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Publications (691)
This research presents an unmanned ground vehicle for identifying infested trees by bark beetles in mountain forests. The ground vehicle uses sensors for autonomous navigation and obstacle avoidance. The identification of infested trees is carried out by classifying the resin stains on the bark of unhealthy trees with a computer vision algorithm. T...
This paper addresses the robust control for a slung-mass quadrotor under abrupt velocity changes. The proposed algorithm is based on a sliding mode controller applied to the quadrotor translational dynamics considering the slung-mass angle as feedback. A Lyapunov candidate function is used to demonstrate system stability. Numerical simulations are...
This paper introduces a lower limb exoskeleton for gait rehabilitation, which has been designed to be adjustable to a wide range of patients by incorporating an extension mechanism and series elastic actuators (SEAs). This configuration adapts better to the user’s anatomy and the natural movements of the user’s joints. However, the inclusion of SEA...
This paper presents the development of the dynamical model of a planar vertical take‐off and landing (PVTOL) carrying a suspended load. The complete model is obtained using the Euler–Lagrange approach. Furthermore, the synthesis of a nonlinear control is presented that stabilizes the vehicle to a desired position, and the load is stabilized as well...
This article presents the design of a control algorithm based on Artificial Neural Networks (ANNs) applied to a lower-limb exoskeleton, which is aimed to carry out walking trajectories during lower-limb rehabilitation. The interaction between the patient and the exoskeleton leads to model uncertainties and external disturbances that are always pres...
Modelling and controlling an electrical Power Generation System (PGS), which consists of an Internal Combustion Engine (ICE) linked to an electric generator, poses a significant challenge due to various factors. These include the non-linear characteristics of the system’s components, thermal effects, mechanical vibrations, electrical noise, and the...
This study presents a novel design of an optimized chattering‐attenuated quasi‐sliding mode controller for the stabilization of a vertical take‐off and landing aircraft affected by external disturbances. We propose a methodology based on a particle swarm optimization algorithm to provide an optimal boundary layer thickness of the quasi‐sliding mode...
En este trabajo, se utiliza una estrategia difusa del tipo Takagi-Sugeno (T-S), con parámetros del modelo y control optimizados, aplicado a un sistema de generación de energía (SGE) compuesto por un motor de combustión interna (MCI) acoplado a un generador eléctrico. Con esta estrategia se evita derivar un modelo matemático mediante balance de ener...
In this paper, serial elastic actuators (SEAs) in conjunction with an accelerometer are proposed as force sensors to detect the intention of movement, and the SEA is proposed as a gentle actuator of a patient’s upper-limb exoskeleton. A smooth trajectory is proposed to provide comfortable performance. There is an offset trajectory between the link...
This article presents a virtual swashplate mechanism for a mini helicopter in classic configuration. The propeller bases are part of a passive mechanism driven by main rotor torque modulaton, this mechanism generates a synchronous and opposite change in the propellers angle of attack, then the thrust vector tilts. This approach proposes to control...
This paper proposes a new sensor using optical flow to stabilize a quadrotor when a GPS signal is not available. Normally, optical flow varies with the attitude of the aerial vehicle. This produces positive feedback on the attitude control that destabilizes the orientation of the vehicle. To avoid this, we propose a novel sensor using an optical fl...
This paper studies the modeling and control of a Planar Vertical Take-Off and Landing (PVTOL) with steerable thruster. A longitudinal model is obtained using Newton’s second law for the PVTOL which evolves in 3 degrees of freedom and has two control inputs. The aerial vehicle is driven by steerable propulsion controlling its evolution in the vertic...
Detecting people in images and videos captured from an aerial platform in wooded areas for search and rescue operations is a current problem. Detection is difficult due to the relatively small dimensions of the person captured by the sensor in relation to the environment. The environment can generate occlusion, complicating the timely detection of...
This research work describes the development of a fully actuated 6 Degree of Freedom (DOF) Unmanned Underwater Vehicle (UUV), which can be used for environmental monitoring, three-dimensional (3D) reconstruction applications, as well a research platform. The main vehicle’s characteristics are: it is designed to have easy access to all components, i...
The lack of general algorithms for the control of nonlinear systems is a generalized problem, especially when attempting to stabilize systems such as ground vehicles, which have uncertainties and are usually linearized under the assumption of small angles. To solve this problem, in this work, the implementation of a suboptimal discrete control is d...
