scholarly journals Controlling the PVTOL Aircraft System with an Inverted Pendular Load by means of Nested Saturation Functions and GPI Controller

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Cesar Alejandro Villaseñor Rios ◽  
Octavio Gutiérrez-Frías ◽  
Carlos Aguilar-Ibanez ◽  
Miguel S. Suarez-Castanon
Keyword(s):  
Numerical Simulation ◽  
Linear Transformations ◽  
Control Approach ◽  
Performance Indexes ◽  
Input Control ◽  
Unknown Disturbances ◽  
Position Regulation ◽  
And Performance ◽  
Aircraft System ◽  
The Stability

This paper presents a control scheme that allows height position regulation and stabilization for an unmanned planar vertical takeoff and landing aircraft system with an inverted pendular load. The proposed controller consists of nested saturations and a generalized proportional integral (GPI). The GPI controls the aircraft height and the roll attitude; the latter is used as the fictitious input control. Next, the system is reduced through linear transformations, expressing it as an integrator chain with a nonlinear perturbation. Finally, the nested saturation function-based controller stabilizes the aircraft’s horizontal position and the pendulum’s angle. Obtaining the control approach was a challenging task due to the underactuated nature of the aircraft, particularly ensuring the pendulum’s upright position. The stability analysis was based on the second method of Lyapunov using a simple candidate function. The numerical simulation confirmed the control strategy’s effectiveness and performance. Additionally, the numerical simulation included a comparison against a PD controller, where its corresponding performance indexes were estimated, revealing that our controller had a better response in the presence of unknown disturbances.

Dynamic Analysis and Stability Improvement Concerning the Integration of Wind Farms Kurdistan Electric Network Case Study

2011 ◽  
pp. 198-219 ◽  
Author(s):  
Mohammad Saleh ◽  
Hassan Bevrani
Keyword(s):  
Wind Power ◽  
Dynamic Models ◽  
Wind Farms ◽  
Integrated System ◽  
Electric Network ◽  
Control Approach ◽  
Control Loops ◽  
And Performance ◽  
The Stability

This chapter presents an overview of key issues and technical challenges in a regional electric network, following the integration of a considerable amount of wind power. A brief survey on wind power system, the present status of wind energy worldwide, common dynamic models, and control loops for wind turbines are given. In this chapter, the Kurdistan electric network in the Northwest part of Iran is introduced as a case study system, and an analytical approach is conducted to evaluate the potential of wind power installation, overall capacity estimation, and economic issues, based on the practical data. Then, the impact of high penetration wind power on the system dynamic and performance for various wind turbine technologies is presented. The stability of integrated system is analyzed, and the need for revising of conventional controls and performance standards is emphasized. Finally, a STATCOM-based control approach is addressed to improve the system stability.

scholarly journals Stability of the dynamic shifting process in the vehicle transmission with the input shaper

2018 ◽  
Vol 211 ◽  
pp. 02007 ◽  
Author(s):  
Alexander Taratorkin ◽  
Victor Derzhanskii ◽  
Igor Taratorkin
Keyword(s):  
Numerical Simulation ◽  
Natural Frequency ◽  
Control Algorithm ◽  
Control Law ◽  
Single Node ◽  
Input Shaper ◽  
Inertial Parameters ◽  
Wheel Drive ◽  
And Performance ◽  
The Stability

This paper investigates stability of the dynamic process of gear shift in the vehicle transmission with the input shapers (IS) taking in consideration uncertainty of the natural frequency of the mechanical system. The proposed control algorithm increases the stability of the researched system with variation of its elastic and inertial parameters. The control law with guaranteed asymptotic stability is obtained for full load of the vehicle when the all-wheel drive is turned on. The monitoring of the state and performance of the required parameters for the regulation of input shapers are tested by means of numerical simulation. Analyzing the results it is established that the best stability is reached by the adaptive setting of the input shapers in accordance with controlled value of the natural frequency of the lowest single-node mode.

scholarly journals Adaptive Differential Thrust Methodology for Lateral/Directional Stability of an Aircraft with a Completely Damaged Vertical Stabilizer

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Long K. Lu ◽  
Kamran Turkoglu
Keyword(s):  
Adaptive Control ◽  
Commercial Aircraft ◽  
Control Approach ◽  
Directional Stability ◽  
Fatal Crash ◽  
And Performance ◽  
The Stability ◽  
And Control ◽  
Model Reference Adaptive ◽  
Differential Thrust

This paper investigates the utilization of differential thrust to help a commercial aircraft with a damaged vertical stabilizer in order to regain its lateral/directional stability. In the event of an aircraft losing its vertical stabilizer, the consequential loss of the lateral/directional stability and control is likely to cause a fatal crash. In this paper, an aircraft with a completely damaged vertical stabilizer is investigated, and a unique differential thrust-based adaptive control approach is proposed to achieve a stable flight envelope. The propulsion dynamics of the aircraft is modeled as a system of differential equations with engine time constant and time delay terms to study the engine response time with respect to a differential thrust input. The proposed differential thrust control module is then presented to map the rudder input to differential thrust input. Model reference adaptive control based on the Lyapunov stability approach is implemented to test the ability of the damaged aircraft to track the model aircraft’s (reference) response in an extreme scenario. Investigation results demonstrate successful application of such differential thrust approach to regain lateral/directional stability of a damaged aircraft with no vertical stabilizer. Finally, the conducted robustness and uncertainty analysis results conclude that the stability and performance of the damaged aircraft remain within desirable limits and demonstrate a safe flight mission through the proposed adaptive control methodology.

