基于SMA柔性驱动器的机器鱼设计与试验

Design and Experiment of Robotic Fish Based on SMA Flexible Actuators

设计了一款基于形状记忆合金丝(SMA)柔性驱动的机器鱼,详细阐述了柔性驱动器和机器鱼的结构设计和制作工艺,同时设计制作了驱动器和机器鱼的电控系统。柔性驱动器可实现双向弯曲运动,驱动器每一侧布置4路可独立控制的SMA丝,通过选择不同加热路数,可实现机器鱼四级摆动幅度的较精确控制。针对SMA存在的热积累问题,结合柔性驱动器自身的特点,提出了一种轮询加热控制策略,并试验比较了驱动器摆动幅度和摆动频率对机器鱼直线游动行为的影响。试验结果表明,柔性驱动器的摆动幅度越大,机器鱼游速越快;在无SMA热积累的影响下,驱动器的摆动频率越快,机器鱼游速也越快;轮询加热控制策略可有效提高机器鱼的极限摆动频率,获得的最大游速为102mm/s。

A robotic fish actuated by a flexible actuator based on shape memory alloy wire（SMA）was designed.The structural design and workmanship of the flexible actuator and the robotic fish were elaborated.At the same time,the electronic control system of the robotic fish and the actuators were designed.The flexible actuator can bend in two directions.Four independent SMA wires were arranged on each side of the actuator,which can realize the accurate four bending amplitude of the robotic fish by choosing different heating channels.Due to the problem of SMA heat accumulation,a round-robin heating control strategy was proposed based on the characteristics of the actuator,and the influence of the amplitude and frequency of the actuator on the straight swimming of the robotic fish was experimentally compared.The experimental results showed that the velocity of the robotic fish increased when the amplitude and frequency of the actuator increased,without the influence of SMA heat accumulation,the faster actuators vibrated,the faster robotic fish swam.The round-robin control strategy can increase the limit bending frequency of the robotic fish effectively,and the maximum speed was 102 mm/s.