Control System for Internal Combustion
Engines
INVENTORS • John Moskwa, John Lahti
WARF: P05046US
View U.S. Patent No. 7,275,426 in PDF format.
Since its founding in 1925 as the patenting and
licensing organization for the University of Wisconsin-
The Wisconsin Alumni Research Foundation (WARF) is seeking commercial
partners interested in developing an engine control system that provides
precise performance control through real-time modeling and evaluation.
Madison, WARF has been working with business and
industry to transform university research into products
that benefit society. WARF intellectual property
managers and licensing staff members are leaders in
the field of university-based technology transfer. They
OVERVIEW
are familiar with the intricacies of patenting, have
worked with researchers in relevant disciplines,
understand industries and markets, and have
Older internal combustion engines have valves that open and close at the same time
during the engine cycle and were designed to be optimal over a specified speed range. Outside of this range, fuel efficiency, emissions and power become unbalanced and
suboptimal. Valve actuation systems that modify the valve position over the course of the
engine cycle have been designed to attain better performance over a greater range of
speeds. However, greater freedom in valve actuation depends on knowledge of the
correct mass air per cylinder (MAC) in order to provide the correct amounts of air and fuel
to the combustion chamber. Current methods to calculate MAC are difficult, timeconsuming and based on incorrect assumptions. A superior engine control system is
needed to improve fuel economy, emissions and performance by providing real-time and
accurate estimates of key engine parameters such as MAC.
negotiated innovative licensing strategies to meet the
individual needs of business clients.
THE INVENTION
UW-Madison researchers have developed an engine control system that models and
evaluates engine states in real-time, providing more precise control over performance,
especially in engines with variable valve actuation. Key to the technology is a
computationally efficient thermodynamic model of a cylinder, or “virtual cylinder,” which is
implemented as part of the engine’s computer system. This model estimates the mass air
per cylinder (MAC) for each actual cylinder at least a fraction of an engine cycle ahead of
real-time operation (generally, 0.1 to 4 cycles ahead). This, in turn, allows real-time
adjustments to fuel injection and other parameters, like spark advance, offering more
precise engine control. Because the virtual cylinder model estimates MAC at the cylinder
itself, these estimates may be more accurate than those achieved with traditional
techniques that predict MAC at the throttle. The model also accounts directly for cylinder
gas dynamics, rather than indirectly through volumetric efficiency (VE) corrections and
other similar techniques. Moreover, because it models cylinders individually, the virtual
cylinder approach allows the each cylinder’s fuel injection and spark to be set in
accordance with its own MAC estimate, rather than an average MAC value for all cylinders.
Wisconsin Alumni Research Foundation | 614 Walnut Street, 13th Floor | Madison, WI 53726 | [email protected] | www.warf.org
WARF: P05046US
APPLICATIONS
• Thermodynamic and gas dynamic modeling of internal combustion engines
• Precise control of engines with variable valve actuation
KEY BENEFITS
• Promises improved fuel economy, lower emissions and better performance by providing real-time and potentially more accurate estimates
of key engine parameters
• Requires fewer calibration tables than competing approaches, which reduces engine development time and possibly engine cost
• Models MAC for each cylinder individually, allowing each cylinder’s fuel injection and spark to be set in accordance with its own MAC
estimate
• Because it accounts directly for cylinder gas dynamics, the model minimizes errors in MAC estimates that often occur under transient
engine conditions.
• Measured engine parameters can be fed back to the virtual cylinder, enabling it to more accurately model actual engine states.
• In addition to intake parameters, model can calculate and control residual exhaust gas and, therefore, NOX emissions.
ADDITIONAL INFORMATION
Tech Fields
Clean Technology - Transportation
Information Technology - Software
Engines & Power Electronics - Testing & monitoring
CONTACT INFORMATION
For current licensing status, please contact Emily Bauer at [email protected] or (608) 262-8638.
Wisconsin Alumni Research Foundation | 614 Walnut Street, 13th Floor | Madison, WI 53726 | [email protected] | www.warf.org