Machining technology for non-axisymmetric optical surfaces

Piezoelectric fast tool servo mechanism, with its existing nonlinear response and hysteresis, restricts greatly the precision when applied to machining of non-axisymmetric optical surface. In this paper, a feed-forward control method is applied to compensate the displacement of the fast tool servo. According to the workpiece surface feature and the tool path, the mathematical model of the minimum setting angle is established to avoid the interference between the tool and the surface to be machined. A new kind of control method - real time calculating control with table look-up is developed. This control method can shorten the calculating time and improve the precision of the machining surface at the same time.