基于形状记忆合金驱动的仿生鲫鱼尾鳍的设计和分析

 为了研制可主动运动控制的仿生机器尾鳍,以鲫鱼的尾鳍为研究对象,利用仿生学研究结果以及形状记忆合金材料的特点,设计形状记忆合金驱动的仿生鲫鱼尾鳍结构,实现尾鳍的主动运动控制.介绍了仿生尾鳍及其驱动器的机械结构和控制方法,详细分析了核心部件形状记忆合金鳍条的根部变形曲率和摆动幅度之间的关系.最后由实验给出了形状记忆合金鳍条厚度与最大输出力及摆动幅度之间的关系,同时给出加热电流占空比对鳍条最大摆幅和最高频率的影响规律.由实验结果可知：最大输出力随着SMA薄板的厚度增加而迅速增大,它们之间呈现非线性关系；鳍条厚度和摆动幅度之间呈线性反比关系,摆动幅度随着厚度的增加线性减小；随着驱动加热电流的增加,鳍条的响应频率显著加快；不同加热电流占空比下鳍条所能达到的最大摆幅显著不同．

Mechanism design and analysis of a bionic crucian caudal fin driven by shape memory alloy actuator

In order to develop a biomimetic robot caudal fin with active motion control,we took crucian caudal fin as the research object.Upon the biological investigation results and combined with characteristics of shape memory alloy(SMA) material,we designed a bionic crucian caudal fin driven by SMA and achieved its active motion control.Firstly,we introduced the mechanical structure and control algorithm of caudal fin and its actuator.Then,we turned to the key component,viz.SMA fin ray,performing a theoretical analysis on the relationship between fin ray base deformation curvature and oscillatory amplitude.And after that,an experiment was carried out to investigate the relationship between the output force of SMA fin ray and its thickness,and simultaneously present the relationship between the oscillatory amplitude and the thickness.In addition,the influence of heating current duty cycle on the maximum oscillatory amplitude and the highest oscillatory frequency was studied.From experimental results we conclude that the output force of SMA fin ray increases non-linearly with the increase of its thickness;the oscillatory amplitude decreases linearly with the increase of its thickness;the oscillatory frequency dramatically increases with the increase of heating current;the heating current duty cycle has some influence on the maximum oscillatory amplitude.