Research In The New Method Of Identification And Complement Application For CNC Errors

Precision and high-precision manufacturing is now becoming important integrity of the mordern manufacturing as the qucik development of technology. The accuracy of numerical controlled machines is the key factor to the precision of manufacturing. CNC machines play more and more important role in today's work and life. The volumetric errors of CNC machines contain followings, such as linear displacement errors, straightness errors, squareness errors, angle errors and rigid errors. Totally speaking, the CNC machines contain 21 errors due to its complicated structure. How to improve the accuracy of the CNC machines is now becoming the key problems in the world. The best way to improve the accuracy of CNC machines is to identify the errors and complement them with sofeware. The paper makes such useful research and discuss as followings below.(1) The paper introduces a new measurement based on LDDM- Laser step diagonal measurement called the laser vector step-diagonal measurement. It is a new error measurement method which executes a diagonal as a sequence of single-axis motions and combines the vector calculation. It executes a diagonal as a sequence of single-axis motions. It can enable the identification of all the volumetric error components including 3 linear errors, 6 Straightness errors and 3 Squareness errors.(2) The paper also analyzes the accuracy of measurement and proposes a new formulation to accurately identify volumetric errors even under the existence of setup errors. The effectiveness of the proposed modified identification scheme is investigated experimentally by an application example to a high-precision machine tool. (3) The paper also makes some research in the straightness and squareness errors change due to the thermal affects. The development of thermal errors from a cold machine to a temperature stable state may concern in many cases hundreds of micrometers. These facts make it extremely difficult to measure the influence of the thermal affects on the geometric characteristics of a certain machine tool. Reported here is a novel method capable of covering the development of all the machine straightness and squareness errors accompanied with the monitoring of the relevant machine temperatures. At last, the paper sets up the modle to succefully reduce the error from 25.32 micrometers to 8.57 micrometers.