December 2024
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14 Reads
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December 2024
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14 Reads
December 2024
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30 Reads
Drones
An Image-Based Visual Servoing Control (IBVS) structure for target tracking by Unmanned Aerial Vehicles (UAVs) is presented. The scheme contains two stages. The first one is a sliding-model controller (SMC) that allows one to track a target with a UAV; the control strategy is designed in the function of the image. The proposed SMC control strategy is commonly used in control systems that present high non-linearities and that are always exposed to external disturbances; these disturbances can be caused by environmental conditions or induced by the estimation of the position and/or velocity of the target to be tracked. In the second instance, a controller is placed to compensate the UAV dynamics; this is a controller that allows one to compensate the velocity errors that are produced by the dynamic effects of the UAV. In addition, the corresponding stability analysis of the sliding mode-based visual servo controller and the sliding mode dynamic compensation control is presented. The proposed control scheme employs the kinematics and dynamics of the robot by presenting a cascade control based on the same control strategy. In order to evaluate the proposed scheme for tracking moving targets, experimental tests are carried out in a semi-structured working environment with the hexarotor-type aerial robot. For detection and image processing, the Opencv C++ library is used; the data are published in an ROS topic at a frequency of 50 Hz. The robot controller is implemented in the mathematical software Matlab.
March 2024
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50 Reads
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4 Citations
Robotics and Autonomous Systems
September 2023
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27 Reads
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1 Citation
IEEE International Conference on Rehabilitation Robotics : [proceedings]
Acquired Brain Injury (ABI) causes permanent disabilities, such as foot drop. This condition affects the gait pattern, increasing the metabolic cost and risk of falling. Robotics with serious games has shown promising results in the gait rehabilitation context. This paper aims to analyze the effects of using the T-FLEX exoskeleton with (1) Automated Therapy (AT) and (2) Serious Game Therapy (SGT) in two ABI patients. Each participant completed six assisted sessions for each strategy. Results showed that AT increases the user-robot interaction torque by 10% for the first patient and 70% for the second patient, and SGT decreases by 5% for both patients. This way, SGT required the patient to generate torque to execute the ankle movement, while AT did the opposite, resulting in greater device assistance. In the functional assessment, SGT induced variations greater than 50% for the paretic ankle and knee's range of motion (ROM), indicating a potential for motor recovery. Thus, SGT led to improved ankle control and increased gait speed compared to AT. These findings suggest that SGT may be an effective rehabilitation strategy for ABI-related foot drop patients.
July 2023
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35 Reads
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4 Citations
IEEE Transactions on Control Systems Technology
Interest in multilift rotorcraft systems has reemerged in recent years to overcome some of the problems in single unmanned aerial vehicle handling and delivery systems. Using multiple unmanned rotorcrafts (URs), the load weight can be evenly distributed among the vehicles, extending the flight time and therefore increasing the working distance of such systems. Moreover, with a slung-load configuration, bigger size packages with complex shape and equipment that may interfere with the onboard electronics can be carried. In this context, this article presents a payload-based unified motion control that allows any number of URs to cooperatively transport a slung load in forward flight. The motion control comprises path-following and trajectory-tracking algorithms, considers obstacle avoidance, implements a specific strategy for load weight distribution (load equalization) by regulating the relative altitude of each UR, and is robust to disturbances such as wind. In addition, this work shows that load equalization is essential for slung-load cooperative transport, especially in forward flight. The controller’s stability is analytically studied and the good performance of the system is demonstrated through exhaustive simulations using validated dynamic models for mini-helicopters, cables, and payload. Finally, the relation between load weight and number of URs is analyzed by considering several scenarios.
June 2023
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20 Reads
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6 Citations
Mechatronics
March 2023
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22 Reads
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11 Citations
Array
In the present work the capability of convolutional neural networks to extract samples of leaves in images of tree’s canopy and detect the presence of different diseases and pests that manifest in deformation, discoloration or direct presence in the leaves, is studied. The sample obtained along with its location and sampling date, allows a mapping of the diseases in the field. This mapping capability will allow better decisions to be made when fighting these canopy diseases. An example of those are fungus and Aceria oleae in olive leaves. The study begins with the analysis of a data set generated in the laboratory and divided into healthy and faulty parts. The images were captured with a RGB and a multi-spectral with the blue, green, red, near infrared and red border spectra. They were taken in an image laboratory with a white background and led lighting. The objective was to carry out tests to determine the impact of each spectral channel and the possibility of using different types of cameras for the detection of diseases, as well as important factors to consider for its application in the field. Then, Mask rcnn R 50 FPN 3 was used to obtain segmented leaves and Fast-r cnn inception v2 to detect leaves. Then the detected or segmented leaves were classified with the Inception V3 network to determine which were healthy and which were diseased. With, the combination of these tools, it is possible to determine the disease level of an olive tree in the field.
February 2023
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158 Reads
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10 Citations
Control Engineering Practice
January 2023
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6 Reads
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4 Citations
Intelligent Systems
This chapter explores two basic techniques to design a controller to guide differential drive wheeled robots and quadrotors, namely the single-loop dynamic control system and the inner-outer loops control system, ans shows that they can be adopted to accomplish positioning tasks, trajectory-tracking tasks and path-following tasks, with quite small adaptations. It also shows how to design an adaptive dynamic compensator to be used as the inner control loop, which is quite useful in situations in which the robot transports loads, which changes its dynamic parameters, as well as to compensate for any misidentified dynamic parameter or external disturbances. The focus, in both designs, is the inverse kinematics technique to design the outer loop correspondent to the inner-outer loops structure, and the inverse dynamics technique to design the inner loop of the inner-outer loops structure and the single-loop dynamic controller, which consists in inverting the nonlinear kinematics or dynamics, thus generating a linear closed-loop system equations.
