Periodic Optimal Trajectories with Singular Control for Aircraft with High Aerodynamic Efficiency

This paper focuses on fast terminal sliding mode fault-tolerant control for a class of n-order nonlinear systems. Firstly, when the actuator fault occurs, the extended state observer (ESO) is used to estimate the lumped uncertainty and its derivative of the system, so that the fault boundary is not needed to know. The convergence of ESO is proved theoretically. Secondly, a new type of fast terminal sliding surface is designed to achieve global fast convergence, non-singular control law and chattering reduction, and the Lyapunov stability criterion is used to prove that the system states converge to the origin of the sliding mode surface in finite time, which ensures the stability of the closed-loop system. Finally, the effectiveness and superiority of the proposed algorithm are verified by two simulation experiments of different order systems.

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Ergodic control of diffusions with random intervention times

Journal of Applied Probability ◽

10.1017/jpr.2020.80 ◽

2021 ◽

Vol 58 (1) ◽

pp. 1-21

Author(s):

Harto Saarinen ◽

Jukka Lempa

Keyword(s):

Optimal Solution ◽

Singular Control ◽

Control Policy ◽

Control Problems ◽

Ergodic Control ◽

Linear Diffusion ◽

One Dimensional ◽

And Diffusion ◽

Independent Poisson Process ◽

Exact Amount

AbstractWe study an ergodic singular control problem with constraint of a regular one-dimensional linear diffusion. The constraint allows the agent to control the diffusion only at the jump times of an independent Poisson process. Under relatively weak assumptions, we characterize the optimal solution as an impulse-type control policy, where it is optimal to exert the exact amount of control needed to push the process to a unique threshold. Moreover, we discuss the connection of the present problem to ergodic singular control problems, and illustrate the results with different well-known cost and diffusion structures.

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Hydrodynamics can determine the optimal route for microswimmer navigation

Communications Physics ◽

10.1038/s42005-021-00522-6 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Abdallah Daddi-Moussa-Ider ◽

Hartmut Löwen ◽

Benno Liebchen

Keyword(s):

Flow Field ◽

Hydrodynamic Interactions ◽

Optimal Trajectories ◽

Optimal Route ◽

Active Particles ◽

Navigation Strategy ◽

Navigation Strategies

AbstractAs compared to the well explored problem of how to steer a macroscopic agent, like an airplane or a moon lander, to optimally reach a target, optimal navigation strategies for microswimmers experiencing hydrodynamic interactions with walls and obstacles are far-less understood. Here, we systematically explore this problem and show that the characteristic microswimmer-flow-field crucially influences the navigation strategy required to reach a target in the fastest way. The resulting optimal trajectories can have remarkable and non-intuitive shapes, which qualitatively differ from those of dry active particles or motile macroagents. Our results provide insights into the role of hydrodynamics and fluctuations on optimal navigation at the microscale, and suggest that microorganisms might have survival advantages when strategically controlling their distance to remote walls.

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VAGADRONE: Intelligent and Fully Automatic Drone Based on Raspberry Pi and Android

Applied Sciences ◽

10.3390/app11073153 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3153

Author(s):

Saifeddine Benhadhria ◽

Mohamed Mansouri ◽

Ameni Benkhlifa ◽

Imed Gharbi ◽

Nadhem Jlili

Keyword(s):

Remote Control ◽

Autonomous Navigation ◽

Object Identification ◽

External Control ◽

Raspberry Pi ◽

Optimal Trajectories ◽

Live Streaming ◽

Wide Range ◽

Fully Automatic ◽

Direct Use

Multirotor drones are widely used currently in several areas of life. Their suitable size and the tasks that they can perform are their main advantages. However, to the best of our knowledge, they must be controlled via remote control to fly from one point to another, and they can only be used for a specific mission (tracking, searching, computing, and so on). In this paper, we intend to present an autonomous UAV based on Raspberry Pi and Android. Android offers a wide range of applications for direct use by the UAV depending on the context of the assigned mission. The applications cover a large number of areas such as object identification, facial recognition, and counting objects such as panels, people, and so on. In addition, the proposed UAV calculates optimal trajectories, provides autonomous navigation without external control, detects obstacles, and ensures live streaming during the mission. Experiments are carried out to test the above-mentioned criteria.

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