IBM's modeling software, Telelogic Rhapsody, has been a key tool for Eaton in its development of hydraulic-hybrid vehicle power trains, which will see commercial use starting in the first half of 2009..
The series hydraulic hybrid (SHH) system replaces the conventional drive train and transmission for a small fleet of UPS delivery vans. The system uses hydraulic pumps and accumulators to regeneratively capture and store energy, rather than use electric motors and batteries.
UPS will deploy the first two SHH powered vehicles in Minneapolis. Eaton will monitor the vehicles fuel economy performance and emissions. An additional five vehicles will be deployed later in 2009 and early 2010.
As with automotive electronics, where around 85% of functionality is software controlled, hybrid hydraulics is an intelligent, software-intensive system. Telelogic Rhapsody saves time in the development of these hybrid systems by modeling the control software, thus shortening the design cycle.
With "smart" hybrid hydraulics, fuel economy is increased by regenerative braking that recovers energy usually lost in friction braking. The primary diesel engine can also operate at its efficiency "sweet spot" and be shut off when stopped or decelerating. In the stop-and-go trials typical of package delivery, the SHH system showed upwards of 50% improvement in fuel economy and a one-third CO2 emissions reduction.
"Using Telelogic Rhapsody software improves the quality of the application software that is integral to the series hydraulic hybrid system development process," said Steve Zielinski, chief engineer for software in Eaton's Fluid Power Group. "IBM's Telelogic Rhapsody increases communication through graphic modeling, and provides validation through simulation and automated testing."