Macro-micro Driven Ultra-Precision Positioning Stage for Conventional Grinder

Precision positioning stage is the key part of precision feed system of a machine. To compensate for the effect of processing precision affected by the vibration of wheelhead of precision grinder, a micro-feed worktable using piezoelectric actuators, which serves as an auxiliary feeding device, has been introduced for common cylindrical grinders. The stiffness of its support-oriented mechanism is modeled and analyzed by PRO/E and FEA. A close-loop control system based on special algorithm is presented and the prototype of a macro-micro driven ultra-precision positioning stage on grinder is developed. The experimental results show that the positioning accuracy of the stage is 0.1 +/- 0.02 mu m, its average stiffness is 207 N/mu m and the cylindricity of machined parts is less than 2 mu m.