International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the development of a compact mobile telemetry system using commercial-off-the-shelf components. The personal computer-based systems support microwave pulse code modulation and serial spread-spectrum radio modem telemetry. The mobile ground station provides data display and archiving of test activities, air-ground communications between experimenters and the flight test crew, and acts as a flight test Differential Global Positioning System base station. The success of the systems indicates that functional telemetry capabilities can be established for small flight test programs at modest cost.

Submitted in fulfillment of the requirements for the degree of Master of Technology: Emergency Medical Care, Durban University of Technology, Durban, South Africa, 2015. / Introduction: A Helicopter Emergency Medical Service (HEMS) is a specialist flying emergency service where on-board medical personnel have both the knowledge and equipment to perform complicated medical procedures. There is an absence of literature describing the types of patients treated and the clinical outcome of these patients flown by Helicopter Emergency Medical Services within South Africa. The paucity of literature on this topic poses a challenge for current aeromedical services as there is no baseline information on which to base flight criteria, staffing and policy documents. This has the potential to hamper the advancement of HEMS within South Africa. Purpose of the study: The purpose of this study was to undertake a descriptive analysis of the patients flown by the Netcare 911 HEMS over a 12 month period in both Gauteng and KwaZulu-Natal and to assess the patients’ outcomes. The objectives of the study were to analyse the clinical demographics of patients transported by the Netcare 911 HEMS operation, determine the time frames from dispatch of the helicopter to delivery of the patient to the receiving hospital and undertake a correlational analysis of crew qualifications, clinical procedures performed and their outcomes at 24 hours and 72 hours. A further objective was to make recommendations regarding the refinement of current aeromedical policies as well as the education and training requirements. Methodology: The research study was conducted utilizing a retrospective quantitative, descriptive design to undertake an analysis of patients transported by a private helicopter emergency medical service within South Africa. The records of all patients transported by the Netcare 911 HEMS operations between 01 January 2011 and 31 December 2011 were included. Results: In the 12 month study period there were a total of 547 cases. However, the final study population was made up of 537 cases as 10 cases had to be excluded due to incomplete documentation. Of the 537 cases, 82 (15.3%) were managed by the KwaZulu-Natal HEMS and 455 (84.7%) were managed by the Gauteng HEMS. Findings revealed that the majority of patients flown in both Gauteng and KwaZulu-Natal were adult males: males (n=398; 74.1%) and adults (n=437; 81.4%). Motor vehicle accidents were the most common incident type for both operations (n=193; 36%). At the 24-hour follow up, 339 (63.1%) patients were alive and stable and at the 72-hour follow up, 404 (75.3%) were alive and stable. Conclusion and recommendations The findings of this study provide valuable information that may have an impact on the current staffing and authorization criteria of South African HEMS operations.

This thesis presents the development of self adaptive flight controller for an unmanned helicopter system under hovering manoeuvre. The neural network (NN) based model predictive control (MPC) approach is utilised in this work. We use this controller due to its ability to handle system constraints and the time varying nature of the helicopter dynamics. The non-linear NN based MPC controller is known to produce slow solution convergence due to high computation demand in the optimisation process. To solve this problem, the automatic flight controller system is designed using the NN based approximate predictive control (NNAPC) approach that relies on extraction of linear models from the non-linear NN model at each time step. The sequence of control input is generated using the prediction from the linearised model and the optimisation routine of MPC subject to the imposed hard constraints. In this project, the optimisation of the MPC objective criterion is implemented using simple and fast computation of the Hildreth's Quadratic Programming (QP) procedure. The system identification of the helicopter dynamics is typically performed using the time regression network (NNARX) with the input variables. Their time lags are fed into a static feed-forward network such as the multi-layered perceptron (MLP) network. NN based modelling that uses the NNARX structure to represent a dynamical system usually requires a priori knowledge about the model order of the system. Low model order assumption generally leads to deterioration of model prediction accuracy. Furthermore, massive amount of weights in the standard NNARX model can result in an increased NN training time and limit the application of the NNARX model in a real-time application. In this thesis, three types of NN architectures are considered to represent the time regression network: the multi-layered perceptron (MLP), the hybrid multi-layered perceptron (HMLP) and the modified Elman network. The latter two architectures are introduced to improve the training time and the convergence rate of the NN model. The model structures for the proposed architecture are selected using the proposed Lipschitz coefficient and k-cross validation methods to determine the best network configuration that guarantees good generalisation performance for model prediction. Most NN based modelling techniques attempt to model the time varying dynamics of a helicopter system using the off-line modelling approach which are incapable of representing the entire operating points of the flight envelope very well. Past research works attempt to update the NN model during flight using the mini-batch Levenberg-Marquardt (LM) training. However, due to the limited processing power available in the real-time processor, such approaches can only be employed to relatively small networks and they are limited to model uncoupled helicopter dynamics. In order to accommodate the time-varying properties of helicopter dynamics which change frequently during flight, a recursive Gauss-Newton (rGN) algorithm is developed to properly track the dynamics of the system under consideration. It is found that the predicted response from the off-line trained neural network model is suitable for modelling the UAS helicopter dynamics correctly. The model structure of the MLP network can be identified correctly using the proposed validation methods. Further comparison with model structure selection from previous studies shows that the identified model structure using the proposed validation methods offers improvements in terms of generalisation error. Moreover, the minimum number of neurons to be included in the model can be easily determined using the proposed cross validation method. The HMLP and modified Elman networks are proposed in this work to reduce the total number of weights used in the standard MLP network. Reduction in the total number of weights in the network structure contributes significantly to the reduction in the computation time needed to train the NN model. Based on the validation test results, the model structure of the HMLP and modified Elman networks are found to be much smaller than the standard MLP network. Although the total number of weights for both of the HMLP and modified Elman networks are lower than the MLP network, the prediction performance of both of the NN models are on par with the prediction quality of the MLP network. The identification results further indicate that the rGN algorithm is more adaptive to the changes in dynamic properties, although the generalisation error of repeated rGN is slightly higher than the off-line LM method. The rGN method is found capable of producing satisfactory prediction accuracy even though the model structure is not accurately defined. The recursive method presented here in this work is suitable to model the UAS helicopter in real time within the control sampling time and computational resource constraints. Moreover, the implementation of proposed network architectures such as the HMLP and modified Elman networks is found to improve the learning rate of NN prediction. These positive findings inspire the implementation of the real time recursive learning of NN models for the proposed MPC controller. The proposed system identification and hovering control of the unmanned helicopter system are validated in a 6 degree of freedom (DOF) safety test rig. The experimental results confirm the effectiveness and the robustness of the proposed controller under disturbances and parameter changes of the dynamic system.

