization

20072

Automotive Simulation Models

Gasoline Engine Simulation Package

Real-Time Gasoline Engine Model

Key Features Open MATLAB®/Simulink® model

Real-time simulation and offline simulation

Mean value engine model with combustion torque modulation

Direct and manifold injection supported

Description Application AreasThe Gasoline Engine Simulation Package is an open Simulink model for the real-time simula-tion of gasoline engines. It is fully integrated into the dSPACE tool chain and typically used on a dSPACE Simulator for hardware-in-the-loop testing of electronic control units (ECUs). It is a complete and independent engine model that supports all the relevant phases of the model-based development process, from early controller design to testing in the laboratory.

Key BenefitsSince the Gasoline Engine Simulation Package is an open Simulink model users can simply add components or replace them with custom models to meet specific project requirements. All dSPACE Automotive Simulation Models (ASM) have stan-dardized interfaces between subsystems (engine, transmission, vehicle), so the engine model can easily be expanded by adding a vehicle model for virtual vehicle tests. Models parameters can be tuned while online simulations are performed (p. 10).

Simulation Model CharacteristicsThe actual physical engine characteristics are represented by a mean value engine model with crank angle based torque generation, tur-bocharger, exhaust gas recirculation, dynamic manifold pressure, temperature calculation, and direct and manifold injection models. To simu-late the engine within an automotive system (car or truck), the engine model incorporates a longitudinal drivetrain model with manual and automatic transmission, a clutch, a torque con-verter, a starter, and a test bench mode. Models for the environment and driver complement the virtual powertrain.

Offline and Online SimulationThe ASM gasoline engine model can be used in combination with real controllers in a hard-ware-in-the-loop environment (known as HIL or online mode) or for offline-simulation of a gasoline engine in combination with software controller algorithms (PC or offline mode). The model supports real-time code generation via Real-Time Workshop and dSPACE’s RTI for online simulation on a dSPACE real-time system.

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Main Features and Benefits

Feature Description Benefit

Open Simulink model All model blocks are visible Custom models can easily be added or used to replace model components

ASMParameterization Model parameterization comprising calculation and visualization of parameters

Structured parameter handling and fast parameterization (p. 12)

Online simulation Real-time simulation on real-time hardware Hardware-in-the-loop simulations with ECUs

Offline simulation Simulations as early as the design phase Controller validation in early development stages

ASMSignalBus Simulation signals are routed via a structured Simulink signal bus

Standardized and fast access to model variables (p. 11)

Online tunable parameters

Direct parameter access during real-time simulations Online parameter optimizations and behavior studies (p. 10)

Model interoperability ASM models are easy to combine to create a virtual vehicle

An entire virtual vehicle can be simulated (p. 13)

Order Information

Classification Type Order Number

Base Model ASM – Gasoline Engine Simulation Package ASM_P_GE

Extension Models ASM – Vehicle Dynamics Simulation Package ASM_P_VD

ASM – Turbocharger ModelASM – Brake Hydraulics Model

ASM_L_TC ASM_L_BH

Relevant Software and Hardware

Hardware

Required Minimum system Pentium 3 processor, 800 MHz 512 MB RAM

Recommended system Pentium 4 processor, 1.4 GHz or higher Memory ≥ 1024 MB RAM

dSPACE Simulator, equipped with DS1005 or DS1006

Software for Online Simulation

Required Integrated development environment MATLAB/Simulink from The MathWorks®

Real-Time Workshop®

dSPACE implementation software Real-Time Interface (RTI)

dSPACE experiment software ControlDesk

Additional software Microsoft Excel

Operating system Windows 2000, Windows XP (32-bit version only)

Optional Other dSPACE ASM Packages –

Software for Offline Simulation

Required Integrated development environment MATLAB/Simulink from The MathWorks Simulink Performance Tools

Additional software Microsoft Excel

Operating system Windows 2000, Windows XP (32-bit version only)

Optional Other dSPACE ASM Packages –

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ASM Gasoline Engine

Feature Overview Features at a Glance Up to 20-cylinder gasoline applications Simulation with real ECU in hardware-in-

the-loop (HIL) systems Longitudinal driver for standard cycles

(FTP75, NEDC, J10-15, …) Easy to expand into a comprehensive

virtual vehicle by adding ASM vehicle dynamics

Vehicle and engine parameters tunable online during run time (ControlDesk)

Modular, library-based implementation Physical turbocharger as an optional

module Fully integrated into dSPACE tool chain Easy variable access Custom models can be integrated Comprehensive documentation with

complete formula listing

Model Components

The gasoline engine model consists of subsystems that comprise a complete fully featured engine with basic models for drivetrain, vehicle dynamics and environment. The model can be extended by adding other model packages from dSPACE or custom models.

