Helicopter Flight Simulator Research Articles

Simulation-Based Helicopter Mission Effectiveness Evaluation Method

It is always difficult to obtain a reliable result of helicopter mission effectiveness evaluation (HMEE) by traditional methods. In order to solve the problem, this paper compared and analysed advantages and disadvantages of traditional effectiveness evaluation methods, and presented a simulation-based helicopter mission effectiveness evaluation method. The method is based on the simulation data. The method combines with advantages of multi parameter evaluation method, computer simulation evaluation method and logarithmic evaluation method. By using the reliable helicopter flight simulation data and an objective weight coefficient calculation methods, we can get accurate and reliable helicopter mission effectiveness value. Research proves that this method can be applied in the field of effectiveness evaluation.

A novel classification method for driving simulators based on existing flight simulator classification standards

As technology has advanced and costs have fallen, the advantages of using simulators to train for safe, economical, and environmentally friendly driving have become more apparent. The need for a driving simulator classification arises from understanding and comparing simulator capabilities and options; however, only a limited number of studies have been conducted related to classification, calling for determination of methods and criteria. In this study, a classification method for driving simulators is proposed by adapting criteria for helicopter flight simulation training devices in which established methods of classification are defined by international and national regulators such as the Joint Aviation Authorities and Federal Aviation Administration. In the proposed method, the level of a simulator is determined by taking general characteristics under consideration, such as motion, visual, and sound systems. Through a case study, the method was applied to determine the class of a specific truck simulator.

Validation of mathematical models for helicopter flight simulators past, present and future challenges

AbstractAt the heart of a flight simulator resides the mathematical representation of aircraft behaviour in response to control inputs, atmospheric disturbances and system inputs including failures and malfunctions. While this mathematical model can never be wholly accurate, its fidelity, in comparison with real world behaviour, underpins the usefulness of the flight simulator. The present paper examines the state of the art achieved in validating mathematical models for helicopter simulators, addressing the strengths and weaknesses of the present European standard for the qualification of helicopter flight simulators, JAR FSTD-H (previously JAR-STD-1H/2H/3H). Essential questions are examined, such as: What is the required model fidelity to guarantee a simulation is sufficiently representative to be fit for purpose? Are the tolerances set in the current standards fine enough that they lead to only minor changes in handling qualities? What is an acceptable tuning process for the simulation? What is the effect of modelling fidelity on the overall pilot control strategy? What is the relationship between the settings of the simulator cueing environment and the behaviour of the pilot? What is the industrial experience on qualification of flight simulators that might usefully inform developments? Many of these questions were addressed in Europe in a previous GARTEUR Action Group (AG) HC/AG-12 the results of which are documented in this paper. Solutions are proposed for improving the current JAR-FSTD standard with respect to validation of mathematical models.

Rotor unsteady aerodynamics model using an efficient free‐vortex method

PurposeThe purpose of this paper is to present and validate an efficient time‐marching free‐vortex method for rotor wake analysis and study the rotor wake dynamics in transient and maneuvering flight conditions.Design/methodology/approachThe rotor wake is represented by vortex filament elements. The equations governing the convection, strain and viscous diffusion of the vortex elements are derived from incompressible Navier‐Stokes equations based on the viscous splitting algorithm. The initial core size of the blade tip vortices is directly computed by a vortex sheet roll‐up model. Then, a second‐order time‐marching algorithm is developed for solving the governing equations. The algorithm is formulated in explicit form to improve computing efficiency. To avoid the numerical instability, a high order variable artificial dissipative term is directly introduced into the algorithm. Finally, the developed method is applied to examine rotor wake geometries in steady‐state and maneuvering flight conditions. Comparisons between predictions and experimental results are made for rotor wake geometries, induced inflow distributions and rotor transient responses, to help validate the new method.FindingsThe algorithm is found to be numerically stable and efficient. The predicted rotor responses have good agreement with experimental data. The transient behavior of the wake dominates the rotor responses following rapid control inputs in hover. The wake curvature effect induced by rotor pitching or rolling rate significantly changes the rotor off‐axis response.Research limitations/implicationsThis method should be further validated using experimental measurements of full‐scale helicopter rotors.Originality/valueThe paper presents a new time‐marching free‐vortex wake method, which is suitable for application in helicopter flight simulation.

