Dynamic Response Analysis and Modal Identification of a Single-Link Underwater Long-Arm Manipulator

To enhance the efficiency of wide-range underwater operations, a single-link long-arm manipulator has been developed, featuring a carbon fiber composite arm that achieves pitching motion through a linear cylinder. To evaluate its dynamic characteristics in an underwater environment, experiments were conducted both on land and underwater. The experiment used a drive joint to excite the robotic arm, and the corresponding end response was measured using an accelerometer. The excitation and response data were then analyzed using the AutoRegressive eXogenous (ARX) method for model fitting. This model was subsequently employed for modal identification and dynamic response analysis. The findings offer essential insights into the dynamics of underwater long-arm manipulators and provide valuable methodologies for guiding the development of future control strategies.