Applied Mechanics and Materials Vols. 347-350

Abstract: In this paper, an Improved Ant Colony Algorithm is applied to the identification of the ship motion modelNomotos 1st-order nonlinear model. A robust method based on Ant Colony Algorithm is proposed for the optimization of the continuous function. The transfer criterion of the ants between each layer and global pheromone updating process are described. Some experiments results show that this method has good identification accuracy. The algorithm is feasible and effective, is of enormous significance to the system identification of ship motion.

Abstract: Aiming to the advantages of traditional manual mechanical adjustment for gaps between key parts of offset machine, a method for gaps adjusting automatically was proposed and a prototype of adjusting device based on BR622 offset machine was formed. In this research, the principle of adjustment automatically was discussed, the configuration with the ARM controller as core of adjustment automatically system was designed, the control software process was analyzing and a prototype was developed. Finally, a method based on gray model is used to predict the trend of offset machine. The method of automatic adjustment for gap can simplify the operations and has practical significance.

Abstract: This paper takes UGNX6.0 as the development platform, by using its UG/KF development tools, fusing feature and knowledge together, so as to realize the process associated with the geometric design knowledge and stamping process design. Based on the features of stamping process, the classification of stamping process knowledge has been studied. With the object-oriented method, the rule-based and instance-based technology for expressing and acquiring the stamping process knowledge is discussed. Based on this, the stamping process model driven by knowledge has been established. It showed the importance of the CAD technology in designing of relatively complex progressive dies. Based on the knowledge engineering process designed, the degree of intelligence stampings process design has been enhanced, design quality and efficiency has been improved, and the dependence of the process design experience of designers has been reduced.

Abstract: The muzzle flow field of powder gas shock wave was simulated by the fluid software Fluent and 7.62mm rifle was taken as the example. The generation and evolvement of the flow field of powder gas shock wave were studied, the pressure contour map of 7.62mm rifle muzzle flow field was obtained. By comparing the calculated results is drawn a conclusion that the projectile and the initial flow field have a significant influence on the genereation and development process of the muzzle flow field.

Abstract: Compared with the traditional method of contact collection, contactless acquisition is the mainstream and trend of palm vein recognition. However, this method may lead to image deformation caused by no parallel of the palm plane and the sensor plane. In order to improve the limited effect of Scale Invariant Feature Transform (SIFT) about this problem, a better method of palm vein recognition which based on principle line SIFT is proposed. Based on the self-built database, this method is compared with the SIFT and other typical palm vein recognition methods, the experimental results show that our system can achieve the best performance.

Abstract: Cold-background multitarget compounding system provides infrared targets for hardware-in-the-loop simulation system, in which large aperture reflective mirrors are employed. In this paper, we proposed a combined belt-back structure and designed the flexible connection to solve support mechanism of large aperture mirrors for 100K temperature variations. By Finite Element Method analysis, root mean square (RMS) of optimized mirror was better than λ/40 under self-gravity and 100K temperature variations. By Zernike polynomial fitting, MTF of multitarget compounding system was over 0.5 and RMS spot diameter was less than 0.05mrad. Results demonstrated that the proposed support mechanism was effective and provided analytical data for 1m level mirror in large environment temperature variations.

Abstract: Maximum likelihood (ML) detection algorithm for multiple input multiple output (MIMO) systems provided the best bit error rate (BER) performance with heavy calculating complexity. The use of QR decomposition with M-algorithm (QRD-M) had been proposed to provide near-ML detection performance and lower calculating complexity. However, its complexity still grew exponentially with increasing dimension of the transmitted signal. To reduce the problem, an improved detection scheme was proposed here. After constructing the tree detecting model of MIMO systems, the ML search of one layer was done, the branch metrics were calculated and sorted, which gave an ordered set of the layer, then depth-first search were used to search the left layers with termination methods. The proposed algorithm provides near QRD-M detection performance.

Abstract: To be faced with the appearance and mechanical defects during refrigerator door making process, enterprises have no effective solutions. A springback prediction system is developed to accurately predict the springback of sheet metal and to improve die design. The main components, key theory and technique of this system are illustrated for the purpose of revealing co-relationship of springback and constitutive model and different parameters. It provides a powerful tool for cutting production cost and raising working efficiency. It is of great significence for engineers and enterprises.

Abstract: Aiming at the triangular mesh holes generated from incomplete data in reverse engineering, a novel algorithm on island filling was proposed. The focal point of this work was automatic recognition and repairing algorithm on island holes. The island holes are recognized based on the projection on characteristic plan. Then, by connecting island holes and outside holes of the island, island holes are converted into the ordinary holes to repair. Experiment result shown that the proposed method is efficient and stable in island hole filling.

Abstract: Texture recognition plays an important role in machine vision and signal processing. Over the last three decades, many texture analysis and recognition methods have been proposed, but most of them are sensitive to geometric distortion. This paper presents a new approach to scaling and rotation invariant texture classification using invariant moments based on radon transform. The radon transform is utilized to project the texture image onto projection space. Then the geometric invariant moments are calculated by the projection data. The support vector machine-based classifier is employed to implement the texture classification. Experimental results show the high classification accuracy of this approach.