Rule Based Feed Rate Optimisation for Machine Tools

摘要

Conventional look ahead methods to compute the feed rate for a given geometric path of a machine tool are based on the limitation of the machine-axis' velocity, acceleration and jerk. This paper presents a new method to optimise the feed rate by defining so-called 'rules'. They serve as machine-specific limitations covering linear and nonlinear position dependent machine dynamic effects, e.g. restricting the axis force of a swivelling axis or limiting a cross-talk effect. To enable universal application of the method, these rules are arbitrary, position dependent polynomial functions of the feed rate and its time derivatives. The presented method offers the possibility to treat nonlinear dynamics and restrict unwanted dynamic effects in a systematic way, without limiting the maximum dynamic performance of the machine tool in general. Simulations on a machine tool model, adapted to a real machine, are presented to illustrate the effectiveness of the method.