Persona:
Cerrada Somolinos, José Antonio

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ORCID
0000-0001-5492-5293
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Proyectos de investigación
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Cerrada Somolinos
Nombre de pila
José Antonio
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2017 - 20194
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Nivel de acceso: info:eu-repo/semantics/openAccess × Autor: Herrera Caro, Pedro Javier ×

Resultados de la búsqueda

Mostrando 1 - 4 de 4
  • Miniatura
    Publicación
    A Simplified Optimal Path Following Controller for an Agricultural Skid-Steering Robot
    (Institute of Electrical and Electronics Engineers, 2019-08-02) Fernandez, Benjamin; Herrera Caro, Pedro Javier; Cerrada Somolinos, José Antonio
    The dynamics of a skid-steering robot present intrinsic non-linearities that make the design and implementation of a controller a very complex task, time-consuming, and difficult to implement into an embedded system with limited resources. This paper presents a simplified first order digital model approximation and an optimal observer-based control approach for the tracking of the lateral position of such robots. In order to verify the validity of this proposal, 3D real-time interactive simulations and real validations with an agricultural skid-steering robot were performed with satisfactory results.
  • Miniatura
    Publicación
    Self-tuning Regulator for a Tractor with Varying Speed and Hitch Forces
    (Elsevier, 2018-02) Fernandez, Benjamin; Herrera Caro, Pedro Javier; Cerrada Somolinos, José Antonio
    Due to the changes in the soil, speed and hitch forces, the dynamics of a farm tractor are constantly changing making the design of an autonomous lane-tracking controller a very complex task. To be able to react to those changes, this paper presents a new adaptive system based on a self-tuning regulator made up of a recursive least-squares parameter identification algorithm for the plant combined with a minimum-degree pole placement (MDPP) method for changing the parameters of a digital RST controller in real time. The MDPP is computed by solving the Diophantine equation for the desired closed-loop reference model. The results presented show how the system is able to adapt the control parameters for different speeds and changes in the hitch cornering stiffness. As future work, this method could also be applied and assessed as a general controller, covering different sizes and different types of steering systems for off-road vehicles.
  • Miniatura
    Publicación
    Robust digital control for autonomous skid-steered agricultural robots
    (Elsevier, 2018-10) Fernández, Benjamín; Herrera Caro, Pedro Javier; Cerrada Somolinos, José Antonio
    There are two main issues to consider when designing a controller for autonomous off-road vehicles: velocity and terrain irregularities. Whereas the first one is measurable, the second one is very difficult to determine. Solutions to cover these issues could be very complex and difficult to implement in an embedded system with limited resources. The results obtained in our previous research for an adaptive approach implemented in a tractor with varying hitch forces, lead to the improvements presented here. This paper proposes a robust digital RST pole placement controller design for the lateral position, with sensitivity functions tuned to cover uncertainties and non-linearities not considered in the model. Simulations were implemented to assess the performance of the system and the controller implementation was applied to a skid-steered agricultural robot with limited computational resources and a state-of-the-art navigation system, which delivered satisfactory results.
  • Miniatura
    Publicación
    A vision-based strategy to segment and localize ancient symbols written in stone
    (Springer, 2017-12-21) Duque Domingo, Jaime; Herrera Caro, Pedro Javier; Cerrada Somolinos, Carlos; Cerrada Somolinos, José Antonio; https://orcid.org/0000-0001-6649-5550; https://orcid.org/0000-0001-8679-6617; https://orcid.org/0000-0002-8591-6581; https://orcid.org/0000-0001-5492-5293
    This work proposes an automatic method to detect ancient symbols written in stone. The proposed method takes into account well-known techniques used in computer vision to identify the contour of the symbols in the image. The two-stage method consists of segmentation and localization processes. Segmentation process includes a pre-processing step, edge detection and thresholding. Localization process is based on two conditions that take into account several parameters, like the distance between points, and the orientation and the continuity of the edges. This proposal has been applied to localize Egyptian cartouches (borders enclosing the name of a king) and stonemason’s marks from images obtained under varying lighting conditions (controlled and natural lighting). The proposed method is compared favorably against other methods based on chain coding, neural networks and statistical correlation. The promising results give new possibilities to identify and recognize complex symbols and ancient texts.