Model-Based Design and Hardware-in-the-Loop Simulation for Clean Vehicles Bo Chen, Ph.D. Dave House Associate Professor of Mechanical Engineering and Electrical Engineering Department of Mechanical Engineering - Engineering Mechanics Department of Electrical and Computer Engineering Michigan Technological University July 4 th, 2013 1
Outline of Presentation Background and Motivation Model-Based Approach for Embedded Control System Design Hardware-In-the-Loop (HIL) Simulation Single Shaft Parallel Hybrid Electric Vehicle (HEV) and Electronic Control Unit (ECU) Network HIL Simulation of Parallel HEV Conclusions 2
Background and Motivation Vehicle Population 750, 000, 000+ vehicles in the world Expected 2 billions by the year of 2020 Fuel Consumption The transportation sector in the U.S. accounts for two-thirds of our petroleum use Environmental Emission Transportation produces 33% of US CO2 output Fuel Economy & Emission Standards Technologies & Challenges Hybrid, electric, fuel cell, and renewable energy vehicles Complex powertrain and control system 3
Model-Based Approach for Embedded System Design Conventional V-model: a plan-driven process. The design process follow the defined development stages in order Model-based Design: provide an integrated environment for design, simulation, automatic code generation, and validation. 4
Salient Features of Model-Based Embedded System Design Approach Platform for representing entire system: control strategy and plant models Graphical representation: use graphical language to describe implementation details Time saving: minimize software development time and maximize software re-use. No hand coding, production quality code is automatically generated Integrated development and validation cycles Communication among the team members is made easier 5
Hardware-In-the-Loop (HIL) Simulation Electronic Control Unit Signal Conditioning Microcontroller Output Drivers MotoTron Engine ECU MicroAutoBox Motor ECU Generate an environment where ECU assumes that it is running with a real physical system. Sensors Electrical Signal Interface Actuators Automotive Plant Model Real World dspace HIL Simulator HIL System HIL simulator simulates the physical system that is under test. It generates plant sensor signals and capture actuator signals from ECU. Used to test control strategies to be implemented on ECUs. 6
dspace HIL I/O Interface PHS-Peripheral High Speed 7
Model Development and HIL Simulation Process Model Development Parameterization Updating Model Auto-code Generation Recording Online Calibration Downloading to ECUs Colors indicate the different softwares used in the steps. Blue : Simulink/Stateflow/dSPACE blocksets/real-time Workshop Model building, modification, and auto-code generation Yellow : dspace ModelDesk Model Parameterization Red : dspace ControlDesk Next Generation Real Time Calibration, Data Recording, File Export 8
Single Shaft Parallel HEV Powertrain Architecture and ECU Network Driver Engine ECU Hybrid ECU Motor ECU Environment Transmission ECU Vehicle level ECU: Hybrid ECU ICE Battery Clutch1 PMSM Inverter Clutch2 Gearbox Final Drive Low level ECU: Engine ECU Motor ECU Transmission ECU Automatic Transmission 9
dspace Parallel HEV Model From MotoTron ECM: Ignition angle Injection angle and duration Throttle valve, EGR valve, pressure control valve position, and PWM control signal From MicroAutoBox II: Three phase PWM signals Actuator Signals From RTI Blocks Actuator signals from ECU Sensor signals from ECU To RTI Blocks To MotoTron ECM: Engine torque request Engine speed Engine keys Intake manifold pressure and temperature Coolant temperature Rail pressure To MicroAutoBox II: Motor Torque Request Motor Speed Three phase current DC bus voltage Sensor Signals dspace 10 HIL Simulator
Parameterize HEV Model Using ModelDesk Environment Drivetrain Engine Vehicle Dynamics 11
HIL Setup for the Parallel HEV dspace HIL simulator MicroAutoBox II for motor controller MotoTron 128 pin ECM for engine controller 12
Vehicle Reference Speed Actual Vehicle Speed Shifting Maneuver Driver Controller APP BPP ICE Torque Request, Key Engine Controller MotoTron Vehicle Key Motor Torque Request Simulated Engine Sensor Signals Engine Actuator Signals Signal for the Parallel HEV Gear Level, Clutch Command Hybrid ECU HIL Simulator Transmission ECU SOC, Transmission Speed, Current Gear Level, Engine State Mechanical Brake Torque Request Motor Speed, 3 phase current, DC bus voltage Simulation Models PWM Signals Measurable Engine Signals Motor Torque Request, Motor Speed, 3 phase current, DC bus voltage PWM Signals Gear Ratio, Clutch Command Vehicle Plant Captured Engine Actuator Signals Motor Controller MicroAutoBox II Signals between Engine Controller and Vehicle Plant Sensor signals: AFM through throttle engine speed intake manifold pressure and temperature EGR valve position coolant temperature injection pressure Actuator signals: Ignition angle and duration injection angle and duration throttle valve, EGR valve, and pressure control valve position PWM control signal 13