scholarly journals Robust Full Tracking Control Design of Disturbed Quadrotor UAVs with Unknown Dynamics

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 115 ◽  
Author(s):  
Nabil Nafia ◽  
Abdeljalil El Kari ◽  
Hassan Ayad ◽  
Mostafa Mjahed
Keyword(s):  
Tracking Control ◽  
Adaptive Systems ◽  
Sliding Mode ◽  
Physical Parameters ◽  
Control Law ◽  
Control Approach ◽  
Adaptive Fuzzy ◽  
Unknown Disturbances ◽  
The Stability ◽  
Interval Type

In this study, we develop a rigorous tracking control approach for quadrotor unmanned aerial vehicles (UAVs) with unknown dynamics, unknown physical parameters, and subject to unknown and unpredictable disturbances. In order to better estimate the unknown functions, seven interval type-2-adaptive fuzzy systems (IT2-AFSs) and five adaptive systems are designed. Then, a new IT2 adaptive fuzzy reaching sliding mode system (IT2-AFRSMS) which generates an optimal smooth adaptive fuzzy reaching sliding mode control law (AFRSMCL) using IT2-AFSs is introduced. The AFRSMCL is designed a way that ensures that its gains are efficiently estimated. Thus, the global proposed control law can effectively achieve the predetermined performances of the tracking control while simultaneously avoiding the chattering phenomenon, despite the approximation errors and all disturbances acting on the quadrotor dynamics. The adaptation laws are designed by utilizing the stability analysis of Lyapunov. A simulation example is used to validate the robustness and effectiveness of the proposed method of control. The obtained results confirm the results of the mathematical analysis in guaranteeing the tracking convergence and stability of the closed loop dynamics despite the unknown dynamics, unknown disturbances, and unknown physical parameters of the controlled system.

scholarly journals DEVELOPMENT OF NUMERICAL PLATFORM FOR AIRCRAFT SYSTEMS SIMULATION

INSIST ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 97
Author(s):  
Rianto A Sasongko ◽  
Yorgi A. Ndaomanu ◽  
Yazdi I. Jenie ◽  
M. Luthfi I. Nurhakin ◽  
M. Rafi Hadytama ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Control System ◽  
System Analysis ◽  
System Development ◽  
Landing Gear ◽  
Control Surface ◽  
System Control ◽  
Aircraft Systems ◽  
And Performance ◽  
Aircraft System

This paper discusses the development of a numerical simulation platform that can be used for representing the principal works of aircraft systems. The platform consists of some parts each of which is intended to replicate the operation of a system implemented in a modern aircraft, such as hydraulic line, electrical system, landing gear system, control system, etc. The platform is intended to be a tool for modeling and analyzing the operation and performance of certain systems configuration. To some extend the platform can be viewed as a virtual Iron Bird System. Iron Bird is a term representing a platform for simulating the works of aircraft systems using real components, which is very important for aircraft system development. At this stage, the numerical platform will only involve some sub-systems, namely main hydraulic line, control surface actuation, landing gear, and control system. These sub-systems are chosen to be the basis for further development where other sub-systems will be added and integrated to the platform.Keywords—Aircraft System, Numerical Simulation, System Analysis

scholarly journals Analytical Modeling and Design of Novel Conical Halbach Permanent Magnet Couplings for Underwater Propulsion

2021 ◽  
Vol 9 (3) ◽  
pp. 290
Author(s):  
Yukai Li ◽  
Yuli Hu ◽  
Youguang Guo ◽  
Baowei Song ◽  
Zhaoyong Mao
Keyword(s):  
Permanent Magnet ◽  
Analytical Calculation ◽  
Underwater Propulsion ◽  
Conical Structure ◽  
Torque Analysis ◽  
Dynamic Seal ◽  
And Performance ◽  
The Stability ◽  
Propulsion Unit ◽  
Force Calculation

Permanent magnet couplings can convert a dynamic seal into a static seal, thereby greatly improving the stability of the underwater propulsion unit. In order to make full use of the tail space and improve the transmitted torque capability, a conical Halbach permanent magnet coupling (C-HPMC) is proposed in this paper. The C-HPMC combines multiple cylindrical HPMCs with different sizes into an approximately conical structure. Compared with the conical permanent magnet couplings in our previous work, the novel C-HPMC has better torque performance and is easy to process. The analytical calculation method of transmitted torque of C-HPMC is proposed on the basis of torque calculation of the three common types of HPMCs. The accuracy of the torque calculation of the three HPMCs is verified, and the torque performance of the three HPMCSs of different sizes is compared and discussed. The “optimal type selection” method is proposed and applied in the design of C-HPMC. Finally, on the basis of torque analysis calculation and axial force calculation, a complete flowchart of the design and performance analysis of C-HPMC is described.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

Adaptive attitude-tracking control of spacecraft considering on-orbit refuelling

2020 ◽  
pp. 014233122097313
Author(s):  
Yiqi Xu
Keyword(s):  
Tracking Control ◽  
Closed Loop ◽  
Closed Loop System ◽  
Tracking Errors ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Inertia Model ◽  
And Performance ◽  
Attitude Tracking Control ◽  
The Stability

This paper studies the attitude-tracking control problem of spacecraft considering on-orbit refuelling. A time-varying inertia model is developed for spacecraft on-orbit refuelling, which actually includes two processes: fuel in the transfer pipe and fuel in the tank. Based upon the inertia model, an adaptive attitude-tracking controller is derived to guarantee the stability of the resulted closed-loop system, as well as asymptotic convergence of the attitude-tracking errors, despite performing refuelling operations. Finally, numerical simulations illustrate the effectiveness and performance of the proposed control scheme.

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