precision high-speed proportional pneumatic systemscfnewsads.thomasnet.com/pnn-pdf/450228.pdfthe ls...

LS System

precision high-speed proportional pneumatic systems

solutions for theSmart Designer

LS System Overview

Enfield Technologies vs. Solenoid Technology

How Fast Is Fast?

PositionPressureForceFlowVelocity

Control

ProportionalHigh SpeedLinear Real Time

The LS System is a high speed, proportional pneumatic motion control system comprised of a specialized, patented servo-valve and a dedicated valve controller. The LS system can be used in open loop and closed loop configurations. Linear pro-portionality at both the electrical and mechanical levels improves control and provides the motion fluidity that is preferredfor automation, testing, and animation. The system allows unprecedented valve aperture control. Designers can use 1 valvewhere 2 or more are often needed, decreasing complexity and lowering both purchase and maintenance costs – a simpleand cost effective solution.

toll free North America 800 504 3334 www.enfieldtech.com

typical solenoid valve

high performance solenoid valve 19.5ms

35.5ms

Enfield Technologies valves5ms 4 to 7x faster

0 5 10 15 20 ms

100%

80%

60%

40%

20%

fully open

fully closed

Create breakthrough applications and enhance existing applications

Overcome speed and control barriers Decrease machine cycle time and

increase throughput Increase machine and process flexibility Allow rapid changeover capability Utilize advanced control with real-time feedback

Performance


What is Proportional Control? Proportional control means that the output of a system is directly related to theinput. System inputs include both a target value, which is the desired result such as a specific position, pressure, or forcelevel, and the real-time measurement of actual progress toward that goal. With proportional control, the output of a systemcan be any interim value within a fixed range. For example, an air cylinder can be positioned anywhere between fullyretracted and fully extended. In another example, a tank’s pressure can be maintained anywhere between vacuum andfull line pressure. Proportional control is a cost effective way to create systems with high flexibility and dynamic control.

Enfield at Work Controlling the Crunch

A branded snack food company prides itself on the product consistency its customershave come to expect. To process one of its flagship products, a frying operation seeksto accurately position the product within optimal temperature pockets in a frying bath.The temperature pockets are measurable, but unpredictable because of complex fluiddynamics, requiring the motion control system to have infinite variability. Using anarray of heat sensors and an Enfield Technologies motion control system, the fryingmachine is able to continuously move the product quickly to the optimal position.

Enfield Technologies Valve Controller

Process Controller

Enfield Technologies

ValveDevice with

Sensor

auxiliary feedback

status feedback

goal feedback

motor feedback

goal command valve current control air control

Multiple Feedback System Design

Motor Feedback Active closed loop valve current feedback monitors and manages valve’s linear force motor

Goal Feedback Active closed loop goal feedback monitors and manages the primary command instruction

Auxiliary Feedback An optional secondary feedback allows for modification of the primary command signal; mayalso be used as an alternate command signal path

Status Feedback Two state process status indicator; actual primary goal feedback level monitoring also possible

LS-C10 Pneumatic Device Controller

LS-C11 Sensor Signal Conditioner

Accepts two external sensor inputs Onboard facility for a dual acting sensor Can process low voltage level output sensors such as pressure, force, or accelerometers Offset and Span adjustments (non-interacting) for each sensor input Individual outputs for each sensor Differential output of both sensors

Low cost, high performance dedicated device controller Proportional gain adjustments 2 Khz square wave adjustable dither voltage source to eliminate sticktion friction Goal achieved signal (eg, at position) with adjustable threshold window comparator Capable of delivering high power/current output up to 2 Amperes with closed loop control Auxiliary input allows process controller (PLC, etc.) to use LS-C10 as a signal amplifier, conditioner,

and manager 4-20 mA to 0-10 Vdc buffered voltage converter

LS System Electronics

Electronics Specifications LS-C10 LS-C11

Power Requirements min ± 12 Vdc @ 25W or 1.0 A ± 12 Vdc @ 2.5W or 100mA

Command Signal Input 0-10 Vdc or 4-20 mA ± 500 mV maxor ± 10 Vdc

Feedback Level 0-10 Vdc, 4-20 mA, ±10 Vdc -

Auxiliary Feedback Level ± 10 Vdc -

Voltage Output - ±10 Vdc @ 2mAfor ±100 psig

Position Output 0-10 Vdc (±10 Vdc) -

Response Time <100 µSec <100 µSec(10-90%, 10-90 psig)

