System of automatic stabilization of underwater vehicle in hang mode with working multilink manipulator

Abstract

In this work the synthesis method of combined closed-loop automatic system of underwater vehicle position and orientation stabilization in hang mode (station keeping regime) is described. Underwater vehicle invariance to external influences created by working underwater manipulator is provided by thrusts of vehicle screws. These thrusts are proportional to said external influences calculated in real time scale. For precise calculation of these influences the recursive algorithm for solving of inverse problem of underwater manipulator dynamic was developed. Presented algorithm allows to take into account all features of viscous environment influences on manipulator links committing random movements at high speed. To increase accuracy of underwater vehicle stabilization additional automatic closed-loop systems for all linear and angular movement of this vehicle was synthesized. Said systems can use data obtained from high-precision navigation onboard sensors and devices.

Development of Fault Accommodation System for Actuators of Underwater Manipulators

“…Each degree of freedom is actuated by corresponding actuator. For definition of external generalized moment arising in all degrees of freedom of UM at the motion in water, it is possible to use recurrent algorithm for solving inverse dynamics problem of the UM [17]. This algorithm is based on well-known two-staged computational structure.…”

“…These moments are caused by inertial and gravitational forces and forces determined by interaction of working UMs and viscous environment [17]. At this case, the actuators of UMs will be described by nonlinear equations with variable parameters.…”

Technology for Automatic Soil Sampling by Manipulators Mounted on Underwater Vehicles

“…Until the point C a satisfying the condition (6) appears, the UV should keep slow submerging to the bottom. When the point C a appears, the UV stops and has to be fixed in this position with help of stabilization systems [5][6][7][8].…”

“…For the taking into account negative angular displacements of the UV under the influence of the grasped objects and probes the methods [3,4] are developed. The technologies for high-precision automatic stabilization of the UV in the hang mode [5][6][7][8] are already created. These stabilization systems allow to perform manipulation operations without additional mechanical devices for the UV rigid fixation near work objects and exclude the introducing of disturbances into bottom layers of water.…”

Control System for Underwater Vehicle With Multilink Manipulator for Automatic Manipulation Operations

“…Methods and approaches that guarantee high precision holding of the UV near WO have been also developed [6][7][8][9]. It allows fixing the UV in the determined spatial point with desired spatial orientation and without grounding and roiling of near-bottom layers.…”