scholarly journals Automatic Control Optimization for Large-Load Plant-Protection Quadrotor

2021 ◽  
Vol 11 (9) ◽  
pp. 4058
Author(s):  
Dada Hu ◽  
Zhongcai Pei ◽  
Zhiyong Tang
Keyword(s):  
Attitude Control ◽  
Plant Protection ◽  
Control Algorithms ◽  
Physical Parameters ◽  
Flight Performance ◽  
Large Load ◽  
Control Optimization ◽  
Water Plants ◽  
The Moment ◽  
Quadrotor Unmanned Aerial Vehicles

In this article, methods for the attitude control optimization of large-load plant-protection quadrotor unmanned aerial vehicles (UAVs) are presented. Large-load plant-protection quadrotors can be defined as quadrotors equipped with sprayers and a tank containing a large amount of water or pesticide, allowing the quadrotors to water plants or spray pesticide during flight. Compared to the control of common small quadrotors, two main points need to be considered in the control of large-load plant-protection quadrotors—first, the water in the tank gradually diminishes during flight and the physical parameters change during this process. Second, the size and mass of the rotors are especially large, which greatly slows the response rate of the rotors. We present an extended-state reinforcement learning (RL) algorithm to solve these problems. The moment of inertia (MOI) of the three axes and the dynamic response constant of the rotors are included in the state list of the quadrotor during the training process, so that the controller can learn these changes in the models. The controlling laws are automatically generated and optimized, which greatly simplifies the tuning process compared to those of traditional control algorithms. The controller in this article is tested on a 10 kg class large-load plant-protection quadrotor, and the flight performance verifies the effectiveness of our work.

Flight performance of the LES-8/9 three-axis attitude control system

1980 ◽  
Author(s):  
F. FLOYD ◽  
C. MUCH ◽  
N. SMITH ◽  
J. VERNAU ◽  
J. WOODS
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Flight Performance ◽  
Attitude Control System

Normalized Adaptive Hybrid Control Algorithms for Helicopter Vibration with Variable Rotor Speed

2021 ◽  
Author(s):  
Kai Lang ◽  
Pinqi Xia ◽  
Edward C. Smith ◽  
Lina Shang
Keyword(s):  
Control Algorithm ◽  
Hybrid Control ◽  
Active Vibration Control ◽  
Frame Structure ◽  
Control Algorithms ◽  
Flight Performance ◽  
Rotor Speed ◽  
Frequency Tracking ◽  
Harmonic Control ◽  
Active Vibration

Variable rotor speed technology implemented in a helicopter can improve the flight performance, reduce the required power, and increase the flight speed. However, variable rotor speed changes the frequencies of rotor vibratory loads and may produce helicopter fuselage resonance under the excitation of the rotor vibratory loads. Active vibration control (AVC) has been effectively used in vibration reduction of helicopter fuselages. However, the frequency domain control algorithms that are currently used have poor adaptability in controlling vibration with variable frequencies (i.e., during time varying rotor speeds). In order to effectively improve control convergence, adaptability, and effectiveness, the normalized adaptive hybrid control algorithms containing both the normalized adaptive harmonic control algorithm and the normalized frequency tracking algorithm have been presented in this paper. Simulations of AVC with variable frequencies on a dynamically similar frame structure of a helicopter fuselage driven by piezoelectric stack actuators installed on the gearbox support struts show that the normalized adaptive hybrid control algorithms can accurately track the changes in rotor load frequencies and can be effectively used in the AVC of a helicopter with variable rotor speed.

scholarly journals Foaming Capacity of New Superficial Active Salefied Polyether ( = 3 – 20) Primary Amides in Food Hygienization

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
M. SBANCA ◽  
C. JIANU ◽  
I. JIANU
Keyword(s):  
Plant Protection ◽  
Foam Stability ◽  
Wide Spectrum ◽  
Foaming Agents ◽  
New Class ◽  
Wide Range ◽  
Low Toxicity ◽  
Foaming Capacity ◽  
Water Plants ◽  
Alkaline Catalysis

