High Precision Hydrostatic Actuation Systems for Micro- and Nanomanipulation of Heavy Loads

2005 ◽  
Vol 128 (4) ◽  
pp. 778-787 ◽  
Author(s):  
Saeid Habibi ◽  
Richard Burton ◽  
Eric Sampson
Keyword(s):  
High Precision ◽  
Experimental Results ◽  
Positional Accuracy ◽  
Large Load ◽  
Actuation System ◽  
Heavy Loads ◽  
Actuation Systems ◽  
Laboratory Prototype ◽  
Electrohydraulic Actuator

In this paper reports on an important finding, that is, hydrostatic actuation systems are able to manipulate heavy loads with submicron precision and a large stroke. In this relation, the design of a high-precision hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA) is presented. A laboratory prototype of this system has achieved an unprecedented level of performance by being able to move a large load of 20Kg with a precision of 100nm and a stroke of 12cm. This level of performance places the hydrostatic actuation concept in competition with piezoelectric platforms in terms of positional accuracy. Experimental results from this prototype are reported and analyzed.

Micro-Precision Hydrostatic Actuation System

2005 ◽  
Author(s):  
S. R. Habibi ◽  
R. Burton ◽  
E. Sampson
Keyword(s):  
High Precision ◽  
Experimental Results ◽  
Positional Accuracy ◽  
Large Load ◽  
Actuation System ◽  
Heavy Loads ◽  
Actuation Systems ◽  
Laboratory Prototype ◽  
Electrohydraulic Actuator

This paper reports on an important discovery that is: hydrostatic actuation systems are able to manipulate heavy loads with sub-micron precision and large stroke. In this relation, the design of a high-precision hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA) is presented. A laboratory prototype of this system has achieved an unprecedented level of performance by being able to move a large load of 20Kg with a precision of 50 nanometers and a stroke of 12cm. This level of performance places the hydrostatic actuation concept in competition with piezoelectric platforms in terms positional accuracy. Experimental results from this prototype are reported and analyzed.

scholarly journals How the Multiplicity of Suggested Information Affects the Behavior of a User in a Recommender System

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 741
Author(s):  
Yuseok Ban ◽  
Kyungjae Lee
Keyword(s):  
High Precision ◽  
Recommender System ◽  
Visual Information ◽  
Experimental Results ◽  
Supplementary Information ◽  
Digital Platform ◽  
Different Types ◽  
Types Of Information

Many researchers have suggested improving the retention of a user in the digital platform using a recommender system. Recent studies show that there are many potential ways to assist users to find interesting items, other than high-precision rating predictions. In this paper, we study how the diverse types of information suggested to a user can influence their behavior. The types have been divided into visual information, evaluative information, categorial information, and narrational information. Based on our experimental results, we analyze how different types of supplementary information affect the performance of a recommender in terms of encouraging users to click more items or spend more time in the digital platform.

Implementation of a High-Precision Ultrasonic Rain Gauge

2013 ◽  
Vol 300-301 ◽  
pp. 382-388
Author(s):  
Zhan Wei Xu ◽  
Gui Lin Zheng
Keyword(s):  
Theoretical Analysis ◽  
High Precision ◽  
Rain Gauge ◽  
Experimental Results ◽  
Full Description ◽  
Self Calibration ◽  
Velocity Of Ultrasound

A novel rain gauge based on acoustic self-calibration principle is proposed in the paper. Acoustic self-calibration principle can eliminate the uncertainty of the velocity of ultrasound and achieve accurate measurement of rainfall. The rain gauge not only overcomes the influence on the rainfall measurement under intensive rainfall conditions, but also improves the precision of rain gauge. Plenty of experiments have been done to validate the design. Both theoretical analysis and experimental results show the effectiveness of the rain gauge. A full description of the rain gauge and implementation are presented.

Friction and Tribological Considerations for Nanometer Range Machining

2001 ◽  
Author(s):  
Som Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
High Precision ◽  
Local Deformation ◽  
Experimental Results ◽  
Precision Machining ◽  
Complex Motion ◽  
Positioning Accuracy ◽  
Nanometer Range ◽  
Motion Characteristic ◽  
Low Speeds

Abstract Positioning accuracy within the range of nanometers is required for high precision machining applications. The implementation of such a range is difficult through the slides because of (a) irregular nature of friction at the slider-guideway interface, and (b) complex motion characteristic at very low speeds. The complexity arises due to the local deformation at the interface prior to breakaway, which is known as microdynamics. In this work prior experimental results exhibiting microdynamics have been appraised, and mathematical model developed to understand this behavior.

