Landing Of Unmanned Aerial Vehicle Research Articles

Automatic Landing Controller of Unmanned Aerial Vehicle

This paper presents the soft control strategies for automatic landing of Unmanned Aerial Vehicle and simulation the result of controller. The soft controller parameters can be modify and show off the results response of control surface of Unmanned Aerial Vehicle which can fly to the desirable waypoints along the flight plan, one may freely select a control scheme to stabilize and perform the target tracking with robustness. The main control system of Unmanned Aerial Vehicle is developed from Fuzzy PD+I controller with auto-tuning gain parameters and the simulation is carried out by Matlab/Simulink simulation program including with Aerosim toolbox software. The model of Unmanned Aerial Vehicle for simulation in this paper is selected the model of Aerosonde UAV from Aerosonde PTY LTD., which is developed mathematical model by Unmanned Dynamics.

Multi-information Based Safe Area Step Selection Algorithm for UAV’s Emergency Forced Landing

In order to solve the problem of forced landing in emergency for Unmanned Aerial Vehicles (UAVs), a multi-information based algorithm for selecting forced landing area by step is proposed. In order to extract the slowly varying edges and weak edges in an aerial image, this algorithm adopted improved edge detection method to detect landing area without obstacles. To select the detected safe areas which are suitable for landing in terms of size and shape, four masks with adequate coverage were designed. The elevation data of the areas were acquired to analyze its terrain. By extracting features of color and texture based on Gray Level Co-Occurrence Matrix (GLCM), fast classification and recognition of landing areas was carried out based on Support Vector Machine (SVM) classifier. Simulation results show that the algorithm, comparing with Bayesian classifier, presents a more fast and accurate classification and selection of the landing areas, fulfilling the demand of forced landing for UAVs in emergency.

A Roadmap for Automated Power Line Inspection. Maintenance and Repair

Electrical power companies usually perform regular visual inspection to check the status of their transmission lines mainly using helicopter equipped with external gimbals housing infrared and ultraviolet camera to detect hot spots and corona discharges. This solution is quite expensive, dangerous for the crew and not very reliable. Focus of this paper is, presenting the state of the art of the most important current projects concerning the two main categories of robots offering a solution of automation, vertical take-off and landing (VTOL) unmanned aerial vehicles (UAVs) and rolling on wires robots (RWR), to create a simple roadmap that can guide researchers and industries in the implementation of a “FULLY AUTOMATED LIVE LINE POWER LINE INSPECTION CONCEPT”: a rigorous live line inspection strategy based on a completely autonomous mobile platform capable of a meaningful payload and a power line data management system including specific tool for image and signal data processing to automatically detect defects or abnormal conditions.

面向无人机自主导航的立体匹配算法

Autonomous navigation is of great significance for information access and landing of unmanned aerial vehicle (UAV). It is the inevitable trend of UAV development. As an excellent image navigation technology, stereo vision can provide critical information for UAV autonomous navigation. The existing stereo matching algorithms reach a low matching accuracy in amplitude distortion images. For the mismatch problem caused by Census transform, a joint matching algorithm consisting of Census transforms and image color information is proposed in this paper. At the same time, the orthogonal integration method is used to raise the speed according to our theory analysis. First, the initial matching cost is constructed by combining the Census transform and color information. Second, the matching cost is aggregated in an improved adaptive window and we use the orthogonal integration method to raise the speed. Finally, after the optimization and re nement, the disparity map can be acquired. The experimental results demonstrate that our method is of higher accuracy by 40% 50% compared with the Census transform method or the image gray information method. The calculation speed has risen by 3 to 12 times. It is robust to the amplitude distortion image and the method can be used in the UAV autonomous navigation very well.

Dynamic Analysis of a Ducted Fan UAV in Forward Flight

This paper deals with the dynamic modeling of a ducted fan vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) and focuses on the dynamic characteristics analyzing in forward flight. A 6-DOF nonlinear model has been established in terms of the forces and moments and the model can be used in the structure and control system design.

Broadband Omnidirectional and Miniature Fold-up Discone Antenna in VHF/UHF Band

In this article, a novel miniature broadband omnidirectional antenna is proposed. This antenna is suitable to use in vehicles, especially in unmanned aerial vehicles, since it will be folded in order to reduce its size when the unmanned aerial vehicle lands. A special kind of wire discone antenna is chosen to achieve all desired goals. Passive broadband impedance matching at the input of the antenna improves the voltage standing-wave ratio. A telescopic fiberglass axis is used in the antenna structure in order to reduce size and increase wind resistance. The assessment of the novel structure in implementing the antenna is confirmed by experimental measurements. The measurement results reveal the preference of the new techniques over the existing approaches, showing voltage standing-wave ratio better than 2.1 and gain between −5.9 and 2 dBi in a total band of 30–500 MHz.

