Koskinen points out that total efficiency of hydraulic driven machines is still very low — under 5% for some mobile hydraulic systems. He feels new control systems, materials, and design methods will boost efficiency, but a lot of R&D is still necessary.
Book thinks new valving concepts will overcome traditional constraints to efficiency and performance. "Some valve designs such as the use of poppet-type valves instead of spool valves, or inherently unstable valves for fast, direct actuation will be made practical by virtue of integrated sensors and controllers," he says.
Labus notes advanced lubrication design is another area of potential improvement. "The loss of volumetric efficiency at low displacements limits the use of hydraulic components over wide displacement ranges. Advanced contact materials could significantly reduce lubrication leakage losses and increase the overall efficiency across a wider displacement range."
Prof. Monika Ivantysynova of Purdue University sees displacement control replacing resistance control as a major trend in efficiency. "Variable pumps and motors must be used as the final control element of fluid power actuators and drives," she says.
Ivantysynova contends this will help make fluid power systems more efficient. Less energy dissipation means less heat generation. The replacement of control valves leads to simpler systems by reducing the number of interfaces and fittings. "Displacement control actuators are much easier to control than valve-controlled actuators, where two different control elements — the control valve of the actuator and the pump supplying the actuator — must be simultaneously managed."
Use of the flow control valve has to stop, says Burton. "New approaches to flow modulation must be attempted if we want to be competitive. Hydrostatic systems can meet this need, but more must be done to make them practical for smaller loading type conditions."
Trinkel sees variable-frequencydrive electric motors driving fixed volume pumps as a great step forward in energy use. This combination gives infinitely variable speed at any pressure with minimum energy waste and system shock. Leaks will be less, heat will be less, components will last longer and circuits will be less complicated.
Educating the engineer of the future
It is always dangerous to predict the future of anything. In 1977, Ken Olsen, the founder of Digital Equipment Corp., felt there was no reason for anyone to have a computer in their home. Even Bill Gates was heard to say in 1981 that "640 k ought to be enough for anybody." These men were experts and innovators in the field, and they still got it wrong. However, despite such uncertainty, it is essential that engineering education become more future oriented and less of an accumulation of reactions to the past.
When I was a student, you could always tell the engineers by the way they looked: crew cut, pocket protector, and a slide rule hanging from the belt. In those days, engineering graduates sought out a job at a great American company and worked there for their entire career.
Today, the lines between disciplines are becoming increasingly interwoven, and the time-honored understanding of engineering as a whole is becoming less distinct. To many, it's no longer clear where science stops and engineering starts, or even where engineering stops and business begins. It's enough to make one wonder whether the traditional engineer as a species will still exist fifty years from now, or whether engineering will become indistinguishable among the many overlapping disciplines and interdisciplinary combinations.
What is clear is that we cannot compete in this economic climate by offering the same old solutions. The advantages of our global competitors lie at the end of the spectrum where processes and products have been standardized and become routine. Our opportunity is at the other end of the spectrum with creative, innovative, high-end products and services that offer higher value. To lead the way at the high end of the economic spectrum, we need to build an economy based on innovation.
India and China are emerging as economic powers in part because they are steadfastly investing in building world-class education systems that produce skilled technology workers such as engineers. BusinessWeek recently reported that India's schools are pumping out 260,000 engineers a year who will work for salaries much lower than in this country. China is graduating more engineers than any other country in the world — more than twice as many as the U.S. — and Russia has a large number of highquality engineers who are welcoming U.S. companies to open shop there.
In stark contrast, the number of American students earning engineering degrees began to decline in the early 1980s. For a while, we were able to offset that decline at the graduate level by attracting outstanding foreign students to fill our classrooms, and many of them stayed to take jobs in our workforce. However, those international students who still come are much more likely to return home because good jobs now await them in their own countries.
U.S. engineering education stands to be marginalized if we are passive. The education we provide to engineers must prepare them to move beyond merely fulfilling a technological function and become leaders in making wise decisions about technology and setting policies that will foster innovation.
Engineers have always been "doers," but the presence of technology in every aspect of life now calls for us to become "deciders," as well. The skills and perceptions of engineers make us well suited to play a broader leadership role in today's technological world, and the expectations of the world for engineers are higher than in the past.
We can no longer invent technology in a vacuum and put in on the shelf without concerning ourselves with the broader problems it might solve or create. The question is not merely how we can improve a piece of technology, but rather how we can change it to better serve society as a whole.
In an effort to imagine engineering's future role as a profession and suggest how engineering education can help prepare its graduates for that role, the National Academy of Engineering's Committee on Engineering Education launched the Engineer of 2020 initiative. In the traditional paradigm, change came to the engineering curriculum as an after-the-fact response to a development in industry or event in society. For example, engineering education responded to the successful launch of Sputnik by the Soviet Union by adding more science-based material to the curriculum. The Engineer of 2020 initiative wants to turn that process on its head by thinking creatively about the challenges of the future and examining bold and innovative ideas in engineering education.
Engineering educators have not been sitting on their hands. Dartmouth University and Smith College are pioneering a curriculum with a humanities focus. The military academies offer a model that incorporates strong leadership training. Institutions like Drexel, Northeastern, Kettering, and Georgia Tech incorporate a strong cooperative education component.
One way to address the challenges facing engineering educators is to develop multiple tracks, so that students choose a direction that fits their goals and abilities. The standard curriculum might be maintained as a straight technological track, while alternate tracks are developed to offer a stronger focus in other areas.
Another idea is to follow the trail already blazed before us by professions like architecture, business, and law of making the master's degree the first professional degree. This plan would provide more time for the educational process, making room to add important new elements and skills.
We also need to engage the help of the federal government. The past ten years have witnessed the decline of federal support for engineering research and the disappearance of scholarship and fellowship programs designed to encourage U.S. students to undertake advanced study. This is a critical problem, because we cannot generate the innovation on which our economy increasingly relies without new technology from research and without the help of an educated corps of students who have had advanced engineering studies.
Rather than allowing engineering to disappear in a sea of interdisciplinary fields, we can craft exciting education programs that enable it to move to the fore and offer the technological leadership and expertise the world needs to prosper.
Submitted by Wayne Clough, president, Georgia Institute of Technology, Atlanta.