The Study And Development On The Coordinate Precision Measurement System

This paper gives a presentation about the study and development on the Coordinate Measurement Machine used in inspecting three dimensional pipe accessory. This research project comes from the need in practice.By the analyses to the function needed, the precision required and the other practical information, we made the plan: the main structure is fixed-bridge type, which has good rigidity. The displacement sensor is grating sensor, which has the merit of high precision and easiness to be digital. The probe is hard needle type. It will be convenience to become automatable for we use data acquired card to pass data to microcomputer.We realize multi coordinate systems conversion method. We establish the mathematical model of the coordinate system conversion. For there is manufacture error and inspect error during the data, so we bring forward that we can use Chauvenet rule for several times to-eliminate unsuitability data. We use linear regression analyses to get coordinate conversion parameter and make the result is optimal.We use Visual Basic 6.0 to programme data acquire and process software to realize every arithmetic. We use database technique to store and transfer data, which can make software numeric. We try to make the interface more friendly and operation more easy in practice by improve the software.We analyse the reason why the error and the uncertainty of the CMM appear and the way we resolve it. We can draw the conclusion that the CMM we developed achieve the design request by experiment data.