In this paper, we propose a new triangular finite element mesh generation method based on simplification of high-density mesh and adaptive level-of detail (LOD) methods for efficient CAE. Mesh simplification evaluating mesh properties is applied to control the mesh properties required for FE mesh, such as the number of triangular elements, element shape quality and size while keeping the specified approximation tolerance. Adaptive LOD methods based on vertex hierarchy according to curvature and region of interest, and global LOD method preserving density distributions are also proposed in order to construct a more appropriate FE mesh. These methods enable efficient generation of FE meshes with appropriate properties for analysis from a high-density mesh. Finally, the effectiveness of our approach is shown through evaluations of the FE meshes for practical use.

In this paper, we propose a new mesh smoothing method for mesh models with measurement noise obtained from a 3D scanner. Our proposed method enables not only the removal of noise from the faces but the preservation and smoothing of features recognized as sharp edges and corners. First, by using the eigen analysis of normal voting tensor, mesh edges composed of sharp edges can be extracted. Second, bilateral filtering is applied to extracted mesh edges to smooth the mesh edges along the direction of the sharp edge. Finally, by applying modified bilateral filtering to the overall mesh, a mesh model with sharp edges smoothed along their directions and measurement noise removed from faces was obtained.

Distributed control systems (DCSs) consisting of a plant, a controller composed of many devices, and an open network interconnecting devices, are now used in many automation areas. For assuring the control performance under the heavy traffic on the network, the simulation of DCS is strongly needed. In the case of DCSs for controlling a mechanical plant, the graphical and cooperative simulation between the controller model and the plant model becomes important to verify the sequence of motions of the plant. For this purpose, we propose a systematic object-oriented-based DCS modeling procedure to efficiently and uniformly develop the DCS simulation model. From this procedure, we can describe the formal description of DCS simulation model based on five object-oriented design patterns which describe the structure and behavior of the DCS. We also propose an event chain mechanism between the statechart-based controller model and the graphical plant model. Finally, the cooperative DCS simulation software is developed by using the Java 3D API.

A seamless design methodology for developing manufacturing cell control software is proposed. The methodology is based both on the graphical specification and on the systematic design procedure of its conversion to the control code. The graphical specification describes the component configuration of the cell and the activity sequence on which the devices should act. An object diagram and an activity-control-condition diagram are introduced for this purpose. The systematic design procedure specifies a clearly-defined conversion from the initial graphical specification to the cell control software code. The conversion consists of three processes: refinement, translation and information. A diagram editor has also been developed to help the programmer carry out this design procedure. Finally, the functionality of the control software generated by using the proposed methodology is validated through co-simulation with a Petri net simulator.

In this paper we propose an inspection method for geometrical tolerances using virtual gauges for measurement with coordinate measuring machine (CMM). For evaluation of the geometrical tolerance virtual measuring gauge as computerized replacement for the real gauge is introduced. The evaluation model for calculation of the virtual gauge uses geometrical constraint for representation of implicit relationships between feature and datums. The implementation evaluation method is small displacement screw method with optimization procedure min-max. Application examples and an extension of small displacement screw method to handle the constraint is provided. We resolve the difficulties for geometrical tolerance inspection, by providing an explicit representation of relationships between features and datums that can be used in an inspection system. Proposed computerized tolerance inspection closely resembles the real gauge measurements and is in concordance with ISO tolerance system.

Some offset surface generation methods for multi-axis machine tools use heuristic methods to consider the various orientations of cutting tools and thereby achieve cutting tool collision avoidance. In this paper in order to realize analytical cutting tool collision avoidance for multi-axis machine tools, the authors propose the application of configuration space, which can represent both the position and orientation of cutting tools simultaneously to offset surface generation.