The Southwest Research Institute(R)-developed apparatus uses hardware-in-the-loop technology and a software-controlled simulator to determine how a powertrain or related component would perform if it were integrated into a vehicle.
"Receiving the R&D 100 for the VVTTC is a great honor. This system represents a breakthrough in vehicle and component simulation, reducing the vehicle's development cycle by a year or so," says Gary Stecklein, director of the Vehicle Systems Research Department in SwRI's Engine and Vehicle Research Division.
SwRI(R) engineers designed and constructed a test system that simulates the operation of a transmission under a wide range of real-world conditions. Similar test systems can be developed to test engines, electric motors, hybrid-vehicle battery packs and other equipment under a variety of road and environmental conditions.
The equipment and test cell were developed as part of a program funded by General Motors Corporation to test transmissions in the laboratory using an electric motor to simulate an internal combustion engine. A second electric motor is used to provide road load, grade resistance and vehicle inertia simulation in the output of the transmission.
"This system can greatly decrease the development cost and the time to market for a new vehicle," explains Stecklein. "Engineers can evaluate a prototype transmission, for example, while the engine is still being developed. Using SwRI's internally developed RAPTOR(tm) VSM powertrain simulation software, we can perform numerous driving cycles to simulate real-world driving conditions and eliminate some fleet testing."
The VVTTC has a unique capability to simulate conditions such as stop-and-go traffic, roll and grade angle, heat rejection, aerodynamic drag, varying temperatures and other parameters.
A key component in the VVTTC is the input motor system, known as the engine simulator, which consists of a low-inertia, alternating current motor and a high-speed control system. This 442-horsepower electric motor can operate at speeds up to 9,000 revolutions per minute and has a tilt range of 45 degrees.
The electric motor functions as the engine of a vehicle, providing the speed and torque of a wide range of combustion engines. It also replicates the engine inertia that a transmission experiences during shifting as well as engine-generated torsional vibrations. The system can simulate numerous driving cycles required by national and international standards.
"We expect to develop and market similar test systems for engines, electric motors, batteries, and accessories for automotive and equipment manufacturers and other service providers," Stecklein continues.
In addition to the VVTTC, SwRI also won an R&D 100 award this year for NASGRO(R) 4.0 Fracture Mechanics and Fatigue Crack Growth Analysis Software. The software code calculates the crack growth rate and remaining structural life of components undergoing cyclic loading and also calculates the conditions, such as loads and crack sizes, that cause failure by fracture.
In all, SwRI has won 26 R&D 100 awards since 1971. The awards are to be presented in Chicago on Oct. 16, 2003. For further technical information about the VVTTC, call Stecklein at 210-522-2973.
EDITORS: An electronic image of the VVTTC is available to media at www.swri.org/press/vvttc.htm.
SwRI is an independent, nonprofit, applied research and development organization based in San Antonio, Texas, with more than 2,800 employees and an annual research volume of more than $339 million.