Modeling and Design of an Aircraft-Mode Controller for a Fixed-Wing VTOL UAV

Vertical takeoff and landing (VTOL) is an essential feature of unmanned aerial vehicles (UAVs). On the one hand, VTOL can expand and enhance the applications of UAVs; yet, on the other hand, it makes the design of control systems for UAVs more complicated. The most challenging demand in designing the control system is to achieve satisfactory response sharpness of fixed-wing UAVs to control commands and ensure that the aircraft mode channels are effectively decoupled. In this work, a six-degree-of-freedom (6-DoF) model with forces and moments is established based on the aerodynamic analysis, which is carried out through computational fluid dynamics (CFD) numerical simulation. The improved proportional derivative (PD) controller based on the extended state observer (ESO) is proposed to design the inner-loop attitude control, which increases the anti-interference ability for internal and external uncertainty of the UAV system. The motion equations of the UAV are established and divided into independent components of longitudinal and lateral motion to design the outer loop control law under minor disturbance conditions. A total energy control system (TECS) for the longitudinal height channel is proposed, which separates speed control and track control. L1 nonlinear path tracking guidance algorithm is used for lateral trajectory tracking so as to improve curve tracking ability and wind resistance. Effectiveness of this approach is proved by actual flight experiment data. Finally, a controller based on angular velocity control is designed to prevent the attitude and head reference system (AHRS) from malfunctioning. Its effectiveness is verified by the response test of the control system.

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Assessment of the Quality of the IDT Elemental Observations

Highlights of Astronomy ◽

10.1017/s1539299600009345 ◽

1992 ◽

Vol 9 ◽

pp. 414-414

Author(s):

M.A.C. Perryman

Keyword(s):

Control System ◽

Data Analysis ◽

Attitude Control ◽

Angular Separation ◽

Attitude Control System ◽

Phase Measurements ◽

One Dimensional ◽

The One ◽

Comparison Of The Results

AbstractThe quasi-simultaneous measurement of the one-dimensional angular separation of stars on the sky, on both small and large angular scales, rely on the measurements made by the IDT detector, as well as on inputs from the star mapper and attitude control system. This presentation will concentrate on the results of a comparison of the results of the IDT data processing carried out by the FAST and NDAC data analysis teams. The extent to which the intensity and phase measurements agree between the two reductions, and the extent to which the differences are consistent with expected photon noise errors, will be illustrated.

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Tilt-Rotor Quadrotor Control System Design and Mobile Object Tracking

Mekhatronika Avtomatizatsiya Upravlenie ◽

10.17587/mau.20.629-639 ◽

2019 ◽

Vol 20 (10) ◽

pp. 629-639

Author(s):

M. Shavin ◽

D. Pritykin

Keyword(s):

Control System ◽

Attitude Control ◽

Unscented Kalman Filter ◽

Mobile Object ◽

Main Body ◽

Control Parameters ◽

Control Loop ◽

Motor Speed ◽

The One ◽

And Control

We design the navigation and control system for unmanned aerial vehicle (UAV) with four tilting rotors. The considered UAV implements the so-called X-sceme, which implies the main body and four symmetrical beams, upon which rotors with propellers are mounted. It is different from the classical quadrotor by having four additional servomotors that may change the orientation of the rotors with respect t the main body, thus increasing the control parameters number. Greater number of the actuators in the system, on the one hand, opens new venues for UAVs’ applications but, on the other hand, makes the mathematical model of the UAV’s dynamics quite complicated. The latter calls for new control algorithms to be developed. We start by forming the mathematical models of the UAV’s dynamics. It is shown that the introduction of the tilting motors allows implementing independent control of the quadrotor’s position and attitude. The control loop is designed on the base on the analytical dynamics inversion. The expressions for the control parameters thus obtained are subjected to the numerical analysis, which allows taking into account technical constraints for maximal motor speed and tilt angles. Feedback in the control loop is implemented by simulation of the on-board sensors’ signals, whose characteristics correspond to those of the sensors used in the UAV’s experimental prototype design. The signals are processed with the aid of the unscented Kalman filter algorithm. The results of numerical experiments corroborate the efficiency of the developed control and navigation algorithms. The mission simulated in the numeric experiments is tracking of a pre-defined trajectory and pointing with a body-fixed camera at a mobile object, which, in turn, moves along a programmed trajectory.The results of the numeric experiments show that the UAV is capable of performing complex maneuvers with independent position and attitude control.

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Science Observations with the IUE Using the One Gyro Mode

International Astronomical Union Colloquium ◽

10.1017/s0252921100077587 ◽

1990 ◽

Vol 123 ◽

pp. 517-520

Author(s):

C. Imhoff ◽

R. Pitts ◽

R. Arquilla ◽

C. Shrader ◽

M. Perez ◽

...

