Plant Modeling for Powertrain Control Design Modelica Automotive Workshop Dearborn, MI

1. Plant Modeling for Powertrain Control Design Modelica Automotive Workshop Dearborn, MI November 19, 2002 Dr. Larry Michaels GM Powertrain Controls Engineering

2. Control System Design starts late Rush to develop algorithm and write code Minimum opportunity to influence hardware Sensors & actuators may already be determined Cost is always a major factor Challenges in PT Control Design

3. Model-Based PT Control Design Process Control Strategy Enhancements Existing Algorithm Models SSTS Powertrain Design PT Plant Models CTS Sensor/Actuator Design Control System Architecture Design Testing & Calibration Control System Conceptual Design Concept CTR Controller H/W Engineering ADD Software Engineering System Engineering Analysis Control System Design Algorithm Models Plant Models Diagnostic models Other Deliverables Calibration Methods Test Scenarios Test Calibrations RPC to validate concept Software New Ideas Implementation Issues Elaborated algo model Refined PT models Sensor/Actuator models Diagnostics Calibration Procedure Cost models Robustness HWIL tests (Simucar) Calibration Procedures Use models to understand algorithm Validate S/W vs. algo. model Software-in-the-loop tests

4. Control Algorithm Design Process Analyze and Choose Control Theory Build Plant Control Design Model Build Plant Model Calculate Control Algorithm Build Algorithm Model

5. Plant - physical system that is a major PT element of interest in a control problem, e.g., engine, transmission, EGR subsystem. It typically includes actuators, sensors, controller circuitry, wiring and environment Plant Model - physics-based or behavioral math model built to understand the problem and represent the dynamics of the system being controlled Plant Control Design Model - simplified plant model used to develop control algorithm via Control Theory, usually linearized model, possibly created from experimental data (System Identification) Algorithm Model - executable representation of an algorithm - equations, data flow diagram, state charts Types of Models

6. Plant models may take long to develop Many different models needed Problem dependent Fidelity and complexity No standard plant model architecture Need to validate model vs. hardware Desire to reuse models Different tools being used Sensors, actuators, signal delivery system important Plant Modeling Issues

7. Powertrain Control System Block Diagram Powertrain Engine and Transmission Controller Hardware and Software Actuators Sensors Instrumentation Service Tools Platform Interface Assembly Plant

8. Controller Hardware & Software ECM or TCM Crank Sensor Throttle Position Coolant Temp O2 Sensor Input Circuits and HWIO Compute Engine Output Circuits and HWIO Force Motor Injectors Ignition signals Fuel Pump On/Off High Side Pulse Width Modulated On/Off Low Side Operating System Application SW HWIO SW Math Library A/D Converter Pulse Counter Frequency measure

9. Specific model for problem-at-hand One-size-fits-all model Reconfigurable models for levels of complexity Causal vs. a-causal models Data flow diagrams Topological models Plant Modeling Strategies

10. Co-simulation with other tools detailed engine & transmission models algorithm models sensor & actuator models calibration tools Capable of real-time simulation for HIL Support for various levels of fidelity e.g., model order reduction Modular structure Easily validated and correlated Plant Modeling Tool Requirements

11. Compatible with CM and version control tools Support for libraries Parametric configuration facilities Enterprise support documentation, readability, portability Supports software-in-the-loop Scripting capability Web interface Plant Modeling Tool Requirements