Papers by Keyword: Optimization

Abstract: This paper presents the optimization of gripping points of an end effector of three fingers, and this is done by ensuring that the force exerted on the object is minimum. It begins with the design of the gripper has two degrees of freedom (DOF) for each finger. Is performed a brief mathematical description of the kinematics involved in the gripper and with this is determined the work area. With the workspace is determines the points with contact with the object geometry are obtained and these are gripping the possible points of the object. To select which of these points is the best to grab the object, we proceed to evaluate the force exerted on the object by means of the mathematic denominated of Screw. This force should be minimal, avoiding sliding and in turn damage the object. As the contact points are numerous and the evaluating would take quite some time in an algorithm combinational by this reason the optimization algorithm Non-dominated Sorting Genetic Algorithm (NSGA) is implemented.

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This paper introduces the structure and working principle of biomass fuel hot stove, and analyses the existing problems in the combustion process. Simultaneously, the paper proposes the optimization about the wall high temperature of the hot stove, which is the main issue in the hot stove.

Biomass resources in China is very abundant.only the amount of resources of agricultural wastes (such as straw) each year is equivalent to 3.08 tons of standard coal. The biomass briquette is compressed with loose, amorphous materials, such as straw, rice husk, sawdust, wood chips, into a shaped, denser solid fuel with the method of mechanical pressure. It has the advantages of small size, high density, easy storage and transportation, combustion stability, long cycle, high combustion efficiency, low contaminant levels in ash and flue gas. It provides an effective way to solve the energy shortage in rural areas and straw burning problem fundamentally[1].

Abstract: Producing good surface integrity is one of the main challenges of the machining industry. The increase of the utilization of minimum quantity lubrication (MQL) in order to reduce the amount of lubrication induced a lack of understanding of the physics behind the residual stress generation. Residual stress in the machined surface and subsurface is affected by materials, machining conditions, and tool geometry. These residual stresses could affect the service qualify and component life significantly. Residual stress can be determined by empirical or numerical experiments for selected configurations, even if both are expensive procedures. This paper presents a hybrid neural network that is trained using Simulated Annealing (SA) and Levenberg-Marquardt Algorithm (LM) in order to predict the values of residual stresses in cutting and radial direction after the MQL face turning process accurately. First, SA is used to train the weight and bias values of the ANN after which LM is used to fine tune the values trained by SA. Then, based on the predictions, an optimization procedure, using Genetic Algorithm (GA), is applied in order to find the best cutting conditions. At each generation, GA suggests a population of inputs that are then sent to the trained ANN in order to predict the residual stresses. The objective is to find the optimal inputs that minimize the tensile stress on the machined surface.

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Free-form and bionic spatial shells are popular in the area of spatial structures. Scallop-shaped surface is the product of evolution and a kind of spatial shells that can satisfy the mechanical requirements. Based on the scallop-shaped lattice shells, this paper focused on the optimization of geometric parameters. The principle of minimum strain energy was applied to conclude the influence law of the geometric parameters on mechanical properties. Finally the optimal values of geometric parameters were obtained. The results show that the optimization of geometric parameters presents the integrated significance to improve scallop-shaped lattice shells.

Abstract: Wireless resource management is one of the key techniques in cognitive radio networks, which attracts great research attention, international cooperation project and other fundings. The dissertation contains valuable work on both theories and applications.A novel method using bipartite graph matching is proposed to realize the dynamic spectrum access. An idealized method and an operative method are presented respectively based on the famous Kuhn-Munkre algorithm. Experimental results show that proposed algorithms dramatically maximize the spectrum utilization and reduce allocation conflictions among users.

Abstract: Analysis of the features of Mastercam, Solidworks and Vericut software and their respective advantages, Proposed by Solidworks, MastercamX and VERICUT three software are combined as the optimization platform to build the NC machining program integrated modeling, assembly, processing, simulation and Optimization in one. Author take rub a drum processing for an example, in the Solidworks modeling, assembly, in the Mastercam X programming and generate the NC program, through VERICUT for the simulation and optimization of NC program, Examples show the rationality of optimization, avoiding the collision, the production and processing of the interference, the over cut phenomenon, Three software effectively combined, play a very high efficiency, improve the using efficiency of NC machine tool, has the certain reference significance to the actual production.

Abstract: The Chaboche unified model with kinematic recovery term was used to describe the cyclic plasticity and viscoplasticity of a new nickel-based superlloy. The model response sensitivities to the change of each parameter of this Chaboche model under either stress control or strain control are calculated and analysed. Influential parameters were identified. This has facilitated the design of an efficient test matrix and the development of a gradient-driven non-linear optimisation algorithm.

Abstract: Setting up a model for the structural finite element, there are inevitably differences between the model and the real bridge .To make the model accurate it is necessary to update the model by using static performance results. In this paper, the optimization function of ANSYS is used to update the real bridge’s model. The final updated finite element model for the real beam is able to produce natural frequencies closer to the real ones .The updated is useful for the reference model to structure damage and condition assessment.

Abstract: According to the structure feature of HTS magnet, heat transfer process in steady-state conditions is analyzed, and the heat conduction model of magnet unit was established. The thermal structure of conduction cooling HTS magnet was optimized to minimize the maximum temperature difference of magnet unit, and the optimization result was verified with simulation method. Simulation results show the optimization method mentioned in this paper is effective, which can provide a guidance to heat transfer structure design.

Abstract: Processes of electrolytic application of metals are used in order to obtain pure coatings, single - or multilayer. Appropriate selection and proper execution contribute to the improvement of product quality, which affects its proper and long functioning. Production costs are not necessarily high. They depend mainly on the proper selection of the coating. The article presents the results of the use of generalized objective function for selection of galvanic coating on metal parts. There were used following criteria in order to characterize the quality (usability): corrosion resistance, mechanical properties, physical properties, gloss, roughness, and economical criteria. Presented method of determining the objective function can be used to choose the optimal coatings for specific service conditions or customer requirements. Presented method of determining the objective function in the design process of the surface layer makes it possible to assess the impact of various factors on the quality of the product and thus gives a chance to make the right choice.