A numerical control device for a machine tool controls a machine tool having a main spindle for attaching a tool, a table holding a workpiece and a jig, three translational axes, and one or more rotation axis. The numerical control device includes an axis-dependent deformation error estimation unit, an input unit, a gravitational deformation estimation unit, a correction value calculation unit, and an addition unit. The correction value calculation unit calculates a correction value of the translational axes and/or the rotation axis with respect to an error of a position and/or a posture of the tool with respect to the workpiece, based on an estimated value of an axis-dependent deformation error, an estimated value of a gravitational deformation error, and command values. The addition unit adds the correction values to the command values.

A method for calibrating a machining system includes providing the machining system which includes a base, a cantilevered arm, and a rotary table positioned at the second arm end of the cantilevered arm. The rotary table is rotatable relative to the cantilevered arm about a first axis. The first axis has a first unloaded position and a first unloaded orientation with the machining system in an unloaded condition. The method further includes installing a measurement artifact on the rotary table, measuring a first position of the measurement artifact, and installing a load on the rotary table. The first axis has a first loaded position and a first loaded orientation with the machining system in a loaded condition. The method further includes measuring a second position of the measurement artifact and determining a positional deviation of the second position from the first position.

An angular transmission error identification system that identifies an angular transmission error of a speed reducer of a robot arm including a joint that is rotationally driven by a motor via the speed reducer, including an identification unit that calculates amplitude and phase parameters of an angular transmission error identification function, which is a periodic function that models an angular transmission error of the speed reducer and has the parameters, and identifies the error using the function, wherein the unit calculates an amplitude parameter corresponding to a gravitational torque current value which is a value acting on a joint when the error is identified using a first or second amplitude function according to a value of the gravitational torque current value, and calculates a phase parameter corresponding to the gravitational torque current value using a first or second phase function according to a value of the gravitational torque current value.

An angular transmission error identification system that identifies an angular transmission error of a speed reducer of a robot arm including a joint that is rotationally driven by a motor via the speed reducer, including an identification unit that calculates amplitude and phase parameters of an angular transmission error identification function, which is a periodic function that models an angular transmission error of the speed reducer and has the parameters, and identifies the error using the function, wherein the unit calculates an amplitude parameter corresponding to a gravitational torque current value which is a value acting on a joint when the error is identified using a first or second amplitude function according to a value of the gravitational torque current value, and calculates a phase parameter corresponding to the gravitational torque current value using a first or second phase function according to a value of the gravitational torque current value.

A robot arm apparatus is provided and includes: an arm unit made up of a plurality of links joined to each other by one or a plurality of a joint unit; and a driving control unit that drives the arm unit by controlling driving of the joint unit. If a malfunction is detected in at least one of the joint unit, the driving control unit controls the driving of the joint unit in a state in which a certain restriction is imposed on motion of the arm unit, and drives the arm unit to avoid the malfunction.

A machining tool with a numerical control device includes an actual gravity center calculation unit configured to calculate an actual gravity center, the actual gravity center being a whole gravity center of the machining tool and the load, a target gravity center position set unit, a movable part position correction unit configured to correct the relative position of the movable part to the fixed part, to make the target gravity center position and the whole center gravity center position of the machining tool and the load coincident.

A robot arm apparatus is provided and includes: an arm unit made up of a plurality of links joined to each other by one or a plurality of a joint unit; and a driving control unit that drives the arm unit by controlling driving of the joint unit. If a malfunction is detected in at least one of the joint unit, the driving control unit controls the driving of the joint unit in a state in which a certain restriction is imposed on motion of the arm unit, and drives the arm unit to avoid the malfunction.

A medical support arm apparatus including: an arm unit including a plurality of links joined to each other by one or a plurality of a joint unit; and a driving control unit that drives the arm unit by controlling driving of the joint unit. If a malfunction is detected in at least one of the joint unit, the driving control unit controls the driving of the joint unit in a state in which a certain restriction is imposed on motion of the arm unit, and drives the arm unit to avoid the malfunction.

A numerical control device for a machine tool controls a machine tool having a main spindle for attaching a tool, a table holding a workpiece and a jig, three translational axes, and one or more rotation axis. The numerical control device includes an axis-dependent deformation error estimation unit, an input unit, a gravitational deformation estimation unit, a correction value calculation unit, and an addition unit. The correction value calculation unit calculates a correction value of the translational axes and/or the rotation axis with respect to an error of a position and/or a posture of the tool with respect to the workpiece, based on an estimated value of an axis-dependent deformation error, an estimated value of a gravitational deformation error, and command values. The addition unit adds the correction values to the command values.

A system and method for maneuvering a robotic end-effector using one or more motors that have a force limiter that is adaptable to take into account any effects of a changing gravitational force as the system moves. In one embodiment, the system includes an actuator, such as a drive motor, for applying a force vector to actuate a function of the end effector, such as moving the end-effector along a track that is attached to a contoured surface. Further, a force limiter coupled to the actuator is configured to interrupt the actuating if the force exceeds a first threshold. Further, the system includes an orientation detector to determine any changes in orientation with respect to gravity so as to adjust the force limit accordingly. Thus, if the force limiter determines that a threshold has been exceeded, the force limiter may limit or interrupt the motion while taking changing gravitational forces into account.