Novel Underwater Continuum Robot: Structural Design, Theoretical Modeling and Experiments

Abstract

Abstract Continuum robots have high adaptability to narrow underwater environments, because of their unique redundant degree of freedom (DOF) and post drive integration design. However, they need multiple motors to control redundant DOF, which increases the manufacturing cost and control difficulty. This paper studies and proposes a continuum robot suitable for underwater operations. The robot adopts the drive mode of the diagonal coupling gear system to realize the control of two ropes by a single motor and reduce the number of motors from 12 to 6. On this basis, motion can be achieved by rope traction on different joint groups. The kinematic model of the planar circular arc method is established to reduce the complexity of the inverse kinematics of continuous joints and improve the solving speed. The motion posture and working space are obtained through the simulation analysis. Finally, the robot’s function and load test with an arm length of 609 mm are demonstrated, and the air tightness and water tightness tests are carried out at the same time, that verify the rationality of the structure and control of the continuum robot for the underwater operation.