Development of Handling Qualities Criteria for Rotorcraft with Externally Slung Loads

Piloted simulations were performed on the NASA-Ames Vertical Motion Simulator (VMS) to explore handling qualities issues for large cargo helicopters, particularly focusing on external slung load operations. The purpose of this work was based upon the need to include handling qualities criteria for cargo helicopters in an upgrade to the U.S. Army's rotorcraft handling qualities specification, Aeronautical Design Standard-33 (ADS-33E-PRF). From the VMS results, handling qualities criteria were developed fro cargo helicopters carrying external slung loads in the degraded visual environment (DVE). If satisfied, these criteria provide assurance that the handling quality rating (HQR) will be 4 or better for operations in the DVE, and with a load mass ratio of 0.33 or less. For lighter loads, flying qualities were found to be less dependent on the load geometry and therefore the significance of the criteria is less. For heavier loads, meeting the criteria ensures the best possible handling qualities, albeit Level 2 for load mass ratios greater than 0.33

Dynamics Modeling and Control of a Quadrotor with Swing Load

Nowadays, aerial robots or Unmanned Aerial Vehicles (UAV) have many applications in civilian and military fields. For example, of these applications is aerial monitoring, picking loads and moving them by different grippers. In this research, a quadrotor with a cable-suspended load with eight degrees of freedom is considered. The purpose is to control the position and attitude of the quadrotor on a desired trajectory in order to move the considered load with constant length of cable. So, the purpose of this research is proposing and designing an antiswing control algorithm for the suspended load. To this end, control and stabilization of the quadrotor are necessary for designing the antiswing controller. Furthermore, this paper is divided into two parts. In the first part, dynamics model is developed using Newton-Euler formulation, and obtained equations are verified in comparison with Lagrange approach. Consequently, a nonlinear control strategy based on dynamic model is used in order to control the position and attitude of the quadrotor. The performance of this proposed controller is evaluated by nonlinear simulations and, finally, the results demonstrate the effectiveness of the control strategy for the quadrotor with suspended load in various maneuvers

Machine learning techniques to estimate the dynamics of a slung load multirotor UAV system

This thesis addresses the question of designing robust and flexible controllers to enable autonomous operation of a multirotor UAV with an attached slung load for general cargo transport. This is achieved by following an experimental approach; real flight data from a slung load multirotor coupled system is used as experience, allowing for a computer software to estimate the pose of the slung in order to propose a swing-free controller that will dampen the oscillations of the slung load when the multirotor is following a desired flight trajectory. The thesis presents the reader with a methodology describing the development path from vehicle design and modelling over slung load state estimators to controller synthesis. Attaching a load via a cable to the underside of the aircraft alters the mass distribution of the combined "airborne entity" in a highly dynamic fashion. The load will be subject to inertial, gravitational and unsteady aerodynamic forces which are transmitted to the aircraft via the cable, providing another source of external force to the multirotor platform and thus altering the flight dynamic response characteristics of the vehicle. Similarly the load relies on the forces transmitted by the multirotor to alter its state, which is much more difficult to control. The principle research hypothesis of this thesis is that the dynamics of the coupled system can be identified by applying Machine Learning techniques. One of the major contributions of this thesis is the estimator that uses real flight data to train an unstructured black-box algorithm that can output the position vector of the load using the vehicle pose and pilot pseudo-controls as input. Experimental results show very accurate position estimation of the load using the machine learning estimator when comparing it with a motion tracking system (~2% offset). Another contribution lies in the avionics solution created for data collection, algorithm execution and control of multirotor UAVs, experimental results show successful autonomous flight with a range of algorithms and applications. Finally, to enable flight capabilities of a multirotor with slung load, a control system is developed that dampens the oscillations of the load; the controller uses a feedback approach to simultaneously prevent exciting swing and to actively dampen swing in the slung load. The methods and algorithms developed in this thesis are validated by flight testing

Airlift operations modeling using Discrete Event Simulation (DES)

The recently completed integrated project by the Systems Engineering and Analysis Cohort 15 at NPS has devised a regional Maritime Theater Security Force to conduct Phase Zero operations based on a tasking from OPNAV N8F. The force's airlift capability was identified as a critical component in the accomplishment of the missions and the required force structure was determined using a mix of mathematical and linear optimization modeling. The goal for this thesis is to develop a stochastic model using Discrete Event Simulation (DES) that can be employed to analyze the devised force structure's airlift operation performance at the operational/tactical level to augment the analysis work performed under that project. The intent is to provide a more complete solution for any stakeholders who want to take the project further to the next level. The resulting model demonstrates the ability to measure the airlift operation performance and provide insights into the operation workflow efficiency. The experiments conducted support the earlier findings on the devised Phase Zero force's ability to meet the most stringent mission requirements but suggested a different maximum airlift capability.http://archive.org/details/airliftoperation109454442Singapore Defence Science and Technology Agency author (civilian).Approved for public release; distribution is unlimited

Payload's sway angle measurement for container in the crane system based on remote sensing

The demand for a high quickly measuring angle in the port crane system should be considered when the container has been transferred from one place to another place. It is significant to build the feedback linking of payload's angle in the integrated crane system. The value of accurate measurement of the angle can be used to optimize the crane control system. In this context, the design and implementation of the experimental setup associated with emulated cranes will be carried out. Several solutions for remote angle measurement were considered one of the considered solutions being represented by millimeter microwave radar sensors. Special developments of algorithms to calculate the sway angle of payload or container were considered as so as the real-time processing using Arduino Uno computation platform. The following objectives were successfully reached. 1. Development of remote sensing system for payload's swing angle measurement considering radars such the sensing devices; 2. Development of a novel angle algorithm measurement and real-time processing of data; 3. Development of a prototype characterized by real-time processing and remote detection capabilities considering short-range and long-range measurements, such as lidar sensor or radar sensor.A demanda por um ângulo de medição rápido e alto no sistema de guindaste portuário deve ser considerada quando o contêiner for transferido de um local para outro. É significativo construir a ligação de feedback do ângulo da carga útil no sistema de guindaste integrado. O valor da medição precisa do ângulo pode ser usado para otimizar o sistema de controle do guindaste. Neste contexto, será realizada a concepção e implementação da configuração experimental associada a gruas emuladas. Diversas soluções para medição remota de ângulos foram consideradas uma das soluções consideradas sendo representadas por sensores de micro-ondas milimetrados. Desenvolvimentos especiais de algoritmos para calcular o ângulo de oscilação da carga útil ou contêiner foram considerados, assim como o processamento em tempo real usando a plataforma de computação Arduino Uno. Os seguintes objetivos foram alcançados com sucesso. 1. Desenvolvimento de sistema de sensoriamento remoto para medição do ângulo de oscilação da carga útil considerando radares como os dispositivos de detecção; 2. Desenvolvimento de um novo algoritmo de medição de ângulos e processamento de dados em tempo real; 3. Desenvolvimento de um protótipo caracterizado por processamento em tempo real e capacidade de detecção remota considerando medições de curto e longo alcance, como sensor LIDAR ou sensor de radar

Voyager support study - Implementation definition Final report

Voyager project implementation definitio