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1
Tsitses, Ioannis, Paraskevi Zacharia, Elias Xidias und Michail Papoutsidakis. „A Fuzzy-Based System for Autonomous Unmanned Aerial Vehicle Ship Deck Landing“. Sensors 24, Nr. 2 (21.01.2024): 680. http://dx.doi.org/10.3390/s24020680.
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This paper introduces a fuzzy logic-based autonomous ship deck landing system for fixed-wing unmanned aerial vehicles (UAVs). The ship is assumed to maintain a constant course and speed. The aim of this fuzzy logic landing model is to simplify the task of landing UAVs on moving ships in challenging maritime conditions, relieving operators from this demanding task. The designed UAV ship deck landing model is based on a fuzzy logic system (FLS), which comprises three interconnected subsystems (speed, lateral motion, and altitude components). Each subsystem consists of three inputs and one output incorporating various fuzzy rules to account for external factors during ship deck landings. Specifically, the FLS receives five inputs: the range from the deck, the relative wind direction and speed, the airspeed, and the UAV’s flight altitude. The FLS outputs provide data on the speed of the UAV relative to the ship’s velocity, the bank angle (BA), and the angle of descent (AOD) of the UAV. The performance of the designed intelligent ship deck landing system was evaluated using the standard configuration of MATLAB Fuzzy Toolbox.
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Cheng, Chen, Zian Wang, Zheng Gong, Pengcheng Cai und Chengxi Zhang. „Prediction and Compensation Model of Longitudinal and Lateral Deck Motion for Automatic Landing Guidance System“. Mathematics 10, Nr. 19 (21.09.2022): 3440. http://dx.doi.org/10.3390/math10193440.
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This paper mainly studies the longitudinal and lateral deck motion compensation technology. In order to ensure the safe landing of the carrier-based aircrafts on the flight decks of carriers during the landing process, it is necessary to introduce deck motion information into the guidance law information of the automatic landing guidance system when the aircraft is about to land so that the aircraft can track the deck motion. To compensate the influence of the height change in the ideal landing point on the landing process, the compensation effects of the deck motion compensators with different design parameters are verified by simulation. For further phase-lead compensation for the longitudinal automatic landing guidance system, a deck motion predictor is designed based on the particle filter optimal prediction theory and the AR model time series analysis method. Because the influence of up and down motions on the vertical motion of the ideal landing point is the largest, the compensation effects of the designed predictor and compensator are simulated and verified based on the up and down motion of the power spectrum. For the compensation for the lateral motion, a tracking strategy of the horizontal measurement axis of the inertial stability coordinate system to the horizontal axis of the hull coordinate system (center line of the deck) is proposed. The tracking effects of the horizontal measurement axis of the designed integral and inertial tracking strategies are simulated and compared. Secondly, the lateral deck motion compensation commands are designed, and the compensation effects of different forms of compensation commands are verified by simulations. Finally, the compensation effects for the lateral deck motion under integral and inertial tracking strategies are simulated and analyzed.
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Wang, Zhen Qing, Xiao Yu Sun, Song Zhou und Hong Shuai Lei. „Dynamics Analysis of Aircraft Landing on the Pitching Deck“. Key Engineering Materials 467-469 (Februar 2011): 579–82. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.579.
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In order to study the aircraft landing on the deck, the landing(on or off center) dynamics model of airplane on deck is built.In this model,the interactions of the aircraft landing attitude , the arresting force acting on the aircraft are considered,and the influence of dynamic deck is introduced into the model .The deck coordinate system is put forward to solve the complex simulation problem..At last,by simulation,it is demonstrated that the model can be applied to the aircraft landing attitude,it is also proved that the model is comprehensive and suitable for any abnormal landing situation.
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Yin, Hai Tao, Xin Min Wang, Wen Chao Li und Rong Xie. „Study of Disturbances Model on Carrier-Based Aircraft Landing Process“. Applied Mechanics and Materials 321-324 (Juni 2013): 824–28. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.824.
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The disturbances in the landing process of carrier-based aircraft include deck movement and ship wake. To guarantee the security of landing process, the simulation and model are necessary for the disturbances, and the deck movement and ship wake should be analyzed as well. On the basis of analysis of disturbances, the disturbances can be catalogued into two types: deck movement and ship wake. Combining with the relevant instructions in the American Army Standard, the mathematical model of each disturbance is established. The simulations of the deck movement and ship wake are also shown in this paper, which can supply the reliable disturbances models for the design of the control system of carrier-aircraft landing process.
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O'Reilly, Peter J. F. „Aircraft/Deck Interface Dynamics for Destroyers“. Marine Technology and SNAME News 24, Nr. 01 (01.01.1987): 15–25. http://dx.doi.org/10.5957/mt1.1987.24.1.15.
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The interface between vertical takeoff and landing (VTOL) aircraft and destroyer and frigate-type warships involves a great many factors. This paper discusses a computer analytical technique which permits dynamic analysis of the aircraft landing or taking off from a moving deck or being handled or stowed on the ship. A condensed explanation of how the synthetic time histories are generated is contained in the Appendix. Two examples of how the technique has been used are included: first, a Recovery Assist and Secure System (RAS) analysis, and second, a pilot landing aid system, the Landing Period Designator (LPD) research program.
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Yang, Wenqi, Siyu Zhou, Jianhua Lu und Liting Song. „Longitudinal Control Technology for Automatic Carrier Landing Based on Model-compensated Active Disturbance Rejection Control“. Journal of Physics: Conference Series 2477, Nr. 1 (01.04.2023): 012095. http://dx.doi.org/10.1088/1742-6596/2477/1/012095.
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Abstract Carrier aircraft landing is a system engineering with strong nonlinear, strong coupling, and complex environmental interference. Landing control is one of the key technologies for carrier aircraft landing, which directly affects the success of the landing. A longitudinal decoupling control method based on Model Compensated Linear Active Disturbance Rejection Control (MCC-LADRC) is proposed for tracking the deck motion and maintaining the attack angle in the final stage of the carrier landing. The simulation results show that compared with the PID control and traditional LADRC strategy, the MCC-LADRC method can not only control the carrier aircraft to track the deck motion synchronously and accurately, improve the landing accuracy and anti-disturbance capability but also has a good attack angle retention effect and eliminate the coupling between the pitch angle and the attack angle.
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Li, Xu, Xiaoping Zhu, Zhou Zhou und Xiaoping Xu. „The Numerical Simulation of UAV's Landing in Ship Airwake“. Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 37, Nr. 1 (Februar 2019): 186–94. http://dx.doi.org/10.1051/jnwpu/20193710186.
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In order to investigate the influence of ship airwake on aerodynamic characteristics of the carrier-based aircraft, UAV's landings in different winds over deck were simulated by Overset Mesh method. Firstly, mesh factors, steady and unsteady methods were compared based on single aircraft carrier. The results showed that the boundary layer mesh around ship didn't show obvious influence for our simulation, and the calculation results between the steady and unsteady time average showed a similar trend. Then, aircraft carrier's flow fields in three wind directions were analyzed, and ship airwake variations with different direction winds over deck were concluded as well. Next, the reliability of Overset Mesh was verified though single UAV's landing simulation. Finally, the coupled flow fields of UAV/ship were studied. The calculation results indicated that aircraft was always in a low dynamic pressure condition, the lift and pitching moment of UAV had apparent changes in landing. Meanwhile, the aerodynamic fluctuations of UAV also revealed differences in different wind directions. The simulation results can be regarded as a reference for the safety assessment of carrier-based aircraft's landing and its control in the future.