The Chromakey Augmented Virtual Environment (ChrAVE) 3.0 System is a training system created to augment initial, refresher, and proficiency training in helicopter aviation using accurate simulation. Designed around advanced chromakey technologies, this system is deployable, scalable, and flexible, allowing for use in austere environments such as aboard ship or in forward deployed locations. The goal of system development was to prove that a collection of commercially available components could be integrated along with the Virtual Environment Helicopter (VEHELO) 2.0 software package in order to provide a realistic simulated environment in which pilots can practice skill sets that are critical to mission success. The focus of this thesis is the validation of ChrAVE 3.0 as an augmented trainer that can be adapted for use inside an actual aircraft cockpit. By placing the pilot in the most realistic simulation available ChrAVE 3.0 will enhance development of skills such as Terrain Appreciation, Crew Resource Management (CRM), and Situational Awareness (SA). Continuing past research, this thesis will analyze empirical data collected from training flights to further prove its value as an instructional tool. ChrAVE 3.0 is housed in three man-portable containers and can be set up within minutes with little or no prior experience.

This study investigates the possibilities for implementation of speech recognition software in order to ease the usage of a Virtual Reality Simulator. The Pitch Door-Gunner simulator is described followed by a general discussion about simulator and simulator environments. Previous research and theories regarding speech recognition technology are presented, and relevant aspects for training effects such as stress are accounted for. Interviews are conducted with military personnel in order to better grasp how the simulator is actually used and how it can be used to elicit learning. An implementation with a subsequent feasibility test is conducted to investigate practical limitations and give more insight into the possibilities regarding the usage of speech recognition in the simulator. The results show that it is feasible to use speech recognition software to control simple functions, more elaborate functionality requires further research. Furthermore, the study discusses which functions would be favourable to control considering the pros and cons of speech recognition. It is suggested that speech recognition can be important as a tool to make usage more convenient and as a tool to support the instructor, for example, by bookmarking certain segments of training for later review with the help of voice-commands.