In this paper, an optimal bounded robust control algorithm for secure autonomous navigation in quadcopter vehicles is proposed. The controller is developed combining two parts; one dedicated to stabilize the closed-loop system and the second one for dealing and estimating external disturbances as well unknown nonlinearities inherent to the real sys...
This paper presents the development of an instrumented exoskeleton with baropodometry, electromyography, and torque sensors. The six degrees of freedom (Dof) exoskeleton has a human intention detection system based on a classifier of electromyographic signals coming from four sensors placed in the muscles of the lower extremity together with baropo...
This paper proposes a robust algorithm based on a fixed-time sliding mode controller (FTSMC) for a Quadrotor aircraft. This approach is based on Lyapunov theory, which guarantees system stability. Nonlinear error dynamics techniques are used to achieve accurate trajectory tracking in the presence of disturbances. The performance of the FTSMC is com...
This paper proposes a new robust fault tolerant control architecture based on a disturbance observer. The control architecture is composed by a nominal controller and a rotor's fault observer capable to identify and estimate motors' degradation performance. Besides, is designed for a quadrotor vehicle and validated in critical and non critical moto...
An essential aspect to achieving safety with a UAV is that it operates within the limits of its capabilities, the available flight time being a key aspect when planning and executing a mission. The flight time will depend on the relationship between the available energy and the energy required by the UAV to complete the mission. This paper addresse...
This paper presents a cooperative control strategy for landing a fixed-wing drone on a mobile target vehicle. The control strategy focuses on guiding the drone along a desired trajectory while the target vehicle’s speed is controlled so that both reach the desired position simultaneously. The system model is composed by the kinematic model of a fix...
This paper deals with the references generation for a team of unmanned aerial vehicles tethered to a ground station for inspection applications. In order to deploy the team of vehicles in a suitable location to cover the largest area, each vehicle is commanded to securely navigate in an area of interest while it is tethered to another vehicle or to...
The increasing development in aerial vehicles shows a wide range of configurations for different requirements. Many of them combine conventional configurations’ features to take advantage of their qualities, such as performing a cruise flight as an airplane and hovering like a helicopter. Thereby, this study analyzes the modeling and control of a p...
In this paper, an optimal bounded robust control algorithm for secure autonomous navigation in quadcopter vehicles is proposed. The controller is developed combining two parts; one dedicated to stabilize the closed-loop system and the second one for dealing and estimating external disturbances as well unknown nonlinearities {inherent to the real sy...
This paper presents an upper limb exoskeleton that allows cognitive (through electromyography signals) and physical user interaction (through load cells sensors) for passive and active exercises that can activate neuroplasticity in the rehabilitation process of people who suffer from a neurological injury. For the exoskeleton to be easily accepted...
This work proposes a simplified control method to stabilize the model of a nonlinear Planar Vertical Take-Off and Landing (PVTOL) system when a constant force is applied in the horizontal axis. Since the stability analysis is based on a Lyapunov function, exponential stability is guaranteed when the initial conditions fall inside a domain of attrac...
In this paper, a suboptimal nonlinear discrete control for nonlinear discrete affine systems is implemented in an autonomous soaring unmanned aerial vehicle (UAV) to improve energy consumption and performance. General expressions for this controller are obtained from the continuous nonlinear guidance model of a fixed-wing UAV and applied in a multi...
The book is a comprehensive presentation of the adaptive control technology.. It presents the most important algorithms, the analysis tools for adaptive control and relevant applications in various fields.
It is a textbook for graduate students and abasic reference for practicing engineers
This article addresses the development and experimental validation of a trajectory-tracking control for a miniature autonomous Quadrotor helicopter system (X4-prototype) using a robust algorithm control based on second-order sliding mode technique or also known as super-twisting algorithm in outdoor environments. This nonlinear control strategy gua...
The development of exoskeletons has contributed to the rehabilitation of the population with different degrees of disability. These devices contemplate some feedback signals for their control; these signals can come from a user control or be taken from the brain’s or muscles’ user electrical response. In the specific case of exoskeletons of the low...
In the presented work, a trajectory is designed allowing an Unmanned Aerial Vehicle (UAV) to perform landing on a mobile platform. The proposed trajectory behaves in such a way that grants a seamless integration of information about the target landing platform into its design. This allows any generic tracking controller to follow the trajectory reg...