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Bhatia, Ajeet Kumar, Jiang Ju, Zhen Ziyang, Nigar Ahmed, Avinash Rohra und Muhammad Waqar. „Robust adaptive preview control design for autonomous carrier landing of F/A-18 aircraft“. Aircraft Engineering and Aerospace Technology 93, Nr. 4 (03.06.2021): 642–50. http://dx.doi.org/10.1108/aeat-11-2020-0244.
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Purpose The purpose of this paper is to design an innovative autonomous carrier landing system (ACLS) using novel robust adaptive preview control (RAPC) method, which can assure safe and successful autonomous carrier landing under the influence of airwake disturbance and irregular deck motion. To design a deck motion predictor based on an unscented Kalman filter (UKF), which predicts the touchdown point, very precisely. Design/methodology/approach An ACLS is comprising a UKF based deck motion predictor, a previewable glide path module and a control system. The previewable information is augmented with the system and then latitude and longitudinal controllers are designed based on the preview control scheme, in which the robust adaptive feedback and feedforward gain’s laws are obtained through Lyapunov stability theorem and linear matrix inequality approach, guarantying the closed-loop system’s asymptotic stability. Findings The autonomous carrier landing problem is solved by proposing robust ACLS, which is validated through numerical simulation in presence of sea disturbance and time-varying external disturbances. Practical implications The ACLS is designed considering the practical aspects of the application, presenting superior performance with extended robustness. Originality/value The novel RAPC, relative motion-based guidance system and deck motion compensation mechanism are developed and presented, never been implemented for autonomous carrier landing operations.
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Li, Xiang, Sheng Huang und Chong Wang. „Analysis and Research on Flight Mechanics with Air-Wake around Large Warship Decks“. Advanced Materials Research 977 (Juni 2014): 395–98. http://dx.doi.org/10.4028/www.scientific.net/amr.977.395.
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For large warships, aircrafts play an important role in the war. So during the development of large warships, the safety of the aircrafts takeoff and landing becomes the key technology, which requires the air-wake around large warship decks provide a safety environment for its busy work. However, for the warships with flush deck, superstructure is the main reason of causing air turbulence on the ship surface. At the same time, the states of motion also have an effect on air-wake such as pitch, rolling, etc. It will lead to air crash or inability of takeoff and landing if the air-wake around decks cannot meet the work requirements of the aircrafts. Therefore, the numerical simulation of air-wake around decks is very important for the development of large warships during the war.
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Xue, Xiao-Feng, Yuan-Zhuo Wang, Cheng Lu und Zhang Yun-Peng. „Sinking Velocity Impact-Analysis for the Carrier-Based Aircraft Using the Response Surface Method-Based Improved Kriging Algorithm“. Advances in Materials Science and Engineering 2020 (07.05.2020): 1–13. http://dx.doi.org/10.1155/2020/5649492.
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The deck landing sinking velocity of carrier-based aircraft is affected by carrier attitude, sea condition, aircraft performance, etc. Its impact analysis is a complex nonlinear problem, and there even is some contradictory phenomenon that when the approach velocity increases, the sinking velocity decreases under certain circumstances. Aiming at exploring the impact of the various related deck landing parameters on sinking velocity for carrier-based aircraft in the actual environment, response surface method-based improved Kriging algorithm (IK-RSM) is proposed based on genetic algorithm and Kriging model. Based on the deck landing measured data of the F/A-18A aircraft in the actual operating environment, the impact degree of the 15 deck landing parameters on the sinking velocity is explored, respectively, by using the partial correlation analysis of multivariate statistical theory and the IK-RSM. It can be found that the 4 parameters are strongly correlated with the sinking velocity; that is, the aircraft glide angle and deck pitch angle are highly correlated with the sinking velocity; next, the approach velocity and the engaging velocity are moderately correlated with the sinking velocity. The 4 parameters above could be used to establish the impact analysis model of the sinking velocity. The genetic algorithm is applied to the correction coefficients optimization of the IK-RSM’s kernel functions, and the IK-RSM of the F/A-18A aircraft sinking velocity is formed. Compared with the Kriging model and the empirical formula, the sinking velocity prediction accuracy indexes of IK-RSM are the best; for example, the determination coefficient is 0.981, the mean relative error is 1.813%, and the maximum relative error is 6.771%. Furthermore, based on the sinking velocity IK-RSM and the sensitivity analysis method proposed, we have explained the reason for the contradictory phenomenon that when the approach velocity increases, the sinking velocity decreases at some samples. It could provide certain technical support for the flight attitude control related to the sinking velocity during the actual flight of carrier-based aircraft.
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Wang, Zeng, Xiancheng Wang und Ruidong Li. „Treadmill Deck Performance Optimization Design Based on Muscle Activity during Running“. Applied Sciences 13, Nr. 18 (19.09.2023): 10457. http://dx.doi.org/10.3390/app131810457.
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In previous research on treadmills, the main focus has been on comparing the physiological differences induced by running on treadmill decks and other exercise surfaces, with relatively little research on the mechanical properties of treadmill decks. Reducing sports injuries is a common desire of runners, which may be closely related to muscle activity. Obviously, the mechanical properties of the treadmill play an important role in this process. Muscle activity was evaluated based on a mass-spring-damper (MSD) model that provides a simulated signal of the ground reaction forces (GRF) and vibration of the lower-limb soft tissues (LLST) during the landing of the human body during running. We improved the original human motion model by considering the stiffness and damping effect of the treadmill deck. In addition, based on the theory of muscle activity regulation, the dimensionless objective function is established, and the particle swarm optimization algorithm is used to find the best range of treadmill deck parameters under pre- and post-fatigue conditions. The results show that the hardness of the treadmill deck can affect the regulation of muscle activity. Based on this, the parameters of the specific safe area of the treadmill deck are obtained, and the size of the safe area after fatigue is significantly reduced compared to that before fatigue. By studying the physiological effects of the mechanical properties of the treadmill deck on runners, the research results are expected to provide references for the design of treadmill deck parameters and reduce the risk of runners’ sports injuries, which has practical application value for treadmill design and runners’ health.
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Zhu, Qi Dan, Xue Meng und Zhi Zhang. „Simulation Research on Motion Law of Arresting Hook during Landing“. Applied Mechanics and Materials 300-301 (Februar 2013): 997–1002. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.997.
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The key of a safety landing is the arresting hook can engage an arresting wire. Thus, research on motion law of arresting hook during landing is essential. The construction features and function of typical arresting hook installation is studied. Take into consideration the influence on collision process produced by the deck friction in order to build an actual model of arresting hook during landing. So we can use the model to study the motion law of arresting hook during landing for the sake of supplying a beneficial reference to design of arresting hook and successful engagement with an arresting wire. Simulation results show that the value of height of first hook bounce diminishes linearly with increasing values of coefficient of friction and increases linearly with increasing values of sinking speed. Therefore, we should consider the deck friction in an arresting hook collision which is available for designing a reasonable damper and must ensure the value of sinking speed in a reasonable range to satisfy the condition of engagement with arresting gear.
