Dynamic Analysis of the UVMS: Effect of Disturbances, Coupling, and Joint-Flexibility on End-Effector Positioning

Robotica ◽  
2021 ◽  
pp. 1-29
Author(s):  
Umer Hameed Shah ◽  
Mansour Karkoub ◽  
Deniz Kerimoglu ◽  
Hong-Du Wang
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Added Mass ◽  
Hydrodynamic Forces ◽  
Viscous Damping ◽  
End Effector ◽  
Flexible Joint ◽  
Lagrange Formulation ◽  
System Coupling ◽  
Flexible Joint Manipulator

SUMMARY This paper investigates the dynamics of an underwater vehicle-manipulator system (UVMS) consisting of a two-link flexible-joint manipulator affixed to an autonomous underwater vehicle. The quasi-Lagrange formulation is utilized in deriving a realistic mathematical model of the UVMS considering joints’ friction, hysteretic coupling between the joints and links, and the nonlinear hydrodynamic forces acting on the system, such as added mass, viscous damping, buoyancy, drag, and vortex-induced forces. Numerical simulations are performed to demonstrate the effects of hydrodynamic forces and system coupling between the vehicle and the manipulator and the joints and the links on the precise positioning of the end effector.

scholarly journals Dynamic Neural Network-Based Adaptive Tracking Control for an Autonomous Underwater Vehicle Subject to Modeling and Parametric Uncertainties

2021 ◽  
Vol 11 (6) ◽  
pp. 2797
Author(s):  
Filiberto Muñoz ◽  
Jorge S. Cervantes-Rojas ◽  
Jose M. Valdovinos ◽  
Omar Sandre-Hernández ◽  
Sergio Salazar ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Neural Control ◽  
Autonomous Underwater Vehicle ◽  
Parametric Uncertainty ◽  
Underwater Vehicle ◽  
Added Mass ◽  
Parametric Estimation ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Adaptive Tracking Control

This research presents a way to improve the autonomous maneuvering capability of a four-degrees-of-freedom (4DOF) autonomous underwater vehicle (AUV) to perform trajectory tracking tasks in a disturbed underwater environment. This study considers four second-order input-affine nonlinear equations for the translational (x,y,z) and rotational (heading) dynamics of a real AUV subject to hydrodynamic parameter uncertainties (added mass and damping coefficients), unknown damping dynamics, and external disturbances. We proposed an identification-control scheme for each dynamic named Dynamic Neural Control System (DNCS) as a combination of an adaptive neural controller based on nonparametric identification of the effect of unknown dynamics and external disturbances, and on parametric estimation of the added mass dependent input gain. Several numerical simulations validate the satisfactory performance of the proposed DNCS tracking reference trajectories in comparison with a conventional feedback controller with no adaptive compensation. Some graphics showing dynamic approximation of the lumped disturbance as well as estimation of the parametric uncertainty are depicted, validating effective operation of the proposed DNCS when the system is almost completely unknown.

Vibration Suppression of the Flexible Joint Manipulator Based on Controllable Local Degrees of Freedom

2011 ◽  
Vol 66-68 ◽  
pp. 989-994
Author(s):  
Zhi Hui Gao ◽  
Jing Jing Yu ◽  
Yu Shu Bian
Keyword(s):  
Vibration Control ◽  
Control Strategy ◽  
Topological Structure ◽  
Degrees Of Freedom ◽  
Vibration Suppression ◽  
Dynamic Performance ◽  
End Effector ◽  
Flexible Joint ◽  
Local Degree ◽  
Flexible Joint Manipulator

In order to suppress vibration of the flexible-joint manipulator, a new topological structure of the manipulator with the controllable local degrees of freedom is suggested. By kinematic and dynamic analysis, it is found that arbitrary motions introduced by the controllable local degrees of freedom are independent of the nominal end-effector motion, but can greatly affect dynamic performance of the manipulator. As a result, a vibration control strategy is put forward based on the controllable local degree of freedom. By planning the branch link motion, the vibration of the flexible-joint manipulator can be reduced. The results of numerical simulations verify the effectiveness of the vibration control strategy proposed in this paper.

scholarly journals Hydrodynamic and Dynamic Analysis to Determine the Longitudinal Hydrodynamic Coefficients of an Autonomous Underwater Vehicle

2020 ◽  
Vol 30 (7) ◽  
pp. 43-48
Author(s):  
Quang Le ◽  
Anh Tuan Phan ◽  
Thi Thanh Huong Pham
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Stability ◽  
Dynamic Simulation ◽  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Hydrodynamic Forces ◽  
Experimental Results ◽  
Hydrodynamic Coefficients ◽  
Underwater Environment

A useful tool for understanding the performance of an Autonomous Underwater Vehicle (AUV) is a dynamic simulation of the motions of the vehicle. To perform the simulation, the hydrodynamic coefficients of the vehicle must be first provided. These coefficients are specific to the vehicle and provide the description of hydrodynamic forces and moments acting on the vehicle in an underwater environment. This paper provides a method for the calculation and evaluation of the hydrodynamic coefficients of an AUV. The presence methodology is therefore one useful tool for determining an underwater vehicle’s dynamic stability. The calculated values have been compared with experimental results of a torpedo shape. It was concluded that the methods could calculate accurate values of the hydrodynamic coefficients for a specific AUV shape with its elliptical nose

Development of a Semi-Autonomous Underwater Vehicle for Intervention Missions (SAUVIM Phase III-B)

2009 ◽  
Author(s):  
Giacomo Marani ◽  
Junku Yuh ◽  
Song K. Choi ◽  
Son-Cheol Yu ◽  
Luca Gambella ◽  
...  
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Phase Iii
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