Experimental Investigation of the Hydrodynamic Coefficients of a Remotely Operated Vehicle Using a Planar Motion Mechanism

Abstract

The determination of hydrodynamic coefficients of full scale underwater vehicles using system identification (SI) is an extremely powerful technique. The procedure is based on experimental runs and on the analysis of on-board sensors and thrusters signals. The technique is cost effective and it has high repeatability; however, for open-frame underwater vehicles, it lacks accuracy due to the sensors’ noise and the poor modeling of thruster-hull and thruster-thruster interaction effects. In this work, forced oscillation tests were undertaken with a full scale open-frame underwater vehicle. These conducted tests are unique in the sense that there are not many examples in the literature taking advantage of a PMM installation for testing a prototype and; consequently, allowing the comparison between the experimental results and the ones estimated by parameter identification. The Morison’s equation inertia and drag coefficients were estimated with two parameter identification methods, that is, the weighted and the ordinary least-squares procedures. It was verified that the in-line force estimated from Morison’s equation agrees well with the measured one except in the region around the motion inversion points. On the other hand, the error analysis showed that the ordinary least-squares provided better accuracy and, therefore, was used to evaluate the ratio between inertia and drag forces for a range of Keulegan–Carpenter and Reynolds numbers. It was concluded that, although both experimental and estimation techniques proved to be powerful tools for evaluation of an open-frame underwater vehicle’s hydrodynamic coefficients, the research provided a rich amount of reference data for comparison with reduced models as well as for dynamic motion simulation of ROVs.

Research on Modeling Method of Autonomous Underwater Vehicle Based on a Physics-Informed Neural Network

“…The outcomes closely aligned with the drag coefficient results derived from experiments conducted on a full-scale AUV model. Julca Avila et al [8] conducted forced oscillation experiments on a remotely operated vehicle using a planar motion mechanism (PMM). They determined the vehicle's hydrodynamic parameters through system identification methodologies.…”

Determination of Hydrodynamic Coefficients of Atmospheric Diving Suit

“…They also conducted multiple constrained model drag tests based on the model to obtain ROV viscous hydrodynamic coefficients in the forward direction, lateral direction, and vertical direction [3]. Julca et al [4] conducted a 1:1 scale forced oscillation model test with a PMM device for ROV. Fan et al [5] conducted a large-drift-angle oblique towing test on a scale of 1:1.6 for ROV, which operates at a depth of 4500 m. A LAHPMM planar mechanism was used in their test, and based on the test data, several regression methods were used to obtain the hydrodynamic coefficients.…”

Numerical Investigation on Hydrodynamic Performance of a Portable AUV

“…These methods are usually implemented in a tank, and the support bars are fixed on some force sensors inside the hull body [16]. A practical and reliable instrument to evaluate the experimental results is the planar motion mechanism (PMM) [17], and there were many reduced or equal-sized AUV models have been made to undertake the PMM experiments for hydrodynamic coefficient estimation. Jagadeesh et al [13] presented a towing tank-based experimental investigation on forces and moment on AUV hull form in the vertical plane with a 1:2 AUV model of the standard hull form afterbody.…”