With the development of optoelectronic information technology, high-performance optical systems require an increasingly higher surface accuracy of optical mirrors. The fast tool servo (FTS) based on the piezoelectric actuator is widely used in the compensation machining of high-precision optical mirrors. However, with the low natural frequency of mechanical structures, hysteresis of the piezoelectric actuators, and phase delay of the control systems, conventional FTS systems face problems such as a low working frequency and a large tracking error. This study presents a method for the design of a high-performance FTS system. First, a flexure hinge servo turret with a high natural frequency was designed through multi-objective optimization and finite element simulations. Subsequently, a composite control algorithm was proposed, targeting the problems of hysteresis and phase delay. The modified Prandtl-Ishlinskii inverse hysteresis model was used to overcome the hysteresis effect and a zero-phase error tracker was designed to reduce the phase error. The experimental results reveal that the tracking error of the designed FTS system was <10% in the full frequency range (0-1000 Hz).
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8620653 | PMC |
http://dx.doi.org/10.3390/mi12111354 | DOI Listing |
Am J Emerg Med
January 2025
Department of Pharmacy, Sarasota Memorial Health Care System, 1700 S Tamiami Trail, Sarasota, FL 34239, USA.
Background: Patient-reported penicillin allergies are frequently encountered in the emergency department (ED), which often lead to non-beta-lactam antibiotic use despite beta-lactams' place as first-line therapy in most bacterial infections. The PEN-FAST clinical decision tool was developed and validated to identify patients with a low risk of true penicillin allergies that do not require formal skin testing for rechallenging. The tool consists of four questions that add up to a total score ranging from 0 to 5.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Engineering Research Center of Optical Instrument and System, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No.516 Jungong Road, Shanghai, 200093, China.
Background: Surface-enhanced Raman scattering (SERS) has attracted much attention as a powerful detection and analysis tool with high sensitivity and fast detection speed. The intensity of the SERS signal mainly depended on the highly enhanced electromagnetic field of nanostructure near the substrate. However, the fabrication of high-quality SERS nanostructured substrates is usually complicated, makes many methods unsuitable for large-scale production of SERS substrates.
View Article and Find Full Text PDFEBioMedicine
January 2025
Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, New Cornerstone Science Foundation, Beijing, 100084, China. Electronic address:
Background: The widespread and evolution of RNA viruses, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the importance of fast identification of virus subtypes, particularly in non-laboratory settings. Rapid and inexpensive at-home testing of viral nucleic acids with single-base resolution remains a challenge.
Methods: Topologically constrained DNA ring is engineered as substrates for the trans-cleavage of Cas13a to yield an accelerated post isothermal amplification.
Ultrasonics
January 2025
The Center for Fast Ultrasound Imaging, Department of Health Technology. Technical University of Denmark, Ørsteds Plads Building 349, Lyngby, DK-2800, Denmark.
Non-invasive estimation of pressure differences using 2D synthetic aperture ultrasound imaging offers a precise, low-cost, and risk-free diagnostic tool. Unlike invasive techniques, this preserves natural blood flow and avoids the limitations of devices that occupy lumen space. This paper evaluates a previously published estimator, modified to incorporate Singular Value Decomposition (SVD) echo-cancellation, using data from ten healthy volunteers and one patient.
View Article and Find Full Text PDFAnimal
December 2024
PEGASE, INRAE, Institut Agro, 35590 Saint Gilles, France. Electronic address:
During digestion, almost 50% of absorbed essential amino acids (AAs) are metabolised by intestinal tissue, thus not appearing directly in the portal vein. This value, which is referred to as first-pass metabolism, seems high in relation to the overall efficiency of AA use considered in growth models. Experimental studies of first-pass metabolism are complicated due to the presence of numerous metabolic fluxes in the intestine and to the dynamics of digestion and absorption.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!