Design, Prototyping and Test of a Dual-Arm Continuum Robot for Underwater Environments

The decommissioning of nuclear sites is a significant and growing engineering challenge often requiring specialist equipment, especially when the nuclear site is partially submerged with contaminated water. However, most currently available decommissioning tools are large, bulky structures that lack dexterity. In this paper, a novel dual-arm continuum robot, which is composed of two 6-degree of freedom (DoF) continuum arms that can be simultaneously employed, is developed. To improve the mechanical performance of the continuum arms, additional compliant mechanisms (flexure hinges) were integrated into its design. By combining the dual-arm continuum robot with a commercial unmanned underwater vehicle (UUV), the system can be deployed in many underwater engineering scenarios to conduct complicated tasks. The prototyped dual-arm continuum robot and its control system has been tested to ascertain its kinematic accuracy. It was found the average displacement error is within 5.7% of the 6-DoF continuum robot (length: 540 mm), proving its potential for high-accuracy operation.