scholarly journals Quadrotor Unmanned Aerial Vehicles: Visual Interface for Simulation and Control Development

2021 ◽  
Author(s):  
Manuel A. Rendón

Quadrotor control is an exciting research area. Despite last years developments, some aspects demand a deeper analysis: How a quadrotor operates in challenging trajectories, how to define trajectory limits, or how changing physical characteristics of the device affects the performance. A visual interface development platform is a valuable tool to support this effort, and one of these tools is briefly described in this Chapter. The quadrotor model uses Newton-Euler equations with Euler angles, and considers the effect of air drag and propellers’ speed dynamics, as well as measurement noise and limits for propeller speeds. The tool is able to test any device just by setting a few parameters. A three-dimensional optimal trajectory defined by a set of waypoints and corresponding times, is calculated with the help of a Minimum Snap Trajectory planning algorithm. Small Angle Control, Desired Thrust Vector (DTV) Control and Geometric Tracking Control are the available strategies in the tool for quadrotor attitude and trajectory following control. The control gains are calculated using Particle Swarm Optimization. Root Mean Square (RMS) error and Basin of Attraction are employed for validation. The tool allows to choose the control strategy by visual evaluation on a graphical user interface (GUI), or analyzing the numerical results. The tool is modular and open to other control strategies, and is available in GitHub.

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2358 ◽  
Author(s):  
Omar Mohamed ◽  
Ashraf Khalil

This paper reviews the modeling techniques and control strategies applied to gas turbine power generation plants. Recent modeling philosophies are discussed and the state-of-the-art feasible strategies for control are shown. Research conducted in the field of modeling, simulation, and control of gas turbine power plants has led to notable advancements in gas turbines’ operation and energy efficiency. Tracking recent achievements and trends that have been made is essential for further development and future research. A comprehensive survey is presented here that covers the outdated attempts toward the up-to-date techniques with emphasis on different issues and turbines’ characteristics. Critical review of the various published methodologies is very useful in showing the importance of this research area in practical and technical terms. The different modeling approaches are classified and each category is individually investigated by reviewing a considerable number of research articles. Then, the main features of each category or approach is reported. The modern multi-variable control strategies that have been published for gas turbines are also reviewed. Moreover, future trends are proposed as recommendations for planned research.


2004 ◽  
Vol 16 (03) ◽  
pp. 157-164 ◽  
Author(s):  
HAO-LING CHEN ◽  
TUNG-WU LU ◽  
H. C. LIN

A better understanding of the kinematics and control strategies adopted during obstacle crossing is essential for the prevention of injuries associated with falls in the elderly. The effects of obstacle height on the foot clearance, foot-obstacle distance and joint kinematics have presented significant controversy. This may be related to the selection of obstacle height, whether the obstacles are normalized to the leg length, and to the calculation of the foot-obstacle clearance, as well as the extraction of representative joint angles for the analysis. In this study, fourteen young healthy adults wearing 28 infrared retroreflective markers walked and crossed obstacles of heights of 0%, 10%, 20% and 30% of their leg lengths in a gait laboratory equipped with a 3D motion analysis system. Three-dimensional joint kinematics of the lower limb were calculated. Foot clearances were calculated using the heel and toe markers. The results suggested that young subjects maintained a constant margin of leading foot clearance when crossing higher obstacles (higher than 79.4mm) and a constant trailing foot clearance for all obstacle heights. Both toe-obstacle and heel-obstacle horizontal distances were not affected by obstacle height. Apart from the peak values, kinematic variables for the leading limb should be considered both when the toe and heel cross the obstacle while only those when the toe crosses the obstacle for the trailing limb. Not only in the sagittal plane, motions of the lower limb in the other two planes were also important when investigating the kinematics of the leading limb during obstacle crossing. The present study clarified some of the controversies in the literature of obstacle-crossing through careful comparisons of kinematic variables obtained from different study aspects. The results will be helpful for future studies to gain insight into the kinematics and control strategies adopted during obstacle-crossing.


Author(s):  
Keisuke Arikawa

We investigate various algorithms for analyzing the characteristics of the internal motion of proteins based on the analogies between their kinematic structures and robotic mechanisms. First, we introduce an artificial simple protein model, planar main chain (PMC), composed of a planar serial link mechanism to investigate the algorithms. Then, we develop algorithms for analyzing the conformational fluctuations by applying the manipulability analysis of robot manipulators and control strategies for redundant manipulators. Next, we develop algorithms for analyzing the conformational deformation caused by the external forces and to evaluate the compliances of the specified parts of proteins. Finally, we show that the proposed algorithms developed by using PMC models are applicable for the three dimensional main chain structures of real proteins, and may be used to analyze their characteristics of the internal motion. We also reveal some preliminary simulation results of the analysis of a real protein.


Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Alvaro Ortiz ◽  
Sergio Garcia-Nieto ◽  
Raul Simarro

Guidance, navigation, and control system design is, undoubtedly, one of the most relevant issues in any type of unmanned aerial vehicle, especially in the case of military missions. This task needs to be performed in the most efficient way possible, which involves trying to satisfy a set of requirements that are sometimes in opposition. The purpose of this article was to compare two different control strategies in conjunction with a path-planning and guidance system with the objective of completing military missions in the most satisfactory way. For this purpose, a novel dynamic trajectory-planning algorithm is employed, which can obtain an appropriate trajectory by analyzing the environment as a discrete 3D adaptive mesh and performs a softening process a posteriori. Moreover, two multivariable control techniques are proposed, i.e., the linear quadratic regulator and the model predictive control, which were designed to offer optimal responses in terms of stability and robustness.


2004 ◽  
Vol 127 (4) ◽  
pp. 537-549 ◽  
Author(s):  
Jason M. Stevens ◽  
Gregory D. Buckner

During the past 20years, tremendous advancements have been made in the fields of minimally invasive surgery (MIS) and minimally invasive, robotically assisted (MIRA) cardiac surgery. Benefits from MIS include reduced pain and trauma, reduced risks of post-operative complications, shorter recovery times, and more aesthetically pleasing results. MIRA approaches have extended the capabilities of MIS by introducing three-dimensional vision, eliminating hand tremors, and enabling the precise articulation of smaller instruments. These advancements come with their own drawbacks, however. Robotic systems used in MIRA cardiac procedures are large, costly, and do not offer the miniaturized articulation necessary to facilitate tremendous advancements in MIS. This paper demonstrates that miniature actuation can overcome some of the limitations of current robotic systems by providing accurate, repeatable control of a small end effector. A 10× model of a two link surgical manipulator is developed, using antagonistic shape memory alloy wires as actuators, to simulate motions of a surgical end-effector. Artificial neural networks are used in conjunction with real-time visual feedback to “learn” the inverse system dynamics and control the manipulator endpoint trajectory. Experimental results are presented for indirect, on-line learning and control. Manipulator tip trajectories are shown to be accurate and repeatable to within 0.5mm. These results confirm that SMAs can be effective actuators for miniature surgical robotic systems, and that intelligent control can be used to accurately control the trajectory of these systems.


2020 ◽  
Author(s):  
Daniel Poremski ◽  
Sandra Henrietta Subner ◽  
Grace Lam Fong Kin ◽  
Raveen Dev Ram Dev ◽  
Mok Yee Ming ◽  
...  

The Institute of Mental Health in Singapore continues to attempt to prevent the introduction of COVID-19, despite community transmission. Essential services are maintained and quarantine measures are currently unnecessary. To help similar organizations, strategies are listed along three themes: sustaining essential services, preventing infection, and managing human and consumable resources.


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