Papers by Keyword: Complex Surface

Abstract: Introduced reverse engineering technology and working principle. Researched reverse design process of the complex curved surface "spider". The data were collected by means of multiple scanning measuring with laser scanner. Used Geomagic Studio software for date point cloud processed of complex curved surface. Used UG software for surface reconstruction designed. Product reduction and improvement of the design were finished rapidly and high quality. Model of spider was printed with rapid prototyping technology. Compared with physical, the model’s reliability and accuracy were verified by reverse engineering design.Keywords: complex surface; reverse engineering technology; UG; Geomagic Studio software

Abstract: This paper presents a new strategy of analysis and compensation of non-linear error. Non-linear error is an important source of machining error in multi-axis numerical controlled machining and it is unavoidable. In view of tool positions optimization in five-axis CNC machining of complex surface, this paper presents a strategy for non-linear error compensation in five-axis machining: Firstly, non-linear error caused by the change of tool axis vector is analyzed and the non-linear error model is established, in order to get the maximum non-linear error of interpolation segment; Then, the tool position that meets the machining accuracy is obtained; Finally, Simulation and analysis of the model show that the proposed method is effective and greatly improves the geometric accuracy.

Abstract: The development of modern advanced manufacturing technology greatly relies on the CAD / CAM technology. Many pieces of computer software with CAD/CAM function have been developed rapidly in recent years. Unigraphics (UG) is one of the outstanding representatives. It has a powerful design and CNC programming function, and CAD/CAM seamless connectivity. As an application example, a mouse model part which has complex surface was designed and trial-manufactured with CNC machine. First, the 3D model of the part was created in the modeling module of UG software. Then, the process scheme was developed after analyzing. In the manufacturing module of UG software, the NC machining parameters were set according to the processing requirements, the tool paths were generated, edited and checked, and the NC codes were generated by post processing. And then, the NC machining was simulated in YULONG software. Finally, the part was manufactured in a 3-axis CNC milling machine. It has desirable shape and high accuracy. The results show that UG has a perfect CAD/CAM function. The CAD/CAM technology based on UG makes the NC machining of complex surface part very convenient. It improves the efficiency of design and machining, shortens the manufacturing cycle, and reduces the cost, which reflects the importance of the CAD/CAM software in NC machining. The method described in this paper can provide valuable reference for processing similar parts, and it is also useful for related study.

Abstract: In order to enhance machining precision of complex surfaces with a flat-end cutter, the generating method of cutter contacting (CC) paths is presented in this article. With the method of coordinate transformation, effective machining radius of a flat-end cutter had been deduced and the step-over formed by two adjacent CC paths were implemented. The parameter increment along the CC path interval direction was calculated by using geometric analysis of the local area of CC point. The corresponding NURBS path of tool center points including knot vector and controlling points was obtained from the cutter contacting points.

Abstract: In general, when using the three-dimensional measuring machine to test a workpiece, the measuring route should to be planned firstly. Regarding workpieces which are formed by elementary curve or surface, there are specific software installed in the Coordinate Measuring Machine which can be used to generate the measuring route. However, when there are workpieces with no mathematic model, measuring process usually has to be done by manual operation. In this paper, we concentrate on the technical problem of measuring the blade with complex surface. After analyzing the geometric characteristics of blade, we did research on the self-study function of the Coordinate Measuring Machine, and finally put forward a method to rewrite the self-study measuring program according to geometric characteristics, which will successfully realize the automatic measurement of complex curved surface.

Abstract: Based on triangulation plane parametric method, the in-depth research of the complex surface flattening system has been attempted. The required database system of complex surface flattening algorithm is established. An attached LSCM algorithm is realized. To be continued, with a proposed initial parametric network, the auxiliary program is constructed with higher accuracy. A friendly interface in VB was finished and a complex surface flattening system is realized with Solidworks secondary development technology based on SolidworksAPI interfacing.

Abstract: Key parts of pump produces belong to the thin-walled parts.And cutting parameters have a direct influence on the processing accuracy of impeller. To solve this problem, it is necessary to found the simulation model of tool and workpiece based on advanced metal cutting simulation software named Advant Edge FEM. And stress load should be loaded, using single factor analysis method to study the law of influence and its causes of the milling cutting parameters on pump thin-walled parts cutting force. And the gotten results can provide reference for the design and manufacture of pump thin-walled parts.

Abstract: Different error requirements on different surfaces are necessary in many situations. If the registration between the measured dataset and the nominal surface is performed ignoring these differences, an inaccurate result could occur due to the surfaces which have low precision. An improper registration even results in false verdict. So the differentiated registration is of significance in precision engineering. In this paper, a new registration method taking into consideration of the different error requirements is proposed. Firstly surfaces are classified based on different error requirement. Then, appropriate weight factors are iteratively given to these surfaces. Based on the change relationship of error and weight factors, the algorithm controls the error distribution by optimizing the weighted least squares. Our method has the great flexibility in distributing the error, which is suitable for engineering applications. The experiment demonstrates the validity.

Abstract: Disappearing mould casting is a new accurately processes with nearly free margin and precision forming, in which is no modulus, no parting, no sand core, so the casting without splash, burr and taper angle. It can improve the dimensional accuracy of the core portfolio for complex surface of the key compose of the disappearing mould. It has completed the design and manufacturing of these by the three-dimensional CAD/CAM technology, and obtains a series of effective methods and experience for the development of the products. The researched results have important directive to production practices for the design and machining process for the expendable pattern casting.

Abstract: Studying how to distribute the sampling points on processing surface has important practical significance on improving the detection quality and efficiency. So, this paper introduced Bayesian networks to the research of sampling points reasonable distribution, carried out Bayesian networks classifier learning of four typical sampling methods and the result obtained through analysis experimental and simulation data verify the feasibility of this method.