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Lungu, Mihai, Mou Chen und Dana-Aurelia Vîlcică (Dinu). „Backstepping- and Sliding Mode-Based Automatic Carrier Landing System with Deck Motion Estimation and Compensation“. Aerospace 9, Nr. 11 (24.10.2022): 644. http://dx.doi.org/10.3390/aerospace9110644.
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This paper addresses the automatic carrier landing problem in the presence of deck motion, carrier airwake disturbance, wind shears, wind gusts, and atmospheric turbulences. By transforming the 6-DOF aircraft model into an affine dynamic with angle of attack controlled by thrust, the equations associated to the resultant disturbances are deduced; then, a deck motion prediction block (based on a recursive-least squares algorithm) and a tracking differentiator-based deck motion compensation block are designed. After obtaining the aircraft reference trajectory, the backstepping control method is employed to design a novel automatic carrier landing system with three functional parts: a guidance control system, an attitude control system, and an approach power compensation system. The design of the attitude subsystem involves the flight path control, the control of the attitude angles, and the control of the angular rates. To obtain convergence performance for the closed-loop system, the backstepping technique is combined with sliding mode-based command differentiators for the computation of the virtual commands and extended state observers for the estimation of the disturbances. The global stability of the closed-loop architecture is analyzed by using the Lyapunov theory. Finally, simulation results verify the effectiveness of the proposed carrier landing system, the aircraft reference trajectory being accurately tracked.
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Liu, Bingjie. „Numerical Study of Flow Field Over the Deck with Active Flow Control Method“. Highlights in Science, Engineering and Technology 15 (26.11.2022): 199–206. http://dx.doi.org/10.54097/hset.v15i.2223.
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When the destroyer is sailing on the sea, the turbulent ship airwake will be formed above the deck, due to the flow separation after the airflow passes through the edge of the hangar, and the most obvious vortex structure is the recirculation area, which will seriously affect the safety of take-off and landing of the ship-borne helicopter on the deck. Based on the means of flow control in fluid dynamics, this paper improves the quality of the flow field above the deck of the destroyer by adopting different blowing ways (3 blowing angles and 5 blowing speeds). The results show that for different blowing directions, the length of recirculation zone tends to decrease with the increase of blowing speed. The optimal blowing way is the blowing speed of 10m/s in the blowing direction of -45°, and the length of recirculation zone is reduced by 59.4%. This will obviously improve the landing safety of ship-borne helicopters and reduce the pilot's control load.
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Mascia, Donatella. „Structural behaviour of landing deck marine vessel under dynamic actions of aircraft landing“. Ships and Offshore Structures 5, Nr. 3 (02.09.2010): 267–82. http://dx.doi.org/10.1080/17445300903566173.
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Hu, Hanjie, Yu Wu, Jinfa Xu und Qingyun Sun. „Path Planning for Autonomous Landing of Helicopter on the Aircraft Carrier“. Mathematics 6, Nr. 10 (27.09.2018): 178. http://dx.doi.org/10.3390/math6100178.
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Helicopters are introduced on the aircraft carrier to perform the tasks which are beyond the capability of fixed-wing aircraft. Unlike fixed-wing aircraft, the landing path of helicopters is not regulated and can be determined autonomously, and the path planning problem for autonomous landing of helicopters on the carrier is studied in this paper. To solve the problem, the returning flight is divided into two phases, that is, approaching the carrier and landing on the flight deck. The feature of each phase is depicted, and the conceptual model is built on this basis to provide a general frame and idea of solving the problem. In the established mathematical model, the path planning problem is formulated into an optimization problem, and the constraints are classified by the characteristics of the helicopter and the task requirements. The goal is to reduce the terminal position error and the impact between the helicopter and the flight deck. To obtain a reasonable landing path, a multiphase path planning algorithm with the pigeon inspired optimization (MPPIO) algorithm is proposed to adapt to the changing environment. Three experiments under different situations, that is, static carrier, only horizontal motion of carrier considered, and 3D motion of carrier considered, are conducted. The results demonstrate that the helicopters can all reach the ideal landing point with the reasonable path in different situations. The small terminal error and relatively vertical motion between the helicopter and the carrier ensure a precise and safe landing.
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Thomson, D. G., F. Coton und R. Galbraith. „A Simulation Study of Helicopter Ship Landing Procedures Incorporating Measured Flow-Field Data“. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 219, Nr. 5 (01.05.2005): 411–27. http://dx.doi.org/10.1243/095441005x30351.
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The aim of this article is to investigate the use of inverse simulation to help identify those regions of a ship's flight deck which provide the safest locations for landing a rotorcraft in various atmospheric conditions. This requires appropriate information on the wind loading conditions around a ship deck and superstructure, and for the current work, these data were obtained from wind tunnel tests of a ship model representative of a typical helicopter carrier/assault ship. A series of wind tunnel tests were carried out on the model in the University of Glasgow's 2.65 × 2.04 m wind tunnel and three-axis measurements of wind speed were made at various locations on the ship deck. Measurements were made at four locations on the flight deck at three different heights. The choice of these locations was made on the basis of preliminary flow visualization tests which highlighted the areas where the most severe wind effects were most likely to occur. In addition, for the case where the wind was from 30° to starboard, measurements were made at three further locations to assess the extent of the wake of the superstructure. The generated wind profiles can then be imposed on the inverse simulation, allowing study of the vehicle and pilot response during a typical landing manoeuvre in these conditions. The power of the inverse simulation for this application is demonstrated by a series of simulations performed using configurational data representing two aircraft types, a Westland Lynx and a transport helicopter flying an approach and landing manoeuvre with the worst atmospheric conditions applied. It is shown from the results that attempting to land in the area aft of the superstructure in a 30° crosswind might lead to problems for the transport configuration due to upgusts in this area. Attempting to perform the landing manoeuvre in an aggressive manner is also shown to lead to diminished control margin in higher winds.
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Wang, Fanchao, Kai Zheng, Bihao Chen, Yinghao Peng, Kun Liu und Dewen Tang. „Time-Domain Inversion Method of Impact Loads Based on Strain Monitoring Data“. Metals 12, Nr. 8 (29.07.2022): 1279. http://dx.doi.org/10.3390/met12081279.
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A helicopter deck is the main load-bearing component under the emergency landing conditions for helicopters. However, it is generally difficult to directly obtain the landing load from measurements due to the high randomness of the landing position. As the main design load of the helicopter deck, the emergency landing load is very important to its structural design. A large design load value leads to an overly conservative structural design and affects the control of the ship’s weight and center of gravity, while a small design load may lead to a lack of security and affect the safety of the helicopter and the ship. As a result, the time domain inversion method, which is based on strain monitoring data, is an important and effective method for obtaining the helicopter emergency landing load. In this study, a grillage model experiment was conducted to study the time domain inversion method. The helicopter impact load was simulated by falling body impact, and the impact load history and structural strain response were recorded by sensors. The grillage model impact load was calculated with different inversion methods, including the direct inverse, truncated singular value decomposition (TSVD), and Tikhonov regularization methods. The solution accuracy of different methods and number of sensors needed were compared. The results demonstrated that the Tikhonov regularization method based on four measurement points along with the L-curve determination criterion showed a better performance for capturing the impact load time history features.
