Enginuity:
Frequently Asked Questions

What is Enginuity?

Enginuity is a Matlab/Simulink-based real-time engine model tool package that supports virtual control system development, system validation and HIL testing of production intent engine controllers. The tool package involves a Simulink-based component model library and a set of graphic user interfaces tools that facilitate a swift, automated model calibration process. Enginuity supports port fuel and direct injected spark ignition engine applications, direct injected compression ignition applications, and homogeneous charge compression ignition applications. Enginuity models represent a thoroughly physics-based, zero-dimensional modeling approach. The library model blocks are organized within dedicated library modules and are deployed within the Simulink modeling environment in the form of standard Simulink s-function blocks. The set of available s-function blocks entail both fully assembled engine models for various engine applications and module blocks for various physical engine components. A custom Enginuity engine model assembly can thus be built from component modules just like a real engine assembly.

When do I need Enginuity?

You may want to consider Enginuity if you are using Matlab/Simulink as your primary control system design platform and you are contemplating a move toward an entirely virtual engine control system design approach. A critical prerequisite for such an approach is a real-time capable engine model that emulates the relevant static and dynamic engine characteristics with sufficient accuracy across the entire engine operating-envelope. Performance-wise, a fully calibrated Enginuity model fits this description and can be viewed as a particular fleet specimen of the selected target engine application. Thus, within the virtual development paradigm, Enginuity models are used as a substitute for the real engine for all kinds of development tasks. Enginuity models fit seamlessly into the Matlab/Simulink environment and support control strategy development at any level of complexity both for exploratory purposes but also for production intent applications. Possible usages include the swift procurement of linear control models, the initial calibration of controller settings, the validation of algorithm candidates, and many more. Hence, Enginuity is a very powerful tool for embedded engine control system applications that are either subject to extremely challenging lead times or where experimental development efforts must be minimized or both.

How does Enginuity work?

First and foremost Enginuity models work like any other models that have been built from native Simulink modeling blocks. The model blocks are deployed within custom Simulink system models via the standard Simulink library browser. The library browser modules provide access to either a number of fully preassembled model blocks for various engine application types or to a number of elementary engine component modules that support the swift assembly of custom engine models for any given target engine configuration, i.e., for engines with any number of cylinders and any engine bank and exhaust system configuration. Enginuity also supports arbitrary engine firing orders. In addition to the specific model configuration Enginuity models are customized with respect to a specific target engine application in terms of a predefined set of model parameters. Most of these parameters represent the geometric characteristics of the target engine and material properties. A small portion of the parameters represents regression parameters. These parameters allow for adjusting the torque and gas flow characteristics of the model. This adjustment typically involves a representative set of experimental engine performance data (standard engine mapping data) which is used to formulate a performance error metric. Each step of the entire model calibration process, i.e., the provision and the management of specific model parameters for the engine geometry and for the material properties, the provision and handling of specific engine performance data, and the actual adjustment of the regression parameters as a function of the performance error metric is fully tool supported and largely automated. The customization of an entire model, i.e., the model assembly from library blocks and the model calibration based on experimental data can thus be accomplished within a matter of hours.

What are the benefits of using Enginuity?

Enginuity models calculate the engine dynamics on a crank angle basis for each cylinder so that the models inherit the cyclic nature of the real engine. A properly tuned Enginuity model provides high simulation accuracy across the entire engine operating-envelope. Due to the components-based modeling approach (models are built from components just like a real engine) Enginuity affords a high level of model reusability while preserving the flexibility to customize models for particular target applications. Furthermore, due to its real-time capabilities Enginuity not only affords HIL testing but also rapid interactive control system development and testing within the Matlab/Simulink environment.

Which engine component models are included in the Enginuity model library?

In a nutshell, Enginuity provides models for all engine components which are relevant from a control system development view point. These are all those engine components which affect important engine performance signals such as engine torque, engine speed, and engine mass flow.

What specific model features are entailed in Enginuity?

Dynamic Enginuity model equations are implemented in discrete time notation on the basis of a simple Euler integration method with a fixed sampling rate (integration step size) of 250 μs. This sampling rate corresponds to a crank angle resolution of 0.9 degs at 600 rpm and 9 degs at 6000 rpm. Specific features of Enginuity include cycle-by-cycle engine emulation, emulation of the engine firing order, variable compression ratio, the tracking of 12 individual gas species throughout the engine, the emulation of the port fuel dynamics (for PFI engine applications), the emulation of premixed and diffusion controlled combustion portions (for direct injection engine applications), simple kinetic reaction models (Extended Zeldovich mechanism plus radical formation) and many more.