Numerical controller

Abstract

When a servomotor (control axis) e.g. in a die-casting machine is coasting and rotating in a servo-off state in which no current is applied to the servomotor, this servo-off state is switched over to a servo-on state in which current is applied to the servomotor, and a position control and a speed control are started. An actual speed in servo-on state is obtained in speed obtaining means by a position / speed detector. Position command means obtains a command movement amount using the actual speed as an initial speed. A position deviation amount corresponding to the actual speed is calculated, a command movement amount, a position deviation amount, and a position deviation amount remaining in a position deviation counter in servo-on state with the sign thereof reversed are added to each other as a command amount to the position deviation counter.

Description

technical field [0001] The present invention relates to a numerical control device for position control of a servo motor or a control shaft driven and controlled by a servo motor, and more particularly to a servo motor (movable part) inertia During operation, a numerical control device that flows current into the servo motor to start position control. Background technique [0002] In a numerical controller that drives a control shaft such as a movable part of a machine using a servo motor and controls the position of the control shaft, the position is usually controlled by performing position loop control. [0003] In addition, it is also known that the servo motor is driven and controlled by the control device, the position control is performed before the position of the controlled object reaches the target position, and then when the control device performs control other than the position control of the controlled object, the control The device sets the target position in...

AI Technical Summary

Problems solved by technology

As a result, as shown in Fig. 12, when the position control is started after the servo OFF state is changed to the servo ON state, there is a problem that a sudden speed change such as rapid deceleration and then acceleration occurs, and smooth movement cannot be achieved.

Also, even if the value of the position deviation counter is periodically reset to zero by follow-up processing, the position deviation remains in the position deviation counter due to the timing of servo ON, and the above-mentioned speed change occurs.

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