An Efficient Feedrate Dynamic Planning Method in CNC System

摘要

In this paper, a real-time feedrate dynamic planning method in CNC system is studied. Machine feedrate is affected by interference conditions from external environment. Commonly used machining modes such as Exact Stop Mode and Continuous Mode are both influenced by emergency stop, feedrate reset and feedrate override signals. The corresponding dynamic planning method is studied in this paper. Segment linking method is applied in Continuous Mode, guarantees constant velocity while traversing multi-blocks, and ensure acceleration within limits. In Exact Stop Mode, inference signals only affect the current segment. In Continuous Mode, always not only the current velocity profile is alternated, but also the successor blocks are affected. The proposed method response in time, the current interpolation period recalculates time parameter when influence signal comes and starts to response in action. The controller changes its logic as soon as interference signal comes and adjusts trajectory planning profile in real-time. The proposed method acts before interpolation, in Cartesian space. Experimental results show the effectiveness of the proposed dynamic planning method.