摘要
This paper introduces the design and fabrication of a smart and Hybrid Composite Finger(HCF)to achieve finger-like motions,such as holding and tapping motions.Bionic research on tapping motion of the index finger was conducted to obtain its structural and tapping parameters.The HCF,actuated by Shape Memory Alloy(SMA)wires,possesses a hybrid structure which is composed of a rigid structure to be its metacarpal part and a deformable structure to produce bending movement just like the function of the finger.Owing to an adhesive bonding technology,the HCF was fabricated with a composite structure which is reliable under impulsive responses,and had a worklife of more than 630000 times.A bending model was built by synthesizing the phase transformation dynamic model of the SMA wires and quasi-static analysis of the HCF.Structural optimization of the HCF was conducted by synthesizing the bending model together with experimental analyses.To produce a holding motion like as the finger,a holding heating strategy was proposed to adaptively heat the HCF to keep holding state based on the resistance feedback of SMA wires and a Proportion Differentiation(PD)algorithm.Besides,we used an impulsive heating method to heat the HCF to produce a high fidelity tapping motion with a maximum tapping force(6.83 N)at a response time(43 ms)which considerably coincided with those(about 5.8 N,45 ms)from tapping bionics of the index finger.Finally,a soft prosthetic hand system which had a hand-like appearance was manufactured based on the HCFs and several tests like as anthropomorphic gesture motions and human-like tapping motions to tap a keyboard were conducted to prove potential application of the HCF.
基金
This work was supported by the National Natural Science Foundation of China(Nos.61773358 and 51705495).
