Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10327134 | Robotics and Computer-Integrated Manufacturing | 2005 | 17 Pages |
Abstract
The problem of specifying the feedrate variation along a curved path, that yields minimum traversal time for a 3-axis CNC machine subject to constraints on the feasible acceleration along each axis, is addressed. In general, this time-optimal feedrate incurs “bang-bang control,” i.e., maximum acceleration/deceleration is demanded of at least one axis throughout the motion. For a path defined by a polynomial parametric curve r(ξ), we show that the (square of the) time-optimal feedrate can be determined as a piecewise-rational function of the curve parameter ξ, with break-points corresponding to the roots of certain polynomial equations. Furthermore, this type of feedrate function is amenable to a real-time interpolator algorithm that drives the machine directly from the analytic curve description, eliminating the need for linear/circular G code approximations. The theoretical and computational aspects of such time-optimal feedrate functions are presented, together with experimental results from their implementation on a 3-axis mill driven by an open-architecture software controller.
Keywords
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Physical Sciences and Engineering
Computer Science
Artificial Intelligence
Authors
Sebastian D. Timar, Rida T. Farouki, Tait S. Smith, Casey L. Boyadjieff,