Advanced Materials Research Vols. 655-657

Abstract: On the base of summarizing and contrasting the objectives of sequencing problem in mixed model assembly lines (MMAL) , and in consideration of the influence sequence-dependent setup times , a objective is proposed to minimize the total unfinished works and idle times over all jobs and stations . And the corresponding model is presented. To solve this model, a modified genetic algorithm is proposed to determine suitable sequences. Comparing with the Lingo 9 software, the proposed GA turns out to have a good ability to solve the sequencing problems.

Abstract: This paper focuses on major issues in production process control of automobile injection molds based on process perception, such as manufacture resource perception, exchange in three-dimensional model (3D), production planning and scheduling, manufacture process planning (tool path and assembly sequence). After a survey of them, we propose a method for the construction of computer-aided production process control platform. 1) Define the networked manufacture semantic/data model and an encapsulating approach to efficiently manipulate manufacturing resources. 2) Develop structural multi-view data models for the design information of automobile molds transferring in 3D. 3) Propose a production planning and scheduling arithmetic. 4) Develop a variation accumulation model for manufacturing process control. 5) Integrate the tool path and assembly sequence planning of injection molds by using a variation accumulation model. 6) Integrate the existing and/or developed models to the new system. Finally we introduce a validation method and discuss the prospect to the accurate control of production process.

Abstract: This paper in aircraft assembly at home and abroad on the basis of the technical investigation and through the study of domestic aircraft digital assembly backward, serial design, repeatedly modify, multiple test equipment, long production cycle, high cost problems, presented a lightweight model based on process of visual assembly technology. And elaborated this technology to the airplane rig production line vital significance, and proposed the concrete implementation method. Finally adoption of the instance can be seen, lightweight visual assembly of the model based on process technology, the domestic use of advanced assembly technology, construct advanced assembly lines, improve the assembly efficiency, reduce assembly costs are of important significance.

Abstract: In order to ensure the stationarity of the aircraft fusagle automatic adjustment and reduce the fluctuation of the drive force, the redundant actuation optimal algorithm is presented in this paper. Firstly, using Newton-Euler method, the dynamics equations of pose adjustment system are established. Based on the equations, the driving forces can be sovled. Secondly, according to the constraint conditions and pose adjustement process, Cubic Polynomial trajectory planning algorithm is proposed for the aircraft fusagle automatic adjustment. Thirdly, in order to reduce the fluctuation of the drive force, the redundant actuation optimal algorithm is presented. Simulation results show that the presented trajectory planning algorithm has good dynamic characteristics and satisfies engineering requirements. Moreover, the differences between the solutions of optimal algorithm and ideal drive forces are much less than the differences between the minimal norm least square solution and ideal drive forces.

Abstract: Assembly design and simulation plays a very important role among all stages of product design, and is the fundamental guarantee to improve the assembly performance of product. However, in current assembly design and simulation process, the detailed assembly path and the assembly position and orientation of parts are all needed to be defined through human-computer interaction. Especially when a product contains quantities of parts, there will be so many human-computer interactions to do, which can greatly increase the burden of designers. For this reason, the purpose of this paper is to study an automatic assembly method to reduce the complexity in the definition of assembly design and simulation. Firstly, we studied the intrinsic relationship between the Assembly Feature Pair (AFP) and assembly behaviors of a part, and it’s our belief that the AFP pattern of one part determines its assembly behaviors. And then we proposed an automatic product assembly method based on AFP, by which one only need to enter or specify certain parameters to achieve the assembly design and simulation of a part. Finally, a simple toolset developed based on CATIA and DELMIA using this method was introduced, and an example was given to verify the validity of this approach.

Abstract: Automobile steering devices are key parts that change driving direction of automobiles and maintain them stable in a straight line. In order to construct steering gear model quickly and accurately, this paper does parameterized modeling to automobile steering gear through knowledge engineering module of CATIA software. By using Visual Basic can be interactive interface created, modeling can be recorded and modified procedure through the macro mode, and write program code, by using process of external access to realize secondary development of CATIA and complete construction of steering gear model library. Users input corresponding design parameter values that can automatically call parts model; therefore, it shortens product design cycle and improves design efficiency of product.

Abstract: This paper studied how to quickly draw the roll engineering drawing thorough ARX application program, introduced and analyzed the layer, linear, size tolerance Settings, and geometric tolerance Settings. On this basis, citing specific examples will be described, and listed the specific examples to explain. At last speaked on design idea and the development steps for roll rapid drawing system, completed the ARX applications of manufacturing circular tube roll. Those ARX application program loaded in the AutoCAD2002, automatically drawed mechanical drawing of roll by inputting characteristic value, liberated the drawing technicist, saved plenty of manpower and material resources.

Abstract: The paper presents a structure and functions of an expert system for aided design of rice harvester chassis systems. It was developed on basis of a detailed analysis of the design process, including knowledge bases regarding chassis systems automated design, a community of parameterized parts and assemblies and interference engine. In the creation of the system, Visual C++, Pro/Engineering and Oracle database were used. This system is characterized by a rule-oriented representation of knowledge, forward chaining inference methods, and graphic representation of the design results by parameterized technology. The industrial application of this system proved its high reliability and accuracy.

Abstract: For predicting the tool life combine the ant colony optimization(ACO) with the back propagation (BP) neural networks, use the the ACO to train BP neural network, build the prediction model based ACO-BP neural network. Some disadvantages are overcame in the BP algorithm, such as the low convergence speed, easily falling into local minimum point and weak global search capablity in the prediction process. Satisfies the requirement of global search capability and the robustness of the model. The experiment results show the prediction model has high precision in predicting the tool life. By the prediction model can provide a reasonable basis for planing production schedule and cutting tool requirement, calculating the cost, selecting the machining parameters,etc.

Abstract: In this paper, Bayesian network based expert system is built for seismic performance evaluation. Unlike the regular rule-based expert system which allows only unidirectional reasoning with strict complete data entry sets, the Bayesian network based expert system can perform bidirectional inference based on incomplete information when the prior probability distributions are given. Seismic performance evaluation is a task that often needs experiences to draw a conclusion under insufficient information circumstance, which made the Bayesian network- based expert system well qualified for the job, and the example also illustrates this point.