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Makarenko, A. A. „Algorithm for determining the angular position of the ship’s deck from an unmanned aircraft using digital image processing“. Radio industry (Russia) 30, Nr. 4 (23.12.2020): 87–97. http://dx.doi.org/10.21778/2413-9599-2020-30-4-87-97.
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Problem statement. An unmanned vertical take-off and landing aircraft equipped with means for analyzing parameters of a certain pattern is usually not able to land on a landing site that is not equipped with the appropriate markings. To solve this problem, it is possible to install onboard the UMA means for generating a special test image that is projected from the aircraft to the intended landing site, and means for automatically measuring and analyzing the parameters of this image.Objective. Develop an algorithm for applying digital image processing to determine the angular position of the ship’s deck or any other flat landing ground from an unmanned aircraft with vertical take-off and landing. The article presents the calculated relations that allow calculating the angular position and evaluating the general condition of the landing ground using a 3D model of its surface.Results. An algorithm has been developed according to which a particular test image is generated by a group of laser emitters on the landing site. Digital image processing methods are used to analyze the test image to assess the condition and determine the inclination angles of the landing site.Practical implications. The test results of the considered algorithm showed the possibility of its application in the system of automatic landing of an unmanned aircraft with vertical take-off and landing.
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Wang, Liyang, und Xiaoli Bai. „Quadrotor Autonomous Approaching and Landing on a Vessel Deck“. Journal of Intelligent & Robotic Systems 92, Nr. 1 (26.12.2017): 125–43. http://dx.doi.org/10.1007/s10846-017-0757-5.
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Polvara, Riccardo, Sanjay Sharma, Jian Wan, Andrew Manning und Robert Sutton. „Autonomous Vehicular Landings on the Deck of an Unmanned Surface Vehicle using Deep Reinforcement Learning“. Robotica 37, Nr. 11 (08.04.2019): 1867–82. http://dx.doi.org/10.1017/s0263574719000316.
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SummaryAutonomous landing on the deck of a boat or an unmanned surface vehicle (USV) is the minimum requirement for increasing the autonomy of water monitoring missions. This paper introduces an end-to-end control technique based on deep reinforcement learning for landing an unmanned aerial vehicle on a visual marker located on the deck of a USV. The solution proposed consists of a hierarchy of Deep Q-Networks (DQNs) used as high-level navigation policies that address the two phases of the flight: the marker detection and the descending manoeuvre. Few technical improvements have been proposed to stabilize the learning process, such as the combination of vanilla and double DQNs, and a partitioned buffer replay. Simulated studies proved the robustness of the proposed algorithm against different perturbations acting on the marine vessel. The performances obtained are comparable with a state-of-the-art method based on template matching.
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Li, Xiang, Sheng Huang, Song Ding und Lang Gu. „Analysis of Air-Flow Field of Large Ships in Waves“. Applied Mechanics and Materials 494-495 (Februar 2014): 309–12. http://dx.doi.org/10.4028/www.scientific.net/amm.494-495.309.
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Movement of large ship in waves is one of the important factors which can induce ship surface air turbulence; it is bound to a large impact on the air-flow field on deck, which affect the safety of the aircraft landing. In order to study the change of the flow field in the process of movement of large ship and its influence on aircrafts take-off and landing, under the same experimental condition of the unsteady condition. We set up 3d model, observe and analyze the ships air-flow field changes in the movement. Finally, calculate the results and give the effect of the aircraft landing in the key areas.
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Jiang, Xing Wei, Qi Dan Zhu und Zi Xia Wen. „Receding Horizon Control on Automatic Landing Lateral Loop of Carrier-Based Aircraft“. Applied Mechanics and Materials 300-301 (Februar 2013): 1610–16. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.1610.
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Since the angled deck is only tens miles width, the task of landing an aircraft on an aircraft carrier requires precise control, especially lateral loop. For this problem, this paper focuses on researching the aircraft automatic landing lateral control. In lateral control, the most crucial parts are controlling the off center distance and keeping the desired landing attitude. So firstly a nonlinear kinetic model of aircraft landing in lateral directional axis is established, and then transformed into error states. The controller is designed for an angle of attack of 11.7 deg and an airspeed of 40m/s, the equilibrium point. Receding horizon control methodology is employed to solve the aircraft lateral control problem. This controller is solved in MATLAB, and sent to the 3D simulation environment by network communication, to control the aircraft landing lateral loop. The simulation environment is programmed based on VC++ software. The simulation results show that receding horizon control method can achieve trajectory tracking and attitude tracking of nonlinear aircraft landing system.
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Sun, Xiaoyun, Ju Jiang, Ziyang Zhen und Ruonan Wei. „Adaptive fuzzy direct lift control of aircraft carrier-based landing“. Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 39, Nr. 2 (April 2021): 359–66. http://dx.doi.org/10.1051/jnwpu/20213920359.
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Considering the precise landing demand for carrier-based aircraft flight control, this paper proposes an adaptive fuzzy landing control method for the strong time-varying, parameter uncertainty and various complex coupling in the actual state aircraft model. This method is applied to the flap channel to achieve direct lift control, and the fuzzy system is utilized to approximate the six-degree-of-freedom nonlinear system model of a carrier aircraft that is difficult to accurately describe, to achieve accurate tracking of the landing glideslope, and improve the landing accuracy. Lyapunov method was used to judge the stability of the adaptive fuzzy control algorithm. During the simulation, the airwake and deck motion disturbance were introduced to simulate the landing environment of the aircraft. The effectiveness of the landing control system was verified by the Matlab software. Monte-Carlo random test was utilized to carry out the landing point accuracy for the conventional control scheme and the adaptive fuzzy direct lift control scheme respectively. Through the response curve and landing point statistical results, it is confirmed that the direct lift control scheme has better control effect, and the landing precision has improvement compared with the conventional control scheme.
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Zhou, Jin, Jianjiang Zeng, Jichang Chen und Mingbo Tong. „Analysis of Global Sensitivity of Landing Variables on Landing Loads and Extreme Values of the Loads in Carrier-Based Aircrafts“. International Journal of Aerospace Engineering 2018 (2018): 1–14. http://dx.doi.org/10.1155/2018/2105682.