Hybrid ECU Vehicle operating mode control Split powertrain torque between engine and electric machine to achieve maximum fuel economy Control regenerative braking to recover as much energy as possible and ensure braking performance at the same time SOC<Min_SOC or T_Bat>Max or TrqRequest>MaxMotorTrq Engine Only T_Bat>Max Electric Only T_Bat<Max Battery Charging SOC>Max_SOC and T_Bat<Max and TrqRequest<MaxMotorTrq SOC>Max_SOC SOC<Min_SOC Hybrid BPP>0 APP>0 Regenerative Braking 14
Vehicle Mode and Energy Flow (a) (c) (b) (a) Electric only mode (b) Battery charging mode (c) Engine only model (d) Hybrid mode. (e) Regenerative braking mode (d) (e) 15
Overview of Engine ECU Engine Speed Starter switch Ignition switch Engine Operation Engine State λ setpoint Rail Pressure ṁ throttle Homogenous Mode Injection Signals Spark Signal Throttle position Injection signals Ignition signals Intake Pressure Intake Temperature Relative Airmass Relative Airmass Rail Pressure ṁ throttle Stratified Mode Injection Signals Spark Signal Throttle position Throttle position Turbocharger control signal Engine State Coolant Temperature Engine Torque setpoint ENGINE ECU SUBSYSTEMS Engine Torque Setpoint Combustion Mode Switch Engine Torque Intake Pressure Ambient Pressure EGR % Rail Pressure Mean Injection quantity setpoint Airpath Rail Pressure Control Angular Processing Unit Turbocharger Control Signal EGR Control Signal Fuel Metering Unit Pressure Control Valve Cylinder wise Crank angle EGR control signal Rail pressure control signals Engine position 16
Motor Controller 17 17
dspace Experiment Software - ControlDesk 18
Simulation Results: Vehicle Mode Control # Vehicle Mode 0 Battery charging 1 Engine only 2 Hybrid mode 3 Motor only 4 Regenerative breaking Hybrid ECU control logic is modified to avoid frequent mode change. Improved vehicle performance is shown in enlarged subfigures. Vehicle operation modes in UDDS drive cycle 19
Simulation Results: Power and Energy Distribution P F req F x = ma = FT Froll FWd FGf = F v = ( ma + F + F + F ) v T mg roll Wd 2 roll = cosθ f r FWd ρcd Av Rolling resistance 1 = F Gf = mg sinθ 2 Wind drag Gf Gravitational force Vehicle power request, rolling resistance power, and wind drag power over a UDDS drive cycle 20
Simulation Results: Regenerative Breaking Designed to recover as much as possible Disabled when v < 0.1 km/h or SOC reached charging limit Power(kW) 0-5 -10-15 -20-25 Limited by maximum motor power 81% braking energy was recovered, total 0.4638 kwh -30-35 -40 Total Braking Power Regenerative Braking Power -45 0 100 200 300 400 500 Time(s) Braking power in US06 drive cycle 21
Simulation Results: Engine States State value 1 2 3 4 Engine state Idling Engine Traction only Traction & charging Battery Traction with motor 100 5 Vehicle Speed (km/h) 80 60 40 20 4 3 2 1 Engine State Engine On Engine idling 30.8% 53.3% Engine states in UDDS drive cycle 0 0 200 400 600 800 1000 1200 1400 0 Time(s) 22
Simulation Results: Engine Operating Region Engine operating points: HEV (left), conventional vehicle (right) Motor provides traction when torque demand below 100 Nm. 300 BSFC Speed Torque Map 280242 300 BSFC Speed Torque Map 250 900 800 250 242 900 800 Torque (Nm) 200 150 100 318 261 299 700 600 500 Torque (Nm) 200 150 100 700 600 500 50 394 432 356 idling motor 400 300 50 400 300 0 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Engine speed (rpm) 0 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Engine speed (rpm) 23
Conclusions Model-based design allows ECU development with vehicle plant models in the same environment. Hardware-in-the-loop simulation enable very short development times with parallel control system validation. Model-based design HIL simulation are suitable for the development of complex control systems for the clean vehicles. 24
Acknowledgements This research is supported by the National Science Foundation under Grant NO. OISE-1157647. Laboratory of Intelligent Mechatronics and Embedded Systems Michigan Technological University http://me.sites.mtu.edu/chen/ 25