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Filip Van Utterbeeck

Publications and source records attributed to Filip Van Utterbeeck.

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A Stochastic Optimal Control Formulation for Mine Counter Measure Simulations with Multiple Autonomous Survey Vehicles

Modelling and simulating mine counter measure search missions performed by autonomous vehicles equipped with a sensor capable of detecting mines at sea is a challenging endeavour. To address this, we formulated and implemented the problem as a stochastic optimal control model. Our implementation computes an optimal path within a user chosen quadrilateral domain such that the mission duration is minimized for a given residual risk of undetected sea mines. First, we compare the stochastic optimal control implementation against the traditionally used boustrophedon implementation. We show that the mission duration in case of the stochastic optimal control implementation is shorter. Then, by building on our previous work, we introduce a novel mathematical approach that enables multiple autonomous survey vehicles to investigate the domain concurrently. We present results for up to six vehicles, including computed trajectories and an analysis of how mission duration varies with the number of vehicles. Our findings show that mission time decreases non-linearly, , i.e., we observe diminishing returns as more vehicles are added.

math.OC

Application of quasi-Monte Carlo in Mine Countermeasure Simulations with a Stochastic Optimal Control Framework

Modelling and simulating mine countermeasures search missions performed by autonomous vehicles equipped with a sensor capable of detecting mines at sea is a challenging endeavour. The output of our stochastic optimal control implementation consists of an optimal trajectory in a square domain for the autonomous vehicle such that the total mission time is minimized for a given residual risk of not detecting sea mines. We model this risk as an expected value integral. We found that upon completion of the simulation, the user requested residual risk is usually not satisfied. We solved this by implementing a relaxation strategy which consists of incrementally increasing the square search domain. We then combined this strategy with different quasi-Monte Carlo schemes used for solving the integral. We found that using a Rank-1 Lattice scheme yields a speedup up to a factor two with respect to the Monte Carlo scheme. We also present an implementation which allows us to compute a trajectory in a convex quadrilateral domain, as opposed to a square domain, and combine it with our relaxation strategy.

math.NA

Modelling sand ripples in mine countermeasure simulations by means of stochastic optimal control

Modelling and simulating mine countermeasures (MCM) search missions performed by autonomous vehicles equipped with a sensor capable of detecting mines at sea is a challenging endeavour. In this work, we present a novel way to model and account for sand ripples present on the bottom of the ocean while calculating trajectories for the autonomous vehicles by means of a stochastic optimal control framework. It is known from the scientific literature that these ripples impact the sea mine detection capabilities of the autonomous vehicles.

math.NA

Comparative analysis of graph randomization: Tools,methods, pitfalls, and best practices

Graph randomization techniques play a crucial role in network analysis, allowing researchers to assess the statistical significance of observed network properties and distinguish meaningful patterns from random fluctuations. In this survey we provide an overview of the graph randomization methods available in the most popular software tools for network analysis. We propose a comparative analysis of popular software tools to highlight their functionalities and limitations. Through case studies involving diverse graph types, we demonstrate how different randomization methods can lead to divergent conclusions, emphasizing the importance of careful method selection based on the characteristics of the observed network and the research question at hand. This survey proposes some guidelines for researchers and practitioners seeking to understand and utilize graph randomization techniques effectively in their network analysis projects.

physics.soc-ph