The present invention relates to an apparatus and to a method for compensation of errors of a numerically controlled machine tool, which has at least one controllable machine axis for relative positioning of at least one workpiece relative to one or more machining devices. The method comprises detecting actual measured values of at least one input variable describing a state of the machine tool by means of sensors on the machine tool, providing at least one compensation parameter to be utilized by a control device of the machine tool on the control device of the machine tool and compensating errors on the machine tool on the basis of the compensation parameter provided to the control device. The compensation comprises the compensation of thermal errors, the compensation of geometric errors and the compensation of errors on the basis of the dynamics of the machine.

A method for calibrating a CNC machine including providing instructions for machining a surface of a distortion-free object, selecting a true axis of movement of a toolhead of the machine using the instructions, instructing the toolhead to travel on an object to be machined along the true axis of movement, but where the toolhead actually travels along an actual axis that is deviated from the true axis as a result of the surface distortions on the object to be machined, selecting multiple points along the actual axis traveled by the toolhead on the object to be machined, comparing the distance of the multiple points along the actual axis from the true axis to determine offset amounts from the true axis corresponding to a lack of straightness of the object to be machined, and modifying the instructions to compensate for the offset amounts before uploading the instructions to a CNC controller.

A servomotor control device includes: a servomotor; a driven body that is driven by way of the servomotor; a connection mechanism that connects the servomotor and the driven body to transmit power of the servomotor to the driven body; and a motor control unit that controls the servomotor, in which the motor control unit includes: a force acquisition section that acquires a drive force acting on the driven body at a connection part between the connection mechanism and the driven body; and a rigidity estimation section that estimates a magnitude of rigidity of the connection mechanism, based on position information of the servomotor and a drive force acquired by the force acquisition section when causing the servomotor to rotate in a state mechanically fixing the driven body.

A method for calibrating a CNC machine including providing instructions for machining a surface of a distortion-free object, selecting a true axis of movement of a toolhead of the machine using the instructions, instructing the toolhead to travel on an object to be machined along the true axis of movement, but where the toolhead actually travels along an actual axis that is deviated from the true axis as a result of the surface distortions on the object to be machined, selecting multiple points along the actual axis traveled by the toolhead on the object to be machined, comparing the distance of the multiple points along the actual axis from the true axis to determine offset amounts from the true axis corresponding to a lack of straightness of the object to be machined, and modifying the instructions to compensate for the offset amounts before uploading the instructions to a CNC controller.

A method for virtually calibrating a CNC machine including the steps of selecting a true axis of movement of a toolhead of the CNC machine, instructing the toolhead to travel along the true axis of movement, selecting multiple points along an actual axis traveled by the toolhead, comparing the distance of the multiple points along the actual axis from the true axis to determine offset amounts from the true axis corresponding to a lack of straightness, and modifying g-code instructions to compensate for the offset amounts before uploading the g-codes to a CNC controller.

A servomotor control device includes: a servomotor; a driven body that is driven by way of the servomotor; a connection mechanism that connects the servomotor and the driven body to transmit power of the servomotor to the driven body; and a motor control unit that controls the servomotor, in which the motor control unit includes: a force acquisition section that acquires a drive force acting on the driven body at a connection part between the connection mechanism and the driven body; and a rigidity estimation section that estimates a magnitude of rigidity of the connection mechanism, based on position information of the servomotor and a drive force acquired by the force acquisition section when causing the servomotor to rotate in a state mechanically fixing the driven body.

A method for controlling a machine tool in which a main spindle on which a tool is mounted and a table holding a workpiece are moved relative to each other by two or more translation axes that are not perpendicular to each other and at least one rotation axis. In the method, an error in a position of the tool with respect to the workpiece due to a geometric error is corrected to calculate a command value for controlling the translation axis. The method includes a conversion step of converting the error and a correction value for correcting the error by performing a homogeneous coordinate transformation from a workpiece coordinate system to the imaginary Cartesian coordinate system, and a correction value calculation step of calculating a correction value in a command value coordinate system of the translation axis by performing a homogeneous coordinate transformation of the correction value.

The present invention relates to an apparatus and to a method for compensation of errors of a numerically controlled machine tool, which has at least one controllable machine axis for relative positioning of at least one workpiece relative to one or more machining devices. The method comprises detecting actual measured values of at least one input variable describing a state of the machine tool by means of sensors on the machine tool, providing at least one compensation parameter to be utilized by a control device of the machine tool on the control device of the machine tool and compensating errors on the machine tool on the basis of the compensation parameter provided to the control device. The compensation comprises the compensation of thermal errors, the compensation of geometric errors and the compensation of errors on the basis of the dynamics of the machine.