Key Engineering Materials Vols. 467-469

Abstract: According to the connotation of Scientific Outlook on Development, this paper constructs an enterprises scientific development performance evaluation model based on factor analysis and combination weighting. The innovation points and contributions are in three aspects. First, by evaluating performance from the manpower criterion, the basic idea of Scientific Outlook on Development of people-oriented is reflected. Second, by applying the factor analysis to screen evaluation indicators, fourteen indicators are selected to reflect more than 85% of original information and avoids information duplication and redundancy. Third, by determining the combination weight through multiplicative synthesis method based on G1 and TOPSIS, it fully utilizes experts’ subjective experiences and objective information.

Abstract: The Walking Assistant Robots(WARs) developed by our institute are introduced in this paper. First, three prototypes with different mechanical and control structures are introduced and compared. Then as for the prototypes Ⅲ, its main framework and three important function modules including force sensor based human-machine interaction, Omni-directional vision based tracking and guiding system, and web-based monitoring system are described in detail. The WAR can recognize the user’s intents and execute different assistant functions, such as seating or standing-up assistant, walking assistant, human tracking, location, obstacle detection and avoidance. The application in an elderly care center shows WAR has a perfect and stable performance.

Abstract: A fuzzy-PID temperature controller with excellent Man-machine interface was developed employing fuzzy-PID control theory combined with uC/OS-II embedded system based on S3 C2440, ARM9 kernel produced by the Samsung Company. The development is aim at improving overshoot and regulation delay in the existing temperature acquisition and control system. Reducing of regulation time and improvement of precision was achieved by using fuzzy-PID control without any accurate mathematical model. While shorten time and improve efficiency of development were achieved by transplantation of the uC/OS-II operating system.

Abstract: This paper introduces the characteristics and requirements of speech recognition technology based on embedded platform. It also describes the basic theory and related properties of Support Vector Machine. The advantages and disadvantages of the Multiclass SVM algorithms are analyzed, providing the algorithms principles for training and recognition of SVM application in the embedded speech recognition system. Finally, we proposed a design strategy based on multiclass SVM decision tree classifier, combined with the features of the embedded speech recognition.

Abstract: Methyl Cellulose (MC) is a kind of water-solubility and non-ionic cellulose ethers, which has been used widely. Currently, the small bulk density and the slowly dissolving velocity are the main deficiencies of Methyl Cellulose. These two deficiencies of Methyl Cellulose can not meet the need of efficient working. The way of improving the fluidity and dissolution deficiency may be to increase bulk density and granulation. Current granulation method of Methyl Cellulose is logical but with low efficiency and high cost .So, it is necessary to develop a new technology to produce Methyl Cellulose grain with high bulk density and good dissolution. Based on the theoretical analysis, we develop a new manufacturing technique using co-rotating twin-screw extrude as a main device,together with other auxiliary equipments according to reasonable technical process. Through measuring the bulk specific weight of Methyl Cellulose, its solubility and luminousness in water, the optimum of the experiment is estimated .The preferable optimum condition parameters of increasing bulk density and granulation are that moisture content is 40-60 percent, temperature is 30-50°C, with intense mixing and extruding. Through increasing granulation, the bulk density is as twice as that of before, at the same time, the dissolution improves remarkably.

Abstract: In view of the poor anti-noise performance of traditional methods, the principle of camera calibration is analyzed based on calibration template with planar circles, and a new calibration technique is proposed based on pin-hole perspective model. Firstly, the edges of image ellipses are located in sub-pixel by spatial-moment operator. Then elliptic equations are obtained by the Least Square Fitting method, and common tangents of two arbitrary ellipses are also calculated. Finally, the extrinsic and intrinsic parameters are computed by the Radial Alignment Constraint (RAC) model. Experiments results indicate that proposed method has a goof performance of lower computation complexity and higher precision.

Abstract: Crankshaft is one of the main components in reciprocating mud pump (RMP). Its stress significantly affects reliability and performance of high pressure and large power RMP. In this study CAE stress analysis was actively applied to secure the high reliability of main components and improve the performance of RMP. Through movement analysis and computation for various components of RMP, the load of crankshaft was obtained. By effectively using CAE stress analysis to three kinds of dangerous working conditions of crankshaft, distribution characteristics of the max main stress, the min. main stress and the Mises stress were obtained. The most dangerous condition and position were gotten through stress analysis. The analysis results give theory support for design and development of high pressure, large power, high performance and high reliability RMP.

Abstract: CAD/CAM/CAE (3C) was effectively applied to twin-spirals scroll compressor (TSSC) from conceptual design to finished products in this paper. A virtual model and mathematical model of TSSC was developed. The swarm intelligence algorithm was used for TSSC optimization and the final optimization design variables were gotten. CAE was used to study the two key components of TSSC-orbiting and fixed scroll, which is useful for improving the quality and reliability of manufacturing and assembly accuracy at the later stages. CAD, CAPP, CAM, CAE and NC tool path code generation are included in 3C. The prototype of TSSC was manufactured based on 3C. The used results indicate that 3C method can well overcome the blindness and limitation of the traditional design. It offers the new method and idea for wide application of the scroll compressor.

Abstract: Through analysis of Traditional CAD software modeling methods, combined with process planning requirements of intelligent virtual assembly, in the proposed semantic-based multi-level top-down model of virtual assembly. This paper proposes a semantic-based top-down model of multi-level virtual assembly.On this basis, the assembly semantic information extraction process is Focused analyzed, in the three-dimensional model data, non-geometric factors such as assorted features, assembly features, assembly engineering relations are extracted, and modeling is Established by Protégé ontology-based tool, the model is imported into the 3DVAPP(3D Virtual Assembly Process Planning) system to be verified, and Finally this paper implementated the assembly process planning applications such as intelligent parts identification, Provide a theoretical and practical basis for intelligent virtual assembly.

Abstract: FMM is an efficient algorithm in computing N-body problem. This paper firstly partitions the FMM into 8 procedures. Based on the analysis the running time and computing type of each procedure, we choose key procedures accelerated on FPGA, and then we present the speedup ratio of each accelerated procedure through experiments. According to the FPGA acceleration effect on the procedures, a multi-level acceleration project is proposed. Finally we put forward a hardware architecture of FPGA accelerated high performance computer.