ApplicationNo. 231853 filed on 07/29/1988
US Classes:318/630, Antibacklash systems (e.g., with unidirectional approach to balance)318/561, Adaptive or optimizing systems including "bang-bang" servos318/600, Digital or numerical systems318/661Resolver systems
ExaminersPrimary: Shoop, William M. Jr.
Assistant: Bergmann, Saul M.
Attorney, Agent or Firm
International ClassG05B 011/01
Foreign Application Priority Data1986-12-12 JP
AbstractA numerical control apparatus according to the invention reliably eliminates the influence on positional accuracy of static resistance and dynamic resistance, which act as disturbance upon a servo loop, when a semi-closed loop forms a servo system for positioning, by numerical control, a machine tool or the like driven by a servomotor. The numerical control apparatus has a backlash correction function and supplies the servo system with a backlash correction data BL(i) distinguished from an ordinary move command BL(i). In order to eliminate a shift from a commanded position due to the aforementioned disturbance, an offset command corresponding to frictional torque Fa in the mechanical system of the machine tool or the like is applied to the servo system as a torque correction signal FR(i) in accordance with the backlash correction data BL(i).