Applied Mechanics and Materials Vols. 241-244

Abstract: Using coordinate measuring machine(CMM) PMM12106 to measure the standard template, various factors will affect the accuracy of its calibration results. Based on system analysis of the various factors in the calibration process, application of test data, the paper proposed a new calibration method considering the key factors, like measuring rod deflection, probe diameter, and temperature and so on, evaluated the uncertainty in measurement, then programs. Compared to NIM data, it concludes that the measurement data is accurate, reliable, and suitable for the calibration of the standard template whatever it is API standard template or Premium-thread standard template.

Abstract: Fabric defect detection and classification plays a very import role in automatic inspection for textile. With the use of wavelet transformation and gray-level co-occurrence matrix to extract feature value of nonwoven image, then grey relational analysis of grey theory is availed to conduct the classification of uniformity of nonwoven. Of these processes, they care carried out mainly to discover uneven images for nonwoven, and proceed with classification study. Grey relation analysis can be used to find out the relation with selection feature indicators upon each factor to be studied and analyzed through some images processing through random factor sequence, and the highest relation is followed to determine the uneven images for nonwoven.

Abstract: Video surveillance technology plays an important role in the security field, with its intuitive, convenient and abundant information and is widely used in city traffic, civil security and other various fields especially in the important safety departments or major events. In this paper, according to the video surveillance system features and functional requirements, we use embedded system ,OMAP4460 and Android operating system on the basis of the panoramic technology to realize vertical 180 degrees horizontal 360-degree panoramic video surveillance. In the paper we profoundly analyze and discuss the embedded panoramic video surveillance system mainly from the hardware platform structures, the design of the peripheral circuit and the panorama function implement.

Abstract: PBS is an important optical part of the heterodyne interferometer which separates the two orthogonal beams with the different frequencies from an incident mixed beam. The relations between the nonlinearity errors and the PBS in the heterodyne interferometer are studied in the paper. From the theoretical analysis, the nonlinearity errors don’t caused by the imperfect PBS with the nonideal transmission or the nonideal reflection, while the nonlinearity errors exists in the imperfect PBS with the nonideal transmission and the nonideal reflection. It’s a useful conclusion in the optical design of heterodyne interferometer.

Abstract: The biggest challenge of visual navigation localization is feature extraction and association. Currently, the most widely used method is simple corner feature and simple matching strategy based on SAD or NCC. Another option is scale invariant feature and rotation invariant descriptor, typically as SIFT, SURF. Feature extraction and matching methods based on the SIFT or SURF are accurate and robust. However, its computational complexity is too high and not suitable for the real-time navigation localization task. This paper presents a new fast, accurate, robust stereo vision navigation localization method, based on a new developed ORB feature and descriptor. First, we presented our matching method based on ORB. Then, we obtained matching inliers and an initial motion estimation parameters using RANSAC and three points motion estimation method. Finally, nonlinear motion refinement method was used to polish the solution. Experimental results show that our method is robust, accurate and real-time.

Abstract: A wood color grading method based on the characteristics of wood images and support vector machine(SVM). A high-performance color charge-coupled device camera captures color from wood samples and transmits images to the computer, then Hue from Munsell color system (HSI) and color vector angle (CVA) are used to characterize wood color of samples for the comparative purpose.These eigenvalues build two training sets,using support vector machine to establish the color classifiers,and test each classifier.The experimental results show that, the classification method based on the CVA and support vector machine can quickly and accurately estimate the level of the color of the wood materials, improve the level of automation and production efficiency in the wood processing.

Abstract: With the rapid development of quantum manipulation technique, atomic spin gyroscope has been demonstrated in recent years. Understanding the sources and the influence of error on the performance of atomic spin gyroscope is important during the design of such devices. The basic principle of atomic spin gyroscope was reviewed and the analysis of error sources presented began with the coupled Bloch equations describing the dynamics of atomic spin gyroscope including magnetic field, light shift and pump-probe non-orthogonality. It was shown analytically that the first order effects of the transverse magnetic fields and imperfections can be eliminated by turning the longitudinal magnetic field on the magnetic field compensation point. The effects of longitudinal magnetic field and light shift imperfections with other terms zeroed contributed only to scale factor of the atomic spin gyroscope. Furthermore, the effects magneto-optical crystal and magnetic shielding due to temperature drift were described and according approaches to suppress these errors were also proposed.

Abstract: The articulated arm coordinate measuring machine (AACMM) is a new type coordinate measuring machine (CMM) base on the linkage structure with the characteristics of small size, light weight, large measurement range and flexible movement. The kinematic modeling methods of six degree of freedom (6-DOF) AACMMs are studied in this paper. By analyzing the structural characteristics of AACMMs the kinematic model of a 6-DOF AACMM with DH method was established. From the kinematic model the coordinate systems and structural parameters of the AACMM are obtained. Then the homogeneous transformation matrixes from the probe to the base of the AACMM are derived. Finally, methods of numerical computing and graphical simulation are used in verifying the kinematic model. The kinematic model provides a basis for measurement, calibration and error compensation of the AACMM.

Abstract: To improve the effectiveness of pedestrian tracking, the histograms of oriented gradients (HOG) and color histogram characteristics are adopted to track pedestrian based on particle filter. Firstly, the pedestrian is detected using the HOG features to determine the initial target position. Then the target is tracked based on particle filter utilizing color histogram, during which the HOG is used to modify particle heavy weights and particle sampling. Experimental results verify the accurateness and efficiency of the proposed method.

Abstract: Interharmonic adjoining harmonic or fundamental wave can cause voltage flicker directly. It is of great significance to accurately detect the interharmonic composition for improving the quality of power. According to the frequency and broadband characteristics of real power grid signal, an improved interharmonic detection algorithm based on Lagrange interpolation and ZoomFFT is proposed. The amount of data with ZoomFFT method is less than with FFT operation directly, so the time for detecting interharmonic can be reduced. According to estimated frequency with Lagrange interpolation, the ZoomFFT method calculates its amplitude and initial angle related to every son signal. Matlab simulation results show that the solutions are more accurate with reasonable computational time.