Framework for a physics-based digital twin of a towed cable-body system

• A digital twin for estimating the dynamic behaviour of cables is proposed. • Validation of a finite element cable model for oscillatory motions is presented. • Framework to predict cable dynamics from ship motion data is presented. • Ability to estimate kinematics and kinetics of cable in real-time is demonstrated. Marine towed cable-body systems undergo significant tension variations from the wave-induced ship motion, potentially causing damage or unsafe conditions due to the cable becoming slack. Accurate real-time estimation of the cable tension would enable the development of automated methods for preventing slack cable. Instead of measuring the tension using a force sensor, which may be costly and impractical in the marine environment, a Digital Twin is proposed which utilizes readily available sensor data and simulates the cable dynamics in parallel with the physical system, outputting virtual estimates of cable tension and displacement in real-time. This paper details a framework for a Digital Twin, utilizing a finite element model of a marine towed cable-body system. The finite element model is presented including definitions of the forces acting on the cable and towbody and the constraints for enforcing ship motion and cable motions. Using experimental data obtained from the literature, preliminary validation of the model was performed. The operation of the Digital Twin in real-time was demonstrated using synthetic ship motion data for a simple towing scenario, demonstrating the ability of the Digital Twin to estimate the cable tension and profile in real-time.