The EPPC™ compared to mechanical-pneumatic level control systems
The wide range of adjustable damping
leads to a significant increase in
performance compared to currently
used mechanical pneumatic levelling
systems (e.g. Bilz MPN):
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Decreasing resonance
amplification factor (matching
ratio = 1, see chart on the right)
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Short settling time (see chart
below)
The efficiency of any vibration isolation system depends on the damping properties of the
isolator and the matching ratio η between excitation frequency and natural frequency:
The settling time, which is required to reach and stay within a certain range, is reduced. For an excitation amplitude
of -80 µm, the response curve of the respective isolation system is shown. To reach a stable position within a range
of e.g. 15 µm, the settling time reduces by 45 % from approximately 0.75 s to 0.4 s.
Real-time level control system for efficient vibration isolation
Bilz Vibration Technology AG
Böblinger Str. 25 D-71229 Leonberg Germany
phone: +49 (0) 7152-3091-0 fax: +49 (0) 7152-3091-10
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[email protected] www.bilz.ag
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Control and supervision of the level control

Easy set-up and utilization
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Interface between browser based configuration/
diagnostic tool (WebVisu) and the control valves
via ethernet (no software installation required)
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Remote control maintenance interface
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State indicator for the operator (Error, Ready,
Working Position, MC/ Motion Complete)
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Provides digital I/O ports for external control and
supervision systems
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CAN-Bus topology
allows a simple electronic wiring
and a distance of up to 20 m from the PLC
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Internal database for multiple system setups
BiAir® membrane air spring isolator
Electro Pneumatic Position Control
The EPPC™ is a real-time level control system which provides efficient vibration isolation for highly dynamic and
vibration-sensitive machines. Therefore, the EPPC™ can be installed with a wide range of high-precision machines,
where the focus is on optimal level accuracy of +/- 8 µm over a 12 mm range and little deflection as well as short
settling times at load changes.
Field of application:
System characteristics
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High-precision machines
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Vibration-sensitive machines
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Highly dynamic measurement, testing
and production machines
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Microscopes and machinery for the
semiconductor industry
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Real-time level control for air spring systems with up to
six degrees of freedom
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Optimal level accuracy of +/- 8µm
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Adjustable system parameters (e.g. damping)
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Little deflection and short settling times at load changes
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One high-performance servo valve and one position
sensor per degree of freedom
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Intelligent browser based user interface (WebVisu) for configuration, diagnostics and monitoring
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Reliable and robust air-spring technology
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Compatible with Bilz standard BiAir membrane air-springs
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Noise free regulation by using high resolving signal processing and optimized pneumatic design
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No disturbing heat generation, magnetic variations or high electrical power consumption as observed at
electromagnetic actuators and linear motors
The EPPC™ can be combined with three or six groups of air springs to
control up to 6 degrees of freedom. It monitors the machine position
for every degree of freedom as well as internal air pressure of the air
springs to control the dynamic behavior of the system. Multiple air
spring types and sizes are available to ensure that design and layout
of the isolation system perfectly match the individual demands of the
specific application.
The two chamber system design consists of a load and a damping
volume. Both volumes are connected by an adjustable mechanical
bypass throttle valve. Any deflection of the isolated machine on top of the element leads to a change of the size of
the load volume and a resulting
airflow from one air volume to
the other through the bypass.
Due to air friction inside the
bypass, energy will be converted
into heat and damping up to a
maximum value of D = 15% can
be created with the air spring
itself. In combination with the
electronic control, the damping
can reach up to 30 %.