O uso de materiais inteligentes em problemas de controle de vibração tem sido investigado em diversas pesquisas ao longo dos últimos anos. Apesar de que diferentes materiais inteligentes estão disponíveis, o piezelétrico tem recebido grande atenção devido à facilidade de uso como sensores, atuadores, ou ambos simultaneamente. As principais técnicas de controle usando materiais piezoelétricos são os ativos e passivos. Circuitos piezelétricos passivos são ajustados para uma frequência específica e, portanto, a largura de banda efetiva é pequena. Embora os sistemas ativos possam apresentar um bom desempenho no controle de vibração, a quantidade de energia externa e hardware adicionado são questões importantes. As técnicas SSD (Synchronized Switch Damping) foram desenvolvidas como uma alternativa aos controladores passivos e controladores ativos de vibração. Elas podem ser técnicas semi-ativas ou semi-passivas que introduzem um tratamento não linear na tensão elétrica proveniente do material piezelétrico e induz um aumento na conversão de energia mecânica para energia elétrica e, consequentemente, um aumento no efeito de amortecimento. Neste trabalho, o controle piezoelétrico semi-passivo de uma pá piezelétrica engastada é apresentado e comparado com outros controladores. O modelo não linear electromecânico de uma pá com piezocerâmicas incorporados é determinado com base no método variacional-assintótico (VAM). O sistema rotativo acoplado não linear é resolvido no domínio do tempo, utilizando um método de integração alfa-generalizado afim de garantir a estabilidade numérica. As simulações são realizadas para uma vasta gama de velocidades de rotação. Em primeiro lugar, um conjunto de resistências (variando desde a condição de curto-circuito para a condição de circuito aberto) é considerada. O efeito da resistência ótima (que resulta em máximo amortecimento) sobre o comportamento do sistema é investigado para o aumento da velocidade de rotação. Mais tarde, a técnica SSDS é utilizada para amortecer as oscilações da pá com o aumento da velocidade de rotação. Os resultados mostram que a técnica SSDS pode ser um método útil para o controle de vibrações de vigas rotativas não lineares, tais como pás de helicóptero. / The use of smart materials in vibration control problems has been investigated in several researches over the last years. Although dierent smart materials are available, the piezoelectric one has received great attention due to ease of use as sensors, actuators, or both. The main control techniques using piezoelectric materials are the active and passive ones. Passive piezoelectric networks are adjusted for specic target frequencies and, therefore, the eective bandwidth of such systems is small. Although active systems can achieve good vibration control performance, the amount of external power and added hardware are important issues. The synchronized switch damping (SSD) technique was developed in order to address the issues of passive damping methodologies as well as the issues of active control systems. The SSD can be classied as semi-passive technique or semi-active technique that introduce the nonlinear treatment of the piezoelectric element voltage output and induce an increase in mechanical to electrical energy conversion and, consequently, the shunt damping eect. In this work, the semi-passive piezoelectric control of a rotating cantilever beam response is presented and compared with other controllers. The nonlinear electromechanical model of a rotating beam with embedded piezoceramics is derived based on the variational-asymptotic method (VAM). The coupled non-linear rotary system is solved in the time-domain by using a generalized-alpha integration method in order to guarantee numerical stability. The simulations are performed for a wide range of rotating speeds. First, a set of load resistances (ranging from short circuit condition to open circuit condition) is considered. The eect of optimum load resistance (for maximum damping) on the elastic behavior of the beam is investigated for increasing rotating speed. Later, the synchronized switch damping on short (SSDS) technique is employed to damp the nonlinear oscillations of the rotating beam with increasing rotating speed. Results show that the SSDS technique can be a useful method of control for nonlinear rotating beams such as helicopter blades.

Este trabalho aborda o estudo de um sistema de referência inercial de posição e atitude e um sistema de controle para um helicóptero autônomo utilizando, como base para formulação e testes, o modelo linearizado da aeronave Yamaha R-MAX. Um sistema de referência inercial (INS) e um sistema de referência de atitude e orientação (AHRS) são utilizados para estimar a posição e atitude da aeronave, e estimadores robustos baseados no filtro de Kalman são empregados para minimizar os efeitos de incertezas paramétricas. É utilizada uma estratégia de controle em cascata com três malhas consistindo de uma malha interna para garantir a estabilidade do helicóptero (são utilizadas as técnicas LQR e H \'INFINITO\', separadamente), uma malha intermediária baseada em linearização por realimentação (FLC) para desacoplar os pares entrada/saída e uma malha externa baseada em um controlador proporcional-derivativo (PD) para permitir o rastreamento da trajetória. Resultados de simulação são apresentados para avaliar o desempenho de cada abordagem. / This work concerns the study of an inertial reference system and a control system for an autonomous helicopter using, as basis for the formulation and testing, the linearized mo del of the aircraft Yamaha R-MAX. An inertial navigation system (INS) and an attitude and orientation reference system (AHRS) are used to estimate the position and attitude of the aircraft and robust estimators based on Kalman filter are employed to minimize the effects of parametric uncertainties. A cascaded control architecture with three control methodologies is used, consisting of an inner-loop to ensure stability of the helicopter (the LQR and H \'INFINITE\' techniques are used, separately), a mid-loop based on linearization feedback (FLC) to decouple the dynamics ofthe lateral, longitudinal, vertical and heading axes and an outer-loop based on a proportional-derivative (PD) controller to enable trajectory tracking. Simulation results are presented to evaluate the performance of each approach.