Objective and subjective evaluations of flight simulator fidelity

There is interest in how pilots perceive simulator fidelity and rate self-performance in virtual reality flight training. Ten participants were trained to perform a target tracking task in a helicopter flight simulation. After training objective performance, the median tracking error, was compared to subjective self-evaluations in a number of flying conditions where the cues available to our pilots were manipulated in a factorial design: the simulator motion platform could be active or static, audio cues signalling the state of the turbine could be those used during training, non-informative, or an obviously different but informative ‘novel’ sound. We tested participants under hard and easy flying conditions. Upon completion of each test condition, participants completed a 12-statement Likert-scale with items concerning their performance and helicopter simulator fidelity. Objective performance measures show that flight performance improved during training and was affected by audio and motion cues. The subjective data shows that participants reliably self-evaluated their own performance and simulator fidelity. However, there were instances where subjective and objective measures of performance or fidelity did not correlate. For example, although participants rated the ‘novel’ turbine sound as having low fidelity, it behaviourally caused no difference with respect to the turbine sound used in training. They were also unable to self-evaluate outcome of learning. We conclude that whilst subjective measures are a good indicator of self-performance, objective data offers a valuable task-oriented perspective on simulator fidelity.

Complementary Information Distribution to Improve Team Performance in Military Helicopter Operations: An Experimental Study

This study compared a complementary information distribution, that is, purposeful distribution to individual crewmembers of the information needed for their individual tasks, to the current distribution where all crewmembers can access all information in the flight deck. The complementary information distribution is intended to foster a complementary mental model that promotes each team member's access to information according to his or her immediate tasks. The hypothesis—that the complementary information distribution would improve performance and team interaction—was tested in a high-fidelity military helicopter flight simulator with 20 Army aviators. The complementary information distribution was found to have no effect or a positive effect (and no negative effects) on measures of individual's task performance and error rates, with greater positive effects on most measures in off-nominal compared to nominal flight conditions. In addition, measures of team communication and awareness of fellow crewmembers' information needs and workload also found only no effect or positive effects with a complementary information distribution.

Evaluation of visual cues of three-dimensional virtual environments for helicopter simulators

Visual cues are an essential part of helicopter flight simulators. The required cues for hover are particularly large, due to closeness to the ground and small movements. However, the research on low-altitude helicopter flight is limited. In this research, the density and height of the three-dimensional (3D) objects in the scene are analysed to find their effect on hovering and low-altitude helicopter flight. An experiment is conducted using a personal computer-based flight simulator on 10 professional military pilots. The results revealed that 3D object density and 3D object height affect both horizontal and vertical hovering performance. In hover and low-altitude flight, altitude control is positively affected by smaller object height. Paradoxically, the pilots preferred the scenes composed of tall and mixture objects. Pilot distance estimation was significantly affected by the knowledge of both object density and object height, but these factors do not individually improve distance estimation.

Transferrable Learning of Multisensory Cues in Flight Simulation

Flight simulators which provide visual, auditory, and kinematic (physical motion) cues are increasingly used for pilot training. We have previously shown that kinematic cues, but not auditory cues, representing aircraft motion improve target tracking performance for novice ‘pilots’ in a simulated flying task (Meyer et al IMRF 2010). Here we explore the effect of learning on task performance. Our subjects were first tested on a target tracking task in a helicopter flight simulation. They were then trained in a simulator-simulator, which provided full audio, simplified visuals, but not kinematic signals to test whether learning of auditory cues is possible. After training we evaluated flight performance in the full simulator again. We show that after 2 hours training auditory cues are used by our participants as efficiently as kinematic cues to improve target tracking performance. The performance improvement relative to a condition where no audio signals are presented is robust if the sound environment used during training is replaced by a very different audio signal that is modulated in amplitude and pitch in the same way as the training signal. This shows that training is not signal specific but that our participants learn to extract transferrable information on sound pitch and amplitude to improve their flying performance.

Visualisation of the brownout phenomenon, integration and test on a helicopter flight simulator

AbstractFlying under degraded visual environments is a challenging task in helicopter operations. The brownout phenomenon, caused by the rotor downwash on a dusty or sandy underground has caused several critical incidences and accidents in the past. In contrast to an extensive free wake analysis of the rotor vortices, this paper presents a computer graphical solution to simulate brownout conditions. The animation approach builds upon a particle system with a basic aerodynamic assumption of a permanent ground vortex and additional turbulence. The created brownout effect module is a part of the RealTime Image Generator software, used in DLR’s ground based helicopter flight simulator. The object oriented structure of the underlying application programming interface OpenSceneGraph facilitates the development of a generic effect interface for future improvements. An overview of the developed module, the particle system engine and the physical dependencies is provided. To overcome the challenge of capturing the visual realism, a pilot test course with brownout typical tasks is presented. Criteria focussing on the visual and physical parameters are defined to build up a questionnaire. It is used to improve the visual standard and to meet the future pilot’s needs.

