scholarly journals Pseudorandom position encoder with improved zero position adjustment

2012 ◽  
Vol 25 (2) ◽  
pp. 113-120
Author(s):  
Dragan Denic ◽  
Goran Miljkovic ◽  
Jelena Lukic ◽  
Miodrag Arsic
Keyword(s):  
Adjustment Process ◽  
Motor Shaft ◽  
Position Measurement ◽  
Absolute Position ◽  
Motion Direction ◽  
Sensor Head ◽  
Functional Algorithm ◽  
Zero Position ◽  
Reliable Procedure ◽  
The Absolute

Pseudorandom position encoder, which employs two code tracks for absolute position measurement, represents one of the latest trends in the development of the absolute position encoders. One sensor head is used for pseudorandom code reading and two additional sensor heads are used for generating synchronization pulses and motion direction determination. Special attention is devoted to the zero position adjustment after the installation of the encoder on the motor shaft. A novel solution for the improved zero position adjustment incorporated in the functional algorithm of the encoder is presented in this paper. The presented solution offers a reliable procedure for the zero position adjustment, taking into account possible motion direction changes during the zero position adjustment process. The algorithm for the zero position adjustment executes only once and does not participate further in the absolute position measurement process. The functioning of the proposed algorithm is described in more details considering one concrete example of the encoder.

Experimental Study on Application of DGPS-based Position Information to Automatic Driving Control

2001 ◽  
Vol 13 (4) ◽  
pp. 340-351 ◽  
Author(s):  
Manabu Omae ◽  
◽  
Takehiko Fujioka ◽  
Keyword(s):  
Control System ◽  
Experimental Studies ◽  
Time Estimation ◽  
Position Measurement ◽  
Absolute Position ◽  
Position Information ◽  
Automatic Driving ◽  
Automatic Steering ◽  
The Absolute ◽  
Estimation And Control

Experimental studies are conducted for investigating the possibility of automatic driving control systems based on absolute position information. Implementation of such control system requires a methodology of measuring the absolute position, and a control algorithm. In this paper, an accurate and real-time estimation of the absolute position by use of DGPS (Differential Global Positioning System) and sensors on a controlled vehicle is proposed. Automatic steering controller, automatic evasive controller, and a method of relative position measurement of neighboring vehicles are also proposed as application of position information to automatic driving control. Experiments are conducted using sedan-type vehicles. Experimental results validate the proposed estimation and control system, and provide the perspective of enhancing the automatic driving control system by use of the absolute position information.

Development of a simultaneous imaging system to measure the optical and gamma ray images of Ir-192 source for high-dose-rate brachytherapy

2021 ◽  
Vol 16 (12) ◽  
pp. T12005
Author(s):  
J. Nagata ◽  
S. Yamamoto ◽  
Y. Noguchi ◽  
T. Nakaya ◽  
K. Okudaira ◽  
...  
Keyword(s):  
Dose Rate ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Gamma Ray ◽  
Imaging System ◽  
High Dose Rate ◽  
High Dose ◽  
Cmos Camera ◽  
Absolute Position ◽  
The Absolute

Abstract In high-dose-rate (HDR) brachytherapy, verification of the Ir-192 source's position during treatment is needed because such a source is extremely radioactive. One of the methods used to measure the source position is based on imaging the gamma rays from the source, but the absolute position in a patient cannot be confirmed. To confirm the absolute position, it is necessary to acquire an optical image in addition to the gamma ray image at the same time as well as the same position. To simultaneously image the gamma ray and optical images, we developed an imaging system composed of a low-sensitivity, high-resolution gamma camera integrated with a CMOS camera. The gamma camera has a 1-mm-thick cerium-doped yttrium aluminum perovskite (YAIO3: YAP(Ce)) scintillator plate optically coupled to a position-sensitive photomultiplier (PSPMT), and a 0.1-mm-diameter pinhole collimator was mounted in front of the camera to improve spatial resolution and reduce sensitivity. We employed the concept of a periscope by placing two mirrors tilted at 45 degrees facing each other in front of the gamma camera to image the same field of view (FOV) for the gamma camera and the CMOS camera. The spatial resolution of the imaging system without the mirrors at 100 mm from the Ir-192 source was 3.2 mm FWHM, and the sensitivity was 0.283 cps/MBq. There was almost no performance degradation observed when the mirrors were positioned in front of the gamma camera. The developed system could measure the Ir-192 source positions in optical and gamma ray images. We conclude that the developed imaging system has the potential to measure the absolute position of an Ir-192 source in real-time clinical measurements.

