Root Locus Bode Plot Ref. Voltage + - + Ref. - Speed Controller Controller Real Axis Frequency Modeling a Hybrid Electric Vehicle and Controller to Optimize System Performance 2005 The MathWorks, Inc. Steve Miller Technical Marketing, Physical Modeling Tools The MathWorks GmbH, Munich, Germany Steve.Miller@mathworks.de
Key Results 1) Integrating the requirements in model and simulation is critical for effective development 2) Effective use of control design tools and optimization algorithms improves overall design 3) Simulating plant and controller in one tool allows engineers to understand and optimize performance of the entire system Root Locus Real Axis Bode Plot Frequency 2
Agenda Introduction to HEV Model 5 min Improving Development Process 5 min Linking Design and Specification Comparing Performance and Specification Optimizing HEV System 15 min Linearized Model Nonlinear Model Questions and Answers 5 min 3
System Optimization Challenge HEV with two PI controllers Speed Controller, Voltage Controller Must meet performance requirements Conflicting goals Improving speed response degrades voltage bus response 4 Command Voltage DC-DC Converter Duty Cycle Bus Voltage Controller + - Command Speed Command Torque Vehicle Speed Controller + -
HEV Electromechanical System Battery SimPowerSystems Simulink Braking Chopper Three-Phase Bridge SimPowerSystems Simulink SimDriveline Simscape SimPowerSystems Simulink 5
Simscape Extension of Simulink designed to model multidomain physical systems Eases process of modeling physical systems Does not require deriving and programming the equations of motion for the system Used by system engineers and control engineers to build a model representing the physical structure of the system T A P B SimPowerSystems SimMechanics SimDriveline SimHydraulics Simscape MATLAB, Simulink T V+ V- 6
Electrical System in SimPowerSystems Permanent Magnet Synchronous Motor Drive Speed controller Vector controller Inverter Permanent magnet synchronous motor Braking chopper Implemented through SimPowerSystems in the Simulink environment SimPowerSystems Blocks 7
Mechanical System in SimDriveline Transmission System Input Torque Transmission Vehicle Inertia Implemented in SimDriveline within the Simulink environment Input Torque Transmission Vehicle Inertia Wheel Speed SimDriveline Blocks 8
Agenda Introduction to HEV Model 5 min Improving Development Process 5 min Linking Design and Specification Comparing Performance and Specification Optimizing HEV System 15 min Linearized Model Nonlinear Model Questions and Answers 5 min 9
Linking Specification and Design Situation: HEV Requirements 1. Drivetrain System Layout Part Numbers Problem: Matching design to specification is difficult. Solution: Use Simulink Verification and Validation to directly link the design to the specification. 10
Comparing Specification and Design Situation: HEV Requirements 1. Drivetrain System Wheel Speed 5% Setting Time in 0.5 Sec Problem: Measuring design performance relative to specification is difficult. Solution: Use Simulink Verification and Validation to automatically compare performance to specification. 11
Improved Development Process Advantages of improved process 1) Enables quick and easy associaton of specification and model 2) Automatically checks design against specification 3) Supports Model-Based Design, helping you discover and solve problems earlier in the design process 12
Agenda Introduction to HEV Model 5 min Improving Development Process 5 min Linking Design and Specification Comparing Performance and Specification Optimizing HEV System 15 min Linearized Model Nonlinear Model Questions and Answers 5 min 13
Possibilities for System Optimization Linearized model Linearize system via Simulink Control Design Perform linear control design with Control System Toolbox and Simulink Response Optimization Retest in nonlinear system + - Controller Nonlinear model Specify response characteristics Automatic tuning via Simulink Response Optimization + - Controller A x + B u Root Locus Bode Plot Real Axis Frequency 14
System Optimization On Linear Plant Model: Ref. Voltage + - + Ref. - Speed Controller Controller Problem: Design and tune the two controllers in this system to meet system requirements. Solution: Use Simulink Control Design, Control System Toolbox to design, tune, and test the controller 15
System Optimization On Linear Plant Steps to Design Controller 1) Identify control loops of interest 2) Identify operating point Command Voltage Command Speed + - + - Controller Controller Bus Voltage Vehicle Speed 3) Linearize model about this point A x + B u = 0 4) Perform control design 5) Test controller in nonlinear system Root Locus Real Axis Bode Plot Frequency 16
System Optimization On Linear Plant Advantages of Simulink Control Design 1) Enable easy application of linear control theory Operating points from specification or simulation Graphical design with interactive plots 2) Rapid evaluation of designs with interactive analysis plots 3) Optimize performance based on time, frequency, or root locus constraints 17
System Optimization On Nonlinear Plant Model: Ref. Voltage + - + Ref. - Speed Controller Controller Problem: Design and tune the controller in this system to meet system requirements. Solution: Use Simulink Response Optimization to design, tune, and test the controller (K p s+k i ) s Voltage (K p s+k i ) s Speed Voltage Speed Motor K p K i K p K i R 0.001 0.003 0.005 0.006 0.007 0.033 0.023 0.014 0.001 3.0 2.2 1.9 1.5 1.3 62.8 75.1 83.9 95.7 120 0.08 0.07 0.06 0.05 18
Control Design On Nonlinear Plant Steps to Optimizing Response 1) Identify parameters to be tuned and their ranges (K p s+k i ) s 2) Specify desired response 3) Perform response optimization 19
Control Design On Nonlinear Plant Advantages of Simulink Response Optimization 1) Simulating plant and controller in one tool allows engineers to understand and optimize performance of the entire system 2) Automatic tuning of parameters saves time 3) Graphical interface makes it easy to map specification to tests 20
Summary 1) Integrating the requirements in model and simulation is critical for effective development 2) Effective use of control design tools and optimization algorithms improves overall design 3) Simulating plant and controller in one tool allows engineers to understand and optimize performance of the entire system Root Locus Real Axis Bode Plot Frequency 21
Agenda Introduction to HEV Model 5 min Improving Development Process 5 min Linking Design and Specification Comparing Performance and Specification Optimizing HEV System 15 min Linearized Model Nonlinear Model Questions and Answers 5 min 22
MathWorks Physical Modeling Tools Booth (HEV Example, Other Tools) Series-Parallel architecture using Simscape, SimDriveline, SimPowerSystems 23
Physical Modeling Master Class (Wednesday, 10:30 12:00) Model and simulate multidomain physical systems all within the Simulink environment Optimize system performance by developing the plant and controller in one environment s1 s3 s2 Use Model-Based Design on your entire system to improve your development process Simulink Plant Model Production C-Code 24
Thank You For Your Attention! 2005 The MathWorks, Inc. Steve Miller Technical Marketing, Physical Modeling Tools The MathWorks GmbH, Munich, Germany Steve.Miller@mathworks.de