measurement path
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Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2155
Author(s):  
Fritz Wilhelm Bopp

Accepting a time-symmetric quantum dynamical world with ontological wave functions or fields, we follow arguments that naturally lead to a two-boundary interpretation of quantum mechanics. The usual two boundary picture is a valid superdeterministic interpretation. It has, however, one unsatisfactory feature. The random selection of a chosen measurement path of the universe is far too complicated. To avoid it, we propose an alternate two-boundary concept called surjective mapping conjecture. It takes as fundamental a quantum-time running forward like the usual time on the wave-function side and backward on the complex conjugate side. Unrelated fixed arbitrary boundary conditions at the initial and the final quantum times then determine the measurement path of the expanding and contracting quantum-time universe in the required way.


2021 ◽  
Vol 11 (20) ◽  
pp. 9507
Author(s):  
Cao-Sang Tran ◽  
Tung-Hsien Hsieh ◽  
Wen-Yuh Jywe

The angular positioning error of the rotary stage causes low quality in milling various angles of a workpiece. This study proposes a solution that could improve these issues by using our Laser R-test for angular positioning calibration and compensation of the five-axis machine tools in compliance with the simultaneous measurement path of ISO regulations: ISO 10791-6 and ISO 230-2. System uncertainty analysis and calibration were implemented for system prediction. The measurement method proposed in this paper could solve concentricity problems between measurement devices and the rotary table by applying the Cosine theorem with a Cartesian coordinate system. Further, we used the commercial instrument XR20-W (Renishaw, UK) rotary axis calibrator to verify and compare the measured results on a CNC machine tool. The applied system achieves an angular error of 0.0121 degrees for actual workpieces and is smaller than the referring commercial system, which achieves an error of about 0.0022 degrees. The system in this research is useful for five-axis machine tool full calibrations.


2021 ◽  
Author(s):  
Zhengcai Zhao ◽  
Yao Li ◽  
Yucan Fu ◽  
Dawei Ding

Measurement path planning plays an essential role in on-machine measurement, which is often required to be time-saving and collision-free. This paper proposes a novel path planning methodology and develops an automatic collision avoidance strategy for measurement. Measurement points are generated by Contour section sampling (CSS), Grid mesh sampling (GMS), and Locally dense sampling (LDS) on the free-form surface. Afterwards, a shortest path algorithm (SPA) and a non-interference path algorithm (NIPA) are developed respectively. The simulations show that the proposed method can reduce the total inspection distance to nearly 7.82% than the original one. The presented path planning method can measure the surface of large aerospace parts directly by using a trigger probe.


2021 ◽  
Vol 11 (10) ◽  
pp. 4707
Author(s):  
Takuya Kishimoto ◽  
Hanwool Woo ◽  
Ren Komatsu ◽  
Yusuke Tamura ◽  
Hideki Tomita ◽  
...  

In this paper, we propose a path planning method for the localization of radiation sources using a mobile robot equipped with an imaging gamma-ray detector, which has a field of view in all directions. The ability to detect and localize radiation sources is essential for ensuring nuclear safety, security, and surveillance. To enable the autonomous localization of radiation sources, the robot must have the ability to automatically determine the next location for gamma ray measurement instead of following a predefined path. The number of incident events is approximated to be the squared inverse proportional to the distance between the radiation source and the detector. Therefore, the closer the distance to the source, the shorter the time required to obtain the same radiation counts measured by the detector. Hence, the proposed method is designed to reduce this distance to a position where a sufficient number of gamma-ray events can be obtained; then, a path to surround the radiation sources is generated. The proposed method generates this path by performing principal component analysis based on the results obtained from previous measurements. Both simulations and actual experiments demonstrate that the proposed method can automatically generate a measurement path and accurately localize radiation sources.


2021 ◽  
Vol 1820 (1) ◽  
pp. 012072
Author(s):  
Zhen Mei ◽  
Lizhe Qi ◽  
Yunquan Sun ◽  
Min Xu

2020 ◽  
Vol 10 (14) ◽  
pp. 4705 ◽  
Author(s):  
Jarosław Figwer ◽  
Małgorzata I. Michalczyk

The idea of active noise control is an attenuation of unwanted noise with an additionally generated acoustic wave using the phenomenon of interference. Its technical realization employs advanced control algorithms. Active noise control is an area of intense research and practical engineering applications. In the paper a new structure of adaptive active noise control systems is proposed. Compared with classical control systems used for active noise control, the proposed structure contains in an error signal measurement path an additional discrete-time filter that estimates signal values at the input of this path. These estimates are then used to tune the corresponding adaptive filter. Properties of the proposed adaptive active noise control structure are illustrated by simulation examples in which a feedforward control system equipped with this additional filter is used to attenuate unwanted wide-sense stationary random noises with continuous and mixed spectra.


Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1075
Author(s):  
Yongkang Wu ◽  
Baoping Lu ◽  
Wei Zhang ◽  
Yandan Jiang ◽  
Baoliang Wang ◽  
...  

Resistivity logging is an important technique for identifying and estimating reservoirs. Oil-based mud (OBM) can improve drilling efficiency and decrease operation risks, and has been widely used in the well logging field. However, the non-conductive OBM makes the traditional logging-while-drilling (LWD) method with low frequency ineffective. In this work, a new oil-based LWD method is proposed by combining the capacitively coupled contactless conductivity detection (C4D) technique and the inductive coupling principle. The C4D technique is to overcome the electrical insulation problem of the OBM and construct an effective alternating current (AC) measurement path. Based on the inductive coupling principle, an induced voltage can be formed to be the indirect excitation voltage of the AC measurement path. Based on the proposed method, a corresponding logging instrument is developed. Numerical simulation was carried out and results show that the logging instrument has good measurement accuracy, deep detection depth and high vertical resolution. Practical experiments were also carried out, including the resistance box experiment and the well logging experiment. The results of the resistance box experiment show that the logging instrument has good resistance measurement accuracy. Lastly, the results of the well logging experiment indicate that the logging instrument can accurately reflect the positions of different patterns on the wellbore of the experimental well. Both numerical simulation and practical experiments verify the feasibility and effectiveness of the new method.


2020 ◽  
Vol 48 (4) ◽  
pp. 745-752
Author(s):  
Slavenko Stojadinović ◽  
Numan Durakbasa ◽  
Saša Živanović

The specific needs of customers set requirements like flexibility and custom-made products, as well as quick placement of products on the markets. Mass customization responds to these requirements and imposes new demands inside manufacturing systems such as optimization and virtualization of machining and measurement processes. A contribution in that direction is presented in this paper, pertaining to development and verification an on-machine measurement planning model. The aim of the verification is to visualize collision check between the measuring head placed in the tool holder and the workpiece on the machine tool working table. The virtual on-machine measurement was realized on the configured virtual machine tool LOLA HBG80 in the CAD environment. The measurement path is generated by a new planning methodology, then optimized using ants colony, programed and verified by simulations through few examples of standard forms of tolerance. The output of the simulation process is the G-code for real on-machine measurement for prismatic parts of medium and rough dimensional accuracy.


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