Shape Memory Alloy-Based Flexible Manipulator for Miniature Submersible Robots

摘要

This paper presents a design for a shape memory alloy (SMA) based flexible manipulator on miniature underwater RemoteOperated Vehicles (ROVs). Conventional manipulators using separate electrical motor actuators and sensors can lead toproblems in installation and control of miniature ROV during underwater operation. The size, weight and dimensions ofthe conventional manipulators are the main reasons for load interactions between ROV and manipulator which affects thestability and control. As an alternative approach here, an SMA wire trained with two-way shape memory effect and theconcept of segment actuation is presented as a flexible manipulator for miniature ROV. Forward kinematic expressions asa function of segment length are developed and used for understanding the workspace and manipulation capabilities of themanipulator. Actuation models for heating and cooling of the segments independently and the experimental validation ofthe analytical expressions for underwater application are presented. The effect of fluid interaction on the conventionalmanipulator and SMA manipulator and the stability and control effect on ROV are also discussed.