Okuma Corporation | Date: 2016-01-11
A thermal displacement correcting apparatus includes a correction amount estimating device and a parameter automatic selecting device that, in a machine tool having two different sets of specifications that differ due to the presence/absence of a scale and different methods of measuring the lengths of a bed and a table, estimate a thermal displacement correction amount of the machine tool of each set of specifications. The two devices store a collection of parameters for an estimated thermal displacement calculation corresponding to each of the bed, the scale, the table, and a workpiece, as a database, and select the parameters belonging to the set of specifications from the database based on machine information according to each set of specifications, calculate estimated thermal displacements of the bed, the table, and the workpiece, or also the scale, according to the selected parameters, and combine the estimated thermal displacements.
OKUMA Corporation | Date: 2015-07-10
To provide a linear encoder including a scale unit and a slider that slides along the scale unit, wherein the slider includes a slider enclosure including a slider holding unit, a detection head holding unit mounted inside a scale enclosure of the scale unit, and a pillar extending between the outside and inside of the scale enclosure to connect these two holding units, and a part of the pillar closer to the detection head holding unit and a part of the detection head holding unit closer to the pillar are bored by a thickness larger than a thickness of the pillar.
OKUMA Corporation | Date: 2015-09-22
A hydraulic pressure control device comprising: a hydraulic sensor provided between a hydraulic pump and a load; a speed command arithmetic unit configured to output a speed command value Vc based on a difference between a hydraulic pressure detection value Pd from the hydraulic sensor and a hydraulic pressure command value Pc; a torque command value arithmetic unit configured to calculate a torque command value Tc based on a difference between a speed detection value Vd of a motor and the speed command value Vc; a current controller configured to control current of the motor based on the torque command value Tc; and a hydraulic pressure abnormality detector configured to detect whether a hydraulic circuit has abnormality based on the speed command value Vc and an operating condition of the load of the hydraulic circuit commanded from an upper-level control device.
OKUMA Corporation | Date: 2015-08-19
A tandem control method is applied to a position control apparatus. The tandem control method controls one object to be controlled by individually driving a first driving shaft and a second driving shaft. A speed difference between the first driving shaft and the object to be controlled is amplified and added to a torque command value of the first driving shaft. A speed difference between the second driving shaft and the object to be controlled is amplified and added to a torque command value of the second driving shaft.
OKUMA Corporation | Date: 2015-09-01
A disturbance suppressing system is incorporated in a servo control apparatus. In the disturbance suppressing system, a component e introduced in an output of a target plant due to a disturbance estimate error is amplified in a disturbance suppressing controller having a frequency characteristic corresponding to a magnitude of a plant error, which is a difference in transfer characteristics between the target plant and the plant model, and the amplified component e is fed back to a control input.