This article presents a new control strategy for the well‐known problem of the planar vertical take‐off and landing. The total thrust is computed using a nonlinear feedback compensation so that the altitude reaches the desired altitude. The horizontal position x is then controlled by choosing the orientation angle as a smooth saturation function of...
This paper proposes a simple flying rotor prototype composed of two small airplanes attached to each other with a rigid rod so that they can rotate around themselves. The prototype is intended to perform hover flights with more autonomy than existing classic helicopters or quad-rotors. Given that the two airplanes can fly apart from each other, the...
In this work, the analysis of the dynamic general model of an unmanned underwater vehicle (UUV) based on dual quaternions is presented, then the general dynamic model is reduced to a specific vehicle of 4 DoF, this model eliminates the singularities that exist with the representation of the Euler angle and that the model is more compact than others...
This research work focuses on the design of a robust control algorithm for 3D trajectory tracking of a 4DOF Unmanned Underwater Vehicle (UUV). The proposed strategy is based on a combination of the integral sliding mode control technique with the super-twisting controller, guaranteeing a continuous compensation of bounded disturbances and accomplis...
This paper presents how the nested saturation control introduced in Teel (1992 Teel, A. R. (1992). Global stabilization and restricted tracking for multiple integrators with bounded controls. Systems & Control Letters, 18(3), 165–171. https://doi.org/10.1016/0167-6911(92)90001-9[Crossref], [Web of Science ®] , [Google Scholar]) can be modified to s...
Two novel nonlinear control schemes for Unmanned Aerial Vehicles (UAV) carrying a load and their comparative results are presented in this paper. The goal is to carry the load to a desired position, with oscillation attenuation along the trajectory. The proposed control structures are hierarchical schemes consisting of nonlinear controllers to stab...
We present an automatic agave detection method for counting plants based on aerial data from a UAV (Unmanned Aerial Vehicle). Our objective is to autonomously count the number of agave plants in an area to aid management of the yield. An orthomosaic is obtained from agave plantations, which is then used to create a database. This database is in tur...
Control theory applied to multirotor aerial systems (MAS) has gained attention with the recent increase on the power computation for embedded systems. These systems are now able to perform the calculations needed for a variety of control techniques, with lower cost of sensors and actuators. These types of control algorithms are applied to the posit...
Hybrid Unmanned Aerial Vehicles (H-UAVs) are currently a very interesting field of research in the modern scientific community due to their ability to perform Vertical Take-Off and Landing (VTOL) and Conventional Take-Off and Landing (CTOL). This paper focuses on the Dual Tilt-wing UAV, a vehicle capable of performing both flight modes (VTOL and CT...
In this article, a suboptimal nonlinear discrete control sequence for nonlinear discrete affine control systems is proposed. Using the dynamic programming approach in discrete time domain, the suboptimal control sequence is obtained in every step considering a quadratic performance index of finite horizon. The proposed control strategy is applied t...
Disturbance rejection is a major concern nowadays for the development of autonomous aerial vehicles technology. In this way, in the control community, the researchers propose complex and robust nonlinear controllers that are in several cases so difficult to be applied in real time. In this paper, a robust linear control scheme for nonlinear aerial...
A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are d...
DC motor speed synchronization is a critical problem in industrial and robotic applications. To tackle this problem, we propose to use a multi-agent consensus-based control scheme that guarantees the convergence of the DC motor speeds to either fixed or time-varying reference. A detailed robustness analysis considering parametric uncertainty and ti...
In this paper, a Nonsingular Fast Terminal Sliding Mode Control (RNFTSMC) is proposed to regulate the position of a mobile lower limb exoskeleton powered by linear actuators with four degrees of freedom. The developed lower limb exoskeleton has the purpose to assist the sit-to-stand and stand-to-sit tasks for people with spinal cord injury (SCI) or...
Computational models of emotional learning observed in the mammalian brain have inspired diverse self-learning control approaches. These architectures are promising in terms of their fast learning ability and low computational cost. In this paper, the objective is to establish performance-guaranteed emotional learning-inspired control (ELIC) strate...
This research work focuses on the design of a robust-adaptive control algorithm for a 4DOF Unmanned Underwater Vehicle (UUV). The proposed strategy is based in a Non-Singular Terminal Sliding Mode Control (NTSMC) with adaptive gains, where the proposed adaptation mechanism ensures that the gains remain bounded. In this control strategy a non-singul...
