Die cushion control device, die cushion control method, and storage medium

A die cushion control method to control a die cushion mechanism to generate pressure or force against a slide of a press using a servomotor as a drive source, the die cushion control method comprising:

• outputting a first pressure command that is a command on the pressure or the force to be generated between the die cushion mechanism and the slide;
• detecting information on the pressure or the force generated between the die cushion mechanism and the slide as a detected pressure;
• predicting a pressure deviation that is a difference between the pressure or the force in the first pressure command and the detected pressure caused when the die cushion mechanism is controlled according to the first pressure command, based on translational acceleration of the slide, control parameters used when the pressure or the force of the die cushion mechanism is controlled, and a die cushion travel amount per revolution of the servomotor, and outputting the predicted pressure deviation as a correction pressure command;
• correcting the first pressure command with the correction pressure command to calculate a second pressure command;
• and
• calculating a speed command to cause the detected pressure to follow the second pressure command to output a drive current corresponding to the speed command to the servomotor.

A non-transitory computer readable storage medium storing a die cushion control program to control a die cushion mechanism to generate pressure or force against a slide of a press using a servomotor as a drive source,

• the die cushion control program causing a computer to perform:
• outputting a first pressure command that is a command on the pressure or the force to be generated between the die cushion mechanism and the slide;
• detecting information on the pressure or the force generated between the die cushion mechanism and the slide as a detected pressure;
• predicting a pressure deviation that is a difference between the pressure or the force in the first pressure command and the detected pressure caused when the die cushion mechanism is controlled according to the first pressure command, based on translational acceleration of the slide, control parameters used when the pressure or the force of the die cushion mechanism is controlled, and a die cushion travel amount per revolution of the servomotor, and outputting the predicted pressure deviation as a correction pressure command;
• correcting the first pressure command with the correction pressure command to calculate a second pressure command;
• and
• calculating a speed command to cause the detected pressure to follow the second pressure command to output a drive current corresponding to the speed command to the servomotor.