Design, modeling, and analysis of wedge-based actuator with application to clutch-to-clutch shift

2017 ◽  
Vol 232 (9) ◽  
pp. 1149-1166
Author(s):  
Fengyu Liu ◽  
Li Chen ◽  
Jian Yao ◽  
Chunhao Lee ◽  
Chi-kuan Kao ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Fast Response ◽  
Physical Structure ◽  
Modeling And Analysis ◽  
Shift Quality ◽  
Actuation System ◽  
Automatic Transmissions ◽  
Potential Alternative ◽  
Low Efficiency ◽  
Actuation Systems

Clutch-to-clutch shift technology is a key enabler for fast and smooth gear shift process for multi gear transmissions. However, conventional hydraulic actuation systems for clutches have drawbacks of low efficiency, oil leakage and inadequate robustness. Electromechanical devices offer potential alternative actuators. In this paper, a novel motor driven wedge-based clutch actuator, featuring self-reinforcement, is proposed. The design concept and physical structure are thoroughly described. Dynamic models for the actuation system and vehicle powertrain are validated by experiments. Upshift and downshift processes at different engine throttle openings, clutch clearances and friction coefficients are discussed. The results show that, the self-reinforcement ratio is tested as 9.6; at the same time, the shift quality is comparable to that of the conventional hydraulic actuated clutch in automatic transmissions in terms of the shift duration (about 1 s) and vehicle jerk (<10 m/s3). Taking advantage of fast response of the actuation DC motor, the wedge-based actuator is robust dealing with uncertain clutch clearance and friction coefficient. Therefore, the wedge-based clutch actuator has potential to provide acceptable performance for clutch-to-clutch shift.

Active fault-tolerant control for vertical tail damaged aircraft with dissimilar redundant actuation system using integral sliding mode control

2018 ◽  
Vol 233 (7) ◽  
pp. 2361-2378 ◽  
Author(s):  
Salman Ijaz ◽  
Mirza T Hamayun ◽  
Lin Yan ◽  
Cun Shi
Keyword(s):  
Actuator Saturation ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Fault Estimation ◽  
Redundant Actuation ◽  
Severe Damage ◽  
Integral Sliding Mode ◽  
Actuation System ◽  
Electrohydraulic Actuator

The research about the dissimilar redundant actuation system has indicated the potential fault-tolerant capability in modern aircraft. This paper proposed a new design methodology to achieve fault-tolerant control of an aircraft equipped with dissimilar actuators and is suffered from vertical tail damage. The proposed design is based on the concept of online control allocation to redistribute the control signals among healthy actuators and integral sliding mode controller is designed to achieve the closed-loop stability in the presence of both component and actuator faults. To cope with severe damage condition, the aircraft is equipped with dissimilar actuators (hydraulic and electrohydraulic actuators). In this paper, the performance degradation due to slower dynamics of electrohydraulic actuator is taken in account. Therefore, the feed-forward compensator is designed for electrohydraulic actuator based on fractional-order control strategy. In case of failure of hydraulic actuator subject to severe damage of vertical tail, an active switching mechanism is developed based on the information of fault estimation unit. Additionally, a severe type of actuator failure so-called actuator saturation or actuator lock in place is also taken into account in this work. The proposed strategy is compared with the existing control strategies in the literature. Simulation results indicate the dominant performance of the proposed scheme. Moreover, the proposed controller is found robust with a certain level of mismatch between the actuator effectiveness level and its estimate.

scholarly journals Non-Conventional Actuation Mechanisms used in Mechatronic systems

2018 ◽  
Vol 3 (1) ◽  
pp. 05-10
Author(s):  
Rajiv Chaudhary ◽  
◽  
Alok Kumar Singh
Keyword(s):  
Mechanical Systems ◽  
Recent Past ◽  
Mechatronic Systems ◽  
Actuation System ◽  
Prime Movers ◽  
Overall Performance ◽  
Engine System ◽  
Mechanical Elements ◽  
Actuation Systems ◽  
Mechanical Actuation

