Abstract: Micro devices are continuously evolving towards miniaturization, high integration and intelligence. Micro-target devices are assembled from multiple micro-parts that are heterogeneous, anisomeric, deformable, and span different scales. In recent years, the articulated macro-micro robot (AMMR) has provided a new approach for achieving meter-scale feeding, millimeter-scale spatial alignment, and micron/sub-micron precision assembly of such micro-parts. Aiming at the problem of multi-degree-of-freedom, high-precision and collision-free pose alignment of micro parts in the narrow assembly space determined by microscopic vision and a complex environment, a dexterous-flexible performance evaluation function based assembly pose optimization method of the AMMR is proposed. Based on the mapping relationship between the motion dexterity, end deformation performance and pose, a dexterity-flexibility performance evaluation function is constructed. Using this function as the optimization objective, an assembly pose optimization model for AMMR is established. By formulating the threshold criteria and applying intelligent algorithms, the multi-variable and non-linear pose optimization solution is achieved. The effectiveness of the proposed pose optimization method is verified with the help of specific examples and experimental data. The results show that when tiny parts are assembled at the optimal assembly pose, the amplitude of the contact force generated is 0.04 N and the number of pose adjustments is 3 times, both of which are less than that corresponding to other assembly poses. In addition, the results of 10 repeat assembly experiments carried out at the optimal assembly pose show that the assembly position deviation between the micro-perforated sheet parts and the shaft is less than 3 μm.

Key words: articulated macro-micro robot, precision assembly, pose optimization, dexterity-flexibility performance evaluation function