Manipulability analysis of underwater robotic arms on ROV and application to task-oriented joint configuration

Abstract

This paper describes the task-oriented manipulability of tele-operated robotic arms mounted on a remotely operated vehicle (ROV) and its application to task-oriented joint configurations. The main purpose of the study is to reduce the tele-operator's burden in performing underwater tasks by enhancing the functionality of the manipulator. Even though a manipulator has 6 degrees-of-freedom (DOF), which is proper DOF to work in Cartesian workspace, the manipulator might have redundancy according to task types and order of task-priority. This paper focuses on the problem to utilize the redundancy by introducing a scalar function as an object of optimization. The scalar function is composed of a taskoriented manipulability measure (TOMM) and joint limit measure (JLM). Using sequential quadratic programming (SQP) with the object function, we obtained optimal postures of the manipulator for a given position constraint of the end-effecter. Adopting the scalar function as a performance index, we solved a redundancy resolution problem based on the pseudo inverse of the task-oriented Jacobian matrix.

Study of manipulator operations maneuvered by a ROV in virtual environments

“…The experimental results demonstrate the feasibility and effectiveness of our virtual platform. In addition, the virtual platform can not only be used to test and validate motion control methods for operating the submersible vehicle and manipulator (Jun et al, 2008;Li and Wan, 2011), but also it can be used as an auxiliary control system to display the motion state and trajectory of the real submersible vehicle and underwater manipulator where the developers do not have a direct view of the system (Ge and Guo, 2012).…”

“…The modes to operate the underwater manipulator can be divided into remote operation and autonomous operation. The remote operational mode to the underwater manipulator mainly includes remotely operating the joints through joysticks (Sheikhbahaee et al, 2014), remotely operating the pose position and orientation of the endeffector through joysticks (Shim et al, 2010), and remotely operating the manipulator through a master arm (Jun et al, 2008). The joystickbased manipulator and the master arm-based manipulator are named switch manipulator and master-slave manipulator, respectively.…”

“…We considered some external disturbances while training the operator. This platform is able to serve as a preliminary validation tool to test the motion control methods of ROVs and manipulators in the real world (Jun et al, 2008;Koivumäki and Mattila, 2016;Shim et al, 2010).…”

Development of a Virtual Platform for Telepresence Control of an Underwater Manipulator Mounted on a Submersible Vehicle

“…Due to the irreplaceable performance in unstructured and complicated subsea environments, the master arm-based method [10][11][12][13] is mostly used for controlling underwater manipulators, in which an operator controls a large slave arm by operating its miniature replica as a master arm. Controlling the underwater manipulator mounted on a submersible vehicle by operating the master arm to perform underwater operations accurately and efficiently requires a high level of operational skills, because there are uncertain disturbances and visual impacts from the subsea environment.…”

Investigation into the Dynamics and Control of an Underwater Vehicle-Manipulator System

“…A nonlinear model-based control scheme that controlled the vehicle and manipulator simultaneously was developed and investigated [8]. In addition to these studies, some of the researches were focused on estimating hydrodynamic parameters of these systems [8], the reduction of the interaction effects (dynamic coupling) between the manipulator and the vehicle [9], and the manipulability and workspace analysis of the underwater manipulator on remotely operated vehicle (ROV) [10]. Also, there have been many studies on manipulator control for enhancing efficiency of underwater manipulation, such as the force feedback control of manipulators mounted on ROVs [11], motion planning, and control of UVMS [7], computer-based control, and real-time motion compensation of UVMS [12].…”