논문 : 헬리콥터 비행 시뮬레이션을 위한 로터운동방정식 유도

헬리콥터 비행 시뮬레이션을 위한 로터 운동방정식을 implicit formulation 형태로 유도하였다. 좌표계 사이의 상대운동을 고려한 일반화된 벡터 kinematics 를 유도하고 이를 적용하여 브레이드 임의 위치 에서 관성속도 및 관성가속도를 구하였다. 유도된 속도 및 가속도 벡터를 이용하여 플래핑, 리드래그 및 토오크 방정식 등을 implicit form으로 유도하였다. 브레이드 스팬에 따른 공간 적분 방법을 살펴보고, 다양한 힌지형상 및 힌지배열 순서에 관계없이 응용영역을 확장할 수 있음을 밝혔다. DAE(Differential Algebraic Equation) 형태를 갖는 본 연구의 결과식을 이용하여 동특성 계산을 위한 시간적분법을 검토하였다. The implicit formulation of rotor dynamics for helicopter flight simulation has been derived and and presented. The generalized vector kinematics regarding the relative motion between coordinates were expressed as a unified matrix operation and applied to get the inertial velocities and accelerations at arbitaty rotor blade span position. Based on these results the rotor aeromechanic equations for flapping dynamics, lead-lag dynamics and torque dynamics were formulated as an implicit form. Spatial integration methods of rotor dynamic equations along blade span and the expanded applicability of the present implicit formulations for arbitrary hings geometry and hinge sequences have been investigated. Time integration methods for present DAE(Differential Algebraic Equation) to calculate dynamic response calculation are recommenaded as future works.

Wind Model around a High Building for a Helicopter Flight Simulator

Flight simulation tests of a fire helicopter for high buildings are conducted under the cooperative research between the National Aerospace Laboratory and the Tokyo Fire Department. One of the most important factors to realize a fire helicopter is the heavily turbulent wind around buildings which may adversely affect the safety and efficiency during fire fighting. In simulating the mission of the fire helicopter, it is required to generate the wind in real time depending on both time and location of the measuring point. When the height of the building is assumed to be infinite, it is feasible to make such wind by using two dimensional discrete vortex method. It is also shown that this method is applicable to the building whose height is not so longer than its width.

A generic harmonic rotor model for helicopter flight simulation

AbstractA new rotor model for helicopter flight mechanics simulation is presented. The rotor dynamics are described using multiblade coordinates, and the aerodynamic loads include nonlinear effects such as stall and compressibility. These loads are described as harmonic series. The number of harmonics in the series determines the model accuracy. Thus by changing the number of harmonics from one to a large number, it is possible to obtain models that range between a quasi tip path plane approach and an accurate blade element model. The user of the model can very easily change the model accuracy and consequently its efficiency. The new rotor model is investigated and its application for trim and manoeuvre calculations is presented and discussed.

Helmet Mounted Display Systems for Helicopter Simulation

Simulation scientists continually pursue improved flight simulation technology with the goal of closely replicating the “real world” physical environment. The presentation/display of visual information for flight simulation is one such area enjoying recent technical improvements that are fundamental for conducting simulated operations close to the terrain. Detailed and appropriate visual information is especially critical for Nap-Of-the-Earth (NOE) helicopter flight simulation where the pilot maintains an “eyes-out” orientation to avoid obstructions and terrain. This paper elaborates on the visually-coupled Wide Field Of View Helmet Mounted Display (WFOVHMD) system technology as a viable visual display system for helicopter simulation. In addition the paper discusses research conducted on the NASA-Ames Vertical Motion Simulator that examined one critical research issue for helmet mounted displays.

Predictive Performance Models and Multiple Task Performance

This symposium presents five models that predict how performance of multiple tasks will interact in complex task scenarios. The models are discussed, in part, in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are empirically validated in a multitask helicopter flight simulation reported in the present paper. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks. The potential gains to be made multiple resource assumptions remain uncertain.

The development and use of simulators for helicopter flight training in the Royal Navy

Helicopter flight simulators have now been in use in the Royal Navy for fifteen years. The aim of this paper is to discuss the development of the helicopter within naval aviation, and in turn the development of the helicopter simulator alongside its actual aircraft counterpart. The uses to which the Royal Navy puts its simulators will be detailed, with particular reference to its most used simulator, the Sea King Flight and Mission Simulator. The expanding use of helicopters will be discussed, with a look at the Royal Navy’s present day aircraft, the Lynx, and its simulator. The assured future for flight simulation within the Fleet Air Arm will be explained.Helicopters have been used by the Royal Navy since 1944, when four R4s were purchased from Sikorsky’s, and the change over of the Fleet Air Arm from an all fixed wing force to an almost totally helicopter force can be seen to be due to both operational considerations and political events.

The Digital Computer as a Helicopter Flight Simulator

SummaryA method suitable for dealing with extended longitudinal manoeuvres is outlined, based on a step-by-step integration process It is shown how the necessary calculation is carried out on a digital computer, using a programme consisting of two parts A general part is applicable to any manoeuvre, and a special part idealises the pilot's action in performing the particular manoeuvre under consideration Using two illustrative examples, it is demonstrated how the method can be used to deal with problems which usually come under the heading of performance, but nevertheless involve handling qualities Some numerical results aid in the illustration