Real-time simulation of cable pay-out and reel-in with towed fishing gears

Abstract

Achieving real-time simulation of fast cable pay-out and reel-in manoeuvres with towed fishing gears is a challenging task. This work presents two new simulation methods based on simplified cable models for this kind of application. First, three numerical techniques are proposed to enhance a classical spring-based cable model, increasing its computational efficiency in manoeuvres that involve reeling the cable around a winch drum. Second, the development of an efficient multibody modelling approach based on natural coordinates is reported. The performance of these methods was assessed with two realistic examples. The numerical experiments involved different values of cable axial stiffness and spatial discretization levels, since these parameters were found to have a major impact on computational efficiency. The proposed methods achieved real-time performance in the simulation of systems modelled with up to a few thousand variables. Each modelling approach has advantages and limitations that must be considered when addressing a given application.

Variable-Length Cable Dynamics of Payout and Reel-in With a Vertically Tethered Underwater Drill Rig

“…where t is the time step size. Substituting the relation (28) into the equation of motion (25), the time-varying nonlinear algebraic equation set with the unknown displacement u T ,n+1 as the independent variable is obtained:…”

“…Reference [27] modeled variable-length cables between offshore oil recovery vessels and shipborne unmanned aircraft based on the updated Lagrangian method and linear rod elements, and the finite element mesh used the constant numbers of elements and nodes. Reference [28] compared a linear spring model with a rigid finite-segment model for the real-time simulation of reel-in or payout for towed fishing nets. To represent the shortening or extension of the variable-length element, the natural length of the spring was changed in the spring model and a time-varying element length parameter was introduced in the rigid finite-segment model, respectively.…”

Visually Realistic Graphical Simulation of Underwater Cable

“…Lambert created a model for the dynamics and control of towed underwater vehicle systems [8]. Gonzalez created a simulation of cable pay-out and reel-in with towed fishing gears [9]. Ablow simulated the behaviour of a long cable pulled in a circular pattern [10].…”

Self-Management of ROV Umbilical Using Sliding Buoys and Stop

“…To provide a feedback on umbilical position and form, these ones can be modeled, equipped or instrumented. Two main categories of methods can be observed in the literature: the detection of the umbilical using vision [14], [15], [16] and/or sensor placed directly on/in the umbilical to obtain a feedback on its shape [7], [10], or a direct modeling of the umbilical using only boat and ROV position [11], [12], [9], sometimes with an a-prior knowledge of underwater current. The main advantage of the first category is the accuracy of the model obtained, often in real time.…”