Research On New Error Compensation Techniques For NC Machine Tools

Pursuing the high precise and efficient manufacture and the low cost productions impose higher demand upon the NC machine tools, which is dominant in the modern manufacturing. On the basis of research achievements in existence, an error auto-modeling method for NC machine tools based on MBS theory was proposed. In the method feature matrixes the essential elements of an error model were regarded as objects, and a database of feature matrix function was built. Corresponding relationships between features and feature matrixes make deciding features the key of error modeling. As to features, they are decided by the motion way of adjacent bodies. An error auto-modeling system was developed according to the method, from which expanded to an error inspecting and controlling system. The error models that modeling automatically are used for NC machining error compensation and on-line inspection error compensation.The thesis' main contents are as follows:1. Domestic and international NC technology developing trend, current research situation and achievements of error modeling and error compensation were studied. Analyzed advantages and disadvantages of all the error modeling methods and the error compensation methods in existence, and analyzed domestic and international auto-modeling methods and their characteristics.2. The MBS error modeling methods and its specialty were introduced. Feature signs were defined to describe the information of structure and motion way of machine tools. The corresponding relationships between the features and the feature matrixes were explained.3. The essential and the orderliness of the MBS method were proposed.4. An error auto-modeling method based on MBS theory was proposed. A feature matrix function database was built. The deducing rules for error modeling were set. A system of cooperation of VC and MATLAB programming was developed.5. Error compensation methods of on-line inspection and NC machining were introduced.Make full use of computer abundant resources and functions to complete lots of error modeling works. An error model can be gained automatically. Due to the advantages of the MBS error model method, it can be used abroad in error auto-modeling of kinds of machine tools, coordinate measuring machines, robots, and so on.