Precision mechatronics based on high-precision measuring and positioning systems and machines

2007 ◽  
Author(s):  
Gerd Jäger ◽  
Eberhard Manske ◽  
Tino Hausotte ◽  
Rostyslav Mastylo ◽  
Natalja Dorozhovets ◽  
...  
Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3701
Author(s):  
Ju-Hyeon Seong ◽  
Soo-Hwan Lee ◽  
Won-Yeol Kim ◽  
Dong-Hoan Seo

Wi-Fi round-trip timing (RTT) was applied to indoor positioning systems based on distance estimation. RTT has a higher reception instability than the received signal strength indicator (RSSI)-based fingerprint in non-line-of-sight (NLOS) environments with many obstacles, resulting in large positioning errors due to multipath fading. To solve these problems, in this paper, we propose high-precision RTT-based indoor positioning system using an RTT compensation distance network (RCDN) and a region proposal network (RPN). The proposed method consists of a CNN-based RCDN for improving the prediction accuracy and learning rate of the received distances and a recurrent neural network-based RPN for real-time positioning, implemented in an end-to-end manner. The proposed RCDN collects and corrects a stable and reliable distance prediction value from each RTT transmitter by applying a scanning step to increase the reception rate of the TOF-based RTT with unstable reception. In addition, the user location is derived using the fingerprint-based location determination method through the RPN in which division processing is applied to the distances of the RTT corrected in the RCDN using the characteristics of the fast-sampling period.


Author(s):  
S. Tiguntsev

In classical physics, time is considered absolute. It is believed that all processes, regardless of their complexity, do not affect the flow of time The theory of relativity determines that the flow of time for bodies depends both on the speed of movement of bodies and on the magnitude of the gravitational potential. It is believed that time in space orbit passes slower due to the high speed of the spacecraft, and faster due to the lower gravitational potential than on the surface of the Earth. Currently, the dependence of time on the magnitude of the gravitational potential and velocity (relativistic effect) is taken into account in global positioning systems. However, studying the relativistic effect, scientists have made a wrong interpretation of the difference between the clock frequency of an orbiting satellite and the clock frequency on the Earth's surface. All further studies to explain the relativistic effect were carried out according to a similar scenario, that is, only the difference in clock frequencies under conditions of different gravitational potentials was investigated. While conducting theoretical research, I found that the frequency of the signal changes along the way from the satellite to the receiver due to the influence of Earth's gravity. It was found that the readings of two high-precision clocks located at different heights will not differ after any period of time, that is, it is shown that the flow of time does not depend on the gravitational potential. It is proposed to conduct full-scale experiments, during which some high-precision clocks are sent aboard the space station, while others remain in the laboratory on the surface of the earth. It is expected that the readings of the satellite clock will be absolutely identical to the readings of the clock in the Earth laboratory.


Author(s):  
Ervin Kamenar ◽  
Saša Zelenika

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.


1997 ◽  
Author(s):  
Ipek Basdogan ◽  
Thomas J. Royston ◽  
Ahmed A. Shabana ◽  
Juan Barraza, Jr. ◽  
Deming Shu ◽  
...  

2015 ◽  
Vol 731 ◽  
pp. 340-344
Author(s):  
Qian Ru Tian ◽  
Bang Gui He ◽  
Zhi Long Wang

Precision of filter rod circumference is an important performance index of the cigarette manufacturing. The forming mechanism of filter rod, equipment vibration and other interference factors all lead to fluctuations of precision of filter rod circumference which can affect the precision of the cigarette. The existing KDF2/3 filter rod making machine which has the characteristics of compact structure (small space dimension), high speed (300 m/min) and discrete control of precision of filter rod circumference is the core equipment of filter rod production. This paper puts forward four kinds of online real-time detection schemes on precision of filter rod circumference which are Aomeijia’s many groups of detectors scheme, Keyence’s contour detection scheme, high precision measuring diameter instrument detection scheme using multiple sets of KD series meter and the 360 degrees rotating survey meter. On the basis of extensive analysis and experimental validation, Aomeijia’s four-way diameter measuring instrument scheme is optimal. The scheme applies laser to non-contact high speed scan on key radial diameter size of filter rod which achieves 0.001mm high precision detection.


Sign in / Sign up

Export Citation Format

Share Document