Tracking the path of development in different Engineering disciplines, it can be easily observed that, right from the primitive stage, several tools, devices, and techniques may be identified, which happened by virtue of the evolution of human intelligence, getting transformed into various engineering applications. Although, later different engineering disciplines evolved, where most of the exhaustive development could be undertaken in that discipline. Likewise, in the field of mechanical engineering to various types of mechanical systems, according to the requirement in that field, were developed, in order to provide support of mechanization. Prime movers used to be an important part of these mechanical systems, which provided energy input as well as actuation required for providing the machines the desired kinematics. Most of the mechanical systems developed has been operated by conventional engine system using one or other fuel. Apart from the actuation by mechanical means, there are other means also through which mechanical actuation with better control, flexibility, and manipulation may be utilized in mechanical systems. A different category of systems, called Mechatronic systems has been developed in the recent past, which involves the vivid scope of use of techniques, devices, and components generally used in various other engineering fields of electrical, electronics, hydraulics, and pneumatics, etc. Subsequently, there have been several inventions, design & development which have added new levels in every field. Mechanical systems have been generally composed of various mechanical elements, which are designed to follow certain kinematics. The performance of the Actuation system plays an important role in the overall performance of the mechanical systems. There are several alternative actuation systems, which are not mechanical. These actuation systems may be categorized into electrical, electronics, hydraulic and pneumatic types. The features of these actuation systems, are so peculiar, that typical kinematic movement may be manipulated that too with more precision. Better control of mechanical systems may be realized, which is otherwise difficult with mechanical systems. In this paper, an effort has been made to review the possibilities, prospects as well as scope with various actuation systems.

Local and Global Latent Semantic Analysis for Text Categorization

2014 ◽  
Vol 4 (3) ◽  
pp. 1-13
Author(s):  
Khadoudja Ghanem
Keyword(s):  
Information Retrieval ◽  
High Precision ◽  
Latent Semantic Analysis ◽  
Classification Accuracy ◽  
Text Categorization ◽  
Semantic Analysis ◽  
Experimental Results ◽  
Semantic Approach ◽  
Document Categorization ◽  
Second Use

In this paper the authors propose a semantic approach to document categorization. The idea is to create for each category a semantic index (representative term vector) by performing a local Latent Semantic Analysis (LSA) followed by a clustering process. A second use of LSA (Global LSA) is adopted on a term-Class matrix in order to retrieve the class which is the most similar to the query (document to classify) in the same way where the LSA is used to retrieve documents which are the most similar to a query in Information Retrieval. The proposed system is evaluated on a popular dataset which is 20 Newsgroup corpus. Obtained results show the effectiveness of the method compared with those obtained with the classic KNN and SVM classifiers as well as with methods presented in the literature. Experimental results show that the new method has high precision and recall rates and classification accuracy is significantly improved.

scholarly journals Experimental Comparison of Outdoor Baseline Measurements by Different Methods

2019 ◽  
Vol 131 ◽  
pp. 01057
Author(s):  
Youyi Gu ◽  
Li Wang ◽  
Fengzhuo Xiang ◽  
Wen Ouyang ◽  
Lixing Jiang
Keyword(s):  
Direct Measurement ◽  
High Precision ◽  
Optical Measurement ◽  
Experimental Results ◽  
Experimental Comparison ◽  
Total Station ◽  
Length Standard ◽  
Gnss Receivers ◽  
Surveying And Mapping

Outdoor baseline is the special length standard in the field of surveying and mapping, it can be used to verify the addition and multiplication constants of the total station and other photoelectric rangefinders. In order to ensure the authenticity, accuracy and reliability of verification results, conducting outdoor baseline traceability periodically is essential. At present, direct measurement by 24m invar tape or high precision electro-optical measurement is mainly used to achieve the traceability of outdoor baseline in China. Based on Shenyang baseline field, high precision rangefinder μ-base, 24m invar tape and high precision GNSS receivers are used for comparison experiments, and the experimental results are analyzed.

scholarly journals The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results

2007 ◽  
Vol 264 (2-3) ◽  
pp. 110-121 ◽  
Author(s):  
S. George ◽  
K. Blaum ◽  
F. Herfurth ◽  
A. Herlert ◽  
M. Kretzschmar ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Precision ◽  
Experimental Results ◽  
Penning Traps
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