Operating Temp. Range -25 C to +85 C -25 C to +85 C(-13 F to + 185 F) (-13 F to + 185 F)

Optional Components - Onboard Pressure Transducer

Dimensions 7.5 x 8.0 x 3.5 cm (3.0” x 3.1” x 1.4”) 8.5 x 7.5 x 2.5 cm (3.3” x 3.0” x 1.0”)

Weight 125 g (4.4 oz.) 94 g (3.3 oz.)

Mounting Direct mount plate using 4-40 screw


Faster.Smarter.

Smoother.

integratedcircuit

Multi-signal processing with convergent and additional control

LS System ValveLS-C10 Pneumatic Device Controller

LS System Specialized Circuitry

Linear motor drive control with active current feedback

integratedcircuit

signal adjuster

signal adjuster

integratedcircuit

powerstage

currentsensor

linear force motor

feedback signal

primary commandsignal

alternate command signal or auxiliary feedback signal

active currentfeedback

Convergent controller circuitry

• Real-time command and feedback signal monitoring• Signal disparity drives valve to converge on goal• Analog processing yields a highly responsive

overall system• Multi-signal processing capability

Active valve current feedback control

• Continuous real-time monitoring and management of linear force motor

• Instantaneously corrects for external disturbances

Differential Pressure and Additional Feedback Path

• Provides additional feedback when the system requires more stability for varying load conditions

• Covers a wide range of transducer sensitivities

Enfield at Work Making Music

A musical instrument company makes acoustic guitars using ahand layed-up laminating process. Enfield Technologies helpsimprove and speed the process by automating the form jigs withan advanced motion control system. Proportional control accu-rately positions the jigs for use in differing guitar designs. Theautomation of this activity results in a consistent and optimizedproduction process, providing the guitar maker with flexible manu-facturing and rapid changeover benefits.

Closed Loop vs. Open Loop If you

want to control it you must measure it. Closed

loop systems are actively managed using feed-

back from sensors that monitor actual per-

formance. This feedback is continuously com-

pared to the desired value and corrective

action is taken until the goal is achieved.

While open loop systems are simpler, actual

performance is left to chance. Closed loop

systems are needed when precision is required,

when the system may be subjected to external

disturbances, or when the desired value might

change during a process.


Technology Highlights

Linear Force Motor vs. Solenoid Although solenoids have been the workhorse of

pneumatic valves, they are slow, non-linear, and hard to control. And, you need 2 of them for

directional control. In its patented design, Enfield Technologies uses a specialized directly

coupled linear force motor. This motor uses a voice -coil type winding and an intensified rare

earth magnetic field. With low inertia and bi-directional control, a single valve operates

in true linear fashion 4 to 7 times faster than a double solenoid valve, allowing

more cycles in the same amount of time with fewer components.

LS-V25


LS-V05LS-V15

LS System Valves

Unique, patented valve design Linear force motor with rare earth neodymium magnet Faster and more accurate than solenoid valves Proportional, bi-directional control Directional control: 3 extreme positions with infinitely

variable intermediate positions with controlled aperture Normally closed, blocked center position when off Can be used as an ultra-fast on/off valve 3 sizes with different effective apertures cover

a wide range of volume and mass flow capacities Rust resistant nickel-plated motor element Smooth, low noise, jitter free operation

Directly coupled lapped spool and sleeve

• Reliable operation for service life of millions of cycles

• Spool and sleeve precision matchedto 3 microns (3 millionths of an inch)

• Air bearing eliminates troublesomeseals and reduces friction

Bi-directional linear force motor

• Single element moves valve spool in both directions

• High bandwidth (100Hz) is resistant to vibration

• Linearly proportional spool movementvirtually eliminates hysteresis

Technology Highlights

Faster.Smarter.

