scholarly journals Identification of stereo rig alignment error based on vertical disparity ma

2019 ◽  
Vol 27 (2) ◽  
Author(s):  
Sandeep Katragadda
Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4137
Author(s):  
Chia-Chang Lee ◽  
Yu-Shen Yen ◽  
Chih-Huang Lai

An alignment-free sensing module for the positioning system based on tunneling magnetoresistive (TMR) sensors with an absolute-incremental-integrated scale is demonstrated. The sensors of the proposed system for both lines consist of identical layer stacks; therefore, all sensors can be fabricated in identical processes from thin film deposition to device patterning on a single substrate. Consequently, the relative position of the sensors can be predefined at the lithography stage and the alignment error between sensors caused by the manual installation is completely eliminated. Different from the existing sensing scheme for incremental lines, we proposed to utilize the magnetic tunnel junctions with a perpendicular anisotropy reference layer and an in-plane anisotropy sensing layer. The sensors are placed parallel to the scale plane with magnetization of the sensing layer in the plane, which show the capability of polarity detection for the absolute line and reveal sinusoidal output signal for the incremental line. Furthermore, due to the large signal of TMR, the working distance can be further improved compared with conventional sensors. In addition, the cost of the positioning system is expected to be lowered, since all the sensors are fabricated in the same process without extra installation. Our design may pave a new avenue for the positioning system based on a magnetic detection scheme.


Author(s):  
Lei Ren ◽  
Ping Shao ◽  
Dongfeng Zhao ◽  
Yang Zhou ◽  
Zhijian Cai ◽  
...  

The Shen-Guang II Upgrade (SG-II-U) laser facility consists of eight high-power nanosecond laser beams and one short-pulse picosecond petawatt laser. It is designed for the study of inertial confinement fusion (ICF), especially for conducting fast ignition (FI) research in China and other basic science experiments. To perform FI successfully with hohlraum targets containing a golden cone, the long-pulse beam and cylindrical hohlraum as well as the short-pulse beam and cone target alignment must satisfy tight specifications (30 and $20~\unicode[STIX]{x03BC}\text{m}$ rms for each case). To explore new ICF ignition targets with six laser entrance holes (LEHs), a rotation sensor was adapted to meet the requirements of a three-dimensional target and correct beam alignment. In this paper, the strategy for aligning the nanosecond beam based on target alignment sensor (TAS) is introduced and improved to meet requirements of the picosecond lasers and the new six LEHs hohlraum targets in the SG-II-U facility. The expected performance of the alignment system is presented, and the alignment error is also discussed.


2013 ◽  
Vol 20 (3) ◽  
pp. 277-281 ◽  
Author(s):  
Aki Tsuruhara ◽  
Hirohiko Kaneko ◽  
So Kanazawa ◽  
Yumiko Otsuka ◽  
Nobu Shirai ◽  
...  

2005 ◽  
Author(s):  
Donglin Xue ◽  
Ligong Zheng ◽  
Xuejun Zhang
Keyword(s):  

2013 ◽  
Vol 66 (5) ◽  
pp. 773-787 ◽  
Author(s):  
Hsin-Hung Chen

An algorithm of alignment calibration for Ultra Short Baseline (USBL) navigation systems was presented in the companion work (Part I). In this part (Part II) of the paper, this algorithm is tested on the sea trial data collected from USBL line surveys. In particular, the solutions to two practical problems referred to as heading deviation and cross-track error in the USBL line survey are presented. A field experiment running eight line surveys was conducted to collect USBL positioning data. The numerical results for the sea trial data demonstrated that the proposed algorithm could robustly and effectively estimate the alignment errors. Comparisons of the experimental result with the analytical prediction of roll misalignment estimation in Part I is drawn, showing good agreement. The experimental results also show that an inappropriate estimation of roll alignment error will significantly degrade the quality of estimations of heading and pitch alignment errors.


10.1167/9.4.3 ◽  
2009 ◽  
Vol 9 (4) ◽  
pp. 3-3 ◽  
Author(s):  
I. Serrano-Pedraza ◽  
J. C. A. Read

1955 ◽  
Vol 53 (4) ◽  
pp. 495-504 ◽  
Author(s):  
K. N. OGLE
Keyword(s):  

Perception ◽  
10.1068/p3440 ◽  
2002 ◽  
Vol 31 (11) ◽  
pp. 1323-1333 ◽  
Author(s):  
Ellen M Berends ◽  
Raymond van Ee ◽  
Casper J Erkelens

It has been well established that vertical disparity is involved in perception of the three-dimensional layout of a visual scene. The goal of this paper was to examine whether vertical disparities can alter perceived direction. We dissociated the common relationship between vertical disparity and the stimulus direction by applying a vertical magnification to the image presented to one eye. We used a staircase paradigm to measure whether perceived straight-ahead depended on the amount of vertical magnification in the stimulus. Subjects judged whether a test dot was flashed to either the left or the right side of straight-ahead. We found that perceived straight-ahead did indeed depend on the amount of vertical magnification but only after subjects adapted (for 5 min) to vertical scale (and only in five out of nine subjects). We argue that vertical disparity is a factor in the calibration of the relationship between eye-position signals and perceived direction.


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