Efficient Curvature-optimized G2-continuous Path Generation with Guaranteed Error Bound for 3-axis Machining

Path generations are a necessary integral part of any automated machining approach using 3-axis robots. Given an input path in form of a piecewise linear curve, we automatically generate an optimized path that lies within a given error bound or tolerance band of the input path. The optimization is targeted at minimizing the processing time of the machining process. As sharp turns require the robot to slow down, we want to minimize the local curvature at each point of the curve. Our approach is an efficient offline algorithm that consists of several processing steps. Ina preprocessing step, we analyze the input path and split it into small groups. The groups are categorized and can be handled independently and locally. We apply a local sleeve concept for complicated groups and a local Bezierapproximation for simple groups. In a post processing step the groups are combined to form a G²-continuous path. Our approach achieves high-quality results that are comparable to the sleeves approach while being significantly more efficient (speed-up of one order of magnitude) when applied to real-world problems.