Presented in the paper is a tool-path planning algorithm for direction-para
llel area milling consisting of three modules: (1) finding the optimal incl
ination; (2) calculating and storing tool-path elements; and (3) tool-path
linking. For the optimal inclination, we suggest an algorithm that selects
an inclination by reflecting the shape of the machining area as well as the
tool-path interval. We make use of the concept of a monotone chain and the
plane-sweep paradigm to calculate the tool-path elements. The concept of a
monotone chain brings clarity and tight-time complexity to the proposed al
gorithm. The tool-path linking problem is modeled as a TPE-Net (tool path e
lement net) traversing problem. For the two direction-parallel milling topo
logies, one-way and zigzag, tool-path linking algorithms are proposed. Empi
rical tests show that the proposed algorithm fulfils its requirements. (C)
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