Research on Roadbed Settlement Measurement with Laser Spot Detection Based on Ellipse Fitting

2014 ◽  
Vol 530-531 ◽  
pp. 113-116
Author(s):  
Jing Hong Xing ◽  
Xiang Wei Li ◽  
Lang Tao Zhao
Keyword(s):  
Curve Fitting ◽  
Optical Axis ◽  
Laser Spot ◽  
Ellipse Fitting ◽  
Edge Extraction ◽  
Circle Fitting ◽  
Spot Center ◽  
Spot Detection ◽  
Fitting Algorithm ◽  
Canny Edge

Detecting the location offset of laser spot center method to monitor roadbed settlement is a kind of portable, easy to layout method. Detection laser spot center offset, we can use gravity, circle fitting, ellipse fitting and Gaussian curve fitting, etc method. Gravity algorithm is only involves basic arithmetic and low precise, and ellipse fitting is higher precise. Because of the angle between the optical axis and the target, the laser spot is more approximate as a ellipse. Using the ellipse fitting algorithm, Sub-pixel precise threshold segmentation and Canny edge extraction we obtained an ideal monitoring precise of the roadbed settlement.

An Ellipse Fitting Algorithm Applied to the Construction of the Elliptic Arc-Shaped Leading Edge

2013 ◽  
Vol 744 ◽  
pp. 232-238
Author(s):  
Xiao Qiang Yu ◽  
Tao Ning ◽  
Yong Long Hou ◽  
Zhi Tong Chen
Keyword(s):  
Numerical Experiments ◽  
Leading Edge ◽  
Ellipse Fitting ◽  
Circle Fitting ◽  
Tangential Contact ◽  
Contact Constraint ◽  
Fitting Method ◽  
Fitting Algorithm ◽  
Strong Robustness ◽  
Precision And Accuracy

In this paper, we proposed a new ellipse fitting method converting the ellipse fitting into a circle fitting based on projection transformation. Numerical experiments demonstrate that our approach have good stability and strong robustness against noise in addition to excellent precision and accuracy. In our further research, we successfully extend our algorithm to the construction of the elliptic arc-shaped leading edge by using a tangential contact constraint. Keywords: Ellipse fitting; Projection; PSO; Leading edge

Research on the Recursive and Step-by-Step Algorithm for Extraction of Point Laser Spot Center

2014 ◽  
Vol 1079-1080 ◽  
pp. 991-997
Author(s):  
Xu Xiao Hu ◽  
Ji Li ◽  
Ming Min Yang
Keyword(s):  
Laser Spot ◽  
Second Step ◽  
Circle Fitting ◽  
Step Method ◽  
Centroid Method ◽  
Oil Droplet ◽  
Spot Center ◽  
Fitting Method ◽  
Step Algorithm ◽  
Block Center

Whentesting the flatness of plate iron, if there is no disturbance in the spotdetection, the traditional centroid method and circle fitting method can bewell applied to extract the point laser spot center. However, the disturbanceof droplets, dusts, oil droplet and other factors are unavoidably in thepractical projects, and then the detection precision will falls sharply. In orderto solve the problem, the recursive and step-by-step method of extracting pointlaser spot center is proposed. There are two steps in this method.The thresholdcentroid method is used as the first step to extract the spots which containthe black blocks. The second step is to construct the template whose center hasa black block, then extract the black block center by running phase correlationalgorithm and the center is just the center of the point laser spot. Theresults of experiments verify that the precision of the spot center coordinateextracted by the proposed method is obviously higher than that extracted by thecentroid method and the circle fitting method with the disturbance of droplets.

A Technique to Determine Unsteady-State Inhibition Kinetics in the Activated Sludge Process

1989 ◽  
Vol 21 (6-7) ◽  
pp. 593-602 ◽  
Author(s):  
Andrew T. Watkin ◽  
W. Wesley Eckenfelder
Keyword(s):  
Activated Sludge ◽  
Kinetic Parameters ◽  
Curve Fitting ◽  
Glucose Utilization ◽  
Batch Reactor ◽  
Synthetic Data ◽  
Utilization Rate ◽  
Fitting Algorithm ◽  
Test Reactor ◽  
Two Parameter

A technique for rapidly determining Monod and inhibition kinetic parameters in activated sludge is evaluated. The method studied is known as the fed-batch reactor technique and requires approximately three hours to complete. The technique allows for a gradual build-up of substrate in the test reactor by introducing the substrate at a feed rate greater than the maximum substrate utilization rate. Both inhibitory and non-inhibitory substrate responses are modeled using a nonlinear numerical curve-fitting technique. The responses of both glucose and 2,4-dichlorophenol (DCP) are studied using activated sludges with various acclimation histories. Statistically different inhibition constants, KI, for DCP inhibition of glucose utilization were found for the various sludges studied. The curve-fitting algorithm was verified in its ability to accurately retrieve two kinetic parameters from synthetic data generated by superimposing normally distributed random error onto the two parameter numerical solution generated by the algorithm.

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