.Colloidal features [foaming capacity (FC); foam stability (FS) and foam density (FD)] of conditioning auxiliaries (additives) of plant protection active principles constitute, together with toxicity, a decisive technical index in forming administering receipts in modern ecological agriculture and foodstuff processing all during the agroalimentary processing and consumption chain. In this paper we show the results of a study on a new class of superficial active compounds salefied polyether ( = 3 – 20) primary amides. As diderived glymes, they have a guided regulation capacity of the HLB balance through the change of the medium degree of oligomerisation ( ) of the polyoxyethylene chain (PEO). Can thus obtain a wide range of structures such as micellar solute, dispersion, emulsion, and foaming agents, etc., through the cyanoethylation of polyethoxylated nonylphenols with a medium degree of oligomerisation ( ) between 3 and 20 structural oxyethylene units (EO) in alkaline catalysis with monomer acrylonitrile, followed by a classical hydrogenation in heterogeneous catalysis of intermediary nitrile thus obtained, and finally partial hysrolysis and salefied with HCOOH; CH3COOH. These are biodegradable in water plants, which ensure special ecologlcal features and high compatibility within the restrictive legal ensemble of a foodstuff processing integrated in an extremely polluted environment. Structures have real bacteriostatical abilities compared to a wide spectrum of microrganisms (tested in studies related to this paper). Low toxicity of polyoxyethylene chains (PEO) together with that of other structural units in this polyether primary amides provide the studied glymes with a high compatibility in relation to environment and to plant and animal organisms of the food chain.

The control optimization algorithm for automatic braking of a wheeled vehicle

Trudy NAMI ◽  
2021 ◽  
pp. 48-57
Author(s):  
V. O. Strukov
Keyword(s):  
Road Transport ◽  
Practical Significance ◽  
Quadratic Functional ◽  
Valve Body ◽  
Braking System ◽  
Control Optimization ◽  
Wheeled Vehicle ◽  
Developing Directions ◽  
Software And Hardware ◽  
The Moment

Introduction (problem statement and relevance). One of the most promising and intensively developing directions in the automation field of road transport management is the creation of highly automated vehicles.The purpose of the study was to find a way to solve a wheeled vehicle safe automatic braking problem in terms of minimizing quality control of the quadratic functional and work out optimal software and hardware implementation of this system.Methodology and research methods. To solve the problem, the method of the control algorithm analytical design was used, basing on the use of the necessary conditions for minimizing the elements of the functional for the control law synthesis. The maximum deceleration value was due to the identified tire grip, and the deceleration threshold from which braking begins was selected as the minimum of the working deceleration and two decelerations depending on the rear obstacle distance.Scientific novelty and results. The tests of the developed function were carried out for the LADA Vesta vehicle equipped with an ABS valve body with the possibility of programmed control. The analysis of the research results showed that when solving the problem of safe automatic braking in front of an obstacle, the software limitation of braking deceleration did not allow wheel blocking and performed the functions of an anti-lock braking system at the permissible wheel slipping level; software backup of the distance calculation to the front obstacle from the moment of braking start allowed to prevent most of the situations with false data from the radar when the vehicle pecked during braking.Practical significance. Software tuning of mathematical models parameters of the engine, transmission and braking system allows you to adapt the automatic braking system to a wide class of vehicle models.

scholarly journals Surface Abundances of Light Elements as Diagnostics of Transport Processes in the Sun and Solar-type stars

1990 ◽  
Vol 121 ◽  
pp. 437-448
Author(s):  
A. Baglin ◽  
Y. Lebreton
Keyword(s):  
Solar Surface ◽  
Rotation Velocity ◽  
Transport Processes ◽  
Physical Parameters ◽  
The Sun ◽  
Light Elements ◽  
Cosmic Abundance ◽  
Solar Type ◽  
The Moment ◽  
Slow Transport

AbstractObservations of the surface abundances of lithium, beryllium and helium-3 in the Sun and in solar-type stars of different ages should be interpreted in a coherent way. The abundance of lithium at the surface of a star decreases slowly with age; for stars of the same age it decreases with mass and a dependence on the rotation velocity is suggested. The solar surface lithium is depleted by a factor of 100 relative to the cosmic abundance while an He-3 enrichment of 15% at the solar surface during evolution is suggested.Observations favour the hypothesis of a slow transport process at work between the outer convective zone and the radiative interior of these stars. Orders of magnitude of the transport coefficient as well as its dependence upon the physical parameters can be inferred from surface abundances of light elements, but at the moment we are far from producing a completely consistent modelization.