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When a carrier-based aircraft is in arrested landing on deck, the impact loads on landing gears and airframe are closely related to landing states. The distribution and extreme values of the landing loads obtained during life-cycle analysis provide an important basis for buffering parameter design and fatigue design. In this paper, the effect of the multivariate distribution was studied based on military standards and guides. By establishment of a virtual prototype, the extended Fourier amplitude sensitivity test (EFAST) method is applied on sensitivity analysis of landing variables. The results show that sinking speed and rolling angle are the main influencing factors on the landing gear’s course load and vertical load; sinking speed, rolling angle, and yawing angle are the main influencing factors on the landing gear’s lateral load; and sinking speed is the main influencing factor on the barycenter overload. The extreme values of loads show that the typical condition design in the structural strength analysis is safe. The maximum difference value of the vertical load of the main landing gear is 12.0%. This research may provide some reference for structure design of landing gears and compilation of load spectrum for carrier-based aircrafts.
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Li, Hai-Xu, Fei-Yun Gao, Chu-Jun Hu, Qiang-Lin An, Xiu-Quan Peng und Yan-Ming Gong. „Trajectory Track for the Landing of Carrier Aircraft with the Forecast on the Aircraft Carrier Deck Motion“. Mathematical Problems in Engineering 2021 (24.12.2021): 1–11. http://dx.doi.org/10.1155/2021/5597878.
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The paper presents a prediction method of deck lateral-directional motion for the control of landing trajectory of aircraft. Firstly, through the analysis of the process of aircraft returning to the ship, the modeling of the motion has been built. Secondly, in view of the delay of trajectory tracking captured in the actual process of aircraft landing on the ship, the error caused by the carrier motion signal has been analyzed. Based on the simulation results, the recommended prediction time of carrier motion has been proposed.
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Ren, Bo, Tianjiao Li und Xiang Li. „Research on Dynamic Inertial Estimation Technology for Deck Deformation of Large Ships“. Sensors 19, Nr. 19 (25.09.2019): 4167. http://dx.doi.org/10.3390/s19194167.
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Many kinds of weapon systems and launching equipment on the deck of large ships are easily affected by deck deformation. In order to ensure the accuracy of weapon systems and the safety of taking off and landing of carrier aircraft, a dynamic estimation method combining the main inertial navigation systems (INS) and the sub-inertial navigation systems (SINS) is designed to estimate the curvature and torsion of any trajectory on the deck. Our contributions start from the fact that the area of concern extends from the fixed points to any trajectory on the deck. The dynamic filter algorithm of wavelet combined with Kalman filter is used to process the acquired data. The wavelet method is used to remove the outliers in the acquired data, and the Kalman filter effectively reduces the influence of white noise, so that the estimation accuracy is guaranteed. The simulation results clearly show that the deck deformation of large ships can be obtained accurately in real-time over the observed area which proved that this dynamic inertial measurement method is feasible in practical engineering application.
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Tušl, Martin, Giuseppe Rainieri, Federico Fraboni, Marco De Angelis, Marco Depolo, Luca Pietrantoni und Andrea Pingitore. „Helicopter Pilots’ Tasks, Subjective Workload, and the Role of External Visual Cues During Shipboard Landing“. Journal of Cognitive Engineering and Decision Making 14, Nr. 3 (26.08.2020): 242–57. http://dx.doi.org/10.1177/1555343420948720.
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Helicopter shipboard landing is a cognitively complex task that is challenging both for pilots and their crew. Effective communication, accurate reading of the flight instruments, as well as monitoring of the external environment are crucial for a successful landing. In particular, the final phases of landing are critical as they imply high workload situations in an unstable environment with restricted space. In the present qualitative study, we interviewed ten helicopter pilots from the Italian Navy using an applied cognitive task analysis approach. We aimed to obtain a detailed description of the landing procedure, and to identify relevant factors that affect pilots’ workload, performance, and safety. Based on the content analysis of the interviews, we have identified six distinct phases of approaching and landing on a ship deck and four categories of factors that may significantly affect pilots’ performance and safety of the landing procedure. Consistent with previous studies, our findings suggest that external visual cueing is vital for a successful landing, in particular during the last phases of landing. Therefore, based on the pilots’ statements, we provide suggestions for possible improvements of external visual cues that have the potential to reduce pilots’ workload and improve the overall safety of landing operations.
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Guo, Jiahao, Xiaoping Zhu, Zhou Zhou und Xiaoping Xu. „Numerical Simulation and Characteristic Analysis of Ship's Air Flow Field“. Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 36, Nr. 6 (Dezember 2018): 1037–44. http://dx.doi.org/10.1051/jnwpu/20183661037.
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The air flow field of ship was simulated by using computational fluid dynamics technology to analyze its prime characteristics with reasonable accuracy. The different results of Reynolds-Averaged Navier-Stokes (RANS) method and Detached Eddy Simulation (DES) were compared, and the calculation traits of these methods were discussed. The results show that the air flow field of ship is unsteady. The accuracy of RANS simulation is insufficient for capturing this unsteady phenomenon. However, DES can catch this with better accuracy and expresses a comparatively great conformity with experimental data. Then, the aircraft carrier's flow field was calculated by DES. The characteristics of vortexes and velocity fluctuation on the ideal landing track were discussed in different wind directions. Those simulations indicate that there are complicated vortexes produced by blunt edges of the island and deck in the flow field. Those vortexes interact and mainly exist in the rear of flight deck and its adjacent air wake. Moreover, they cause a conspicuous and periodical velocity fluctuation on the ideal landing track as time goes on.
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Zhen, Ziyang, Ju Jiang, Xinhua Wang und Kangwei Li. „Modeling, control design, and influence analysis of catapult-assisted take-off process for carrier-based aircrafts“. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, Nr. 13 (20.06.2017): 2527–40. http://dx.doi.org/10.1177/0954410017715278.
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This paper addresses the problems of modeling, control design, and influence analysis of the steam catapult-assisted take-off process of the carrier-based aircrafts. The mathematical models of the carrier-based aircraft, steam catapult, landing gears, and the environmental factors including deck motion and bow airflow have been established to express the aircraft dynamics in the take-off process. An engineering method based automatic flight control system has been designed, which is divided into the longitudinal channel and lateral channel. The influences of the preset control surface, ship deck motion, ship bow airflow, and automatic flight control system system are tested by a series of simulations. The simulation results show that the elevator angle preset is necessary in the stage of accelerated running on the ship deck and the deck motion is the most important factor for safe take-off, while the ship bow airflow is beneficial for climbing up of the aircraft. The automatic flight control system gives the guarantee of safety and performance in the take-off process of the carrier-based aircraft.
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Tan, Chun Kiat, Jianliang Wang, Yew Chai Paw und Fang Liao. „Autonomous ship deck landing of a quadrotor using invariant ellipsoid method“. IEEE Transactions on Aerospace and Electronic Systems 52, Nr. 2 (April 2016): 891–903. http://dx.doi.org/10.1109/taes.2015.140850.
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Cao, Yihua, Yihao Qin, Wenyuan Tan und Guozhi Li. „Numerical Simulation of Fully Coupled Flow-Field and Operational Limitation Envelopes of Helicopter-Ship Combinations“. Journal of Marine Science and Engineering 10, Nr. 10 (08.10.2022): 1455. http://dx.doi.org/10.3390/jmse10101455.
