Servo control device

A servo control method for calculating a drive command that causes a feedback position from a motor to follow a command position, to drive the motor according to the drive command, wherein

• the servo control method comprises:
• outputting a determination result as a moving state, the determination result being obtained by determining as to which of positive, negative, or zero a speed of the motor is by simulating a response of the motor;
• selecting a correction amount according to a change pattern of the moving state at a timing when the determined moving state changes;
• and
• generating a corrected drive command by adding the correction amount to the calculated drive command, and setting the corrected drive command as a drive command to the motor instead of the calculated drive command, and wherein
• the outputting includes, storing a moving state immediately before the moving state changes to speed zero, at a point in time when the moving state has changed from a state other than speed zero to speed zero, and outputting the stored moving state immediately before the moving state changes to speed zero as the moving state immediately before speed zero, and
• the selecting includes
• outputting a correction amount corresponding to each of a case where the moving state has changed from positive to negative and a case where the moving state has changed from negative to positive, respectively, and
• in a case where the moving state has changed from speed zero to a state other than speed zero, and the moving state immediately before the speed zero and the moving state after a change are different from each other, outputting a correction amount corresponding to the case.

A servo control device comprising:

• processing circuitry configured to:
• calculate a drive command that causes a feedback position from a motor to be driven to follow a command position, to drive the motor according to the drive command,
• determine as to which of positive, negative, or zero a speed of the motor is by simulating a response of the motor, and output a determination result as a moving state,
• select a correction amount according to a change pattern of the moving state at a timing when the determined moving state changes and the motor is temporarily stopped, and
• add the correction amount to the drive command calculated to generate a corrected drive command, and set the corrected drive command as a drive command to the motor instead of the drive command calculated;
• and
• the servo control device further comprising a memory that stores a moving state immediately before the moving state changes to speed zero, at a point in time when the moving state has changed from a state other than speed zero to speed zero, and wherein
• the processing circuitry is further configured to:
• output the stored moving state immediately before the moving state changes to speed zero as the moving state immediately before speed zero,
• output a correction amount corresponding to each of a case where the moving state has changed from positive to negative and a case where the moving state has changed from negative to positive, respectively, and
• in a case where the moving state has changed from speed zero to a state other than speed zero, and the moving state immediately before the speed zero and the moving state after a change are different from each other, output a correction amount corresponding to the case.