A system, method, and computer-readable medium for providing a user interface. The system includes circuitry configured to generate chatter information based on sensor data collected from a machining operation of a machine performed at a previously selected tool speed setting. The chatter information includes a chatter level value and a chatter frequency value. A plurality of different candidate tool speed settings is determined based on the generated chatter frequency value from the machining operation. The circuitry generates the user interface that includes a plurality of different tool speed settings, including the previously selected tool speed setting and the plurality of different candidate tool speed settings for selection by a user. The user interface is configured to indicate the chatter level value for the previously selected.

Using a machine tool, a workpiece is machined while periodically varying the rotational speed of a spindle thereof. Correlation data on correlation between a speed variation rate RVA of the spindle rotational speed, a speed variation period ratio RVF thereof, and vibration of a tool when machining the workpiece while periodically varying the spindle rotational speed is previously obtained. Based on the correlation data, the speed variation rate RVA and the speed variation period ratio RVF are set so that the vibration of the tool and machining accuracy are within their respective allowable ranges, and based on the set speed variation rate RVA and speed variation period ratio RVF, a variation amplitude and a variation period of the spindle rotational speed are determined. The spindle is rotated at the rotational speed varying at the determined amplitude and period with respect to a target rotational speed, thereby machining the workpiece.

A chatter avoidance method and device is provided, including steps of: providing a stable operating condition plot; partially removing a first layer of a workpiece with a predetermined first removal depth according to a safe removal depth of the stable operating condition plot and sensing a chatter caused by the removal operation; if no chatter is sensed, completing the removal operation, otherwise, continuing to partially remove the first layer with a second removal depth less than the predetermined first removal depth; and determining a minimum removal depth according to the removal operation, and removing a last layer of the workpiece with a last removal depth less than or equal to the minimum removal depth, allowing the workpiece to have a target thickness. The disclosure prevents a chatter from continuously occurring without requiring a shut-down and thereby maintains a desired production rate.

A chatter vibration suppressing method includes acquiring a moment of inertia of a rotating body, recording a value indicating the acquired moment of inertia into a machining program, and calculating a variable amplitude and a variable period when a rotation speed of the rotating body is varied in order to suppress chatter vibration from the value indicating the moment of inertia recorded in the machining program and the maximum input power of a motor for rotating the rotating body.

A stick motion correction method which corrects stick motion which occurs at time of reversal of a feed axis of a numerical control machine tool stores a position command to be commanded to a servo motor from an NC program of a numerical control machine tool for each predetermined control period from a current position command to a later position command, calculates a reversal correction command based on the stored position commands, calculates an advancement time for advancing timing of addition of the reversal correction command to a speed or torque command of the motor from reversal timing of the servo motor, based on information obtained from operation of the motor and adds the reversal correction command to the speed or torque command of the servo motor to precisely correct stick motion at a timing advanced from the reversal timing of the servo motor by an exact time.

Provided is a control device for a machine tool capable of reducing adverse effects due to rapid changes in periodic fluctuations in the rotation speed of a main spindle while maintaining an effect of suppressing regenerative self-excited chatter vibration. This control device for a machine tool includes a fluctuation command calculation unit configured to calculate a fluctuation command based on a speed command for a main spindle motor of the machine tool and a fluctuation condition for causing a rotation speed of the main spindle motor to periodically fluctuate, and a speed control unit configured to control the rotation speed of the main spindle motor based on the speed command and the fluctuation command. The fluctuation command calculation unit is configured to calculate, when the fluctuation condition is changed, the fluctuation command in which an amplitude of the rotation speed that periodically fluctuates and/or a frequency of the rotation speed that periodically fluctuates gradually changes.