REAL-TIME HARDWARE-IN-THE-LOOP SIMULATION FOR DRIVABILITY DEVELOPMENT

Yun Liu, Sung Kwon Hong, Tony Ge

Ford Motor Company

dSPACE Technology Conference

October 18, 2017

Plymouth, MI, USA

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Agenda

� Introduction∗ Drivability development challenges and HIL approach

� Drivability HIL Simulation Requirement∗ Drivability Hardware-in-the-loop simulation approach∗ Vehicle CAE model requirement∗ HIL hardware requirement

� CAE Models and HIL Simulation Process∗ Multi-disciplinary CAE plant models ∗ HIL simulators and powertrain controller module (PCM) interfaces setup∗ Drivability HIL test process and result

� Summary

� Acknowledgements

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Introduction

� Drivability is a measure of vehicle capability to achieve desired response to driving events. The response is mainly related to longitudinal acceleration of the vehicle.

� Examples of drivability phenomenon

* Tip-in / Tip-out* Gear Change* Start-up / Shut-down

� Smooth and controlled transient is expected as entire vehicle dynamical system responds to changing driver, controller or environment inputs.

� Objective drivability evaluation tools can quantify the transient behavior and is becoming a standard vehicle calibration sign-off procedure

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Drivability Development

� Vehicle system interaction

∗ Powertrain and chassis hardware

∗ Control strategy

∗ Driver interfaces

� Challenges of drivability development

∗ Evaluation and calibration usually happens on prototype vehicles

∗ Physical tests are associated with considerable time and resource cost

∗ Design change options are limited and expensive in late product development cycle

∗ Early design phase methods do not address the problem comprehensively

∗ Closed-loop interaction between vehicle system and controller not represented well

� Model based system engineering approach

∗ Process goal: evaluate drivability with full vehicle CAE models and complete control strategy

∗ Provide analysis tool to component and control design before committing to hardware

Drivability

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Drivability HIL Simulation Process

� HIL drivability development cycle

∗ Simulate vehicle systems CAE model with controller in the loop

∗ Capture system dynamics response in drivability event

∗ Correlate and evaluate results

∗ Apply component or control strategy design change to improve drivability attribute

∗ Start next simulation and design change iteration

HIL Simulation

Drivability Transient Capture

Result Evaluation

Design Change

Design iteration is more efficient in HIL simulation

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Drivability HIL System Requirement

Technical requirements of HIL

� Key enabling technology: Vehicle CAE models

∗ Degrees-of-freedom and accuracy to capture drivability transient frequency range (below 20-30 Hz)

∗ Mostly physics based for transient state change, not steady state map

∗ Powertrain models tightly coupled with controller

� CAE model and controller integration: HIL simulators and IO hardware

∗ High performance computing platform with multi-core parallel processing

∗ High speed inter-processor data sharing architecture

∗ IO signals drivers for data exchange between CAE models and powertrain control module

CAE Model Real Time Simulator PCM

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Multidisciplinary CAE Model Setup

� CAE modeling tools selection

∗ Represent vehicle behavior in the required frequency range

∗ Efficient real time solver to execute on available HIL simulator targets

∗ Existing experience, building time, maintenance cost

� Solution example for a target vehicle

∗ Ricardo WAVE-RT 2.0L engine plant model in thermal fluid physics domain

∗ GT-SUITE 6 speed transmission mechanical and electrohydraulic plant model

∗ SIMPACK multi-body dynamics vehicle chassis model: mechanical and high DOF

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Real Time Engine Model

� Real time engine models in HIL

∗ Mean value engine models are extensively applied in HIL but limited to cycle average torque

∗ To represent torque transient in the required frequency band, a crank-angle resolved and cylinder independent engine model will meet the goal

� Drivability HIL engine model

∗ Target engine is turbo charged 2.0L 4-cylinder gasoline with direct fuel injection.

∗ Detailed 1-D WAVE engine model is simplifiedand exported to WAVE-RT as standard C codeand S-function

∗ The WAVE-RT model simulates 1-D air path and crank angle resolved torque from individualcylinder

Engine torque pulses with 0 crossing between cylinder combustion cycles

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Transmission driveline CAE Model

� Target application: 6 speed automatic front wheel drive∗ Torque converter model and lock-up clutch∗ Gear shift clutches and hydraulics circuit ∗ Gearbox, shaft and axles

� Integrated GT-SUITE transmission plant model∗ Full driveline analysis model in multi-physics

domain with nonlinear components∗ Improved library components and

real time solver in latest release and real-timecapable on newer simulator target.

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Vehicle Chassis and Tire MBD CAE Model

� Multibody dynamics for drivability

∗ 3D Tire components

∗ Powertrain and chassis body

∗ Mounts, suspension, bushings

∗ Need a higher DOF model than commonvehicle motion dynamics simulation

� Real time SIMPACK MBD model

∗ 159 DOFs white box physical model

∗ No code generation or compilation required

∗ Real time solver execution directly on Linux OS

∗ Built-in parallel computing on multiple cores

Real time task viewer of MBD vehicle model solver

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HIL Simulators System Configuration

� HIL Hardware interacts with model simulation and affects CAE performance

� HIL Simulators∗ High performance multi-core computers with real-time OS∗ I/O device drivers to emulate sensors, actuators, network and bus signals∗ HIL user interfaces and test environment∗ Drivability HIL simulators: dSPACE DS1006, SCALEXIO, Concurrent Real Time Linux workstation

� I/O boards between plant model and PCM∗ Automotive sensors, encoders∗ Current, voltage measurements∗ CAN/LIN/Ethernet interfaces

� HIL host computer∗ Test environment with real time simulator interfaces∗ PCM calibration tool interface

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HIL Simulation: Integrity Test

� Verify CAE models are integrated correctly with control strategy

� HIL signals connection validation∗ Component plant model physical signals

∗ Controller signals wiring and conversion to plant model

∗ PCM diagnostics code history

� Standard drivability test sequence checkoutbasic plant model and PCM state variables

� Complete integrity testcompare all model and PCM variables like engine air flow, temperatures, clutch pressure, acceleration.

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HIL Simulation: Drivability Events in Detail

Drivability events are usually transient behavior

Tip-in with slipping torque converter clutch Gear Shift

Transient states: air pressure, fuel flow, torque, speed, vehicle accel, clutch pressure, … Control and calibration: throttle, injector, spark, VCT, waste gate, slip, gear, command pressure, PWM currents,… Model Parameters: air path, inertia, stiffness, converter map, clutch friction, hydraulics volume and preload, …

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Summary

� This work applies HIL method to powertrain drivability attribute development.

� CAE models, controller module and HIL simulation tools are integrated and results show the technical possibilities and potential application process.

� HIL approach is a feasible method for drivability development. There are many benefits shifting vehicle tests to virtual simulation.

� Future deep integration with product development process to be implemented with long term process improvement goals

∗ Standard real-time CAE models

∗ Automated HIL test procedures

∗ Optimization tools to drive such procedures

component models, controls,

calibrations

HIL integration

Drivability Dev Process

Thank You!QUESTIONS?

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