Analyzing traditional tool positioning strategies, it was pointed out that most of strategies were based on local differential geometry, seldom could be applied in 4-axis machining, theoretical approximation could not be eliminated, and perfect optimum could not be achieved as well. The principle of global curvature fitting is a basic rule that global tool positioning strategy should be complied, it is especially valuable in practice. A detail description and flow chart of the nearest curve method was present, the practical calculations and experiments focused on 4-axis machining that seldom discussed were accomplished, the advantages and reliability of the method were also be proven by contrast with the traditional methods.
China Mechanical Engineering
local differential geometry
global curvature fitting principle
nearest curve method