THE CONDITIONS OF PREDICTION OF THE PARAMETRIC COMPONENTS OF THE TERMINATION CONTROL SYSTEM OF THE UNMANNED AERIAL VEHICLE FLIGHT PATH

Abstract. According to the results of measurements on board of Unmanned Aerial Vehicle the distancevector D is formed in the inertial coordinate system, and in mathematical modeling - in the Greenwichsystem of coordinates. The velocity vector k V is formed by the navigation system in the trajectory coordinatesystem. Defined by this way the initial conditions gives the possibility to predict the terminal parameters offlight (descent) of Unmanned Aerial Vehicle.Keywords: control system of the unmanned aerial vehicle flight path and landing, motion parameters,termination control.

Landing a VTOL Unmanned Aerial Vehicle on a Moving Platform Using Optical Flow

This paper presents a nonlinear controller for a vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) that exploits a measurement optical flow to enable hover and landing control on a moving platform, such as, for example, the deck of a sea-going vessel. The VTOL vehicle is assumed to be equipped with a minimum sensor suite [i.e., a camera and an inertial measurement unit (IMU)], manoeuvring over a textured flat target plane. Two different tasks are considered in this paper. The first concerns the stabilization of the vehicle relative to the moving platform that maintains a constant offset from a moving reference. The second concerns regulation of automatic vertical landing onto a moving platform. Rigorous analysis of system stability is provided, and simulations are presented. Experimental results are provided for a quadrotor UAV to demonstrate the performance of the proposed control strategy.

Head‐tilt and pilot fatigue measured by flight simulation

PurposeThe purpose of this paper is to define and determine quantifiable measurements for head‐tilt and pilot fatigue by detecting and measuring the six degrees of freedom (6DOF) head motion of test subjects performing flight simulation operations.Design/methodology/approachFirst, a flight simulator that met the needs of the research project was designed and fabricated. Second, the tracking system was tested and deemed operable through a series of shakedown runs. Then, the head motion of test subjects was detected and measured using infrared technology. Finally, the data collected were used to establish definitions for head‐tilt and pilot fatigue.FindingsHead‐tilt and pilot fatigue were defined and evidence of their presence was observed in the head motion data.Practical implicationsThe goal of this research is to reduce aircraft accidents upon landing and take‐off for general, commercial, and military aviation to include unmanned aerial vehicles.Originality/valueLiterature which covers the definition and measurement of a pilot's head motion in flight is unclear. By defining the optokinetic phenomena of head‐tilt and precisely measuring pilot head motion and developing and using tests of pilots based on the results to screen for head‐tilt, the number of land aircraft veering off runways during both landing and takeoff can be reduced. Also, the number of aircraft overshooting the flight deck on an aircraft carrier can be reduced, as well as fewer crashes upon landing of unmanned aerial vehicles.

Method of pose estimation for UAV landing

In order to achieve the goal of the autonomous landing of fixed-wing unmanned aerial vehicles (UAVs), a new method is put forward for using the monocular camera on board to provide the information, which is need for landing. It is not necessary to install additional equipment in the airport. The vision-based method only makes use of the two edge lines on both sides of the main runway and the front edge line of the airport without using the horizon. While the runway width is known, the method can produce the attitude and position parameters of landing. The results of the hardware-in-the-loop simulation show the proposed method has better accuracy and faster computation speed. OCIS codes: 040.1490, 080.1235, 080.2720, 200.4560. doi: 10.3788/COL201210.S20401. In recent years, the study on autonomous landing of unmanned aerial vehicle (UAV) has being a research focus, especially based on vision. This approach has two attractive features. Firstly, video cameras/sensors are passive sensors; hence, they cannot be detected and artificially interfered with easily. Secondly, most UAVs are already equipped with video cameras (e.g., for ground reconnaissance); hence, vision-based navigation does not require much additional hardware or payload. Research on the key technology of vision-based navigation is the measurement of landing attitude and position of UAV using the runway images taken by the camera on UAV.