scholarly journals Glacial Geodetic Contributions to the Mass Balance and Dynamics of Ice Shelves

1988 ◽  
Vol 11 ◽  
pp. 89-94 ◽  
Author(s):  
D. Möller ◽  
B. Ritter
Keyword(s):  
Mass Balance ◽  
Collocation Method ◽  
Ice Shelf ◽  
Absolute Position ◽  
Ice Flow ◽  
Ice Shelves ◽  
Rotation Rates ◽  
Deformation Parameters ◽  
Satellite Methods ◽  
The Absolute

The glacial geodetic contribution to the mass balance and dynamics of ice shelves includes repeated determinations of the absolute position (ϕ,λ,Η) of selected points (using satellite methods), the establishment of relative positions (y,x,Δh) in deformation figures, and height measurements. The results are used to establish ice-flow velocities and directions, strain and rotation rates, and changes in height. Modelling of deformation parameters at a few points over a large ice shelf is made possible by the collocation method. Results of these observations and analysis of Ekström Ice Shelf for the period 1979–87 are reported.

A simple low-coherence interferometric sensor for absolute position measurement based on central fringe maximum identification

2012 ◽  
Vol T149 ◽  
pp. 014023 ◽  
Author(s):  
L M Manojlović ◽  
M B Živanov ◽  
M P Slankamenac ◽  
D Z Stupar ◽  
J S Bajić
Keyword(s):  
Position Measurement ◽  
Absolute Position ◽  
Low Coherence ◽  
Interferometric Sensor

scholarly journals VLBA H2O and SiO maser observations in the pPN OH 231.8+4.2

2007 ◽  
Vol 3 (S242) ◽  
pp. 338-339
Author(s):  
J.-F. Desmurs ◽  
C. Sánchez Contreras ◽  
V. Bujarrabal ◽  
J. Alcolea ◽  
F. Colomer
Keyword(s):  
High Resolution ◽  
Water Vapour ◽  
Planetary Nebulae ◽  
Absolute Position ◽  
Long Baseline ◽  
The Absolute ◽  
Very Long Baseline Array

AbstractWe report high-resolution observations of H2O, 61,6−52,3 and 28SiO v=2, J=1-0 maser emissions obtained with the Very Long Baseline Array in the bipolar pre-planetary nebulae OH 231.8+4.2 (see Desmurs et al., 2007). A phase referencing technique was used to recover the absolute position of both emissions. We detected two groups of water vapour emission oriented nearly north-south. SiO masers are tentatively found to be placed between the two H2O maser emitting regions.

scholarly journals A construction-based cross-linguistic analysis of V2 word order

2011 ◽  
Author(s):  
Andrew C. Wetta
Keyword(s):  
Word Order ◽  
Linguistic Analysis ◽  
Verb Second ◽  
Absolute Position ◽  
Topological Domains ◽  
The Absolute

Verb second (V2) word order is determined by considering the absolute position of clausal constituents. Previous accounts of such word order in HPSG have been developed for individual V2 languages (predominantly German) but are often not cross-linguistically applicable. I propose a set of generalized mechanisms in linearization-based SBCG which accounts for cross-linguistic V2 data by use of: (1) a simple two-valued feature rather than many-typed topological domains, (2) domain compaction, and (3) constructionally-determined domain positions. Not only does this analysis account for V2 placement, but it can also model verb third (V3) placement and other positionally-stipulated word orders.

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