Underwater vectored propulsion thruster is normally actuated by a step motor or a hydraulic system. The traditional actuators show an inherent shortcoming in energy consumption per volume, low space utilization and structure complexity. Shape memory alloy (SMA) based actuator is considered as a strong competitor to the traditional one, however high torque output and long movement distance to acquire high control accuracy and wide operating range still remain a big challenge. In this work, we developed an SMA-based underwater vectored thruster consisting of two motion rings and their rotary SMA actuators. Two SMA wires combined with supplementary rotation parts are utilized to drive the rotation of each motion ring. The rotary SMA actuator outputs torque that can change the angular position of underwater thruster, and the maximum angle and the response speed can be reached 38 and 1.6 s⁻¹. The experimental results verify the feasibility of applying the rotary actuator to underwater device. Modeling the SMA rotary actuator system helps understanding the rotary process of underwater vectored thruster. Based on the system model, a control scheme integrated with an anti-windup Proportion Integral Differential (PID) controller is proposed. Its performance is compared with that of the integrating angle feedback without an anti-windup block through the simulation method. With the proposed anti-windup PID controller, the results show that the overshoot can be eliminated and the steady error is decreased to 0.01% and 0.9% at 10 and 25 respectively, reflecting that the anti-windup PID controller significantly improves the system controlling performance.

水下矢量推进推进器通常由步进电动机或液压系统致动。传统的执行器在单位体积能耗，空间利用率低和结构复杂性方面存在固有的缺陷。基于形状记忆合金（SMA）的执行器被认为是传统执行器的强大竞争对手，但是，要获得高控制精度和宽工作范围，高扭矩输出和长运动距离仍然是一个很大的挑战。在这项工作中，我们开发了一种基于SMA的水下矢量推进器，该推进器由两个运动环及其旋转式SMA执行器组成。两根SMA线与辅助旋转部件相结合，用于驱动每个运动环的旋转。旋转SMA执行器输出的扭矩可以改变水下推进器的角度位置，^-1。实验结果证明了将旋转执行器应用于水下装置的可行性。对SMA旋转执行器系统进行建模有助于了解水下矢量推进器的旋转过程。基于该系统模型，提出了一种与抗饱和比例积分微分（PID）控制器集成的控制方案。通过仿真方法，将其性能与不带抗饱和块的积分角反馈的性能进行了比较。使用提出的抗饱和PID控制器，结果表明可以消除过冲，并且在10和25时稳态误差分别降至0.01％和0.9％，这表明抗饱和PID控制器显着提高了系统控制性能。