Non-linear position control for hover and automatic landing of unmanned aerial vehicles

This study presents a disturbance attenuation controller for horizontal position stabilisation for hover and automatic landings of a rotary-wing unmanned aerial vehicle (RUAV) operating close to the landing deck in rough seas. Based on a helicopter model representing aerodynamics during the landing phase, a non-linear state feedback ℋ∞ controller is designed to achieve rapid horizontal position tracking in a gusty environment. Practical constraints including flapping dynamics, servo dynamics and time lag effect are considered. A high-fidelity closed-loop simulation using parameters of the Vario XLC gas-turbine helicopter verifies performance of the proposed horizontal position controller. The proposed controller not only increases the disturbance attenuation capability of the RUAV, but also enables rapid position response when gusts occur. Comparative studies show that the ℋ∞ controller exhibits performance improvement and can be applied to ship/RUAV landing systems.

Design and Attitude Control of a Quad-Rotor Tail-Sitter Vertical Takeoff and Landing Unmanned Aerial Vehicle

In this paper, we present the development of a quad-rotor tail-sitter unmanned aerial vehicle (UAV) that is composed of quad rotors and a fixed wing. The developed UAV can hover like a quad-rotor helicopter and can fly long distance like a fixed-wing airplane. The main wing of the developed UAV is taken from a commercially available radio-controlled airplane and other parts such as the body frame are newly developed. A microcomputer, various sensors and a battery are mounted on the UAV for autonomous flight without any support from a ground system. Attitude and altitude control systems are developed for the UAV. In order to verify the designed controller, a three-dimensional flight simulator of a quad-rotor tail-sitter UAV is developed by use of MATLAB/Simulink. This paper also describes attitude control experiments. The results show that the propeller slipstream has a negative influence on attitude control. Solutions for the negative influence of the propeller slipstream are also discussed in this paper.

Vision Based Autonomous Landing of an Unmanned Aerial Vehicle

The overall aim of present work is to develop a considerable robust and simple method for the estimation of the relative position of an unmanned aerial vehicle (UAV) with respect to a runway and automatic landing of UAV based on camera images. Various automatic landing systems based on INS, GPS, ILS and tracking radar are not always available or applicable due to complexity, cost or limits from operating environment. Vision based landing has been found as an attractive since it is passive, low cost and does not require any special equipment other than a camera and a vision processing unit onboard. An uncalibrated camera is used to give high accuracy position information for automatic landing on the runway. In addition to camera, only an airspeed sensor is added because the velocity relative to the air is very important during landing. The special feature of this method is that neither a calibrated camera (referring to focus length and mounting angles relative to the aircraft) is required nor the identification of special points of the runway and their 3-D location has to be known. The only reference to the 3-D world which has to be known is the width of the runway stripe. The robustness and the minimum requirement of real-world 3-D data yield a lower effort for certification, calibration and maintenance of a camera based positioning system. The proposed algorithm extracts the runway boundary lines using Hough transform and estimates the position, lateral offset of UAV with respect to the runway centre line. An aircraft model for simulation and control system design purposes is also presented. Finally, some simulation results using Flight Gear simulation software, where the described method has been implemented, are explained.

A fully autonomous unmanned aerial vehicle landing controller synthesis: quantitative feedback theory and H∞ technique comparison

This article presents an overview of the design of an autonomous landing controller. The flight control system must be robust against the effects of wind and must control the height accurately enough to support an autoland function. This study design and compare two different altitude command tracker controllers for an unmanned air vehicle using H∞ and quantitative feedback theory (QFT) techniques during the landing phase. The different stages of QFT methodology have been done with help of software tool quantitative feedback theory interactive tool. This is a free software tool that is characterized by its easy of use and interactive nature. QFT is standing as a viable control design method that can be applied to practical problems and produce implementable results. Tests with realistically large control inputs are used to validate and compare both designs.

Flight validation of a feedforward gust-attenuation controller for an autonomous helicopter

This paper presents a practical scheme to control heave motion for hover and automatic landing of a Rotary-wing Unmanned Aerial Vehicle (RUAV) in the presence of strong horizontal gusts. A heave motion model is constructed for the purpose of capturing dynamic variations of thrust due to horizontal gusts. Through the construction of an effective gust estimator, a feedback–feedforward controller is developed which uses available measurements from onboard sensors. The proposed controller dynamically and synchronously compensates for aerodynamic variations of heave motion, enhancing disturbance-attenuation capability of the RUAV. Simulation results justify the reliability and efficiency of the suggested gust estimator. Moreover, flight tests conducted on our Eagle helicopter verify suitability of the proposed control strategy for small RUAVs operating in a gusty environment.