In this chapter, various results concerning the stability of dissipative systems are presented. First, the input/output properties of several feedback interconnections of passive, negative imaginary, maximal monotone systems are reviewed. Large-scale systems are briefly treated. Then the conditions under which storage functions are Lyapunov functio...
This chapter is devoted to investigate how the dissipativity properties of the various systems examined in the foregoing chapter can be used to design stable and robust feedback controllers (in continuous and discrete time). We start with a classical result of mechanics, which actually is the basis of Lyapunov stability and Lyapunov functions theor...
The Kalman–Yakubovich–Popov Lemma (also called the Yakubovich–Kalman–Popov Lemma) is considered to be one of the cornerstones of Control and Systems Theory due to its applications in absolute stability, hyperstability, dissipativity, passivity, optimal control, adaptive control, stochastic control, and filtering. Despite its broad field of applicat...
In this chapter, we shall present a class of dissipative systems which correspond to models of physical systems, and hence embed in their structure the conservation of energy (first principle of thermodynamics) and the interaction with their environment through pairs of conjugated variables with respect to the power. First, we shall recall three di...
This chapter is dedicated to present so-called direct adaptive controllers applied to mechanical and to linear invariant systems. We have already studied some applications of dissipativity theory in the stability of adaptive schemes in Chaps. 1– 4. Direct adaptation means that one has been able to rewrite the fixed parameter input u, in a form that...
In this chapter, we present experimental results on three experimental mechanical systems. They illustrate the applicability of the methodologies exposed in the foregoing chapters. The first set of experiments concerns flexible-joint manipulators, whose dynamics and control have been thoroughly explained. One system is nonlinear and weakly flexible...
In this chapter, we will further study the concept of dissipative systems which is a very useful tool in the analysis and synthesis of control laws, for linear and nonlinear dynamical systems. One of the key properties of a dissipative dynamical system is that the total energy stored in the system decreases with time. Dissipativeness can be conside...
Positive real systems were first discovered and studied in the Networks and Circuits scientific community, by the German scientist Wilhelm Cauer in his 1926 Ph.D. thesis [1, 2, 3, 4]. However, the term positive real has been coined by Otto Brune in his 1931 Ph.D. thesis [5, 6], building upon the results of Ronald M. Foster [7] (himself inspired by...
The third edition of the now standard Dissipative Systems Analysis and Control presents a revised and expanded treatment of dissipative systems theory, constituting a self-contained, advanced introduction for graduate students, researchers and practising engineers. It examines linear, nonlinear and nonsmooth systems, with many examples in each chap...
Computational models of emotional learning observed in the mammalian brain have inspired diverse self-learning control approaches. These architectures are promising in terms of their fast learning ability and low computational cost. In this paper, the objective is to establish performance–guaranteed emotional learning–inspired control (ELIC) strate...
This work addresses the problem of two UAV (Unmanned Aerial Vehicles) transporting a slung‐load on a plane. The vehicles presented are a simplified version of the classical PVTOL (Planar Vertical Take‐Off and Landing). The proposed solution implements a decentralized control scheme based on the concept of passivity where there is no explicit commun...
This paper presents the control of a quadrotor with a cable-suspended payload. The proposed control structure is a hierarchical scheme consisting of an energy-based control (EBC) to stabilize the vehicle translational dynamics and to attenuate the payload oscillation, together with a nonlinear state feedback controller based on an linear matrix ine...
Building inspection is a vital task because infrastructure damage puts people at risk or causes economic losses. Thanks to the technological breakthroughs in regard to Unmanned Aerial Vehicles (UAVs) and intelligent systems, there is a real possibility to implement an inspection by means of these technologies. UAVs allow reaching difficult places a...
In this brief, the implementation of a suboptimal nonlinear discrete control to optimize the energy consumption in a hybrid exoskeleton for the elbow joint is presented. The exoskeleton is used to amplify the strength of the user and is hybrid in the sense that it combines two types of actuators: pneumatic muscles and Harmonic Drive motors, which g...
The problem of controlling Unmanned Aerial Vehicles (UAV) can be simplified in some cases by designing a controller for the Vertical Take-off and Landing (PVTOL) platform and adapting it to other vehicles. This is one of the reasons there is such an abundant quantity of control algorithms for this platform. The control design used in this case is f...