January 2023
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41 Reads
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4 Citations
Intelligent Systems
Two approaches to control a multi robot system, also known as a robot formation or robot cluster, namely the leader-follower and the virtual structure approaches, are dealt with in this chapter. They are discussed in details, and examples showing their implementation to control a group of two or more robots are also discussed, considering groups of two or more robots of the same kinematics and of different kinematics. The scalability of such systems to control more than two or three robots is also addressed. The chapter also discusses how to implement a hierarchical control structure, when regarding conflicting control objectives, showing how to implement a control system taking into account the different priorities assigned to the subtasks involved in the accomplishment of the whole task.
... The camera is located at the bottom of the UAV, as can be seen in Figure 4. More detailed characteristics of the composition of the robot can be seen in [11]. In addition, a unicycle-type robot is used to emulate the moving target. ...
March 2024
Robotics and Autonomous Systems
... Some of the approaches to solving the find-path problem of multitrailer systems given in literature include Virtual Link Tracking Method (VLTM), [17] H-infinity control approach, [18] Modified Transpose Jacobian (MTJ) control method, [19,20] fuzzy control approach, [21] and neural networks. [5] Some of the recent work to address the motion control on-trailer systems include Deng et al.'s distributed three node service scheduling algorithm, [22] Zhao et al.'s configuration estimation and trajectory planning algorithms, [23] Bertolani et al.'s adaptive inner-outer kinematic and dynamic controllers, [24] and Zhao et al.'s two-tier curvature-based path-tracking controller. [25] Moreover, while the control problem of a 1-trailer, 2-trailer and 3-trailer systems are solved using Lyapunov based control scheme (LbCS), [12,13,26,27] there is no general solution (using LbCS) proposed for a n-trailer system. ...
June 2023
Mechatronics
... As new datasets are introduced, researchers can use it to assess the results of existing methodologies and develop new models that perform better on the new data. Overall, new image datasets can help to address existing limitations, reflect new applications, incorporate new features [11,12], and provide opportunities for benchmarking and comparison, all of which can help to advance computer vision research and applications. ...
March 2023
Array
... Multiple aerospace robots for cooperative manipulation and transportation considering the dynamic coupling between the arXiv:2407.08084v1 [cs.RO] 10 Jul 2024 individual subsystems have been widely studied in both space [1][2][3][4] and aerial environments [5,6] in recent decade. ...
July 2023
IEEE Transactions on Control Systems Technology
... This control is informed by the underdriven nature of the system to ensure zero asymptotic convergence of the tracking; however, the experiment itself is subject to external disturbances. In [8], a path following method is proposed with reference to the end-effector of an aerial mobile manipulator. It is shown experimentally that the proposed controller saves about 10% of the energy that would otherwise be expended during such path following activities. ...
February 2023
Control Engineering Practice
... They have been used in applications such as aerial cinematography [3], target tracking [4], load transportation [5][6][7][8], and warehouse operations [9], just to mention a few examples (a more detailed overview of applications involving multirotor aerial robots is available in [10]). Many times such UAVs are used as part of a multirobot system [11,12], either working cooperatively with other UAVs [7] or with unmanned ground vehicles (UGVs), such as in [13][14][15][16], and, in special, in [17,18] and [19]. Notice that in these three last cases the task to be accomplished is an inventory of goods in an automated warehouse, the same task addressed in this paper. ...
January 2023
Intelligent Systems
... Control system researchers have also found a benchmark system in mobile robots since they present highly nonlinear dynamics. An interesting fact is that most of the research on mobile robot control is focused on the consideration of kinematic models and in designing feedback control laws for non-holonomic systems; see, for example, [2]. ...
January 2023
Intelligent Systems
... Figure 7 describes the test arena, consisting of a Linux PC running ROS melodic, which establishes Wi-Fi communication between the control computer and the robot, with the control signals sent to the vehicles at a rate of 30 Hz. As for the controller adopted, it was the kinematic one discussed in [18]. The mission began after the global localization phase, and during it, we applied the local localization algorithm. ...
January 2023
Intelligent Systems
... Dentro de la alta gama de sistemas desarrollados para la recuperación de tobillos, la mayoría de estos sistemas proporcionan los movimientos de inversión/eversión y dorsi/plantar flexión [7,8]. Esta amplia variedad de dispositivos y enfoques ha revolucionado la forma en que se aborda la rehabilitación de las extremidades, permitiendo un enfoque más efectivo y personalizado para cada paciente [9][10][11][12]. La evolución continua en este campo promete seguir mejorando la calidad de vida de quienes buscan recuperar su movilidad y funcionalidad. ...
July 2022
IEEE International Conference on Rehabilitation Robotics : [proceedings]
... Radcliffe et al. (2018) explored the estimation of navigational features using path planes extracted from the combination of the canopy with the background sky. Additionally, Gimenez et al. (2022) demonstrated a trunk detection system for tree crops using RGB-D data, integrated with a structure-based SLAM system to enhance autonomous navigation through regular tree distributions. ...
August 2022
Computers and Electronics in Agriculture