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Landing a helicopter to the ship flight deck is most demanding even for the most experienced pilots and modeling and simulation of the ship-helicopter dynamic interface is a substantially challenging technical problem. In this paper, a coupling numerical method was developed to simulate the fully coupled ship-helicopter flow-field under complete wind-over-deck conditions. The steady actuator disk model based on the momentum source approach and the resolved blade method based on the moving overset mesh method were employed to model the rotor. Two different ship-helicopter combinations were studied. The helicopter flight mechanics model was established and then the influences of coupled airwake on the helicopter were analyzed. Finally, based on the derived rejection criterion of safe landing and the developed numerical method, the flight envelopes for these two ship-helicopter combinations were predicted. The steady actuator disk model was found to be effective in the study of helicopter operations in the shipboard environment. The calculated flight envelopes indicate that an appropriate wind direction angle is beneficial to increasing the allowable maximum wind speed and the operating boundary is affected by the rotation direction of the main rotor.
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Voskuijl, M., G. D. Padfield, D. J. Walker, B. J. Manimala und A. W. Gubbels. „Simulation of automatic helicopter deck landings using nature inspired flight control“. Aeronautical Journal 114, Nr. 1151 (Januar 2010): 25–34. http://dx.doi.org/10.1017/s000192400000350x.
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Abstract Research studies have indicated that the optical flow parameter, time to close tau, is the basis of purposeful control in the animal world, and used by both fixed wing and helicopter pilots during manoeuvring. This parameter is defined as the instantaneous time to close a gap (spatial or force) at the current closing rate. A novel automatic flight control strategy has been developed that makes use of optical flow theory and in particular, the parameter tau. This strategy has been applied to two distinct problems; (1) the landing of a helicopter on a ship and (2) the lateral repositioning of a helicopter. The first is a challenging case because the landing of a helicopter on a ship is one of the most dangerous of all helicopter flight operations. Furthermore, helicopters are often subject to torque oscillations during rapid collective control, which increases pilot workload significantly when operating with low power margins and/or whilst performing tasks that require accurate heave control. The second case demonstrates the generality of the technique. Both automatic manoeuvres were simulated successfully within desired limits, with the novel control strategy creating a ‘natural’, smooth, tau motion.
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Sezer-Uzol, N., A. Sharma und L. N. Long. „Computational Fluid Dynamics Simulations of Ship Airwake“. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 219, Nr. 5 (01.05.2005): 369–92. http://dx.doi.org/10.1243/095441005x30306.
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Computational fluid dynamics (CFD) simulations of ship airwakes are discussed in this article. CFD is used to simulate the airwakes of landing helicopter assault (LHA) and landing platform dock-17 (LPD-17) classes of ships. The focus is on capturing the massively separated flow from sharp edges of blunt bodies, while ignoring the viscous effects. A parallel, finite-volume flow solver is used with unstructured grids on full-scale ship models for the CFD calculations. Both steady-state and time-accurate results are presented for a wind speed of 15.43 m/s (30 knot) and for six different wind-over-deck angles. The article also reviews other computational and experimental ship airwake research.
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Su, D. C., Y. J. Shi und G. H. Xu. „Numerical study of the rotational direction effect on aerodynamic loading characteristics of shipborne helicopter rotor“. Aeronautical Journal 123, Nr. 1263 (Mai 2019): 635–57. http://dx.doi.org/10.1017/aer.2019.20.
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ABSTRACTNumerical simulations of ship/rotor-coupled flowfield have been performed to investigate the rotational direction effects on a shipborne single-rotor helicopter in different deck landing trajectories (i.e., lateral and longitudinal translation) based on Reynolds-averaged Navier-Stokes (RANS) solver. Both the momentum source model and moving overset mesh model are employed to simulate the effect of the rotor on the ship airwake for different levels of fidelity requirement. The aerodynamic loading characteristics in terms of time-averaged and root-mean-square (RMS) thrust and pitch and roll moments are compared for two helicopter rotors with opposite rotation directions in a starboard 30 degrees wind condition. The time-averaged results show that the mean thrust of a counterclockwise rotor is greater than that of a clockwise rotor, particularly in the lateral translation phase. This suggests that a helicopter with a counterclockwise rotor could provide more collective control margin under this condition. Furthermore, a more significant reduction in pitch moment is experienced by the counterclockwise rotor during the two landing trajectories, and thus the effect of the aircraft being pulled towards the hangar tends to be more severe on the helicopter with the counterclockwise rotor. RMS loading results indicate that the unsteady loading levels on the clockwise rotor are much higher than that of the counterclockwise rotor in all three axes for most of the lateral and longitudinal translation phases. As a result, the pilot is likely to experience a higher workload when operating a helicopter with a clockwise rotor in the case of a deck landing in this wind condition.
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Jang, Ho-Sang, Se-Yun Hwang und Jang-Hyun Lee. „Numerical Prediction of Convective Heat Flux on the Flight Deck of Naval Vessel Subjected to a High-Speed Jet Flame from VTOL Aircraft“. Journal of Marine Science and Engineering 10, Nr. 2 (14.02.2022): 260. http://dx.doi.org/10.3390/jmse10020260.
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This study examines the heat flux and convective heat transfer generated when a vertical take-off and landing (VTOL) aircraft takes off and lands on the flight deck of a naval vessel. A procedure for analyzing the convective heat transfer imposed on the deck by the high-temperature and high-velocity impingement of a VTOL jet is described. For the analysis, the jet velocity and the deck arrival temperature were calculated by applying computational fluid dynamics (CFD), assuming that the heat flow is an impingement jet. The relationships between the diameter of the jet, the speed of impingement, and the exhaust temperature of VTOL are introduced to assess the inlet condition. Heat flow was analyzed using CFD techniques, and Reynolds-averaged Navier–Stokes (RANS) and k-ε models were applied to model the turbulent motion. A procedure for evaluating the convection coefficient and convective heat flux from the calculated local velocity and temperature is presented. Simultaneously, a method for compensating the convection coefficient considering the singular velocity at the stagnation point is proposed. Furthermore, the accuracy was verified by comparing the convective heat flux and deck temperature predicted using CFD with the existing experimental studies. Finally, by applying finite element analysis (FEA) based on the thermal-structural interaction, the magnitude of thermal deformation due to conductive temperature and heat flux was presented as a design application of the flight deck.
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Mytilineou, Chryssi, Bent Herrmann, Danai Mantopoulou-Palouka, Antonello Sala und Persefoni Megalofonou. „Modelling gear and fishers size selection for escapees, discards, and landings: a case study in Mediterranean trawl fisheries“. ICES Journal of Marine Science 75, Nr. 5 (19.04.2018): 1693–709. http://dx.doi.org/10.1093/icesjms/fsy047.
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Abstract Gear selectivity and discards are important issues related to fisheries management but separately modelled. This work examines for the first time the overall size-selection pattern on the total amount of individuals of a species entering the trawl codend. An innovative approach was used based on modelling the escapement through the codend in the sea and the subsequently selection process by the fisher on the deck of the fishing vessel resulting into the discards and landings. Three different trawl codends and three species were investigated in the case study conducted. A dual sequential model accounting for both gear size-selectivity and the subsequent fisher-size-selectivity was applied, under the hypothesis that a fish entering the codend can follow a multinomial distribution with three probabilities, the escape, the discard and the landing probability, respectively. The model described the escape probability through the gear and the landing probability by the fisher as S-shaped curves leading to a bell-shaped curve for the discard probability affected by both gear and fisher selection. The model described well the experimental data in all cases. Sampling scheme of three compartments proved adequate. The model provides at the same time selectivity and discards parameters useful in fisheries management.
