수중 무인 잠수정의 자율 운항 제어 기술

22kciothe

Active Use of Restoring Moments for Motion Control of an Underwater Vehicle-Manipulator System

This paper proposes a framework for actively using the restoring moments of an underwater vehicle-manipulator system (UVMS) considering both kinematic and control aspects. The kinematic aspect concerns redundancy resolution of the UVMS where the redundant degrees of freedom are used to selectively optimize the restoring moments. For this, a performance index with variable gradient gain is newly proposed, in which the gain is determined by the result in the comparison of the task direction with the direction of the restoring moments. The control aspect concerns compensation of the restoring forces and moments. In this framework, the control input makes up for the difference between the performances due to the desired dynamics and the restoring moments. This is accomplished by compensation of the restoring forces and moments, which are consistently updated under certain constraints. In addition, the compensation and optimal proportional-integral-derivative (PID) control are merged into a robust adaptive control. The proposed framework requires only masses, buoyant forces, and centers of gravity and buoyancy, not any hydrodynamic parameters. Numerical simulations are presented to demonstrate the performance of the proposed framework, in which a UVMS can perform specific tasks with less control input and achieve smaller tracking errors compared to conventional control systems.X111717sciescopu

구조화된 수중 환경에서 작업을 위한 PETASUS 시스템 II의 위치 인식 및 자율 제어

22kciothe

Robust coordinated motion control of an underwater vehicle-manipulator system with minimizing restoring moments

For autonomous manipulation in water, an underwater vehicle-manipulator system (UVMS) should be able to generate trajectori9es for the vehicle and manipulators and track the planned trajectories accurately. In this paper, for trajectory generation, we suggest a performance index for redundancy resolution. This index is designed to minimize the restoring moments of the UVMS during manipulation, and it is optimized without impeding the performance of a given task. As a result, the restoring moments of the UVMS are decreased, and control efforts are also reduced. For tracking control of the UVMS, a nonlinear H similar to, optimal control with disturbance observer is proposed. This control is robust against parameter uncertainties, external disturbances, and actuator nonlinearities. Numerical simulations are presented to demonstrate the performance of the proposed coordinated motion control of the UVMS. The results show that control inputs for tracking are reduced, and the UVMS can successfully track generated trajectories. (C) 2011 Elsevier Ltd. All rights reserved.X113633sciescopu

An Ethology-Based Hybrid Control Architecture for an Autonomous Underwater Vehicle for Performing Multiple Tasks

In this paper, we propose a control architecture for an autonomous underwater vehicle (AUV), implemented in a hybrid architecture with two layers: a hierarchical planning layer and a reactive execution layer. Most of its tasks are interpreted as a set of waypoints and then specified actions at the points. Thus, in the planning layer, the task planner is designed as a waypoint planner using a genetic algorithm. This planner generates an optimized plan, considering given constraints such as positions of obstacles, current velocities, and task priority. In addition, the execution of the task plan is monitored by a mission supervisor, which determines ongoing tasks and can change the original plan if exceptional events occur. In the execution layer, a behavior-based control with an ethology-based action selectionmechanismis implemented. As a result, the AUV can always choose the most appropriate behavior, maximizing itsmotivation, and the robot is controlled by the output of the selected behavior. Consequently, the proposed control architecture has an open and modular structure. Numerical simulations were conducted to verify its performance.X1145sciescopu

Preliminary design of a production automation framework for a pyroprocessing facility

Pyroprocessing technology has been regarded as a promising solution for recycling spent fuel in nuclear power plants. The Korea Atomic Energy Research Institute has been studying the current status of equipment and facilities for pyroprocessing and found that existing facilities are manually operated; therefore, their applications have been limited to laboratory scale because of low productivity and safety concerns. To extend the pyroprocessing technology to a commercial scale, the facility, including all the processing equipment and the material-handling devices, should be enhanced in view of automation. In an automated pyroprocessing facility, a supervised control system is needed to handle and manage material flow and associated operations. This article provides a preliminary design of the supervising system for pyroprocessing. In particular, a manufacturing execution system intended for an automated pyroprocessing facility, named Pyroprocessing Execution System, is proposed, by which the overall production process is automated via systematic collaboration with a planning system and a control system. Moreover, a simulation-based prototype system is presented to illustrate the operability of the proposed Pyroprocessing Execution System, and a simulation study to demonstrate the interoperability of the material-handling equipment with processing equipment is also provided. (C) 2018 Korean Nuclear Society, Published by Elsevier Korea LLC.Nuclear Research & Development Program through the National Research Foundation of Korea (NRF) - Ministry of Science, ICT & Future Planning [2015M2A8A5025906]Open Access Journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]