The Center for Compact and Efficient Fluid Power is a network of academic researchers and industry experts advancing hydraulic and pneumatic technology and developing fluid-power systems that are more compact and better-performing than anything currently available. The Center’s director, Professor Kim A. Stelson of the Univ. of Minnesota, recently outlined research activities at the organization, and what lies ahead.
“The CCEFP vision is to make fluid power the technology of choice for power generation, transmission, storage and motion control,” said Stelson. We do this to improve existing applications, but also to create new opportunities in areas such as mobile equipment, robotics, and medical devices, he explained. “We do it in close partnership with industry, and one of the most important things we do is educate the next generation of leaders for this industry.”
The Center currently funds 10 research projects at about a dozen universities through the Pascal Society. (The Pascal Society is part of the NFPA Education and Technology Foundation, and it has more than 70 industry members.) Goals of this work include substantially raising fluid-power efficiency and power-storage density, developing miniature components, improving safety and sustainability, and raising manufacturing quality while reducing costs. The projects will continue through the end of 2017.
Stelson’s comments mainly focused on future research activities in three areas: off-highway vehicles, human-scale systems and fluid-power manufacturing.
The off-highway strategy focuses on funding much-needed fluid-power research via the Dept. of Energy’s commercial off-highway vehicle efficiency program. “The first step was to convince DOE that off-highway vehicles have substantial unrealized energy saving potential,” said Stelson. “We had to explain that off-road vehicles use the internal combustion engine as the prime mover and fluid power is often the power transfer method,” he explained. Unlike on-road vehicles with one input (the engine) and one output (the wheels), off-road vehicles have one input but multiple output systems (the drivetrain and work functions). Their duty cycles are also diversified and different from on-road vehicles, said Stelson.
Better integration of power systems for off-road vehicles represents a significant opportunity for raising energy efficiency. Stelson noted that a 30% efficiency improvement in off-road vehicles would save 0.6% of the nation’s energy consumption, or 600 tBTU. Potential technologies to achieve such energy savings include:
- Efficient fluid power actuation enabled by modular power supplies, new architectures such as hybrid, and more-efficient components
- Tighter integration of fluid power systems with combustion engines
- Connected and automated off-road vehicles to improve efficiency and productivity
“Connected vehicles are a hot area for research right now, primarily addressing on-road applications. But off-road applications are actually easier and more-attractive in the short term,” said Stelson. For instance, a construction site can be fenced off and controlled by one entity, letting automated equipment safely work together without human intervention. “That differs from a public road where you’re dealing with pedestrians, dogs running across the road, bicycles, all manner of confusing things for automated systems. This industry could lead in connected vehicles,” he stressed.
Given buy-in by DOE, the Center then lobbied Congress for needed funding. “This is getting research dollars the hard way. But we had no other options as this research area is really underfunded in the Federal government,” he explained. The good news: Congress recently approved an additional $5 million appropriation for the Vehicle Technologies Office, which will seek competitive proposals to improve the energy efficiency of fluid power systems for off-road vehicles. Stelson expects the final budget to be approved in April 2017.
A task force is creating a plan to effectively respond to the DOE program. Possible research topics with high upside potential, said Stelson, include continued work on the CCEFP displacement-controlled excavator, free-piston-engine powered vehicles, engine management and advanced drivetrains, and energy storage and waste-heat-recovery concepts demonstration.
“The program seeks projects to improve the system-level performance of fluid-power systems by at least 30% over current systems,” he continued. Any U.S. company or academic institution can submit a proposal and funding is for two years at $0.5 to $1.5 million/year. Renewal funding is possible. At least one academic and two industry partners per proposal are required. The long-term goal is $10 million in funding by the third year, which would then continue annually. “This would be a huge shot in the arm, for both academia and industry, for research in this area,” added Stelson.
Human-scale research
The second focus going forward is on human-scale fluid power research. Human-assist devices can enhance workers’ capabilities, restore mobility or provide therapy, said Stelson. Leading markets and applications include manufacturing and construction, defense, assistive/elderly, rehabilitation devices, spinal-cord injury, prosthetics and orthotics.
“If you look at all the applications, they beg out for fluid power, but almost none of them have it. They have very wimpy electric drives and they really need the power density of fluid power to improve performance,” he said.
“In contrast to the off-highway vehicle project, there is already a large research establishment attracting government funding for human-scale research, for example involving robotics and exoskeletons. What is surprising, while this is a very sophisticated research community, there is little to no awareness of fluid power’s potential as an actuation technology.” This presents a huge opportunity for future growth, he emphasized.
The Center’s first step is to partner with the existing research establishment and increase industry awareness of fluid power opportunities. To help gain a foothold for human scale fluid power engineering, the CCEFP joined the Advanced Robotics Manufacturing Institute headed by Carnegie Mellon University, a research consortium which is seeking up to $70 million in support from NIST. As a result, Vanderbilt and several fluid power companies have submitted ARM proposals and funding could begin in early 2017.
Fluid power manufacturing vision
CCEFP’s third strategic focus, manufacturing, will support both the off-road and human-scale initiatives. Researchers are developing a “roadmap” of areas of interest and how they relate to current and future requirements of fluid power suppliers and users. Ten key emerging manufacturing technologies have been identified. These include coatings, micromachining, composites, additive manufacturing, batch-free heat treating, and in-process sensing, feedback and control.
The group is exploring opportunities for collaboration with experts in these areas. Funding manufacturing research is a top federal priority among agencies like DOD, DOE, NIST and NSF. CCEFP is actively working to attract funding in these areas.
“Another major initiative in the manufacturing area that is very exciting, and we expect it to raise a lot of interest, is the AME project,” said Stelson. The Additive Manufactured Excavator (AME) is being built using nontraditional methods, and it will be showcased at Conexpo/IFPE this March in Las Vegas.
A carbon-fiber reinforced composite cab has already been printed by students from the Univ. of Illinois Urbana-Champaign at the Big Area Additive Manufacturing area at the Oak Ridge National Laboratory. Other excavator components being fabricated include the steel boom printed by an additive-manufacturing welding process; and an aluminum-powder-bed 3D printed oil-cooler heat exchanger. The AME will actually operate in the futuristic Tech Experience pavilion at Conexpo.
