Research On Thermal Errors Compensation Techniques In Machining Center's On-line Inspection Software

On requirement of AMT, the dissertation offers one of the most important techniques in CAQC (computer aided quality control) for CIMS, namely how to carry out on-line inspecting and to enhance the inspecting accuracy in MC (Machining Center). On the basis of MBS(multi-body system) , the creative aspects in this paper are mainly concerned with the technology of inspecting system for MC, the modeling of thermal errors, the identification of parameters ,the analysis and compensation and the disposal of sampled data. Based on Windows 2000 operating system, the software of thermal error compensation techniques in MC's On-line inspection has been developed by help of Visual Basic 6.0 and Access. The main contents of the study are as fellows:By view of three-axis vertical MC, study its structure, the components of the inspecting system and its working principle, research the main source of errors and its compensating methods, and mainly analyze the system errors of the probe, geometric errors and thermal errors of MC. Based on the theory of MBS, studying how to model the inspecting errors for three-axis vertical MC, present the comprehensive errors model to offset probe errors, geometric errors and thermal errors.Studying the placement of the thermal sensor, analyzing the characteristics of three-axis vertical MC, comparing multivariable regression analysis technology and artificial neural networks in the course of thermal error modeling, the identification to thermal errors' offset has been developed.On the basis of modeling of thermal error compensation, the software has been developed, relational database of system setting, errors compensation and program have been developed, by which probe errors, thermal errors and geometric errors can be properly compensated. Therefore the accuracy of inspecting results can be improved.(5) A series of tests have been performed on the platform of MAKINO three-axis vertical MC and Renishaw MP3 probe. It has been proved that the accuracy of the machine based On-line inspection after geometric errors compensation is improved by 52.2%, the accuracy of inspect system improved by 80.9% after thermal errors compensation. The results verify the effectiveness of the method.