A method includes: installing a square calibration master on a table, and measuring each of measurement surfaces A, B, and C of the square calibration master by a position measurement sensor attached to a main spindle; calculating a first squareness between the measurement surfaces A and B; calculating a second squareness between the measurement surfaces A and C; calculating a difference between the first squareness and the second squareness; comparing the difference with a preliminarily set difference threshold value; calculating an average value of the first squareness and the second squareness when the difference is equal to or less than the difference threshold value, and calculating a corrected squareness based on an angular deviation and the first squareness or the second squareness when the difference exceeds the difference threshold value; and setting the compensation parameter based on the average value or the corrected squareness.

A method includes: installing a square calibration master on a table, and measuring each of measurement surfaces A, B, and C of the square calibration master by a position measurement sensor attached to a main spindle; calculating a first squareness between the measurement surfaces A and B; calculating a second squareness between the measurement surfaces A and C; calculating a difference between the first squareness and the second squareness; comparing the difference with a preliminarily set difference threshold value; calculating an average value of the first squareness and the second squareness when the difference is equal to or less than the difference threshold value, and calculating a corrected squareness based on an angular deviation and the first squareness or the second squareness when the difference exceeds the difference threshold value; and setting the compensation parameter based on the average value or the corrected squareness.

An example method includes performing a machining operation by providing linear movement of a tool along a feed axis relative to a workpiece while superimposing oscillation of the tool onto the feed axis and providing rotation of the tool relative to the workpiece. During an optimization mode, the machining operation is performed on a first workpiece portion while providing the linear movement at an initial feed velocity, and sequentially superimposing the oscillating at a plurality of different frequencies. An optimal oscillation frequency is determined from the plurality of different frequencies which causes the tool to apply less force to the first workpiece portion at the initial feed velocity than others of the frequencies. During a run mode, the machining operation is performed on a second workpiece portion having a same composition as the first workpiece portion while superimposing the oscillation at the optimal oscillation frequency.

An example method includes performing a machining operation by providing linear movement of a tool along a feed axis relative to a workpiece while superimposing oscillation of the tool onto the feed axis and providing rotation of the tool relative to the workpiece. During an optimization mode, the machining operation is performed on a first workpiece portion while providing the linear movement at an initial feed velocity, and sequentially superimposing the oscillating at a plurality of different frequencies. An optimal oscillation frequency is determined from the plurality of different frequencies which causes the tool to apply less force to the first workpiece portion at the initial feed velocity than others of the frequencies. During a run mode, the machining operation is performed on a second workpiece portion having a same composition as the first workpiece portion while superimposing the oscillation at the optimal oscillation frequency.

Provided is a numerical controller that can suppress a sudden change in the angle of a rotary axis in the vicinity of a singular point and can also be compatible with any machine configuration. A numerical controller for numerically controlling a designated direction of an axis of a movement axis member by two or more rotary axes. The numerical controller comprises a singular point distance calculation unit for calculating each singular point distance from a rotary axis direction of each of the two or more rotary axes and the designated direction based on an operation command, a rotary axis extraction unit for extracting a control rotary axis for controlling the designated direction based on the singular point distance calculated by the singular point distance calculation unit, and a pulse generation unit for generating a pulse for driving the control rotary axis based on the control rotary axis extracted by the rotary axis extraction unit. The rotary axis extraction unit compares the singular point distances with a preset threshold to extract, as the control rotary axis, the rotary axis exceeding the threshold, or comparing the singular point distances with each other to extract the rotary axis having a larger singular point distance as the control rotary axis.

Provided is a numerical controller that can suppress a sudden change in the angle of a rotary axis in the vicinity of a singular point and can also be compatible with any machine configuration. A numerical controller for numerically controlling a designated direction of an axis of a movement axis member by two or more rotary axes. The numerical controller comprises a singular point distance calculation unit for calculating each singular point distance from a rotary axis direction of each of the two or more rotary axes and the designated direction based on an operation command, a rotary axis extraction unit for extracting a control rotary axis for controlling the designated direction based on the singular point distance calculated by the singular point distance calculation unit, and a pulse generation unit for generating a pulse for driving the control rotary axis based on the control rotary axis extracted by the rotary axis extraction unit. The rotary axis extraction unit compares the singular point distances with a preset threshold to extract, as the control rotary axis, the rotary axis exceeding the threshold, or comparing the singular point distances with each other to extract the rotary axis having a larger singular point distance as the control rotary axis.

A controller of a machine tool acquires coordinates of a first machining start point of an eccentric shape in a reference phase of a workpiece around a spindle axis, a second machining start point in an anti-phase, a first machining end point in the reference phase, and a second machining end point in the anti-phase. The controller decides a moving path of the tool in association with rotation of the workpiece at least according to the coordinates of the first start point, the second start point, the first end point, and the second end point to form the eccentric shape around an eccentric axis passing a start point origin between the first start point and the second start point and an end point origin between the first end point and the second end point and thereby controls movement of the tool in association with rotation of the workpiece.

A controller of a machine tool acquires coordinates of a first machining start point of an eccentric shape in a reference phase of a workpiece around a spindle axis, a second machining start point in an anti-phase, a first machining end point in the reference phase, and a second machining end point in the anti-phase. The controller decides a moving path of the tool in association with rotation of the workpiece at least according to the coordinates of the first start point, the second start point, the first end point, and the second end point to form the eccentric shape around an eccentric axis passing a start point origin between the first start point and the second start point and an end point origin between the first end point and the second end point and thereby controls movement of the tool in association with rotation of the workpiece.

To calculate a holding position of a workpiece with high accuracy and place the workpiece in a placement position with high accuracy based on the holding position. A workpiece holding apparatus includes: holding means for holding a workpiece; first information acquisition means for acquiring three-dimensional information of the workpiece held by the holding means; position calculation means for calculating a lowest center point of the workpiece as position information of the workpiece based on the three-dimensional information of the workpiece acquired by the first information acquisition means; and control means for calculating a placement position where the workpiece is to be placed based on the position information of the workpiece calculated by the position calculation means and controlling, based on the placement position, the holding means so as to move the workpiece to the placement position and place the workpiece in the placement position.

To calculate a holding position of a workpiece with high accuracy and place the workpiece in a placement position with high accuracy based on the holding position. A workpiece holding apparatus includes: holding means for holding a workpiece; first information acquisition means for acquiring three-dimensional information of the workpiece held by the holding means; position calculation means for calculating a lowest center point of the workpiece as position information of the workpiece based on the three-dimensional information of the workpiece acquired by the first information acquisition means; and control means for calculating a placement position where the workpiece is to be placed based on the position information of the workpiece calculated by the position calculation means and controlling, based on the placement position, the holding means so as to move the workpiece to the placement position and place the workpiece in the placement position.