https://hdl.handle.net/10259/6155 2026-04-17T15:04:50Z 2026-04-17T15:04:50Z Cornejo, José Sierra Garcia, Jesús Enrique Gómez Gil, Francisco Javier Grados, Juan Palomares, Ricardo Weitzenfeld, Alfredo https://hdl.handle.net/10259/8411 2025-01-17T23:42:07Z 2024-01-01T00:00:00Z

Experimental study and geometrical method to design bio-inspired robotic kinematic chains of inching-locomotion caterpillars Cornejo, José; Sierra Garcia, Jesús Enrique; Gómez Gil, Francisco Javier; Grados, Juan; Palomares, Ricardo; Weitzenfeld, Alfredo Inching-locomotion caterpillars (ILAR) show impressive environmental adaptation, having high dexterity and flexibility. To design robots that mimic these abilities, a novel Bioinspired Robotic Design (BIROD) method is presented. The method is composed by an algorithm for Geometrical Kinematic Analysis (GEKINS) to standardize the proportional dimensions according to the insect’s anatomy and obtain the kinematic chains. The approach is experimentally applied to analyze the locomotion and kinematic chain of these specimens: Geometridae – 2 pair of prolegs (represents 35,000 species) and Plusiinae – 3 pair of prolegs (represents 400 species). The obtained data indicate that the application of the proposed method permits to locate the attachment mechanisms, joints, links, and to calculate angular displacement, angular average velocity, number of degrees of freedom, and thus the kinematic chain. Geometridae in contrast to Plusiinae, shows a longer Walk-Stride Length (WSL), a lower number of single-rotational joints in 2-D (3 DOF versus 4 DOF), and a lower number of dual-rotational joints in 3-D (6 DOF versus 8 DOF). The application of BIROD and GEKINS provides the forward kinematics for 35,400 ILAR species and are expected to be useful as a preliminary phase for the design of bio-inspired arthropod robots.

2024-01-01T00:00:00Z Serrano, Carlos Sierra Garcia, Jesús Enrique Santos, Matilde https://hdl.handle.net/10259/7569 2023-04-19T08:31:04Z 2022-11-01T00:00:00Z

Hybrid Optimized Fuzzy Pitch Controller of a Floating Wind Turbine with Fatigue Analysis Serrano, Carlos; Sierra Garcia, Jesús Enrique; Santos, Matilde Floating offshore wind turbines (FOWTs) are systems with complex and highly nonlinear dynamics; they are subjected to heavy loads, making control with classical strategies a challenge. In addition, they experience vibrations due to wind and waves. Furthermore, the control of the blade angle itself may generate vibrations. To address this issue, in this work we propose the design of an intelligent control system based on fuzzy logic to maintain the rated power of an FOWT while reducing the vibrations. A gain scheduling incremental proportional–derivative fuzzy controller is tuned by genetic algorithms (GAs) and combined with a fuzzy-lookup table to generate the pitch reference. The control gains optimized by the GA are stored in a database to ensure a proper operation for different wind and wave conditions. The software Matlab/Simulink and the simulation tool FAST are used. The latter simulates the nonlinear dynamics of a real 5 MW barge-type FOWT with irregular waves. The hybrid control strategy has been evaluated against the reference baseline controller embedded in FAST in different environmental scenarios. The comparison is assessed in terms of output power and structure stability, with up to 23% and 33% vibration suppression rate for tower top displacement and platform pitch, respectively, with the new control scheme. Fatigue damage equivalent load (DEL) of the blades has been also estimated with satisfactory results.

2022-11-01T00:00:00Z Sánchez-Martínez, Roberto Sierra Garcia, Jesús Enrique Santos, Matilde https://hdl.handle.net/10259/7554 2024-05-14T11:18:48Z 2022-12-01T00:00:00Z

Performance and Extreme Conditions Analysis Based on Iterative Modelling Algorithm for Multi-Trailer AGVs Sánchez-Martínez, Roberto; Sierra Garcia, Jesús Enrique; Santos, Matilde Automatic guidance vehicles (AGV) are industrial vehicles that play an important role in the development of smart manufacturing systems and Industry 4.0. To provide these autonomous systems with the flexibility that is required today in these industrial workspaces, AGV computational models are necessary in order to analyze their performance and design efficient planning and control strategies. To address these issues, in this work, the mathematical model and the algorithm that implement a computational control-oriented simulation model of a hybrid tricycle-differential AGV with multi-trailers have been developed. Physical factors, such as wheel-ground interaction and the effect of vertical and lateral loads on its dynamics, have been incorporated into the model. The model has been tested in simulation with two different controllers and three trajectories: a circumference, a square, and an s-shaped curve. Furthermore, it has been used to analyze extreme situations of slipping and capsizing and the influence of the number of trailers on the tracking error and the control effort. This way, the minimum lateral friction coefficient to avoid slipping and the minimum ratio between the lateral and height displacement of the center of gravity to avoid capsizing have been obtained. In addition, the effect of a change in the friction coefficient has also been simulated.

2022-12-01T00:00:00Z Martínez, Raquel Arroyo, Alberto Pigazo, Alberto Manana, Mario Bayona Blanco, Eduardo Azcondo, Francisco J. Bustamante, Sergio Laso, Alberto https://hdl.handle.net/10259/7540 2024-05-14T09:45:32Z 2022-12-01T00:00:00Z

Acoustic Noise-Based Detection of Ferroresonance Events in Isolated Neutral Power Systems with Inductive Voltage Transformers Martínez, Raquel; Arroyo, Alberto; Pigazo, Alberto; Manana, Mario; Bayona Blanco, Eduardo; Azcondo, Francisco J.; Bustamante, Sergio; Laso, Alberto Power-quality events and operation transients in power systems (PS) with isolated neutral can saturate inductive voltage transformers (IVT), which, when interacting with the overhead and underground cable capacitances, can cause ferroresonance events in the local PS. This abnormal operating mode can partially or totally damage the transformers and switchgears within the affected PS. Distribution system operators (DSO) can minimize these effects by detecting ferroresonance events accurately and fast enough and changing the mode of operation accordingly. Direct detection methods, i.e., based on voltage measurements, are reliable, but the massive deployment of this solution is relatively expensive; i.e., power quality analyzers cost thousands of USD. Alternatively, indirect detection methods are also available, e.g., IVT vibration measurements with accelerometers costing hundreds of USD, but their reliability depends on the installation method used. This manuscript proposes using the acoustic noise caused by magnetostriction forces within the IVT core during ferroresonance events to detect their occurrence. Compared to other indirect methods, electret condenser microphones with preamplifying stage cost less than USD 10 and are less sensitive to the installation procedure. The proposed method is validated experimentally, and its performance compared to IVT vibration measurements one by using the same detection methodology.

2022-12-01T00:00:00Z