Sensitivity of a Submarine Manoeuvring Model to Parameter Uncertainty
Submarine manoeuvring models are used to predict performance, identify safe manoeuvring limits and provide simulation models for training platforms. A manoeuvring model for a submarine typically has many parameters, however not all of these need to be characterised with a high level of accuracy to guarantee good simulation outcomes. In order to present some guidance for the preparation of these models, the manoeuvring model of the DST generic BB1-X submarine has been analysed for parametric sensitivity.
Parameters of the well-known Gertler-Hagen based manoeuvring model were varied individually and ranked based on the simulation model’s sensitivity to their variation. A frequency domain analysis was used to indicate which modes of motion would be most affected and consequently, how the stability characteristics of the model would change.
The intent of this study was to compare parameters based on the extent to which a prescribed level of uncertainty influences the accuracy of a submarine manoeuvring simulation. The results highlight that precision may be sacrificed, or uncertainty allowed to increase, in certain parameters while not significantly affecting the motion.
This can reduce the characterisation workload and save development time and cost. It is shown that the linear damping terms had the greatest influence on the dynamic characteristics in terms of overall fidelity and stability. However, some other terms were also found to be quite significant. The findings enable future modelling studies to concentrate on characterising the critical parameters while still ensuring accurate simulations.
Modelling and Simulation Engineer
Siobhan is a Modelling & Simulation Engineer with expertise in submarine autopilots, manoeuvring simulations and captive model testing. She has completed manoeuvring performance and stability assessments of hull forms as part of SEA1000 projects and Collins Class Submarine support. Notable projects include a submarine dynamics software upgrade for the Platform Training Simulator, and the development of submarine manoeuvring limitation diagrams.
Email: Contact Siobhan