This paper proposes a modification of a Sliding Mode Classical Observer (SMCO) to adapt it to the fractional approach. This adaptation involves using a set of definitions based on fractional calculus theory, particularly the approach developed by Riemann–Liouville, resulting in a Sliding Mode Fractional Observer (SMFO). Both observers are used to perform disturbance reconstruction considered additive in a Quadrotor Unmanned Aerial Vehicle (UAV) model. Then, this work presents the fractional-order sliding mode observer’s mathematical formulation and integration into the Quadrotor UAV model. To validate the quality of the disturbance reconstruction process of the proposed SMFO observer scheme, numerical simulations are carried out, where a reconstruction quality indicator (BQR) is proposed based on the analysis of performance indices such as the Mean Square Error (MSE), the First Probability Moment (FPM), and Second Probability Moment (SPM), which were obtained for both the SMCO and the SMFO. The simulation results demonstrate the efficacy of the proposed observer in accurately reconstructing disturbances under various environmental conditions. Comparative analyses with SMCO highlight the advantages of the fractional-order approach in terms of reconstruction accuracy and improvement of its transitory performance. Finally, the presented SMFO offers a promising avenue for enhancing the reliability and precision of disturbance estimation, ultimately contributing to the advancement of robust control strategies for Quadrotor UAV systems.
The hovering flight of a quadrotor Unmanned Aerial Vehicle (UAV) refers to maintaining the aircraft in a fixed position in the air, without lateral, vertical, or rotational movements, using only the vehicle’s control systems to maintain proper balance in all spatial dimensions. Algorithms and control systems have been developed to continuously adjust motor speeds to counteract deviations from the desired position and achieve effective hovering flight. This paper proposes a set of PID controllers with an integral effect based on the Riemann–Liouville fractional-order approach to improve the hovering flight of a quadrotor UAV. This research innovates by introducing a set of fractional-order PID controllers for UAV hover stability, which offer better adaptability to non-linear dynamics and robustness than traditional PID controllers. Also presented is the development of new performance metrics (MSE, BQC-LR), which allow for more comprehensive control system evaluations. A thorough comparative analysis with conventional control methods demonstrates the superior performance of fractional-order control in real-world simulations. The numerical simulation results show the effectiveness of the proposed Fractional Integral Action PID Controller in the control of UAV hovering flight, while comparative analyses against a classical controller emphasize the benefits of the fractional-order approach in terms of control accuracy.
The interaction of digital systems with dynamic systems requires synchrony and the accomplishment of time constrains, so the simulation of physical processes needs an implementation by means of real-time systems (RTS). However, as it can be expected, every simulation and/or implementation might demand too many computational resources, surpassing the capacity of the processor used by computational systems. This is the reason for the need to perform a temporary computational complexity analysis based on the study of the behavior of the execution times of the implemented simulation. In this regard, the Real-Time Operating Systems (RTOS) feature time managing tools, which allow their precise measurement and the establishment of scheduling criteria in process execution. Therefore, this research proposes accomplishing a temporary computational complexity analysis of the real-time simulation by an embedded system (ES) of an unmanned aerial vehicle (UAV) propelled by four rotors. Derived from this analysis, formal definitions are elaborated and proposed, which establish a close relationship between the temporary computational complexity and typical real-time temporary constraints. To the best of the author’s knowledge, the definitions presented in this article have not been reported in the literature. Furthermore, to perform the temporary computational complexity analysis of the UAV, the mathematical modeling based on the Euler–Lagrange approach is presented in detail. Finally, simulations were performed using a real-time system implemented on the Embedded Computer System (ECS) Raspberry Pi 2 Model B+, in order to validate the suggested definitions.
Nowadays, various systems were developed in the telecommunications field which make use of technologies for the transmission and reception of information. One of these technologies is the Internet, which was developed in tandem with scientific growth. Therefore, its application in the control of various industrial processes has a notable influence. In this context, there are industrial processes that, due to the potential danger they represent to human beings, must be controlled by means of a remote control system. Such systems can be implemented through client–server communication schemes, which form a network of computers to exchange information. In the exchange of information, delay times are generated. These inactivity times have a close relationship with the latency in the communication network and have a negative impact on the performance of closed-loop control systems. In this sense, for physical implementation, it is essential to measure and mathematically characterize their magnitudes in order to know their variability and thus be able to design control strategies that compensate for their effects. Hence, this research paper presents the reconstruction of the communication times measured from a telecontrol system, where it is assumed that only one subsystem acts as the controller and the other one acts as the controlled. In other words, this paper addresses a control scheme type of single-input-single-output system (SISO). This reconstruction is based on the Kalman filter, which estimates the communication times that are measured on an experimental test bench with a client–server communication scheme. Communication times are characterized as stochastic processes. So, in order to validate the reconstruction presented, the level of dependence between the random processes is evaluated by analyzing their moments of probability as well as their covariance moments. Finally, an analysis based on the mean square error is presented, through which it can be concluded that the reconstruction technique used allows one to know the dynamics of the communication times generated by the remote control process presented in this research.
Coastal regions in Mexico face significant exposure to hydrometeorological hazards, often resulting in severe flooding and socioeconomic disruption. This study assesses the hydrometeorological resilience of the Veracruz–Boca del Río Conurbation (VBC), a region comprising two coastal municipalities with shared hazard exposure despite distinct governance structures. The hydrometeorological resilience evaluation employs the City Resilience Index (CRI), developed by Bahena which integrates the Technical Resilience Index (TRI) and the Technical Profile of Resilience (TPR) across nine hierarchical indicators. Results reveal moderate resilience levels—59.83% for Veracruz and 58.32% for Boca del Río—with Disaster Risk Reduction Plans and Vital Services indicators as the strongest contributors, while Risk Assessments and Budget Allocation for Emergency Response indicators scored lowest due to limited municipal data. These findings highlight the need for enhanced data transparency, institutional coordination, and resource allocation in disaster management. Beyond its local significance, this study advances the global understanding of resilience assessment frameworks in data-scarce contexts, offering insights applicable to similar regions worldwide. As the first hydrometeorological resilience assessment for the VBC, this research provides a methodological and empirical foundation for future studies and informs targeted resilience strategies for Mexico’s coastal urban areas.
24 May 2024 in Ciencia Latina Revista Científica Multidisciplinar
En este trabajo se presenta una metodología para la adquisición de señales mioeléctricas (EMG) de miembro superior (brazo derecho) y su caracterización utilizando el primer y segundo momentos de probabilidad (media aritmética y varianza recursivas), con el objetivo de determinar el tipo de movimiento o grado de movilidad medidos. Para la adquisición de los datos se utiliza un sensor EMG con sus electrodos, una tarjeta microcontrolada Arduino, el software Tauno y una computadora con una distribución de GNU/Linux basada en Ubuntu (Zorin) comunicada por puerto USB. Como caso de estudio se analizan las señales EMG obtenidas de un paciente masculino joven saludable y sin afecciones para que las señales sean lo más confiables posibles. Al final de cada experimento se obtiene un archivo CSV para su análisis fuera de línea con el software Octave para la programación de un script que procese la información obtenida y su caracterización mediante los dos primeros momentos de probabilidad.