Evolution of methods of assessing the accuracy of metal-cutting machines. 2. Evolution of concepts and models used in assessing the accuracy of metal-cutting machines

The evolution of methods used in assessing and monitoring the accuracy of metal-cutting machines is considered. Changes in terminology and in the concept of accuracy are discussed. Relations between the evolution of accuracy and the methods used for its determination are presented, in the context of the most important developments responsible for machine-tool accuracy. The development of models of machine-tool accuracy is reviewed, and the corresponding mathematical apparatus for the accuracy assessment is presented. The applicability of the various approaches is determined.