Abstract: A controller uses detection information of a contact sensor or time-series data of a detection value related to a drive motor included in a rotation mechanism and/or a feed mechanism to acquire a coordinate value when a cutting tool comes into contact with a to-be-cut object or a component. The controller determines a relative positional relationship between the cutting tool and a rotation center of the to-be-cut object based on coordinate values when the cutting tool comes into contact with the to-be-cut object subjected to turning work or a reference surface whose relative positional relationship with the rotation center of the to-be-cut object is known at least at two positions different from a rotation angle position of the cutting tool during the turning work.

Abstract: A cutting apparatus includes a cutting tool having a cutting edge, an excitation part structured to apply excitation to the cutting tool, and a drive part structured to apply a voltage to the excitation part to reciprocate the cutting edge of the cutting tool. The excitation part suppresses residual oscillations by applying excitation that contains an excitation force of components of frequencies higher than a resonance frequency and has an excitation force of the resonance frequency suppressed. The excitation part applies a first excitation, and applies a second excitation after an elapse of a time 0.5 times as long as a resonance period from timing at which the first excitation is applied to suppress residual resonance oscillations.

Abstract: Provided is a cutting method of cutting, with a diamond cutting tool, a metal material having at least a solid solution layer on a surface, the solid solution layer containing nitrogen atoms as interstitial solid solution atoms. In this method, cutting is performed in a region where a nitrogen concentration is equal to or greater than a predetermined concentration, and cutting is not performed in a region where the nitrogen concentration is less than the predetermined concentration.

Abstract: A controller uses detection information of a contact sensor or time-series data of a detection value related to a drive motor included in a rotation mechanism and/or a feed mechanism to acquire a coordinate value when a cutting tool comes into contact with a to-be-cut object or a component. The controller determines a relative positional relationship between the cutting tool and a rotation center of the to-be-cut object based on coordinate values when the cutting tool comes into contact with the to-be-cut object subjected to turning work or a reference surface whose relative positional relationship with the rotation center of the to-be-cut object is known at least at two positions different from a rotation angle position of the cutting tool during the turning work.

Abstract: A movement controller controls a feed mechanism to move a vibration device relative to a workpiece. A vibration controller controls vibration of piezoelectric elements of the vibration device. The vibration controller acquires a status value indicating a vibration control status and detects contact between a cutting tool and the workpiece or the like based on a change in the status value. The vibration controller acquires at least one among energy consumption required for the vibration and a resonance frequency as the status value. The vibration controller determines a relative positional relationship between the cutting tool and a rotation center of the workpiece based on coordinate values of at least two contact positions.