| dc.description.abstract | Comparing to three-axis machines, five-axis machines perform more efficient and accurate machining. It has become an important tool for modern engineering industries and is widely used in aerospace, shipbuilding, automobile, plastic, mold, and optical industries. However the kinematic equations of five-axis machines are highly complex, and hard to solve. A careless collision between the parts of the machine will be a disaster, because the maintenance is extremely expensive. Therefore, the tool paths should be computed correctly in order to fully exploit the flexibility of five-axis machines.
These methodologies can be considered only either the simplifications of the machine systems or the applications for some special circumstances. The former methodologies obtain mathematical models by simplifying some factors which can be applied flexibly. However, due to the kinematic complication, it is hardly to fulfill all five-axis machining conditions. Consequently, it results in unexpected errors. The latter methodologies, researchers try to limit the scope of the machining conditions to overcome the problems. However, this will deteriorate the flexibility of the resulted equations seriously. In this dissertation, a systematic methodology is developed to obtain the exact kinematic motions among axes of the machine through simple kinematic parameter assignment. Based on these accurate kinematic equations, efficient tool paths are determined.
This research comprises the following tasks: (1) analyze the kinematic relation between the machine tools, and the geometric relation between the cutter and the part surface; (2) develop generalized formulae for the chordal deviation estimation and the scallop height control, which can be applied to all types of five-axis machines; (3) develop the CCPG method, which combines the CDE algorithm and the SHC algorithm in order to improve the machined surface quality; (4) develop the TOS method, which can be used to assign interference-free and smooth tool orientations; (5) combine the TOS method and the CCPG method to form a new tool-path generation procedure. | en_US |