Transcript Document 7335786

The Application of HIL in Automotive
Powertrain Development
Sam Akehurst
EPSRC Advanced Research Fellow
Powertrain & Vehicle Research Centre
University of Bath
Lean Powertrain Development
Presentation Outline
• What is a Powertrain?
• Lean Powertrain Development
– Project Background, Project aim, Methods
• Where HIL fits in
• HIL Examples
– Virtual calibration
– Virtual components
– Virtual powertrain
• Real Time Engine Modelling
Lean Powertrain Development
What is a Powertrain?
• Sub-systems include
– Engine
– Transmission
– After-treatment
Systems
– Electronic Control
Units (ECU) and
Control Software
Lean Powertrain Development
Powertrain R&D - Current
Industry Practice
• Separate sub-system development process- Little
integration, compromised result
• Simulation tools used intensively, but at sub-system level –
Little integration to achieve optimisation
• New technologies selected off the shelf- Rarely optimised
for required duty
• Lead time to market compromised by multiple iterations
during development
Lean Powertrain Development
Project Aim
To develop an integrated approach to
Powertrain design, performance
optimisation and rapid calibration,
through a simulation and model
based philosophy
Lean Powertrain Development
Project Aim
Realism
Vehicle Test
Rolling Road
Advanced Engine Test
Basic Engine Test
Powertrain Simulation
Cost & Complexity
Lean Powertrain Development
Emerging Technology Issues
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Product Cost
Development cost
Over Specification, Technology Redundancy
Control & Calibration
Complexity
– Reliability
– Development time
• Cost and time to market
– Optimisation!
Software & Hardware Implementation
GAs
RTW
MBC Matlab
Simulink
Optimisation Tools
Virtual
Engine
Calibration
Vehicle & Transmission
Control
HIL
Reality
Powertrain
Specific HIL Projects
• Desktop Powertrain Calibration
• Prototype Component Emulation
– Turbocharging/ Air Handling
• Advanced Transmission Control and
Optimisation
Desktop Powertrain Calibration
• Virtual engine model interacting with production ECU
– Allows rapid calibration of production ECU for new engine/hardware
combinations
– Low cost, reduces expensive facility and experimental time
– Can be linked to optimisation routines and standard vehicle
manoeuvres to develop improved vehicle performance at an early
stage in product development
– New control strategies can be developed if existing strategy is
identified as insufficient
• Before expensive mistakes are made
– Software approach allows analysis of non-measurable or hard to
measure variables on engine
Engine Loom Interface
Fuel Injectors
Fuel Rail Pressure
Engine Knock Sensor
Engine Temperature
Cam Shaft Position Sensor
EGR & VGT Actuators
Crank Position Sensor
Rail Pressure Control Valve
Air Charge Temperature
Air Charge Pressure
PRODUCTION ECU
Mass Air Flow
Accelerator Pedal Position
Engine Loom Interface
Production
Engine Loom
ECU
Breakout
ECU
Calibration Tool
& interface
+ Optimisation
tools
Production
ECU
dSPACE HIL Simulator &
Associated Breakout
Virtual Prototyping New
Hardware
• Software based simulation of prototype
hardware
– turbocharger performance characteristics
• Novel emulating hardware interacts with
real world engine
– Combustion Air Handling Unit (CAHU) and
Exhaust Back Pressure Valve (EBP)
Engine Test Facility
Hardware - Current Engine Turbo Schematic
MASS
AIR
FLOW
(used as comparator to CAHU)
Tboost
INTAKE
C
pboost
EXHAUST
T
Pdownpipe
pback
Texhaust
Tpre-valve
(TURBO SHAFT)
Hardware – CAHU Schematic
MASS
AIR
FLOW
Tboost
CHARGE AIR
HANDLING UNIT
INTAKE
IN-CYLINDER
PRESSURE
MEASUREMENT
pboost
INDUSTRIAL
COMPRESSOR
EXHAUST
Pdownpipe
pback
Texhaust
Tpre-valve
BOOST
‘DRAIN’
VALVE
BACK PRESSURE
VALVE
TURBO MODEL
on dSPACE Platform
CP CADET
Control & Data
Acquisition
System
(Includes Safety)
Air Handling System Emulation
• Reverse Engineering
– Turbocharger characteristics can be derived from
engine performance requirements
• Concurrent development of control strategies and
interactions with other engine systems
• Emulating system can describe many iterations of
prototype hardware
– Turbocharger, supercharger, electric assist systems
Hardware – Turbo Model
• Turbo model is dependant upon the
phase of the project:• Phase 1 – Simple look up tables in Simulink
turbine and compressor performance maps.
Model of shaft torque balance. Simulate
existing turbocharger
• Phase 2 Simulation of small HP turbine and
how it interacts with existing turbocharger
(pulsation effects)
• Phase 3 Simulation of full two stage
turbochargers and superchargers- Torque load
applied to engine by dynamometer
Complete Powertrain Testing
• Virtual Vehicle and Engine
• Real world hardware
– transmission and transmission control
systems
• Model set-points and feedback signals
transmitted on CAN bus to dyno control
system
• Inverted model of dyno response
Complete Powertrain Emulation
Complete Powertrain Emulation
CAN BUS COMMS
ATI Vision Calibration Tool
Real Time Models, Driver
& Inverse Response
Model of E-machines
Matlab MBC and
Optimisation Tools
Output Motor Emulates Vehicle
Input Motor Emulates Engine
CP CADET
Control & Data
Acquisition
System
(Includes Safety)
Real Hardware is Transmission
and control systems
Drive Cabinets/Common DC bus
Real Time Engine Modelling
• Generally a compromise
– Speed of execution vs. model fidelity
• Range of Models Available
– Crank angle resolved (highest fidelity)
– Mean Value (resolved once per engine cycle)
– Response Surface Engine models
Real Time Engine Modelling
• Crank Angle or Time based simulation?
– Resolve to crank angle for cylinders
– Mean value model for manifolds/ gas dynamics
• Pre calculate as much as possible
– Populate look-up tables where possible
• Model one cylinder and “phase shift” others
• Analytical models
– Identify areas of importance for chosen work
• Statistical models derived from offline data fits
(experimental or code generated)
– Polynomials
– Multidimensional
Response Surface Engine Models
Experimental
Design
Experiments
Build Models
Cycle Simulation
Classical
or Space
Filling
Designs
Polynomial Models
Neural Networks
Radial Basis Functions
Engine Test
Historical Data
“One Click”
Simulink Model
Block
Software - Ricardo WAVE
AMBIENT
PRESSURE & TEMP
MAF SENSOR
AMBIENT
PRESSURE & TEMP
EXHAUST DOWNPIPE
THERMOCOUPLE
JUNCTION
COMPRESSOR
INJECTOR
CYLINDER
EXHAUST
EGR SENSOR
INTERCOOLER
VGT
ACTUATOR
TURBINE
DUCT
INTAKE
ORIFICE
EGR ACTUATOR
Software – Model Based Calibration
SIMULINK BLOCK
CREATED FROM MODEL
IN SINGLE MOUSE CLICK
Software – Calibration Generation
MAX CYLINDER
PRESSURE<180bar
NO CONSTRAINTS
EXHAUST TEMPERATURE<1033K
Viewing Trade-Offs and Finding Optima
Any Questions?