Nonlinear system controllability analysis and autopilot design for bank-to-turn aircraft with two flaps

In this study, the six-degrees-of-freedom flight motion of a tail-controlled bank-to-turn aircraft with two flaps is described as a nonlinear control system. The controllability of this flap-controlled system is analyzed based on nonlinear controllability theory and the system is proved to be weakly controllable. By choosing the angle-of-attack and roll angle as the outputs of this control system, the zero dynamics of the system are analyzed using Lyapunov stability theory, and are proved to be stable under some conditions given by an inequality. Then an autopilot is designed for this system using the feedback linearization technique. Results of the numerical simulation for this control system show the effectiveness of the controllability analysis and autopilot design.

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Adaptive Attitude Control on Multiple Independently Targeted Reentry Vehicles (MIRV)

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.494-495.1316 ◽

2014 ◽

Vol 494-495 ◽

pp. 1316-1319

Author(s):

Xing Yu Chen ◽

Fan Li ◽

Jian Hui Zhao ◽

Zhao Long Fan

Keyword(s):

Numerical Simulation ◽

Control System ◽

Lyapunov Stability ◽

Attitude Control ◽

Stability Theory ◽

Lyapunov Stability Theory ◽

Adaptive Controller ◽

Attitude Dynamics ◽

Dynamics Model ◽

Simulation Results

Based on the characteristics of releasing loads for many times, the attitude dynamics model of MIRV has established by using the Rodrigues representation, and we proposed a method of indirect multi-model adaptive attitude control. It was proved that the adaptive controller we designed can ensure the control system globally uniformly and bounded stable according to the Lyapunov stability theory, and the effectiveness of the controller was demonstrated by the numerical simulation results.

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Development of active six-degrees-of-freedom microvibration control system using giant magnetostrictive actuators

Smart Materials and Structures ◽

10.1088/0964-1726/9/2/308 ◽

2000 ◽

Vol 9 (2) ◽

pp. 175-185 ◽

Cited By ~ 20

Author(s):

Yoshiya Nakamura ◽

Masanao Nakayama ◽

Keiji Masuda ◽

Kiyoshi Tanaka ◽

Masashi Yasuda ◽

...

Keyword(s):

Control System ◽

Degrees Of Freedom ◽

Six Degrees Of Freedom ◽

Magnetostrictive Actuators

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Research on Adaptive Control System of Robot Arm with Six Degrees of Freedom

Proceedings of the 2016 International Conference on Sensor Network and Computer Engineering ◽

10.2991/icsnce-16.2016.129 ◽

2016 ◽

Author(s):

Changgeng Yu ◽

Sunyun Li

Keyword(s):

Adaptive Control ◽

Control System ◽

Degrees Of Freedom ◽

Robot Arm ◽

Adaptive Control System ◽

Six Degrees Of Freedom

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Numerical Simulation of Ship-Ship Interactions in Waves

Volume 2: CFD and FSI ◽

10.1115/omae2019-95737 ◽

2019 ◽

Author(s):

Xueshen Xie ◽

Yuxiang Wan ◽

Qing Wang ◽

Hao Liu ◽

Dakui Feng

Keyword(s):

Numerical Simulation ◽

Degrees Of Freedom ◽

Simulation Analysis ◽

Turbulence Models ◽

Body Motion ◽

Structured Grid ◽

Six Degrees Of Freedom ◽

Unsteady Rans ◽

Small Ship ◽

The Impact

Abstract A numerical simulation of the hydrodynamic interaction and attitude of a ship and two ships of different sizes navigating in parallel in waves were carried out in this paper. The study of the two ships navigating in parallel is of great significance in marine replenishment. This paper used in house computational fluid dynamics (CFD) code to solve unsteady RANS equation coupled with six degrees of freedom (6DOF) solid body motion equations. URANS equations are solved by finite difference method and PISO algorithm. Structured grid with overset technology have been used to make computations. Turbulence models used the Shear Stress Transport (SST) k-ω model. The method used for free surface simulation is single phase level set. In this paper, two DTMB 5415 with different scales are selected for simulation analysis. This paper analyzed the impact of the big ship on the small ship when the two ships were navigating in parallel. This paper also analyzed the relationship between interaction and velocity between hulls, which has certain guiding significance for the ship’s encounter on the sea.

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Numerical Simulation of Submarine Surfacing With Six Degrees of Freedom in Regular Waves

Volume 7: Ocean Engineering ◽

10.1115/omae2016-55018 ◽

2016 ◽

Author(s):

Weijian Jiang ◽

Zhilin Wang ◽

Ran He ◽

Xianzhou Wang ◽

Dakui Feng

Keyword(s):

