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Title: A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range

Abstract

We have designed and tested a new digital signal processor (DSP)-based closed-loop feedback controller for a linear actuator system with sub-angstrom resolution and 15-mm travel range. The linear actuator system consists of a laser Doppler encoder with multiple-reflection optics [1], a high-stiffness weak-link mechanism with high driving sensitivity and stability [2], and a Texas Instruments TMS320C40 DSP-based controller for high-performance closed-loop feedback control. In this paper, we discuss the DSP-based controller design, as well as recent test results yielding step sizes below 50 picometers obtained with the atomic force microprobe setup.

Authors:
; ; ;  [1];
  1. (APS)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
925272
Report Number(s):
ANL/XFD/CP-116780
TRN: US200807%%92
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Conference
Resource Relation:
Conference: International Society for Optical Engineering; Jul 31 - Aug 4, 2005; San Diego, CA
Country of Publication:
United States
Language:
ENGLISH
Subject:
42 ENGINEERING; ACTUATORS; DESIGN; FEEDBACK; SENSITIVITY; PERFORMANCE TESTING; SIGNAL CONDITIONERS; CONTROL EQUIPMENT

Citation Formats

Smolyanitskiy, A., Shu, D., Wong, T., Experimental Facilities Division, and IIT. A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range. United States: N. p., 2005. Web.
Smolyanitskiy, A., Shu, D., Wong, T., Experimental Facilities Division, & IIT. A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range. United States.
Smolyanitskiy, A., Shu, D., Wong, T., Experimental Facilities Division, and IIT. Sat . "A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range". United States. doi:.
@article{osti_925272,
title = {A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range},
author = {Smolyanitskiy, A. and Shu, D. and Wong, T. and Experimental Facilities Division and IIT},
abstractNote = {We have designed and tested a new digital signal processor (DSP)-based closed-loop feedback controller for a linear actuator system with sub-angstrom resolution and 15-mm travel range. The linear actuator system consists of a laser Doppler encoder with multiple-reflection optics [1], a high-stiffness weak-link mechanism with high driving sensitivity and stability [2], and a Texas Instruments TMS320C40 DSP-based controller for high-performance closed-loop feedback control. In this paper, we discuss the DSP-based controller design, as well as recent test results yielding step sizes below 50 picometers obtained with the atomic force microprobe setup.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2005},
month = {Sat Jan 01 00:00:00 EST 2005}
}

Conference:
Other availability
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  • We have designed and tested a novel linear actuator system with 1-angstrom closed-loop control resolution and 50-mm travel range. There are two major ultraprecision motion control techniques that have been applied to this actuator: A novel laser Doppler encoder system with multiple-reflection optics; and A specially designed high-stiffness weak-link mechanism with stacked thin metal sheets having sub-angstrom driving sensitivity with excellent stability. In this paper, we present the system design and test results of this linear actuator. Applications of this new actuator system are also discussed.
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  • A novel laser Doppler linear encoder system (LDLE) has been developed at the Advanced Photon Source, Argonne National Laboratory. A self-aligning 3-D multiple-reflection optical design was used for the laser Doppler displacement meter (LDDM) to extend the encoder system resolution. The encoder is compact [about 70 mm(H) x 100 mm(W) x 250 mm(L)] and it has sub-Angstrom resolution, 100 mm/sec measuring speed, and 300 mm measuring range. Because the new device affords higher resolution, as compared with commercial laser interferometer systems, and yet cost less, it will have good potential for use in scientific and industrial applications.
  • The CEBAF accelerator at Jefferson Lab is currently using an analog beam current monitoring (BCM) system for its machine protection system (MPS), which has a loss accuracy of 2 micro-amps. Recent burn-through simulations predict catastrophic beam line component failures below 1 micro-amp of loss, resulting in a blind spot for the MPS. Revised MPS requirements target an ultimate beam loss accuracy of 250 nA. A new beam current monitoring system has been developed which utilizes modern digital receiver technology and digital signal processing concepts. The receiver employs a direct-digital down converter integrated circuit, mated with a Jefferson Lab digital signalmore » processor VME card. Adaptive filtering is used to take advantage of current-dependent burn-through rates. Benefits of such a system include elimination of DC offsets, generic algorithm development, extensive filter options, and interfaces to UNIX-based control systems.« less