Engine Calibration Process for Evaluation across the Torque- Speed Map

Transcription

1 Engine Calibration Process for Evaluation across the Torque- Speed Map Brian Froelich Tara Hemami Manish Meshram Udaysinh Patil November 3, 2014

2 Outline : Background Objective Calibration process for torque speed map Steady state calibration results Transient simulation using Fast Running Model Summary 2

3 Background Information : Torque DoE Design IV Engine Speed Test Cell Optimization ~1000+ pts Testing Process ~200 to 400 pts 2500 pts Simulation Approach Simulation Steady State Transient New controls strategies

4 Background Information : Torque (N-m) All test points Selected test points Speed (RPM) Test engine at limited points. Calibrate engine at limited operating points GT-Power model to predict engine performance across entire torquespeed map. 4

5 Overall Process : Test Plan to collect data for model calibration and validation Modify GT- Power model Engine Pre-Test work complete; Targets, Constraints and Levers identified; Parent GT Power Model identified Run Engine ~ 200 to 400 Points Combine data Data for optimization for MLR Modeling Optimization CyberCal Process Studies Calibrate GT- Power model Validate GT- Power model Correct for bias in model predictions NO Model ok to use for further for Cal Development? studies? YES Run full space fill for GT-Power models GT Conference 2014

6 Process development workflow : ~ 200 to 400 Points Test Cell Data Detailed GT-Power model with the correct geometry ~ half of selected Points Calibration Data Calibrate standalone Subsystems Combine the Subsystems into the whole engine model Subsystem models Intake system Compressor Charge Air Cooler Intake manifold + Cylinder + Exhaust manifold EGR Loop Turbine Exhaust system ~ half of selected Points Validation Data Check the model with test cell data Check the model with Validation data Goal Engine performance parameters within error bars. (torque, flow, pressures, temperatures) Calibrated GT-Power Model 6

7 Model calibration : (Standalone Subsystem level calibration) Calibrate standalone system models like turbochargers, after cooler etc. Calibrate within error limits Intake restriction subsystem with imposed boundary conditions Intake restriction Air flow rate Develop a correlation of intake restriction diameter and air flow Simulation Experimental Predicted performance within +/-3 % error band Example: Calibration of standalone intake restriction model 7

8 Model calibration (Integrating Subsystem models together) Integrate the well calibrated subsystem models Comp out Pressure Turbo speed Intake system Simulation Simulation Turbocharger Experimental Experimental Example :Integrating intake system and turbocharger model The independently calibrated intake system and turbocharger coupled together.

9 Observations Experimental vs Simulation : Torque Air flow rate GIMEP NIMEP Predictive GT-Power combustion model used for predicting performance across entire torque speed map GT Conference 2014

10 Observations Experimental vs Simulation Peak Cylinder Pressure Intake Manifold Temp Turbine Inlet Temp Turbocharger speed Predictive GT-Power combustion model used for predicting performance across entire torque speed map GT Conference 2014

11 Observations Experimental vs Simulation : GT-Power predictions for operating points. 11

12 Transient Cycle Calibration using GT-Power 12

13 Transient Requirement: GT-Power model is the engine and Simulink harness will act as interface to Electronic Control Module (ECM) Quantify effect on engine performance using levers like Start of Injection, Rail Pressure, Fueling quantity, EGR Valve position, Turbocharger Rack Position. Need a predictive combustion model to capture effect of Start of Injection, EGR % and Rail Pressure GT Model should run close to real time Transient inputs [ 1200 sec cycle ] in which controls engineer is interested 13

14 Engine Model Capability : DI-Jet GT- Power model DI-Pulse GT- Power model Fast Running GT-Power model Reduced GT- Power model Predictive Combustion Model Old New New No Air Handling Detailed Detailed Simplified Simplified Pressure pulsations Yes Yes Yes No Crank angle resolved data output Yes Yes Yes No Simulation Time [ wrt real time ] Very slow Moderate Close to real time New DI-Pulse combustion model from GT Very fast 14

15 Transient Cycle simulation work flow : Model Calibrated with process developed GT-Power model for Calibration GT-Power model Transient Simulation Baseline Transient Simulation results Improves model simulation speed Fast Running Model conversion Fast Running Model Transient simulation Check for Fast Running Model results Fast Running Model with Simulink Harness Fast Running model for controls Detailed GT-Power Model Fast Running Model with Simulink Harness GT Conference 2014

16 Fast Running Model transient simulation results : FRM S-Function in Matlab / Simulink environment FRM Transient simulation results in Simulink environment Improvement in transient simulation time using FRM 16

17 Summary : Reduced calibration time for large simulation points. Confidence in GT-Power prediction across the entire torque speed map. FRM developed following the calibration process which gives good predictions for transient simulation FRM with predictive combustion [ DI-Pulse ] model runs close to real time simulation 17

18 Thank You 18