Hardware Structures for High Precision Pneutronic Systems

2014 ◽  
Vol 658 ◽  
pp. 541-546 ◽  
Author(s):  
Mihai Avram ◽  
Victor Constantin ◽  
Constantin Bucşan ◽  
Daniel Besnea ◽  
Alina Spanu
Keyword(s):  
High Precision ◽  
Weight Ratio ◽  
Nonlinear Behavior ◽  
Compressed Air ◽  
Power Weight ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Large Power ◽  
Pneumatic Actuators ◽  
Positioning Systems

Pneutronic systems come with a series of advantages that are natural to working with compressed air, such as the large power/weight ratio of pneumatic actuators, easy and affordable installation and maintenance as well as being clean working systems. However, due to working with compressed air, there are a series of issues, such as static and transient nonlinear behavior, mostly due to the high compressibility of air. Thus, the behavior of such systems is hard to control, especially in terms of precision positioning. The paper deals with proposing three hardware configurations of pneutronic positioning systems in order to assure the imposed positioning accuracy in the presence of disturbances and the preservation in time of the obtained position.

Issues in validation of pre-sliding friction models for ultra-high precision positioning

2018 ◽  
Vol 233 (3) ◽  
pp. 997-1006 ◽  
Author(s):  
Ervin Kamenar ◽  
Saša Zelenika
Keyword(s):  
High Precision ◽  
Sliding Friction ◽  
Hysteretic Behavior ◽  
Slip Model ◽  
Precision Positioning ◽  
Positioning Systems ◽  
The Real ◽  
Sliding Motion ◽  
Real Behavior ◽  
Friction Models

Friction is one of the main disturbances in nanometric positioning. Recently, it was shown that ultra-high precision positioning typically happens in the pre-sliding motion regime where friction is characterized by an elasto-plastic nonlinear hysteretic behavior with a marked stochastic variability. With the aim of providing the tools for the development of robust control typologies for ultra-high precision mechatronics devices, different pre-sliding friction models are thus considered in this work. The most relevant ones are hence experimentally validated, as well as compared in terms of the complexity of identifying their characteristic parameters and of simulating the factual dynamic response. It is hence shown that the generalized Maxwell-slip model can account for all the important pre-sliding frictional effects in nanometric positioning applications. A thorough sensitivity analysis of the parameters of the generalized Maxwell-slip model model is therefore performed allowing to establish that three Maxwell-slip blocks are the minimum needed to approximate the behavior of the real precision positioning systems, six blocks allow representing excellently the real behavior, while the slower dynamics, which induces a difficult real-time implementation, with a very limited gain in terms of model accuracy, does not justify the usage of a larger number of elements.

The Study Based on LABVIEW of the Positioning Accuracy of Spinneret Microporous Fine Machine

2013 ◽  
Vol 712-715 ◽  
pp. 1347-1350
Author(s):  
Si Yu Liu ◽  
Pei Feng ◽  
Chong Chang Yang
Keyword(s):  
Pore Size ◽  
High Precision ◽  
Vital Role ◽  
Positioning System ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Small Pore Size ◽  
Small Pore ◽  
Positioning Method

The microporous on spinneret has the characteristics of high precision, small pore size and large quantity. Spinneret microporous finishing operation is mainly used for removing the burr formed on the spinneret silk surface after micropores drilling and punching. The burrs seriously affect the quality of the spinning fibers. Micropore spinneret finishing plays a vital role in improving the quality of processing micropore. This paper introduces a system consisting of the spinneret micropore fine machine,then focuses on fine machine positioning system and proposes a high-precision positioning method of the microporous.

scholarly journals Small-Range High-Precision Positioning Based on Two-Point Coordination for Robot

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Zhengping Li ◽  
Chaoliang Qin ◽  
Hao Shi
Keyword(s):  
High Precision ◽  
Sampling Frequency ◽  
Small Range ◽  
Precision Positioning ◽  
Fusion Algorithm ◽  
Positioning Accuracy ◽  
Sinc Interpolation ◽  
Rms Error ◽  
Simulation Results ◽  
Positioning Algorithm

This paper proposed a two-point coordinated positioning algorithm. Based on the assumption that the distance between two points was constant, a fusion algorithm was introduced into the positioning process to enhance the positioning accuracy. The simulation results showed that the proposed algorithm could reduce the RMS error to about 50% of the improved sinc interpolation-based positioning algorithm when the sampling frequency was 500 MHz and the interpolation number was 19.

scholarly journals An Improved Long-Period Precise Time-Relative Positioning Method Based on RTS Data

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 53
Author(s):  
Yangwei Lu ◽  
Shengyue Ji ◽  
Rui Tu ◽  
Duojie Weng ◽  
Xiaochun Lu ◽  
...  
Keyword(s):  
High Precision ◽  
Reference Station ◽  
Positioning Error ◽  
Relative Positioning ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Long Period ◽  
Short Period ◽  
Positioning Method ◽  
Positioning Algorithm

The high precision positioning can be easily achieved by using real-time kinematic (RTK) and precise point positioning (PPP) or their augmented techniques, such as network RTK (NRTK) and PPP-RTK, even if they also have their own shortfalls. A reference station and datalink are required for RTK or NRTK. Though the PPP technique can provide high accuracy position data, it needs an initialisation time of 10–30 min. The time-relative positioning method estimates the difference between positions at two epochs by means of a single receiver, which can overcome these issues within short period to some degree. The positioning error significantly increases for long-period precise positioning as consequence of the variation of various errors in GNSS (Global Navigation Satellite System) measurements over time. Furthermore, the accuracy of traditional time-relative positioning is very sensitive to the initial positioning error. In order to overcome these issues, an improved time-relative positioning algorithm is proposed in this paper. The improved time-relative positioning method employs PPP model to estimate the parameters of current epoch including position vector, float ionosphere-free (IF) ambiguities, so that these estimated float IF ambiguities are used as a constraint of the base epoch. Thus, the position of the base epoch can be estimated by means of a robust Kalman filter, so that the position of the current epoch with reference to the base epoch can be obtained by differencing the position vectors between the base epoch and the current one. The numerical results obtained during static and dynamic tests show that the proposed positioning algorithm can achieve a positioning accuracy of a few centimetres in one hour. As expected, the positioning accuracy is highly improved by combining GPS, BeiDou and Galileo as a consequence of a higher amount of used satellites and a more uniform geometrical distribution of the satellites themselves. Furthermore, the positioning accuracy achieved by using the positioning algorithm here described is not affected by the initial positioning error, because there is no approximation similar to that of the traditional time-relative positioning. The improved time-relative positioning method can be used to provide long-period high precision positioning by using a single dual-frequency (L1/L2) satellite receiver.

Precision Positioning Systems: An Overview of the State of Art

2013 ◽  
Vol 336-338 ◽  
pp. 1170-1173 ◽  
Author(s):  
Francesco Aggogeri ◽  
Alberto Borboni ◽  
Rodolfo Faglia ◽  
Angelo Merlo ◽  
Sara de Cristofaro
Keyword(s):  
High Precision ◽  
Rapid Growth ◽  
The State ◽  
Flexure Hinge ◽  
Actual State ◽  
Positioning System ◽  
Precision Positioning ◽  
Positioning Systems ◽  
Innovative Solutions ◽  
State Of Art

In the industrial world the interest in Precision Positioning Systems is exponentially increasing in relation to the rapid growth of Ultra High Precision (UHP) machining. A greater attention is given to traditional techniques and developing of innovative solutions. This paper intends to present a review of the actual state of art in precision positioning system based on flexure hinge related to industrial machines, showing a comparison between different techniques.

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