Integrating the curriculum using a bench-scale hybrid power train

The Rowan University Mechanical Engineering program is studying the use of a long-term (five semester) design project on student learning and concept retention. The project, a bench-scale hybrid electric powertrain system, is designed, analyzed and fabricated by students in five modules, starting in their sophomore year and culminating in their final semester as seniors (see prior ASEE publication [1]). This complex project has been selected in order to integrate the core mechanical engineering courses: Mechanical Design, Thermodynamics, System Dynamics and Control, and Fluid Mechanics. A bench-scale hybrid-electric vehicle powertrain has sufficient complexity to involve all Mechanical Engineering disciplines and the simplicity to be built by students over the course of five semesters. In addition, hybrid-electric technology is at the cutting-edge of automotive technology, and has been found to hold a special fascination for most mechanical engineering students. A "faculty prototype" has been built and tested, both as a demonstration and for educational purposes. This paper describes the overall project: how the modules are integrated into the system and its control algorithm. The system is a simplified model of the Toyota Hybrid System (THS) [2] but adapted to a classroom environment. The overall goal of the control strategy is to implement a "cruise control" system that keeps the output speed constant under varying loads, while maximizing fuel economy. The "fuel" for the system is compressed air, and the prime mover is a student designed-and fabricated-air powered engine. Some details of each module for the hybrid-electric powertrain prototype are provided so that it may be easily implemented by instructors at other institutions. A comprehensive website, benchtophybrid.com, is under development. This work is supported by the NSF-TUES program, grant number 1044532.