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    Normal vortex interaction with a loaded symmetrical blade
    ( 1999) Doolan, C.J. ; Coton, F.N. ; Galbraith, R.A.McD.
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    Active vibration control for the Kazan Ansat
    ( 2018) Kindereit, B. ; Bachmeyer, P. ; Bondoux, A. ; Swanson, D. ; Bushuev, A.
    This paper presents a high-level overview of the implementation and the results of LORD's OMNI Active Vibration Control System (AVCS) on Russian Helicopter's Ansat helicopter platform as well as a brief description of principles of the technology. The AVCS is designed so that it can be easily adapted to both existing production aircraft and new aircraft development to actively reduce in-flight vibration levels. Vibration reduction allows for increased crew comfort, reduced equipment fatigue and in certain cases even an increased flight envelope at minimal installation weight versus performance compared to other vibration reduction technologies. The technology is architected with a high degree of modularity to allow it to be adapted to a wide variety of aircraft and customer use-cases. The primary goal on the Ansat was to configure the AVCS to reduce vibration levels at the VIP seats in the aft cabin although cockpit vibration levels were also to be considered. LORD engineers worked with the Russian Helicopters team at the Kazan, Russia facility to integrate and tune the system through simulation and flight test, which resulted in reductions in vibration levels at the VIP seats of up to 84% depending on flight condition. Ultimately, these efforts resulted in two production configurations, which first appeared on a production Ansat in February 2018, making it the first Russian helicopter with LORD's Active Vibration Control technology.
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    Development of a civil light helicopter flight simulator for pilot training
    ( 2018) Kazenmaier, U. ; Gerboni, C.A. ; Geluardi, S. ; Olivari, M. ; Richter, T. ; Fichter, W. ; Bülthoff, H.H.
    This paper aims at defining the necessary characteristics to develop a reliable and cheap helicopter flight simulator that could be used in flight schools for pilot training. The main contribution is the definition of helicopter dynamics and model parameters that are necessary to reproduce those characteristics perceivable by a pilot in a simulated environment. From this analysis, a physical-based nonlinear helicopter model is implemented. The proposed model description allows helicopter flight characteristics to be modified by changing only few physical parameters, which are readily accessible. The helicopter model is integrated with commercially available off-the-shelf helicopter controls and a Virtual Reality headset to create a cheap fixed-based simulator. The helicopter simulator is then validated through a pilot in-the-loop experiment with five licensed helicopter pilots. Subjective as well as objective metrics are considered for the evaluation. Results suggest that the proposed flight simulator can be effectively used in flight schools to save flight hours for the training of novice pilots. However, for training expert pilots a more complex setup would be necessary, able to provide additional features like the motion cueing.
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    The elevated helipads - Study of wind and rotor wash influence for most common configuration types
    ( 2018) Dziubi?ski, A. ; Sieradzki, A. ; Żurawski, R.
    Problem of lack of possible places to build new buildings is well known in modern cities. When it concerns helipads, which need large area to be placed and also it have to be carefully checked, how surroundings is influencing on this new construction, the case is even more complicated, because those sites have to fulfil demanding regulations. For hospital helipads it is necessary to have possible quickest way from helicopter to surgery. When area is limited, it is usually necessary to place such construction on a building and such helipad is then called elevated. However no document can provide a strict information, how to place new helipad in its surrounding - only general data is available. Too many factors have to be considered. This is why always a detailed analysis is needed in order to be sure, that flight operations can be done safely. This paper presents the work flow concerning this topic, from regulations to fulfil to results of analysis. Some aspects of different locations and its influence on elevated helipads are discussed. Also details about performing the analysis are presented.
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    Embedding intelligent image processing algorithms: The new safety enhancer for helicopters missions
    ( 2018) Zoppitelli, P. ; Mavromatis, S. ; Sequeira, J. ; Anoufla, G. ; Belanger, N. ; Filias, F.X.
    Over the last two decades, image processing technologies rapidly emerged from the shadows to become one of the most important field of interest in computer science. Although image analysis is a hot topic in the automobile industry and for some aircraft applications (drones, airplane, space probes...), the certification of any vision based autopilot system for helicopter missions remains an ongoing challenge. Indeed, such a system would be required to perform complex missions with a high success rate while possibly facing adverse weather conditions. However the rapid increase of processing power, the development of image analysis algorithms, as well as the miniaturization of high resolution cameras, are allowing new technical solutions for autonomous flight. Facing this new technological deal, helicopters manufacturers can no longer ignore that vision based systems are about to become a key enhancer for versatile rotorcraft missions. Airbus Helicopters is committed to put the safety of its aircrafts at the highest standards. For this purpose, Airbus Helicopters has initiated the development of advanced systems integrating many disciplines like sensor acquisition, scene understanding, situation awareness, and artificial intelligence. As a contribution to this company objective, the EAGLE project (Eye for Autonomous Guidance and Landing Extension) was launched 2 years ago to develop a generic optronic platform facilitating integrations of algorithms for different applications. The system aims to improve safety and reduce the pilots� workload during flights in oil and gas and SAR missions. This paper presents the latest results that have been obtained by Airbus Helicopters and the LIS-lab in the development of a landing platform detector in the frame of this project. We will first introduce the general methodology applied for the determination of the platform position. The approach is hierarchical and based on a collection of hints to determine, refine and validate suitable locations for the presence of a helipad. We will then present the strategy for the selection of regions of interest. The aim is both to determine the right size of portion of the image to be analyzed, and to enable the real-time adaptation of the selection and sequencing of the regions to be explored. This article will then detail the methods used to determine the areas susceptible to contain a landing platform. The algorithm mainly relies on flat ellipse detection as it is the most visible feature of a helipad seen from long distances. An adaption of the Hough transform proved to be the most reliable method in the specific case of very flat ellipses. A validation step using many other properties and visual clues performs the verification of the presence of the helicopter landing platform in the research areas delimited by the obtained ellipses. Having presented the algorithm for the detection of a helicopter landing platform, we will discuss some approaches to increase the system�s accuracy, robustness and integrity (detection of failure). In particular, safety and certification considerations are used to select the human-machine interfaces and overall design of the system. A result section will show how this system demonstrated to be capable of detecting landing platforms from a distance of 1500 meters and tracking it without interruption until the landing phase. Last but not least, this paper will introduce an open view of identified image processing technologies continued path for the upcoming years. Our vision of this technological field as a mandatory brand new core competency to be strengthened within Airbus Helicopters, and the way we intend to build up the necessary ecosystem with Airbus� other business units, will be the epilogue of the article.