Estimation of Posture and Position Based on Geometric Calculation Using IMUs

2019 ◽  
Author(s):  
Yumiko Murata ◽  
Toshiyuki Murakami
Keyword(s):  
Geometric Calculation

Features of geometric design of planetary rotary hydraulic machines with satellite stands

2020 ◽  
pp. 472-478
Author(s):  
D.V. Fadyushin ◽  
G.Yu. Volkov
Keyword(s):  
Three Dimensional ◽  
Geometric Design ◽  
Design System ◽  
Link Mechanism ◽  
Hydraulic Machines ◽  
New Type ◽  
Geometric Calculation

А method of geometric calculation of a new type of planetary rotary hydraulic machines (PRGM) with satellite stands is developed. The method includes the steps of: 1) calculation of the initial round-link mechanism; 2) calculation of non-round links of the PRGM with outstretches; 3) construction and integration of three-dimensional design system COMPAS-3D fragments of crenellated crowns corresponding to the phases of abutments and lifting-lowering satellites; 4) correction of the toothed contours to eliminate the phenomenon of mismatch of satellite centers with the points of intersection of the trajectories of these centers in their movement relative to the rotor and stator. PRGM with satellite stands are designed to operate as vacuum pumps, compressors and pneumatic motors.

scholarly journals Estimating camera parameters from starry night photographs

2020 ◽  
Vol 6 (4) ◽  
pp. 445-454
Author(s):  
Naoto Ishikawa ◽  
Yoshinori Dobashi
Keyword(s):  
Input Image ◽  
Previous Method ◽  
Estimation Methods ◽  
Specific Method ◽  
Star Catalog ◽  
Geometric Calculation ◽  
Camera Parameters ◽  
Celestial Sphere

AbstractWe propose an efficient, specific method for estimating camera parameters from a single starry night image. Such an image consists of a collection of disks representing stars, so traditional estimation methods for common pictures do not work. Our method uses a database, a star catalog, that stores the positions of stars on the celestial sphere. Our method computes magnitudes (i.e., brightnesses) of stars in the input image and uses them to find the corresponding stars in the star catalog. Camera parameters can then be estimated by a simple geometric calculation. Our method is over ten times faster and more accurate than a previous method.

GEOMETRIC CALCULATION OF THE PLANETARY MECHANISM WITH THE EQUAL NUMBER OF TEETH OF THE EXTERNAL AND INTERNAL SUN GEAR

2020 ◽  
pp. 27-31
Author(s):  
G. Yu. Volkov ◽  
D. V. Fadyushin
Keyword(s):  
Positive Displacement ◽  
Number Of Teeth ◽  
Hydraulic Machines ◽  
Geometric Calculation ◽  
Planetary Mechanism

The article proposes a method for geometric calculation of gear links of planetary mechanisms in which the central wheels of external and internal gearing have the same number of teeth. The key to solving the problem is the existing possibility of a large positive displacement of the tool when machining the crown with internal involute teeth. The calculation used the formulas GOST 16532–70 and GOST 19274–73, arranged in a certain sequence. The planetary mechanisms under consideration underlie the new volumetric rotary hydraulic machines.

Shape Formation of Stereometric Dome Shells

1992 ◽  
Vol 7 (1) ◽  
pp. 39-60 ◽  
Author(s):  
V.V. Zubkov
Keyword(s):  
Point Of View ◽  
Shape Formation ◽  
Regular Configuration ◽  
Geometric Calculation ◽  
Material Utilisation

Theoretical fundamentals of shape formation of stereometrical dome shells are revealed in this article. The genesis of shapes of shells consisting of plane elements of regular configuration in the form of truncated parts of regular polyhedrons is also considered. Principles of geometric formation of shell shapeil structures are touched upon and a brief description of each of them is given from the point of view of possible unification of shape forming elements. The author develops a methodology for designing stereometrical dome-shaped shells on the basis of regular crystals. He also describes methods of geometric calculation of stereometrical dome-shaped shells. Some methods of construction of shell surfaces and various kinds of compositions derived from them are demonstrated. Brief data on the peculiarities of material utilisation of stereometrical dome shells and some examples of their application in architecture are given.

Improving gap light index (GLI) to quickly calculate gap coordinates

2008 ◽  
Vol 38 (9) ◽  
pp. 2337-2347 ◽  
Author(s):  
Lile Hu ◽  
Jiaojun Zhu
Keyword(s):  
Canopy Gap ◽  
Canopy Height ◽  
Gap Size ◽  
Light Regimes ◽  
Light Levels ◽  
Understory Plants ◽  
Sampling Points ◽  
Hemispherical Photographs ◽  
Geometric Calculation

Understory light is essential to the establishment and growth of understory plants and varies temporally and spatially within gaps. The previously defined gap light index (GLI) is a good model for assessing understory light levels, but it is time-consuming to determine gap coordinates, which are crucial to GLI, for numerous points within a gap. This paper introduces the geometric calculation (GeoCalc) of gap coordinates. GeoCalc quickly obtains gap coordinates for any specified point within a canopy gap and takes into account the tridimensional profile of the gap and the slope and aspect of the ground. The GeoCalc-based GLI was validated by the GLI derived from hemispherical photographs taken at 93 sampling points within seven natural gaps. Our results demonstrate that GeoCalc-based GLI was strongly positively correlated and not significantly differed from the GLI derived from hemispherical photographs. Next, to analyze gap light regimes and the effects of gap size, canopy height, and topography, three natural gaps of various size were selected and simulated as nine gaps with 1 and 1.5 times canopy height or on the opposite slope. Finally, we have summarized characteristics of GeoCalc-based GLI and its application.

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