Numerical control apparatus
Patent 4890046 Issued on December 26, 1989. Estimated Expiration Date: 
July 29, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 29, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3886424 Motorized ball nut Position control apparatus and method Method and device for correcting backlash Patent #: 4743823 InventorsAssigneeApplicationNo. 231853 filed on 07/29/1988US 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 systemsExaminersPrimary: Shoop, William M. Jr.Assistant: Bergmann, Saul M. Attorney, Agent or FirmInternational ClassG05B 011/01Foreign Application Priority Data1986-12-12 JPAbstractA 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). | |