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Engine Torque Engine Speed

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Engine Air SystemAir SystemThe air path simulates the compressor, inter-cooler, throttle, and intake manifold dynamics on the intake side, and exhaust-gas recirculation (EGR) with cooler and exhaust manifold on the exhaust side.

Components and Characteristics Map-based turbocharger for boost

pressure calculation Intercooler Throttle Intake manifold with calculation of intake

manifold pressure and temperature, fresh air mass and exhaust mass

Exhaust manifold with calculation of exhaust manifold pressure and temperature

Exhaust-gas recirculation (EGR) of exhaust and fresh air with EGR cooler

Lambda before and after catalyst Exhaust backpressure and temperature Optional: ASM – Turbocharger Model, the

physical turbocharger model with compres-sor and turbine (VTG or wastegate) and with turbine speed calculation

Numerical stabilization using subsystem oversampling (p. 10)

Schematics of the air system.

Look-up table for gasoline engine volumetric efficiency.

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Fuel SystemThe fuel system can simulate direct and mani-fold injection systems. The fuel mass flow for manifold injection is calculated from the mea-sured injection time. The injected fuel mass for direct injection can be simulated as mean flow or pulse-wise.

Wall FilmDuring manifold injection, some of the injected fuel feeds the cylinder directly, while the rest forms a film on the intake manifold wall. Liquid from the wall film evaporates over time, contrib-uting to the air fuel mixture process and entering the cylinder. The wall film model describes the fuel transport from the injection valve to the cylinder by means of a mean value approach.

Components and Characteristics Fuel injection system: common-rail system

including direct injector and manifold injector

Tank model Injectors

The air fuel mixture process takes wall film fuel evaporation into account.

Piston EngineThe piston engine model comprises the air flow through the inlet valve and the combustion torque calculation. Two combustion models are available, for homogenous and stratified mode. The effects of the ignition angle, the injection angle, and the air/fuel ratio on the combustion torque are included as efficiencies. Friction torque is taken into account for effective torque calcula-tion. As in a real ECU, the torque-based soft ECU (p. 8) provides strategy functions for switching between the modes.

Components and Characteristics Mean value engine model with

combustion torque modulation Homogenous and stratified combustion Effect of lambda and ignition angle by

efficiency tables Cylinder inlet by volumetric efficiency Friction torque Basic cooling system

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Engine Fuel System

Mathematical equation for torque calculation.

Trqeff – Effective torquepind – Induced pressurei – Engine constant (0.5 for four strokes)VD – Engine displacementTrqfrict – Friction torque

Piston engine model includes crank angle based torque calculation.

Trqeff = – Trqfrict

pind . i . VD

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Engine Torque Generation

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Drivetrain and VehicleDrivetrainThe drivetrain model calculates the speeds of the vehicle drivetrain, for example, the engine speed at the crankshaft and the speeds of the transmission. The drivetrain can be disconnected in test bench mode, in which the engine speed can be controlled by a dynamometer and the engine torque by actuating the accelerator pedal. For stationary machines (without drivetrain), the load torque can be stimulated manually.

Components and Characteristics Crankshaft for engine speed calculation Automatic transmission by torque

converter and lockup clutch Manual transmission by mechanical clutch Differential Starter Test bench for engine speed and torque

control Manual load torque for stationary

machines

Vehicle DynamicsThe vehicle speed is calculated according to the external forces on the vehicle. It is described by a longitudinal model of a passenger car or truck. Air resistance, slope, braking, and rolling resis-tance are taken into account.

Components and Characteristics Slope Air resistance Rolling resistance Braking

Basic vehicle dynamics model for adequate engine simulation.

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Soft ECUs

puts are standard actuators. The soft ECU has an engine torque based controller concept for homogeneous and stratified engine operation modes.

Controller for ignition angle Controllers for fuel system Controllers for air system Angular processing unit

Control SoftwareThe included soft ECUs are needed in scenarios where a real ECU is not available, for example, offline simulation. A combination of soft and real ECUs can be used in HIL scenarios where real transmission ECUs are not available.

Components and Characteristics Engine operation detection Engine torque calculation Torque-to-injection quantity and torque-

to-relative-air-mass conversion

Gasoline Soft ECU The gasoline soft ECU is basic gasoline engine ECU controller software without any diagnostics, used for testing the engine model in closed-loop operation when no real ECU is connected. Its inputs are standard sensor signals and the out-

The Soft ECU provides controls for engine and transmission.

Transmission Soft ECU The transmission soft ECU shifts the gear of the automatic transmission according to the cur-rent driving situation and controls the torque converter and lockup clutch.

Components and Characteristics Automatic gear shifting Park, reverse, neutral, and drive mode Tip shift control supported Lockup clutch control Engine speed and accelerator pedal

included

The shift detection system of the transmission soft ECU.

