automotive powertrain controls: fundamentals and frontierscset.mnsu.edu/tcac/acc05_jcook2.pdf · 3...

12005 American Control Conference

June 8-10, 2005, Portland, OR.

Automotive PowertrainControls: Fundamentals and Frontiers

Jing SunDepartment of Naval Architecture and Marine Engineering

University of MichiganAnn Arbor, MI USA

Julie BucklandResearch & Advanced Engineering

Ford Motor CompanyDearborn, MI USA



TopicsModeling and Control of Automotive Powertrain Systems: A Tutorial, Jing Sun (UM), Ilya Kolmanovskyand Jeff Cook (Ford Motor Company)Challenges and Opportunities in Automotive Transmission Control, Zongxuan Sun and Kumar Hebbale, General Motors Corp. Automotive Emissions Control, Julia Buckland and Jeff Cook, Ford Motor Company Towards a Concurrent Engine System Design Methodology, Akira Ohata and Ken Butts, Toyota Motor Corp.



Modeling and Control of Automotive Powertrain Systems

Introduction and motivation: Models, methods and issues (Jeffrey Cook)Gasoline direct injection engine control (Jing sun)Diesel engine control (Ilya kolmanovsky)



History: Electronic Powertrain Controls

Emissions-driven technology development1980s: Decade of controls1990s: Decade of systems2000s: Complexity and sustainable mobility



Constraints: Fuel Economy and Performance

Europe: 140 g/km CO2 by 2008 (25% reduction compared to 1995 baseline)US (Federal): 27.5 mpg CAFEUS (California): Air Resources Board to write rules curbing carbon dioxide and methane emissions starting with the 2009 model yearEverywhere: Customers



Four Stroke Otto Cycle Engine



Sensors and Actuators

Powertrain controller32-bit MPC55xx, ~150 pin I/O connector; ~90 control features

SensorsAir flowExhaust O2 or A/F (2-3 places)Intake manifold pressureCrankshaft and camshaft position (engine speed)Throttle positionFuel rail pressureEGR position or delta PressureKnock (accelerometer)

SensorsTemperature (air, intake and exhaust manifold, engine coolant, catalyst bed)Accessory loads (A/C clutch compressor sensor, battery voltage, power steering pump)Potentially ionization, in-cylinder pressure, emissions sensors (NOx)



Sensors and Actuators

ActuatorsThrottleAir bypass valveFuel (pump, pressure regulator, injector timing and duration),IgnitionEGRCamshaft phase (intake and/or exhaust)WastegateSecondary airCanister purgeCharge motion controlIntake manifold tuning

Actuators (potentially)Valve lift, Cam profile switchingElectronic valve actuationCylinder deactivationVGTVariable compression ratioIntegrated starter-alternator Clutched superchargerTraction motor



ThrottleIntake manifold dynamicsEngine pumping and intake valve flowTorque generationRotational Dynamics

Basic Engine Model

Exhaust manifold dynamicsAir and fuel path delaysFeedgas emissionsTWC (including dynamics)Sensor and actuator dynamics (throttle, VCT, turbocharger, etc.)



Basic Engine Model

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Manifold Pressure

Flow Equations

Cylinder Air Charge

Torque and Rotational Dynamics



Conventional Aftertreatment Systems

“Three-way” catalytic converterNarrow “window” of high simultaneous conversion efficiencyConventional control objective is to regulate A/F to stoichiometry



HEGO Sensor

Potentiometric Electrochemical sensorElectric potential related to oxygen partial pressureStandard on all US vehicles since 1980Essentially a switch



UEGO Sensor

Switching-type sensor with additional electronicsAmperometric sensor measures current proportional to oxygen partial pressure (lean) or hydrocarbon partial pressure (rich)



Closed-loop A/F Control

Estimate cylinder air charge (including EGR)Schedule fuel to achieve stoichiometry Use HEGO/UEGO feedback to compensate for uncertainties

But …Accuracy in air charge estimationTransient fuel dynamicsLimited feedback information when using HEGOTransport delayInjector variabilitySensor variabilityDisturbance inputs(vapor purge)



Transient Fuel Dynamics

Not all fuel injected gets into the cylinderSome fuel stays in the intake port and forms a puddle on the wall Fuel from puddle inducted in subsequent fueling events, causing AFR transient



Electronic Throttle Control

Inner-loop control: move the mechanical plate to the desired positionOuter-loop control: to command the ETC position to provide the desired air flow

But …Inner loop:

Highly nonlinear with significant friction and hysteresisResolution requirements at closed throttleChoked flow is sensitive to ambient pressure

Outer loop:Inverse orifice equation for throttle position control is almost singular at WOT



Other Powertrain Control Problems

Idle speed controlVariable cam controlEGRAir charge estimationShift scheduling and controlEvaporative emissions controlIgnition controlCold start controlsCatalyst temperature controlTorque control (electronic throttle)

Fuel pressure controlMisfire detectionCatalyst diagnosticsCruise controlTurbo/supercharger controlKnock detectionMisfire detectionSecondary air controlCylinder deactivationTorque converter lock-upFlex/fringe fuel detection



Fuel Economy Technologies

Improved mechanical efficiencyImproved thermal efficiencyReduced pumping loss

automotive powertrain controls: fundamentals and frontierscset.mnsu.edu/tcac/acc05_jcook2.pdf · 3...

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