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Wen, Zhang, Zhang Zhi, Zhu Qidan und Xu Shiyue. „Dynamics Model of Carrier-based Aircraft Landing Gears Landed on Dynamic Deck“. Chinese Journal of Aeronautics 22, Nr. 4 (August 2009): 371–79. http://dx.doi.org/10.1016/s1000-9361(08)60113-2.
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Yang, Xilin, Matthew Garratt und Hemanshu Pota. „Monotonous Trend Estimation of Deck Displacement for Automatic Landing of Rotorcraft UAVs“. Journal of Intelligent & Robotic Systems 61, Nr. 1-4 (16.10.2010): 267–85. http://dx.doi.org/10.1007/s10846-010-9474-z.
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Xue, Xiaofeng, Yuanzhuo Wang und Cheng Lu. „Sinking Velocity Compact-Analysis of Carrier-Based Aircraft Based on Improved Kriging Model“. Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 37, Nr. 2 (April 2019): 218–24. http://dx.doi.org/10.1051/jnwpu/20193720218.
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The sinking velocity of carrier-based aircraft is an important input for landing gear design, and has a great influence on the weight of the landing gear and airframe structure. Aiming at exploring the effect of the various related landing parameters on the sinking velocity for carrier-based aircraft at the actual service environment, and based on F/A-18A measured landing data, the correlation degree between 15 landing parameters and sinking velocity is analyzed by partial correlation analysis method in multivariate statistics. The results show that the aircraft instantaneous gliding angle and deck pitch angle are highly correlated with the sinking velocity, the approach velocity and the engaging velocity are moderately correlated with the sinking velocity. The above four parameters are used as the independent variables, an improved Kriging surrogate model for the sinking velocity of F/A-18A aircraft is established, and Genetic algorithm is used to optimize the undetermined coefficients of correlation functions. The complex correlation coefficient of the sinking velocity predicted by the proposed model is 0.981, the average relative error is 1.813% and the maximum relative error is 6.771%. And comparing the empirical formula with the ordinary Kriging model, the precision index is the best. The proposed model provides the best prediction results. The improved Kriging surrogate model and the results obtained in this paper can provide a basis for studying the sinking velocity and controlling landing attitude for similar models carrier-based aircraft.
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Hernando, JL, und R. Martínez-Val. „Carrier deck launching of adapted land-based airplanes“. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 234, Nr. 10 (22.11.2019): 1661–74. http://dx.doi.org/10.1177/0954410019890233.
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VTOL Harrier aircraft has been the basic combat airplane for many Navies, but it will soon be retired from service. Three main alternatives appear: to incorporate another, already existing or under development airplane; to design a completely new aircraft; or to modify an existing land-based airplane to achieve carrier suitability. The present paper is part of a study to assess the feasibility of the third option. In former papers, the authors have addressed, firstly, the compatibility criteria of land-based airplanes with aircraft carriers and, secondly, the details of the approach guidance and the recovery manoeuvre, which showed the need of major modifications in wing structure and landing gear. The research proposed here studies the airplane performance during the take-off manoeuvre from mid-size carriers, formed by a flat deck take-off run followed by a ski-jump and the subsequent flyaway.
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XU, CUI, MING LIU, BIN KONG und YUNJIAN GE. „STEREO VISION-BASED ESTIMATION OF POSE AND MOTION FOR AUTONOMOUS LANDING OF AN UNMANNED HELICOPTER“. International Journal of Information Acquisition 03, Nr. 03 (September 2006): 181–90. http://dx.doi.org/10.1142/s0219878906000940.
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In this paper, a real-time stereo vision based pose and motion estimation system is presented. It is used for landing an unmanned helicopter on a moving target such as a ship deck. The vision algorithm mainly consists of a feature extraction task and a pose and motion estimation task. By the specially designed pattern of the landing target, the feature extraction algorithm can simplify the step of feature points matching of stereo system. In the task of feature extraction, the step of accurate corner detection can get to the precision of sub-pixel, which helps improve the measurement precision in state estimation. We present results from semi-physical simulation which show that our vision algorithm is accurate and robust to allow our vision sensor to be placed in the control loop of unmanned helicopter management system.
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Morice, Antoine H. P., Thomas Rakotomamonjy, Julien R. Serres und Franck Ruffier. „Ecological design of augmentation improves helicopter ship landing maneuvers: An approach in augmented virtuality“. PLOS ONE 16, Nr. 8 (11.08.2021): e0255779. http://dx.doi.org/10.1371/journal.pone.0255779.
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Helicopter landing on a ship is a visually regulated "rendezvous" task during which pilots must use fine control to land a powerful rotorcraft on the deck of a moving ship tossed by the sea while minimizing the energy at impact. Although augmented reality assistance can be hypothesized to improve pilots’ performance and the safety of landing maneuvers by guiding action toward optimal behavior in complex and stressful situations, the question of the optimal information to be displayed to feed the pilots’ natural information-movement coupling remains to be investigated. Novice participants were instructed to land a simplified helicopter on a ship in a virtual reality simulator while minimizing energy at impact and landing duration. The wave amplitude and related ship heave were manipulated. We compared the benefits of two types of visual augmentation whose design was based on either solving cockpit-induced visual occlusion problems or strengthening the online regulation of the deceleration by keeping the current τ˙ variable around an ideal value of -0.5 to conduct smooth and efficient landing. Our results showed that the second augmentation, ecologically grounded, offers benefits at several levels of analysis. It decreases the landing duration, improves the control of the helicopter displacement, and sharpens the sensitivity to changes in τ˙. This underlines the importance for designers of augmented reality systems to collaborate with psychologists to identify the relevant perceptual-motor strategy that must be encouraged before designing an augmentation that will enhance it.
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Yang, Xilin. „Displacement motion prediction of a landing deck for recovery operations of rotary UAVs“. International Journal of Control, Automation and Systems 11, Nr. 1 (26.01.2013): 58–64. http://dx.doi.org/10.1007/s12555-011-0157-8.
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Kääriä, C. H., J. S. Forrest und I. Owen. „The virtual AirDyn: a simulation technique for evaluating the aerodynamic impact of ship superstructures on helicopter operations“. Aeronautical Journal 117, Nr. 1198 (Dezember 2013): 1233–48. http://dx.doi.org/10.1017/s0001924000008836.
