Structural-Parametric Synthesis of Elastic Phalanges for Adaptive Robotic Grippers Inspired by the Fin Ray Effect

An algorithm for the structural-parametric synthesis of elastic elements in the phalanges of robotic hands is presented, which provides a solution to adaptive grip problems. The use of elastic elements in the executive organs of robotic gripping devices reduces the requirements for precise finger positioning when gripping objects in an unstructured environment. The structural-parametric synthesis algorithm makes it possible to design elastic phalanges that increase the efficiency of capturing objects with different physical properties by mechanically adapting to them. To determine the topologies of phalanges intended for various classes of objects, a procedure is proposed for automating the construction of variants of elastic phalanges and evaluating their elastostatic characteristics. The design is defined by a discrete model of rigid links and elastic elements, which provides a unified representation of different topologies. By directional search for solutions, a variety of configurations with a different number of elastic elements and their location are generated; for each topology, analytical stiffness calculations, deformation modeling, and registration of force and deformation metrics are performed. The results are stored in a database for a posteriori analysis of the dependence of design parameters on functional properties and the selection of optimal solutions based on specified metrics. The algorithm is based on a computationally lightweight simulation model of nonlinear deformations of an elastic phalanx. This makes it possible to solve the optimization problem with constraints about an order of magnitude faster than using commercial engineering design environments, ensuring the reliability of modeling, the sufficiency of which is determined by verification on finite element models. The procedure of computational design of phalanx parameters as part of the finger module is implemented. To ensure physical consistency, the algorithm was validated in three stages: (1) verification of the analytical model of elastic body substitution by comparison with the results of finite element modeling; (2) determination of the initial value of the Young’s modulus on a three-point bending bench; (3) refinement of the Young’s modulus through identification of a simulation model of elastic phalanges based on physical experiments.

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