Waveform display device and waveform display method

A waveform display device comprising:

• a position information acquisition unit configured to acquire, from a controller for controlling a machine tool, position information indicating a position of a driving axis of the machine tool during machining of a workpiece;
• a machine information acquisition unit configured to acquire machine information indicating axis configuration of the machine tool set to perform the machining of the workpiece;
• a machining point coordinate calculation unit configured to calculate a coordinate for each of a plurality of machining points of a tool installed in the machine tool, on the basis of the position information and the machine information;
• a reference surface setting unit configured to set parameters a, b, c, and d of an equation representing a reference surface corresponding to a targeted machining surface of the workpiece, the parameters being set based on at least three command values not on a same line for machining of a flat surface out of command values of the plurality of machining points to the machine tool based on a machining program;
• a distance calculation unit configured to calculate a distance from each of the coordinates calculated for the plurality of the machining points to a vertical direction to the reference surface set by the reference surface setting unit;
• and
• a waveform display unit configured to display the calculated distances in a waveform,
• wherein the reference surface setting unit sets the parameters so that the reference surface that has a normal vector directed to a positive direction involved in an inner product of the normal vector and a tool vector, the tool vector being directed from a tip to a root of the tool installed in the machine tool, and
• wherein the equation is defined as follows:
• ax+by+cz=d,
• where a, b, c, and d are the parameters set by the reference surface setting unit based on the at least three command values not on the same line for the machining of the flat surface out of the command values of the plurality of machining points to the machine tool based on the machining program, x represents x-axis in a three-dimensional Cartesian coordinate system, y represents y-axis in the three-dimensional Cartesian coordinate system, and z represents z-axis in the three-dimensional Cartesian coordinate system.