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AbstractThis paper describes a simulation technique that has been developed to quantify the unsteady forces and moments that are imposed onto a maritime helicopter by a ship’s airwake during a deck landing. An unsteady CFD-generated airwake, created using a CAD model of the ship, is integrated with a flight dynamics model of a helicopter. By holding the helicopter at a fixed position in the airwake it is possible to quantify the unsteady forces and moments imposed on the aircraft. The technique is therefore a software-based airwake dynamometer, and has been called the virtual AirDyn. As well as determining the mean loads, from consideration of the unsteady loads in the closed-loop pilot response frequency range of 0·2-2Hz it is also possible to quantify the magnitude of the unsteady disturbance in each axis. The loads are also indicators of the control activity the pilot would have to exert to maintain aircraft position and attitude. By placing the virtual AirDyn at different positions around the landing deck in different wind conditions, it is able to quantify the effect of the airwake on the mean and unsteady loads. The quantified loads can be explained by examining the CFD-generated flow field, and the geometric features on the ship’s superstructure that gave rise to them can be identified. The virtual AirDyn is therefore a tool that can be used to evaluate and inform ship design for maritime helicopter operations.
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Yu, Peng, Zhiyuan Hu, Guohua Xu und Yongjie Shi. „Numerical Simulation of Tiltrotor Flow Field during Shipboard Take-Off and Landing Based on CFD-CSD Coupling“. Aerospace 9, Nr. 5 (12.05.2022): 261. http://dx.doi.org/10.3390/aerospace9050261.
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Due to the small tilt angle, a tiltrotor operates in non-axial flow conditions during shipboard take-off and landing. The non-uniformity of the blade’s air-load is high, resulting in structural deformation with high fluctuation frequency, affecting the rotor’s aerodynamic characteristics. A new computational fluid-dynamic computational structural dynamics (CFD-CSD) solver is proposed to analyze the effects of the blade’s elastic deformation on the aerodynamic characteristics. This method is suitable for the aeroelastic simulation of shipboard tiltrotor take-offs and landings. The CFD method uses the Reynolds-averaged Navier-Stokes (RANS) equations as the control equation, while the CSD solver is based on the Timoshenko beam model. The solvers are combined with a two-way loose coupling strategy to improve the solution efficiency. The reverse overset assembly technique (ROAT) is utilized to eliminate the effects of orphan mesh points after deformation. The simulation is conducted during take-off and landing at different heights and different tilt angles, using the XV-15 tiltrotor as an example. An analysis of the rotor’s air-load and the mutual interference of the vortex and wake indicates that when the tiltrotor takes off or lands with a small tilt angle, the wing shedding vortex causes the rotor’s wake to roll upward before it reaches the ship’s deck, producing strong thrust fluctuations. The elastic deformation of the blade reduces the fluctuations in the thrust amplitude. This phenomenon is more pronounced in areas of high fluctuations in the blade’s air-load.
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Stanton, N. A., D. Harris, P. M. Salmon, J. M. Demagalski, A. Marshall, M. S. Young, S. W. A. Dekker und T. Waldmann. „Predicting design induced pilot error using HET (human error template) – A new formal human error identification method for flight decks“. Aeronautical Journal 110, Nr. 1104 (Februar 2006): 107–15. http://dx.doi.org/10.1017/s0001924000001056.
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Abstract Human factors certification criteria are being developed for large civil aircraft with the objective of reducing the incidence of design-induced error on the flight deck. Many formal error identification techniques currently exist which have been developed in non-aviation contexts but none have been validated for use to this end. This paper describes a new human error identification technique (HET – human error template) designed specifically as a diagnostic tool for the identification of design-induced error on the flight deck. HET is benchmarked against three existing techniques (SHERPA – systematic human error reduction and prediction approach; human error HAZOP – hazard and operability study; and HEIST – human error In systems tool). HET outperforms all three existing techniques in a validation study comparing predicted errors to actual errors reported during an approach and landing task in a modern, highly automated commercial aircraft. It is concluded that HET should provide a useful tool as a adjunct to the proposed human factors certification process.
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Saydam, Ahmet Ziya, Serhan Gokcay und Mustafa Insel. „Evaluation of Aerodynamic Characteristics of Mega-Yacht Superstructures by CFD Simulations“. Journal of Ship Production and Design 36, Nr. 04 (13.11.2020): 259–70. http://dx.doi.org/10.5957/jspd.09190051.
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Air wake distribution around the superstructure of a mega-yacht is a key concern for the designer because of various reasons such as comfort expectations in recreational deck areas, self-noise generation, air pollution and temperature gradients due to exhaust interactions, and safety of helicopter operations such as landing/take off and hovering. The Reynolds-averaged Navier-Stokes (RANS) technique in computational fluid dynamics (CFD) is frequently used in studies on mega-yacht hydrodynamics and aerodynamics with satisfactory results. In this article, a case study is presented for the utilization of CFD in a mega-yacht's superstructure design. The flow field in recreational open areas has been analyzed for the increase in velocity due to the existence of the superstructure. A reduction in self-noise of the mast structure has been aimed by reducing flow separation and vorticity. Time-dependent velocity data obtained with scale-resolving simulations are presented for the evaluation of helicopter landings. The capabilities and limitations of the RANS technique are discussed along with recent developments in modeling approaches.
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Keipour, Azarakhsh, Guilherme A. S. Pereira, Rogerio Bonatti, Rohit Garg, Puru Rastogi, Geetesh Dubey und Sebastian Scherer. „Visual Servoing Approach to Autonomous UAV Landing on a Moving Vehicle“. Sensors 22, Nr. 17 (30.08.2022): 6549. http://dx.doi.org/10.3390/s22176549.
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Many aerial robotic applications require the ability to land on moving platforms, such as delivery trucks and marine research boats. We present a method to autonomously land an Unmanned Aerial Vehicle on a moving vehicle. A visual servoing controller approaches the ground vehicle using velocity commands calculated directly in image space. The control laws generate velocity commands in all three dimensions, eliminating the need for a separate height controller. The method has shown the ability to approach and land on the moving deck in simulation, indoor and outdoor environments, and compared to the other available methods, it has provided the fastest landing approach. Unlike many existing methods for landing on fast-moving platforms, this method does not rely on additional external setups, such as RTK, motion capture system, ground station, offboard processing, or communication with the vehicle, and it requires only the minimal set of hardware and localization sensors. The videos and source codes are also provided.
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Li, Guoqiang, Qing Wang, Qijun Zhao, Guoqing Zhao, Fei Feng und Linxin Wu. „A Research on Rotor/Ship Wake Characteristics under Atmospheric Boundary Layer Conditions“. Aerospace 10, Nr. 9 (18.09.2023): 816. http://dx.doi.org/10.3390/aerospace10090816.
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The environment for the shipboard landing and takeoff of helicopters is extremely complex and significantly affects their safe flight. To address the intricate characteristics of the flow field during these operations, a simulation method suitable for rotor/ship wake vortex interaction is developed. This method couples the Delayed Detached Eddy Simulation (DDES) method and the momentum source method. The simulation of flow field characteristics of the SFS2 ship model under different conditions reveals that, in a rotor/ship coupling scenario, the inflow velocity in the wake zone of the flight deck is distributed in a “W” shape due to the influence of the rotor blade tip vortex. Under wind shear conditions, the rotor’s influence on the wake is reduced, resulting in smaller velocity fluctuations compared to uniform inflow conditions. Moreover, the detached eddy is suppressed to some extent. It can be concluded that shear flow mitigates the unsteady characteristics of the ship’s wake zone to some extent, which is beneficial to helicopter operations during takeoff and landing.