Estimations of on-site directional wave spectra from measured ship responses

Nielsen, Ulrik Dam

doi:10.1016/j.marstruc.2006.06.001

Cited by 129 publications

(105 citation statements)

References 10 publications

Supporting

Mentioning

103

Contrasting

Unclassified

Order By: Relevance

“…Here, two approaches are tested in full-scale scenarios. The fi rst is based on the use of a wave radar, e.g., the WAVEX system (Borge et al 3 ), and the second uses ship responses (e.g., motions, accelerations, and strains) measured in real time by sensors installed on board together with linear transfer functions to estimate the sea state, see the work of Nielsen,4 in which a comparison between the two approaches is also found.…”

Section: Introductionmentioning

confidence: 99%

Efficient estimation of extreme non-linear roll motions using the first-order reliability method (FORM)

Jensen

2007

J Mar Sci Technol

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Efficient estimation of extreme non-linear roll motions using the first-order reliability method (FORM)

Jensen

2007

J Mar Sci Technol

View full text Add to dashboard Cite

“…In case sea state estimation is conducted by a ship-wave buoy analogy e.g. [2], [3], it is sufficient to use three different ship responses and usually we have more at our disposal.…”

Section: Increasing the Overall Dependabilitymentioning

confidence: 99%

“…In this paper has been applied the Parametric method [2], [18] to estimate the on-site directional wave spectrum. On the assumption that the ship responses are stationary and linear with the incident waves, the complex-valued transfer functions and for the i-th and j-th responses yield the theoretical relationship between the i-th and j-th components of the cross spectra and the directional wave spectrum through the following integral equation [2].…”

Section: Wave Estimationmentioning

confidence: 99%

“…Since all the measurements have been taken on the ship, the frequency of encounter should be considered only. As already mentioned, in case sea state estimation is conducted by a shipwave buoy analogy [2], [3], it is sufficient to use three different ship motions (or responses). Therefore, it would be convenient to have expressions that relate three different ship responses, which is readily obtained from Eqs.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Fault Isolation and Quality Assessment for Shipboard Monitoring

Lajic

Nielsen

Blanke

2010

29th International Conference on Ocean, Offshore and Arctic Engineering: Volume 4

Self Cite

View full text Add to dashboard Cite

In this paper a new approach for increasing the overall reliability of a monitoring and decision support system will be explained. The focus is on systems used for ship operator guidance with respect to, say, speed and heading. The basic idea is to convert the given system into a fault tolerant system and to improve multi-sensor data fusion for the particular system. Fault isolation is an important part of the fault tolerant design for in-service monitoring and decision support systems for ships. In the paper, a virtual example of fault isolation will be presented. Several possible faults will be simulated and isolated using residuals and the generalized likelihood ratio (GLR) algorithm. It will be demonstrated that the approach can be used to increase accuracy of sea state estimations employing sensor fusion quality test.

show abstract

“…The SeaSense system makes estimations of the sea state by use of a simplified version of the wave buoy-analogy, where measured ship responses are used to estimate the directional wave spectrum, e.g. Nielsen [16] and Iseki and Terada [6].…”

Section: Introductionmentioning

confidence: 99%

A step towards risk-based decision support for ships – Evaluation of limit states using parallel system analysis

2009

Self Cite

View full text Add to dashboard Cite

hours taking into account speed and course changes, assuming stationary sea states. In principle, the calculations depend on a large amount of operational and environmental parameters, which will be known only in the statistical sense. The present paper suggests a procedure to incorporate random variables and associated uncertainties in the calculations of the outcrossing rates that are the basis for risk-based DSS. The procedure is based on parallel system analysis, and the paper derives and describes the main ideas. The concept is illustrated by an example, where the limit state of a non-linear ship response is considered. The results from the parallel system analysis are in agreement with corresponding Monte Carlo simulations. However, the computational speed of the parallel system analysis proved slower than expected.

show abstract

Estimations of on-site directional wave spectra from measured ship responses

Cited by 129 publications

References 10 publications

Efficient estimation of extreme non-linear roll motions using the first-order reliability method (FORM)

Efficient estimation of extreme non-linear roll motions using the first-order reliability method (FORM)

Fault Isolation and Quality Assessment for Shipboard Monitoring

A step towards risk-based decision support for ships – Evaluation of limit states using parallel system analysis

Contact Info

Product

Resources

About