Applied Mechanics and Materials Vols. 397-400

Abstract: Optimal control of the boiler combustion system is related to the economy and stability of the entire production process. To the problem that the boiler main product steam quality and the safe operation of the boiler optimization control, the fuzzy adaptive algorithm combined with the traditional PID control in the DCS system is proposed. The method optimizes the control system parameters and improves the control program. The simulation results show that the control scheme is better than the traditional PID control, and has good dynamic performance and stability. Both the boiler outlet steam quality and the security operation of boiler are improved.

Abstract: To the demand for the discretization of STL(Stereolithography) model in sheet metal CNC incremental forming, two kinds of discretization algorithms respectively based on unequally divided projection grids and unequally cutting planes were proposed. And the software systems were implemented by using VC++6.0, C++, OpenGL. Meanwhile the comparison of every discrete model with the original test model was done by using RapidForm XOV verification software. The case study shows that both discretization algorithm can generate uniformly distributed discrete points, and compared with the original test model, the average errors are 0.0475 and 0.0036 respectively.

Abstract: This paper is concerned with the study on the assembly optimization of a hull section based on the genetic algorithms. It is significant important for improving efficiency of shipbuilding. Firstly, a typical hull section is selected as the analysis target for the assembly optimization. Then, the period and cost of shipbuilding is combined with the genetic algorithms, in which, the optimal assembly sequence is very important for the analysis, and it should be drown up. Finally, the hull section model is constructed by using CATIA software, and the simulation demo of the assembly procedure is carried out. The Genetic algorithm is a global optimizing method which can improve the calculation speed by using the subassembly. The virtual assembly of hull section based on the genetic algorithm is carried out under the environment of CATIA software, which including entity design, assembling and post-processing analysis and so on. The virtual assembly technology can be widely combined with the engineering production, not only have a significant effect on reducing costs and shortening the period of production, but also improve the quality of production. It is very useful for providing valuable reference in the actual productions.

Abstract: Drying is one of the important chain of operations in agricultural industry, having important implications for maintaining edible quality and reducing the production loss of grain. International and domestic scholars have done a great deal of research about heat and mass transfer, change of grain quality, process monitoring and equipment during the process of grain drying, but none about the risk analysis of grain quality during the process of drying have been published yet. Therefore, based on the model of change of grain quality that is previously built, the paper intends put forward some suggestions on the production and application of grain drying equipment, adopting the AFSOM method in the procedure of risk analysis of grain drying quality.

Abstract: Obtaining effective value points is one of key issues in cubic B-spline curve reconstruction. Since it is unfavorable for the selection of value points through curvature methods and the point cloud data acquired from ICT slice images is characterized with large volume of data, high noise and density, a baseline adaptive method is presented to get value points for curve reconstruction, baseline and scale threshold determined by wavelet multi-scale, in which the value points is obtained and curve is reconstructed automatically. Hausdorff distance is adopted to calculate the error of cubic B-spline curve reconstruction. Comparative analysis with existing methods proves that our method can effectively restrain noise and quickly reconstruct contour curves.

Abstract: Proposed application the reverse design in development design process of wine packaging container, treated the the key technical problems, reconstructed the CAD model of wine packaging container,and redesigned specific elements of wine packaging container based on current development trends and the main appeal points of wine packaging container design with the the CAD model to achive the final design scheme. The application example of reverse innovative design of wine packaging container is given.

Abstract: This paper addresses the problem of B-spline curve approximating to a set of dense and ordered points. We choose local curvature maximum points based on the curvature information. The points and the two end points are viewed as initial feature points, constructing a B-spline curve approximating to the feature points by the least-squares method, refining the feature points according to the shape information of the curve, and updating the curve. This process is repeated until the maximum error is less than the given error bound. The approach adaptively placed fewer knots at flat regions but more at complex regions. Under the same error bound, experimental results showed that our approach can reduce more control points than Parks approach,Piegls approach and Lis approach. The numbers of control points of the curve is equal to that of the feature points after refinement.

Abstract: Predictive current control algorithm which based on deadbeat theory is studied in this paper which can improve the current control performance of PMSM. In order to obtain high control effect, on-line access to accurate motor parameters such as fault diagnosis, condition monitoring is important in many areas, especially to improve the traditional deadbeat predictive current control algorithm sensitivity to inductance error, this paper presents an inductor-based parameter identification current predictive control algorithm of permanent magnet synchronous motor based on least mean square (LMS) theory. By Simulation the identified inductance will be feed back to the control model to improve the system tolerance of inductance error. A 0.75KW PMSM is involved to verify the performance of the proposed algorithm, then present and analyse the simulation and experiment results.

Abstract: In order to improve the precision of the short-term load prediction, a new method based on radial basis function (RBF) neural network is proposed. The weather data of samples includes the temperature, humidity, date, type, etc., and is quantified according the relevance to load, and then forecasting the power load using RBF neural network model in a region, Actual example shows that this method improves the convergence speed and prediction accuracy of load forecasting.

Abstract: In this paper, dynamic multicast routing and routing optimization criteria have been described.By comparing and analyzing the advantages and disadvantages of several non-rearranged dynamic multicast algorithms, the advantages of the non-rearranged dynamic multicast routing algorithm based on the delay constraint have been further confirmed and a conclusion has been drawn by performance testing.