Keyword(s):

Control System ◽

Attitude Control ◽

European Space Agency ◽

Attitude Control System ◽

Sun Sensor ◽

Space Agency ◽

Current Attitude ◽

International Ultraviolet Explorer ◽

The One ◽

Science Instrument

AbstractThe International Ultraviolet Explorer (IUE) is a geosynchronous orbiting telescope launched by the National Aeronautics and Space Administration (NASA) on January 26, 1978, and operated jointly by NASA and the European Space Agency. The science instrument consists of two spectrographs which span the wavelength range of 1150 to 3200 Å and offer two dispersions with resolutions of 6 Å and 0.2 Å. The spacecraft’s attitude control system originally included an inertial reference package containing 6 gyroscopes for 3-axis stabilization. The science instrument includes a prime and redundant Field Error Sensor (FES) camera for target aquisition and offset guiding. Since launch, 4 of the 6 gyroscopes have failed. The current attitude control system utilizes the remaining 2 gyros and a Fine Sun Sensor (FSS) for 3-axis stabilization. When the next gyro fails, a new attitude control system will be uplinked which will rely on the remaining gyro and the FSS for general 3-axis stabilzation. In addition to the FSS, the FES cameras will be required to assist in maintaining fine attitude control during target aquisition. This has required thoroughly determining the characteristics of the FES cameras and the spectrograph aperture plate as well as devising new target acquisition procedures. The results of this work are presented.

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Study on Attitude Control of a Cabin-Suspended Catamaran by Using a Double-Loop Control System

Volume 9: Rodney Eatock Taylor Honoring Symposium on Marine and Offshore Hydrodynamics; Takeshi Kinoshita Honoring Symposium on Offshore Technology ◽

10.1115/omae2019-95827 ◽

2019 ◽

Author(s):

Jialin Han ◽

Sota Kanno ◽

Akito Mochizuki ◽

Daisuke Kitazawa ◽

Teruo Maeda ◽

...

Keyword(s):

Control System ◽

Attitude Control ◽

Open Loop ◽

Bench Test ◽

Double Loop ◽

Rotational Angle ◽

Loop Control ◽

Small Vessels ◽

Head Waves ◽

Loop Control System

Abstract A series of cabin-suspended ships, named Wave Harmonizer, has been developed since 2008. The model ship consists of cabin part, hull part and conjunction part which is mounted in-between the cabin and the hull. The possibility and feasibility of introducing suspensions into small vessels are investigated. Effectiveness evaluations are made in two aspects: motion reduction of the cabin and wave energy harvesting through the oscillating cabin. According to the research results obtained in 2015 and 2016, it was found that the deck of the cabin may bear obvious inclination while weights were loading or unloading from it. Moreover, in relative long waves, the effectiveness of the motion reduction of the skyhook controller was insufficient. To solve those problems, an attitude control strategy is proposed. It is adopted as an outer-loop of the existing controller. Inclination sensors are employed to collect the rotational angle of the cabin in terms of pitch and roll. After finishing the design and construction of the double-loop control system, open loop tests are carried out in dry and wet conditions. The chain mechanism of the ship is investigated. Then a bench test is operated to validate the control concept and performance of the double-loop control system. Finally, tank tests are implemented to examine the inclination reduction of the cabin at regular head waves. In this paper, the development of the double-loop control system is described, experimental results are demonstrated with respect to the heave and pitch motion reduction of the cabin at the condition of with/without the outer control loop. It shows that the inclination reduction at the loading/unloading condition and the walking-on-deck condition are significant. However, in waves the effectiveness is not clearly verified. It suggests that the influence of the apparent gravity on the inclination measurement in waves should be investigated and solutions to accurately detect the inclination of the cabin should be sought.

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Geometric Adaptive Controls of a Quadrotor UAV with Decoupled Attitude Dynamics

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4052714 ◽

2021 ◽

Author(s):

Kanishke Gamagedara ◽

Taeyoung Lee

Keyword(s):

Control System ◽

Attitude Control ◽

Position Tracking ◽

Control Input ◽

Attitude Dynamics ◽

Attitude Control System ◽

Adaptive Controls ◽

Local Coordinates ◽

Aerial Vehicle ◽

The One

Abstract This paper presents a geometric adaptive position tracking control system for a quadrotor unmanned aerial vehicle. In particular, the attitude control system is designed on the product of the two-dimensional unit sphere and the one-dimensional circle such that the direction of the thrust that is critical for position tracking is controlled independently from the yawing direction that is irrelevant to the position dynamics. Compared against the prior work with coupled attitude controls on the special orthogonal group, the proposed controller prevents large yaw errors from causing an undesirable performance degradation in tracking a position command. Further, the control input is augmented with adaptive control terms to mitigate the effects of disturbances, and it is formulated globally on the spheres to avoid singularities and complexities of local coordinates. The efficacy of the proposed control system is illustrated by both numerical examples and indoor/outdoor flight experiments.

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