NUMERICAL CONTROLLER

PURPOSE:To make highly accurate control with a numerical controller by deciding a correcting value by taking into account the accelerating or decelerating method and/or reaching speed immediately before making inverse movement. CONSTITUTION:When a working command from an input means 1 commands inverse movement, an arithmetic means 22 reads out the latched accelerating or decelerating method and reaching speed at the movement commanding block immediately before the inverse movement. The means 22 then finds out the correcting value corresponding to the read-out method and speed from the table of a storing means 2, superimposes the value upon a working command value as a backlash correcting value, and outputs the superimposed value of a servo motor control means 3. The means 3 controls a servo motor 6 in accordance with the output. Therefore, the working accuracy is further improved, because a backlash correcting value which is the most suitable for the accelerating or decelerating method and/or reaching seed immediately before making inversive movement can be obtained.