Machine tools are recognized as key elements of manufacturing systems, and product quality and cost mainly depend on performances of the machine tools. Much progress has been made in the machine tool technologies, aimed at improving the performances of the machine tools from various viewpoints, such as accuracy, reliability, productivity, and flexibility. The machining accuracy is one of the most important characteristics of the machine tools. From the viewpoints of the design and the manufacturing of the machine tools and their components, one of the important issues is to clarify the relationships between the kinematic motion deviations of the machine tools and the geometric tolerances of the components, such as the guide ways and the bearings. The objectives of the present research are to establish mathematical models representing the kinematic motion deviations of the machine tools, on the basis of the geometric tolerances of the components, and to apply the models to theoretical analysis of the kinematic motion deviations of the machine tool components.

The objectives of the present research are to investigate relationships between kinematic motion deviations of machine tools and geometric tolerances of their components, to propose mathematical models representing kinematic motion deviations of five-axis machining centers, and to apply the models to analysis of the kinematic motion deviations of five-axis machining centers. A set of models is proposed to represent kinematic motion deviations of both the linear tables and the rotary tables, based on the geometric tolerances of the guide-ways connecting the components. By combing the models, three models of the five-axis machining centers are developed and applied to the analysis of the standard deviations of the shape generation motions of the tools and the workpieces. The proposed models provides us with a systematic method to analyze and to estimate the kinematic motion deviations of the five-axis machining centers, based on the geometric tolerances of the guide-ways connecting the components.

The geometric dimensioning and tolerancing is one of the most important characteristics of machined parts. A systematic method is proposed in the paper to simulate the shape generation processes in turning operations, to estimate the geometric dimensioning and tolerancing of the turned faces, based on the machining parameters. The simulation model includes both the models of the shape generation motions considering kinematic motion deviations and the cutting tool geometries. The shape generation motions with deviations are mathematically described by combining 4 by 4 transformation matrices. A set of points on the turned faces are generated through the simulations, and an assessment surface is obtained as the datum reference to estimate the 3-dimensional (3D) tolerances, based on the points generated by the turning process simulations. The proposed method provides us with a systematic method to estimate the geometric dimensioning and tolerancing in the turning processes including the kinematic motion deviations.

The surface roughness is one of the most important characteristics of machined parts. A systematic method is proposed in the paper to simulate the shape generation processes in the boring operations and to estimate the surface roughness of the generated faces, based on the machining parameters. The simulation model includes both the models of the shape generation motions considering kinematic motion deviations and the cutting tool geometries. The shape generation motions with deviations are mathematically described by 4 by 4 transformation matrices. A set of points on the bored holes are generated through the simulations, and an assessment surface is obtained as the datum reference to estimate the 2-dimensional (2D) and the 3-dimensional (3D) surface roughness, based on the points generated by the boring process simulations. The proposed method provides us with a systematic method to estimate the surface roughness in the boring processes including the kinematic motion deviations.

Parallel link robots are now being applied to various assembling tasks for small products and components. One of the important issues for design of the parallel link robots is to improve their kinematic motion deviations due to the complex link structures. The kinematic motion deviations of the parallel link robots are deeply influenced by the geometric deviations of the components, such as joints and links. A systematic design method is required for specifying suitable geometric tolerances of the joints and the links, in order to improve the kinematic motion deviations of the parallel link robots. The objective of the present research is to establish a computer-aided design system for specifying a suitable set of the geometric tolerances of the components considering the trade-off between the requirements on the kinematic motion deviations and the ease of the manufacturing processes. A mathematical model is formulated to represent the standard deviations of the kinematic motions of the end effectors, based on the tolerance values of the joints and the links. A systematic method is proposed here, by applying an optimization method, to determine a suitable set of the tolerance values of all the joints and the links under the constraints on the kinematic motion deviations of the end effectors. The method is applied to some design problems of the geometric tolerances of the parallel link robots.