A two-dimensional table with long travel and micropositioning

High-precision, long travel two-dimensional tables are widely used in ultra-precision machining, multi-dimensional measuring machine, surface grinder and advanced manufacturing fields. A two-dimensional table with long travel and micro-nano positioning is presented in this paper. The table is controlled by the combination of a computer and a FPGA (Field Programmable Gate Array) device. The moving units are consisted of AC servo motors and piezoelectric ceramics (PZT), which are used to achieve macro and micro-positioning respectively. The positioning accuracy is controlled by diffracting gratings and four-quadrant photoelectric receiver (QPD). Experimental results show that the positioning error of this table is 0.2μm, and the working range is 100 × 100 mm².