Papers by Author: Fei Liu

Abstract: In view of the problem that it’s hard to determine the control points and morphing is not intuitionistic in traditional surface free-form deformation technology, an interactive surface free-form deformation method is proposed in this paper. Using this method, the user no longer needs to dynamically set constraint points outside the model. The point picked up by the user according to the desired deformation is used as a control point, and the neighborhood range of deformation or the deformation shape is controlled by deformation function. The designer can interactively deform the model simply by setting control parameters. The experiment results by applying the method to face modeling show that the proposed method is feasible and effective, providing a convenient way for the local modification of three-dimensional models.

Abstract: With a wide range of applications of free-form surfaces, the inspection of them is becoming critical, though it is difficult. A model inspection method for products with free-form surfaces is proposed in this paper, and the key process is described in detail including data import, data matching, and error comparison. The inspection results are not only displayed with color cloud map, but also the error values of the specific points can be displayed explicitly in the table. The experiment results by applying the method to a car lamp show that the proposed method is efficient and it can provide a reference to modifying the product for designer.

Abstract: The measurement of worker differences is fundamental consideration in personnel assignment which is one key decision that influences the productivity and quality of assembly production. Due to the weakness of presented researches on worker differences measurement, the concept of station fitness, which takes the worker skill level and accumulated execution time in a given period as parameters, is proposed to better describe the worker competency and provide a way of measuring the differences among workers. A personnel assignment optimization model based on station fitness for assembly production is constructed, and the objectives are maximizing the station fitness for each assembly station and minimizing the difference of station fitness for workers assigned in the same assembly line. Then a heuristic algorithm based on the fitness matrix is presented to solve this model. The results from the example demonstrate the feasibility of the approach.

Abstract: Information acquisition plays an important role on the production operation of modern job shop to achieve the goals of high efficiency, good quality, low cost, little resource consumption and low environmental impacts. This paper proposes the equipment integrated information acquisition system, the objective of which is to sense or collect the on-site information related with production operation in order to support managers’ decision-making or other application systems as basic data. The system architecture is constructed with five layer components. Furthermore, the two supporting technologies of the system are presented including the adapter definition in the adapter level and the establishment of template repository in the service level. Finally, the case study of the system is demonstrated by the application of acquiring production progress information in machining job shop.

Abstract: The real-time, the consistency and the accuracy of information transmission in cutting process are poor, and it is hard for manufacturing enterprises to enhance the machining efficiency and quality. Consequently, based on the real-time dynamic environment of cutting system and oriented to first-line production and operating workers, a networked optimal decision support system for cutting parameters was constructed; its system structure and function structure were described and its running mode was analyzed likewise. On the basis of research on the normative description of cutting process knowledge, an ontology-based description method of cutting process knowledge was proposed.

Abstract: Verisimilitude of 3D face modeling can be strongly enhanced by taking into account skin wrinkles. However, there are two difficulties to model real and natural wrinkles: one is the location of wrinkles and the other is the shape of wrinkles. For the first problem, an algorithm for locating wrinkles through extracting feature curves based on photo is presented; For the second problem, a shape control function is proposed considering the properties of real wrinkles, which could provides intuitive parameters for easily modulating the depth and the width of wrinkles, and express the attenuation and impact of one wrinkle on its surrounding surface. The experiment results by applying the method to a 3D face model show that it not only has the advantage of verisimilitude as the photo, but also has the feature of natural ripple which is deeper and wider in the middle than in both sides.

Abstract: The interest in environmentally conscious manufacturing has increased due to the goal of reducing environmental impacts and resource consumption in manufacturing system. However, little pays attention to the issue in the production operational process of manufacturing system. This paper introduces a new tool that integrates environmentally-conscious information into the job assignment activities. The objective of the tool is to assist production managers in their decision-making regarding resource-saving and environmentally-friendly assignment schemes. The system framework is built up with six components. Furthermore, the two key issues of the system are presented including the description of the information flow in the function level and the establishment of models in the model layer. The prototype of the system is developed and the demonstration is fulfilled in the gear machining shop floor.

Abstract: In allusion to the rapid design for building door and window products, a rapid design method based on generalized modularization was put forward. According to the combination of generalized modules, the product configuration model was automatically generated on the basis of generalized modular planning, and then the rapid design for building door and window products was realized by the instantiation of product configuration model. With the method, product designs and associated knowledge can be reused and the design cycle can be effectively shortened. A designing system for building door and window products was developed and applied in some enterprises, with satisfactory results.

Abstract: The function integration, process integration and information integration of the manufacturing system are all in need of the support of the personnel integration. But the complicated relationship among personnel has caused difficulties in personnel integration. In order to analyze the correlation between personnel in manufacturing system, an analysis method based on the relation degree matrix was proposed, meanwhile the personnel in manufacturing system was classified according to the product life cycle(PLC). The above work has paved the path for the further development of a kind of operation mode for personnel integration in manufacturing system based on PLC (MOPI). The mode is composed of four layers, which are the target layer, the PLC layer, the personnel layer, and the supporting system layer. The above mode was implemented in a local manufacturing enterprise, and positive application effect was achieved.

Abstract: Selecting an appropriate strategy is very important to the Green Manufacturing implementation. Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis is a commonly used tool for strategic management. Here SWOT analysis in combination with AHP is used to the selection of GM strategy. The strategic factors system of SWOT analysis for GM strategy is constructed by analyzing internal and external environments of the enterprise. Then AHP based SWOT analysis is introduced in detail. A case study demonstrates the application of AHP based SWOT analysis in GM strategy selection and shows its feasibility and validity.