Preview for Enginuity Version 5.0

1. Overview
2. New Features
3. Model Parameters and Static Engine Mapping Data
4. Model Calibration
5. Enginuity and Beyond ...

Overview:

Enginuity is a Matlab/Simulink based engine model tool package designed to support engine control strategy development and hardware in the loop testing. The tool package includes simulink library model modules for the modeled engine component blocks and a set of user interface tools that support model calibration as well as the handling of model parameters and the management and formatting of empirical engine performance data. Enginuity largely embraces a zero-dimensional, yet thoroughly physics-based modeling approach. This modeling approach ensures real-time model execution on the one hand and maximum model performance with a minimum of model calibration effort on the other hand. A particular focus is on the development of intricate, real-time capable cylinder models that capture the true physical nature of mixture preparation and heat release. Enginuity supports traditional port fuel injection applications as well as modern direct injection applications with multiple injection pulses as well as a wide range of auxiliary features such as turbocharger, variable valve actuation (variable cam phasing and two step valve lift actuation), variable compression ratio, etc.
The tool package includes an engine component model library which offers preassembled models for standard engine configurations and individual component model blocks for custom model assemblies. Enginuity includes models for all those engine components which are relevant from a controls-oriented perspective. The following is a graphic illustration of the modeled engine components.

New Features:

Enginuity supports port fuel injection (PFI), spark ignition direct injection (SIDI), compression ignition direct injection (CIDI), and homogeneous charge compression ignition (HCCI) engine applications.  The tool package 5.0 features a completely reworked user interface to support an effortless model calibration process for all supported engine applications.  This includes support for defining, editing and managing the model parameters, support for entering and processing empirical engine performance data, and support for the actual calibration process.

Model Parameters and Static Engine Mapping Data:

The adjustment of the model performance with respect to empirical engine data follows the principles of multidimensional unconstrained nonlinear parameter optimization. The entire optimization process is based on built-in Matlab functions. Within the context of this parameter optimization process, selected parameters of the Enginuity models are adjusted until satisfactory model performance is obtained. Enginuity offers a tool set which guides each step of the model optimization process in a convenient and largely automated fashion. This includes preliminary steps in which the user specifies the geometric nature of the target engine and supplies empirical data which characterizes the target engine's static performance characteristics (engine mapping data, specific torque hooks, etc.).

Model Calibration:

The actual model optimization process involves a sequence of steps which is independent of the type of the target engine application (i.e., PFI, SIDI, CIDI or HCCI). The initial steps of the optimization process always involve a particular reference operating point. In each of these initial steps, a specific subset of the adjustable model parameters is tuned until the model matches the empirical performance of the target engine in terms of one specific performance characteristic (e.g. in terms of a spark vs. torque hook for spark ignition engines or in terms of an injection time vs. torque hook for compression ignition engines, etc.). Once the model adjustment in this specific operating point is accomplished the model optimization process transitions to the final step. This step involves the adjustment of a remaining set of model parameters with respect to empirical engine data that characterizes the entire range of engine operating conditions. Each step of the model optimization process is fully automated. The time it takes to accomplish a particular optimization step varies and depends both on the computational power available and on the number of data points included in the empirical data set for this particular step.

Enginuity and Beyond ...

Go Virtual! Combine Enginuity and UniPhi in Matlab/Simulink and experience the power of virtual engine control system design.

UniPhi is a system architecture modeling tool that is meant to support a Model-Based Software Development process and Automated Code Generation. UniPhi affords "wireless" signal transfer between all features of the architecture model, plug-and-play algorithm implementation, and a seamless transition across all stages of a production development program. In early control system development stages UniPhi can be combined with an Enginuity engine model to rapidly and interactively evaluate control system performance even down to the level of task scheduling and signal processing features. The fully integrated control system can thus be tested in an early development stage before changes become expensive.

This combination of virtual development tools has been successfully deployed to support the development of

• cam phasing calibration and control
• individual cylinder A/F-ratio control for V-engines with uneven firing events
• low-cost air estimation for PFI engines
• air charge estimation for homogeneous charge compression ignition engines
• closed loop dilution control at the dilution limit