Characterising the effects of shape on tool path motion

This paper presents a methodology for a priori shape characterisation of tool path motion. Many current methods to describing tool path motion require explicit knowledge of the motion control algorithms implemented on a specific machine. Either a method proposes novel algorithms or requires knowledge of the algorithms currently implemented in a given machine's controller (e.g. minimum jerk, harmonic jerk and minimum jounce). This paper provides a method, that may be applied on any machine, to characterise motion in terms of a tool path's intrinsic shape properties. The characterisation identifies the achievable set of kinematics for a tool path of a given shape without the need for physical machining and a knowledge of the motion control algorithms. The characterisation may be employed in a pre-processing manner to inform the selection of NC file tool path motions. This can therefore help to reduce the material and energy resources being consumed during iterative machining trials and so improve the efficiency and productivity of the manufacturing process. •Free motion tests on a machine's axes enable identification of the maximum magnitudes of the kinematic vectors for a tool path of a given shape.•Appropriate kinematic constraints on the general kinematic vector equations enable suitable characterisation of tool path motion to be derived.•The approach does not require knowledge of the motion control algorithms implemented on a given machine's controller.•This methodology can be applied to any machine in order to obtain a suitable characterisation of tool path motion.