Method and apparatus for characterizing and enhancing the dynamic performance of machine tools

A method for assessing a dynamic multi-axis positional accuracy of a machine tool having a first axis slide having a first motion axis and having a second axis slide having a second motion axis that is perpendicular to the first motion axis, comprising:

• (a) electronically instructing the machine tool to drive the first axis slide along the first motion axis using a first pattern of dynamic excitation commands;
• (b) while performing step (a), electronically instructing the machine tool to drive the second axis slide in a second pattern of dynamic excitation commands along the second motion axis,
• (c) while performing steps (a) and (b), measuring a first actual motion of the first axis slide along the first motion axis,
• (d) while performing steps (a) and (b), measuring a second actual motion of the second axis slide along the second motion axis,
• (e) evaluating the dynamic multi-axis positional accuracy of the machine tool by comparing (1) a first ideal relationship between the first pattern of dynamic excitation commands and the second pattern of dynamic excitation commands with (2) the first actual motion of the first axis slide along the first motion axis and the second actual motion of the second axis slide along the second motion axis.

A method for assessing a dynamic performance of a machine tool having a first axis slide that has a first motion axis and a second axis slide having a second motion axis that is perpendicular to the first motion axis, comprising:

• (a) electronically instructing the machine tool to drive the first axis slide along the first axis using a first pattern of dynamic excitation commands comprising displacements less than about one-half inch to generate a first machine-tool-response;
• (b) deriving from the first machine-tool-response a first quantification of a measurable merit of machine tool performance indicating dynamic cross-axis stability of the machine tool comprising:
• (i) measuring a first actual motion of the second axis slide along the second motion axis in response to the first pattern of dynamic excitation commands, and
• (ii) comparing the first actual motion with an expected null response along the second motion axis to establish a first quantification of the dynamic cross-axis stability of the machine tool.

A method for assessing a dynamic performance of a machine tool having a first axis slide that has a first motion axis and a second axis slide having a second motion axis that is perpendicular to the first motion axis, comprising:

• (a) electronically instructing the machine tool to drive the first axis slide along the first axis using a first pattern of dynamic excitation commands comprising displacements less than about one-half inch to generate a first machine-tool-response;
• (b) deriving from the first machine-tool-response a first quantification of a measurable merit of machine tool performance indicating dynamic cross-axis stability of the machine tool comprising:
• (i) measuring a first actual motion of the second axis slide along the second motion axis in response to the first pattern of dynamic excitation commands,
• (ii) comparing the first actual motion with an expected null response along the second motion axis to establish a first quantification of the dynamic cross-axis stability of the machine tool;
• (c) electronically instructing the machine tool to drive the first axis slide along the first motion axis using a second pattern of dynamic excitation commands comprising displacements less than about one-half inch, the second pattern being different from the first pattern of dynamic excitation commands;
• and
• (d) deriving a second quantification of the measurable merit of machine tool performance indicating dynamic cross-axis stability of the machine tool from the second pattern of dynamic excitation commands.