Advanced Materials Research Vols. 301-303

Abstract: Noise detection-based median filters have been widely adopted to reduce salt and pepper noise in images. However, since noise pixel is not detected accurately, it is likely to blur the fringe of image under the high noise density. In this paper, we propose an algorithm of salt and pepper noise filter which is based on GA-BP algorithm noise detector to remove the salt and pepper noise in images. The algorithm firstly detect the location of noise pixels by using optimized GA-BP network,then,it introduce edge-preserving function and PRP algorithm to solve the objective function of extreme value further to realize the image denoising. Compared with the traditional algorithms, experimental results show that the proposed algorithm has an evident improvement, and have good characters of generalization, robust and self-adaptive.

Abstract: Frontal sled test is an important platform that widely employed to predict and assess changes in overall safety performance as vehicle structural and occupant restraint parameters are varied. In this paper, a characteristic door intrusion velocity pulse in side impact was analyzed and a set of side test jig was designed, which realized one kind of simplified side impact sled test method. Then we compared the injury values of the side impact dummy, the result showed that there existed good correlation between sled test and full-vehicle test.

Abstract: In this paper, local variance is used to describe the structural information of a color image in order to assess its quality. The representation method is different from conventional models in that some information that is sensitive to human eyes is enhanced by using local variance distribution. It encodes the local variance distribution of different channels of a color image into the three imaginary parts of a quaternion. The distance between the singular value feature vectors of the source image block and the distorted image block which are described by quaternion matrices is calculated. The experimental results show that the assessment results of the proposed assessment method are more consistent with the Human Visual System than those of the conventional assessment methods.

Abstract: To understand more about Lamb waves on composite laminates damage detection features, the Lamb wave group velocity dispersion curves are calculated and plotted by using dichotomy method in MATLAB. The signal parameters are chosen according to Group velocity dispersion curves. The dynamic response signals of the composite plate are obtained by finite element method. Damage location is calculated by the actual group velocity of Lamb wave and time of flight of the difference signal before and after damage.

Abstract: This paper presents a set of novel profiled strip parameter measurement equipment which is in serial production. In order to measure shape parameter, this paper designs the structure of equipment and illustrates method of image processing which carries on object location and shape parameter calculating work-piece for using machine vision. This method is proved to be useful and efficient in practice. This paper is innovative in four facts. First, it works using image processing which never appeared in such type of application. Similarly, the equipment can work no matter what directions that profiled strip lies. Third, the equipment can work automotive without man-made measurement error. Finally, it can be used to measure multi-kind of work-piece in the line. This method can be widely used in other similar application.

Abstract: This paper mainly deals with the problem of oil pipeline leak and difficult to detect its location, combining the trait of our country’s oil pipeline, researching the leak detection and location based on the PVDF piezoelectric sensors. This paper firstly describes the domestic status of pipeline leak detection, and then gives a brief introduction for the PVDF piezoelectric film, finally discusses the pipeline leak detection and location system based on PVDF piezoelectric sensors. Experiments show that the use of PVDF piezoelectric sensors on pipeline leak detection, the leak can be correctly identified, and improving the detection sensitivity and leak resolution, effectively reducing the false alarm rate.

Abstract: The gauge detection between high signal and contact net is an important part in railway safety production. According to the detection nature, this paper designed a visual detection system to solve the problem of gauge detection between high signal and contact net. Using template matching method to break up the gray target image, and using discovering turning point method to rebuild target in space. Then according to the principle, it prepared detection system based on VC++2008 and OpenCV. The experiment results showed that: measurement error was within士15mm, when detection distance was arrange from 45.0m to 55.0m. Detection system which had high accuracy and good reliability, met system design requirements.

Abstract: Turbine flow meter is a very significant measuring instrument. As an important flow meter, turbine meter is widely used in many fields for its high accuracy, good repeatability, small size and light weight. However, with the viscosity of the measurement fluid increasing, the measured variation of the linearity becomes bad, which makes great influence on the meter factor. In this paper, the experiment on the viscosity impact of turbine flowmeter's performance was completed by adjusting the temperature of the mixture of diesel and lubricants, i.e. changing medium viscosity. And the methods of computational fluid dynamics (CFD) numerical simulate were used to research the accuracy of the turbine flow meter in the same conditions. According to the comparison of the two methods, the influence of the turbine flowmeter’s precision measuring fluids with different viscosities was analyzed. It provides a data basement for improving the measurement accuracy of a certain viscosity fluid in the future.

Abstract: Laser displacement sensor(LDS) displacement measurement is a non-contact measurement with more precision and a wide range of applications.。In this paper, a laser accurate displacement measurement system based on LDS and three-dimensional linear-servomotor-driven actuators (3D LSDA) is presented. The 3D LSDA moving system is composed of linear servo motor, precision movable liner mechanism and servo machine. It is driven to move the noncontact laser displacement sensor to scan surfaces through the three-dimensional electric displacement platform, and then the measurement data is processed. The displacement sensor resolution is 2μm; each dimensional electric displacement platform repeated positioning accuracy is higher than 5μm.

Abstract: The objective of this study is to develop a real-time strategy that results in higher precision than any real-time solutions currently available for GPS satellite clock monitoring. A real-time time transfer methodology was employed for satellite clock monitoring, composed of carrier phase smoothed code measurements and IGS ultra-rapid products to obtain precise satellite positions. The performance of the time transfer method was assessed by comparison with the results based on the all-in-view method using the broadcasting ephemeredes. The results showed that the stability of satellite clock monitoring for a short-term period was improved by the proposed method.