This disclosure provides a machine tool adjustment method and system thereof. The machine tool adjustment method includes the following steps: enabling a machine tool to perform a circular test; obtaining a measured error value E.sub.m from a measuring instrument, and the measured error value E.sub.m is defined by the difference between the actual circular trajectory and the preset circular trajectory during the circular test; determining an error condition of the tool machine from the measured error value E.sub.m; determining whether the error condition is less than a predetermined criteria; if not, defining a compensation parameter according to the error condition and enabling the machine tool to perform another circular test according to the set compensation parameter until the error condition is less than the predetermined criteria; and if yes, ending the circular test and the machine tool adjustment is finished.

Stop and start detection block (63) determines whether or not a joint portion is in a stopped state before a rotation direction of the joint portion is inverted based on stop flag signal (Stop_Flg). When it is determined that the joint portion is in the stopped state, filter processing block (65) changes a frequency component of a correction amount for correcting backlash to a low frequency lower than a predetermined threshold value.

In an angular velocity calculation block, an angular velocity component is calculated based on a position command for a joint portion. In a kinetic calculation block, a kinetic torque is calculated based on the position command for the joint portion. In a command velocity component reversal detection block, a reversal timing is calculated based on the angular velocity component. In a reverse torque detection block, a reverse torque is calculated based on the kinetic torque and the reversal timing. In a backlash correction amount calculation block, the correction amount of the joint portion is calculated based on the kinetic torque, the reverse torque, and the reversal timing.

This disclosure provides a machine tool adjustment method and system thereof. The machine tool adjustment method includes the following steps: enabling a machine tool to perform a circular test; obtaining a measured error value E.sub.m from a measuring instrument, and the measured error value E.sub.m is defined by the difference between the actual circular trajectory and the preset circular trajectory during the circular test; determining an error condition of the tool machine from the measured error value E.sub.m; determining whether the error condition is less than a predetermined criteria; if not, defining a compensation parameter according to the error condition and enabling the machine tool to perform another circular test according to the set compensation parameter until the error condition is less than the predetermined criteria; and if yes, ending the circular test and the machine tool adjustment is finished.

In an angular velocity calculation block, an angular velocity component is calculated based on a position command for a joint portion. In a kinetic calculation block, a kinetic torque is calculated based on the position command for the joint portion. In a command velocity component reversal detection block, a reversal timing is calculated based on the angular velocity component. In a reverse torque detection block, a reverse torque is calculated based on the kinetic torque and the reversal timing. In a backlash correction amount calculation block, the correction amount of the joint portion is calculated based on the kinetic torque, the reverse torque, and the reversal timing.

A servo motor controller for performing more precise machining by calculating an appropriate compensation amount for a servo motor even in the case where the servo motor performs a reversal or the like. The controller includes a command calculation part for calculating a command for a position or a speed of a servo motor, a determining part for determining that the servo motor is performing reversal or movement from stop, an acceleration calculation part for obtaining the acceleration of the servo motor based on the determination result, and a compensation amount calculation part for calculating a compensation amount for compensation of delay of the servo motor. The acceleration calculation part obtains the acceleration even after the servo motor performs reversal or movement from stop. The compensation amount calculation part calculates the compensation amount according to the obtained acceleration, even after the servo motor performs reversal or movement from stop.

Stop and start detection block (63) determines whether or not a joint portion is in a stopped state before a rotation direction of the joint portion is inverted based on stop flag signal (Stop_Flg). When it is determined that the joint portion is in the stopped state, filter processing block (65) changes a frequency component of a correction amount for correcting backlash to a low frequency lower than a predetermined threshold value.

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.