Numerical control device and numerical control method
AssigneeMitsubishi Electric Corporation
InventorsToshiaki Kimata, Kotaro Nagaoka, Naoki Nakamura
Life of this patent
Estimating the term…
Abstract
To dynamically change the acceleration without trial executions of a machining program, a numerical control device, which controls a motor on the basis of a machining program that specifies a path for a drive target of the motor, includes a changing unit that changes the acceleration of the motor under the control of the motor on the basis of the inertia ratio, the acceleration-deceleration factor that can be externally input, or the current value of the motor.
Claims16
A numerical control device that controls a motor according to a program that specifies a path for a drive target of the motor, the numerical control device comprising:
- an acceleration-deceleration processing unit:
- to perform an acceleration-deceleration process on a velocity at which the drive target is moved on the path on the basis of an acceleration set value at the time point and
- to output a velocity obtained after the acceleration-deceleration process;
- an interpolation unit to calculate a position command per control cycle for the motor so as to drive the motor at the velocity obtained after the acceleration-deceleration process;
- and
- a changing unit:
- to monitor a state quantity related to the motor while the motor is being controlled, and
- to change the acceleration set value on the basis of the state quantity while the motor is being controlled, wherein
- the changing unit:
- acquires an acceleration candidate value on the basis of the state quantity,
- acquires a required distance for reducing a velocity of the drive target from a present value to a velocity at a target position specified in the program by using the acceleration candidate value,
- determines whether it is possible for the drive target to be moved to the target position at the acceleration candidate value on the basis of the required distance and a distance from a present position of the drive target to the target position,
- changes the acceleration set value to the acceleration candidate value when it is determined to be possible for the drive target to be moved to the target position at the acceleration candidate value, and
- leaves the acceleration set value unchanged when it is determined to be impossible for the drive target to be moved to the target position at the acceleration candidate value.
A numerical control method for a numerical control device to control a motor according to a program that specifies a path for a drive target of the motor, the numerical control method comprising:
- performing an acceleration-deceleration process on a velocity at which the drive target is moved on the path on the basis of an acceleration set value at that time point, and outputting a velocity obtained after the acceleration-deceleration process;
- calculating a position command per control cycle for the motor so as for the motor to drive at the velocity obtained after the acceleration-deceleration process;
- monitoring a state quantity related to the motor while the motor is being controlled;
- and
- changing the acceleration set value on the basis of the state quantity while the motor is being controlled, wherein
- the monitoring includes:
- acquiring an acceleration candidate value on the basis of the state quantity,
- acquiring a required distance for reducing a velocity of the drive target from a present value to a velocity at a target position specified in the program by using the acceleration candidate value,
- determining whether it is possible for the drive target to be moved to the target position at the acceleration candidate value on the basis of the required distance and a distance from a present position of the drive target to the target position, and
- changing the acceleration set value to the acceleration candidate value when it is determined to be possible for the drive target to be moved to the target position at the acceleration candidate value, and
- leaving the acceleration set value unchanged when it is determined to be impossible for the drive target to be moved to the target position at the acceleration candidate value.
Dependencies are inferred from the claim text.