Exclusive interviews with technology leaders
Charting the growth of servopneumatics
Hosrt Saalbach, President Festo
Most engineers know the widely accepted reasons for
selecting pneumatic systems: Pneumatic components provide
high force and high speed at relatively low cost. Recently,
however, pneumatic systems have begun offering a new
wrinkle: Mid-stroke positioning, with accuracies that
would have once been considered impossible. Design
News asked Horst Saalbach how these developments
in pneumatics will affect the future of automation.
Design News: When engineers have a motion-control
problem, their first inclination is to think of electric
motors and drives as a solution. How do you intend to
educate them about the advantages of servopneumatics?
Saalbach: There has been a noticeable increase
in the number of enlightened engineers in the past decade
who have availed themselves of emerging technologies.
Now more than ever before, industry is in need of the
most cost effective way to produce increasingly more
complex and miniaturized parts and assemblies, and to
provide adaptive positioning equipment for applications
involving pick-and-place, dispensing, and packaging.
This has led to a more in-depth investigation into servopneumatics
as an alternative to more costly motor-control solutions.
Q: Are engineers starting to get the message--in
other words, have you seen an increase in the use of
servo-pneumatics in recent years?
A: Servopneumatics have evolved over the past
10 years, and with that evolution we have experienced
geometric increases in inquiries from both new and existing
customers. Our face-to-face experiences with potential
users have resulted in spirited exchanges of information,
and we have determined that a great deal of effort must
be concentrated on educating the market. We've discovered
that there are tiers, or levels of acceptance, that
this technology must survive. But once the equipment
proves itself, the rest is academic, because it is cheaper
and every bit as reliable as the industry-standard electric
Q: What kind of applications are you targeting right
now for servopneumatic solutions?
A: This must be answered from a generic standpoint
because intelligent motion applications are so diverse.
We have determined that, with respect to accuracy and
payload capacity, nearly 70% of the intelligent-motion
market can potentially be served by servopneumatic technology.
Like all intelligent-motion solutions, their suitability
must be evaluated on a case-by-case basis. Our experience
has revealed, however, that particular interest has
been shown by the packaging industry, as well as part-handling
and assembly. However, it must be stated that nearly
all industrial sectors could potentially benefit.
Q: Is there a subset of motion control applications
where servopneumatics is clearly not the best solution?
A: Generally, the following types of motions
are not good candidates for servopneumatics: Multi-axis
interpolation; multi-axis applications requiring vector-velocity
regulation; velocity tracking; and motions requiring
extremely slow speeds with large payloads.
Q: How much do you expect servopneumatics to grow
during the next five years?
A: As we see it, the growth of servopneumatics
is highly dependent upon a continuous education program.
Efforts are directed at understanding the obstacles
not only of the technology, but of the dynamics of penetrating
a cautious and inquisitive market. As industry continues
to realize that not every positioning application requires
a servo or stepper motor driving a lead screw under
the direction of a sophisticated numerical controller,
and all the cost that goes with it, servopneumatics
will come to rule in its own domain.
††Therefore we suspect that market acceptance
and product identification are closely linked, and as
the need arises, servo-pneumatics will grow in geometric
proportions in low- to medium-accuracy positioning and
high speed applications.
Q: In terms of performance, how much better can
A: As this technology is increasingly accepted
by industry, improvements in performance will be inevitable.
These improvements are most likely to focus on actuator
design and loop-control algorithms. More immediately,
however, will be the second generation systems that
are more user friendly in terms of implementation. Improved
software, modularity and set-up will make this product