SERVOMOTOR DRIVE CONTROL DEVICE

Japanese Patent JP3805309

B2

PROBLEM TO BE SOLVED: To prevent quadrant projection from being generated which is to be generated at the time of changing the quadrant of processing position and moving direction of a feeding shaft is reversed, and enable high precision processing. SOLUTION: In a stage of positional deviation focusing to zero by learning control, a speed command or difference of the speed command and a command speed which is calculated by deviating a position command is provided as speed correction data. These correction data are stored in a speed offset means 4. Position deviation is calculated from position command and speed feedback and multiplied by position gain Kp to calculate speed command. After detecting reverse of negative sign of the position command, for a predetermined period of time, correction of the speed command is started. Based on the speed correction data stored in the speed offset means 4, correction quantity corresponding to each position loop process cycle is calculated and the correction quantity is added to the speed command and provided as corrected speed command Vc. As the speed command is corrected based on the speed correction data, the quadrant projection generated at the position where the quadrant change becomes small and high precision processing becomes possible.