Smoother.

LS System Valves


approximate matching of valves to cylinders(no load, closed loop control)

0 1 2 3 4 5 in0 2.5 5.1 7.6 10.2 12.7 cm

cylinder bore

cm/s in/s

76.2 30

50.8 20

25.4 10

ISO Symbol

LS-V05 LS-V15 LS-V25

Valve Specifications LS-V05 LS-V15 LS-V25

Max. Aperture (mm2) 5mm2 15mm2 25mm2

Max. Valve Coefficient (Cv) 0.13 0.35 1.0

Flow Capacity (@ 80 psig line pressure) 128 NI/m 345 NI/m 985 NI/m(6 SCFM) (16.21 SCFM) (46 SCFM)

Wattage 3.4 Watts 3.2 Watts 2.6 Watts

Maximum Effective Command Current 0.97 A 0.94 A 0.85 A(current required to open fully in either direction)

Ports 10-32 UNF-3B 1/8" NPTF 1/4" NPTF

Dimensions (length, width, height) 6.5 x 2.5 x 3.1 cm 8.3 x 3.5 x 4.7 cm 12.8 x 5.0 x 7.7 cm(2.6" x 1" x 1.2") (3.3" x 1.4" x 1.9") (5.0" x 2.0" x 3.0")

Weight 107 g (3.8 oz.) 340 g (12 oz.) 669 g (23.6 oz.)

Inductance 1.7 mh Air Pressure Range vacuum to 10 bar (28" Hg vacuum to 150 psig)

DC Resistance 3.6 Ω Temperature Range -23°C to +46°C ambient (-10°F to +115°F)

Time Constant 0.47ms Electrical Connection 3 pin pico M8 female end cable to male screw-on valve terminal,

Response Time 2.5 ms 24 AWG cable

Bandwidth 100Hz Media dry non-lubricated air, vacuum, non-flammable & non-corrosive dry gases

(0.3 micron fine grade coalescing filter with 5 micron pre-filter preferred)

Nominal Speed Curves

Enfield at Work Zoom

An international marine engine manufacturer needs to

accelerate the casting process of its aluminum engine

components. Using Enfield Technologies servo-pneumatic

control systems, the pressure profile of casting vessels is

dynamically modified to accommodate the production of

different parts on the same line. Using the same equipment

for different parts eliminated changeovers, lowers capital

equipment expenditures, and increases productivity.

Enfield Technologies, LLC

41 Monroe TurnpikeTrumbull, CT 06611 USA

tel +1 203 459 0700fax +1 203 459 2762

toll free North America1 800 504 3334

www.enfieldtech.com

Enfield Technologies pledges continuous innovation anddedication to customer service.

High in-stock availability and same-day shipping

Prompt response to sales and technical inquiries

Advanced engineering services

Standard 1 year warranty and extended warranties available

Volume and OEM program pricing

Market-driven product development

Online account management (status, history, orders,

shipment tracking, customer service case management)

Online resources include 2D and 3D CAD drawings, tech

notes, application notes and educational materials.

Direct online purchasing and charge card acceptance

© 2003 Enfield Technologies, LLC. All rights reserved. Enfield Technologies’ name and logo are trademarked.

These products are protected by one or more of the following US patents: 5,960,831 and 5,460,201.

Caution: Installation and operation of electronic and compressed air systems involves risk. Users should

be appropriately trained and take appropriate safety precautions. ver. 200401

Innovation and Service

Manufacturing ofServo-Pneumatic

Systems

ApplicationDevelopment and Support

Custom ProductDevelopment

Repair and Testing

Services

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