Servo motor control device for controlling servo motor configured to drive feed axis of machine tool
First Claim
1. A servo motor control device for carrying out feedback control to a servo motor configured to drive a feed axis of a machine tool in order to carry out:
 a cuttingfeed to move the feed axis of the machine tool while cutting a workpiece if an operating command in a machining program to machine the workpiece using the machine tool is a cuttingfeed command; and
a rapidtraverse operation to move the feed axis of the machine tool without cutting a workpiece if the operating command in the machining program to machine the workpiece using the machine tool is a rapidtraverse operation command, comprising;
an arithmetic coefficient setting unit configured to set a feedback control arithmetic coefficient to a value between a first feedback control arithmetic coefficient value for the cuttingfeed and a second feedback control arithmetic coefficient value for the rapidtraverse operation smaller than the first feedback control arithmetic coefficient value;
an arithmetic coefficient change unit configured to continuously change the feedback control arithmetic coefficient from the second feedback control arithmetic coefficient value to the first feedback control arithmetic coefficient value over a first period between a first time, which is an arbitrary time during the rapidtraverse operation, and a second time after the first time or a second period between a third time after the first time and before the second time, and the second time if it is predicted at the first time that the operating command will switch from the rapidtraverse operation command to the cuttingfeed command at the second time; and
a torque command generation unit configured to generate a torque command to the servo motor based on at least one of a position command to the servo motor and a velocity command to the servo motor, at least one of a position error of the servo motor and a velocity error of the servo motor, and the feedback control arithmetic coefficient.
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Accused Products
Abstract
An arithmetic coefficient setting unit sets a feedback control arithmetic coefficient to a value between a first feedback control arithmetic coefficient value for a cuttingfeed and a second feedback control arithmetic coefficient value for a rapidtraverse operation smaller than the first feedback control arithmetic coefficient value. An arithmetic coefficient change unit continuously changes the feedback control arithmetic coefficient from the second feedback control arithmetic coefficient value to the first feedback control arithmetic coefficient value over a first period between a first time, which is an arbitrary time during the rapidtraverse operation, and the second time after the first time or a second period between a third time after the first time and before the second time, and the second time if it is predicted at the first time that the operating command switches from the rapidtraverse operation command to the cuttingfeed command at the second time.
5 Citations
8 Claims

1. A servo motor control device for carrying out feedback control to a servo motor configured to drive a feed axis of a machine tool in order to carry out:
 a cuttingfeed to move the feed axis of the machine tool while cutting a workpiece if an operating command in a machining program to machine the workpiece using the machine tool is a cuttingfeed command; and
a rapidtraverse operation to move the feed axis of the machine tool without cutting a workpiece if the operating command in the machining program to machine the workpiece using the machine tool is a rapidtraverse operation command, comprising;an arithmetic coefficient setting unit configured to set a feedback control arithmetic coefficient to a value between a first feedback control arithmetic coefficient value for the cuttingfeed and a second feedback control arithmetic coefficient value for the rapidtraverse operation smaller than the first feedback control arithmetic coefficient value; an arithmetic coefficient change unit configured to continuously change the feedback control arithmetic coefficient from the second feedback control arithmetic coefficient value to the first feedback control arithmetic coefficient value over a first period between a first time, which is an arbitrary time during the rapidtraverse operation, and a second time after the first time or a second period between a third time after the first time and before the second time, and the second time if it is predicted at the first time that the operating command will switch from the rapidtraverse operation command to the cuttingfeed command at the second time; and a torque command generation unit configured to generate a torque command to the servo motor based on at least one of a position command to the servo motor and a velocity command to the servo motor, at least one of a position error of the servo motor and a velocity error of the servo motor, and the feedback control arithmetic coefficient.  View Dependent Claims (2, 3, 4, 5, 6, 7)
 a cuttingfeed to move the feed axis of the machine tool while cutting a workpiece if an operating command in a machining program to machine the workpiece using the machine tool is a cuttingfeed command; and

8. A servo motor control device for carrying out feedforward control and feedback control for a servo motor configured to drive a feed axis of a machine tool in order to carry out:
 a cuttingfeed to move the feed axis of the machine tool while cutting a workpiece if an operating command in a machining program to machine the workpiece using the machine tool is a cuttingfeed command; and
a rapidtraverse operation to move the feed axis of the machine tool without cutting a workpiece if the operating command of the machining program in a machining program to machine the workpiece using the machine tool is a rapidtraverse operation command, comprising;an arithmetic coefficient setting unit configured to set a feedforward control arithmetic coefficient to a value between a first feedforward control arithmetic coefficient value for the cuttingfeed and a second feedforward control arithmetic coefficient value for the rapidtraverse operation smaller than the first feedforward control arithmetic coefficient value; an arithmetic coefficient change unit configured to continuously change the feedforward control arithmetic coefficient from the second feedforward control arithmetic coefficient value to the first feedforward control arithmetic coefficient value over a first period between a first time, which is an arbitrary time during the rapidtraverse operation, and a second time after the first time or a second period between a third time after the first time and before the second time, and the second time if it is predicted at the first time that the operating command will switch from the rapidtraverse operation command to the cuttingfeed command at the second time; and a torque generation unit configured to generate a torque command to the servo motor based on at least one of a position command to the servo motor and a velocity command to the servo motor and the feedforward control arithmetic coefficient.
 a cuttingfeed to move the feed axis of the machine tool while cutting a workpiece if an operating command in a machining program to machine the workpiece using the machine tool is a cuttingfeed command; and
1 Specification