Non-Linear Modeling and Simulation with 3-D Animation for 6-DOF Autonomous Underwater Vehicle

Author(s):  
Sherif M. Hassan ◽  
Mohammed A. H. AboZied ◽  
Ahmed Khamis ◽  
Dawid Zydek
Author(s):  
Ravish H. Hirpara ◽  
Shambhu N. Sharma

This paper revisits the state vector of an autonomous underwater vehicle (AUV) dynamics coupled with the underwater Markovian stochasticity in the ‘non-linear filtering’ context. The underwater stochasticity is attributed to atmospheric turbulence, planetary interactions, sea surface conditions and astronomical phenomena. In this paper, we adopt the Itô process, a homogeneous Markov process, to describe the AUV state vector evolution equation. This paper accounts for the process noise as well as observation noise correction terms by considering the underwater filtering model. The non-linear filtering of the paper is achieved using the Kolmogorov backward equation and the evolution of the conditional characteristic function. The non-linear filtering equation is the cornerstone formalism of stochastic optimal control systems. Most notably, this paper introduces the non-linear filtering theory into an underwater vehicle stochastic system by constructing a lemma and a theorem for the underwater vehicle stochastic differential equation that were not available in the literature.


2012 ◽  
Vol 26 (4) ◽  
pp. 603-622 ◽  
Author(s):  
Wen-long Tian ◽  
Bao-wei Song ◽  
Xiao-xu Du ◽  
Zhao-yong Mao ◽  
Hao Ding

2011 ◽  
Vol 8 (2) ◽  
pp. 149-163 ◽  
Author(s):  
R Sakthivel ◽  
S Vengadesan ◽  
S K Bhattacharyya

This paper addresses the Computational Fluid Dynamics Approach (CFD) to simulate the flow over underwater axisymmetric bodies at higher angle of attacks.  Three Dimensional (3D) flow simulation is carried out over MAYA Autonomous Underwater Vehicle (AUV) at a Reynolds number (Re) of 2.09×106. These 3D flows are complex due to cross flow interaction with hull which produces nonlinearity in the flow. Cross flow interaction between pressure side and suction side is studied in the presence of angle of attack. For the present study standard k-ε model, non-linear k-ε model models of turbulence are used for solving the Reynolds Averaged Navier-Stokes Equation (RANS). The non-linear k-ε turbulence model is validated against DARPA Suboff axisymmetric hull and its applicability for flow simulation over underwater axisymmetric hull is examined. The non-linear k-ε model performs well in 3D complex turbulent flows with flow separation and flow reattachment.  The effect of angle of attack over flow structure, force coefficients and wall related flow variables are discussed in detail. Keywords: Computational Fluid Dynamics (CFD); Autonomous Underwater Vehicle (AUV); Reynolds averaged Navier-Stokes Equation (RANS); non-linear k-ε turbulence modeldoi: http://dx.doi.org/10.3329/jname.v8i2.6984   Journal of Naval Architecture and Marine Engineering 8(2011) 149-163


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