Advanced Materials Research Vols. 655-657

Abstract: To solve acquired the membership degree in fuzzy evaluation. we use correlation function in extension theory to calculate the degree of association between evaluation indicators and fuzzy scales, and then the degree of association is done standers conversion and normalized processing,, getting the membership value of evaluation matrix in fuzzy comprehensive evaluation. Comprising traditional statistical methods and expert evaluation method, the membership value of evaluation matrix which is gat through correlation function method of extension theory is more simple and reasonable. Comprehensive evaluation value is got from Calculating linear weighted between evaluation matrix and the index weight coming from analytic hierarchy process. Finally, using two type of home made NC machine tools as example to do the practical application study of the proposed method, the results show that this method can give the reasonable evaluation.

Abstract: The thermal error of main-shaft is the main factor that effects the machining quality and efficiency of NC machine. The modeling of thermal error of the main-shaft is significant. There are a lot of methods to build the model. The method of least squares support vector machine has good effect on non-linear system and make the model have good decision-making ability. In this paper, the temperature field of the main-shaft is sampled and the important parameter and is optimized in a wider range when modeling with the least squares support vector machine by using grid searching method on the Matlab platform. In this way, the modeling accuracy is improved effectively.

Abstract: In order to further improve the accuracy of the trajectory control and reduce the contour error, a novel method is proposed. This method uses a slight arc segment to approximate the trace curve between discrete points based on the acceleration information. The acceleration information of every discrete point will be provided to the servo control system of each axis to execute the acceleration feed forward control, thus realize the arc connection between the interpolation points. Finally, the simulation experiment results verify the effectiveness of the proposed algorithm.

Abstract: Bootstrap Method is commonly used in statistical inference and is convenient and practical in data processing. The paper puts forward an improved Bootstrap method which expands the range of resampling procedure to verify the maintenance indicators with a few test samples.

Abstract: Currently, the ancient calligraphy and painting are widely used in decoration screen; however, the processing technic is normally based on manual manipulation. Normally, this kind of processing is not efficient, and with highly cost. In addition, it could not maintain the original artistic style in maximum. the paper proposes to process the sculpture of ancient calligraphy according to its photo, by adopting the CNC technology based on reverse engineering method, which enables to mostly keep the original artistic style, and to create the CNC code automatically with the assistant of image processing to achieve intelligent machining.

Abstract: Advancing the machining accuracy of machine tool is one of aim of numerical control machine improving . There are many effecting machining accuracy factors of economical numerical control machine tool driven by a stepper motor . The way of improving machining accuracy and compensation method were put forward in this paper .

Abstract: For the aim of disassembly and recycle the End-of-life Vehicle (ELV) efficiently and rationally, the scheme of flexible dismantling cell is presented. Especially, how to cut off the windshield of ELV automatically is a key technology among them. The contour of the windshield is detected by a special sensor. And then all the data points will be processed according to the curvature, after that, NURBS based method is used to fitting the contour of the windshield.

Abstract: The existing building metallic prototypes from metal sheets or foil slices methods suffer some limitations, such as difficulty in making complex features and long process cycle time. The Fully Dense Freeform Fabrication (FDFF) process is a new freeform fabrication method capable of building fully dense prototypes from practically any materials in a layer-by-layer basis, which overcomes the limitations of other methods. However, layer aligning and stacking are still very challenging because aligning and stacking all thin layers takes a lot of time and effort. Therefore, an automated layer aligning and stacking system is proposed and implemented in this paper. A vision system together with a robotics system are developed to automate the FDFF process. Experiments were performed and the results demonstrate that the automated FDFF process can fundamentally improve the concept of rapid prototyping by enabling producing fully dense parts with any complexity and any solid materials for the sizes from micro scale to several feet in a very fast and low cost approach.

Abstract: Designed a method based on the complexity of multiple nested parts to extract and analyze the information of parts. In order to simplify the algorithm and improve the efficiency of the program, a data structure stored all information of entities was presented. The theory of the region method was introduced in this paper, and a specific algorithm was designed to judge the nested relationship between contours by using this theory and entities information. Finally, the computational result can be used to determine the contour cutting order.

Abstract: Adjustable form cubic interpolation spline curve, changing its form adjustment coefficient can adjust the curvature radius and shape. Using this spline curve can realize the high-speed smooth connecting between adjacent processing trajectory during NC movement. To internal outline corner transition, use cambered spline transfer curve; To external outline corner transition, can use cambered or toroidal spline transfer curve. During the corner transition process, keep the speed constant, adjust the curvature the curvature radius to control the value of acceleration. Corner smooth transition based on the interpolation spline, can effectively reduce the mutation of acceleration, improve processing efficiency, and weaken the impact to the machine tool.