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Environment RoadThe road subsystem allows environmental con-ditions like road slope, ambient pressure, and temperature to be set.

Components and Characteristics Slope Ambient pressure and temperature

ManeuverManeuvers define how a vehicle moves. Depend-ing on the maneuver mode, they either provide stimulus signals directly to certain vehicle compo-nents like ignition key, accelerator pedal, brake pedal, clutch pedal and gear lever, or give in-structions to a driver model, which controls the vehicle.

Components and Characteristics Manual control in offline mode (Simulink) Manual control in online mode using

ControlDesk Time-dependent, predefined stimulus

maneuvers Driver maneuvers (velocity profiles, for

example, FTP75, NEDC, J10-15)

Driver The driver model controls the vehicle. Its main task is to drive the vehicle at a desired velocity. The vehicle is controlled by accelerator pedal, brake pedal, clutch pedal and gear shifter.

Components and Characteristics Longitudinal controller for accelerator and

brake pedal, comprising feedforward and feedback control

Gear and clutch control for manual transmission

Velocity profile according NEDC. The engine model can be simulated in a complete environment, which is useful for longitudinal driving maneuvers.

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Technical Aspects

Signal Processing Mean Value ModelThe ASM engine mean value models use com-bustion torque modulation to calculate torque generation on a cylinder-selective, crank-angle-synchronous basis. The intake manifold dynamics, the friction torque, and the exhaust gas behavior are also simulated by mean value models. This guarantees optimum real-time performance.

Torque modulation can be considered as a form function applied to the mean value signals. It is calculated on a cylinder-selective, crank angle-synchronous basis.

Subsystem OversamplingTo guarantee numerically stable integration of submodels with stiff behavior (e.g. the ASM – Brake Hydraulics Model), local subsystem oversampling is used. The Simulink For Iterator subsystem evaluates stiff differential equations n-times during one major simulation step.

Subsystem oversampling for a step response of a first-order delay element.

Online Tunable Parameters Every parameter of the model can be tuned while the model is performing a real-time simulation on a dSPACE Simulator. Every parameter (vehicle mass, etc.) is implemented as a single constant block in the model. ControlDesk provides access to each parameter when the model is used in online mode.

Signal and Parameter Management

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ASMSignalBusThe ASMSignalBus comprises the relevant sig-nals of all model components in a hierarchical structure. Signals for I/O access with an interface

Signal and Parameter Managementboard or for display with a Simulink Scope can

be chosen conveniently via a Simulink Bus-Se-lector.

The ASMSignalBus provides a structured view of all the relevant signals.


The gasoline engine Simulink model with the main components and signals.

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The userinterface of the comprehensive parameterization tool.

ASMParameterizationParameterizing a model is a crucial task. To make it as efficient as possible, ASMParameterization provides semi-automated calculation of the mod-el parameters and look-up tables in MATLAB. Parameterization is based on measurement data and parameters – the number of cylinders, ve-hicle mass, etc. The GUI-based tool supports the loading of engine test bench measurements from Excel format, the mapping of measurements to

model variables including unit conversion, and automatic generation of look-up tables using several kinds of interpolation and extrapolation functions. These are open M-functions that you can modify as required. Last but not least, the tool provides structured access to model com-ponents and enables you to manage parameter sets for individual model configurations.

Signal and Parameter Management

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ASM Philosophy

ConceptModel Design PhilosophyFor optimum support of customer-specific re-quirements dSPACE has chosen an open model concept. This means that models are visible to users right down to the level of standard Simulink blocks. Thus the dSPACE Automotive Simulation Models provide enormous flexibility for projects that require dedicated simulation models. The open model approach allows perfect adaptation to individual projects and requirements. This can be achieved by modifying models or by replacing or adding components.

Virtual VehicledSPACE Automotive Simulation Models are a col-lection of well coordinated models that you can easily combine to build anything from extended models to a whole virtual vehicle. As well as gasoline and diesel engines, there are models for vehicle dynamics and brake hydraulics. Combined models interoperate in one simulation.

Several ASM packages can be combined to make up a virtual car.


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dSPACEwww.dspace.com

France

dSPACE Sarl Parc Burospace . Bâtiment 20 Route de la Plaine de Gisy91573 Bièvres CedexTel.: +33 1 6935 5060 Fax: +33 1 6935 5061 [email protected]

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Kanagawa-ken 240-0005Tel.: +81 45 338 3361 Fax: +81 45 338 3362 [email protected]

Headquarters in Germany

dSPACE GmbH Technologiepark 25 33100 PaderbornTel.: +49 5251 16 38-0 Fax: +49 52 51 6 65 29 [email protected]

asm – gasoline engine simulation package 6 automotive simulation models fuel system the fuel...

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