Key Engineering Materials Vols. 407-408

Abstract: Designing a flexible fixture is much more complicated. In this paper a collaborative environment was introduced for flexible fixture design. The tasks involved in fixture design are analyzed and decomposed into five subtasks, which are assigned to workgroups by a project manager. The workgroups can be distributed in different departments or in different locations geographically. The framework of collaborate design environment is constructed. Each workgroup is responsible to a certain job. However, the information needed for flexible fixture design is shared among these workgroups. The information exchanging and management in the environment are expressed with a block diagram. Finally, an example of flexible fixture for manufacturing a thin-walled workpiece is employed to illustrate the efficiency of the collaborative environment.

Abstract: In order to solve the collaborative manufacturing unit (CMU) selection problem in the networked cooperative manufacturing environment, a sorting adaptive genetic algorithm is proposed. To obtain the optimal executive manufacturing process, the objective function is constructed considering manufacturing cost and product load rate of candidate CMUs under time-sequence constraint. The embedded subtask scheduling procedure in sorting adaptive genetic algorithm is used to ascertain the penalty cost for the tardiness of the task. Finally, a case study is implemented to verify the feasibility of the proposed approach. The results show that the proposed model and algorithm can obtain satisfactory solutions.

Abstract: A new approach to the problem of part recognition is proposed by using maximum mutual information. The method applies entropy to measure image feature, combined with color information and local shape information, and uses mutual information as a new matching criterion between the images for image recognition. This method solves the problem that histogram algorithm can not represent the spatial information. This method not only has the feature of translation invariant, but also avoids image segmentation which may lead to a complex calculation, so it can be realized easily. The result shows that proposed approach is accuracy, stability, and reliability in the processing of machine part image recognition.

Abstract: For taking advantage of high speed machining(HSM) in complex curved surfaces as impeller, the virtual manufacturing technology is adopted before the real machining, which can eliminate tool collision interference phenomenon of the trial cutting, avoid complicated process of trial test , forecast machining results efficiently. The simulation tests were proceeded to the each impeller procedure NC program by using the VERICUT virtual manufacturing soft to modeling five-axis machine tool HSM600U, and the result compared with the real machining is identical with one other. So it is tested that applying this technology can forecast the machining process truly.

Abstract: This paper reports the work of web-based auto-design machining process of special bearing. A template-based process planning method is proposed for auto generating machining process of special bearing, including turning process and grinding process of inner ring or outer ring. Process templates are customized to generate process, procedures size and size tolerance are calculated according to procedure size database. A web-based process planning system is developed based on the proposed method. The use of the system is illustrated with an example.

Abstract: NC geometric cutting simulators are a widely used software. However, it is difficult to represent the cutting load, tool deflection and tool wear caused by physical phenomena. The purpose of this research is to develop a NC geometric cutting simulation that will be able to easily calculate these phenomena during simulated machining. This paper describes the calculation algorithms of cutting loads, deflections, and wear of tools based on a removal volume, and the implementation of the NC geometrical cutting simulator. The removal volume is an interference area calculated between a workpiece and a swept volume of the tool movement, and the removal volume at each height is calculated at the same time. As a result, it is confirmed that the proposed algorithm is able to estimate the cutting load and the tool wear.

Abstract: A new kind of numerical control (NC) system for machining shafts with non-circular cross-section is proposed in this paper. It is composed of one X-Z platform, a special micro-feed mechanism driven by a simple cam, and one rotating tool. A new circumferential curve interpolation algorithm based on the cam mechanism is put forward to machine the shafts with any non-circular cross-section, and its efficiency is verified by the simulation. Especially, the larger cutting force can be obtained by use of individual rotating tool. The requirement on response speed is no longer strict. It shows more flexibility on manufacturing.

Abstract: This paper proposed configuration three-level matching model based on modular product structure in order to solve the product configuration design problem in mass customization (MC). According to the product structure and the features of configuration design, the model divided the configuration course into three parts as first-level complete matching, second-level similarity matching and third-level correlation matching. Firstly obtained standard module that meets clients’ demands by retrieval algorithm of first-level complete matching and similar module of the customized by mathematical model of second-level similarity matching. Then based on them, analyzed the correlation matrix among modules and associated attributes of modules interface, and established the mathematical model of third-level correlation matching and realized the optimum combination of modules. Finally, verified the model by examples. The results indicate that this model could effectively solve the low-efficiency problem of deformation module recombination design in traditional product configuration so to rapidly respond to clients’ customization demands.

Abstract: There are two key problems in the manufacture process of impeller, one is the collision of tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. UG software was used to solve those problems. Tool tip position was solved by UG. The control algorithm of collision-free cutter-axis was described and applied. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. The impeller produced by it was qualified. It indicated that the method of tool vector control was feasible.

Abstract: The production organized in flexible manufacturing cells (FMC) can be a complicated issue when they are constrained by machines, robots, equipment and some other resources. Since machines and robots are the main bottleneck to the efficiency of FMC, this paper focused on the modeling and scheduling problem constrained by machines and robots. A common model representation, colored timed Petri net (CTPN) was utilized to build a FMC model constrained by robots and machines, which was then transformed to the simulation model. The scheduling problem was studied to establish a mathematical model of the FMC constrained by machines and robots. According to the model, a genetic algorithm was proposed to search an optimal solution by using an indirect coding of scheme. The effectiveness of the proposed algorithm was validated via an instance and the comparison with the result from the solution of simulated annealing algorithm.