Precision analysis of a large aperture tiled-gratings device

Gratings tiling refers to assembling serial small-sized sub-gratings, to make them into a single integral large aperture grating by means of mechanical process, which is mainly used for pulse compression in the high-energy laser system. In order to ensure that the parallelism and coplanarity between the sub-gratings meet high requirements of submicron level, the grating tiling device itself needs to achieve a high accuracy to match it. On the basis of introducing one tandem type of grating tiling devices, this paper focuses on the analysis, the calculation of various error sources in the grating tiling device. To simplify the analysis process, we will introduce the concept of D-H link parameter deviations, which could contribute to inducting many different local errors into the category of D-H link parameter deviations. After establishing the system kinematic model, it is necessary to carry out partial differential operation on D-H transformation matrix. Then we can easily derive the expression of mechanism´s end errors in the five-dimensional directions. Through the analysis of the accuracy of the grating tiling device, we can grasp the laws of error propagation, which serves to take effectual measures of compensation or correction, so as to improve system accuracy to a further higher level.