A hierarchical controller for miniature VTOL UAVs: Design and stability analysis using singular perturbation theory

This paper presents the design and the stability analysis of a hierarchical controller for unmanned aerial vehicles (UAV), using singular perturbation theory. Position and attitude control laws are successively designed by considering a time-scale separation between the translational dynamics and the orientation dynamics of a six degrees of freedom vertical take-off and landing (VTOL) UAV model. For the design of the position controller, we consider the case where the linear velocity of the vehicle is not measured. A partial state feedback control law is proposed, based on the introduction of a virtual state into the translational dynamics of the system. Results from simulation and from experiments on a miniature quadrirotor UAV are provided to illustrate the performance of the proposed control scheme.

Evaluation of Eye Metrics as a Detector of Fatigue

This study evaluated oculometrics as a detector of fatigue in Air Force-relevant tasks after sleep deprivation. Using the metrics of total eye closure duration (PERCLOS) and approximate entropy (ApEn), the relation between these eye metrics and fatigue-induced performance decrements was investigated. One damaging effect to the successful outcome of operational military missions is that attributed to sleep deprivation-induced fatigue. Consequently, there is interest in the development of reliable monitoring devices that can assess when an operator is overly fatigued. Ten civilian participants volunteered to serve in this study. Each was trained on three performance tasks: target identification, unmanned aerial vehicle landing, and the psychomotor vigilance task (PVT). Experimental testing began after 14 hr awake and continued every 2 hr until 28 hr of sleep deprivation was reached. Performance on the PVT and target identification tasks declined significantly as the level of sleep deprivation increased.These performance declines were paralleled more closely by changes in the ApEn compared to the PERCLOS measure. The results provide evidence that the ApEn eye metric can be used to detect fatigue in relevant military aviation tasks. Military and commercial operators could benefit from an alertness monitoring device.

UAV landing system simulation model software system

A software system for a simulation model of a UAV's automatic landing system is presented herein. The simulation model allows us to determine the level of influence of different distortions of the observed image on the UAV's landing accuracy. The correlation extremal system of terminal guidance (CESTG) of an unmanned aerial vehicle (UAV) executed on the basis of an optoelectronic sensor has found its application as a tool providing the terminal delivery of UAV's freight to the planned Earth surface area or automatic landing of an unmanned helicopter (UH) on a selected place or on a surface ship deck. In operation, the CESTG carries out a search for a landing place (freight delivery), guidance to the selected landing place (freight delivery) at the UAV's approach and the exact path of the UAV to the selected area in the processing of current information receiving at the discrete moments of time (shot shaping time) about the surveillance area from the optoelectronic sensor.

Parallel Tracking and Mapping for Controlling VTOL Airframe

This work presents a vision based system for navigation on a vertical takeoff and landing unmanned aerial vehicle (UAV). This is a monocular vision based, simultaneous localization and mapping (SLAM) system, which measures the position and orientation of the camera and builds a map of the environment using a video stream from a single camera. This is different from past SLAM solutions on UAV which use sensors that measure depth, like LIDAR, stereoscopic cameras or depth cameras. Solution presented in this paper extends and significantly modifies a recent open‐source algorithm that solves SLAM problem using approach fundamentally different from a traditional approach. Proposed modifications provide the position measurements necessary for the navigation solution on a UAV. The main contributions of this work include: (1) extension of the map building algorithm to enable it to be used realistically while controlling a UAV and simultaneously building the map; (2) improved performance of the SLAM algorithm for lower camera frame rates; and (3) the first known demonstration of a monocular SLAM algorithm successfully controlling a UAV while simultaneously building the map. This work demonstrates that a fully autonomous UAV that uses monocular vision for navigation is feasible.

Modelling of Opposed Lateral and Longitudinal Tilting Dual-Fan Unmanned Aerial Vehicle

AbstractIn this paper, first an overview and explanation of the Oblique Active Tilting (OAT) and Opposed Lateral Tilting (OLT) control concepts are presented. A complete dynamic model of vertical take-off and landing (VTOL) unmanned aerial vehicles (UAVs) having lateral and longitudinal rotor tilting mechanism is developed using a Newton-Euler formulation for double axis OAT mechanism (dOAT). Then, a theoretical analysis of OAT vehicle control response and stability for pitch, roll and yaw motion is described and simulated using the derived dynamic model. The aim of the aspects presented in this paper is to fully enable the highly maneuverable characteristics of UAV possessing dOAT which renders them to navigate in highly confined environments by performing semi-acrobatic maneuvers in hover lateral and forward flight.