scholarly journals Visual Calibration for Multiview Laser Doppler Speed Sensing

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 582 ◽  
Author(s):  
Yunpu Hu ◽  
Leo Miyashita ◽  
Yoshihiro Watanabe ◽  
Masatoshi Ishikawa

We present a novel calibration method for a multi-view laser Doppler speed sensing (MLDSS) system. In contrast with the traditional method where only the laser geometry is independently calibrated, the proposed method simultaneously optimizes all the laser parameters and directly associates the parameters with a motion sensing model. By jointly considering the consistency among laser Doppler velocimetry, the laser geometry and a visual marker tracking system, the proposed calibration method further boosts the accuracy of MLDSS. We analyzed the factors influencing the precision, and quantitatively evaluated the efficiency of the proposed method on several data sets.

1997 ◽  
Vol 36 (5) ◽  
pp. 61-68 ◽  
Author(s):  
Hermann Eberl ◽  
Amar Khelil ◽  
Peter Wilderer

A numerical method for the identification of parameters of nonlinear higher order differential equations is presented, which is based on the Levenberg-Marquardt algorithm. The estimation of the parameters can be performed by using several reference data sets simultaneously. This leads to a multicriteria optimization problem, which will be treated by using the Pareto optimality concept. In this paper, the emphasis is put on the presentation of the calibration method. As an example identification of the parameters of a nonlinear hydrological transport model for urban runoff is included, but the method can be applied to other problems as well.


2021 ◽  
Vol 1909 (1) ◽  
pp. 012075
Author(s):  
Daisuke Sugiyama ◽  
Asuma Ichinose ◽  
Tomoki Takeda ◽  
Kazuyoshi Miyagawa ◽  
Hideyo Negishi ◽  
...  

2001 ◽  
Vol 7 (3) ◽  
pp. 173-181
Author(s):  
Tong-Miin Liou ◽  
Meng-Yu Chen

Laser-Doppler velocimetry (LDV) measurements are presented of relative mean velocity and turbulence intensity components inside the impeller passage of a centrifugal fan with twelve backward curved blades at design, under-design, and over-design flow rates. Additional LDV measurements were also performed at the volute outlet to examine the uniformity of the outlet flow for the three selected flow rates. Complementary flow visualization results in the tongue region are further presented. It is found that the number of characteristic flow regions and the average turbulence level increase with decreasing air flow rate. For the case of under-design flow rate, there are a through-flow region on the suction side, a reverse flow region on the pressure side, and a shear layer region in between. The corresponding average turbulence intensity is as high as 9.1% of blade tip velocity.


2011 ◽  
Vol 52 (4) ◽  
pp. 1017-1026 ◽  
Author(s):  
Alexander H. Meier ◽  
Thomas Roesgen

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