arXiv subjects

Teresa Vidal-Calleja

Publications and source records attributed to Teresa Vidal-Calleja.

39 records · Page 3Linked to original sources

arXiv2017

Remote Field Eddy Current Signal Deconvolution and Towards Inverse Modeling

Being able to quantify the corrosion of ferromagnetic water pipeline is a critical task for avoiding pipe failures. This task is often performed with Non-Destructive Evaluation (NDE) technologies and solving the inverse modeling of the sensor is considered as the holy grail of most NDE studies. In this paper, we propose a method that partly solves the inverse problem for the Remote Field Eddy Current (RFEC) technology. We consider RFEC tools with two different design, the first one is the classic design with a single exciter coil and a single receiver coil, and the second design considers the replacement of the receiver coil by an array of receivers distributed along the circumference. The proposed algorithm is tested on both simulated and real dataset.

physics.app-ph↗

arXiv2017

Multiresolution Mapping and Informative Path Planning for UAV-based Terrain Monitoring

Unmanned aerial vehicles (UAVs) can offer timely and cost-effective delivery of high-quality sensing data. How- ever, deciding when and where to take measurements in complex environments remains an open challenge. To address this issue, we introduce a new multiresolution mapping approach for informative path planning in terrain monitoring using UAVs. Our strategy exploits the spatial correlation encoded in a Gaussian Process model as a prior for Bayesian data fusion with probabilistic sensors. This allows us to incorporate altitude-dependent sensor models for aerial imaging and perform constant-time measurement updates. The resulting maps are used to plan information-rich trajectories in continuous 3-D space through a combination of grid search and evolutionary optimization. We evaluate our framework on the application of agricultural biomass monitoring. Extensive simulations show that our planner performs better than existing methods, with mean error reductions of up to 45% compared to traditional "lawnmower" coverage. We demonstrate proof of concept using a multirotor to map color in different environments.

cs.RO↗

arXiv2016

From the Skin-Depth Equation to the Inverse RFEC Sensor Model

In this paper, we tackle the direct and inverse problems for the Remote-Field Eddy-Current (RFEC) technology. The direct problem is the sensor model, where given the geometry the measurements are obtained. Conversely, the inverse problem is where the geometry needs to be estimated given the field measurements. These problems are particularly important in the field of Non-Destructive Testing (NDT) because they allow assessing the quality of the structure monitored. We solve the direct problem in a parametric fashion using Least Absolute Shrinkage and Selection Operation (LASSO). The proposed inverse model uses the parameters from the direct model to recover the thickness using least squares producing the optimal solution given the direct model. This study is restricted to the 2D axisymmetric scenario. Both, direct and inverse models, are validated using a Finite Element Analysis (FEA) environment with realistic pipe profiles.

cs.CE↗