A new position control apparatus is provided which can reduce deviation caused by a non-linear spring characteristic of a rolling apparatus. In a position control apparatus (5) that controls the position of a movable body (1), in a positioning apparatus (9) including a rolling apparatus (2), a deviation e(t) or d of the movable body 1 caused by the non-linear spring characteristic of the rolling apparatus (2) is subtracted from or added to a position command Xref or r of the movable body (1). The deviation d is calculated by carrying out equivalent exchange on a control circuit for a friction force of the rolling apparatus (2), which is set as a quantity of the dimension of displacement.

The numerical control system includes: detecting circuitry to obtain cutting force generated in a machine tool; controlling circuitry to calculate a control amount according to a cutting condition and to control a feed drive mechanism of the machine tool; countermeasure determining circuitry to, when it is detected from the cutting force or a state of the feed drive mechanism of the machine tool that a machining defect has occurred, calculate a plurality of deviation degrees for possible causes of the machining defect, and compare the calculated deviation degrees and to thereby determine a cause of the machining defect whose occurrence has been detected; and correction-amount calculating circuitry to calculate, according to the cause of the machining defect determined by the countermeasure determining circuitry, a correction amount with respect to the control amount, and then output the correction amount to the controlling circuitry.

A numerical control device includes: a tool-side displacement measurement unit; a workpiece-side displacement measurement unit; a drive signal measurement unit; a relative displacement calculation unit between the tool and the workpiece; a relative displacement prediction unit calculating a relative displacement predicted value from the drive signal, from a prediction model representing a relationship between the drive signal and the relative displacement; a model parameter operation unit generating prediction model parameters constituting the prediction model, from the drive signal, the relative displacement, and the predicted value; and a command value correction unit outputting a post-correction position command obtained by correcting a position command to the drive unit using the prediction model parameters. The model parameter operation unit changes the prediction model parameters to reduce a difference between the relative displacement and the predicted value.

A control device, a control program and a control system are provided. The control device includes: a first identification device for giving a first command as a command value to a drive device and determining a torque required for the controlled object to execute the first command; a second identification device for giving a second command as the command value and a third command as a compensation command to the drive device and determining a preceding switching time based on a response from the controlled object; a command value updating device for sequentially updating the command value based on a predetermined target trajectory; and a compensation command updating device for sequentially updating the compensation command based on the command value. The compensation command updating device updates the compensation command according to a moving direction after a reversal of the moving direction of the controlled object in the target trajectory.

A numerical control device includes: a tool-side displacement measurement unit; a workpiece-side displacement measurement unit; a drive signal measurement unit; a relative displacement calculation unit between the tool and the workpiece; a relative displacement prediction unit calculating a relative displacement predicted value from the drive signal, from a prediction model representing a relationship between the drive signal and the relative displacement; a model parameter operation unit generating prediction model parameters constituting the prediction model, from the drive signal, the relative displacement, and the predicted value; and a command value correction unit outputting a post-correction position command obtained by correcting a position command to the drive unit using the prediction model parameters. The model parameter operation unit changes the prediction model parameters to reduce a difference between the relative displacement and the predicted value.

A controller that performs, for one or more axes of a machine, position control by taking friction into consideration includes a data acquisition unit acquiring at least a position command and a position feedback and a compensation torque estimation unit estimating coefficients of a friction model used when the position control is performed, on the basis of a position deviation which is a difference between the position command and the position feedback.

A numerically controlled machine tool in which a numerical control program acquired from a reading and interpreting unit of a numerical control device is executed by a distribution interpolating unit and servo control units, to drive a feed shaft configured from a coarse movement mechanism and a fine movement mechanism, causing a tool to move relative to a workpiece, and thereby machining the workpiece, wherein the difference between a movement command for the feed shaft, and an output value which varies on the basis of said movement command is obtained, a movement command for the coarse movement mechanism is generated on the basis of said movement command, and a movement command for the fine movement mechanism is generated on the basis of said difference.

The invention concerns a method for controlling a mechanism (10) displaying asymmetrical behaviour, the mechanism (10) comprising a first operating direction (F+) and a second operating direction (F?), the control method making it possible to generate, using a control module (24) of a computer (20), a control signal (x_com) from a setpoint signal (x_cons), in whichwhen the setpoint signal (x_cons) indicates that the mechanism (10) should be operated in the first direction (F+), the control module (24) applies a first corrector (100) to the setpoint signal (x_cons) in order to generate a control signal (x_com),when the setpoint signal (x_cons) indicates that the mechanism (10) should be operated in the second direction (F?), the control module (24) applies a second corrector (100) to the setpoint signal (x_cons) in order to generate a control signal (x_com), and in which the first and second correctors (100, 200) have different parameters (Kp1, Kp2, Ti1, Ti2), in order to compensate for the asymmetrical behaviour of the mechanism (10).

An abnormality diagnosis apparatus includes: a friction identification unit that calculates a friction parameter that is a parameter used for calculation of frictional force of a power transmission mechanism connected to a motor; a model torque calculation unit that calculates model torque by performing a process of calculating an estimated value of torque of the motor by using a set value calculated in advance and the friction parameter; and an abnormality determination unit that diagnoses whether the power transmission mechanism is abnormal, on the basis of a result of comparison between the model torque and a motor torque detected by a motor torque detection unit.

A friction identification method includes: measuring a relation between a driving force and a position of a driven object; identifying a parameter of a position-dependent friction model based on a relation between a driving force and a position of the driven object; measuring a relation between a driving force and a displacement of the driven object from a position at which a motion direction is reversed; identifying a parameter of a displacement-dependent friction model; measuring a relation between a driving force and a velocity of the driven object; identifying a parameter of a velocity-dependent friction model; measuring a relation between a driving force and an acceleration of the driven object; and identifying a parameter of an acceleration-dependent friction model.