Flight performance of the attitude control system of the balloon experimental twin telescope for infrared interferometry (BETTII)

2018 ◽  
Author(s):  
Jordi Vila Hernández de Lorenzo ◽  
Stephen A. Rinehart ◽  
Georges Nehmetallah ◽  
Stephen Maher ◽  
Maxime Rizzo ◽  
...  
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Flight Performance ◽  
Attitude Control System ◽  
Infrared Interferometry

scholarly journals Dynamic Modeling and Analysis of Spacecraft With Variable Tilt of Flexible Appendages

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Nicolas Guy ◽  
Daniel Alazard ◽  
Christelle Cumer ◽  
Catherine Charbonnel
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Solar Panel ◽  
Physical Parameters ◽  
Attitude Control System ◽  
Multibody Modeling ◽  
Modeling And Analysis ◽  
Complete Revolution ◽  
The Stability ◽  
Flexible Appendages

This article describes a general framework to generate linearized models of satellites with large flexible appendages. The obtained model is parameterized according to the tilt of flexible appendages and can be used to validate an attitude control system over a complete revolution of the appendage. Uncertainties on the characteristic parameters of each substructure can be easily considered by the proposed generic and systematic multibody modeling technique, leading to a minimal linear fractional transformation (LFT) model. The uncertainty block has a direct link with the physical parameters avoiding nonphysical parametric configurations. This approach is illustrated to analyze the attitude control system of a spacecraft fitted with a tiltable flexible solar panel. A very simple root locus allows the stability of the closed-loop system to be characterized for a complete revolution of the solar panel.

scholarly journals Modeling and Control of a Dragonfly-Like Robot

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Micael S. Couceiro ◽  
N. M. Fonseca Ferreira ◽  
J. A. Tenreiro Machado
Keyword(s):  
System Performance ◽  
Computational Simulation ◽  
The Other ◽  
Control Algorithms ◽  
Kinematics And Dynamics ◽  
Flight Performance ◽  
Modeling And Control ◽  
Wing Motion ◽  
Simulation Based ◽  
And Control

Dragonflies demonstrate unique and superior flight performances than most of the other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper, the dynamics of a dragonfly-inspired robot is studied. The system performance is analyzed in terms of time response and robustness. The development of computational simulation based on the dynamics of the robotic dragonfly allows the test of different control algorithms. We study different movements, the dynamics, and the level of dexterity in wing motion of the dragonfly. The results are positive for the construction of flying platforms that effectively mimic the kinematics and dynamics of dragonflies and potentially exhibit superior flight performance than existing flying platforms.

scholarly journals A Novel Concept for Guidance and Control of Spacecraft Orbital Maneuvers

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Matteo Dentis ◽  
Elisa Capello ◽  
Giorgio Guglieri
Keyword(s):  
Attitude Control ◽  
Linear Quadratic Regulator ◽  
Control Algorithms ◽  
Linear Quadratic ◽  
C Language ◽  
Orbital Maneuvers ◽  
Guidance And Control ◽  
Actuation System ◽  
Novel Concept ◽  
And Control

The purpose of this paper is the design of guidance and control algorithms for orbital space maneuvers. A 6-dof orbital simulator, based on Clohessy-Wiltshire-Hill equations, is developed in C language, considering cold gas reaction thrusters and reaction wheels as actuation system. The computational limitations of on-board computers are also included. A combination of guidance and control algorithms for an orbital maneuver is proposed: (i) a suitably designed Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) algorithm is adopted for the guidance and (ii) a linear quadratic regulator (LQR) is used for the attitude control. The proposed approach is verified for different cases, including external environment disturbances and errors on the actuation system.

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