Research of high-speed precision positioning system based on double-frequency laser interference

In order to realize fast driving and positioning for a wide-range and high precision measurement system, a precision positioning system with good repeatability is developed combining double-frequency laser interference, aerostatic guideway with pipeline channeling off used air, precision ball-screw and servo control system. The system uses laser interference as length measuring standard, location information of the workbench is fed back by double-frequency laser interference in real time. Using aerostatic guideway with pipeline channeling off used air overcomes the residual air influence on laser interference measurement optical path system in traditional gas float guideway. PID control technology is applied in the process of positioning, the system has fast and smooth response characteristics by adjusting PI parameters of the servo controller. Experiments show that, in the range of 500mm, bidirectional accuracy of positioning of the system is 0.266 μm, and the repeatability is 0.173 μm, it has quick response. The scanning experiment of one dimensional linear grating sample is compared with the scanning result of Olympus confocal microscope, the result shows that it has a good ability in axial positioning.