数値解析による母指の対向運動軌道に適した7節閉ループ機構の設計

抄録

Commercially available multi-degree-of-freedom prosthetic hand designs are not functional compared to conventional 1-DOF hands. We hypothesized the thumb mechanism to be deficient and designed a single motor driven 7-Link closed-loop mechanism to oppose the thumb to the index finger in multiple prehensile forms along a single motion locus. The mechanism was modeled using the DH method and set the target motion. The target motion was set to move the thumb’s distal phalanx opposing, at first to the side of the index finger, and then to the and distal pulp of the closing fingers. The effect of the levels of link length a and link joint axis angle α’s combinations were simulated and elevated with the objective functions: angle between position vectors of initial and final distal phalanx coordinates. The combination a₃=30, a₄=95 mm, and α=100 deg. was found to be the most optimal design parameters for thumb 7-Link closed-loop mechanism.