Numerical Simulation ◽

Wave Height ◽

Velocity Fluctuation ◽

Degrees Of Freedom ◽

Wave Length ◽

Roll Angle ◽

Regular Waves ◽

Rolling Moment ◽

Six Degrees Of Freedom ◽

Calm Water

Submarine surfacing in waves is three dimensional unsteady motion and includes complex coupling between force and motion. This paper uses computational fluid dynamics (CFD) to solve RANS equation with coupled six degrees of freedom solid body motion equations. RANS equations are solved by finite difference method and PISO arithmetic. Level-set method is used to simulate the free surface. Computations were performed for the standard DARPA SUBOFF model. The structured dynamic overset grid is applied to the numerical simulation of submarine surfacing (no forward speed) in regular waves and computation cases include surfacing in the calm water, transverse regular waves with different ratio of wave height and submarine length (h/L = 0.01, 0.02, 0.03, 0.04) and transverse regular waves with different ratio of wave length and submarine length (λ/L = 0.5, 1, 1.5). The asymmetric vortices in the process of submarine surfacing can be captured. It proves that roll instability is caused by the destabilizing hydrodynamic rolling moment overcoming the static righting moment both under the water and in regular waves. Relations among maximum roll angle, surfacing velocity fluctuation and wave parameters are concluded by comparison with variation trend of submarine motion attitude and velocity of surfacing in different wave conditions. Simulation results confirm that wave height h/L = 0.04 and wave length λ/L = 1.5 lead to surfacing velocity fluctuation significantly. Maximum roll angle increases with the increase of wave height and wave length. Especially the law presents approximate linear relationship. Maximum roll angle with wave height (h/L = 0.04) can reach to 7.29° while maximum roll angle with wave length (λ/L = 1.5) can reach to 5.79° by contrast with 0.85° in calm water. According to the above conclusions, maneuverability can be guided in the process of submarine surfacing in waves in order to avoid potential safety hazard.

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An Autonomous Underwater Vehicle for Competition

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.380-384.595 ◽

2013 ◽

Vol 380-384 ◽

pp. 595-600

Author(s):

Hai Tian ◽

Bo Hu ◽

Can Yu Liu ◽

Guo Chao Xie ◽

Hui Min Luo

Keyword(s):

Control System ◽

Hydrodynamic Model ◽

Degrees Of Freedom ◽

Autonomous Underwater Vehicle ◽

Autonomous Underwater Vehicles ◽

Vertical Motion ◽

Underwater Vehicle ◽

Step Response ◽

Six Degrees Of Freedom ◽

Simulink Simulation

The research of this paper was derived from the small autonomous underwater vehicle (AUV)Raider well performed in the 15th International Underwater Vehicle Competition (IAUVC),San Diego. In order to improve the performance of underwater vehicle, the control system of performance motion played an important role on autonomous underwater vehicles stable motion, and the whole control system of AUV is the main point. Firstly, based on the motion equations of six degrees of freedom, the paper simplified the dynamical model reasonably in allusion; Due to the speed of Raider to find the target was very low, this paper considered the speed was approximately zero and only considered the vertical motion. Therefore, this paper established the vertical hydrodynamic model of Raider, obtaining the transfer equation of vertical motion. Through the experiment and Matlab/Simulink simulation, this paper got the actual depth of the step response curve and simulation curve, and verified the validity of the vertical hydrodynamic model and the correlation coefficient.

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Numerical simulation of h-adaptive immersed boundary method for freely falling disks

Modern Physics Letters B ◽

10.1142/s021798491840002x ◽

2018 ◽

Vol 32 (12n13) ◽

pp. 1840002

Author(s):

Pan Zhang ◽

Zhenhua Xia ◽

Qingdong Cai

Keyword(s):

Numerical Simulation ◽

Numerical Model ◽

Aspect Ratio ◽

Immersed Boundary Method ◽

Adaptive Mesh Refinement ◽

Degrees Of Freedom ◽

Adaptive Mesh ◽

Immersed Boundary ◽

Six Degrees Of Freedom ◽

Boundary Method

In this work, a freely falling disk with aspect ratio 1/10 is directly simulated by using an adaptive numerical model implemented on a parallel computation framework JASMIN. The adaptive numerical model is a combination of the h-adaptive mesh refinement technique and the implicit immersed boundary method (IBM). Our numerical results agree well with the experimental results in all of the six degrees of freedom of the disk. Furthermore, very similar vortex structures observed in the experiment were also obtained.

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MPC Based Feedback-Linearization Strategy of a Fixed-Wing UAV

10.48011/asba.v2i1.1263 ◽

2020 ◽

Author(s):

Leonardo A. A. Pereira ◽

Luciano C. A. Pimenta ◽

Guilherme V. Raffo

Keyword(s):

Predictive Control ◽

Control Strategy ◽

Feedback Linearization ◽

Degrees Of Freedom ◽

Vehicle Control ◽

Control Allocation ◽

Linearization Technique ◽

Aerial Vehicle ◽

The Relationship ◽

Curve Tracking

This work proposes a xed-wing UAV (Ummaned Aerial Vehicle) control strategy based on feedback-linearization and model predictive control (MPC). The strategy makes use of the relationship between the applied control inputs of the UAV and the generalized forces and moments actuating on it. A linear model is obtained by the exact feedback-linearization technique, followed by the use of MPC to solve the trajectory tracking and the control allocation problems. The proposed controller is capable of actuating on the 6 DOF (Degrees of Freedom) of the UAV, avoiding inherited restrictions when the model is decoupled. The proposed strategy is applied in a curve tracking task. Simulations are performed using MATLAB software, and the results show the eciency of the proposed control strategy.

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