Research on Weld Recognition and NURBS Curve Fitting Method Based on Improved OTSU Double Threshold Segmentation

Under the network environment, the traditional control method of underwater Robot path has the disadvantages of low control accuracy, large error, and inefficiency. This paper proposes a novel path control method for underwater Robots based on the NURBS (nonuniform rational B-spline, NURBS) curve fitting method, which utilizes a sensor or camera to detect the static and dynamic obstacles, establishes the kinematics model of underwater Robots, gets the target function of rob shortest path, and analyzes underwater Robot constraints. According to the basic fluid mechanics, the resistance of the underwater Robot is determined. The filter function is used to smooth the process, and the NURBS curve fitting method is applied to control the path of the underwater Robot. Experimental results show that the improved method that proved to be practical is superior to the traditional one in the aspect of control time and accuracy.

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Study on the Method of Expressing the Pitch Curve of Non-Circular Gear Based on NURBS Curve

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.101-102.618 ◽

2011 ◽

Vol 101-102 ◽

pp. 618-622

Author(s):

Xiong Zhao ◽

Jian Neng Chen ◽

Gen Yong Ren ◽

Ying Wang ◽

Chuan Long Li

Keyword(s):

Curve Fitting ◽

Tooth Profile ◽

Solution Model ◽

Detailed Calculation ◽

Nurbs Curve ◽

Specific Solution ◽

Fitting Method ◽

Data Points ◽

Curve Fitting Method ◽

Pitch Curve

In order to express the pitch curve of non-circular gear conveniently in a uniform way, which would lessen the complexity of calculating the tooth profile of non-circular gear, the authors propose a curve fitting method of NURBS curve with the least data points based on the fitting of NURBS curve. This method is used to express the pitch curve of non-circular gear, and the specific solution model and detailed calculation procedure are presented. In addition, a method to select data points inhomogeneously and appropriately using non-uniform factor of selecting points is proposed. Two design examples are introduced to testify the validity of this expression method.

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Hand-Painted Curve Fitting Method Based on NURBS Curve

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1049-1050.1385 ◽

2014 ◽

Vol 1049-1050 ◽

pp. 1385-1388

Author(s):

Shu Qun Liu ◽

Kun Sun

Keyword(s):

Curve Fitting ◽

Modeling Method ◽

Shape Features ◽

Nurbs Curve ◽

Fitting Method ◽

Curve Modeling ◽

Curve Fitting Method

In hand-drawn graphics modeling method, the input to the system free hand draw curve is the first step in modeling. Effective fitting the curve of the input is the key to modeling effect is good or bad. For noise, free shape features of hand-painted curve, presents a method of using NURBS curve fitting of hand-painted curves. Experiments show that using NURBS hand-drawn curve fitting, the fitting effect is good, easy to modify, for later use of curve, not only can be used in hand-painted curve modeling system, can also be applied to the mainstream way of WIMP modeling system.

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Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System Performance

Metrology and Measurement Systems ◽

10.2478/v10178-012-0033-8 ◽

2012 ◽

Vol 19 (2) ◽

pp. 381-394

Author(s):

José Pereira ◽

Octavian Postolache ◽

Pedro Girão

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Measurement System ◽

Curve Fitting ◽

System Performance ◽

Redox Potentials ◽

Voltage Sweep ◽

Gaussian Curve ◽

Fitting Method ◽

Curve Fitting Method

Using A Segmented Voltage Sweep Mode and A Gaussian Curve Fitting Method to Improve Heavy Metal Measurement System PerformanceThis paper presents a voltammetric segmented voltage sweep mode that can be used to identify and measure heavy metals' concentrations. The proposed sweep mode covers a set of voltage ranges that are centered around the redox potentials of the metals that are under analysis. The heavy metal measurement system can take advantage of the historical database of measurements to identify the metals with higher concentrations in a given geographical area, and perform a segmented sweep around predefined voltage ranges or, alternatively, the system can perform a fast linear voltage sweep to identify the voltammetric current peaks and then perform a segmented voltage sweep around the set of voltages that are associated with the voltammetric current peaks. The paper also includes the presentation of two auto-calibration modes that can be used to improve system's reliability and proposes the usage of a Gaussian curve fitting of voltammetric data to identify heavy metals and to evaluate their concentrations. Several simulation and experimental results, that validate the theoretical expectations, are also presented in the paper.

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