A time necessary for phase alignment is shortened in a polygon machining device having a plurality of cutting tools. In phase alignment of polygon machining, a phase R.sub.CURRENT of the workpiece axis and tool axis before phase alignment and a machining-allowing phase command value R.sub.NEW(n) are calculated, a new phase command value R′.sub.NEW is calculated while considering restrictions such as a phase alignment method and a maximum rotation speed. By adjusting a phase to the new phase command value R′.sub.NEW, a time necessary for phase alignment can be shortened.

An operation control method and system for a clothing treatment device having a drum and a motor is provided. Load inertia of the drum and a fluctuation parameter of the motor are obtained. Load eccentric mass of the clothing treatment device is obtained based on the load inertia, the fluctuation parameter, and predetermined relationship data that is obtained based on pre-stored load inertia, torque fluctuation and load eccentric mass. The fluctuation parameter can be a torque fluctuation parameter or a rotation speed fluctuation parameter. The clothing treatment device can be controlled according to the load eccentric mass to optimize washing operations. For example, clothing and/or inlet water amount can be timely adjusted according to the calculated load eccentric mass. Thus, the clothing treatment device is prevented from producing significant noise during operations, and the service life of the clothing treatment device can be prolonged.

A machine tool capable of facilitating the setting of the vibration cutting conditions. A control unit acquires a feed speed of a object to be fed without a vibration (Fa), a number of rotations of a spindle required for a single cycle of the vibration (K), and a returning amount (R) representing a distance of a returning feed per the single cycle of the vibration. According to the acquired parameters, the control unit decides at least one parameter among a cutting amount (D) representing a distance of a change in a position of the object per the single cycle of the vibration, a cutting feed speed (F) of the object, and a returning feed speed (B) of the object. The control unit controls the position of the object to be fed with the vibration at least according to the decided parameter.

A main spindle controller of a machine tool varies a rotation speed of a main spindle that grips a workpiece to a varied maximum speed higher than a reference rotation speed set value as a set value of a reference rotation speed by a variation width set value as a set value of a variation width or a varied minimum speed lower than the reference rotation speed set value by the variation width set value in units of the tool path. At the same time, the main spindle controller refers to speed condition information that indicates a condition of the preliminarily stored reference rotation speed and variation width assuming that a chatter vibration is to be reduced, and when at least one of the reference rotation speed set value and the variation width set value does not satisfy the condition of the speed condition information.

A robot-supported grinding method is described. In accordance with one example of the invention, the grinding method includes contacting a surface of a workpiece with a rotating grinding tool, whereby either the grinding tool or the workpiece is mechanically coupled to the tool center point (TCP) of a manipulator. The method further includes controlling an actuator that influences the grinding tool or the workpiece to produce a grinding force between the grinding tool and the workpiece, as well as measuring an actual deflection of the actuator. The rotational velocity of the grinding tool is adjusted depending on the measured actual deflection of the actuator and a reference deflection of the actuator.

A time necessary for phase alignment is shortened in a polygon machining device having a plurality of cutting tools. In phase alignment of polygon machining, a phase R.sub.CURRENT of the workpiece axis and tool axis before phase alignment and a machining-allowing phase command value R.sub.NEW(n) are calculated, a new phase command value R.sub.NEW is calculated while considering restrictions such as a phase alignment method and a maximum rotation speed. By adjusting a phase to the new phase command value R.sub.NEW, a time necessary for phase alignment can be shortened.

An operation control method and system for a clothing treatment device having a drum and a motor is provided. Load inertia of the drum and a fluctuation parameter of the motor are obtained. Load eccentric mass of the clothing treatment device is obtained based on the load inertia, the fluctuation parameter, and predetermined relationship data that is obtained based on pre-stored load inertia, torque fluctuation and load eccentric mass. The fluctuation parameter can be a torque fluctuation parameter or a rotation speed fluctuation parameter. The clothing treatment device can be controlled according to the load eccentric mass to optimize washing operations. For example, clothing and/or inlet water amount can be timely adjusted according to the calculated load eccentric mass. Thus, the clothing treatment device is prevented from producing significant noise during operations, and the service life of the clothing treatment device can be prolonged.

A main spindle controller of a machine tool varies a rotation speed of a main spindle that grips a workpiece to a varied maximum speed higher than a reference rotation speed set value as a set value of a reference rotation speed by a variation width set value as a set value of a variation width or a varied minimum speed lower than the reference rotation speed set value by the variation width set value in units of the tool path. At the same time, the main spindle controller refers to speed condition information that indicates a condition of the preliminarily stored reference rotation speed and variation width assuming that a chatter vibration is to be reduced, and when at least one of the reference rotation speed set value and the variation width set value does not satisfy the condition of the speed condition information.