The aim of the thesis is to create a business plan for the helicopter school HELITOM s.r.o. The first part is theoretically oriented and explains what a business plan is, what are the basic procedures for the assembly. Further theoretical section describes the specifics of the business in a helicopter flying, especially legislation. The practical part consists of the actual business plan. In the business plan there was made, among other things, competition analysis and analysis of potential risks. The financial plan was drawn up in another part of the Thesis and is processed alternatively for three possible scenarios for the future development.

Este trabalho apresenta uma abordagem para a identificação da dinâmica não linear do modelo matemático de uma pá de helicóptero em rotação. Durante a simulação, foi considerado o helicóptero em voo pairado. Foi usada a representação bilinear para o modelo, uma das formas mais simples de representação de um modelo não linear. O modelo matemático da pá foi implementado através do método de elementos finitos e simulado em ambiente Matlab. Foi suada na identificação, uma rede neural artificial como técnica não convencional, já que demonstra grande capacidade de aproximação de modelos não lineares, grande desempenho em análise da dinâmica de sistemas flexíveis e implementação e rapidez consideráveis. As redes neurais com processamento temporal são usadas para aproximar componentes da dinâmica não linear sobre um conjunto de entradas prescritas, e são usadas em simulação como meio rápido de obter a resposta no tempo. Para capturar a natureza recursiva dos componentes dinâmicos do sistema foi usada uma rede feedforward com processamento temporal, com uma camada intermediária de neurônios e com entradas na rede atrasadas. Para verificar o desempenho da rede, foi feita a comparação entre os dados de simulação obtidos originalmente e os dados resultantes de simulação da rede. Este trabalho foi desenvolvido visando futuramente aplicação de técnicas de controle de vibrações em pás rotativas. / This work presents an approach for non-linear dynamics identification of a rotating helicopter blade mathematical model. During simulation, the helicopter was considered in hovering flight. A bilinear representation was used for the model, since it is known as one of the simplest forms of representation of a non linear model. Mathematical model of blade was implemented using finite elements method and simulated in Matlab. A neural network is used in the identification process as a non conventional technique, since it demonstrates good capacity for approximation non-linear models and good performance in terms of the analysis of the dynamics of flexible systems. It also presents good performance in terms of implementation and processing speed. The neural networks with time dependent processing are used to approximate the components of the non-linear dynamics over a prescribed inputs set, and they are used in simulation as a rapid way of obtaining the time response. In order to capture the recursive nature of the dynamic components of the system, a feedforward network with time dependent processing, with an intermediate layer of neurons and delayed inputs is used. The performance of the net was verified comparing the results obtained originally by simulation with those resulting from the network emulation. This work was developed in order to apply vibration control techniques to rotating blades.

Este trabalho apresenta uma abordagem para a identificação da dinâmica não linear do modelo matemático de uma pá de helicóptero em rotação. Durante a simulação, foi considerado o helicóptero em voo pairado. Foi usada a representação bilinear para o modelo, uma das formas mais simples de representação de um modelo não linear. O modelo matemático da pá foi implementado através do método de elementos finitos e simulado em ambiente Matlab. Foi suada na identificação, uma rede neural artificial como técnica não convencional, já que demonstra grande capacidade de aproximação de modelos não lineares, grande desempenho em análise da dinâmica de sistemas flexíveis e implementação e rapidez consideráveis. As redes neurais com processamento temporal são usadas para aproximar componentes da dinâmica não linear sobre um conjunto de entradas prescritas, e são usadas em simulação como meio rápido de obter a resposta no tempo. Para capturar a natureza recursiva dos componentes dinâmicos do sistema foi usada uma rede feedforward com processamento temporal, com uma camada intermediária de neurônios e com entradas na rede atrasadas. Para verificar o desempenho da rede, foi feita a comparação entre os dados de simulação obtidos originalmente e os dados resultantes de simulação da rede. Este trabalho foi desenvolvido visando futuramente aplicação de técnicas de controle de vibrações em pás rotativas. / This work presents an approach for non-linear dynamics identification of a rotating helicopter blade mathematical model. During simulation, the helicopter was considered in hovering flight. A bilinear representation was used for the model, since it is known as one of the simplest forms of representation of a non linear model. Mathematical model of blade was implemented using finite elements method and simulated in Matlab. A neural network is used in the identification process as a non conventional technique, since it demonstrates good capacity for approximation non-linear models and good performance in terms of the analysis of the dynamics of flexible systems. It also presents good performance in terms of implementation and processing speed. The neural networks with time dependent processing are used to approximate the components of the non-linear dynamics over a prescribed inputs set, and they are used in simulation as a rapid way of obtaining the time response. In order to capture the recursive nature of the dynamic components of the system, a feedforward network with time dependent processing, with an intermediate layer of neurons and delayed inputs is used. The performance of the net was verified comparing the results obtained originally by simulation with those resulting from the network emulation. This work was developed in order to apply vibration control techniques to rotating blades.